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  • 201.
    Gillberg, Peter
    et al.
    Karlstad University, Faculty of Technology and Science.
    Eriksson, August
    Karlstad University, Faculty of Technology and Science.
    Klimatanpassning av mjukpappersfabrik2008Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report is the documentation of a final project at the Karlstad university during the spring of 2006. The project consists of 20 credits where 5 credits are a literature study.

    The project was accomplished in cooperation with Pöyry. The assignment was to adapt a tissue factory to desert climate and in doing that provide the energy needed to operate and if possible reduce the need of the same.

    The factory has a need for steam in the production. The sun can be used to produce steam. The method used would be gathering sunrays from a big area and concentrating them in a small spot, a receiver. Thus high temperatures could be reached and steam produced. The solar collector that would be used is called “medium temperature solar trough”. It’s at type of solar collector that can move in one axis to catch the sunrays.

    To obtain an agreeable working environment in the factory there is a need for comfort cooling. The cold nights that are prevalent in desert areas can be used to cool the factory. A system with chilled beams installed in the ceiling of the factory will be used. The chilled beams contain circulating cool water. The cool water is heated while circulating during the day and thus has to be chilled during nighttime. The water is chilled in pipes on the roof during the night and then stored underground until used during daytime.

    The passive warming of buildings is a problem in desert areas when there is high sun intensity during the days. If the factory were to be built partially underground parts of the passive warming could be avoided. There is still a problem with the heat being generated in the factory. A well built ventilation system would need to be constructed to not lock this heat in.

  • 202. Girlanda, Orlando
    et al.
    Hallbäck, Nils
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Östlund, S.
    Tryding, J.
    Defect sensitivity and strength of paperboard in the out-of-plane tension and shear2005In: Journal of Pulp and Paper Science, 31(2), 100-104 (2005)Article in journal (Refereed)
  • 203.
    Gjelsnes, Kari
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Lindqvist, Sandra
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Personliga egenskaper i platsannonser: -en jämförande studie mellan arbetsgivaren och arbetstagarens synsätt2006Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Arbetsmarknaden idag ställer allt mer och fler krav på individen, vilket kan synas i organisationers sökande efter en medarbetare. Platsannonser är ofta ett verktyg i att hitta denna medarbetare, där krav som till exempel utbildning, erfarenhet och personliga egenskaper formuleras. Vissa menar att det inte bara kraven på en individ som blir högre, utan även annorlunda och nya krav ställs. De personliga egenskaperna blir allt viktigare för att en medarbetare ska kunna passa in i den befintliga grupp och organisation den kommer till. Vi tyckte det skulle vara intressant att undersöka mer om platsannonser och vad de signalerar än vad som gjorts i tidigare undersökningar. Vårt syfte med undersökningen har varit att utifrån platsannonser se hur man som arbetsgivare och arbetstagare ser på och uppfattar krav på personliga egenskaper som ställs för ett visst arbete. Vidare ville vi se om dessa uppfattningar gav upphov till olika förväntningar i relationen mellan en arbetsgivare och en arbetstagare.

    För att kunna ta reda på detta använde vi oss av en kvalitativ metod, med intervjuer som tillvägagångssätt. Vi tog kontakt med fyra olika organisationer, där arbetsgivaren letade fram en platsannons till en nyrekryterad. Vi intervjuade sedan arbetsgivaren samt den nyrekryterade arbetstagaren ifrån varje organisation, det vill säga fyra olika par där platsannonsen var vår utgångspunkt. Vi valde att enbart fokusera på de personliga egenskaperna.

    I vår undersökning har vi sett att arbetsgivaren har en tanke bakom kraven på de personliga egenskaperna som finns i platsannonsen, medan arbetstagaren anser att kraven ger en rättvis bild av tjänsten. Vi har även sett att uppfattningarna kring dessa krav kan ge upphov till förväntningar ifrån båda parter. Förväntningarna som uppstår kan vara på organisationen, arbetet och på arbetsrelationen.

  • 204.
    Glaad, Gustaf
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Pressurizing of high-pressure fuel system forsingle cylinder test cell2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis covers the development of a high-pressure fuel system for compression ignitedfuels such as diesel and diesel-like fuels that will be deployed into a single cylinder test cell at AVLMTC Södertälje, Sweden. The test cell is used by AVL to conduct research and testing of new fuelsfor their customers and this new fuel system will widen the span of fuels able to be tested by theequipment.This thesis focuses on pumping and pressurizing of the fuel, ensuring that all ingoing materialsare non-corrosive in this environment and compatible with the necessary fuels and lastly a safetyanalysis of the system with respect to operator and process safety. Other aspects of the projectsuch as mass flow measurements and fuel conditioning is covered in a sister thesis Mass flowrate measurement of compression ignition fuels in high-pressure stand-alone pump unit for singlecylinder test cell written by C. Aksoy [1].The goal of this thesis project was to deliver a finished manufactured fuel system and if the timeallowed for it, also validate its performance and finally installing and incorporating it into the singlecylinder test cell. The development process started with the writing of a product specificationoutlining the requirements and request on the product in a specification of requirements matrix andrelate these to product properties of the system using a quality function deployment (QFD) matrix.This document was then used as a base for further advancement in developing concepts to solveeach product property and weighing these concepts against each other using Pugh’s matrices. Thechosen concepts were then further developed, a flow chart for the system was developed as well asfuel lines and other supporting components were analyzed and chosen.In the end the high-pressure fuel pump from Scania’s XPI fuel system were chosen as well asa pressure transducer in the HP1000 series from ESI. Within the time frame of this thesis, theproject did not end up getting finished to the degree planned, but due to time constraints werehalted before starting manufacturing of the system. Some minor component choices remained aswell as documentation such as drawings and finalizing the physical layout of the system remained.All information regarding the remaining work needed to finalize the project and deploying thesystem in the test cell were outlined and with more time, the fuel system should fulfill its purposeof allowing testing and research of compression ignited fuel to be possible in the test cell.

  • 205.
    Gonäs, Lena
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Working Life Science.
    Arbetsmarknadskarriär, arbetsvillkor och hälsa2008Report (Other academic)
    Abstract [sv]

    Den här arbetsrapporten innehåller resultat från en befolkningsenkät som projektet Kön och Arbete vid Arbetslivsinstitutet utförde år 2001. Enkäten skickades till ett slumpvis urval på 10 000 personer i åldern 20-64 år i de tre kommunerna, Norrköping, Finspång och Söderköping. Enkäten hade till syfte att ge en övergripande bild av arbetsmarknadssituation, arbetsvillkor, fritid och hälsa för befolkningen i de tre kommunerna. Föreliggande arbetsrapport sammanfattar resultat från analyserna av sysselsättningsförändringar över tid och frågor kring arbetsvillkor och hälsa.

