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  • 151.
    El-Mobader, Sarah Hassan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Effect of Lap Belt Position on Kinematics & Injuries by using 6YO PIPER child HBM: in Frontal Crash Simulations2018Independent thesis Advanced level (degree of Master (Two Years)), 300 HE creditsStudent thesis
    Abstract [en]

    Traffic accidents are the second leading cause of child fatality among children younger than 15 years of age. In the course of 10 years, the implementation of child restraint systems has decreased child fatality in traffic accidents with 50%, for children younger than 15 years. To gain an understanding of the kinematics and injury mechanisms of children in cars, finite element based human body models, representing higher biofidelity compared to crash test dummies, are developed. An FP7 European project, PIPER, developed a child HBM with an associated framework for scaling, morphing and positioning. The PIPER child HBM is scalable between the ages of 1.5-6YO, with scalable anthropometrics. This makes the PIPER child HBM, a powerful tool for analyzing children in vehicles. 

    There are insufficient analyses conducted with the PIPER child HBM, due to its recent release. The purpose is thus to study the robustness of the HBM and its sensitivity to variation of lap belts by conducting a parametric study. Injury analysis and its sensitivity to lap belt variations were in addition studied in terms of kinematics by the study of submarining, the pelvic interaction with the lap belt, and the study of injuries related to the skull, brain, kidneys and liver.

    A full frontal crash simulation of a 6YO PIPER child HBM, with anthropometrics, covering the 50th percentile, have been investigated. The 6YO PIPER child HBM was seated with no booster, Volvo booster cushion and Volvo highback booster, with variations of the lap belt. The hip interactions and the submarining response of the 6YO PIPER child HBM were studied, by the study of the lap belt interactions with the pelvis and abdominal organs. The abdominal organs were related to the liver and kidneys, and compared to published threshold values. 

    This study showed that the overall robustness of the model was questionable. With respect to kinematics, the model indicated higher robustness, however, when conducted the crash simulations with the 6YO PIPER child HBM, it was concluded that the robustness was low due to repeated premature terminations. The 6YO PIPER child HBM revealed repeated errors such as, mesh distortions, negative volume and shooting nodes. When studying the sensitivity of the 6YO PIPER child HBM, when varying the lap belt angles, as well as changing the type of boosters in addition to vehicle anchorage positions, it could be seen that the 6YO PIPER child HBM was able to capture variations with respect to lap belt positioning. Hence, the model seems to be capable of providing relevant information regarding sensitivity for lap belt variations from the kinematic perspective, in terms of being able to capture kinematic o↵set, submarining and pelvis interaction with the lap belt. However, with respect to predicted abdominal injuries and head injuries, the sensitivity was not as distinct. Some limitations were observed in which the 6YO PIPER child HBM indicated unrealistic predicted injuries related to the head, which was associated with excessive movement of the 6YO PIPER child HBM.

  • 152.
    Elschich, Ahmed
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Thermo-mechanical Fatigue of Electrical Insulation System in Electrical machine2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Electrical machines in electrified heavy-duty vehicles are subjected to dynamic temperature loadings during normal operation due to the different driving conditions. The Electrical Insulation System (EIS) in a stator winding is aged as an effect of these dynamic thermal loads. The thermal loads are usually high constant temperatures and thermal cycling. The high average constant thermal load is well-known in the electrical machine industry but little is known about the effect of temperature cycling. In this project, the ageing of the EIS in stator windings due to temperature cycling is examined.

    In this project, computational simulations of different simplified models that represent the electrical insulation system are made to analyse the thermo-mechanical stresses that is induced due to thermal cycling. Furthermore, a test object was designed and simulated to replicate the stress levels obtained from the simulations. The test object is to ease the physical testing of electrical insulation system. Testing a complete stator takes time and has the disadvantage of having a high mass, therefore a test object is designed and a test method is provided. The results from the finite element analysis indicate that the mechanical stresses induced will affect the lifetime of the electrical insulation system.

    A sensitivity study of several thermal cycling parameters was performed, the stator core length, the cycle rate and the temperature cycle amplitude. The results obtained indicate that the stator core length is too short to have a significant effect on the thermo-mechanical stresses induced. The results of the sensitivity study of the temperature cycle rate and the temperature cycle amplitude showed that these parameters increase the thermo-mechanical stresses induced.

    The results from the simulations of the test object is similar to the results from the simulations of the stator windings, which means that the tests object is valid for testing. The test method that is most appropriate is the power cycling test method, because it replicates the actual application of stator windings. The thermally induced stresses exposing the slot insulation exceeds the yield strength of the material, therefore plastic deformation may occur only after one thermal cycle. The other components in the stator are exposed to stresses below the yield strength.

    The thermally induced stresses exposing the slot insulation are high enough to low cycle fatigue the electrical insulation system, thus thermo-mechanical fatigue is an ageing factor of the electrical insulation system.

  • 153.
    Emanuelsson, Camilla
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Utformning av förvaringar för kapslar: För kaffe te och choklad2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
  • 154. Emanuelsson, Gustav
    Lyftverktyg för att balansera vikt: Lyftverktyg till Falcken Forshaga2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report is a for the bachelor thesis in mechanical engineering at Karlstad University. The project was carried out at Falcken Forshaga outside Karlstad. Falcken Forshaga is a fresh started company that designs lifting tools for the concrete industry. There for they requested help to design an lifting tool for balancing of load. The purpose of this project was to design a tool throughout the product development process which could balance the load. To accomplice this the swedish machine directive had to be followed in order to allow CE-marking. To increase the knowledge about lifting tools a literature study was performed. The result of the study was compiled with the requests from Falcken Forshaga to shape the requirement specification. This document is the backbone for the continued designing of the lifting tool. All concepts developed during the concept generation phase has gone through an elimination matrix. In this matrix has all the concept has been weighed against the requirement specification. This was later presented to the company for decision about which concept to move forward with. When the design layout was done. Calculations and FEM- analysis were made on the critical details. Blueprints have also been made for every part that Falcken Forshaga are going to manufacture in their own workshop.

  • 155.
    Enarsson, Malin
    Karlstad University, Faculty of Technology and Science.
    Ventilation hos TanumsFönster AB: Nulägesbeskrivning och åtgärdsförslag i en industribyggnad2012Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
  • 156.
    Enetjärn, Jacob
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Development of a surfing leash: Development of ankle strap, rail saver and quick release2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this project was to, with the help of supervisors and colleagues, develop a concept suggestion for a surfing leash that is better than the ones found on the market. The purpose was also to create a decision basis for Invencon AB for the continuance of the development of the concept. A planning phase started of the project. In this phase a project plan was created where, for example, the methods to be used were defined and their different time-schedules where specified. A feasibility study was then performed, and the information gathered from the study was summarized into a market requirement specification. This specification was used as a guiding document in the idea generation and during the development of the different concepts. A final concept was chosen at the end of the concept selection phase. This concept was presented to the project commissioner. A handover of relevant documents to the project commissioner was made to facilitate their decision on the continuance of the project. The developed concept has an integrated quick release in the ankle straps clamping function. This allows for the surfer to detach from the surfing leach both safer and faster in a dangerous situation. On both the ankle strap and on the railsaver there are developed attachments where the cord is to be attached. These attachments are designed so that each part of the conceptual surfing leash can be replaced individually. This allows for the surfer to only replace the damaged parts of his surfing leash. A technical requirement specification was also created. This aimed to facilitate the continuance of the project, if the decision is made to continue developing the concept. The conclusion of the project is that it is important to create a comprehensive view over the surfing leashes performance and to where focus should be aimed. A heavy-tailed process was therefore important for the end-result, i.e. to direct a lot of time to the phases that lead up to the concept selection phase. It was also clear that cooperation and discussion was important in a project that aims to create concepts. To be able to discuss ones thoughts and ideas with a project partner has facilitated both the generating and the validating of ideas. To work with a detailed plan and have a clear structure in the work was vital when working close to a project partner.

