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  • 251.
    Hedh, André
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Playano: Konceptutvecklingsprojekt av en trådlös och energialstrande klaviatur2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report contains a product and concept development project carried out by André Hedh as a Bachelor Thesis at Karlstad University’s faculty of Health, Nature and Engineering Science in the Innovation and Design Engineering Programme.

    The project was carried out for design agency People People with Per Brickstad as task manager.

    Prior to this project, People People had, through its subsidiary - People Products, developed The Transparent Speaker. Their wish was to develop more products for music lovers and musicians.

    The product developed in this project was a keyboard, which was one of three products in a family that aimed to make it easier, more fun and more social to learn and play the piano.

    The keyboard was designed to maintain the genuine feeling of a classic acoustic piano, but with modern technology for wireless communication.

    The work dealt with studies and investigations in what distinguish the feel of the grand piano action, plus creativity and engineering methods to simulate this feel.

    The project also aimed to incorporate an Energy-Harvesting system into the piano’s mechanism, to eliminate external power supply.

    The kinetic energy from the keystroke was converted to electricity and used to set up a wireless connection over Bluetooth Low Energy with an external application that could translate MIDI data into sound.

    A proof-of-concept was developed through a full-scale prototype of the key mechanism, containing a conceptual solution for the mechanism including all electronics and key features of the final product’s design. 

  • 252.
    Hedqvist, Fredric
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Automatisering av pressprocedur2016Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report shows the thesis work done at engineering office Camatec Industriteknik AB, on behalf of RZ ZamPart AB. ZamPart is located in Karlstad and manufacture products to companies in the car, defense and engineering industries. ZamPart presses articles to SAAB in Karlskoga. Today the press station is operated manually by the staff. The work is repetitive and demanding on the staff.ZamPart has given the assignment to Camatec to develop a working concept that assist the staff by automating parts of the operations. The concept need to handle 100 operations per hour, be able to place the press articles with enough precision not to harm the articles. It needs to lift the cylindrical articles in and outside with a load of 2,8 kg. The concept should be easy to work beside and easy to change the work operations on the press and on the concept between the press articles. During operation, it should be easy to access tools and press articles. This provides improved ergonomics and work.In the concept that were developed, staff manually inspect and loads the feeding table that consists of plastic chains. An industrial robot picks the press articles from the feeding chain and controls the work around the press. When the article is pressed the robot places it on the conveyor belt that leads to a picking table. There, the staff manually picks the press articles into the factory baskets on a pallet.

  • 253.
    Hekkala, Madeleine
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Reduktion av växthusgasutsläpp och återvinning av spillvärme inom kemisk processindustri: Alternativa systemlösningar för värme-, ång- och elproduktion vid Akzo Nobel Adhesives AB2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Combustion of fossil fuels increases the concentration of greenhouse gases in the atmosphere, and the natural greenhouse effect of the Earth is enhanced. The European Union has set energy and climate targets to reduce greenhouse gas emissions by 80-95% compared with 1990. 

    At Akzo Nobel Adhesives AB in Kristinehamn, steam is now being used for production processes and for heating water and factory premises. The steam requirement is partially met with oil-fired boilers, which annually results in 3000 tons of CO2. On the site, energy-rich waste heat flows are also found in form of excess steam, high-temperature flue gases and residual water from cooling processes. The AkzoNobel Group itself has an internal, international goal to become carbon neutral and use 100% renewable energy by 2050. The use of fossil fuels is something that has to be phased out to achieve this goal. The use of fossil fuel in combination with the large amount of waste heat released into the environment are two factors that require action if the Group is also to help and contribute to achieving the European Union's energy and climate goals. 

    The purpose of this thesis was therefore to review the steam diagram and chart energy-rich waste heat flows at the Kristinehamn plant to investigate alternative solutions that would replace the steam production from the fossilized boilers in whole or in part. The actions investigated are alternative steam production, alternative methods of heating and electricity generation in situ. Alternative system solutions have been studied individually and in selected combinations based on a decision tree. System solutions were assessed based on cost reduction, reduced amount of CO2-emissions and share of recovered waste heat. 

    The system solution that results in the largest total cost reduction (4.8 MSEK) is to switch to a biofueled boiler, to meet the heat demand with upgraded residual water via heat pump, and to produce electricity with surplus steam and extra steam produced through a condensing turbine. The same system solution but with any fuel to the boiler (oil or wood powder) is also the one that performs best with regard to the amount of recovered waste heat (25.7 GWh). The system solution with the largest total reduction of CO2-emissions (6150 tons) is to switch to wood powdered boilers, to meet the heat demand with district heating, and to produce electricity with excess steam and additional produced steam through a condensing turbine. However, this system solution becomes more expensive on an annual basis. All these three systems perform even better with integrated ORC. 

    Based on the results, it can be concluded that when measures are taken to recover waste heat, the annual cost reduction increases. A conclusion that can also be drawn from this study is that individual solutions are not always better from an energy-flow perspective. All combinations that are technically possible are also not suitable. In conclusion, there are good opportunities to reduce annual costs, reduce annual CO2 emissions and recover available waste heat energy with different technologies.

  • 254.
    Hellberg, Julia
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Utveckling av dörrstängningsanordning: med fokus på en nytänkande och estetiskt tilltalande design2016Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report is a part of the course MSGC17 for Bachelor in Mechanical Engineering. The course were held at the University of Karlstad. The project was performed on behalf of a company that manufactures doors. The purpose of the project was to develope a door closing device. The closing device were supposed to be innovative and have an aesthetically pleasing design, since this was lacking in current products. The work resulted in a design proposal for a doorcloser which is recessed in the door leaf. This type of mounting results in a aesthetically pleasing design since it is not visible at all. This result were achieved through the use of the product development process according to Johannesson et al. (2013). This process included a plan for the project, prestudy, concept generation, evaluation and selection, layout design and prototyping. The prestudy was an important part of the project. This part led to many innovative ideas that could be brought into the concept generation phase. The final design proposal was inspired by a cord retractor from a vacuum cleaner. When the design proposal was developed a prototype were made as a final part of the project. The task of the prototype was to show the function of the structure in a simple way. The conclusion to be drawn is that the generated construction meets the requirements of the specification. Further work after this project will be to produce a prototype in full scale for different types of tests.

  • 255.
    Hellberg, Max
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Optimization of diagonal stiffeners to handle wind pressures on silos2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this report the focus is set on how to optimize the support structure of a silo and in particular, the stiffeners and fastener. The main force of the silo comes from the wind pressures. The design is subjected to the Swedish and European standards SS-EN 199-1-4:2005, 1993-1-1:2005 and 1990. Much of the design work was put on determining the pressure for buckling of the stiffener and to determine the shear force on the bolts. Calculations on how the silo was affected by wind pressure was also calculated by the use of the SS-EN standard. The silo that is analyzed started with a design that was largely conservative designed, which is making it hard for the company constructing the silo to compete on the European market. The focus of the report is to minimize the material needed for the diagonal stiffeners between the columns. This because the diagonal stiffeners made up 80\% of the total stiffener length. The idea is to change the U-shaped beams with the dimensions 50x30x2 to L-shaped beams with the dimensions 25x25x2. A plate that earlier connected the stiffeners was removed and replaced with a circular plate that were put at the place where the diagonal stiffeners intersected each other. This was possible since the stiffeners were put in a configuration where they would not hit each other but instead go past one another. The new ring was placed in the gap between the stiffener. The simulation in Abaqus was performed with the following wind pressures:\\1. Roof: 0,78 MPa.\\2. Shell: 0,5 MPa.\\3. Columns: 0,8 MPa.\\The allowed limiting pressures on the stiffener based on the wind pressures were:\\1. Allowed pressure around bolt: 692 MPa.\\2. Allowed pressure to prevent buckling: 183 MPa.\\3. Allowed pulling pressure on stiffener: 273,6 MPa. \\By color scale it could be determined that the silo would remain stable. The areas that exceeded the allowed values in Abaqus were considered singularities and could be neglected.

    From a manufacturing point of view, the proposed change was possible if two machine tools were used. One for the original stiffeners and one for the changed diagonal stiffener. All changes follows the European standard and resulted in a 24\% cost reduction when counting in the cost of all the stiffeners. The optimized diagonal L-shaped stiffeners has resulted in a decrease in price by 36,3\% while the unchanged stiffeners have increased in price by 26,1\% due to the adding of an additional machine.

  • 256.
    Hernvall Jonsson, Erik
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Konceptuell modell för ljusförsörjning i skyddsrum vid strömbortfall2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In a parallel with the potential reestablishment of new production of swedish shelters, an awareness of a great potential of modernisation on swedish shelters has occurred. Sweden is in the process of a new potential production of modern swedish shelters, but there is a long process before all the technical details has been updated. This is a bachelor thesis for a degree in mechanical engineering at Karlstad university. The object of this report is to show how a shelter can be best supplied with light during a period when normal power fail.

    The recommendation of the report is to use wall mounted LED units that are supplied from an electric generator, operated manually by hand. This model has been developed based on swedish regulations for shelters and includes recommendations from these regulations. The concept could also be considered as a necessity for protectetive cautions during realistic crise circumstances.

    This project was initially a construction developing-oriented project for a specific product that aimed for higher security and functionality in shelters, but resulted in a koncept for light. The method has therefore followed processes for product developing.

  • 257.
    Hideblad, Daniel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Equipment for Accelerated Vibration Testing2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The increasing complexity with the decrease in size of EEE – components (Electronic, electric and electromagnetic) raises the question on how higher energy frequencies will affect the components and their continuous development. The most common vibration testing equipment currently in use within the automotive industry and SCANIA CV AB are the electrodynamic shaker (ED system). This thesis covers the characteristics of different vibration testing equipment while analysing their strengths and weaknesses, not only for the automotive industry but also including equipment more commonly handled within the aero and space industry. The project aims to find a complement for the ED system and study the possibility for its replacement in the automotive industry.In particular, experiments are carried out and documented on a so-called “Repeatable shaker system” (RS system) for the purpose to get a better understanding on the functions of the equipment and its overall differences compared to the electrodynamic system when it comes to random vibration testing.It became clear that complementing or replacing the ED system is difficult and that the RS system work fundamentally different in comparison. Accordingly, the RS system is not a potential replacement for our purpose and it cannot perform at the same level of precision but instead is able to achieve higher energy frequencies overall, making it still ideal for its intended purposes, but not as a replacement of the ED system.