  • 206.
    Gonäs, Lena
    et al.
    Karlstad University, Division for Business and Economics.
    Spånt, Sara
    The Gender Pay Gap in Sweden: A national report2004Report (Other academic)
    Abstract [en]

    This report shows how gender wage differences has developed during the 1990s. An increased inequality was seen in the private sector and the largest wage gaps were found in occupations with highest monthly wages. In almost all occupational groups men had higher wages, but also experienced larger wage inequalities than women.

    One objective of the report is to compare results from studies that have standardasied for differences in age, education, skills and experience, to mention some of the factors. Results indicate that the gender wage gap seems to be stable and one policy conclusion is to gender mainstream wages policy.

    The report was produced to the European Commissions's network on Gender and Employment in 2002.

    Författarinformation:

    Lena Gonäs is professor of Working Life Science at Karlstad University and was expert to the European Commission network Gender and Employment 1996-2004. Sara Spånt has a Master of Political Science and worked as a research assistent.

  • 207.
    Grahn, Maria
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Development of portable unit for the coffee industry2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The project is executed along with the course “Degree of Bachelor of Science in innovation and design engineering”. The course takes part at the faculty of Health, Science and Technology at Karlstad University. The employer is in the coffee industry with a focus on the professional market. The company wishes to complete its product range with a new unit for the coffee industry. The technology behind the aid has already been developed by the company, of which the bachelor thesis concerns the design and construction of the product. By agreement with the company, the product's function will not be exposed in the report.

    The work follows the design process from start to finish including a project plan, pre-study, product specification, concept generation, configuration and prototype development. A large part of the work relates to the pre-study that has been conducted. The study is divided into two branches, one of which aims to chart the process of product development. The second purpose of the study is to answer how the product can be designed to reflect the company brand, current trends, human ergonomics and the cognitive understanding of the user. The pre-study does also aim to chart which stakeholders should be considered when developing the product. The process has been adapted to the fact that the product's function cannot be exposed to people who are not in direct contact with the project. As the product is new in the product range it does also lack precursor and known users. Due to these facts the company itself has had a very high influence in the decision making of the product´s final design. Therefore, trend and user analyses have been performed to broaden the understanding of the need that will be posed by the actual user.

    The final concept is a suggestion of how an exclusive variant of the unit may look. Potential end users of the product are almost everyone in the coffee industry, where the spectrum extends from waiters to the more skilled technician at a vending company which means that the unit will be used from once a year to each day. Thus, the design of the product is held simple to ease the cognitive understanding of the product regardless of user. The main materials in the product are aluminium and wood. The size of the device is selected to be ergonomically easy to handle and grip. The dimensioning is also motivated by the thought of giving a solid and stable expression. Complementary to the product a box has been developed to easy transportation of the product.

    The development of this type of product requires an understanding that the product does not work alone but acts in a context. In addition to its function, it acts as a service both for operator and customer by generating a certain type off experience. Today´s coffee and barista industry offer more than just receiving a cup of coffee, where identity and trends are important in addition to the taste of the cup itself.

  • 208. Green, Linnéa
    Förbättringsarbete inom eftermarknadsflödet i en verkstadsindustri: Identifiering, strukturering och prioritering av förbättringsförslag för kortare ledtider2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The project has been implemented as a thesis of Bachelor of Science in Innovation and Design at the Faculty of Health, Science and Technology at Karlstad University in the spring of 2016. Most of the work has been performed at BAE Systems Bofors AB’s aftermarket section in Karlskoga. The work included interviews and observations to identify the current flow and to apply methods of improvement on it. The feasibility study involved a large literature study on the methods and techniques of improvement, as summarized in the report's theoretical chapter.

    The methods that were used in the project were found in Lean, Six Sigma and the product development process, all of which were studied earlier in the education. Some examples of methods that were applied in the project were administrative spaghetti diagrams, Value Stream Mapping-analysis, ABC-analysis and brainstorming.

    A lot of problems were found in the aftermarket flow and twelve of those were more closely studied. These twelve problems were then summarized in a manual along with an in-depth analysis on why the problem had occurred, suggestions on how they could be resolved or improved and proposals on how a possible alteration of an introduced improvement could be measured.

    One example of problems that were found and gathered in the manual was that the company doesn’t work in an integrated way and need to prioritize the aftermarket flow. The suggested solution was to explain to the company why they would have to spend more resources on the aftermarket flow and motivate all employees that are involved. The solution also explained how important it is to focus on the customer and get the employees in the flow to work more efficiently.

    At the end of the manual a priority list of the twelve problem areas is presented. This priority list was made so the company more easily could start a discussion about the improvement work and how it could begin. 

  • 209.
    Gremyr, Ida
    et al.
    Chalmers Univ Technol, Dept Technol Management & Econ, Div Serv Management & Logist, Qual Management, Gothenburg, Sweden..
    Valtakoski, Aku
    Linkoping Univ, Dept Management & Engn, Business Adm, Linkoping, Sweden..
    Witell, Lars
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School (from 2013). Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Service Research Center (from 2013). Linkoping Univ, Dept Management & Engn, Linkoping, Sweden.;Karlstad Univ, Serv Res Ctr, CTF, Karlstad, Sweden..
    Two routes of service modularization: advancing standardization and customization2019In: Journal of Services Marketing, ISSN 0887-6045, E-ISSN 0887-6045, Vol. 33, no 1, p. 73-87Article in journal (Refereed)
    Abstract [en]

    Purpose - This study aims to investigate service modularization in a manufacturing firm, identifies service modularization processes and examines how these processes change the service module characteristics. Design/methodology/approach - The study is based on a longitudinal case study (2008-2017) of a manufacturing firm. The development of six service modules was analyzed using data from interviews with key informants, informal meetings and internal documentation. Findings - This study suggests five service modularization processes, and that service module characteristics, such as standardization and interconnectedness, change in different ways depending on the service modularization processes used. It further identifies two service modularization routes that each combine the service modularization processes in unique ways with replication as a key process to improve both standardization and customization. Practical implications - This study elaborates a framework for service modularization, which can serve as a guideline for developing service modules. It also highlights the differences between product and service modularization, suggesting that the role of service module characteristics such as standardization and customization is specific for services. Originality/value - This longitudinal case study (2008-2017) provides empirical evidence on service modularization and extends existing knowledge on service modularization processes and how they influence service module characteristics.