  • 157.
    Engström, Jane
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Lundmark, Lina
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Att leda för hälsa: En fallstudie ur ledningens perspektiv av Telge Rent AB:s förändringsarbete för minskad sjukfrånvaro och ökad effektivitet rörande yrkesgruppen lokalvårdare2007Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Efter år av ökade sjukskrivningstal inom svenskt arbetsliv syntes under åren 2002-2004 en minskning av långtidssjukskrivningarna. Denna minskning var dock marginell vad gäller kvinnodominerade yrkesgrupper som exempelvis lokalvårdare. (AFA Försäkring, 2006) Vi ville undersöka en organisation, med denna typ av yrkesgrupp, som lyckats sänka sina sjuktal. Vår förhoppning var att finna de hälsobringande påverkansfaktorer som lett till lägre sjukskrivningstal och presentera dessa som underlag för andra organisationers hälsoarbete. Syftet med vår studie är att beskriva Telge Rent AB och deras arbete med att minska medarbetarnas sjukfrånvaro och öka effektiviteten. Vi har valt att studera detta arbetsmiljö- och effektiviseringsarbete ur ett ledningsperspektiv. Vi har genomfört en fallstudie av företaget med hjälp av en kvalitativ ansats och intervjuat ledningsgruppen i Telge Rent AB. Ansatsen valdes för att få en inblick i och en förståelse för hur ledningen tänkt och handlat i förändringsarbetet. Vår analysmetod har varit Grounded Theory-inspirerad. Telge Rent AB har, enligt oss, vidtagit åtgärder som är kontrollerande, stödjande eller både kontrollerande och stödjande. Vår tolkning är att det är syftet med åtgärden som avgör huruvida denna blir stödjande eller kontrollerande. Under studiens gång har vi fått insikt i att sundare levnadsvanor med hjälp av friskvårdsaktiviteter såsom subventionerade träningskort, kostrådgivning m.m. är sätt att försöka öka medarbetarens välmående och minska sjukfrånvaron men det är oftast bara de redan inbitna entusiasterna som utnyttjar detta. De teorier vi valt för vårt problemområde fokuserar på att hälsa är mer än frånvaro av sjukdom, att det snarare är en balans mellan psykiskt och fysiskt välbefinnande. Efter att ha studerat litteratur om ämnen som hälsa, friska arbetsplatser, friskt ledarskap, sjukskrivningar, hälsofrämjande arbete, hälsopromotion, långtidsfrisk m.m. inser vi att det handlar om att bearbeta mer grundläggande faktorer för att uppnå god hälsa. Att skapa ett friskt, lönsamt och produktivt företagsklimat kräver mer än gymkort och fruktkorg. För att uppmärksamma sin egen livsstil och eventuellt ändra den bör varje medarbetare ges möjlighet att arbeta med sin självinsikt, självkänsla och självförtroende, d.v.s. hur man ser på sig själv och sina värderingar. Information och utbildning om hälsa blir sedan nästa steg för att medarbetaren ska kunna ta egna beslut kring sin hälsa. Ett lyckat organisatoriskt hälsoarbete bör komma inifrån medarbetarna själva och arbetsgivarens uppgift är att agera informationsbärare i frågan. Förhållanden som påverkar vår motivation och arbetslust är faktorer som påverkar vår hälsa. Utifrån studerade teorier har vi funnit att krav och kontroll, empowerment, uppmärksamhet och feedback, känsla av sammanhang samt förståelse för arbetets mål och helhet är verktyg i arbetet med att leda för hälsa.

  • 158. Enocksson, Olle
    Heat Storing Solar Cooker: Degree Project for Master of Science in Mechanical Engineering2015Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 159.
    Enström, Marcus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Energianalys av kompressordrivet kylsystem till mobilt energilager: Undersökning av luftburen och vätskeburen kyla av batterier2013Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
  • 160.
    Erhage, Sofie
    Karlstad University.
    Optimization of tear strength in a multi-ply paperboard2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The thesis has been carried out as a part of the Master of Science in mechanical engineering at Karlstads University. The purpose of the study was to evaluate how different variables affect the tearing resistance in a multi-ply paperboard. The paperboard’s final quality is dependent on several different process – and recipe variables and has, in this study, been analyzed with respect to ply grammage, ply composition and refining energies. This was investigated by manufacturing of anisotropic sheets consisting of four plies and isotropic sheets consisting of single-ply sheets. The multi-ply sheets were manufactured where one variable at a time were tested at different values. The single-ply sheets were manufactured of pure pulps with the refining energy being varied. A total of nineteen unique multi-ply sheets and twelve unique single-ply sheets were manufactured.

    All sheets were tested with respect to the properties including tensile strength, bending stiffness, tear strength and delamination strength. The study shows that an improvement in tearing resistance is obtained when the amount of CTMP-pulp in the center plies 2 and 3 decreases simultaneously as the amount of broke-pulp and unbleached chemical pulp in the same plies increases. The consequence of this improvement is reduced thickness and thereby reduced bending stiffness. The study also shows that several pulps has an optimal degree of refining for maximizing tear strength in paperboard.

    The major source of error is believed to be the method of manufacturing. It is also possible that the amount of test points has been too few to be able to see any clear trends for several variables.

  • 161.
    Erhard, Therese
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Energiinvesteringar inom mjukpappersindustrin2009Student thesis
  • 162.
    Erhardsson, Niklas
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Eriksson, Marianne
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Lindell, Per
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Inte bara hel och ren!: Arbetsgivares syn på estetiska kompetenskrav i serviceyrken.2005Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This composition deals with the topic of aesthetic skills and the role it plays within the Swedish service sector. Earlier research has, amongst other things shown that employers increasingly focus on how the employees look, appear and speak- expressed as “looking good, sounding right”. Parts of the labour market today belong to the employers, since there is a significant surplus of people seeking employment for example within the areas of the service sector. Far reaching demands may therefore be placed without protests and the demands on job applicants can even include the physical body.

    The concept aesthetic skills means that the employees look good and sound right. Furthermore, the aesthetic skills of an individual are linked to other skills such as technical, social and emotional skills. The employers use aesthetic skills in view of the fact that the employee should embody the image of the company and thus be part of its representation. This becomes most apparent in workplaces such as hotels, trendy bars, cafés and designer boutiques. Looks, appearance and the choice of apparel of, for example, a bartender, often determines whether the workplace will be seen as trendy or not.

    In our investigation we chose a qualitative approach, which means that we, through interviews, described which role the aesthetic skills plays within the service sector as well as to exemplify the aesthetic demands made by the employers. Our results confirmed earlier research which has shown that aesthetic skills imply that employees looking and sounding right. This in order to represent the enterprise in the best way possible according to the expectations of the customer. Our respondents emphasized that aesthetic demands have significance in extreme forms. Which demands that are most important depends however on the enterprise and the field of work. The most important demand, according to the respondents, is the overall appearance of the employee.

    The employers use recruitment, dress code and group pressure to match the employee with the expectations the employers assume the customers might have. The aesthetic skills are used by employers to minimize the risk of offending the customer. This means that the employees have to adapt their appearance in accordance to the majority of people the enterprise is attempting to target.

  • 163.
    Eriksson, Daniel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Grasping of Non-Rigid Objects: Relation Between Physical Properties and Subjective Experiences2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 164.
    Eriksson, Emelie
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Steby, Martin
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Personliga assistenters psykosociala arbetsmiljö: En kvalitativ studie på ett privat assistansföretag2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

     

     

     

    Personlig assistans är en relativt ny yrkesgrupp som skall utföra grundläggande behov åt brukaren så att denne har möjligheten att leva som alla andra. I arbetsmiljölagen (1977:1160; AML) finns regler om skyldigheter för arbetsgivare att verka för en god arbetsmiljö för sina arbetstagare samt att förebygga ohälsa och olycksfall. Denna lag utgör en rättighetslag för personliga assistenter. Lag (1993:387) om stöd och service till vissa funktionshindrade (LSS) är en rättighetslag för brukare med stora och varaktiga funktionshinder. I denna lag är brukares självbestämmande centralt.

    Det förekommer dock att bestämmelser i dessa lagar hamnar i konflikt med varandra, vilket medför att personliga assistenters rättigheter ställs mot brukares rättigheter. Ingenstans finns det uttryckt att den ena lagen står över den andra men ofta utfaller praktiken i att personliga assistenter i dessa fall får ge vika för brukarens självbestämmande. Detta kan medföra praktiska problem för vårt uppsatsföretags personliga assistenter och dess brukare.

    Företaget som vi skriver vårt examensarbete för är ett privat assistansföretag med omkring 150 anställda personlig assistenter. En av deras viktigaste uppgifter är att matcha den personliga assistentens och brukarens intressen.

    Vi har i denna studie valt att inrikta oss mot psykosocial arbetsmiljö och ämnar genom intervjuer belysa ett antal personliga assistenters arbetssituation och deras tankar och upplevelser kring denna, med fokus på de motsättningar som kan uppstå i rättighetslagarna arbetsmiljölagen (1977:1160, AML) och lag om stöd och service för vissa funktionshindrade (1993:387, LSS). Vi har valt att undersöka och besvara följande frågeställningar:

     

    Vad uttrycker arbetsmiljölagstiftningen om den personliga assistentens rättigheter?

    Vilken inverkan har lagen om stöd och service till vissa funktionshindrade på den personliga assistentens arbetsskyldighet?

    Hur upplever de intervjuade personliga assistenterna sin psykosociala arbetssituation?

    Hur förhåller sig den teoretiska konflikten i praktiken utifrån de anställdas perspektiv?

    Vi analyserar de personliga assistenternas psykosociala arbetsmiljö utifrån Karaseks krav och kontroll, Johnsons vidareutvecklade dimension av modellen med socialt stöd samt även Antonovskys KASAM-modell. Vidare använder vi lagstiftning till grunden för vår uppsats. Utgångspunkten är att en personlig assistent skall utföra de funktionshindrades rätt enligt LSS så länge arbetsuppgifterna inte är farliga, förbjudna eller kränker den personliga assistenten. Vi har kommit fram till att upplevelsen av arbetssituationen för våra intervjupersoner skiljer sig beroende på vilken känsla av sammanhang de känner i arbetet.

