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  • 101. Andersson, Niclas
    et al.
    Wilson, David
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Validating continuous kraft digester kinetic models with online NIR measurements2002Conference paper (Refereed)
  • 102. Andersson, Niclas
    et al.
    Wilson, David
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Lindström, Tomas
    Organic matter content in black liquor inside and outside chips during kraft cooking2001In: Paperi ja Puu, Vol. vol 83 no 7Article in journal (Refereed)
  • 103.
    Andersson, Ramona
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Självförsörjande småhus med sol- och vindkraft: En simulering av energibehov, analys av miljöpåverkan och ekonomisk hållbarhet2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    One of EU´s biggest goals in climate policy is that carbon emissions shall be reduced by 20% before 2020 to inhibit global warming. By combining renewable energy sources with a more efficient energy system, it could go faster to achieve these goals.

    The purpose of this report is to find out if it is possible to construct a self-sufficient house, located in Karlstad, which uses solar and wind power for its energy demand. The house should not be dependent on the district electricity, but should be able to provide its own energy demand, by being equipped with an energy storage system. To reach the goals of the report an examination of the energy demand for an energy efficient house was made. This was done by comparing the house with a passive house. These calculations were simulated in the program VIP-Energy. The calculations of the solar and wind power were based on the energy demand of the house, and it was supplemented with a pellet stove and battery in order to make it self-sufficient. During the report, an investigation has been made as to the environmental impact of the house compared to an equivalent house that is heated by electricity. An economic analysis has also been calculated for the house.

    The project led to a passive house with a total energy requirement of 11.906 kWh per year. The process required a number of assumptions which may have given rise to some uncertainty in the results. In order to provide the energy need for the house a solar panel system with a maximum power of 12 kW and a wind turbine of 10 kW was chosen. This resulted in an excessive energy production during the summer months and yielded a large surplus of electricity. The solar and wind power generated a total surplus of 18.000 kWh per year. The surplus generated was a consequence of the house intending to be self-sufficient, therefore the calculations was made during the time of year when energy demand was greatest. The system was finally outfitted with a pellet stove and seven sections of 24V batteries with 250Ah/battery.

    The cost analysis estimated an initial cost of solar panels, wind turbine, pellet stove and the batteries. The initial cost was estimated to 403 500 kr and a pellet consumption of about 1000 kr per year. It would take a minimum of 25 years to repay the initial cost if the house was compared to an equivalent house that uses electricity for its energy demand. The amount of carbon dioxide emissions that is prevented compared to an electrically heated house is almost 1000 kg per year. This is equal to 266 one-way trips during a 25 year period between Gothenburg and Stockholm with a mid-sized car.

    Conclusions to be drawn from the report are that it would not be economically sustainable to construct a self-sufficient house. Since the house is not connected to the district electricity, it cannot sell the surplus electricity during the summer months. However, further studies could be done to determine the opportunities for the house to be fitted with a charging station for electric cars. In this way the house would be able to provide the intrinsic means of transport that does not give any effect on the climate. That could also save the cost of other fuels for transportation.

  • 104.
    Andersson, Rikard
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Berglund, André
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Förbättra lågenergihusens materialval ur ett hållbart perspektiv: En studie hur man kan förbättra valet av isoleringsmaterial till vägg och tak samt material till grundkonstruktionen2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 105.
    Andersson, Roger
    Karlstad University, Faculty of Technology and Science.
    Teaching and learning geometrical optics with computer assisted instruction: changing conceptions about vision, image and ray2007Report (Other academic)
    Abstract [en]

    The information and communication technology, ICT, is opening new possibilities for the educational arena. Previous research shows that achieving positive educational outcomes requires more than simply providing access to computer hardware and software. How does this new technology affect the teaching and learning of physics? This thesis focuses on the field of geometrical optics. It reports two studies, both in Swedish upper secondary school. Important for the use of the ICT in physics education is the teaching strategy for using the new technology. The first study investigates with a questionnaire, how 37 teachers in a region of Sweden use computers in physics education and what intentions they follow while doing so. The results of this study show that teachers’ intentions for using ICT in their physics teaching were to increase students' interest for physics, to increase their motivation, to achieve variation in teaching, and to improve visualization and explanation of the phenomena of physics. The second study investigates students’ conceptual change in geometrical optics during a teaching sequence with computer-assisted instruction. For this purpose we choose the computer software "Constructing Physics Understanding (CPU)", which was developed with a base in research on students conceptions in optics. The thesis presents the teaching sequence developed together with the teacher. The study is based on a constructivist view of learning. The concepts analysed in this study were vision, image, ray and image formation. A first result of this study is a category system for conceptions around these concepts, found among the students. With these categories we found that students even at this level, of upper secondary school, have constructed well-known alternative conceptions before teaching, e.g. about a holistic conception of image. The results show also some learning progress: some alternative conceptions vanish, in some cases the physics conceptions are more often constructed after teaching. The students and the teacher also report that the CPU program gave new and useful opportunities to model multiple rays and to model vision.

  • 106. Andersson, S.
    et al.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Dissociation of Physisorbed H_ $$2$$ through Low-Energy Electron Scattering Resonances2010In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 104, p. 216101-216105Article in journal (Refereed)
    Abstract [en]

    Electron induced dissociation of physisorbed H2, HD, and D2 proceeds, as we observe in electron energy-loss measurements of the resulting atomic species, with a high quantum efficiency via the 2Σg+ core excited electron scattering resonances. We find that the predominant decay of the temporary H2- state to the neutral excited 3Σu+ parent state, which is intramolecularly antibonding, provides a sufficiently long-lived channel for dissociation to occur with high probability, even in the proximity of a metal surface.

  • 107.
    Andersson, S.
    et al.
    Department of Physics, Göteborg University.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Electron-Induced Desorption of Physisorbed H_ $$2$$ via Resonance Vibrational Excitation2009In: Physical review letters, ISSN 0031-9007, Vol. 102, no Issue 15, p. 156104-Article in journal (Refereed)
    Abstract [en]

    We show by electron energy-loss measurements that desorption of physisorbed H2 and D2 induced by low-energy electrons takes place with large cross sections, predominantly via resonance excitation of the molecule-surface vibrational mode. The observed H2, D2 cross-section ratio supports a picture where rotation-translation conversion of the resonance excited j=0→2 rotational transition contributes to the desorption of H2, while this channel is energetically closed for D2

  • 108.
    Andersson, Staffan
    et al.
    Karlstad University, Faculty of Technology and Science.
    Jansson, Mikael
    Karlstad University, Faculty of Technology and Science.
    Framstam till timmerlastbil2008Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    The work is done for the company Höglunds flak in Säffle and aims to develop a new front wall to a timber truck.

    A front wall is what protects the cabin from the logs in case of a collision. The front wall is also used while loading the truck as a loading fixture to beat the logs against.

    The requirements for the front wall from the company are:

    • Easier construction

    • The same deformation at impact testing, surface testing and bending load as the original.