  • 210.
    Gudmundsson, Anna
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Arbetsmotivation: Att arbeta i dagligvaruhandel2008Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Sammanfattning

    Motivation är ett mycket övergripande begrepp. Nästan allt som vi människor gör, hur vi uppför och beter oss tros var motiverande. Vårat beteende är en verkan av den motivation som vi känner eller upplever i en viss situation, dock är det allra vanligaste beteendet oftast reflexer som vi gör (Wagner, 2003).

    Abraham Maslow är ett förekommande namn när man talar om motivation och när vi pratar om vad människan olika behov och beteenden. Han var grundaren till modellen som visar en behovshierarki hos människan, också kallad Maslows behovstrappa. Maslow menar att vi alla känner olika behov och att vi agerar efter dessa. Arbetsmässig söker man sig till kollegor för att skapa relationer, som vidare kan leda till starkare och meningsfull vänskap. Som anställd vill man känna omtanke från och gemenskap med arbetskamrater och chefer.

    Herzbergs motivationsteori handlar om motivationsfaktorer och, som han kallar det, hygienfaktorer, vilket motsvarar de lägre nivåerna i Maslows hierarki, de grundläggande behoven, trygghetsbehoven och behov av samhörighet. Särskilt viktigt är relationen mellan chefer och anställda och samspelet mellan människor även om det inte har med arbetet att göra.

    I vidare studier anser teoretiker att vänskap på arbetsplatsen är en viktig del för de anställda men även för själva verksamheten. Det vill säga att det skapas samhörighet och samspel, vilket gör arbetet mer inspirerande. Till organisationens fördel blir de anställda mer engagerade i sitt arbete och känner tillfredsställelse för sina arbetsuppgifter (Sias och Cahill, 1998). Det är våra värderingar och möjligheter som styr den inre driftkraften att vilja arbeta, det är känslomässigt nödvändigt hos varje individ att arbeta (Maccoby, 1991).

    Denna undersökning är grundat på tidigare motivationsteorier där jag har läst mig till information ur tidigare forskning. Jag har också valt att undersöka närmare hur det förhåller sig i verkligheten genom att utföra en kvalitativ metod på ett företag inom dagligvaruhandel, för att få en bra och uttömmande undersökning.

    Några av nyckelorden i resultat är gemenskap, bra stämning, öppen och klar kommunikation och en bra ledning, vilket också är en slutsats i detta arbete. Det råder en mycket god arbetsgemenskap och stämning bland medarbetarna. De har ett gemensamt tankesätt för hur en bra arbetsplats ska vara och se ut när det handlar om att motivera sin personal. De anser att det är viktigt med en bra ledning som lyssnar och bryr sig och ger möjlighet till eget ansvarstagande. Likasinnade chefer som medarbetare är en stark bidragande del till bättre arbete och inspiration för ett bättre motiverat arbete vilket är en vinande egenskap som genomskådar denna verksamhet. Det råder alltså öppenhet och en bra relation mellan dessa två parter.

  • 211.
    Gunnarsson, Jacob
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Konceptframtagning av kaffebryggare för kaffeentusiaster.2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    3TEMP was the company that provided the task. They have a vision to enter the market for home coffee equipment with a product that works as an automatic coffee machine. 3TEMP has a solution for how the machines main functions of the machine can work technically but they need a concept for the whole product. 

    The work was carried out as a project with a project plan containing a time chart, risk management, and a description of the organization and file management. The project consisted of the phases: planning, research, product specification, concept generation and evaluation, and construction and design. 

    The concept was developed with a product specification in mind. The specification is a list of user needs and preferences, and demands from 3TEMP. Information about this was collected during the research phase. The research showed that one of the most important factors, in addition to the taste of the coffee, is that the product is kept clean and fresh. Many costumers also think that it’s important to minimize the noise from the product. Also trends have been analyzed in order to create a concept that fits into many people’s kitchens. The trends suggest that tactile and natural materials are becoming more popular, and openness is desirable because it creates confidence in the product. 

    Concepts were generated by using the ideation methods: association by random words, speedstorming and brainsketching. Association by random words was used with an opportunity oriented perspective to find ways to add value to the product. Speedstorming and brainsketching was used to find ideas for the products functions and finding solutions to problems. The ideas from the ideation were combined in five different concepts. Two of these were sorted out using a relative decision matrix. One of the three remaining concepts was selected with a matrix with weighted criteria. 

    The final concept has well-known elements from the cafe industry as bent tubes of stainless steel, large grip surfaces, and visible containers. The coffee grounds container has a handle that is directly accessible from the outside of the product. This is for highlighting the container as an important function rather than hiding it like many other products do. 

    Sketches were frequently used to test ideas through the project. The selected concept has been tested with simple physical models to find appropriate forms and dimensions. After this, a more detailed physical model and a model in CAD were made. Pictures were created in CAD to show the arrangement of the components. A high resolution rendering was used to show how the product may look like in reality with real materials.

  • 212.
    Gustafson, Jacob
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Industrialization of a scale for a high pressure feeder: Concept generation, design and industrialization of a product2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis describes a project during which a new product was developed that will measure the wear of a high pressure feeder in the conventional feeding line in a paper mill. The product will also be industrialized so that it can be manufactured in smaller series. previously, wear has been measured with a metal scale where the operator read the values and documented them manually. The goal of this project was to develop the mechanical parts of a product that will automatically measure the wear distance, gather the information and present the data.

    The project followed the classic product development process that was slightly modified to fit this specific project. A pre-study of the market and the current product gathered the information needed to generate a large number of concepts. The concepts were then eliminated in order to select the final concept that was the best solution for the problem based on the requirements given by the company.

    Once the concept was chosen it was modelled using a CAD-software (Compute Aided Design). Most of the components are standard components that can be “bought off the shelf”, which means that it should not be too many special parts that will cost a lot of money and time to manufacture. The product is also IP67-classified which means that it can manage the water and white liquor (mainly sodium hydroxide and sodium sulphide) that are present in a conventional feeding line in a paper mill.

    The result consists of a description of the final product. The company have also been provided with CAD-files and a manual on how to build the product. The company have also been provided with a list of all the standard components and where to buy them.

    During the project, some of the requirements have been changed by the global development team which made the project harder and the final product is different from the initial thought. However, the goal was reached, and the company have information and concept to use as inspiration for the next generation of this product.

    The final product is a robust box that can easily be mounted onto the high pressure feeder. The lower part of the box consists of the mechanical parts that are linked to the electrical parts which are in the upper part of the box.