  • 165.
    Eriksson, Jessica
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Penetrant and Magnetic Particle Testing with Blue Light: Non-destructive Testing with Fluorescent Media2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 166.
    Eriksson, Lars
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Department of Social and Psychological Studies (from 2013).
    Age, cognitive load, and multimodal effects on driver response to directional warning2019In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 76, p. 147-154Article in journal (Refereed)
    Abstract [en]

    Inattention can be considered a primary cause of vehicular accidents or crashes, and in-car warning signals are applied to alert the driver to take action even in automated vehicles. Because of age related decline of the older driver's abilities, in-car warning signals may need adjustment to the older driver. We therefore investigated the effects of uni-, bi- and trimodal directional warnings (i.e., light, sound, vibration) on young and older drivers' responses in a driving simulator. A young group of 15 drivers (20-25 years of age) and an older group of 16 drivers (65-79 years of age) participated. In the simulations, warning signal was presented at the left, the center, or the right in front of the participant. With a warning at the left, the center, and the right the correct response was to steer to the right, brake, and steer to the left, respectively. The main results showed the older drivers' responses were slower for each type of warning compared with the young drivers' responses. Overall, the responses were slower with an added cognitively loading task. The only multimodal type of warning inducing overall faster response than its constituent warning types was the vibration-sound, and only for the older drivers. Additionally, with the groups' responses collapsed, such a true multimodal effect on response time also showed for the center vibration-sound warning (i.e., braking response). The only multimodal warning showing clear reduction in response errors compared with its constituent warning types was the vibration-sound for the older drivers during extra cognitive load. The main conclusion is that older drivers can benefit from bimodal warning, as compared with unimodal, in terms of faster and more accurate response. The potential superiority of trimodal warning is nevertheless argued.

  • 167.
    Eriksson, Linnea
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    The impact of calculation methods on the gap between predicted and actual energy performance of buildings: Using a thermal simulation model of a building2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The building sector is responsible for almost a quarter of the total carbon dioxide emissions. The urgency to reduce the emissions is reflected in the stricter guidelines which have been set all over the world. To reduce the building sector’s emissions the energy consumption need to be reduced, which can be done in two ways: building new energy efficient buildings or retrofitting of current buildings. Due to the life expectancy of current building stock the largest savings before 2030 will be made through retrofits. For this reliable computational tools are required, and currently there is a gap between the predicted and actual performance of retrofitted buildings. This thesis is going to look into how the computational method is contributing to the performance gap. A building at the RMIT campus in Melbourne, Australia, which is going to be retrofitted through retrofits designed by Siemens, is used. A thermal simulation model of the building was built, and tuned to reflect the pre-retrofit building, and compared against the measured energy performance of the building. The retrofits were then implemented in the simulation model and the gap in the predictions between the simpler computational method used by Siemens in designing the retrofits, and the extensive simulation model was compared. The gap between the computational methods were analysed in order to see how Siemens calculation method contribute to the performance gap. The conclusions which have been drawn are that the simulation model is reflecting the energy use of the building well considering the access of data available during the study. Especially the electricity use is reflected well both in the total annual use, approximately 4 % gap to measured value, and the monthly variation over the year. The total natural gas use is under predicting the annual use, approximately 40 % gap to the measured value, but shows a good correlation to the monthly variation. The electricity use is relatively stable in the simulation model, where the natural gas was sensitive for direct changes to the heating system. The input parameters which have the largest impact in the electricity use are internal gain profiles and the electrical internal gains energy use. Siemens calculation method are contributing to the performance gap through the lack of interaction between the different retrofits, the light retrofit have a noticeable impact on the heating and cooling system of the building. To only use one single period in the regression models can also easily lead to incorrect predictions. The strength of the simulation model is its ability to see the retrofits influence on each other and the possibility for scenario analysis.

  • 168. Eriksson, Lovisa
    Utveckla företagets materialstyrning2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 169. Eriksson, Niklas
    Industriell förvandling – Visualisering av produktionseffektivitet för att minska stopp: Att hitta och eliminera stopp med hjälp av Overall Equipment Effectiveness (OEE)2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 170.
    Eriksson, Patrik
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Undersökning av svetsegenskaper för svetsning med rörtråd kontra homogen tråd2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Welding is a common method for joining of metal or plastic construction parts. This report describes several different weld methods in general terms. The report focuses on the GMAW method, specifically MAG welding.

    A case study has also been performed for the company Wenmec. The task received from the company was to compare the mechanical properties of joints welded with the tube electrode called Nittetsu SM-3A and joints welded with the homogenous electrode called ESAB Aristorod 12.63. Both types of weld joint were welded with the MAG method with an Argon based shielding gas with 18% CO2. The final task of this study is to compare the cost of these electrodes and then help Wenmec to decide which electrode that is the most cost effective.

    Tensile testing, impact testing and fatigue testing were performed on the weld joint samples. The hardnesses, microstructures, failure zones and chemical composition were examined with optical microscopy and SEM.

    The weld time, the amount of consumed electrode and the weld energy was measured during welding. These properties were similar and the differences between the different joints could be ignored.

    Both weld joint types showed similar microstructures and hardnesses. The microstructure was ferrite with carbides or perlite at the grain boundaries. Some silicon oxides were found in the grains.

    The yield strength, ultimate tensile strength and cycles to fatigue failure were similar in the two joint types, but the Aristorod weld joint showed higher impact strength and elongation at break.

    The chemical composition showed that the SM-3A electrode was a metal cored electrode with some additions of deoxidizing elements and a Copper coating. The Aristorod 12.63 electrode also showed the presence of deoxidizing elements and likely had a Titanium based coating. The sheet metal used as the work pieces are called Ruukki Laser 355 MC and is steel with low Carbon content, some Manganese and some impurities.

    The SM-3A electrode was costlier than the 12.63 electrode. This work concluded that the 12.63 electrode was a better alternative for Wenmec due to the lower cost, higher impact strength and higher elongation at break

  • 171.
    Eriksson Röhnisch, Kasper
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    FEM Analytisk studie av kilar för riktverk: FEM Analytisk studie av konstruktionsändringar för delkomponenten kilkasset i riktverk 1, Formatsträcka 4 SSAB Borlänge2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 172.
    Eriksson, Sebastian
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Bestämning av tryckfallet vid pneumatisk transport av sågspån: Genom simulering och praktiska försök2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The reduced availability of fossil fuels and the increasing energy demand in the world creates a need to develop solutions that are financial and environment sustainable. Biofuels has grown to become one of the most important renewable energy sources in the target towards a carbon neutral society. Although the high moisture content ranging between 50-150% for unprocessed biofuels causes problems. As a result, there is a drying demand that has to be solved in an energy efficient and environmental friendly way. As of today, the drying of biomaterials pre pelletizing stands for 25 % of the total cost in pellets production.

    The cost to dry biomaterials makes it important to improve the efficiency of the drying process. Simultaneously the drying process causes emissions of hazardous substances such as terpenes. The drying must also in a consistent quality so that the biomaterial is made to hold constant and uniform moisture content to enable efficient processing. Depending on the usage of the biomaterial, there is a different demand of the final moisture content before processing. The ideal moisture content for combustion for example ranges between 15-25 %, while pyrolysis would rather have moisture content between 5-10 % for effective and high quality processing. The ideal moisture content pre pelletizing is between the two mentioned processes, namely 8-12 %. Three common dryers used to dry biomaterials are rotary dryers, conveyor dryer and pneumatic dryer.

    In this thesis the pressure drop in a pneumatic dryer is predicted. A pneumatic dryer a airflow simultaneously conveys and dries the wet material. Perks of a pneumatic dryer is the short amount of time required to dry the material, and simultaneously deliver uniform moisture content. The short time required also contributes to minimize the emissions of volatile organic compounds (VOC) like terpenes compared to the other two mentioned types of dryers and the risk of fire during the drying process. Although because of the high airflow compared to the material flow, pneumatic drying is costly and has difficulties with separating the dried material from the airflow.

    A model to predict the pressure drop in a pneumatic dryer was created. The simulated pressure drop was then verified against a practically measured pressure drop for a pneumatic dryer. In this way a model was created to examine the pressure drop for a variety of material- and airflows. The thesis suggests how to calculate the pressure drop and velocities for the accelerating region, steady state and U-bend of pneumatic conveying. To better predict the pressure drop according to the actually measured pressure drop a correction equation was presented.

    The results of the model are consistent with the research in pneumatic conveying and drying. The model gave with the usage of the correction equation a very good prediction on how the pressure drop varied over the length of the pneumatic conveying. The pressure drop was as expected larger as the airflow or material flow increased. As the sawdust accelerated on 0,4-0,6 meters there is required more points of measurements in the region between 0-0,6 meters to better establish exactly how the pressure drop in the accelerating region varies. The difference between the practically measured and the simulated pressure drop was never exceeded 7,0 % for the different flows investigated in this thesis. When disregarding the measure point at 0,4 meters the difference between measured and simulated pressure drop never exceeded 4,4 %. If one would include the heat transfer between the material- and airflow, the model could be used to predict the energy consumption and required length to achieve desired moisture content on the material.