  • 258.
    Hinders, Fredrik
    Karlstad University, Faculty of Technology and Science.
    Konceptförslag för detaljhantering i en svetsrobotcell2009Student thesis
    Abstract [en]

    Abstract

    At the plant of Outokumpu Stainless Tubular Products AB in Molkom a wide range of butt weld fittings are produced. These are aimed mainly for the process industries and one of the products are ninety degree bend elbows in various dimensions. The elbows are made from stainless sheet metal and when formed to a tube they need to be welded along its inner radius. This is made by a pick and place type industrial robot working in a closed compartment. The assignment given by Outokumpu aims to investigate and suggest a new concept for a more reliable manufacturing process within the work cell.

     

    The cell consists of five main areas chronologically listed as passed by the elbow:

    ·          Automated, vibrating conveyor.·          Fixture with the purpose to serve the robot with one elbow at a time, placed in the correct position.·          Industrial robot to pick up the elbow and drag it along the welding head.·          TIG inverter with a stationary welding head·          A hydraulic press with a template of the final shape of the elbow corrects flaws. Almost every problem in the cell and defects on the products coming out of it can be traced back to the fixture and in some cases also to the robots pick up tooling. The focus of the task was therefore put mainly on those two areas. As the work proceeded Outokumpu chose to develop a new tool for the robot themselves which they did with good results. I chose to incorporate it into my study and change focus to the fixture instead.

     

    The problems and possible causes to them were identified and discussed with my tutor:

    • The elbows fall incorrectly into or beside of the fixture. 
      • Fixtures are old and worn down.
      • The elbows path between conveyor and fixture are somewhat out of control
      • The smaller dimensions have room enough to slip past the fixture.
        • Edges to be welded are to far from each other or badly shaped
    • Commissioning time, some start up steps is more complex then they need to be.
      • Some of the setting possibilities in the working cell are unnecessary and can be fixed instead.
      • The positions of pick up and welding head are not really fixed in the robot software, these are reprogrammed every time elbow size are changed.

    ·          Various errors at weldingo    Robot managed to pick incorrectly placed elbow

     

    Proposals to solve the above specified problems:

    • All parts in contact with the elbows are to be made of harden able steel. A suitable one is C45E which can be casehardened to about 700HV.
    • On the outer edge of the conveyer a support are placed to prevent excessive wear.
    • The fixture is partially redesigned with a support to control the elbows path better.
    • Guide arms with dual purpose are added. First they guide the elbow into the fixture and secondly they turn it to the correct angle towards the robot.
    • Pins are used along with quick lock clamps to obtain faster and easier commissioning.
    • The pick and place tool developed by Outokumpu are used.
  • 259.
    Hobbins, Jennifer
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Holth, Line
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    "Vi är ju ändå en del av hela samhället": Solakoop - en fallstudie av ett socialt företag2008Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [en]

    Within working life, large-scale changes have taken place which have implied rougher conditions for everyone, particularly for those that are excluded from the labour market for differrent reasons. This paper is a case study of a social enterprise run by people with a mental health handicap. The aim of this study is to gain understanding and knowledge about what the social enterprise has meant for the co-operative’s participants, for their situations in life in general and, more specific, their relationship to working life.

    We have made a qualitative study based on in-depth interviews with six participants and the two guiding mentors of the business. The conclusions of our study are based on analyses of the interviews. The first, and possibly the most important, conclusion we have drawn is that participating in Solakoop has given the co-operators a higher level of self-esteem, power of initiative and sense of responsibility. Dependence on sickness benefits and/or allowances,

    however, produces large negative consequences for individuals.

    Furthermore we have seen that the latent by-products of work, as described by Jahoda, are of particular importance for individuals with mental health handicaps and that all of them are

    accomplished in the social enterprise. We have also come to the conclusion that work in the social enterprise has a rehabilitating effect on the participants’ mental well-being and their

    diseases. Finally we have drawn the conclusion that working in the social enterprise has brought the co-operators closer to the open labour market.

  • 260.
    Hoikka, Arvid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Strength simulations of tension bars for heavy lifting2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Proplate, a world leading company, is expert on volume-based cutting and machining of both ordinary steel as well as stainless steel. One of Proplate’s mayor products is tension bars, which is a component made to balance high forces and give stability to structures such as cranes, buildings, bridges and much more. Proplate builds their tension bars in different high strength steel materials, purchased from SSAB, and sells them worldwide. Proplate would like to market themselves better and wishes to produce a catalogue for the maximum load that can be applied to their tension bars, as competitors Pretec and Macalloy, already have for their tension bars. The purpose of the project has been to investigate the tension bars and the maximum load they can withstand before failure. The tension bars have been modeled in the CAD-program Creo Parametric, and then sent to the finite element method program ABAQUS to analyze their structural strength. Three different types of tension bars, and a fourth tension bar (called the walnut-strap) used as a connecting element between some of the tension bars, were investigated. They were modeled with sprints, to hold several tension bars together, and with a construction called loader, to simplify the model load application step. The three different types of tension bars have been analyzed as individual and also when connected to other tension bars. Some tension bars could be directly connected to each other with sprints, and some used the walnut-strap to connect other tension bars to each other. The project was limited to fatigue analyses, which is an important factor to control. This could instead be a great continuation of the project. The results from the strength analyses show that the stress is higher at the surfaces around the hole at the end of each tension bar, and the maximum load the tension bars can withstand depends on this area. The length, thickness and orientation of the tension bar has been varied, and the maximum load that each model can withstand has been listed. The length and direction of the tension bars did not influence the result for singular tension bars, but the thickness did. Both the length and the thickness of the tension bars did influence the result when multiple tension bars where connected to each other. Tables have been derived which shows the absolute maximum load that the tension bars can withstand. Proplate can use the tables in their catalogue, and they can also put a safety factor on the models to make them safer. Another part of the study was to investigate advantages and disadvantages with if the sprints, the connecting element between the tension bars, were replaced with screws instead. The result describes the yield strength needed for the screws and how the structures would behave compared to the current structure. A larger investigation into the effect of using screws may be one way to continue the work after this project, together with other investigations of, for instance, the use of compression bars.

  • 261.
    Holm, Magnus
    et al.
    Högskolan i Skövde.
    Doverborn, Josefin
    Högskolan i Skövde.
    Ng, Amos
    Högskolan i Skövde.
    De Vin, Leo
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Optimisation of Operation Sequences in Flexible Manufacturing Cells Using Virtual Manufacturing Tools2009In: FAIM 2009 Proceedings of the 19 th International Conference on Flexible Automation and Intelligent Manufacturing / [ed] Nabhani, Farhad, Middlesbrough: University of Teesside , 2009, p. 1317-1324Conference paper (Refereed)
  • 262.
    Holmgren, Albin
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Wagell, Oskar
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Evaluering och effektivisering av en manuell produktion: En fallstudie över hur The Toyota Production System, Lean Production & Total Quality Management filosofierna kan tolkas och appliceras för att effektivisera produkt– och materialflödet i ett producerande företag2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Flexit AB is Norway’s largest manufacturer and supplier of air handling units and central vacuum. The company is growing and has now expanded over the borders of Norway with the vision to become the largest manufacturer and supplier in the Nordic region and continuously grow by 10 % a year. Flexit has about 200 employees and a turnover of approximately 550 millions NOK a year. Thanks to this expansion, an increase in market shares has occurred, leading to an increasing demand for Flexit’s products.Today’s production of Professional units, the largest model of Flexit’s products, can not meet the forecasted demand. To be able to meet the new demand, Flexit must increase the capacity of the production of Professional units and streamline the flow of materials within the factory.

    The thesis adopted a mixed metodology and decided that a case study was the most relevant research design. Data were collected through semi-structured- and context interviews, observations and time studies. Data were analyzed using an analytical framework inspired from content analysis.

    The aim of this thesis was to present a number of improvement proposals (IP) which will help Flexit achieve a more efficient material flow and an increased capacity of the production of Professional units. The inspiration for these IP’s is based on the ideas and tools presented within the management philosophies of the Toyota Production System, Lean Production and Total Quality Management.

    To be able to establish these IP’ls the thesis were structured in three different parts. In this educational way, the reader is lead through the results and conclusions of the three parts, which is generated through the thesis. Part 1 dealt with Value stream mapping (VSM), were the goal was to identify waste, improve the efficiency of the assembly steps and to even out the production. In the future state of the VSM the process –and staff occupancy was evened out, limiting assembly processes gets an increased capacity and the implementation of a Telfer reduce throughput time and increases the safety for the workers. The future state is expected to increase Flexits maximum production capacity with up to 77 %. In part 2, Systematic Layout Planning (SLP) is used to streamline the flow of material and to minimize the transports within the factory. The result from the VSM in part 1 is included in part 2 and affects the outcome of SLP. With spaghetti diagrams and SLP the thesis identifies transport –and moment waste. Using SLP, the thesis generated a new factory layout, which streamlines the flow of material and reduces the unnecessary movements within Flexit’s factory by 75 %. In part 3, a summary of the results from the first two parts is presented. If the IP’s presented in this thesis is implemented by Flexit, they can save up to two millions (Kr) between 2017-25. Part 3 also presents a basis for how Flexit can establish a continuous improvement (CI) program. This program is established through the implementation of Kaizen and 5s, which will help Flexit develop and improve the IP’s and help them towards continued development.

    With the development of the CI program, a theoretical gap between organizational learning, innovation and CI was identified. By establishing a CI program in an organization, where an open and active organizational culture encourages innovation, an organizational learning will emerge.

  • 263.
    Holmén, Andreas
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Konceptrealisering av tappvarmvattenproducerande sol- och luftvärmepump: Framtagning av funktionsprototyp med syftet att tilltala investerare eller samarbetspartner2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This project has been a degree project for the Bachelor of Science programme in Innovation and Design at Karlstad University. The degree project extends 22, 5 ECTS credits and has been carried out by Andreas Holmén. The academic supervisor from Karlstad University was industrial designer and lecturer Lennart Wihk and the examiner was Professor Fredrik Thuvander.

    The degree project was part of a bigger project involving five other students. The project was an industrial cooperation between Karlstad University, Glava energy center and Värmestugan AB.

    The project is built around an idea about being able to improve the energy efficiency of the heating of domestic water by combining solar heating and heat pump technology. The initial phase of the project was carried out with the whole project group together, when the group agreed on a main concept each member of the group focused on his/her specific task.

    This specific degree project set out to find out the requirements suitable for a functional prototype meant to accost an investor or a partner company. But also in what way these requirements could be reached within the project’s timeframe.

    The task was solved by making a research that was compiled by using a functional analysis and a semantic analysis resulting in a requirement specification. Later the information that emerged through the research was used to come up with ideas and design documents for the prototype.