  • 213.
    Gustafsson, Christoffer
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Kombinerad sol- och luftvärmepumpsteknik för småskalig tappvarmvattenuppvärmning: Design och dimensionering av förångare och solfångare2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 214.
    Gustafsson, Daniel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    The Systematic Development Process Applied on a Cab Rotation Unit: Pre-study, concept generation, embodiment design, material selection and optimization2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis studies and applies the systematic development process. The process is initially described in general, creating a template for the process, and later on applied on a real case scenario to show the performance. Finally eventual advantages, drawbacks and suggestions for future improvements are given.

    The systematic development approach has been performed at Laxå Special Vehicles, who produce truck cabs and special truck chassis for Scania CV AB. The project has focused on the cabs, i.e. the Crew Cabs and the Low Entry. Crew Cabs are extended normal truck cabs, containing four doors to make additional passengers possible, suitable for fire trucks etc. Low Entry is a lowered normal truck cab, lowering the approaching height, making this cab type suitable for city applicable usage where the driver or passengers enter and leave the cab frequently. The task given was to develop the current cab rotation unit to be able to handle both cabs, which from the beginning only could handle the Crew Cabs, called CC28 and CC31. The major goal of this project has been to enable rotation of the Low Entry too.

    Five phases – pre-study, concept generation, embodiment design, material selection and optimization – were carried out. The pre-study generated a fundamental base of knowledge, according to both the systematic development process and information about the tilt. The concept generation contained a problem degradation, generation of possible solutions and finally an evaluation of these. During the embodiment design the best suited concept was described and developed in detail to allow a suitable material to be selected during the material selection phase. The optimization process consisted of investigating properties according to mechanical strength and stiffness.

    Two construction solutions to accommodate the mounting points height and length difference between the Crew Cab and the Low Entry were developed. These were a covering plate, called K4, and a mounting plate, called K100, handling the problems occurring for length and height respective. The development process is thus considered to be well operating. It generated a useful result, although possibilities for further improvements exists.

  • 215.
    Gustafsson, Filip
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Wet clutch load modeling for powershift transmission bench tests.2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this thesis a model is developed for calculating the loads on the wetclutches in apowershift transmission. This thesis was done at Volvo CE in Eskilstuna and is focusedon their 4-speed countershaft transmissions. The goal of the project is to be able tocalculate the loads automatically during the transmission tests and thus acquire increasedknowledge about what occurs during operation.The model was developed by first generating a number of concepts and then evalu-ating them to decide which one should be developed further. The chosen concept wasthen developed further and implemented into the test equipment as a calculation script.The chosen loads to model were the energy absorbed in each clutch, the coefficient offriction (COF) and the slip distance. The COF was later found to give too unreliableresults to be used in any other way than as a benchmark for how well the model wasconfigured and to see any large changes in COF.The model was validated by calculating the energy absorbed in a HTE-200 seriestransmission and comparing it to a reference calculation model. It was seen that theresults from the new model are very close to the reference result. The energy lostcalculated by the new model will be equal to 94 % of the energy lost calculated by thereference model, but only when measuring the inertia phase. The energy lost is equalto 135 % when the torque phase is included. The increasing difference is believed tobe because of an error in the reference model that means it does not cover the torquephase.

  • 216.
    Gustafsson, Fredrik
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Vem eller vad sätter priset?: En kartläggning av inköpsmarknaderna för tre metaller (Krom, Molybden, Vanadin)2011Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [sv]

    Detta arbete utförs efter en förfrågan från Uddeholm Tooling om att försöka kartlägga riskerna på inköpsmarknaden för metallerna krom, molybden och vanadin. Då detta anses vara mycket svårt föreslås här istället en kartläggning av marknaden för respektive metall, detta för att ge en bild av hur marknaden ser ut och vilka aktörer som finns.Frågorna som behandlas är var bryts, förädlas, konsumeras respektive metall? Hur varierar priserna, beskrivs priserna bäst med en random walk eller med en mean reverting stokastisk process.Det visar sig relativt snart att det är mycket problematiskt att inhämta relevant data. Speciellt då dessa metaller inte handlas öppet utan där kontrakten mellan köpare och säljare är konfidentiella. Priserna som rapporteras baseras på månatliga intervjuer med köpare, säljare och traders som utförs av branschmagasin. Detta leder till att det rapporterade priset ofta är stationärt under långa tidsperioder, det kan emellertid antas att det reella priset är betydligt mer volatilt och förändras från dag till dag. Dessa metaller kan även handlas i olika typer av föreningar och med olika renhetsgrader vilket ytligare försvårar studierna. Då det inte finns en marknadsplats där metallerna kan handlas kan även antagas att priset kan skilja sig beroende på var och av vem man köper.Detta leder till att det statistiska test som genomfördes i denna studie fick ett ofullständigt resultat, med låg korrelation mellan modell och verklighet. Det gick därför inte att avgöra om priset kan beskrivas som mean reverting. Andra studier pekar dock på att mean reversion är en mer träffsäker stokastisk process för att beskriva priserna på dessa metaller än vad än random walk är.En kartläggning av marknaden för dessa metaller visar tydligt att Kina är en signifikant aktör i samtliga fall. Då alla tre metaller främst används som legeringsämne i konstruktions- och rostfrittstål har dessa marknader stor betydelse för marknaden för respektive metall. Kina är den största konsumenten och producenten av både rostfritt och konstruktionsstål, dessutom är Kina stora vid framställningen av respektive metall. Resultatet visar på tydliga kopplingar mellan priset på respektive metall och på Kinas ökande konsumtion av stål.

  • 217.
    Gustafsson, Johan
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Från order till montering hos AP&T: En studie om förbättringsarbete2013Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This study is performed at AP&T AB in Blidsberg. They mostly build automated production lines and tools for presses. They want to have their supply chain charted. With this mapping it is possible to find deviations that stop the flow of information and material. This work will be limited to two of the company’s suppliers. The flow will end in assembly.

    To make the mapping two methods was used, functional flow chart and process analysis sched- ule. The first method will show which activities occur in each department. The second will show how much time or cost an activity demands. With this it is possible to in the end of work to analysis if the new way to work give a better result. When the mapping was done and the deviations found the study continued to sort them in a PICK-chart. This method compares the workload to the effects of improvements in each deviation. This was implemented with workers during the study to get their opinion.

    To create an improvement the method PDCA was used. This method was not used the whole way. That is because this study has a limited time frame of twenty weeks. Only a plan of action was produced with this method.

    This study will pay attention to how important it is to have the right quality of material and information. If it is wrong it created more wastage in the end of the process. It is important that each department is well informed and aware before material and information is forwarded in the production chain. If the conditions are visible in a early stage its easier to ensure the proper quality. This study has made a deeper analyse in two deviations.