  • 173.
    Eriksson, Veronica
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Working Life Science.
    Undersköterskors psykosociala arbetsmiljö: En kvalitativ studie inom offentlig sektor2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna undersökning är att studera hur undersköterskor som arbetar inomhemtjänsten i offentlig sektor upplever sin psykosociala arbetsmiljö. Undersökningensfrågeställning formulerades utifrån syftet därmed till ”hur upplever undersköterskor inomhemtjänsten i den offentliga sektorn sin psykosociala arbetsmiljö?”. Tidigare studier har visatatt denna yrkesgrupp ofta arbetar under förhållanden som är slitsamma och psykisktpåfrestande, men ändå finner en stor meningsfullhet och trivsel i vad de gör.

    För att undersöka frågeställningen har det utgåtts från etablerade teorier om ämnet. Demodeller som använts är Karaseks krav- kontroll och stödmodell samt Antonovskys känsla avsammanhang (KASAM). I undersökningen har även ytterligare forskning kring psykosocialarbetsmiljö och stress studerats för att skapa en bred utgångspunkt. För att få fram ett djuptempiriskt material har en kvalitativ forskningsmetod med intervjuer använts. För att sedan fåfram kärnan ur intervjuerna har dessa kodats och analyserats till olika teman.

    De teman som urskilts ur det empiriska materialet är egenkontroll, arbetskrav, stöd, stress,utveckling samt trivsel, vilka senare formulerats till underrubriker som presenteras i kapitletAnalys och resultat. Kapitlet presenteras med hjälp av citat från intervjuerna. Resultatet frånundersökningen visade att undersköterskorna upplever sig ha en tillfredsställande psykosocialarbetsmiljö. Den aspekt de värdesätter mest är gemenskapen och det sociala stöd de får frånvarandra. I koppling till de teoretiska modeller som använts visade studien attundersköterskorna har kollektiva aktiva arbeten, på gränsen till högstressarbeten, och en starkkänsla av sammanhang.

  • 174.
    Eriksson, Viktor
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Numerical Simulation of Ductile Cast Iron Fracture: A parameterization of the material model *MAT_224 in the FE-code LS-DYNA2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In crashes, fracture of Ductile Cast Iron (DCI) components can have a big influence on the global behaviour of the structure and the survival probability of the driver.

    In this thesis the material model *MAT_224 is parameterized for one ferritic-pearlitic grade, SS-0727-02, of DCI. The aim is to better describe the fracture and yielding of DCI components in crash simulations using the FE-code LS-DYNA. This is done by mechanical testing and simulations where the hardening behaviour and failure criteria are quantified. The failure criteria are defined by a failure strain surface, which depends on the stress triaxiality and the lode parameter.

    Tensile and torsion testing were performed to determine the model material parameters. Several different types of test specimens have been designed and tested. The goal when designing the specimen is to have a large variety of stress states at failure. To evaluate the parameterized material model three different types of validations tests, using bending and component testing, have been performed.

    The parameterized material model is able to predict the force at failure for several different stress states in a satisfying way. Still, the final failure is not predicted satisfactorily all the way, probably due to technological reasons. Thus, more mechanical test is recommended in order to validate the model further. 

  • 175.
    Ernebro, Susanna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Förbättring av interna projektöverlämningar: Framtagning av rutiner samt upprättande av en enhetlig arbetsmodell2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This Degree Project has been carried out during the spring semester of 2016 for the Degree of Science in Innovation and Design Engineering at the faculty of health, science and technology at Karlstad University. Most of the work has been done at Emerson Process Management AB in Karlstad.

    The purpose of the project was to improve the company’s internal project handovers. In order to make the project handovers between the project department and the service department more uniform and to be able to assure the quality of them, a manual has been developed. The manual includes information about the handover procedure, the different tasks that has to be performed during the project handover and also who is responsible for these tasks. The manual also includes information about the participants that are required to attend the handover meetings, agenda topics and information about what type of handover documents that should be handed over to the service organization during the handover meeting.

    A template for a folder structure has also been made, that is supposed to be used by project managers to store the documents that the service department will need after the handover. This templates, including the documents involving the projects, is then to be copied and stored on a server that the service department can access. On this server, the staff working in the service department can sort the different templates in a way that they desire to make it easier for them to find the documents they need. The fact that all project managers uses the same folder structure, staff at the service department will easily find the information they need, leading to large cuts in time and resources for the whole company. It also helps to ensure that no documents are forgotten or lost in the handover process.

    The feasibility study of the project has involved a lot of gathering of information and interviews with staff from different departments of the company. The feasibility study was then compiled in a requirement specification and a Service Blueprint. Based on this material, a number of solutions could then be carried out. Through various elimination methods, weightings and evaluation of the developed solutions, a final concept could then be chosen. The selected concept was tested and a final adjustment was made to get as good a result as possible. A dialogue was conducted with staff at Emerson Process Management AB throughout the project in order to get a result that was adapted to the company's operations.

    A proposal was also submitted to Emerson Process Management AB on how the implementation of these new procedures and tools would be realized. This was made so that all concerned parties in the best way possible could accept the change and implement it in a positive and easy-to-use manner.

  • 176.
    Ernstson, Emilie
    et al.
    Karlstad University, Division for Business and Economics.
    Harrison, Daniel
    Karlstad University, Division for Business and Economics.
    Motion och friskvårdstimmen: En studie av motionsvanor på- och utanför arbetet2006Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Denna studie handlar om personalvårdsförmånen friskvårdstimmen parallellt med motionsvanor i allmänhet. Vi har i studien utgått från ett generellt hälsoperspektiv, för att sedan smalna av till att inrikta oss på hälsa inom arbetslivet, närmare bestämt friskvårdstimmen. Vår studie följer därmed en så kallad ”Top-down modell”. Syftet med denna studie är att undersöka vilka som nyttjar friskvårdstimmen samt vad som motiverar individer till att motionera. För att utforska detta har vi utgått från tre frågeställningar: vilken kategori av människor är det som motionerar och använder sig av friskvårdstimmen? Vad motiverar dessa individer? Hur kan man motivera anställda till motion och användandet av friskvårdstimmen?

    Studien är baserad på en kvantitativ undersökning i enkätform, inom en statlig organisation i centrala Karlstad. 169 respondenter besvarade enkäten. Vi anser oss ha ett brett urval då hela kontoret var med i undersökningen, vilket gjorde att vi fick en spridd fördelning i ålder och kön.

    Bland våra respondenter kan vi se att det finns en positiv inställning och en hög medvetenhet till motionens och friskvårdstimmens effekter. Dock är nyttjandet i praktiken inte lika stort i förhållande till respondenternas medvetenhet. Vi ser att man har en omgivande miljö som är motionsfrämjade, inte minst i och med att organisationen erbjuder friskvårdstimmen som personalvårdsförmån. Av de framkomna resultaten kan vi bland annat se att ålder är en bidragande faktor till hur mycket man använder friskvårdstimmen. Av våra respondenter motionerar kvinnor mer än män och motivationsfaktorer till motionen är för att hålla sig i form och för att förebygga skador och sjukdomar. Vidare är tidsbrist en bidragande orsak till varför man inte motionerar och nyttjar friskvårdstimmen.

    Vi menar att om organisationen vill utveckla friskvården bör man uppmärksamma att till en början koncentrera sig på dem som aldrig nyttjar friskvårdstimmen. Att erbjuda personlig rådgivning till dessa anställda anser vi skulle kunna vara en tänkbar motivationsfaktor till ökad motion. Detta eftersom det i vår studie framkom att mer information om motion inte skulle leda till ett högre motionsutövande. Vi är medvetna om att endast friskvårdstimmen i sig inte kan förändra ett beteendemönster, men att den kan vara ett inledande steg till att förbättra sin levnadsstil.

  • 177. Fagrell, Fredrik
    Nya driftstrategier för minskad användning av bioolja under tidsperioder med spetslaster: Driftkartläggning, modellering, simulering och visualisering av Trollhättan Energis fjärrvärmeproduktion 2015–20172018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The world agrees that humans causes negative climate changes. Combustion of fuels releases greenhouse gases. These gases contribute to heftier changes of the weather, flooding and expanding deserts. By reducing emissions of greenhouse gases climate change can be slowed down. That demands effective usage of fuel resources. District heating is a well-established system for heating up housing and water, where combustion of fuels is the source of energy. Year 2017 Trollhättan Energi AB (TEAB) produced 368 GWh district heat. The company has transitioned to rely mainly on wood chips and biooil, two renewable sources of energy. Now there is also an interest in operational improvements of their heat plants.

    This study investigates time periods where biooil could have been replaced by wood chips. Wood chip is the cheaper fuel; therefore, it is of interest to increase its share of the heat production. If that’s achieved, TEAB can keep offering customers lower-priced district heating. With data from 2015–2017 a model based on linear programming was developed in MATLAB. The results from the model and analyzes of data were used to develop new operational strategies. Differences in emissions and operations costs between the data and the model during the observed time periods are presented as well.

    The results show that most of the observed time periods could have been covered with the help of solid fuel boilers and the energy storage tank. This could have been accomplished through:

    • Co-operating more than one solid fuel boiler during time periods with a lower heat demand (<68,3 MW)
    • Using Stallbacka P4 (StbP4) and Kronogården P3 (KronoP3) more since their operating costs are low and they can run on relatively low effect compared to Stallbacka P3 (StbP3) and Lextorp P4 (LexP4)
    • Prioritizing loading up the energy storage tank before shutting down a solid fuel boiler, provided it is not fully loaded

    The smaller solid fuel boilers, KronoP3 and StbP4, co-operate well in pairs with the larger solid fuel boilers, StbP3 and LexP4. Especially during time periods where one large solid fuel boiler is not enough to cover peak loads.