    The construction of the prototype took up the largest part of this project, since it was the group’s main objective to produce a functional prototype within the projects timeframe.

    The final result of this project was the functional prototype of a air-air heat pump aided by the sun, but also the knowledge that was accumulated during the research phase and the making of the prototype.

  • 264.
    Hugoh, Albin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Modeling of a Gear Test Rig: An Investigation of Static Loads and Dynamic Excitation of Vibrations2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today the automotive industry is going through big changes and facing many new challenges due to the transformation to a sustainable transport solution in combination with tougher legal demands. Gears have been around for a long time and it is one of the most efficient ways of transferring rotary motion from one shaft to another. Transmissions is a key factor in order to transfer the rotary motion from the engine to the wheels. Both traditional combustion engines and electric powered vehicles needs a transmission with gears. The continuously increasing demands on efficiency, noise and durability requires increased knowledge about gears, especially about gear dynamics and how vibrations are excited and transferred to the gearbox for different mesh frequencies. In this report, a theoretical background about gears is presented as well as the mechanisms behind the excitation of vibrations. The goal with this master thesis has been to create a validated model of a gear test rig. For the static validation, two types of gears have been used in the test gearbox. The gears in question are FZG standardized type-A gears and type-C gears. The model includes gears, shafts, bearings and housings. This model has been used for simulating static torque fluctuations as well as dynamic excitation of vibrations that is transferred to the housings, both at constant speed and with continuously increasing speed. In the dynamic analysis, only type-C gears have been used. To validate the model, vibrations have been measured on a FZG gear test rig using accelerometers and tachometer. For the static validation, torque has been measured while running the test rig at 5 rpm. The results show that it is possible to get the load clutch in the model to behave as in the test rig. It also shows that the model can register the static torque fluctuations similar to the fluctuations in the test rig. The type-C gears are better suited for the simulations and gives a better result than the type-A gears. For the type-A gears there are some numerical problems related to tip contact during meshing. The investigation of the tooth contact pressure pattern shows a good correlation between the simulations and the used type-C gear. The patterns have the same shape on the tooth flank which indicates that the contact between the teeth behave similar in the model and the test rig. For the validation of the dynamic behaviour, the gear mesh overtones have been investigated, both at constant velocity and with continuously increasing velocity. For the simulations, there are some issues related to the FEprobes placed on the gearboxes so instead the data from the inner bearings in the model have been used for the validation. The analysis of the dynamic simulations shows that it is possible to identify the tooth mesh overtones but the resonance peaks are less amplified compared to the measurements from the test rig. For the simulations with constant velocity the overtone trend correlates well with the experimental data at high speeds but at lower speed there is an amplitude peak for the firstovertone that doesn’t correlates with the measurements. As a conclusion, the model has beenstatically validated with good results while for the dynamic validation, there is still some aspects that need to be improved in order to get a good correlation between the simulations and the measurements from the test rig. Improvements suggested is to run the simulation with continuously increasing speed using more time steps in order to get more data points for the rpm spectra. It is also suggested to perform an impact hammer modal testing on the test rig in order to get a better understanding of the damping in the system.

  • 265.
    Huldén Bergström, Evelina
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Working Life Science.
    Andersson, Rebecka
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Working Life Science.
    Den psykosociala arbetsmiljöns påverkan på motivationen: En kvalitativ studie av medarbetare på Myndigheten för Samhällsskydd och Beredskap2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med undersökningen är att få förståelse för faktorer som påverkar motivationen hos personalen på MSB (Myndigheten för Samhällsskydd och Beredskap). Undersökningen belyser dels den psykosociala arbetsmiljöns påverkan och dels ledningens betydelse för de anställdas motivation. I teoriavsnittet behandlas tre olika block: Motivation, Psykosocial arbetsmiljö och slutligen Management. Dessa tre block ligger således till grund för undersökningen och själva uppsatsen. För att få en djupare förståelse om ämnet har en kvalitativ metod valts, med intervju som datainsamlingsmetod. Studiens urval består av åtta medarbetare på MSB.

     

    Analysen och resultatet presenterar vårt datamaterial med hjälp av citat från våra intervjuutskrifter. Avsnittet redogör för de anställdas arbetskrav och egenkontroll, vikten av utvecklande arbetsuppgifter för motivationen, vikten av feedback och uppskattning i arbetet, själva arbetet som motivationsfaktor, möjligheten till delaktighet i planering och beslut, behovet av en kommunikativ och synlig ledning, samt relationer på arbetsplatsen.  I den sammanfattade diskussionen redogör vi för undersökningens slutsatser där vi konstaterar att den psykosociala arbetsmiljön har betydelse för respondenterna på MSB, även om sättet den har betydelse på skiljer sig åt mellan medarbetarna. Det konstateras att de anställda har ett, enligt krav- och kontrollmodellen, ”aktivt arbete” och att det har positiv effekt på motivationen. Arbetsuppgifterna beskrivs som den viktigaste motivationsfaktorn och möjligheten att utvecklas i arbetet genom feedback är i sig en egen faktor.  Medbestämmande visar sig vara en viktig del, det är viktigt att ha möjlighet att påverka sin egen arbetssituation. Slutligen spelar även samarbetsformerna och goda relationer på arbetsplatsen en betydande roll för de anställdas motivation; de beskrivs som näst viktigast. Ledningen har förhållandevis stor betydelse för de anställdas motivation, till viss del beror det dock på i vilket led i ledningen det syftas till, då hierarkin kan sträcka sig högt upp i verksamheten. Högre upp i organisationen finns en gemensam tanke hos respondenterna om att ledningen bör vara synlig och ha en förståelse för de anställdas arbete. Detta anser intervjupersonerna ger motivation i arbetet. Slutligen förs en avslutande diskussion som behandlar utvalda delar i undersökningens slutsatser, studiens styrkor och svagheter, samt förslag på fortsatt forskning i ämnet. 

  • 266.
    Hurley, Daniel
    et al.
    Karlstad University, Faculty of Technology and Science.
    Johansson, Carl
    Karlstad University, Faculty of Technology and Science.
    Konstruktion av snabbkoppling för elektropolering.2010Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 267. Huss, Niclas
    Analysis of headbox structural strength: OptiFlo II TIS 22002019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Valmet is a world leading supplier of tissue machines. In the tissue industry the demand on the machines is high to be able to produce the finest paper for use in products such as toilet paper and napkins. The machine components need to perform to be able to produce a product of consistent quality. Many different properties of the tissue can be evaluated through manipulation of the fibre content. Layers of cellulose are added into the process through a headbox, which acts as nozzle which distributes the fibres and water along the machine width. The tissue machines can be around 6 metres wide which put high demands on structural rigidity of the machine components to be able to maintain a uniform product along the machine width. Crucial parts are calculated prior to manufacturing to make sure they fulfil stress and rigidity criteria.

    This thesis covers the development of such a computational model of a headbox. The aim was to create a model which will be accurate in terms of deflection but also fast to calculate using ANSYS Workbench software.

    Many simplifications were made in the model to speed up solving time such as:

    • Removal of non-structural parts

    • Mirror symmetry

    • Material manipulation to replace perforated structurally important itemsAlso contact formulations were showing a large effect on accuracy and solution time in the model.With applied simplifications the solver time was decreased by over 73% compared to the initial model.

    The computational model was used in the thesis to evaluate the current configuration of the transverse welds in the headbox when exposed to static load. The load was applied by internal pressure. An evaluation was desirable following a material change from austenitic stainless steel SS2343 to the LDX2101 of duplex grade. LDX2101 which have a significantly higher yield stress of near 500 MPa compared to 250 MPa for SS2343.For static evaluation the welds showed low stresses in welds throughout the headbox. This leaves room to possible optimization of weld applications by reduction to least recommended throat measure of 3mm. This reduction result in quicker manufacturing time and thereby lower manufacturing costs. Static calculations show possible reductions of 66% in application time.

  • 268.
    Huzell, Henrietta
    Karlstad University, Division for Business and Economics.
    Management och motstånd: Offentlig sektor i omvandling - en fallstudie2005Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    This case study focuses on the intentions of public sector transformation. In particular, on a Swedish public authority, the National Rail Administration (NRA) this is studied and analysed. As in other parts of the Swedish public sector, the management of this authority is planning and executing ‘marketisation’ reforms. Parts of NRA’s monopoly are to be ended and to be guided by the market. The aim of the study is to examine how conflicts between management and employees are shaped according to the changes taking place. Firstly, the study assesses how management interprets the new demands put upon the organisation and translates them into action. These actions illustrated as changes from 'monopoly to market' in order to be a legitimate business competitor; from ‘bureaucracy to flexibility’ in order to enhance competence and changing employees' identities from 'technique to tactic' in order to serve the customer properly

    The study then examines the management-driven implementation of these reforms; and how the employees respond to the changes from a resistance perspective. The discussion highlights what happens when the new management-driven organising principles meet the old, technology-oriented principles of employees. This contributes to a deepened understanding of why organisational changes made in the name of ‘market’, ‘flexibility’ and ‘customer’ meet resistance in the public sector. From a resistance perspective the changes are understood as ‘rationalisation’, work intensification’ and increased ‘individual control’, which per se leads to undermining of the traditional safety culture and technical skills. The customer orientation is met with highly ironic attitudes and interpreted as ‘infantilisation’ of the employees.

    The concluding remarks are that conflict and antagonism is ever present in organisations and in this case manifest in three domains, legitimating, restructuring and revaluating, and between management perspective and resistance perspective.

  • 269.
    Hämäläinen, Christian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Produktionsoptimering av en linje för tillverkning av rundknäcke: Barilla, Filipstad2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 270.
    Hörling, Anton
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Formgivning av en papperskorg2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Abstract

    This thesis documents a bachelor’s degree project for the engineering programme in Innovation Technology and Design, spring semester 2018 at Karlstad University. The project has been carried out in accordance with conventional product development process, in an assignment to design a paper bin for SPAZA; a Swedish company that provides elegant products for spa and hotel environments. All products in the assortment are within the SPAZA material and manufacturing specification: laser cut, bent and powder coated stainless steel sheet.

    The purpose of the project is to apply knowledge acquired from the engineering programme and, with a scientific basis, design a paper bin that considers the needs in all the different stages of its life cycle. This without compromising style or aesthetic expression.

    A pre-study identified the needs in manufacturing, shipping, assembly and use by hotel guests and cleaning staff. These needs were then formulated openly as primary and secondary requirements, and together with what had already been specified by the outsourcer, a product specification was formed, which was later used in idea generation.

    Idea generation produced a lot of ideas for forms and functions. These were combined, and together they formed concepts that were developed further in work with models. Recognized methods for screening were then used to determine which concepts that were of value to present to the outsourcer, and during a conceptual meeting a decision was made on which concept to realize.