    • Cheaper or the same price as the previous model

    • Withstand the standardization SS 2563, SS 2564

    • Be attractive to the customer

    • Customizable height

    • If possible, get as much production as possible to the own workshop

    The work was divided into two parts where one is to make the plate and how to make it rigid. The second is the beams which are going to keep up the plate and takes the greater part of the impact force.

    Two concepts on the front wall plate, both is of the same material 6082-T6.

    Bending concept.

    The concept consists of an aluminium plate which is bended to an L-profile around the edges to rigid up the plate.

    Square concept.

    This concept consists of a square tube in aluminium which is riveted firmly against the plate.

    Three concepts on the beams. All three are estimated to be in the same material Domex 650

    JL-profile

    Is a profile that is easy to manufacture by bending and is easy to mount on both the plate and in the frame beams.

    I-profile

    The I-beam is made with a larger flange to the plate in order to facilitate the attachment and a small flange on the other side to reduce weight. However, because this is not an original beam it will be manufactured through extrusion.

    W-profile

    W-profile is going to be extruded and is also easy to attach to the plate. It has been developed with the idea of a T-beam which then is stated up with two webs.

    Of the two plate concepts it was the Square concept which was best suited one. The bending concept was not chosen because the material of the plate was for brittle and couldn’t be bent as much as wanted.

    The analysis of the plate was made according to the standard SS2563, SS 2564 with a pressure of a certain distance from the base.

    The FEM analysis at the plate shows that there is no residual deformation, which is the same as the original plate. The square pipe has a lower weight with 19 kg which is 55% lighter compared with the circular pipe profile.

    The profile is able to take up 0,6 kJ more than the Z-profile and 23kg and 23% lighter

  • 109.
    Andersson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Analysis of welding in comparable steel grades: Influence of steel grade on the welding process2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis is written to examine the influence of different low carbon steel sheet materials on the GMAW welding process. During welding the properties of the base material influence the productivity of the welding process. The purpose of this thesis is to examine how the choice of material and welding speed affect the welding process and the productivity.

    A literature survey was performed to describe the welding technique and the differences in manufacturing for the sheet materials as well as the effect of alloying and welding on the sheet material. Defects in the weld and methods used to determine them are explained. Test pieces of the different sheet materials were welded with the GMAW process and examined.

    The result shows that there is a variation in the welding process regarding weld penetration. Measurements also show that welding speed and gap have little influence on the hardness of the weld and heat-affected zone and that the S355MC is more likely to suffer from a narrower toe transition radius than S355NL and S355MC Si. This and the higher area in the Y2 region for the S355MC could indicate a stronger inward flow in the weld pool during welding possibly a result of surface active agents such as oxygen and sulphur.

  • 110.
    Andersson, Stefan
    et al.
    Karlstad University, Faculty of Technology and Science.
    Johansson, Andreas
    Karlstad University, Faculty of Technology and Science.
    Tillämpning av effektstabilisering i PLC2008Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of the degree project is to make a digital realization of a stabilizer for oscillations in the active power from a hydropower synchronous generator, connected to a power network.

    The implementation is supposed to be done in a PLC which already handles part of the excitation system.

    The power stabilization is achieved by sending a counteracting reference signal to the excitation system which controls the generator’s output power. This counteracting signal can be achieved in several ways.

    Two existing models, standardized by IEEE, for power system stabilizing will be examined, PSS1A and PSS2B.

    A Simulink-model of a distribution net with a generator is constructed to test the stabilizers.

    To perform a digital implementation a discrete transformation of one continuous model is done. This discrete model is also tested to verify the function in comparison to the continuous one.

    The discrete model is reorganized in a form possible to implement in the PLC.

    Comparison between the simulated and the implemented model is made by measurement.

  • 111.
    Andersson, Viktor
    Karlstad University, Faculty of Technology and Science.
    Specialemballage för mellanvägg: Ett ergonomiskt emballage2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete på 22.5 högskolepoäng har utförts av student Viktor Andersson vid Karlstads universitet under vårterminen 2012. Examensarbetet ingår kursen Examensarbete för högskoleingenjörsexamen i innovationsteknik och design (MSGC12 -vt 2012) och hör till programstrukturen för innovations och designingenjörsprogrammet.

    Volvo Construction Equipment har haft problem med emballaget för artikeln mellanvägg, där av det givna uppdraget.

    Problemen med emballaget är att det har förekommit lackskador på artikeln samt att det är oergonomisk hantering av emballaget. En ny mellanvägg skall snart introduceras och det medför att emballaget idag blir ännu mer oergonomiskt.

    För att undersöka vilka problem som emballaget har en stor research gjorts, som innefattar intervjuer, observationer och litteraturstudier. Underleverantörer och mekaniska verkstäder har kontaktas för att ge sina synpunkter på lösningar och ge ungefärliga prisuppgifter på ett eventuellt nytt kommande specialemballage.

    Efter en grundlig research följdes idégenerering. För att på så sätt få fram en rad kreativa idéer. Idégenerering ledde fram till sex stycken koncept. Utvärdering av koncepten gjordes i två delar, först med matriser och sedan genom diskussioner med flera kunniga personer inom olika områden. Där efter kunde ett konceptval göras. Konceptet som valdes vidareutvecklades med skissmodeller och ritades sedan upp i CAD för att visualisera konceptet i olika lägen.

    Resultatet av detta projekt blev ett ergonomiskt emballage som gör att användaren inte utsätts för någon tung belastning vid användandet av emballaget. Resultatet redovisades med hjälp av en 3D-modell av förslaget, tillverkningsritningar, materialval samt en rapport.

  • 112.
    Andreas, Svensson
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Nabrink, Robin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    GNSS-Styrning: Information för platschefer2013Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 113.
    Anselmo, Ana Sofia
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    The morphology of polyfluorene: fullerene blend films for photovoltaic applications2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Polymer photovoltaic systems whose photoactive layer is a blend of a semiconducting polymer with a fullerene derivative in a bulk heterojunction configuration are amongst the most successful organic photovoltaic devices nowadays. The three-dimensional organization in these layers (the morphology) plays a crucial role in the performance of the devices. Detailed characterization of this organization at the nanoscale would provide valuable information for improving future material and architectural design and for device optimization.

    In this thesis, the results of morphology studies of blends of several polyfluorene copolymers (APFOs) blended with a fullerene derivative are presented. Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy was combined with dynamic Secondary Ion Mass Spectrometry (dSIMS) for surface and in-depth characterization of the blend films. NEXAFS was performed using two different electron detection methods, partial (PEY) and total (TEY) electron yield, which provide information from different depth regimes. Quantitative compositional information was obtained by fitting the spectra of the blend films with a linear combination of the spectra of films of the pure components. In blends of APFO3 with PCBM in two different blend ratios (1:1 and 1:4 of polymer:fullerene) NEXAFS data show the existence of compositional gradients in the vertical direction for both blend ratios, with clear polymer enrichment of the free surface. A series of APFOs with systematic changes in the side-chains was studied and it was shown that those small modifications can affect polymer:fullerene interaction and induce vertical phase separation. Polymer-enrichment of the free surface was clearly identified, in accordance with surface energy minimization mechanisms, and a compositional gradient was revealed already in the first few nanometers of the surface of the blend films. dSIMS showed that this vertical phase separation propagates throughout the film. It was possible to determine that as the polar character of the polymer increases, and thus the polymer:fullerene miscibility is improved, the tendency for vertical phase separation becomes stronger.