    During the study it has been observed that the maximum effect of the boilers is rarely achieved, and that the energy storage tank is not emptied during several time periods. If the operations team becomes more consequent in achieving high effect output from the boilers and emptying the energy storage tank completely the usage of biooil can be reduced.

    To achieve the solutions suggested with the model, a tool for predictions that gives prognoses of the heat demand could be handy. The tool developed in this study shows potential, despite the low amount of time and resources put into it. The most important is to test the tool and actively integrate it in production planning routines.

    The solutions presented show a potential of saving 2 Mkr during 2015–2017 if the suggested operating strategies would have been adapted. The model did not calculate positive economical outcomes for all of the observed time periods. This encourage a study with a widened time-perspective covering a full year of operations. The size of the potential economical saving is considered to be low, around 0,75 % of the total operations cost for 2015–2017. The solutions do not require an investment which could increase the incentives to review the operations and production planning as it is of today.

    With a lower amount of biooil and an increased amount of wood chips, the emissions of CO2-eq, CO and NOx would have potentially increased during the examined years. A deeper analysis of these emissions is suggested to determine the effects of increased emissions. If the emissions levels of NOx exceed a certain value, TEAB could be required to pay extra fees for these emissions, which lowers the profitability.

    The model has potential for improvements and more areas of use. The opinion after the study is that together with prediction tools, the production planning can be made easier. With a prediction tool, new ideas of operations can be developed, tested in advance and also include more operating hours.

  • 178.
    Fariborz, Shahriar
    Amirkabir University, Iran.
    Free vibration of a rod undergoing finite strain2012In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 382, no 1Article in journal (Refereed)
    Abstract [en]

    The finite strain longitudinal free vibration of a rod is studied. Utilizing second Piola-Kirchhoff stress and Green strain tensors, the equation of motion is written in terms of displacement in reference configuration. Three different types of homogenous boundary conditions may be considered for the rod, leading to three nonlinear eigenvalue problems. The series solutions with three terms satisfying the boundary conditions are utilized and the relationships between amplitudes of vibration are obtained by means of the Galerkin method. The backbone curves are drawn and the internal resonance between different modes of vibration is analyzed.

  • 179.
    Felix, Olsson
    Karlstad University.
    Vändning av trafikelement: Konstruktion åt företaget Forshaga Svets & Smide2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Stenteknik i Karlstad AB is a company that manufactures traffic elements. These traffic elements are currently turned 180 degrees by an overhead crane and are considered to be time consuming and unsafe. In order to make the process more efficiently and safer, Stenteknik i Karlstad AB has requested a construction that offer this. Forshaga Svets & Smide has been assigned this task and this master thesis will generate a solution for them.

    The objective of the project is to find a solution that safe and efficiently turns the elements and thereby improves the working environment, reduces the production costs and lead times. The solution will also be produced in CAD format which will then be handed over to Forshaga Svets & Smide.

    The project began with a pilot study to create an overview of the current situation and obtain information about the subject. A requirement specification, containing requirements for the construction, was created by the information produced from the pilot study together with the wishes made by Stenteknik i Karlstad AB. The requirement specification has been the basis for this project.

    Different concepts have been created through concept generation methods. The concepts developed have been modeled so that they can then be presented to the project supervisor who either elaborated, corrected or rejected them.

    The “Hinge” became the final concept that is not in need of either engine or hydraulics. The Hinge is a concept based on an overhead crane to turn the traffic elements. With this concept the turning takes place in a safer and more efficient way than before.

    The project has followed the various stage of the product development process that have been studied during the program for Mechanical Engineering. Approximately 600 working hours have been spent on this project.

  • 180.
    Fellenius, Malin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Reduction of vibration transmitted through car seats: A study to reduce test drivers’ whole-body vibrations at Volvo Car Group’s test facility2017Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Present thesis will concentrate on the attention to reduce the input of whole-body vibrations transmitted to test drivers in durability tests. On behalf of Volvo Cars, the purpose has been to develop a concept solution on the driver's seat. Solving this problem is significant due to test driver’s safety and theirs ergonomically conditions. This project is conducted as a Bachelor of Science thesis for the Innovation & design engineer program at Karlstad University.   

    The assignment is in collaboration with the research and development department Proving Ground Testing Group located outside Borås on their test facility, Hällered Proving Ground (HPG). Where they perform endurance tests on rough roads with complete vehicles. The main goal of this project is to increase the time drivers can actively drive the test cars each day, as well as reduce the exposure of whole-body vibration transmitted to test drivers.  

    The project has been carried out through the Engineering Design Process, which is a substantial model for working with creativity during product development. The report consists of a pre-study in areas like dynamic systems of vibration, ergonomics, previous research, benchmarking and seat structure. This was achieved by identifying the problem areas in an early stage. A number of concepts solutions were evaluated and compared according to implementability and realizability. The final decision was made on a concept, resulted in changing the current foam in the seat. Thereafter, it presents the evaluation of materials throughout the material database CES EduPack and through product research.    

    The last part of the report presents results from laboratory testings and a field test. The objective was to determine which arrangement provided the best isolation throughout different combinations of materials/products and material thicknesses.

    The result of the test showed that an increase of material thickness was the optimal solution. Polyurethane (PUR) foam is best suited for this and factors such as material properties and combination of materials has less or none impact on reducing whole-body vibrations. Therefore, the current foam can maybe be enough, but it needs to be evaluated further. This solution doesn't do any major changes to the cars specification and therefore the cars can be evaluated as before.  

    Further development is to build a prototype with thicker dimensions and implement it in a test vehicle. Subsequently verifying a decrease of exposure from whole-body vibrations, in the form of a real-life test.

    The solution is intended solely for test vehicles at Volvo’s endurance track facility at Hällered. The assignment was to facilitate working conditions for test drivers and make the work more efficient. The thesis purpose was to achieve a sustainable solution, according to Volvo Cars` requirements to reduce exposure from whole-body vibrations and this project is therefore fulfilled. It was important that the solution was easy to implement and can be applied on all platforms, correspondently be used on future test cars from Volvo.  

  • 181.
    Fernandes, R
    et al.
    Texas A&M University.
    El-Borgi,
    Texas A&M University at Qatar.
    Mousavi, Mahmoud
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Reddy, JN
    Texas A&M University.
    Mechmoum,
    Texas A&M University at Qatar.
    Nonlinear size-dependent longitudinal vibration of carbon nanotubesembedded in an elastic medium2017In: Physica E: Low-dimensional Systems and Nanostructures, ISSN 1386-9477, Vol. 88, p. 18-25Article in journal (Refereed)
    Abstract [en]

    In this paper, we study the longitudinal linear and nonlinear free vibration response of a single walled carbonnanotube (CNT) embedded in an elastic medium subjected to different boundary conditions. This formulation isbased on a large deformation analysis in which the linear and nonlinear von Kármán strains and their gradientare included in the expression of the strain energy and the velocity and its gradient are taken into account in theexpression of the kinetic energy. Therefore, static and kinetic length scales associated with both energies areintroduced to model size effects. The governing motion equation along with the boundary conditions are derivedusing Hamilton's principle. Closed-form solutions for the linear free vibration problem of the embedded CNTrod are first obtained. Then, the nonlinear free vibration response is investigated for various values of lengthscales using the method of multiple scales.

  • 182.
    Fernandes, Ralston
    et al.
    Texas A&M University at Qatar.
    Mousavi, Mahmoud
    Aalto University, Finland.
    El-Borgi, Sami
    University of Carthage, Tunisia.
    Free and forced vibration nonlinear analysis of a microbeam using finite strain and velocity gradients theory2016In: Acta Mechanica, ISSN 0001-5970, E-ISSN 1619-6937, Vol. 227, no 9, p. 2657-2670Article in journal (Refereed)
    Abstract [en]

    A nonlinear finite strain and velocity gradient framework is formulated for the Euler-€Bernoulli beam theory. This formulation includes finite strain and the strain gradient within the strain energy generalization as well as velocity and its gradient within the kinetic energy generalization. Consequently, static and kinetic internal length scales are developed to capture size effects. The governing equation with initial and boundary conditions is obtained using the variational approach. Free and forced vibration of a simply supported nanobeam is studied for different values of static and kinetic length scales using the method of multiple scales.

  • 183.
    Fernström, Vilma
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Böjning av kräppschabern vid mjukpapperstillverkning: Ändring av kräppvinkeln2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the tissue industry, it is important to develop and maintain as good a quality as possible on the products in order to stay on the market. It is therefore important to have knowledge of all the steps of the manufacturing process and how they affect the final result. An important part of the production is the creping process, which largely gives the paper its properties and quality. It is in this stage of manufacturing process that the structure of the paper is determined. This means that a great focus is to understand and develop the creping process.

     

    This report is made in collaboration with a tissue manufacturer who recently discovered a greater demand from customers to participate in and control the settings in their projects. Since there is a lack of knowledge of how different factors affect the creping, uncertainty has arisen. The purpose of this report is to contribute with the knowledge required about the creping process in order to reduce uncertainty in the company and satisfy the customers' demand and needs. In the creping process, creping blade is the most important component to examine as it is this blade that performs the creping itself.