    One deviation could be clear to be a result of not complete drawings that have been forwarded to suppliers. Why that had happened was because the constructions phase has not been reviewed. That even tough according to ISO 9000:2008 drawings should be review and be ensured they meet the required criteria.

    In stock it is a problem with the packing of the material to the machine. It is missing structure and procedures and that results in problem for the assemblers because it is hard to get knowl- edge about witch material exists.

    To enhance visibility of this requires an interconnection between departments. It would in this case be able to involve every department by having a representative to meet and discuss the problems and the improvement list that AP & T established. Lifting up the problems and find the root cause. If all understands the problem, it is easier to understand what it is that is wrong.

    The conclusion to be drawn is that it requires knowledge of what is right, to leave right basis. As well it’s need for measurements that provide ratios that decisions can be based on to get an un- derstanding and motivation among employees about why an improvement to be implemented.

  • 218.
    Gustavsson, André
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Konstruktion av en ensilageskärare2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 219.
    Gustavsson, Annelie
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Led till Vasaskeppets nya stöttning2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report describes a degree project of Bachelor of Science, that was commissioned by Camatec Industriteknik, as a completion of the study program in mechanical engineering at Karlstad University.The Vasa ship is a royal warship built in 1627 that today sits on keel blocks along with some supporting on the sides. Measurements and research have been showing that the ship needs a new support system because the wood is weakening and the hull is deforming. One part of the new support system is a joint for the cradle that Vasa is to be placed in. The purpose of this project is to develop one or a few concept proposals for the joint, with some constructional details.The project has followed a product development process that includes planning, specification, generation and selection of concepts and detailed construction. The process resulted in three concepts being selected and partially deepened within construction. A final concept selection will happen later, when the rest of the new support system is fully developed. A calculation model is under development as well, and when that is finished the dimensions of the joint will be specified and optimized, something that is not possible today when affecting forces still are unknown.

  • 220.
    Gustavsson, Johny
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Påverkan på lönsamhetsberäkningen för solcellsanläggningar vid förbättrad prediktering av elutbytet2015Independent thesis Advanced level (degree of Master (Two Years)), 300 HE creditsStudent thesis
    Abstract [en]

    Intergovernmental Panel on Climate Change, IPCC finds that the conditions for life on Earth are changing and that this change derives most likely to humans. The consequences claimed by other successful research initiatives to be of such magnitude that it is justified to speak of a new geological epoch, the Anthropocene. A significant driver of this change are human emissions of greenhouse gases, which to the part can be attributed to an electricity need. Photovoltaic is a technology with which electricity can be produced with significantly less greenhouse gas emissions than conventional techniques. The expansion of solar energy is thus a desirable environmental measure. The profitability of solar electricity has been an obstacle for the expansion, in particular for commercial establishments. In a sensitivity analysis performed in a study from 2014 which examines the profitability of photovoltaic (PV) plants in Sweden shows that the estimated production of electricity in the first year is the factor, second only to the initial investment cost, which has the greatest impact on the profitability calculations. In calculating the PV electricity different methods with different accuracy are used. The most accurate method involves the use of commercial software packages like PVsyst, Polysun, and PV * SOL. In a study from 2014 the accuracy of some of the above mentioned program packages was compared and notes a discrepancy in the order of seven to nine percent. According to the same report, the majority of this miscalculated power generation is attributable to the solar cell model. The solar cell model is the part of the software packages that simulate the solar cell power generation based on values of solar radiation and the solar cell temperature. There are several different solar cell models, some of which are claimed to be more accurate than others. The software package that is likely to be the most prevalent in the planning of photovoltaic plants, PVsyst, does not use the variant of the solar cell model that is claimed to be the most accurate. This thesis investigates how the implementation of a novel and more accurate solar cell model in PVsyst would affect the profitability calculations for commercial PV plants in Sweden. The work can be divided into two parts, where the first part generates input data to the other. In the first part, the more accurate solar cell model and the solar cell model that can be found in PVsyst are programmed in MATLAB. The accuracy of reconstruction of power generation based on measurement data is calculated and the difference between the solar cell models are input to the second part of the work, the profitability calculations.  The profitability calculations in this work springs from the outer conditions identified for a real case where the interested party consists of a non - private operator with a ground area available for a solar installation. The results show that the new solar cell model is two percent more carefully when calculating the electricity generation, which corresponds in order of a quarter of the total discrepancy of prediction tool PVsyst. This does not strike through in the profitability calculation to any significant extent but would the whole discrepancy be eliminated it would allow the use of a discount rate increased by about half a percent. The work also shows that commercial photovoltaic systems today can be profitable. A positive net present value was calculated based on a discount rate of five percent for a fix installation that cover the whole area. 

  • 221.
    Gydemo, Jessica
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Simulation of injection molded fiber reinforced polymers2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 222.
    Gyllensvaan, Erika
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    När två kulturer möts i samma organisation: En studie av ett japanskt företag i Mexiko2008Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Globaliseringen spelar en stor roll i dagens konsumtionssamhälle. Multinationella företag breder ut sig över världen och anpassar sig efter lokala arbetsförhållanden i hopp om att anställa kompetent personal, minska utgifter och konkurrera med både lokala och globala företag. Med internationaliseringen av företag följer även vissa svårigheter, inte nog med att kulturen inom ett företag kan skilja sig, är även ledning och arbetsstyrka från olika kulturer. Människor socialiseras in i hemlandets kultur via familj och sociala institutioner som också grundlägger värderingar, normer och beteende. Organisationskulturen har en stor inverkan på de anställda och påverkar bl a. uppfattningen av företaget, prestation och engagemang. Undersökningen syftar till att kartlägga om företagets ledarskap eller den nationella kulturen har tyngst vikt när två kulturer möts i en organisation.

    Studien baserades på en kvantitativ enkätundersökning, som syftade till att beskriva medarbetarnas syn på Toshiba de México’s organisationskultur i Ciudad Juárez, Mexiko. Enkäten utformades utifrån Hofstedes kulturdimensioner; maktdistans, individualism kontra kollektivism, maskulinitet kontra feminism, osäkerhetsundvikande samt långtids- kontra korttids inriktning. En litteraturstudie låg till grund för att förklara begreppen ”japanskt ledarskap” och ”mexikanskt kultur” samt relatera dem till rådande organisationskulturen på det multinationella företaget Toshiba.

    Enligt resultatet påverkas organisationskulturen i stort till lika delar av båda variablerna. Det visade sig att Toshibas organisationskultur karaktäriserades av en jämn grad av maktdistans, hög grad av kollektivism, maskulinitet samt osäkerhetsundvikande. Inga slutsatser kunde drags om långsiktigt- kontra kortisktig inriktning.