  • 114.
    Anselmo, Ana Sofia
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Dzwilewski, Andrzej
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Rysz, Jakub
    M. Smoluchowski Insitute of Physics, Jagiellonian University, Reymonta 4, Krakow 30–059, Poland.
    Bernasik, Andrzej
    Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, Krakow 30–059, Poland.
    Budkowski, Andrzej
    M. Smoluchowski Insitute of Physics, Jagiellonian University, Reymonta 4, Krakow 30–059, Poland.
    Andersson, Mats R.
    Department of Chemical and Biological Engineering, Chalmers University of Technology.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Moons, Ellen
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Characterisation of vertical phase separation in polymer: fullerene blend films for photovoltaics by dSIMS and NEXAFS2011In: E-MRS 2011 Spring Meeting: Bilateral Energy Conference, Malden, MA: John Wiley & Sons, 2011, p. 62-63Conference paper (Refereed)
    Abstract [en]

    Morphological control and characterization of blend films is key in the development of viable polymer solar cells. Spontaneous formation of vertical compositional gradients during solution processing has been shown for polyfluorene:PCBM blends and rationalized with thermodynamic and kinetic models of nucleation and spinodal decomposition.[1, 2] The extent of vertical stratification is affected by polymer side-chain modification aimed at controlling polymer:fullerene miscibility.[3] Here we present high-resolution film morphology results for several polymer:fullerene systems as obtained from near-edge X-ray fine structure spectroscopy (NEXAFS) in partial and in total electron yield modes. Blend films were found to be polymer- enriched at the surface. Dynamic secondary ion mass spectrometry (dSIMS) and NEXAFS give compositional information at different depths, resulting in a more complete picture of the film morphology.

     

  • 115.
    Anselmo, Ana Sofia
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Dzwilewski, Andrzej
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Rysz, Jakub
    M. Smoluchowski Insitute of Physics, Jagiellonian University, Reymonta 4, Krakow 30–059, Poland.
    Budkowski, Andrzej
    M. Smoluchowski Insitute of Physics, Jagiellonian University, Reymonta 4, Krakow 30–059, Poland.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Moons, Ellen
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Polymer solar cells: Visualizing vertical phase separation in solution-processed films of polymer fullerene blends2012In: Proceedings of the 5th International Symposium Technologies for Polymer Electronics - TPE 12 / [ed] Hans-Klaus Roth, Klaus Heinemann, Ilmenau, Germany: Universitätsverlag Ilmenau , 2012, p. 125-128Conference paper (Refereed)
  • 116.
    Anselmo, Ana Sofia
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Dzwilewski, Andrzej
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Moons, Ellen
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Molecular Orientation and Composition at the Surface of Spin-Coated Polyfluorene:Fullerene Blend Films2013In: Journal of Polymer Science Part B: Polymer Physics, ISSN 0887-6266, E-ISSN 1099-0488, Vol. 51, no 3, p. 176-182Article in journal (Refereed)
    Abstract [en]

    The surface composition in spin-coated films of polyfluorene:fullerene blends was determined quantitatively by near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. By comparing partial and total electron yield spectra, we found vertical compositional differences in the surface region. Furthermore, the orientation of the polymer chains was investigated by variable-angle NEXAFS. Blend films of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole] with [6,6]-phenyl-C61-butyric acid methyl ester in two different blend ratios were studied. Results showed polymer enrichment of the surfaces for films with a polymer:fullerene weight ratio of 20:80 and of 50:50, spin-coated from both chlorobenzene and chloroform solutions. The angular dependence of the NEXAFS spectra of the pure polymer films showed a preferential plane-on orientation, which was slightly stronger in the subsurface region than at the surface. In blend films, this orientational preference was less pronounced and the difference between surface and subsurface vanished

  • 117.
    Anselmo, Ana Sofia
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Dzwilewski, Andrzej
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Moons, Ellen
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Photodegradation of the electronic structure of PCBM and C60 films in air2016In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 652, p. 220-224Article in journal (Refereed)
    Abstract [en]

    Fullerenes are common electron acceptors in organic solar cells. Here the photostability in air of the electronic structures of spin-coated PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) and evaporated C60 films are studied using ultraviolet photoelectron spectroscopy (UPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. After exposing these materials in air to simulated sunlight, the filled and empty molecular orbitals are strongly altered, indicating that the conjugated π-system of the C60-cage has degraded. Even a few minutes in normal lab light induces changes. These results stress the importance of protecting fullerene-based films from light and air during processing, operation, and storage.

  • 118.
    Anselmo, Ana Sofia
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Dzwilewski, Andrzej
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Wang, Ergang
    Department of Chemical and Biological Engineering, Chalmers University of Technology.
    Andersson, Mats R.
    Department of Chemical and Biological Engineering, Chalmers University of Technology.
    Hörmann, Ulrich
    Institute of Physics, Augsburg University.
    Opitz, Andreas
    Institute of Physics, Augsburg University.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Moons, Ellen
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Surface Organization in Thin-Films of Conjugated Polymers for Organic Photovoltaics2011Conference paper (Other academic)
  • 119.
    Anselmo, Ana Sofia
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Dzwilewski, Andrzej
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Wang, Ergang
    Chalmers University of Technology.
    Andersson, Mats R.
    Chalmers University of Technology.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Moons, Ellen
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Molecular orientation and composition at the surface of APFO3:PCBM blend films2012In: Hybrid and Organics Photovoltaics Conference: Uppsala, Sweden, 2012 / [ed] Anders Hagfeldt, SEFIN, Castelló (Spain), 2012, p. 278-Conference paper (Refereed)
  • 120.
    Anselmo, Ana Sofia
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Lindgren, Lars
    Department of Chemical and Biological Engineering, Chalmers University of Technology.
    Rysz, Jakub
    Institute of Physics, Jagiellonian University, Poland.
    Bernasik, Andrzej
    Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Poland.
    Budkowski, Andrzej
    Institute of Physics, Jagiellonian University, Poland.
    Andersson, Mats R.
    Department of Chemical and Biological Engineering, Chalmers University of Technology.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Moons, Ellen
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Tuning the Vertical Phase Separation in Polyfluorene:Fullerene Blend Films by Polymer Functionalization2011In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 23, no 9, p. 2295-2302Article in journal (Refereed)
    Abstract [en]