     

    The most relevant factors for the creping blades settings are selected to be examined in this report. The analysis of the parameters is performed by varying one parameter at a time and then checking how the bending of the creping blade looks. With the deflection of the blade, a crepe angle can be calculated in order to highlight the relationship between the chosen parameters and the crepe angle. This will be accomplished by using three different methods, the results of which are then compared with each other to determine the calculated conditions. The different methods who are used is an analytical calculation based on the linear elasticity equation and two studies in FEM programs where the blade geometry is modeled.

     

    Plots are designed, displaying values ​​from the different analysis’s as a basis. A chart for each parameter is created, the charts show how the crepe angle changes as the parameter varies within the selected intervals. All parameters examined were found to affect the crepe angle more or less, but all at a level that makes them relevant to the setting of the creping blade as a certain desired quality is required. After a comparison of the results from the different methods, some deviations could be found. However, these deviations are not significant and may therefore be ignored. There are many possible reasons for these deviations such as e.g. various presumptions and computational differences. The conclusions that can be made about this report are that all the parameters that were examined have a significant role in the reduction of the crepe angle and that the results from the various methods gave consistent results. In future investigations, therefore, the most convenient of the methods tested may be recommended.

     

  • 184.
    Ferreira Neto, Luiz Benicio
    Karlstad University, Faculty of Health, Science and Technology (starting 2013). Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Vertikaltransportör: Till pappersrullar2013Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This project includes a thesis performed at Karlstad University in spring 2013. The thesis is included in the mechanical engineering program and contains 22.5 university points, which is equivalent to 480 hours of work including self-study.

     

    This work has implemented by the student Luiz Ferreira in cooperation with the firm Camatec Industriteknik AB in Karlstad.

     

    The purpose of this project has been that the company Camatec wants to offer their customers a standard vertical transporter. This transporter must be able to transport paper rolls, which can weigh up to 5 tons, between two floors. The objective with this project has been to prepare a complete set of drawings for a vertical transporter and a price estimate of all its components. This transporter must fit into a given elevator shaft but also be able to adapt into different dimensions.

     

    A vertical transporter has been developed with help of different methods including 3D-modeling, Finite Element Method and strength calculations.

     

    The total development of the transporter has been divided into several areas of constructions:

    • Receiver for paper rolls

    An existing receiver for paper rolls has been redesigned and adapted into the new construction.

    • Frame

    A frame has been developed including I-beams, flat bars and hollow structural sections which have been connected with welding and bolts to hold the receiver.

    • Mechanism

    A mechanism of shaft and bearings, which allow the receiver to rotate so the paper rolls can relief in a facility way, has been designed.

    • Guiding

    A guiding section has been developed, in which t-grids have been used to guide the transporter along the given elevator shaft.

    • Vibration damper

    Two ANB 100 vibration dampers with a hardness of 70 Shore have been used to suppress one side of the receiver so it can rotate.

    • Hoist

    An appropriate rope hoist for this transporter has been discussed with the firm ABUS Kransystem AB in Karlstad. This hoist carries almost the entire transporter.

     

    Standard components are used through the entire project and these have been estimated at an amount of about 306 000 Swedish crowns, where prices for the existing solution of receiver, processing and installation are not included.

  • 185.
    Flod, Jenny
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Utveckling av förpackning för livsmedelsrelaterade vätskor: Produktutvecklingsprojekt av ytterförpackning för vätskor med utgångspunkt i Bag-in-box konceptet.2016Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report describes the process of developing a new package for food-related liquids. The assignment is done on behalf of the design and branding agency Motherland and is a Bachelor of Science degree in Innovation and Design at Karlstad University. The client wants to find a new design for packaging where the end product is similar to the Bag-in- box concept.

    The Bag-in-box concept is good in many ways, with its block-shaped design almost pallet optimised, it has a simple construction, less environmental impact than glass, aluminum and PET bottles and less expensive to produce. In spite of its popularity in Sweden and well as the rest of the world, the pre-study shows that there are many users who think that the concept has its flaws. Common users claim the package does not reflect the contents and is difficult to empty and disassemble. The package can only be used standing at the edge of the table.

    The goal of this product development project is to apply the designprocess to find one or more prototypes with new design which meets the demands of the consumers. The project is limited to finding a new solution on the outer packaging and do not take into account the dosing function. The product must be suited for storage and transport to meet the requirements of sustainable development.

    The feasibility study gave insight and knowledge of the output concept, the facts surrounding a number of food related liquids, information about effective tools for idea development, sustainable development and the approach to manufacture an environmentally friendly packaging. Facts gathered through literature studies, study, survey, form studies, component analysis and visits knowledgeable in relevant areas. The study resulted in a specification that was used as a guide in the product development process.

    The project resulted in two prototypes with the same engineering design and volume but with different dimensions on height and width. They have a new design and a new mindset when it comes drain but have the same final function as the starting product, to protect the fluid, contain fluid, moving liquids, and dosing liquid. They have an opening and resealable lid that allows the user to control the content and facilitates proper recycling. It enables the packaging to be easily taken out and thus simplify the emptying of all content.

    Sketching and modeling has been of great help in the work and its results. 

  • 186.
    Fogdeberg, Sofia
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Working Life Science.
    Kvinnor och män inom teknikbranschen: En kvantitativ undersökning med fokus på kvinnors arbetsförhållanden på mansdominerade arbetsplatser och "metoo" kampanjens påverkan2019Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
  • 187.
    Forsberg, Åsa
    Karlstad University, Faculty of Technology and Science.
    Energieffektivisering i ett verkstadsföretag: En analys av energibesparande åtgärder samt uppvärmnings- och kylsystems driftkostnader och koldioxidutsläpp2010Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The energy use in a workshop company has been examined in this work in order to find areas for energy efficiency improvement. The combined oil and electricity heating in the company were compared with other alternative heating systems including cooling of the premises in following combinations:

    1. Ground source heat pump for heating and cooling
    2. District heating and absorption cooling
    3. District heating and low temperate surface water cooling

    Energy use, operation costs and carbon dioxide emissions were calculated for the current heating systems and the three alternatives including cooling. The ground source heat pump for heating and cooling decreases bought energy with 34 MWh annually compared to current heating only. The district heating and low temperate surface water cooling has the largest reduction of operation cost and carbon dioxide. The operation cost decreases with 42 kSEK and the carbon dioxide with 43 metric ton CO2 annually. The differences between the alternatives were smaller concerning the operation costs. The ground source heat pump alternative had smaller reductions of carbon dioxide than the other two alternatives with district heating.

    An alternative heating and cooling system can also lead to alternative energy use. The choice is between electrical or heat energy. A weighting can be done to evaluate the energy use for heating on basis of how much energy is needed in order to generate the energy the end user buys. A 2.5 factor for electrical energy entails the alternative with district heating and low temperate surface water cooling gets the lowest heating and cooling energy in comparison.

    An inventory of the lighting was also done. The company has already an energy effective lighting but yet another saving of 2 MWh can be done annually without replacement of armatures.

    Finally, the operation time of the compressor was calculated with a mean value of 11 hours per day. The compressor delivers pressure air to machines and tools. There can be a great demand for pressure air in the workshop but the operation time can also be an indication of leakage in the air net.

  • 188.
    Forselius Eriksson, Jenni
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Ulvan, Ida-Karin
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Balans mellan arbetsliv och övrigt liv: - en studie om manliga småföretagare som lever självständighetens livsform2006Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Människan som lever i dagens samhälle och är verksam i arbetslivet har inte kunnat undgå den ökade kommunikationen som skett med den ökade tillgängligheten som följd. Detta är något som vi menar påverkar upprätthållandet av balans. Vår förförståelse sade oss innan denna undersökning genomfördes, att det är svårt för småföretagare att upprätthålla balans mellan arbetsliv och övrigt liv. Vi var därför intresserade av att göra en studie för att ta reda på hur detta såg ut, och vi valde att genomföra en kvalitativ undersökning för att få en inblick i detta.

    Undersökningens syfte var att ta reda på hur balansen såg ut mellan arbetsliv och övrigt liv hos manliga småföretagare som helt eller delvis lever självständighetens livsform?

    Självständighetens livsform är ett begrepp som ingår i livsformsteorin. Denna teori är skapad för att få en uppfattning om människors vardag. Människor som lever olika livsformer har olika värderingar, handlingsmönster och behov. Vad en person avser med ”det goda livet” som lever en livsform kan för en person som lever en annan livsform vara något helt annat. Livsformsteorin blev ett verktyg för oss att titta på balans hos småföretagare som lever självständighetens livsform. Vi valde att som tillvägagångssätt utgå ifrån livsformsteorin samt att använda oss av en teori om balans. För att kunna besvara undersökningens syfte genomfördes sex intervjuer på manliga småföretagare, vilka lever självständighetens livsform.