    A final concept, Concept 4 as it was called, derives from an idea for function about using the sheet metal’s flexing material properties to hold up the bag. The concept meets the needs in the various life cycle stages with a total of 30 out of 31 fulfilled requirements listed in the product specification.

    A CAD model of Concept 4 was sent to CNC Plåt in Västervik for prototype manufacturing. The prototype was evaluated and adjusted in accordance with identified improvements in forms or function, and with a second version of the CAD model having been delivered to the outsourcer, the goal of the assignment was achieved.

    The project is finished, and the paper bin is one step closer to production.

  • 271.
    Hörling, Daniel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Parameter identification of GISSMO damage model for DOCOL 1200M: A study on crash simulation for high strength steel sheet components2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the automotive industry there is a conflict between the need for weight reduction in order to reduce the CO2 emissions and the need for high safety. It has led to the use of high strength steel instead of the traditional lightweight materials. The increased use of high strength steels in combination with that the shortened development time in the automotive industry has led to the need of improved predictions of the actual crash behavior well since a full scale crash test is both expensive and time consuming.The damage model GISSMO is used in such crashworthiness simulations. In the present thesis the high strength steel grade DOCOL 1200M, GISSMO damage model has a number of parameters and curves that defines when necking and failure occurs, those have to be found. GISSMO is a phenomenological damage mechanics model which is based on experiments and does not consider voids and cracks thus it is only reliable to similar load cases as analyzed in the experiments. The different load cases are represented by the triaxiality which is the ratio between the mean stress and the von Mises stress.To find the parameters a number of test specimens were manufactured and tested in uniaxial tension then a FEM model was designed and the force displacement curve achieved from the simulation was mapped to match the experimentally achieved curve. The parameters were changed by the software LS-OPT® in order to increase the match. A metamodel-based optimization was run to find the curves and parameters with feedforward neural-networks and space filling point selection.The result shows that GISSMO has the potential to predict the failure behavior well, when the different specimens are optimized individually the match is good for all cases and when the simulation is examined the necking and localization of deformation is clearly seen. When the specimens are optimized together the match is not as good as the individual match.In order to improve the results more precise force displacement curves from the experiments would be of interest, for example load cells and optical measurments/strain gages could have been used to get the local displacement and the local stress and stress state. To make the model more reliable pure shear tests and compression tests could be used in future work. Running the optimizations for more iterations may also improve the result.

  • 272.
    Ingmarsson, Johan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Mekanisk arm för att assistera vid lindning på trumma2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As a part of a manufacturing process to produce a kind of steel strip there is a need to guide two strips of steel to the correct position on a revolving drum. It is imperative for the following step in the process that the positioning of the strips are precise. The guidance of the steel strips is currently done by hand. 

    The mechanical replacement for the guidance is supposed to operate unattended once the winding process has begun. The aim is that one operator, instead of two as it is done today, will set up the whole machine including the mechanical replacement and then let the winding of the drum be uninterrupted until it is finished. It is important that the winding goes without interruption to reduce the risk of injuries as well as increase productivity. 

    During the thesis work a thorough pre-study was done, mainly by communicating with the operators of the winding machine since there was almost no available literature. The pre-study led to a complete specification of the mechanical replacement as well as a few ideas for concepts. Since several of the concepts were dependent on one another, a chain of concept selections were performed to get the best complete concept possible. The complete concept provided the foundation for the layout construction created in Computer Aided Design (CAD).

    The new construction is mounted so that it can move in the horizontal plane in order to fulfill the requirements of the production. The guidance is made possible using three separate wheels that are adjustable in two directions. The adjustments to the wheels are made possible by the use of electrically controlled cross sliding tables, that also improve ergonomics for the operator. The most important of the wheels is the 'groove' wheel. The main function of the groove wheel is to guide the underside of both strips to the correct position on the drum, it is placed in the groove of the drum hence the name groove wheel.

    The final construction meet all the demands from the initial specification and about half of the optional requirements. Further development of the construction require the FEM analysis to be confirmed and it would also be preferable to produce some sort of prototype to prove the concept of the groove wheel. The prototype is highly important since the groove wheel has a vital role in the product.

  • 273.
    Isaksson, Markus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Genomgång och analys av alternativ utrustning till utmatningsskruvar i stål2017Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report covers a process that has aimed to review and analyze alternate equipment to steel screw feeders with the primary goal to eliminate the risk of metal contamination. The project has been carried out as a Bachelor thesis for the program in mechanical engineering at the faculty of health, science and technology at Karlstad University.

    At present, HEXPOL TPE AB has major issues with the current screw feeders contaminating their product with small metal chips. Their product catalog consist of thermoplastic elastomers with different properties and they are delivered in the form of granules. The screw feeder's purpose in the process is to transport the finished material to the final packaging and provide the opportunity to add talc or silica powder to the material and mix it extensively to prevent lump formation. During operation, wear and tear between the screw and the pipe has been the main reason for the metal chips. In the future HEXPOL TPE AB want to avoid this issue by replacing the current screw feeders.

    In order to address this issue, work began with preliminary studies of materials relevant to the process and of how the manufacturing process worked. Then a situation analysis was made to create a better understanding of the circumstances surrounding the issue, how the current equipment works and the circumstances in which the new equipment will be exposed. Thereupon, all requirements and request HEXPOL TPE AB has were compiled in to a requirement specification. Then, the search for concepts that solve the issue began. All the concepts presented in the project were then thinned out through an elimination matrix during the final phase of the project.

    The best solution found during the project is based on a modification of the current screw feeder. The solution consists of replacing the rotating steel screw inside the steel tube with a modular plastic screw. This screw is made of a hexagonal steel shaft that drives and holds the plastic modules that are threaded on the shaft during assembly.

    The result of this modification is that metal to metal wear between the screw and the tube is prevented. This eliminates the identified cause of metal chips without affecting other important aspects in theory. In order to drive the project further within the current direction, a suitable next step will be to test the new type of screw with the various materials to be transported, in the form of a pilot project.

  • 274.
    Ivarsson, Lars
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Vad betyder kundfokus?: En studie av närhet, kompetens och teknik2005Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This is a dissertation about customer focus. Customer focus is a concept that can be understood in terms of giving the customer what the customer wants. It has been argued that the industrial society has transformed into a service society with the obvious consequence that services nowadays play a leading part, not at least in regard to customer focus. The customer of today is claimed to have lost interest in mass consumption and is much attracted to personalized and unique solutions, something that results in the fact that businesses must create or develop customer focus, i.e. listen to the customer’s wishes, needs, and demands. According to most researchers in this field, “service excellence” is the primary aspect one firm can use in order to successfully compete with other similar firms.

    According to Service Management, customer focus is much about developing a personal relationship between the service provider (employee) and the customer. In order to that, the service provider needs to adjust his or hers behaviour in accordance with the customer. This circumstance has a tendency to lead to a “master-and-servant” relation, in which the service provider must obey the various wishes, needs, and demands any customer may have.

    Most studies on customer focus have been undertaken in the context of low skill service work, but the results have often (implicitly) been generalized to comprise all service work in the whole service sector. As a consequence of this situation, my survey takes on high skill service work (banking and health care). The main purpose of the survey is to examine if the results and analyses, presented from service management apply when the services are not low skill.

    The results from this survey shows that Service Managements heavily emphasis of the personal relationship between employee and customer – in which the service provider in some meaning need to undertake the role of a servant – can be questioned. The results also show that there is a discrepancy between (bank customers’ and patients’) opinion on an abstract comprehensive level and a specific level where various situations and errands are defined. Further, the dissertation shows that the various factors that can be included in the conception of customer focus, need to be examine more carefully. Some factors integrate in a way that makes it difficult to separate them, and one specific factor can in fact hold a variety of essences.

  • 275.
    Iverlund, Hans
    Karlstad University, Faculty of Technology and Science.
    Akustisk kontroll av framtidens kontor: Summit Flexiwall2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The project presented in this report was conducted by Hans Iverlund and was the final thesis of the Study programme in innovation and design engineering at Karlstad University. The project included 22,5 ECTS credits. Parts of the project were carried out in collaboration with Robin Westlund, who also did his final thesis of the Study programme in innovation and design engineering.

    The project was conducted in collaboration with Moelven Eurowand AB, which is a company that manufactures, sells and installs room solutions consisting of wall systems, door portals and some furniture, mainly for offices. Supervisor from Moelven Eurowand AB was Pernilla Irewährn, tutor from Karlstad University was Monica Jakobsson and examiner for the project was Professor Fredrik Thuvander. Moelven Eurowand AB wished to get better insight for how the future office would look and operate, so that they could develop their future products in the right direction. To gain that insight, the project began with extensive research, consisting of literature studies, field studies and interviews with people that work in offices. Parameters that were identified as important for the future of office were the ability of control over the surroundings and the need for acoustical and visual privacy and social interaction with other people. This resulted in a vision for the future that was visualized with a continuously variable dimmer switch that controls the acoustic environment and the visual interaction with other people in the area in which the individual office employee is located. The dimmer switch became the aim for the development of a product that would fit into this vision for the future. The product development was carried out using a list of demands, idea generation and a systematic generation of concepts. The product that was developed was called Summit Flexiwall, and was a flexible panel-wall solution that enabled control of the acoustic environment and the amount of social interaction. The product may serve several different functions in an office environment.

  • 276.
    Jacobsson, Lasse
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Wickberg, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    De Vin, Leo
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    A Realistic Lean Training Environment for the Manufacturing Industry: Karlstad Lean Factory2016Conference paper (Refereed)
    Abstract [en]

    Simulation for training lean manufacturing ranges from simple paper-based or LEGO®-based games to larger scale simulation environments, for instance push car assembly. Whilst such simulations may be suitable for educating students, they are often less suitable for training industry workers. The latter group is more diverse and is more used to intuitive learning than to formal instruction. Thus, it is important that a training environment for this group more realistically represents the work environment; otherwise training transfer will be limited. For this reason, a lean training environment that includes materials processing stations as well as assembly areas was created. The stations exhibit some realistic behaviour such as stochastic breakdowns. Based on a comparison between factory workers and university students, hypotheses for testing in future work are proposed.