    Achieving control over the nanomorphology of blend films of the fullerene derivative [6,6]-phenyl C61-butyric acid methyl ester, PCBM, with light-absorbing conjugated polymers is an important challenge in the development of efficient solution-processed photovoltaics. Here, three new polyfluorene copolymers are presented, tailored for enhanced miscibility with the fullerene through the introduction of polymer segments with modified side chains, which enhance the polymer’s polar character. The composition of the spincoated polymer:PCBM films is analyzed with dynamic secondary ion mass spectrometry (dSIMS). The dSIMS depth profiles demonstrate compositional variations perpendicular to the surface plane, as a result of vertical phase separation, directed by the substrate. These variations propagate to a higher degree through the film for the polymers with a larger fraction of modified side chains. The surface composition of the films is studied by Near-edge X-ray absorption fine structure spectroscopy (NEXAFS). Quantitative analysis of the NEXAFS spectra through a linear combination fit with the spectra of the pure components yields the surface composition. The resulting blend ratios reveal polymer-enrichment of the film surface for all three blends, which also becomes stronger as the polar character of the polymer increases. Comparison of the NEXAFS spectra collected with two different sampling depths shows that the vertical composition gradient builds up already in the first nanometers underneath the surface of the films. The results obtained with this new series of polymers shed light on the onset of formation of lamellar structures in thin polymer:PCBM films prepared from highly volatile solvents

  • 121.
    Anselmo, Ana Sofia
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Lindgren, Lars
    Department of Chemical and Biological Engineering, Chalmers University of Technology.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Hörmann, Ulrich
    Institute of Physics, University of Augsburg.
    Brütting, Wolfgang
    Institute of Physics, University of Augsburg.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Andersson, Mats R.
    Department of Chemical and Biological Engineering, Chalmers University of Technology.
    Opitz, Andreas
    Institute of Physics, Humboldt University Berlin.
    Moons, Ellen
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Polyfluorene copolymers with functionalized side chains: Opto-electronic properties and solar cell performance2012Manuscript (preprint) (Other academic)
  • 122.
    Anselmo, Ana Sofia
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Moons, Ellen
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Morphology of Thin-Films of Polyfluorene: Fullerene Blends2008In: 1st Portuguese Young Chemists Meeting, PYCheM: Abstracts, 2008, p. 36-36Conference paper (Refereed)
  • 123. Ariño, Ingrid
    et al.
    Kleist, Ulf
    Barros, Gustavo Gil
    Karlstad University, Faculty of Technology and Science.
    Johansson, Per-Åke
    Rigdahl, Mikael
    Surface Texture Characterization of Injection-Molded Pigmented Plastics2004In: Polymer Engineering and Science, ISSN 0032-3888, Vol. 44, no 9, p. 1615-1626Article in journal (Refereed)
  • 124.
    Arntsson, Timmy
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Elnätet och dess anpassning för elektriska fordon: En studie av hur ett lokalnät påverkas av ett ökat antal elektriska fordon2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The availability of non-renewable fuels is decreasing and therefore the prices of both petrol and diesel has increased in recent years. As a result more and more chooses to invest in cars powered by alternative fuels and the focus has long been on electric vehicles. However, this means greater weight on utility companies around the world which now have to adjust to a higher demand. The purpose of this study is to investigate how a local network are affected by electric car chargers and be able to describe the degree to which a low-voltage can be loaded with electric car chargers for commercial and private use, in order to provide recommendations for the future dimension of the local networks. Few studies have been conducted regarding electric cars from a network and supply perspective, but have instead been focused on energy storage in the actual vehicle. Therefore, this study has been processed with an electricity grid perspective.

    The intent of the study has been answered by both a measurement and several simulations. The study is based on Karlstad’s local electrical network and the commercial charging station Tesla in Våxnäs, Karlstad. The parameters of power quality for which this study has taken into account are load of the transformers, load loss, power factor, efficiency, voltage levels, voltage drop and asymmetry.

    The methodological conditions have led to a result that can be used as a basis for an expansion of electric cars, big or small. The measurement was of great support to get an overall view of how the characteristics of a charging session appeared and how the quality parameters were affected during high as well as low power charging. Limitations within the simulation program have led to the calculations to carry out in a more extreme scenario when it comes to the load. A result since the simulation time for constant power was minimum one hour.

    Based on the measurement and simulations of the charging station for commercial use is dimensioned well to cope with the current use of electric vehicle charging. More municipalities should follow Karlstad’s example for the development of commercial charging stations. In the countryside great problems occurred, especially with voltage drop at an increased use of home chargers for electric cars. The same problems emerged in the city part of the network. The study also showed serious problems with asymmetry in the city. The report concluded, therefore, several recommendations for the future dimension of local networks for private homes, for example that the local network should be divided into multiple trails.

  • 125.
    Arvidsson, Daniel
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Estimation of the possible waste reduction by the implementation of SODIS: A numerical-, experimental- and social study executed in Ghana2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Lack of safe drinking water is one of the biggest humanitarian problems in the world today. Over one billion people in developing countries have no access to good quality drinking water, and subsequently, diarrhoea caused by unclean water leads to 1.8 million deaths of children under the age of five. That corresponds to 90 per cent of all deaths among children in that age group. However, by improving water and sanitation management, one tenth of all worldwide cases of disease can be prevented. In relation to this, the United Nations has launched the seventh millennium goal, which is to half the proportion of people lacking access to safe drinking water by year 2015 (compared with the proportion of year 2000). Therefore, it is important to both improve and develop water treatment techniques in order to achieve a sustainable development, especially in the third world.

     

    Kofi Ansah and Edumafa are two villages on the Ghanaian countryside. Here, as in the rest of Ghana, it is common to drink water from throwaway plastic containers. This is because the water quality is poor in the stationary water sources such as tanks and wells etc. The plastic containers contribute to a big waste problem and it´s therefore desirable to improve the water quality in stationary water sources in order to reduce the waste problem that now is occurring.

     

    Solar Disinfection, or SODIS, is a water treatment technique that is based on solar radiation. Water containers (usually PET bottles) are filled with water and then exposed to the sun for about six hours. The germicidal effect can be derived to thermal heating in combination with the sun’s ultraviolet radiation. The technique is suitable in the third world since the treatment procedure is both simple and inexpensive. The purpose of this study was to estimate the possible waste reduction regarding the small plastic containers by the implementation of SODIS as a water treatment technique, and evaluate if SODIS is an adequate way to improve the quality of water collected from stationary water distribution systems in Ghana.

     

    The study has shown that SODIS is an adequate method for producing low health risk water at a household level in Ghana. A solar exposure of six hours is enough to reach a safe bacterial content within the treated water. It is also clear that SODIS could reduce the present waste problem regarding the throwaway plastic containers by more than 1600 plastic bags per person and year, and that the Ghanaians attitude to start performing SODIS is positive.