    Nyckelord: Organisationskultur, japanskt ledarskap, globalisering, mångfald, mexikansk kultur, Hofstede

  • 223.
    Gåård, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Damage mechanisms for tools used in applications subjected to combined impact and wear2017Conference paper (Refereed)
  • 224.
    Gåård, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Damage mechanisms for tools used in applications subjected to combined wear and impact2017Conference paper (Refereed)
  • 225.
    Gåård, Anders
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Early stages of tool damage in sheet metal forming2013Conference paper (Refereed)
  • 226.
    Gåård, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Environmental and Application Factors in Solid Friction: Friction in Metal Forming2017In: ASM Handbook vol. 18: Friction, Lubrication, and Wear Technology, ASM International, 2017Chapter in book (Refereed)
  • 227.
    Gåård, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013). Karlstad University, Faculty of Technology and Science, Materials Science.
    Galling resistance evaluation of tool steels by two different laboratory test methods for sheet metal forming2011Conference paper (Refereed)
  • 228.
    Gåård, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Influence of tool microstructure and sheet mechanical properties on galling initiation2011In: / [ed] K.C. Ludema, S.J. Shaffer, 2011Conference paper (Refereed)
  • 229.
    Gåård, Anders
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Wear mechanisms in thread joints of rock drill, a case study2017Conference paper (Refereed)
  • 230.
    Gåård, Anders
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Wear of tools sliding against carbon steel sheets2006Conference paper (Refereed)
  • 231.
    Gåård, Anders
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Karlsson, Patrik
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Krakhmalev, Pavel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Broitman, Esteban
    Linköpings universitet, Tunnfilmsfysik.
    Nano-scale friction of multi-phase powder metallurgy tool steels2015In: Advanced Materials Research, ISSN 1022-6680, E-ISSN 1662-8985, Vol. 1119, p. 70-74Article in journal (Refereed)
    Abstract [en]

    Friction is a fundamental phenomenon in tribology involving complex mechanisms between thecontacting surfaces. Measurements of friction are often made using devices with substantially largercontact area than dimensions corresponding to microstructural features of the materials. Hence, for multi-phase materials,influence of particular microstructural constituents is not resolved. In the present work, a tribometerwith a contact area in the nano-scale range was used to map friction for different types of tool steelswith different chemical- and phase composition. Owing to the small tip radius, frictionalcharacteristics of primary carbides and the steel matrix were measured and compared. Dependingon chemical composition, a difference was observed where the coefficient of friction wasapproximately twice higher for the steel possessing highest coefficient of friction, including bothcarbides and the steel matrix.

  • 232.
    Gåård, Anders
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Sarih, Rahim M.
    Karlstad Univ, Dept Mech & Mat Engn, S-65188 Karlstad, Sweden..
    Influence of Tool Material and Surface Roughness on Galling Resistance in Sliding Against Austenitic Stainless Steel2012In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 46, no 2, p. 179-185Article in journal (Refereed)
    Abstract [en]

    Transfer and accumulation of adhered sheet material, generally referred to as galling, is a major cause for tool failure in sheet metal forming. In the present work, the galling resistance of three different tool materials was evaluated in lubricated sliding against austenitic stainless steel using a SOFS tribometer. All tool materials were prepared to four different surface roughnesses, ranging from a polished surface with R (a) = 0.05 mu m to a ground surface with R (a) = 0.3 mu m. The overall best performance was obtained for polished nitrogen alloyed powder metallurgy (PM) tool steel, where galling was detected only at the highest load evaluated, 700 N. However, for both the D2 type tool steel and nodular iron, best performance was observed for the surface possessing a surface roughness of 0.1 mu m. The improved galling resistance for the rougher surfaces was related to filling of grinding scratches with sheet material during the initial stage of sliding, prolonging the development of protruding sheet material on the tools surface. Similar trend was not observed for the PM steel, which was related to width of the scratches originating from the surface preparation, in relation to tool microstructure.

  • 233.
    Hagelqvist, Alina
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Batchwise mesophilic anaerobic co-digestion of secondary sludge from pulp and paper industry and municipal sewage sludge2013In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 33, no 4, p. 820-824Article in journal (Refereed)
    Abstract [en]

    Residues from forest-industry wastewater-treatment systems are treated as waste at many pulp and paper mills. These organic substances have previously been shown to have potential for production of large quantities of biogas. There is concern, however, that the process would require expensive equipment because of the slow degradation of these substances. Pure non-fibrous sludge from forest industry showed lower specific methane production during mesophilic digestion for 19 days, 53 ± 26 Nml/g of volatile solids as compared to municipal sewage sludge, 84 ± 24 Nml/g of volatile solids. This paper explores the possibility of using anaerobic co-digestion with municipal sewage sludge to enhance the potential of methane production from secondary sludge from a pulp and paper mill. It was seen in a batch anaerobicdigestion operation of 19 days that the specific methane production remained largely the same for municipal sewage sludge when up to 50% of the volatile solids were replaced with forest-industry secondary sludge. It was also shown that the solid residue from anaerobic digestion of the forest-industry sludge should be of suitable quality to use for improving soil quality on lands that are not used for food production.

  • 234.
    Hagelqvist, Alina
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Forest industry sludge as a resource for energy recovery2009Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Forest industries produce large amounts of carbon rich sludges as by-products in their processes. Presently sludge is treated as a poor quality biofuel for co-incineration, some mills treat it solely as a disposal problem. This thesis provides an introduction to production, composition and disposal issues of sludge. It also includes a presentation of strategies for sludge handling.

    The main concern with energy recovery from sludge is connected to high content of water (50-80%). Mechanical dewatering is an energy efficient method of decreasing the water content. However, there are limitations to how far sludge can be dewatered mechanically. Thermal dewatering is sometimes required to dewater the sludge beyond these limits, in order to obtain a high quality biofuel for incineration and/or thermal gasification. It is often inefficient, from an energy point of view, to incorporate thermal dewatering in the sludge handling strategy.

    An interesting alternative to thermal processes is anaerobic digestion, which is a biological process used for energy recovery. Advantages with anaerobic digestion include biogas production, efficient treatment of sludge with high content of water and potential for nutrients recovery. The process and the kinetics of anaerobic digestion are presented.

    The aim of this thesis is to present a method for evaluating different sludge handling strategies from an energy perspective, and to further develop anaerobic digestion as a process for energy recovery from sludge. The thesis is based on two papers. Paper I presents an inclusive approach with focus on energy use and energy recovery in wastewater management, including wastewater treatment and sludge handling. Paper II explores the possibility to enhance biogas production by anaerobic co-digestion of pulp mill sludge with municipal sewage sludge.