  • 277.
    Jadrijevic, Boris
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Analys av en kondenstorktumlares energi- och massbalans samt av möjligheterna för energieffektivisering2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The thesis was conducted in collaboration with Asko Cylinda AB in order to analyze and improve a recently launched condensation dryer from the company. This report has aimed to establish a mass and energy balance over the condenserdryer, where an analysis of balances would to be the basis to find energy saving improvements. The machine’s initial performance was examined in laboratory tests to see how the performance would be affected by an insulating

    material surrounding the dryer. Particular interest was spent in examining how much heat loss could be reduced and how much less electricity that needed to be brought into the dryers electric heater when insulation was used. Another aim of the thesis was to discuss the potential for additional measures that could reduce the machine's energy consumption. With the help of laboratory tests together with heat-­‐ and mass technical calculations, the report shows that a reduction in heat loss by up to 73 % is possible when a insulation made of foam was used. More over, it

    was possible to consume 6 % less electricity when the heating element was controlled by an on / off control in combination with the use of insulation. The report discusses the possibilities for optimizing operation of the fans, the use of other surface materials and the possibility of efficient sealing as further proposals to implement energy saving measures. The results are considered to be applicable

    to the majority of product groups that the manufacturer Asko Cylinda AB produces. 

  • 278.
    Jadrijevic, Boris
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Analys av passiva kylningsmetoder vid tillämpning över en hotspot genom analytiska och numeriska simuleringar: Till vilken grad kan passiva kylningsmetoder tillgodose ett lokalt kylningsbehov i ett marint framdrivningssystem?2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    I ett marint framdrivningssystem byggt av Rolls-Royce Marine i Kristinehamn, kallat POD Propulsion - MermaidTM, kyls systemets yttre delar med förbiströmmande vatten. Det kylande vattnet kompletteras av ett internt luftkylningssystem vilket, till följd av en lägre kylningskapacitet än för det externa vattnet, förorsakar en otillräcklig kylning i den sektor av elmotorns stator vars periferi kyls av kylluftsströmmen. En andel av statorn är således enbart luftkyld vilket medför att den axiella temperaturen i denna sektor uppnår ett lokalt maximum, kallad ”hotspot”, vilken är högre än för resten av elmotorns stator.

    Avsaknaden av en tangentiellt uniform temperatur i statorn medför begränsningar vid dimensionering av framdrivningssystemet. Begränsningar som kan få till följd att motorn i en POD överdimensioneras, gentemot fartygets effektbehov, sådan att elmotorn vid drift inte ska generera lika mycket värme och därmed undvika de höga statortemperaturerna. En effektiv kylning av hotspoten och därigenom en tangentiellt mer uniform temperatur skulle därmed medföra att elmotorn kan; dimensioneras mer effektivt och därigenom ge en lägre installationskostnad, uppnå en högre utnyttjandegrad samt leda till en förbättrad hydrodynamisk verkningsgrad.

    Rapporten ämnar genom både analytiska och numeriska simuleringar utvärdera ett flertal olika passiva kylningsmetoder som kan appliceras över POD-husets hotspot. De tilltänkta kylningsmetoderna baseras i grunden på två olika principer. En av principerna, kallad utvidgade ytor, avser kyla hotspoten genom att underlätta överföringen av värme från hotspoten till en förbipasserande fluid där den andra, genom tillämpning av ett ledande material, leder värme från hotspoten till en omgivande kallare yta.

    Resultaten visar att alla de tilltänkta modifikationerna, i varierande grad, möjliggör en temperatursänkning av det vertikala hotspotområdet, vilken är belägen intill luftkylningskanalen. De modifikationer som presterar bäst är modifikationerna som tillämpar en heatpipe som ledande material och modifikationen utvidgad solid gjort av koppar. Dessa modeller visar en 60 procentig temperatursänkning av den vertikala hotspoten relativt referensmodellen. Rapportens resultat kan även visa en temperatursänkning av luften då modifikationen ledande stag tillämpas, vilket är gynnsamt för fartygets luftkylningsprocess. 

  • 279.
    Jakobsson, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Implementering av 5S vid LTE AB2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Life Time Engineering AB har under en längre tid saknat struktur i sin praktiska verksamhet som framförallt består utav en produktion av signalmarkörer för ubåtar. För att strukturera upp verksamheten samt klara av större beställningar har man beslutat sig för att vidta åtgärder och en av dessa åtgärder har varit att implementera verktyget 5S. 5S används inom ”Lean production” eller ”Lean” som det också kallas. Lean är en filosofi vars syfte är att eliminera alla faktorer i en produktion som inte är värdehöjande för produkten. 5S är ett verktyg som hjälper till att effektivisera en produktion genom att skapa ordning och reda på arbetsplatsen och på så vis minimera tidsslöseri, 5S bidrar även till att förbättra arbetsmiljön och säkerheten på företaget. Namnet 5S kommer från att de fem stegen i metoden som alla börjar på bokstaven S: sortera, strukturera, städa, standardisera samt skapa vana.

     

    Under 20 veckor har ett arbete utförts i företagets lokaler i Karlstad där 5S har implementerats och analyserats med målen att strukturera upp verksamheten, effektivisera företagets produktion samt förbättra arbetsmiljön. En stor del av arbetet har gått ut på att undersöka hur väl verktyget 5S är anpassat för mindre, flexibla företag som Life Time Engineering samt hur personalen ställer sig till förändringen. Det har även undersökts vilka möjligheter det finns att spara pengar på en implementering i och med att tidsslöseriet minimeras samt hur mycket uppstartstiderna kunnat förkortas.

     

    Arbetet har visat att en effektivisering av produktionen är möjlig då uppstartstiderna per batch har kunnat reduceras med 47 minuter. Ett frågeformulär har visat att de anställda varit mycket positiva till den nya arbetsmiljön och de nya arbetsrutinerna.

  • 280.
    Jakobsson, Hanna
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Sjöberg, Maria
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Belöningars påverkan i arbetslivet: En jämförande studie mellan chefers och medarbetares upplevelser av belöningar2007Independent thesis Basic level (degree of Bachelor), 20 points / 30 hpStudent thesis
    Abstract [sv]

    Belöningar finns på alla arbetsplatser, men sättet de tar sig uttryck på kan vara mycket varierande. De kan vara av ekonomisk, materiell eller immateriell karaktär och har alla till uppgift att motivera de anställda. Ekonomiska belöningar är belöningar i form av pengar och kan exempelvis utgöras av en bonus. Materiella belöningar innebär en kostnad för företaget men utdelas i annan form än pengar till de anställda, exempelvis genom studieresor eller personalfester. Immateriella belöningar, såsom feedback eller en befordran, utgör ingen kostnad för företaget utan delas ut för att motivera på ett psykologiskt och socialt plan. Detta är en studie med avseende på att undersöka upplevelsen av belöningar på ett företag. Den är gjord i ett jämförande perspektiv i syfte att undersöka om det föreligger någon skillnad mellan hur chefer och medarbetare upplever belöningar samt vilka belöningar som upplevs vara mest motiverande. Därtill var vi intresserade av om det finns något samband mellan inställningen till arbete och hur belöningar upplevs.

    Studien är baserad på en kvalitativ metod där intervjuer legat till grund för analysen. Vi intervjuade fyra chefer och fyra medarbetare som alla innefattas av företagets belöningssystem. För analysen av intervjuerna har delar av grounded theory använts där fyra intressanta kategorier identifierades. Dessa har sedan satts i relation till befintlig teori och litteratur för att kunna diskuteras vidare.

    Resultatet visade att det inte föreligger några större skillnader mellan chefers och medarbetares upplevelser av belöningar. Alla var överens om att belöningar fyller en vikig funktion men sättet den ges på och att den är personligt riktad upplevs vara långt mycket viktigare än dess konkreta innehåll. Detta eftersom den då fyller ett behov av att känna sig sedd och bekräftad av både chefer och medarbetare. Immateriella belöningar såsom en befordran, beröm, feedback, utbildning eller ett enkelt tack upplevs vara mer motiverande än ekonomiska belöningar. Anledningen till detta är att immateriella belöningar upplevs bidra till individens personliga tillfredsställelse och utveckling. Löneförhöjning är dock en mycket uppskattad ekonomisk belöning eftersom den ses som ett långsiktigt bevis på att man gör ett bra jobb. Att ha en god företagskultur upplevs som viktigt och här fyller materiella belöningar en stor funktion genom att de ofta bidrar till att skapa en god social gemenskap. Vi fann även ett samband mellan att ha en engagerad inställning till arbete och att motiveras mest av immateriella belöningar. Detta tror vi kan vara användbart att ha i åtanke när belöningssystem utformas. Sammanfattningsvis kan sägas att ekonomiska, materiella och immateriella belöningar alla är mycket uppskattade men fungerar motiverande på olika sätt. Bortsett från den vanliga lönen skulle man dock klara sig utan ekonomiska belöningar men utan immateriella belöningar är det svårt att hålla motivationen uppe.

  • 281.
    Jakobsson, Maria
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Kortfält, Anna
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Skanskas väg till effektivare anläggningstransporter: En studie om leverantörssamarbete2010Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Priset för anläggningstransporter har under de senaste åtta åren ökat kraftigt. Dessa transporter är en stor och betydelsefull del för byggföretagen, och Skanska Sverige AB köper anläggningstransporter för cirka 1 miljard kronor per år. På grund av den kraftiga prisökningen samt att Skanska har sett stor potential av effektiviseringar inom anläggningstransporter har de startat projektet ”Effektivare Anläggningstransporter”. Ett mål med projektet var att minska kostnaderna för anläggningstransporter genom effektiviseringar. Detta arbete har genererat en kraftig sänkning av antalet leverantörer samt att enhetliga avtal med dessa leverantörer har tecknats. Syftet med detta examensarbete är att utveckla ett nationellt arbetssätt för att förbättra Skanskas samarbete med leverantörer av anläggningstransporter.

    I byggbranschen ser alla projekt olika ut. Varje byggprojekt fungerar som ett eget litet företag vilket medför att byggbranschen är en decentraliserad bransch. Inom varje projekt finns det en produktionschef samt produktionspersonal. Det är produktionschefen som ansvarar för allt från ekonomi och tidsplanering till beställning av transporter och övrigt material. Idag sker alla beställningar av transporter via telefon och oftast samma dag som transporterna behövs eller i bästa fall dagen innan. Anpassning till ny teknik i transportbranschen sker långsamt och än idag är det oftast handskrivna följesedlar. För att hitta effektiviseringar har Skanska påbörjat ett effektiviseringsarbete med sina ramavtalsleverantörer. Detta innebär att Skanska ska ha utvecklingsmöten med dessa leverantörer två gånger per år för att diskutera fram effektiviseringsåtgärder.