     

    Further work should be aimed at implementing SODIS as a water treatment technique by teaching the Ghanaian people, especially in the rural areas, the importance of water and sanitation issues. The implementation of SODIS is a long term project that cannot be accomplished singlehandedly. It can be achieved by instructing certain people in the villages as to how the procedure is done. For this to be effective, these individuals should preferably be well educated and speak both English and the local language. These people can in turn educate and instruct the other villagers in how SODIS is executed and by doing so complete and secure a sustainable use of the technique.

  • 126.
    Arvidsson, Johan
    et al.
    Karlstad University, Faculty of Technology and Science.
    Leidefeldt, Marcus
    Karlstad University, Faculty of Technology and Science.
    Unosson, Tobias
    Karlstad University, Faculty of Technology and Science.
    Ergonomic Cabin Access: Utveckling av in- och ursteg till hög lastbilshytt2006Independent thesis Basic level (professional degree), 20 points / 30 hpStudent thesis
    Abstract [en]

    This degree project was performed by students of the Innovation and design engineering programme on Karlstad University, Sweden. Group members have been Johan Arvidsson, Marcus Leidefeldt and Tobias Unosson. The degree project consisted of 20 weeks of work of which 5 was an individual study in literature. The project carried out during the spring of 2006.

    Assigner for the project was Hedenberg Advanced Vehicle Design, HAVD, who is a development company serving the vehicle industry and specializing in interior parts and trim. Contacts were Björn Hedenberg and Ingemar Carlson, HAVD. Examiner at Karlstad University was Lennart Wihk. The project was also collaboration together with VOLVO Truck Car Corp in Gothenburg.

    The task the students were given was to improve and develop a new solution for truck drivers, getting in and out of high trucks. A goal with the project was to build a functioning prototype on a VOLVO truck to be shown at the exhibit for degree projects in Karlstad, May 2006.

    In this project the students participated in a project management course given by HAVD in their facilities. The group toke part of a new development method originated from the vehicle industry. This method was used as a frame for the entire project and consisted of three phases, the idea phase, research phase and the realization phase. Between each phase of the project there was a point called a gate, in which important decisions were maid in the group together with HAVD.

    The project resulted in a mechanical lift, mounted onto the side of the truck transporting the driver safely up and down. The solution was named ECA, Ergonomic Cabin Access. Drawings for the concept and its mounting were completed along with an economic calculation. The final result is developed with focus on the driver ergonomics with a sensible construction using available components. The core in the construction is the so called linear motion drive. This device transforms a rotating force into a linear motion. The concept was adapted to fit a VOLVO truck by replacing the trucks previous three footsteps.

    The final concept was presented at HAVD and Karlstad University at the exhibit for degree projects, 30 May 2006. The concept could not however be built into a prototype due to financial reasons. The degree project ECA resulted in drawings, renderings, animations and this academic report.

  • 127.
    Arvidsson, Linda
    Karlstad University, Faculty of Technology and Science.
    Ipad som pedagogiskt verktyg i förskolan: En studie om pedagogers och förskolebarns syn på ipad i verksamheten2013Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 128.
    Ashri, Nadia Y.
    et al.
    Najd Consulting Hosp, Riyadh, Saudi Arabia..
    Abdel-Rehim, Mohamed
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. AstraZeneca R&D Sodertalje, Clin Pharmacol, SE-15185 Sodertalje, Sweden.;AstraZeneca R&D Sodertalje, DMPK, SE-15185 Sodertalje, Sweden.;Karlstad Univ, Dept Chem & Biomed Sci, SE-65188 Karlstad, Sweden.;Stockholm Univ, Dept Analyt Chem, SE-10691 Stockholm, Sweden..
    Sample treatment based on extraction techniques in biological matrices2011In: Bioanalysis, ISSN 1757-6180, E-ISSN 1757-6199, Vol. 3, no 17, p. 2003-2018Article, review/survey (Refereed)
    Abstract [en]

    The importance of sample preparation methods as the first stage in bioanalysis is described. In this article, the sample preparation concept and strategies will be discussed, along with the requirements for good sample preparation. The most widely used sample preparation methods in the pharmaceutical industry are presented; for example, the need for same-day rotation of results from large numbers of biological samples in pharmaceutical industry makes high throughput bioanalysis more essential. In this article, high-throughput sample preparation techniques are presented; examples are given of the extraction and concentration of analytes from biological matrices, including protein precipitation, solid-phase extraction, liquid-liquid extraction and microextraction-related techniques. Finally, the potential role of selective extraction methods, including molecular imprinted phases, is considered.

  • 129.
    Asp, Daniel
    Karlstad University, Faculty of Technology and Science.
    Kvalitetsbristkostnader i monteringshallen: Vad beror de på, hur stora är de och vad går det att göra åt dem?2006Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [sv]

    Sammanfattning

    Monteringshallen hos Metso Paper Karlstad är beroende av många utomstående funktioner och processer. De som jobbar med montering och utcheckning måste koordinera sina arbeten med tillverkningen, underleverantörer, inköp, konstruktion och skeppning.

    Alla är medvetna om att det finns problem i monteringshallen och att det måste det göras något för att komma till rätta med dem. Men vilka orsakerna är till problemen finns det olika uppfattningar om. En del upplever det också som att problemen återkommer gång på gång. Få försök har gjorts för att på metodiskt sätt få en gemensam syn på problematiken eller ta fram fakta som kan ligga till grund för beslut om förbättringsområden. Dessutom finns en attityd om att kvalitetsarbete mest tar tid. Problemen anses inte härröra från montaget utan de får helt enkelt finna sig att vara de som städar upp efter andra.

    Syftet med detta examensarbete har varit att svara på frågeställningar om problemens orsaker, dess kostnadsstorlekar och vilka åtgärder som kan vara lämpliga för att minska kvalitetsbristkostnaderna i monteringshallen. Det övergripande målet har varit monteringshallens utveckling av kvalitetsarbetet. Rapporten är baserad på de anställdas erfarenheter som framkommit vid intervjuer. Teorin är vald med fokus på de olika delar som krävs för långsiktigt och kontinuerligt kvalitetsarbete.

    Intervjuerna visar att medvetenheten om sin egen del i problem och problemlösning är låg. De betraktar sig själva som om de inte har del i problemen. Detta är mindre bra eftersom det finns många beroenden till andra funktioner. Dessutom behandlas det många varianter av maskiner vilket än mer ökar behovet av väl fungerande processer. Därför är den nuvarande attityden och kvalitetstänkandet ett stort hinder mot nödvändigt förbättringsarbete. Orsakerna till omarbetningar lagras inte vilket försvårar möjligheterna att på ett effektivt sätt finna lösningar på problemen.

    Rapportens resultat är en genomgång av de nödvändiga byggstenar som krävs för att långsiktigt kunna bedriva framgångsrikt kvalitetsarbete. Det rekommenderas att personer med chefsbefattning tar in de synpunkter som har påpekats och gör en prioritering av det som behöver åtgärdas. Nedanför listas förslag på åtgärder för ett förbättrat kvalitetsarbete i monteringshallen.