    I undersökningen kom vi fram till att balans mellan arbetsliv och övrigt liv för småföretagare som lever självständighetens livsform är något väldigt individuellt. Intervjupersonerna har sin egen uppfattning om vad balans innebär och hur de ska göra för att uppnå den. Problematiken i att uppnå balans utifrån den teori som vi utgått ifrån var att småföretagarna inte hade några skarpa gränsdragningar mellan arbetsliv och övrigt liv.

  • 189.
    Forsell, Jennie
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Thim, Emelie
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Alkohol- och drogpolicy: Effektivt verktyg eller dammigt dokument i byrålådan?2008Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Syftet med denna uppsats är att genom intervjuer med medarbetare i två olika organisationer undersöka om, och i sådana fall hur, olika delar i en organisation kan påverka arbetsgivare och arbetstagares förhållningssätt till frågor rörande alkohol och arbetet med drog- och alkoholpolicyn. Vidare har syftet varit att se vilken roll denna policy spelar i arbetet med dessa frågor.

    De frågeställningar vi har för avsikt att besvara är följande:

    • Hur förhåller sig medlemmar i organisationen till problem rörande alkohol?

    • Finns likheter eller skillnader mellan hur medlemmar förhåller sig till en organisations alkoholpolicy respektive hur de agerar i praktiken?

    • Vad är det som påverkar dessa förhållningssätt?

    De resultat vi har fått fram pekar på tydliga tendenser till att alkohol- och drogpolicyn inte används som ett verktyg i frågor rörande alkohol och droger i de undersökta organisationerna. Trots detta stämmer medarbetares tillvägagångssätt många gånger överens med det som står i respektive organisations policy. Detta beror till största del på dokumentens vaga utformning. Vi har hittat fyra faktorer som är avgörande för hur förhållningssättet till dessa frågor påverkas. Dessa är ansvar, ledarskap, kommunikation och medarbetarinflytande.

  • 190. Fritz, Lukas
    Surf Leash: Product Development of the Cord and Assembly2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor thesis treats the product development process in general and the product development of a surf leash in particular. The thesis mainly concerns the product development of the surf leash cord and assembly.

    The product development process was initiated in South Africa, where problems with the surf leashes provided on today’s market was experienced. They get worn out to quick and it is expensive to replace a complete surf leash, as it is not possible to replace a broken part individually.

    The product development project aimed to obtain a well-defined final concept with an associated technical requirement specification for the surf leash, within the given time frame. To do so, the product development process was divided into four different phases, project plan, market requirement specification, concept selection and technical requirement specification.

    During the project plan phase, a plan for the product development process was created. Necessary methods and tools were selected for respective phase and a time schedule was created.

    The market requirement specification is mainly based on a market survey which was performed. The market survey contributed with valuable information, which has been used throughout the complete product development process to increase the costumer value in an efficient way.

    The concept selection is based on the outcome of the idea generation process, which were generated with regard to the requirements and desires in the market requirement specification. Various matrices were used to narrow the range of possible solution and to find the optimal concept for the cord and assembly.

    The concept selection phase resulted in a cord with a core of an elastic material with a protective cover in a material with less elasticity. This is made to protect the inner core from getting stretched-out and not return to its original length, the outer cover can also be constructed to make the cord less prone to tangle. The assembly consists of a male connector with a small trace which is connected to a receiver with a double pin lock mechanism. This creates a module-based, rotational free assembly which is easy to attach and detach. Thus, the surf leash can be optimized after personal preferences and allows for a broken part to be replaced individually.

    The technical requirement specification is based on available information and can be used as a basis for future work with layout- and detail construction.

  • 191.
    Frodeson, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013). Environmental and Energy Systems.
    Towards Understanding the Pelletizing Process of Biomass: Perspectives on Energy Efficiency and Pelletability of Pure Substances2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The use of fossil resources has to decrease and the use of renewable resources has to increase significantly to mitigate the climate change. In this change towards more renewable resources, biomasses will play an important role, both for energy use and for products. Thus, the utilization of biomasses must be optimized, both linked to which biomass species that are used, as well as the actual production processes. This thesis relates to the production of lignocellulosic biomass pellets, with the purpose to increase the understanding of how a pellet process can be improved. 

    There are many benefits to pelletize the biomass, such as increased density, more economical transports solutions and increased doseability. However, there is a lack of knowledge on how different biomass species affect the actual pelletizing. This causes pellet producers to strive for a feedstock with a chemical composition that is as uniform as possible, which reduces the possibility of increasing intake of, for example, seasonal or residual products of other kinds.

    If pellet producers can handle, predict and combine different biomaterials over time without stopping the production, new ways of acquiring raw materials for production would be possible. This will be important for future pellet producers, as the general use of biomasses will increase, so will the competition of the raw material. It will also be of importance in developing countries, which have a greater variation in wood species than today's large pellets producing countries. 

    This work has been focused on understanding biomasses pelletability, and the method has been to start with components such as, cellulose, hemicellulose, lignin etc. Results shows that there is a significant difference between the hemicelluloses, xylan and glucomannan, in terms of pelletability. During pelletizing, xylan changes its form, generates hard pellets and, correlated to pelletability, xylan are affected by actual moisture content or added water to the process. Glucomannan, however, shows the opposite, a low impact on pelletability and a minimal impact from water during the pelletizing process. A difference that can explain the difference in pelletability, between hardwood and softwood. 

    Solutions to improve the pelletizing process have also been studied. One result is that adding oxidized starch additive, reduces the energy consumption in the pelletizer and increasing the durability of the pellets, more than native starches. Another result is that a two-stage drying technique, reduces the heat power consumption per tonne of dried materialand at the same time increases the drying capacity. Also, the possibilities for a pellet producer to handle, predict and combine different biomaterials has been studied. Presented results show howbiomasses from Zambia can be used as an single resource or in different resources combinations in a pellet production. 

    Finally, a recommendation to pellet researchers to include the cellulose material, Avicel, in single pellet studies. By using the same reference material, the methods can be normalized and the pelletability of biomaterials can be validated in a new way. This step would develop the research in the field, and the possibility of increased use of biomass towards the use of more renewable resources in pellet production.

  • 192.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Renström, Roger
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Pneumatic dryer as a second step in a two step drying technique2013In: Sixth Nordic Drying Conference NDC 2013, 2013Conference paper (Refereed)
  • 193.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Renström, Roger
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    The Potential of Using Two-Step Drying Techniques for Improving Energy Efficiency and Increasing Drying Capacity in Fuel Pellet Industries2013In: Drying Technology, ISSN 0737-3937, E-ISSN 1532-2300, Vol. 31, no 15, p. 1863-1870Article in journal (Refereed)
    Abstract [en]

    The use of wood fuel pellets has increased worldwide in recent years, and pellet producers conclude that the lack of drying capacity is a barrier to increased production. In this study, we develop a concept of two different dryers called the two-step drying technique. The aim is to show the potential for increasing the drying capacity and improving energy efficiency when introducing a second dryer into the pellet plant. The study is theoretical and based on an industrial packed moving bed dryer. It shows that the drying capacity increased by 22% when a pneumatic second dryer was used.

  • 194.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Technology and Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013). Environmental and Energy Systems.
    Linden, Pär
    Wallenberg Wood Science Centre, Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
    Henriksson, Gunnar
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Compression of Biomass Substances—A Study on Springback Effects and Color Formation in Pellet Manufacture2019In: Applied Science, E-ISSN 2076-3417, Vol. 9, no 20, article id 4302Article in journal (Refereed)
    Abstract [en]

    In order to increase the use of a variated raw material base for pellet production with a maintained density level, knowledge of the biomaterials’ ability to counteract any springback effects is essential. In this study, the springback effects were investigated for single press produced pellets from cellulose, hemicelluloses, pectin, and two woods at different moisture contents. The change in pellet coloring was also tested through a spectrophotometer for both xylan and carboxymethyl cellulose (CMC) pellets. The results show that the density of xylan pellets is much higher than glucomannan, for both green and cured pellets, and that the length of the pellets, as well as springback contribution, differ between the hemicelluloses. The study also presents results showing that both xylan and CMC pellets have a mutually identical spectrum and that the changes in the structure of xylan are not only related to moisture content, but are also pressure-related. The study also postulates that the color difference of the xylan pellets is a result of physical changes in the structure, as opposed to being of a chemical nature.

  • 195.
    Fryklund, Jenny
    Karlstad University, Faculty of Technology and Science.
    Småskalig säsongslagring av solenergi för uppvärmning av bostäder: Simulering av lagerutformning och konsekvensen av adderade uppvärmningsbehov motsvarande en pool och ett atrium2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The sun is a huge energy source with great potential of providing energy to the heating of homes and other buildings in an environmentally sustainable manner. In order to provide buildings with energy from the sun it is necessary to transfer the energy supply over time to when the demand arises. By storing the heat in a seasonal storage, solar energy from the summer can be used in the winter when the demand for heating is greatest.

    Today's existing plants are mainly in Europe and particularly in Germany. These facilities are designed to supply heat demands greater than 400 MWh and covers about 40-50 % of this need which consists of energy for space heating and domestic hot water. How much of the heat demand that is covered, the solar fraction, is partly due to losses from the storage which in turn is connected to the surface area of the storage. The bigger a storage, the smaller the losses because of the decreasing relationship between surface area and storage volume. Looking at the size of the seasonal storages that are currently in operation, the question if seasonal storage is also suitable for installations designed for heat demands smaller than 400 MWh arises.