    Effektiviseringsarbetet har stannat av på grund av omorganisationer i Skanska samt den rådande lågkonjunkturen. Det är detta effektiviseringsarbete som ska utvärderas och förbättras i detta examensarbete. Denna studie genomfördes med hjälp av ett antal intervjuer där det framkom att största problemet var att det inte fanns någon ansvarig på lokal nivå för att driva effektiviseringsarbetet. Några andra problem som upptäcktes var att det inte fanns något uttalat mål med utvecklingsmötena samt att det inte fanns något mätbart uppföljningssystem som visade utvecklingen. För att lösa dessa problem studerades teori om organisationer och kultur, gruppdynamik, inköp, relationer samt prestationsmätning.

    Alla är eniga om att effektiviseringsarbetet är viktigt och bör fortsätta men det krävs dock vissa förändringar. Genom bättre planering och bättre intern kommunikation kan samarbetet med Skanskas leverantörer förbättras. För att hitta effektiviseringsåtgärder bör utvecklingsmötena ha tydliga mål. Det krävs även en person på lokal nivå som ansvarar för att mötena blir av och att effektiviseringsidéer förs vidare till inköpsavdelningen. Det allra viktigaste är att inköpsavdelningen ska kunna mäta och följa upp effektiviseringsarbetet. Detta kommer att kunna ske med hjälp av den modell som presenteras i slutet av denna rapport. Modellen kommer att lösa de problem som denna studie har uppmärksammat och är konstruerad på ett sätt så att modellen är enkel att använda.

  • 282.
    Janebrink, Niklas
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Construction of tilt table with high loads: A construction with complete hydraulic system2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    At Uddeholm AB, they today use two overhead cranes with chains to move and tilt steel sheets for visual inspection of surface defects. The tilting is done to give the operator a better view of these defects using reflection of light. The problem with this approach is that it is combined with danger of life with hanging load, in case a chain breaks. Therefore Uddeholm AB would like to develop a tilt table that can be mounted on their lift table they use today.

    To solve this problem, 5 concepts was developed using a product development process. The chosen concept was further developed into a product that met the defined load case to tilt the sheets, weighing up to 20 tonnes, 55 degrees. The design that was selected use two points of rotation and is driven by three hydraulic cylinders.

    The structure has been calculated by hand and with the structural mechanics software Ansys. To tilt the table a complete hydraulic system was developed and dimensioned. The hydraulic system has been calculated by hand and simulated by a computer program called Hopsan developed at Linköping University. 

  • 283.
    Jansson, Adam
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics, Science, Mathematics and Engineering Education Research.
    Further development of Sand Bed Burner2014Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    To determine whether a weapon system meets the requirements set for insensitivity, the system is getting exposed for special tests. One of these tests shows how the system reacts when it ends up in a fire. This test is called the "Fast Cook-Off (FCO) Test", called FCO-test, and performed with a Sand Bed Burner (SBB). According to primary testing provision, the fuel for this test is used of jet fuel such as Jet A-1. A project at Bofors Test Center (BTC) is in progress to use an alternative fuel of Liquefied Petroleum Gas (LPG). This fuel is very advantageous compared to jet fuel in terms of environmental impact, work environment and testing costs.

    The aim of this thesis is to improve the existing test equipment considering fire over the entire surface and solve the problems with dropped gas flow and freezing of gas bottles.

    SBB works in the sense that the new petrol LPG streams into the SBB and expands in the free space below the sand bed before the gas will diffuse through the bed of sand and the fire engulfs the object.

    LPG is a condensable gas that requires oxygen. LPG exceed from liquid to gas phase and needs a large lateral surface to take up more energy which results in better evaporationto the phase transfer. Reaction products from complete combustion of LPG are only water vapor and carbon dioxide, the same as in your exhaled air.

    To solve these problems it was needed to change P11 composite bottles to P45 steel bottles to get a longer evaporation and larger lateral surface. Four flow inlets instead were used of one into SBB for a better stream in the free space under the sand bed. Propane regulators used to get a lower and more constant flow to avoid freezing. Compressed airconnected tothe SBB to geta mix between oxygen and LPG.

    The result shows in higherheat radiation efficiency even though the flow was settled down to 1/3 with the new propane regulators. In test 2 the value was 37 kW/m2 and in test 7 it was around 57 kW/m2. Because of a smaller flow and bigger steel bottles the freezing disappeared. Smaller grain of sand together with four inlets and compressed air gave a more complete combustion.

  • 284.
    Jansson, Charlotte
    Karlstad University, Division for Business and Economics.
    Arbetsmotivation och hälsa bland sjukvårdspersonal2006Independent thesis Advanced level (degree of Magister), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Det är av intresse för alla organisationer att skapa en tillfredsställd personalstyrka som är motiverad till att prestera bra på arbetsplatsen och därmed har arbetsmotivation. Dock krävs det en frisk personalstyrka som är vid hälsa och därmed är närvarande vid arbetsplatsen, för att organisationen ska kunna ta del av dessa prestationer. Det är därför viktigt att finna faktorer som uppmuntrar personalen att prestera bra på arbetet och samtidigt främja välmående. Den här studien undersöker huruvida det föreligger ett samband mellan arbetsmotivation och hälsa bland sjukvårdspersonal. Resultatet bygger på en enkät med fasta svarsalternativ, vilken delats ut till 218 respondenter bestående av undersköterskor och läkare vid Sahlgrenska Universitetssjukhus i Göteborg.

  • 285.
    Jansson, Daniel
    et al.
    Karlstad University, Faculty of Technology and Science.
    Andersson, Lennart
    Karlstad University, Faculty of Technology and Science.
    Utveckling av säte till kulventil SKV2007Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    This report contains a degree project made by the mechanical engineering students Lennart Andersson and Daniel Jansson. The project has performed in assignment by SOMAS Valves AB in Säffle. SOMAS are leading in development on control and on/off valves. To maintain this position they always want to improve their products. One way in this development is valves that are more tightened.

    The purpose with our project was to investigate another seat design on a HiCo (High Cobalt Alloy) seat to a SKV 150 PN 25 valve and compare this to an original HiCo seat.

    By modifying the seat on a ball valve we want to achieve a valve that leaks lesser then a valve whit original seat. At the same time the maneuver torque should be retained or better and the wear should not be worse.

    The project begins with a theoretic investigation of valve forces, maneuver torque and seat design. A manufacturing drawing was made in Pro ENGINEER and handed over to SOMAS AB for manufacturing. Four seats are made in the new design and will be compared with four original seats about maneuver torque, tightened and wear. The idea to make a trace in the middle of the seat was that it would tighten earlier.

    Water under pressure is pressed against the valve to test its resistance of leaking, the leaking is measured by a measure glass. The modified seats leaks more then the original seats, even though, according to the theory they should have a higher seat force. Even the maneuver torque is higher on the modified seats, but this increase is not a problem. All seats was tested to watch their resistant to wear, to test this, a valve mounted with seats is opened and closed 600 times (about 3hours). Because of the short wear time it’s hard to see and validated wear, but on the after coming pressure test the valve is more tightened.

    A reason to leaking is the tolerances between the seats and the ball. The reason why the modified valve seat leaks more is probably that the lathe area functions as a channel for the medium.

    The medium which passes the first tightened area can easier find a new way to pass the second tightened area.

    The conclusion is that the new seat design is nothing to go further with, but there are proposals for a new seat design.

  • 286.
    Jansson, Magda
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Modellering av ett flerbostadshus med solcellsanläggning och energilagring i Sverige: Egenkonsumtionsgrad, klimat och ekonomi2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Klimatförändringar på jorden sker i snabbare takt än för den naturliga variationen och det står klart att antropogena utsläpp påverkar och kommer fortsätta påverka jordens klimat under lång tid framöver. För att minimiera klimatpåverkan som härrör från mänsklig aktivitet måste mängden utsläpp av växthusgaser minska, vilket främst görs genom att minska förbränningen av fossila bränslen. Den internationella energitillförseln samt elproduktionen kommer till störst del från fossila bränslen, i form av kol, koks, naturgas och olja. Det finns flera energikällor som kan ersätta fossila bränslen, där vattenkraft sedan länge nyttjats och är i nuläget den största förnybara elproduktionskällan i världen. Andra förnybara elproducenter är vindkraft och solkraft som tack vare elcertifikat och andra stödsystem har växt och med största sannolikhet kommer fortsätta växa framöver. Under året 2016 producerades omkring 0,1 TWh solel i Sverige, men Kungliga Ingenjörsvetenskaps-akademin menar att solenergi har en bruttopotential att producera upp till 50 TWh el om alla för ändamålet lämpliga tak beläggs med solcellspaneler. Problemet med solkraft är att den är intermittent till sin natur och för att den ska kunna spela betydande roll i framtidens elproduktion krävs smarta system kring energilagring. Lagringssystem finns såväl små- som storskaligt och kan innebära alltifrån dygns- till säsongslagring. Att se till mindre energi-system har fördelen att kunna appliceras inom en närmare framtid än utifall att helt lands infrastuktur skulle behöva omkonstrueras.

    I denna studie modellerades ett flerbostadshus med solcellsanläggning och energilagrings-system i Sverige, där fokus låg vid att öka graden egenanvänd solel samt analysera vad dessa system innebär för klimat och ekonomi. Tre energilagringssystem modellerades; (1) dygns-lagring genom litium-jonbatteri; (2) dygnslagring genom vätgaslagring samt (3) säsongs-lagring genom vätgaslagring. I enlighet med tidigare studier inom området ökade graden av egenanvänd solel i fastigheten för samtliga undersökta lagringssystem.

    Den klimatmässiga analysen i denna studie visade att dygnslagring genom litium-jon-batterier har den lägsta klimatbelastningen av de undersökta lagringssystemen. Att lagra elenergi över säsong genom vätgaslagring har den högsta klimatbelastningen, där vätgas-tanken identifierades som enskild kategori med högst klimatpåverkan. Gällande litium-jonbatterier återfinns den största klimatbelastningen vid användandet av elenergi under tillverkningsprocessen. I denna studie framkom även att de undersökta lagringssystemen har ett nästintill linjärt samband mellan klimatbelastning och maximal lagringskapacitet. Vilket gör att energilagringssystemen skulle kunna göras i mindre eller större skala utan att belasta klimatet ytterligare, baserat på koldioxidekvivalenter per kilowattimme el.

    Det är enbart lagringssystemet med litium-jonbatteri som minskar fastighetens totala drifts-kostnad. Den årliga besparingen är dock med högsta sannolikhet inte nog stor för att batteri-systemet skall hinna återbetalas under den förväntade livslängden. I denna studie antas pris-sättningen för inköpt elenergi variera till viss del, då elpriset baseras på månadsmedelvärden från Vattenfall AB samt att elnätsägaren Kristinehamns Energi AB har högre effektavgift mellan 1 november – 31 mars. Långtidsprognos kring framtida elpris menar dock att det kanske en ännu större variation över året och även över dygnet, vilket kan tänkas gynna ekonomin kring energilagringssystemen.