    1. Tillsätt en resurs som jobbar aktivt med förbättrings- och kvalitetsfrågor (förbättringssamordnare/ledare).

    2. Börja med pilotgrupp/avdelning som får utbildning i kvalitetsmetoder och verktyg parallellt med förbättringsarbetet.

    3. Informera och utbilda personalen i grunderna inom kvalitet för att få ett gemensamt språk

    4. Våga genomföra förändringar.

    5. Börja med att åtgärda saker som ger tydliga förbättringar med hjälp av 5S

    6. Förbättra Baan-systemet så att det går att spara felorsaker

    7. Kartläggning och förbättring av processerna

  • 130.
    Augustson, Erik
    et al.
    Karlstad University, Faculty of Technology and Science.
    Stanser, Oscar
    Karlstad University, Faculty of Technology and Science.
    Projektutveckling av kvarteret Ärtan: Marknadsanalys2009Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

     

    Skanska Hus Väst is planning to construct condominiums in an area called Ärtan which lies in Karlstad, in the city district of Romstad. To be able to construct condominiums in this area a market analysis is needed. The market analysis describes the most appropriate type of residence to construct depending on ground conditions, public demand, the surrounding buildings and environment, the pattern in which the inhabitants move in the rural- and in the city district and how much the customer is willing to pay for a condominium on Ärtan. This means that relevant statistics of income, employment, prices on equal objects and more is needed to forecast the housing- and property market.

     

    The first part in the project development of Ärtan is to make a market analysis. The market analysis includes the city analysis, the object analysis and the business intelligence, figure 2.  

    The business intelligence is not included because the report is demarcated to the city- and object analysis only. The city- and object analysis will result in the determination of a suitable target group and how much the customer will be willing to pay for a condominium in Ärtan.  The purpose of this study is to determine these two and also decide the methods most appropriate for analyzing and determining the will of payment for the project.

     

    Business intelligence

    MARKET ANALYSIS

    City analysis

    Object analysis

    A short description of the city

    Business sector and employment

    Housing - and property market

    Population

    Supply and demand

      The state of the Property market

    A short description of the object

    Location analysis

    Equal objects

    Incomes and profitability

    Figure 2. Layout of the market analysis.

     

    The methods used for analyzing and making a conclusion in the report are:

    • Tobins Q
    • Business sector specialization quota
    • Regression analysis
    • Multiple Regression analysis
    • The method of location and price (Ortprismetoden)
    • Demand with the help of elasticity's.

     

    With these methods and with a great amount of collected data we have drawn the conclusion that the conditions for constructing condominiums in Ärtan are not optimal but still profitable. We have tried to make this judgment as objective as possible and we have looked at all the advantages and disadvantages of the area. Karlstad's business sector and employment have increased during the last years and are displaying good conditions to withstand these troubling financial times.

    We found good conditions to invest in the real estate market in Romstad, due to the lack of condominiums in the area and due to a higher level of incomes compared to the rest of the inhabitants of Karlstad.

               

    After the traces from the financial crises we assess that the will of payment on condominiums on Ärtan should be about 22 000 Swedish kronor/m2 (living area) in the interval of 20 500 - 23 000 Swedish kronor/m2 (living area). Suitable target groups for the product are people which have a good and firm will of payment and are in their thirties or forties. A good thing to do is also to adjust parts of the condominiums for older inhabitants. Our opinion is that a mix of younger and older people creates charm, comfort and a sense of safety in the neighborhood which is needed to get the area more attractive on the market.

     

    All the methods that were used in this analysis showed similar results which led us to the conclusion that all of the methods used are suitable for this assignment. However, the combination of the multiple regression analysis and the brokers' opinions is the most suitable one for the assignment because the combination can be executed easy, swift and true.

  • 131. Avizzano, C.A.
    et al.
    Raspolli, M.
    Solis, Jorge
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Marcheshi, S.
    Bergamasco, M.
    Haptic Desktop for Office Automation and Assisted Design2005In: Proceedings of the 2005 IEEE International Conference on Robotics and Automation, IEEE conference proceedings, 2005, p. 4086-4091Conference paper (Refereed)
    Abstract [en]

    The present paper describes the conceptual and technical design of a new multimodal device named Haptic Desktop System (HDS). Haptic Desktop System is an integrated system, which merges haptic functionalities, and VDT systems into one. Specific care has been given to HDS design for enhancing and improving human-computer interaction from the following points of view: esthetical, ergonomic and functional. In order to improve the quality of the interaction, the HDS fully integrates proprioceptive, visual, audio and haptic functionalities, into a desk while minimizing the visual interference of the physical components. In the proposed approach classic input devices (i.e. keyboard and mouse) have been replaced by new features integrated within audio and haptic. Such features allow commanding and rendering natural force stimuli in such a way that they are completely coherent and co-located with respect to the visual information. The new features of the HDS are designed for reducing considerably the mental load required to the users during interaction operations. In the present paper the design guidelines and the achieved results are reported

  • 132. Avizzano, C.A.
    et al.
    Solis, Jorge
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Frisoli, A.
    Bergamasco, M.
    Motor Learning Skill Experiments Using Haptic Interface Capabilities2002In: 11th IEEE International Workshop on Robot and Human Interactive Communication. Proceedings., IEEE , 2002, p. 198-203Conference paper (Refereed)
    Abstract [en]

    This paper investigated the influence that proportional feedback programmed into haptic interface (HI) can have in the development of motor skills. The haptic interface design, adapted to the task to be performed, plays a key role inside motor learning processes as the kinesthetic and proprioceptive are the information pathway in the perception of incoming stimuli. Subjects learned to draw a shape using two kinds of training methods: visual, visual and haptic. The error position distance was measured and a statistical analysis was done in order to identify user's motion improvement when training trials were alternated with practice trials. In order to constraint the user to draw a predefined path, a control law is presented.

  • 133.
    Awan, Muhammad Ashraf Ali
    Karlstad University, Faculty of Technology and Science. ISEA-RWTH.
    Remaining useful life prediction of lithium-ion batteries using particle filter framework2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A method for the prediction of remaining useful life (RUL) of li-ion battery for battery management system (BMS) is presented in this thesis work. Estimation of State of charge (SOC), state of health (SOH) and RUL are important tasks in BMS. For the prediction of RUL, information of aging parameter is required. Previously, in RUL prediction methods, aging parameter information was based on the battery tests data. For online estimation of RUL, ageing parameter is required and BMS does have a sensor system which could measure the battery ageing parameter online. So estimation techniques are utilized for the estimation of ageing parameters. Previously different methods were used such as Fuzzy logic, artificial neural network (ANN) and Kalman filters. Fuzzy logic and ANN methods are computationally heavy to implement them in BMS of EVs. Kalman filters methods are not very accurate for the estimation of an ageing parameter because batteries are highly nonlinear system and Kalman filters can only capture nonlinearity up to 3rd order Taylor series expression. This thesis work presents an algorithm for the prediction of RUL, which is based on the information of SOH. To predict the behaviour of the battery, Thevenin battery model is selected and internal resistance of the battery is considered as an ageing parameter. Internal resistance changes due to change in temperature. Particle filtering framework is implemented for estimation and is found that unscented particle filter gives better estimation of ageing parameter because it adapts the ageing parameter with respect to temperature change. RUL prediction consists of two steps. In first step, SOC and ageing parameter is estimated and then SOH is calculated from ageing parameter. In second step, RUL is predicted from the information of SOH. Variable load and effect of temperature are also considered for the estimation of ageing parameter. SOH is obtained from the ageing parameter and then a degradation model is developed from the information of SOH. Remaining cycles of the battery are then predicted from this degradation model by using particle filter.