  • 235.
    Hagelqvist, Alina
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Sludge from pulp and paper mills for biogas production: Strategies to improve energy performance in wastewater treatment and sludge management2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The production of pulp and paper is associated with the generation of large quantities of wastewater that has to be purified to avoid severe pollution of the environment. Wastewater purification in pulp and paper mills combines sedimentation, biological treatment, chemical precipitation, flotation and anaerobic treatment, and the specific combination of techniques is determined by the local conditions. Wastewater treatment generates large volumes of sludge that after dewatering can be incinerated and thus used for bio-energy production. Sludge is currently viewed as biofuel of poor quality due to its high water content, and some mills treat it solely as a disposal problem.

    Two strategies have been identified as feasible options to improve the energy efficiency of sludge management. One is drying using multi-effect evaporation followed by incineration. The other is anaerobic digestion of the wet sludge to produce methane.

    This thesis explores the energy balances of sludge management strategies in pulp and paper mills with special focus on anaerobic digestion. The first part consists of a system analysis, used to evaluate some wastewater treatment processes and sludge management, and the second part of empirical studies of anaerobic digestion of pulp and paper mill sludge. It was shown that the use of energy for aeration in aerobic biological treatment should be kept to the minimum required for acceptable quality of the processed water. Additional aeration for reduction of the generated sludge will only result in reduced energy generation in a subsequent methane generation stage. In the second part of the thesis, it is shown that anaerobic digestion is a feasible option for sludge management as it leads to production of high value biogas. Co-digestion with grass silage, cow/pig manure or municipal sewage sludge should then be used to counteract the low nitrogen content of pulp and paper mill sludge.

  • 236.
    Hagelqvist, Alina
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Granström, Karin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Co-digestion of manure with grass silage and pulp and paper mill sludge using nutrient additions2016In: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, Vol. 37, no 16, p. 2113-2123Article in journal (Refereed)
    Abstract [en]

    The purpose of this research is to evaluate how methane production is affected by the co-digestion of pig and dairy manure with grass silage and pulp and paper mill sludge at mesophilic conditions, and to assess whether methane production is affected by other factors than the now known ones, i.e., nutrient deficiency, low buffering capacity, inadequate dilution, and an insufficient activity and amount of microorganism culture. The season of grass silage and manure collection proved to be an important, previously unreported, factor affecting short-term (20 days) methane production.

  • 237.
    Hagelqvist, Alina
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Granström, Karin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Mehmood, Danish
    Improving the biogas potential of pulp and paper mills while decreasing the electricity demand for wastewater treatment2013Conference paper (Refereed)
    Abstract [en]

    Sludge formed during the necessary wastewater treatment in forest industry is currently considered to be a waste stream; rich in organic substances and poor in macronutrients, especially phosphorus and nitrogen. Previous work has shown that excessive use of electricity for aeration in wastewater treatment counteracts the potential for energy recovery in the subsequent sludge handling system, as prolonged aeration is used to degrade organic matter. This work shows that chemical oxygen demand of wastewater was not reduced further when the solids retention time was increased in aerated wastewater treatment from 2 days to 10 and 20 days respectively. The results presented here strengthen the previous conclusion that energy should only be used for sufficient effluent treatment, not for sludge reduction. A decreased need for aeration can be achieved by shortening the sludge retention time both by a decreased oxygen requirement and increased aeration efficiency. Shortened sludge retention time was shown here to increase production of biosludge as well as to increase the specific methane potential of biosludge. The results show that sludge with shorter solids retention time in the aerated treatment step gives more production of methane gas compared to sludge with longer solids retention time.

  • 238.
    Hagelqvist, Alina
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Murto, Marika
    Department of Biotechnology, Lund University.
    Anaerobic self-degradation of pig and dairy manure using co-digestion with grass silage and pulp and paper mill sludge to shorten the start-up time2013In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to find a way to shorten the start-up time of a pig and dairy manure based anaerobic digester without addition of external inoculum. Self-degradation was tested to simulate the setting of many sites where the use of external seed culture is not feasible because of the large distance to a nearest location where appropriate material can be collected. In this case study, co-digestion of pig and dairy manure with grass silage and pulp and paper mill sludge was tested using different compositions. The results showed that one tertiary mixture of 17 per cent of piggery manure, 17 per cent of dairy manure and 66 per cent of pulp and paper mill sludge resulted in a considerably shorter start-up time (about 15 days) as well as in a higher methane yield (120 ml CH4/g VS added after 44 days of batch operation) as compared to other mixtures tested. This mixture composition is recommended to start-up the full-scale process. Concentrations of ammonium of 0.4 g/l combined with slowly degradable material favoured a rapid start and efficient digestion.

  • 239.
    Haglöf, Johan
    et al.
    Karlstad University, Division for Business and Economics.
    Lindh, Jonas
    Karlstad University, Division for Business and Economics.
    Skoglund, Jimmy
    Karlstad University, Division for Business and Economics.
    Kassa arbeten?: En undersökning av hur anställda på Svensk Kassaservice upplever sin arbetssituation2006Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Vi har gjort en kvalitativ intervjustudie av hur de anställda på Svensk Kassaservice upplever att deras arbetssituation har förändrats efter omorganiseringen av Posten. Vi har intervjuat nio stycken kvinnor från olika kontor i fackförbundet SEKO:s Värmlandsdistrikt med hjälp av en halvstrukturerad intervjuguide. Vår teoretiska grund bygger på Karaseks krav- och kontrollmodell samt ett antal andra modeller för arbetstillfredsställelse. Vi har även använt oss av några psykologiska teorier för att förklara de aspekter som inte inryms i de tidigare nämnda modellerna. Intervjuerna genomfördes under oktober månad 2005 och analyserades sedan med hjälp av öppen kodning, där cirka sjuttio koncept bildades och sedan delades in i fem kategorier. Resultatet visar att de intervjuade upplever sin arbetssituation som klart försämrad efter omorganiseringen. Detta beror bland annat på att deras arbeten blivit mindre kvalificerade, att deras tjänster efterfrågas i allt mindre utsträckning och att de fått en mera otrygg arbetssituation. Vi kom också fram till att intervjupersonerna upplevde och hanterade sin situation på olika sätt och att detta påverkade deras inställning till omorganiseringens konsekvenser och sin egen situation.

  • 240.
    Hagman, Martin
    Karlstad University.
    Finns det en enkel väg till ökad lönsamhet?: En fallstudie på Hanza Mechanics för identifiering och prioritering av förbättringsförslag på tillverkningsflöde2017Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In today’s society companies facing increasingly challenges, competition and customer demands are constantly increasing. This has led to the traditional production approach no longer being sustainable. A philosophy that has been developed to meet these new types of manufacturing requirements is Toyotas Lean Manufacturing. Lean manufacturing was only meant for the car industry at first but has now been adopted by all types of manufacturing even in the public sector such as hospitals. 