    Jonas Haglund at the architect office Skanark AB in Karlstad is planning an accommodation of 40 flats and hopes that seasonal stored solar energy can serve as the main energy source for space heating and hot water. In order to make housing more attractive he is considering the idea of adding other features, like a pool and an atrium, that also require heating but with lower temperature requirements. Haglund would like to investigate whether the efficiency of the solar collector increases when the extra energy demands are added and if the energy cost, for those demands, in this way can be reduced.

    The purpose of this study is to investigate the possibility of covering a large fraction of a small-scale annual heat demand corresponding to about 40 newly built apartments. The study shall present the solar fractions that can be achieved with different storage concepts when storage size and collector area is varied. The study will also answer how the solar fraction will change if a heating demand with lower temperature requirements and varied character is added to the basic domestic heating and if the added energy demand to some extent can be free. These questions are answered by calculations and simulations with the simulation software COMSOL Multiphysics.

    The results show that it is possible to obtain solar fractions above 80% with sufficient collector area. Suitable storage volume varies depending on the specific storage concept. Simulations of seasonal storage in a tank show that a storage volume of 13 m3/MWh is an appropriate size, while the corresponding figure for duct storage in clay is 20 m3/MWh. An added heating demand of low temperature character increases the efficiency of the solar panels and creates, so called, free energy.

  • 196.
    Fryksenius, Ann
    Karlstad University, Faculty of Technology and Science.
    Effektivisering av fördimentering med hjälp av interna strömmar på Skoghalls bruk, Stora Enso2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 197.
    Fryksenius, Johan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Lagning av slaggskänkar i stålindustrier med MIG/MAG- svetsning och Lindbergsmetoden: En fördjupning och jämförelse i tidsåtgång, energianvändning samt energikostnader mellan MIG/MAG-svetsning och Lindbergsmetoden2017Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Sweden stands today with major challenges to reduce the impact on the climate and the environment. A big part of managing to achieve a sustainable society is to reduce energy consumption. Today the industry accounts for one third of Sweden's energy consumption and in the steel industry, there is great potential to make energy savings.

    There are around hundred steel mills in Sweden and these produce a large amount of steel every year. In the manufacturing process, when the steel is tapped into ladles there is formed at thin layer of unwanted residue on the top of the ladle. This product is called slag. The residue product that is not used is scraped to a slag ladle. When this process is performed, follows steel of finer quality in to the ladle. The finer the quality of the steel burns a hole in the slag ladles that can be about 300-500 millimetres in diameter.

    With the current technology, are the slag ladles repaired using MIG/MAG welding. This method is well established in the steel industries. The method is a rather slow process of welding, the techniques must sit and the repairing takes about five weeks. The process is both inefficient, energy- intensive and expensive. Which also results in a big impact on the climate and the environment.

    Thomas Lindberg is an inventor who had an idea. All repair and splicing of railway track using a method called Termite welding. The method applies a composition of iron and aluminium powder is heated and forms a volume of molten metal in a short time. Thomas thought that this method would be well suited to the repair slag ladles in the steel industries. The method works well and there have been thoughts that the method has significant advantages over MIG/MAG welding.

    Therefore, these two methods were compared regarding of the time consumption, energy consumption and energy costs.

    To analyze the methods there were interviews including welding techniques and the calculations was based on a general steel mill in Sweden.

    The study showed that the Lindberg method was is a good alternative to MIG/MAG welding with better characteristics regarding; time consumption, energy consumption and energy costs. 

  • 198.
    Gadde, Lena
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Leo, Madeleine
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Den Konfliktfyllda Arbetsgruppen: En Studie av Kännetecken och Orsaker2009Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Denna uppsats försöker besvara vad som kännetecknar och orsakar konflikter i en arbetsgrupp. Området var omfattande avseende litteraturen och vi har valt att ta fram de bitar som var vanligast på den arbetsplats vi besökte. Uppsatsen är en kvalitativ undersökning.

    Undersökningen är genomförd på ett callcenter i Närke och vi djupintervjuade sex kommunikatörer för att få en bra bild av vad som dels orsakat men också kännetecknat konflikter i deras arbetsgrupp. Det framkom att det fanns flera orsaker. Bland annat togs det upp att kommunikationen brast mellan kollegorna och ledningen, en del skapade egna regler och rutiner för hur man skulle utföra arbetet vilket ledde till förbistringar hos andra, vidare påtalades att det var svårt att ha ett informellt ledarskap och ingen formell i arbetsgruppen.

    Det fanns flera kännetecken på konflikter också. Exempelvis fanns det grupperingar bland kollegorna, det bland annat hade förekommit mobbning, och det fanns en konflikträdsla bland de anställda som hindrade dem att agera ibland.

    Resultatet av denna undersökning är således att det inte finns en orsak eller ett kännetecken, utan det är flera. Vi har redovisat de tydligaste svaren och kommit fram till att makt är en överordnad orsak till konflikter i arbetsgruppen. Ett exempel på detta var att vissa personer ville ha mer makt och inflyttande över sina kollegor.

    Uppsatsen inleds med en teoretisk genomgång av litteratur i ämnet. Därefter fortsätter vi med metoddelen, där vi berättar hur vi gått tillväga vid intervjuerna samt hur vi bearbetat intervjumaterialet inför analyserandet. Därefter följer ett kapitel med resultat och analys av de svar vi fick. Vi avrundar uppsatsen med att besvara våra inledande frågeställningar.

  • 199.
    Ganic, Adrian
    Karlstad University.
    Modellering och simulering av teleskopläktare2015Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    The thesis work has been performed on behalf of Egas Sport AS, a company based in Norway, with activities geared towards various types of sports equipment. The task was to create a parametric 3D model of a telescopic bleacher with 3D CAD programs as well as to perform finite element analyzes (FEM) for determining stresses in the construction and to calculate the critical load for elastic instability (buckling). The telescopic bleacher contains several different components, some of which are as follows:

    • Front panel: Conceals the supporting steel frame and prevents possible personal injury in case of climbing.

    • Diagonal link: A link that prevents the structure from swaying sideways during use

    • Steel pillars: Taking up pressure forces from the deck.

    The results from the FEM calculations showed that no part of the construction was at risk of failure, either because the stress levels were too high, or that critical load for buckling was achieved.

  • 200.
    Garcia Lawson, David
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Produktion av näringspellets med varierad mekanisk kraft och ligninhalt: Utvärdering av pelletsegenskaper och energianvändning2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Continued increase in carbon dioxide emissions lead the ecosystems towards rapid, dangerous and irreversible climate change. The Swedish forest industry is an important operator to satisfy the future demand of renewable bio products to reduce the use of fossil fuels. The increase in production means increased pressure on the Swedish forests. Society, government, companies and individuals have a responsibility to secure that the harvesting of forests remains sustainable.

    The wastewater treatment plants in the pulp and paper industry produce a large proportion of biomass, in form of bio and fiber sludge. Bio and fiber sludge contains nutrients that can be returned to the forest. The upgrade of biomass to pyro-char has proven properties that improve the fertility of the forest, primarily by increasing the soil's pH value. Pyro-char improves the retention of nutrients in the soil by cation adsorption, which affects the trees and plant growth. The composition of the soil changes as pyro-char is added, and the change in composition affects the biodiversity in ecosystems. The biofuel ash extracted from the heating boilers in the paper industry contains basic cations and alkaline pH, which counteracts acidification in forest land.

    The disadvantage of biomass is the high bulk density, which affects the logistics of transport and storage. There are methods for solving the problems in logistics, for example compression. Compression is a well-proven method for upgrading the biomass to pellets and improving the physical properties of the biomass. The conversion of biomass into pellets increases the density, mechanical strength and the moisture absorption capacity decreases. Pelletizing biomass results in a homogeneous product can be created and delivered as pellets.

    The purpose of this study is to increase the knowledge on how lignin as an additive, and how mechanical force affects the physical properties of the nutritional pellets. The production of nutrition pellets consists of two stages, a preliminary investigation and a test matrix. The purpose of the preliminary study is to acquire guideline values ​​and provide a basis for the experimental matrix. The experimental matrix is ​​a continued study of how lignin content and pressure affect the physical properties of the nutrition pellet. The lignin content that was analyzed was 5-20 % with mechanical force that varied between 5, 10 and 15 kN. The nutritional pellets are evaluated based on the properties density, hardness, pH, moisture absorption capacity and energy use.

    The single-pelletizer press, located at Karlstad University, was used to pelletize the different mixtures. The pellet properties were evaluated at the laboratory at Karlstad University.

    The result shows that the test series with a pressure of 15 kN and the lignin content of 20% resulted in the highest density, hardness, moisture absorption capacity and the second highest energy consumption. Depending on the mechanical force and lignin content used, the parameters varied as follows.

    • The density varies between 843.5 – 1,054 kg/m3
    • The hardness ranged between <1 and 3.7 kg
    • The moisture content of the pellets varied between 8.7% and 9.2% after 96 hours
    • The pH-value varied between 8.7-9.58 after 24 hours and decreased between 2- 4.9 % after 48 hours
    • The energy consumption varies between 105.5-129.5 J

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