    För att solenergi ska kunna spela roll i den totala elproduktionen, krävs smarta system gällande energilagring. Tekniker för energilagring finns, men fler studier måste utreda energilagringars egna klimatbelastning för att klimatsmarta beslut skall kunna tas idag och i framtiden.

  • 287.
    Jansson, Per
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Automatiserad laddning och plundring mellan magasin2013Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This thesis has been carried out within the bachelor program for mechanical engineering at Karlstad University in collaboration with BAE Systems in Karlskoga. The purpose with this work was to design a mechanism and associated parts for loading and unloading of shots between primary and secondary magazine in BAE's new 40mm's ship gun.

    Parts designed or redesigned among other things a transfer mechanism for shot at loading and unloading, well as a hatch mechanism which makes the shots do not fall out of the primary magazine when making separate use. Various important details have been designed to maintain a good functionality of the mechanism.

    The construction work has mainly been carried out in the CAD software Solid Edge and its associated FEM module. The construction work has also been carried out on rough calculations for constructed details in order to ensure that they meet the stringent requirements of military use in tough marine environment. Two of the most critical parts of the structure where analyzed with the FEM module for estimating the stresses in the material at the applied load.

    The final design, which is a result of the thesis, meets the requirement specification and the set targets. Given the very limited space at the dock between primary and secondary magazine, the final outcome is considered to be a robust and durable construction. Manufacture of a prototype for testing and evaluation of the design is the next step for the final adjustment and an eventual production.

  • 288.
    Jarnbro, Marie
    et al.
    Karlstad University, Faculty of Technology and Science.
    Kaborn, Ulrika
    Karlstad University, Faculty of Technology and Science.
    Mjölkkyl till espressomaskin: Impressive cooler2006Independent thesis Basic level (degree of Bachelor), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    The project was made in cooperation with Coffee Queen AB, Arvika. The task was to develop and design a new cooler for the milk to Jura Impressa X9, an espresso machine. The good assistance with staff at Coffee Queen and engineers in China and at KPA in Karlstad led to a solution to the problem. It was a long road to get there, many different concepts was developed. When the day came to decide which concept to work with, the choice stood between two different technical solutions. Alt 1: The classic mini-fridge with today’s technique but a new design. Alt 2: Thermos with external cooling and a design which follows the X9. We choice alt 2 because of the fact that part of the production would fit Coffee Queens factory and therefore would it be possible to keep the costs down. The fact that it is a totally new idea in this business made it even more interesting and easier to make a choice. Both design and function is new, which make it interesting to keep working with. In cooperation with engineers in China there will be made a construction so they can make all necessary tests. This will probably happen autumn 2006. The new technique which the group has come up with is that all technique lays external, in a shell made of polypropen, which make it possible to clean the thermos in the dishwasher. Thermos: Vacuum-shaped in stainless steel with bottom of aluminium, covered with a protected surface, that works like a cold plate. Shell made of pp: shape-molding in polypropen and enclose the coolingsystem. This system are Peltiere, where the cooling is generated, spacer block and heat sink, where the heat are led away, and the fan which takes in cold air and blows out warm. The project has become much larger than Coffee Queen expected from the beginning so they will continue this work even after the students have done their share of the project. The new technique is the big question which requires more tests. These tests will carry through as soon as the group has sent all drafts of design and all info that has been gathered during the project. When the factory in China has made a construction of it they will send it to Coffee Queen and the project-group will be contacted to have a chance to take part of these tests.

  • 289. Jenny, Andersson
    Implementering av 5S i smörjdepåer: Ett projektarbete för att bidra till effektiviseringsarbetet på BillerudKorsnäs Gruvön2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 290.
    Jernberg, Hannes
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Utökade tillämpningsmöjligheter för turbinlösning i våtpartiet hos tissuemaskiner: Konceptförslag som möjliggör tillämpning av turbinlösning för maskiner vars banbredd är bredare än 2,9 meter2014Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    AbstractThis thesis is the final part of the Innovation and Design Engineering Programme (180 ECTS credits)at the Faculty of Health, Nature and Engineering Science at Karlstad University. The extent of thisthesis is 22.5 ECTS credits and has been performed independently by Hannes Jernberg during thespring of 2013. Metso Paper Karlstad AB is the task maker of this project, and Arvid Johansson is thecompany Representative. Metso Paper Karlstad AB is one of the world leading developer andmanufacturer of tissue paper machines.In the current situation, the company has developed and patented a power management systembased on a Cross Flow Turbine. The current construction is limited to a paper width of 2.9 meters.The company wants to take advantage of all the opportunities provided by the patents, to develop aturbine solution paper machine with a paper width that is wider than 5.5 meters, and give the abilityto manufacture paper for lower energy consumption which is an important part of the production asit is very energy intensive.Problems arise with the increasing length of the turbine, ultimately resulting in that the deflectionbecomes too big and that the momentums, due to the increased torque the turbine blades breaks.By applying the design process, this work has resulted in a number of potential solutions to theproblem. Sketches, LEGO and engineering methodologies have contributed to the good result.The recommended solution generated by this project is to place two regular sized turbines by 2.9meters. The first turbine is placed in its optimal position at the Driver side of the turbine, themomentum provided by the water is leaded by a shaft towards the engine side of the machine. Thesecond turbine is placed directly under the first shaft. This allows the second turbine take care of therest of the water and energy.

  • 291.
    Joensen, Mortan
    et al.
    Karlstad University, Faculty of Technology and Science.
    Nilsson, Maja
    Karlstad University, Faculty of Technology and Science.
    Utvärdering av energibesparingspotential vid tillämpning av värmepump i diskmaskin: OBS! Sekretessbelagd tills vidare2009Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    For an average detached house in Sweden today about 5000 kWh are used for household electricity. Of these 5000 kWh 7% are used to run dishwashers. The streamlining of dishwashers has above all strived for a lower water and energy use, a short process time along with a more efficient cleaning of the dishes.

    There are however limits for how efficient the dishwashers can be made with traditional technology and acceptable costs. Therefore producers have, during recent years, started looking for less traditional methods, for example the use of a heat pump to reduce the energy use.

    The purpose of this examination work has been to find system solutions for an application of a heat pump in a dishwasher and to evaluate the possible energy saving for each solution.

    The goal has been to find and describe possible system solutions, which came up during the idea generation. To choose some of these for a closer investigation, to decide a fitting mechanical power for the compressor and to calculate the energy saving these solutions give rise to.

    The method has consisted of a literature study, an idea generation, which takes the heat sources and sinks in consideration and a modelling in MATLAB’s Simulink of the selected solutions from the idea generation, which has been used to fit a mechanical power for the compressor.

    The result of the idea generation was two solutions, an outdoor air solution, which collects heat from the outdoor air and gives it to the cold water which enters the machine and a energy storage solution, which collect heat from a heat stock to give to the cold entering water. A modelling of these show an energy usage of 0,24 respectively 0,17 kWh for the outdoor air solution, with a heat source temperature at 10 °C respectively 5°C and a energy usage of 0,22 kWh for the energy storage solution for one round.

    The conclusion that was drawn was that the compressor of the energy storage solution should deliver a mechanical power of 240 W to the refrigerant.

  • 292.
    Johansson, Anton
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Influence of the adhesive on the mechanical properties in laminated multi-layer paperboard: Evaluation of two common dispersion adhesives, their failure modes, internal strength and influence on bending and tensile properties2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The objectives of the thesis were to investigate the adhesives influence on the mechanical properties in laminated multi-layer paperboard. The study also strived to find a method to investigate the interface strength of the adhesive layer.

    This was investigated by constructing handsheets of laminated paperboard by gluing a bulky, CTMP center ply, Chromofoil, of two different grammages, 290 g/m2 and 360 g/m2, together with two outer plies of ordinary copy paper, Multi- Copy 80 g/m2. The sheets were glued with two types of dispersion adhesives, a starch based adhesive and a polyvinyl acetate based adhesive. Twelve types of test specimens were constructed and tested in a series of mechanical tests, which involved a tensile test, a two-point bending test and a Scott Bond test. The method called “digital image correlation” was used trying to investigate the interface strength of the adhesive layer.

    The study also involved an evaluation of the possibility to predict the bending stiffness of laminated multi-layer paperboard by using calculations according to classic laminate theory. The results show that it is fully possible to use these calculated values as a prediction, with low risk of overestimating the bending stiffness of the paperboard and without involving the adhesive layer in the calculation.

    The method provided high absolute values in bending and tensile properties, which increased with increasing amount of glue applied. This came at the cost of grammage, which lead to low index values. The overall conclusion is that the effect from the adhesives is somewhat negative, since the mechanical properties would have been improved if the adhesive had been replaced with more fiber.

    The major source of errors during the experiments was the roughness of the manufacturing method. This lead to an uncertainty about whether the right amount of adhesive had been applied to the test specimens. Due to this the validity of the results could be questioned.

    Digital image correlation proved to be a rather sensitive method that requires a high accuracy setup and execution for it to be applicable in this type of study.

    The failure mode of the glue seam correlated well to the amount of glue applied. A lower amount of adhesive applied increases the likeliness of failure of the glue seam. 

  • 293. Johansson, Casper
    Optimering av slipningsprocess på belagt bandstål: Analys av parametrars påverkan på restspänningar2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report is a degree project for a Bachelor of Science degree with specialization in mechanical engineering MSGC17 at Karlstad University. It’s made by a graduate engineering student specializing in mechanical engineering MSGC17 at Karlstad University. The work was carried out at voestalpine Precision Strip AB in Munkfors. Voestalpine Precision Strip AB is a company where they roll precision steels. To one of their products, an abrasion-resistant coating is ground to get the desired shape to the customer. The purpose of this work is to investigate the formation of residual stresses in the coating when the coating has been ground. The aim of the work is to optimize the parameters in the grinding machine so that the residual stresses are reduced and deliver a grinding recipe with recommendations for voestalpine.

    The method that was used to investigate the influence of the parameters was to make a design of experiments (DOE) on the process. By doing this, different parameters could be tested in high and low value simultaneously on one and the same band. 5 parameters were examined which were considered to affect residual stress formation. The factorial design was a 2 5−2 factorial design. The tests were carried out in 8 different variations where the parameters were run in low or high level. After grinding, the residual stresses in the material were measured with X-ray diffraction to obtain values for residual stresses. The X-ray diffraction measured the residual stresses in 3 different directions. With the stresses in the three different directions, the main stresses were also calculated.