  • 134.
    Axelsson, Mikael
    et al.
    Karlstad University, Faculty of Technology and Science.
    Joelsson, David
    Karlstad University, Faculty of Technology and Science.
    Åkman, Karl
    Karlstad University, Faculty of Technology and Science.
    NEOS Office Workstation 2007: Daifukudesigns, Barcelona2008Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    The project consisted of developing an office workstation specially designed to compete at the Spanish market. The assignment was received from the Daifuku Designs, a design company in Barcelona, Spain. Daifuku Designs are well experienced in various kinds of product and interior design, but has not designed office furniture earlier. The project’s purpose was to introduce the company to the branch of office furniture.

    The research phase consisted in three different parts, a survey concerning office work that was handed out to Swedish and Spanish office workers and cleaning staff, studies of the world leading companies in the branch of office furniture and educational visits at different showrooms and offices.

    The project resulted in a desk that is offering a flexible space dividing system and a unique cord solution. The space dividers can be put anywhere along the desktop and are easily moved by hand. All the cords and cables are hidden in the desk and computers, phones, e.g. can be installed anywhere on the desk. The desk can be used both separately and in big office landscape. Flexibility is a common sales argument and the demand of this kind of flexibility is constantly growing. The trends to hire personnel and to work in temporary project groups are two reasons to the growing demand. The office furniture needs to be able to be used in different ways when the constellation of the project group is changing. It is a big advantage if the same desks can be used for different occasions.

  • 135.
    Axén, Fredrik
    Karlstad University, Faculty of Technology and Science.
    Laborativ matematik: Att variera undervisningen med alternativa metoder2009Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report investigates various ways of diversifying mathematics teaching, especially elaborative mathematics. Primarily it focuses upper secondary school, but the results should have an impact on lower and higher levels as well. From an account of teacher and student views the report provides some concrete suggestions for improvement. The purpose of the report is to investigate alternatives for the traditional ways of teaching. Five teachers known for their experience on alternative teaching methods and on laboratory mathematics have been interviewed.

     

    The result shows that mathematics teaching is uniform and that it needs to be diversified. The report presents a sample of ideas for such teaching. Many teachers are willing to try this type of teaching but hesitate since there are no proofs of positive results or because there is too little time for such methods. A diversified, laboratory teaching seems to contribute good results but this has not been proved.

  • 136.
    Ayedi, Omar
    Karlstad University, Faculty of Technology and Science, Avdelningen för energi-. miljö- och byggteknik.
    Energieffektiv torkning av kläder: en studie av torktumlare med varm- respektive kallvattenanslutning2011Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Tumble dryers and drying cabinets have to a large extent replaced the traditional way of drying clothes outdoors. They are faster, more convenient, require less space and can be operated regardless of weather conditions. This replacement has significantly increased residential energy consumption, due to the fact that tumbles dryers consume large amounts of electrical energy. In the USA 9 % of the households electric energy is consumed when drying clothes. Over 4 million tumble dryers are sold in Europe each year and 20 % of the residential electricity consumption in Sweden is used drying and washing clothes. Tumble dryers are also utilized in the industrial sector, but industrial dryers are not considered in this study.Increasing energy costs contributes to the public’s awareness and desire to cut their energy consumption. The aim of this study is to increase the energy efficiency and drastically reduce electric power use of tumble dryers.There are two main types of tumble dryers available on the market; the open cycle tumble dryer and the closed cycle tumble dryer. The open cycle tumble dryer is often attached to the ventilation system and thereby it evacuates its exhaust air. The closed cycle tumble dryer condenses the water from the air before it recirculates it.To increase the energy efficiency and reduce electric power use of tumble dryers, two separate studies were made. One on a water cooled closed cycle tumble dryer and one on a hot water heated open cycle tumble dryer. Both tumble dryers where rebuild and originated from the same tumble dryer. The tumble dryer that both studies originated from was a conventional air cooled closed cycle tumble dryer. The tumble dryer is made by Asko Cylinda AB.The results reveal that the water cooled closed cycle tumble dryer does not have greater energy efficiency than the conventional air cooled closed cycle tumble dryer. However the drying time was reduced by 37 %.The result also reveals that the hot water heated open cycle tumble dryer cuts the electric consumption by 93 % and improves the energy efficiency by 53 % compared to the conventional air cooled closed cycle tumble dryer. On the other hand the drying time increases by 9 %.

  • 137. Baba, S.
    et al.
    Granath, Håkan
    Karlstad University, Faculty of Technology and Science, Department of Mathematics.
    Genus 2 Curves with Quaternionic Multiplication2008In: Canadian Journal of Mathematics, Vol. 60 (4)Article in journal (Refereed)
    Abstract [en]

    We explicitly construct the canonical rational models of Shimuracurves, both analytically in terms of modular forms andalgebraically in terms of coefficients of genus 2 curves, in thecases of quaternion algebras of discriminant 6 and 10. Thisemulates the classical construction in the elliptic curvecase. We also give families of genus 2 QM curves, whose Jacobiansare the corresponding abelian surfaces on the Shimura curve, andwith coefficients that are modular forms of weight 12. We applythese results to show that our j-functions are supported exactlyat those primes where the genus 2 curve does not admitpotentially good reduction, and construct fields where thispotentially good reduction is attained. Finally, using j, weconstruct the fields of moduli and definition for some moduliproblems associated to the Atkin-Lehner group actions