    The result showed that parameter B is a recurring parameter in all trial planning, and it should be at a high level. In the grinding recipe voestalpine wanted will A and C run as much they’re required too, B at high level, D at low level and parameter E at a high level. With this recipe the residual stresses are theoretically reduced in the material.

  • 294.
    Johansson, Daniel
    et al.
    MSE Weibull AB.
    De Vin, Leo
    Högskolan i Skövde.
    A Low Cost Video See-Through Head Mounted Display for Increased Situation Awareness in an Augmented Environment2008In: Proceedings of 5th INTUITION International Conference: Virtual Reality in Industry and Society: From Research to Application, 2008, Turin, Italy: INTUITION , 2008Conference paper (Refereed)
    Abstract [en]

    A head mounted display is developed for use in an immersive augmented reality simulator for virtual training. The simulator requires a video see-through parallax-free display to accurately mix the real and virtual worlds. High field of view is also required to allow use of peripheral vision in order to create a higher sense of awareness for the user. Due to high cost associated with commercial off-the-shelf display systems, a custom solution is designed and developed by combining hardware and software. It is shown that it is possible to build a low cost display system that provides the necessary attributes and acceptable compromises for the current type of application.

  • 295.
    Johansson, Daniel
    et al.
    MSE Weibull AB.
    De Vin, Leo
    Högskolan i Skövde.
    Design and development of an augmented environment with high user mobility for training purposes2008In: Mechatronics 2008: Proceedings of the 11th Mechatronics Forum Biennial International Conference,  University of Limerick, Ireland, 23-25 June 2008., Limerick, Ireland: University of Limerick , 2008Conference paper (Refereed)
    Abstract [en]

    The paper describes the design and development of a novel cost effective simulator for training of situation awareness, strategy and co-operation. By mixing real and virtual realities in combination with wireless and body-mounted hardware, the result is an augmented environment that allows for high physical mobility against a relatively low cost.

  • 296. Johansson, Dennis
    Reduktion av mikroorganismer i diskmaskiner  med vattenånga.2017Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Bacteria are a type of microorganism that causes several kinds of problems in dishwashers, one problem being that the bacteria create strong and difficult smells. Bacteria arise from the fact that food residue on the dirt tray serves as nutrition for the bacteria for a long time. To minimize the bad smell, use a dishwashing program with hot water and usually a dishwasher detergent. This is independent of the amount of dirty disk actually in the dishwasher. It will be both a cost issue and an environmental issue through a waste of natural resources. The optimum is a solution that is directly aimed at removing and reducing existing microorganisms on the counter as well as in the dishwasher that does not use machine dishwashing and minimal water and electricity. This then does not need a more intensive program. The purpose of the study is to show how hot steam can be used to reduce the amount of bacteria on the dirty disk.The method used to test the reliability of the vapor treatment system was to use a solution of yeast cells with sodium chloride which had grown into a 24-hour heat sink in a pressure plate with agar solution used as a yeast cell feed. Then they were brought into a specially configured dishwasher where hot steam was injected into the system to work to reduce the bacteria on the plates.The number of microorganisms was compared before and after the treatment of the vapor. The tests were conducted until there was a clear connection between water use, the time of steam treatment and the reduction of yeast cells. This continued until a 95 percent reduction of microorganisms had been achieved throughout the dishwasher regardless of where the contaminated plates were located.The conclusion is that the steam treatment was more expensive than the existing technology, and the dishwasher needed to be supplemented by a method of heating the water to 100 °C. A simple rinse with hot water gave similar results and was cheaper and easier as the machines were already equipped with such a functionThere is a market for the steam method, as the method is especially interesting for individuals with additional disinfection needs, for example for people with poor immune system.

  • 297.
    Johansson, Emil
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Bomfjädring till hjulgrävmaskin:  2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The task was to design a damping system to Volvo´s wheeled excavator EW160C with assignments from Swecon. The type of solution that would be relevant turned out to be a kind of accumulator system. By connecting an accumulator to the piston side of the cylinder, the accumulator operates as a shock absorber as the oil-flow from the cylinder of the crane, which moves up and down on uneven surfaces, flows into the accumulator and gets suppressed by means of a diaphragm or a piston in the accumulator that is pressurized by a gas. The oil flow attenuates when the gas is compressed.

    At the beginning of the thesis work, a project plan was made with a time schedule and a risk analysis. Then the research began for different types of aftermarket kits and companies that are working with this type of solutions. A meeting was arranged with Anders Tågmark who´s working for Hydac, a company that is selling hydraulic components. After the meeting we decided to cooperate. A decision was made that I should bring Anders concepts of the solution and Anders should give me examples of components that were needed. The research work also contained a study visit at Swecon in Eskilstuna, where the people that made the request about this work in the beginning was interviewed. At this meeting they made a priority list of what they thought was most important to have in mind in the concept development. The result of the research was that the solution should be simple and as cheap as possible, so it wouldn´t compete with a solution that Volvo might develop in the future. The goal in this project was therefor to make an aftermarket kit. Some of the requirements was that the damping system was allowed to cost between 15-25 000 Swedish crowns for the customers to buy, and that the system should be easy and quick to mount on the machine.

     

    The main questions of the concept development, was which type of accumulator that should be used and where to place the system. One of the concepts was to place it on the boom-cylinders, and the other concept was to place it on the tilt-cylinder. It turned out that both concepts met the cost requirements from Swecon in terms of components. However, costs will be added for the completion of the solution for manufacturing, mounting, purchasing and spare parts support.

    The result was to use a piston-accumulator and place it on the tilt-cylinder, because the concept for the tilt-cylinder was simpler and less expensive

  • 298.
    Johansson, Gustaf
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Chassiintegrerade lastceller: Installation i fjädersäte på Scania tandemboggibakaxlar2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The thesis presented in this report has been made on behalf of Scania and their basic frame design department with the subject to solve an implementation of a weight sensing system in the chassis. The system is supposed to be implemented in the seat springs, and the reason for this is that all the force will have to go through the weight sensing transducers. With all the force going through the transducers the weight sensing system will not be sensitive for the differences in tolerances from manufacturing. The transducers could be pre-calibrated to avoid a calibration of the whole vehicle after it’s completed from the manufacturing line.

    Weight sensing systems is today a reality in trucks with air springs. Complete systems is also sold in the big aftermarket for trucks. None of Scanias competitors have a solution for this as of today.

    The thesis was from start limited to only process the BT-301S bogie. A system will likely be easy to adapt to the other bogies with small modifications.

    Through the thesis possible problems are illuminated to understand the function and make a properly working weight sensing system. In the present bogie system the main problem for a proper function is the frictional forces that appears in the surface between the spring and the spring seat. 

    In the report a proposition with a rubber part between the spring and the spring seat is introduced, with the idea to get around the known problems with the frictional forces. The rubber itself does produce a reaction force when deformed, but the forces could through simulation be known, and hence compensated for. A rubber part under the spring would result in a contact surface much higher than today. A new spring, or a new version of the spring, will be needed for this solution to work.

    For the work to come, Scania need to decide what precision the weight sensing system need. But smaller decisions like the size and stiffness for the rubber part will also be needed. This thesis has only dealt with the bogie, but in a close future, the front axles need to be done. Much can likely be carried over from this thesis for that.

    A weight sensing might be possible to implement, but with what precision at uneven ground? Most likely will the variation in load on the transducers be too much. An approximation for the precision with a total span of 7% is realistic.

  • 299.
    Johansson, Helena
    Karlstad University, Faculty of Technology and Science.
    Nocturnal cooling: Study of heat transfer from a flat-plate solar collector2008Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    This thesis investigates the possibility of using an unglazed flat-plate solar collector as a cooling radiator. The solar collector will be connected to the condenser of a heat pump and used as cooler during nighttime. Daytime the solar collector will be connected to the evaporator of the heat pump and used as heat source. The two widely differing fields of application make special demands on the solar collector. The task is given by the heat pump manufacturer Thermia and the main objective is to find out whether a solar collector should be used as a cooler or not. The performance of the solar collector under varying environmental conditions is investigated using COMSOL Multiphysics 3.3. Only the cooling properties are investigated here. The performance of the solar collector as a heat exchanger is estimated using the effectiveness-NTU method, and the solar collector is found to be a good heat exchanger at low wind speeds. The heat transfer coefficients of the convection and radiation are determined for varying temperature and wind speeds. The convective heat transfer coefficient is lowered by tubes above the absorber plate and for a high convective heat transfer rate the solar collector surface should be smooth. For a high radiative heat transfer rate the surface needs to have a high emissivity. The cooling rate is higher from a warm surface than from a cold and since no temperature change of the heat carrier is necessary the solar collector should be kept at a high temperature. To increase the cooling rate alterations need to be made to the solar collector that makes its heating performance deteriorate. A solar collector that can be used for cooling is not an efficient solar collector.

  • 300.
    Johansson, Jimmy
    Karlstad University. Fakulteten för hälsa- natur- och teknikvetenskap.
    Utformning av en Bollutslungare: Produktutvecklingsprojekt av en bollutslungare för hundsporten Flyball2016Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report is a product development project of a ball launcher as requested by Sörmons HundklubbLKk. The project har been carried out as a thesis for the Bachelor of Science for the Innovation anddesign engineer program at Karlstad University.The client wished to begin training in a dog sport called Flyball. This sport can be likened to a relayrace where two teams of dogs race against each other. One dog per team runs along a path, leapingover obstacles, up to a ball launcher. When the dog jumps at the ball launcher to stop its momentumand turn back, a ball, launched about two feet, is to be caught by the dog. The dog then returns thesame way along the track as it came to switch with the next dog on the team. The last dog who finishfirst wins for their team.Due to large costs when importing a ball launcher, and the product not being available in Sweden,the client wanted a Swedish version developed. The goal was to minimize the price with the criterionto maximize longevity.The work of the project has followed the product development process as studied at KarlstadUniversity, with great influence by idea generation techniques, analog and digital sketching, 3Dmodeling and mechanical drawing techniques. Construction of the prototype has been carried out inthe workshop at Karlstad University with an evolutionistic design approach. A combination of lateralthinking for creativity and vertical thinking for logic and confirmation was used throughout theproject.The result of the project was a prototype that could be tested in a real environment at the dog cluband was confirmed to function as desired. Due to the availability of material at the workshop,construction of the ball launcher was possible at no cost to the client. This was a request, althoughnot a requirement for the project.The client also wanted to keep the prototype which was constructed to use within the club fortraining purposes. Therefore the ball launcher was completed to a finished prototype after projectclosure.

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