  • 138. Baba, Srinath
    et al.
    Granath, Håkan
    Karlstad University, Faculty of Technology and Science, Department of Mathematics.
    Primes of superspecial reduction for QM abelian surfaces2008In: Bulletin of the London Mathematical Society, Vol. 40Article in journal (Refereed)
  • 139. Babcock, G.T.
    et al.
    Floris, R.
    Nilsson, Thomas
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Pressler, M. A.
    Varotsis, C.
    Vollenbroek, E.
    Dioxygen activation in enzymic systems and in inorganic models1996In: Inorg. Chim. Acta, 243 , 345-353Article in journal (Refereed)
  • 140. Backfolk, K.
    et al.
    Johansson, Caisa
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Paper Surface Centre.
    Peltonen, J.
    Association between a sodium salt of a linear dodecylbenzene sulphonate and a non-ionic fatty alcohol ethoxylate surfactant during film formation of styrene/butadiene latex2006In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2006, 291 (1-3), 38-44Article in journal (Refereed)
  • 141.
    Backman, Carl
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Lindefelt, Daniel
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Mångfaldens Jakobsberg: En plats för alla2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 142.
    Bajracharya, Quree
    Karlstad University, Faculty of Technology and Science.
    Dynamic Modeling, Monitoring and Control of Energy Storage System2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today there is a great interest on the small scale renewable electricity generation due to the changing economics and the demand for highly sustainable electricity generation. However, renewable energy sources are unreliable and fluctuating which causes variation of power flow. In this situation, there can be server problems such as frequency oscillations, violation of the power line capability jeopardizing the security of the power system. Batteries can be an emerging technology which acts as the fast acting spinning reserve that can balance between the load and generation. Conversely, it very difficult to accurately predict battery performance and the total cost of the investment of storage system by integrating batteries to the renewable system as batteries in this situation have to bear a wide range of the operational conditions . Henceforth, modeling of the battery is extremely important. This master thesis gives the dynamic modeling of the batteries which can replicate the relevant behavior of the battery.

    The proposed methodology is the model based approach where the parameters are determined to develop a suitable model. In this thesis, the battery is modeled as an R-C circuit comprising of elements each of which represents certain battery characteristics. An appropriate model is selected based on the comparative study of the characteristics of experimental output of the battery using model identification. Parameters of the battery are computed in the MATLAB Simulink parameter estimation toolbox using least square estimation .The initial parameter values for the simulink are found with the help of the lab test. Validation results from the two experimental data shows that the model can accurately estimate the battery characteristics with an error of 0.3%.The aforementioned battery model is later used to make an appropriate charge controller.

    The methods used in the thesis performed quite well within the limited tests performed during the experimental works. To use the model online in the future, further investigation is recommended in order to refine the model.

  • 143.
    Baladi, Jibran
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Khan, Naeem ullah
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Analysis and Reporting of the control tests conducted in connection withcommissioning for control systemupgrade at Ringhals 2.2013Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    This master thesis project was carried out at Ringhals AB Unit 2. It is focused on modeling and introducing a new control strategy for control loop 21414V141/131 which is a condensate water system. Existing control strategy of the selected control loop is simple feedback control system with one PID controller. Results of current control strategy were taken into account for improvements in terms o f system stability, valve movements and unwanted transients. Problems found in selected loop were; large variations in process variable, extra movement in valve positions and inefficient opening of valves.Simulation model with similar control strategy and results as of real power plant was createdand validated, as new control strategy can be applied and results can be compared. The main recommendation to improve the control system performance was found through cascade control strategy that could assist the current controller. The recommendation was evaluated by designing and implementing the cascade control strategy on the Dymola simulation model. Simulation results pointed out considerable increase in system performanceaccording to the requirements of Vattenfall AB.

  • 144.
    Baradi, Divyank
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Control strategies and inspection methods for welded part2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Present and future demonstrator designs were used to demonstrate the quality assurance of welds. The NDT methods tested on prototype demonstrator parts are: visual inspection, radius gauges, throat size gauge, liquid-penetrant testing, magnetic particle testing and ultrasonics with pulse echo and phased array. The other methods like eddy current, time of flight diffraction, radiography, impression test, macro test and infrared thermographs are currently being analyzed along with their inspection costs.

     

    The control plans for present and future designs with corresponding present and future NDT methods are suggested to minimize a shift in process.

    • Magnetic particle testing revealed a lack of fusion and cracks for fillet welds, whereas ultrasonic pulse echo and phased array identified an internal lack of fusion, inner pores/slag inclusions on butt welds.
    • Ultrasonic PAUT & TOFD could be used for accurate defect identification and thermography for online identification of lack of penetration, depth of penetration and weld parameters.
  • 145.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Beghello, L
    Magnetic printing for packaging industry: methods and feasibility2006Conference paper (Refereed)
  • 146.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences, Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Larsson, Per-Lennart
    Östlund, Sören
    Hallbäck, Nils
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Karathanasis, Michael
    On material characterization of paper coating materials by microindentation testing2005In: JCT: Journal of Coatings Technology, ISSN 0361-8773, Vol. 2, no 6, p. 463-471Article in journal (Refereed)
    Abstract [en]

    Microindentation as a method for determining important material properties of paper coating materials is studied experimentally and numerically. The bulk of the investigation is concentrated upon the short-lived elastic part of a spherical indentation test, but determination of the failure stress of the coating is also discussed. The results indicate that microindentation can be a powerful tool for material characterization of these materials, but only if careful efforts are made to account for the influence from plasticity as well as from boundary effects

  • 147.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences, Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Larsson, PL
    KTH Stockholm.
    Östlund, S
    Experimental investigation of damage at folding of coated papers2002In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 17, no 1, p. 34-Article in journal (Refereed)
    Abstract [en]

    To achieve a better understanding of the folding properties of coated papers pertinent to the mechanical behaviour, a microscopic investigation was performed. The influence on the damage levels in the coating from such features as delamination, humidity and paper thickness have been studied

  • 148.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Larsson, PL
    Östlund, S
    Numerical investigation of folding of coated papers2005In: Composite StructuresArticle in journal (Refereed)
    Abstract [en]

    Folding of coated paper is examined numerically using the finite element method. Particular emphasis is put on the behaviour of field variables relevant for cracking of the coating layers. In the numerical analysis, the basepaper is modelled as an anisotropic elasticplastic material (both elastic and plastic anisotropy is accounted for) while the constitutive behaviour of the coating layers are approximated by classical (Mises) elastoplasticity. The numerical results suggest, among other things, that particular forms of plastic anisotropy can substantially reduce the maximum strain levels in the coating. It is also shown that delamination buckling, in the present circumstances, will have a very small influence on the strain levels in the coating layer subjected to high tensile loading

  • 149.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Larsson, PL
    Östlund, S
    On dynamic effects at folding of coated papers2005In: Composite StructuresArticle in journal (Refereed)
  • 150.
    Barbier, Christophe
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences, Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Larsson, PL
    KTH Stockholm.
    Östlund, S
    On the effect of high anisotropy at folding of coated papers2007In: Composite structures, ISSN 0263-8223, E-ISSN 1879-1085, Vol. 72, no 3, p. 330-338Article in journal (Refereed)
    Abstract [en]

    A finite element procedure, developed in order to account for the effect of high anisotropy at folding of coated papers, is presented. The anisotropic behaviour (with very low stiffness in the thickness direction) is modelled using stiff structural elements (trusses and beams). The numerical results indicate that high elastic anisotropy leads to lower strain levels at folding than reported in previous analyses where this effect was not accounted for. High plastic anisotropy, on the other hand, will contradict this result

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