    The purpose with this report is to increase the profitability in manufacturing of compressor bladethrough Lean philosophy and methods. Using Lean methods to identify unnecessary cost in the process means no big investment is required to increase profitability. 

    The goal of the report is to first identify problem areas in today’s manufacturing process and then come up with improvement suggestions enabling the company to lower their cost. 

    The work was done with an empirical data collection of qualitative and quantitative data through Interviews, observations, measurements and data analysis. The largest amount of data comes from primary data collected during the project. Secondary data such as inventory values ​​and manufacturing data were taken from the company database.

    Mapping of the current state shows that only a small part of the actual lead time is value-increasing time for the product and the time the customer is willing to pay for. Several problems and Muda were identified in the manufacturing process that causes non-value-increasing time. Based on the analyses, the most serious problem was defined as overproduction. The solution to overproduction was a Kanban system with Supermarket inventory.

    With the introduction of this new production and inventory planning system, the return on bonded capital in the internal stock would increase by approximate 127%. By releasing the bound capital, an investment for purchase of machine parts that reduces the set-time can be made.

  • 241.
    Hahlin, Mattias
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Evaluation of variations of the frictional force between a bullet and a case in a loaded cartridge2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To ensure that manufactured cartridges is safe to use, a tensile test is performed. The frictional force between the bullet and the case is required according to Normas standard to be between 15 – 75 Kg. Variations of the frictional force, with values outside of the standard had been noted by Norma Precision without understanding the cause. The aim of this report was to investigate and evaluate possible causes of the variations measured by tensile tests, difference between extreme values and to find a solution to what can be done to prevent the variations. Two different cases and three different bullets were used by request from Norma in the scope of this report. Different combinations of the bullets and cases was tested by alternating process parameter, surfaces and loading procedures. The loaded cartridges went through tensile tests to investigate differences. Bullets and cases with extreme values from the measured frictional force were chosen for further investigation in SEM and profilometer. To be able to draw further conclusions four different simulation models was created in Abaqus and different parameters was calculated. The dimensions and shape of the bullet resulted as the cause of changes of the tensile test curves. The smallest frictional force was found to differ from the largest by a change in wear mechanism from mainly abrasive ploughing to cutting and adhesion that caused transfer of material from the bullet to the case. The change in wear mechanism was found to be caused by an increased bullet diameter. The loading procedure was found to cause variations in plastic deformation on the neck of the case and damage the bottom of the bullet. The loading procedure was assumed to have the largest impact on the variations in frictional force. To minimize the variations the central axis of the case was suggested to be in line with the central axis of the bullet.

  • 242.
    Haldén, Jacob
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Analys och jämförelse av tanksystem för hydraulik2017Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report covers a full description of a project performed in collaboration with Camatec Industrial Technology AB for Outotec Sweden AB in Kil, Värmland. The project was performed as a degree project for a bachelor of science in mechanical engineering at Karlstad University, the faculty of health, science and technology.

    A big problem in hydraulic power systems is air that gets contained in the system and trapped in the oil, this leads to problems like pump cavitation, degradation of oil and dynamic problems. In a typical hydraulic system the tank works as a degasser, and there is plenty of different tanksystems with different solutions for this on the market. Outotec develops copper stripping machines which function almost completely depends on a hydraulic power system. Today Outotec is using a tanksystem called OXiStop developed by Hydac Fluid Technology AB as standard in their machines.

    The work of this project was about analyzing and comparing the functions for degassing on three different hydraulic tank systems. The goal with this project has been to draw conclusions about which hydraulic tank system out of OXiStop, Cyclone and a traditional system that is the best when i comes to degassing, by analysing and comparing the systems with a scientific approach. Hydraulic tank systems has been a heavily discussed topic recently in the hydraulics industry and there is no such comparison done by any outsider before. The only information available today is statements and results from tests that the developers has done and gone out with themselves. The purpose of this project was thus for Outotec to confirm if their current solution of choice is the best, or if it could be motivated to make a change.

    This project also included finding a suitable method for making an analysis, since this was not clear by any means from the start. Since the tank systems work very differently it was very important to find a method that would make the comaparison fair and not deceptive. Both theoretical and more practical methods were examined if they could be applied for this purpose, it was however early discovered that some empirical data would be needed to draw any final conclusions. Therefore an experimental method was chosen to do the actual analysis. Briefly the experiment involved doing compression tests in an actual specially built hydraulic system with the different tank systems connected. Then determining the bulk modulus, which is a quantity that has strong connection to how much air the oil contains. Based on the results it was possible to draw conclusions about which tank system that was most effective went it came to degassing. It turned out that the cyclone tank system was the most effective degasser and therefore it was concluded that this would be a better option for Outotec.

  • 243.
    Hallbäck, Ellen
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    CFD calculations and comparison with measured data in a film cooled 1.5 stage high pressure test turbine: With two configurations of swirlers clocking2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The gas turbine has an important role for the energy distribution due to its stability and flexibility. By increasing turbine inlet temperature (TIT) an increased thermal efficiency of the turbine can be achieved. The biggest limitation of the TIT is the material of the turbine components. To avoid this limitation, cooling is needed in the first stages of the turbine by air from the compressor. The downside of the cooling is the decrease of efficiency with excess of cooling air. To achieve an optimum cooling flow, the designing process is important. One major tool in the designing process is simulations by Computational Fluid Dynamics (CFD).

    For optimum and correct cooling design, the CFD simulations needs to accurate predict the temperature transport through the turbine. Therefore, this study focused to estimate the accuracy of different CFD methods in predicting the temperature distribution through a 1.5 stage turbine with experimental results. The CFD simulations were done by using Ansys CFX and divided into two study cases with steady RANS. One with different turbulence models;  –, Wilcox –  and SST – . The other with two different simulation approaches of interfaces for frame change; Mixing plane and Frozen rotor. All simulations included two configurations of swirlers clocking for interest of their differences within the turbine and validation of the CFD simulations; Passage (PA) and Leading Edge (LE) clockings.

    The experimental results showed a formation of gradually more uniformed temperature profile with the fluid. This could not be seen in the same extend with any of the simulations. The temperature difference between the hot and cold section with all simulations were marginally decreased in comparison of the measurements. All results with steady RANS simulations tended to over and under predict the temperatures of the hot respectively cold sections within the fluid flow through the turbine. This occurred already after the first stage guide vanes and the difference from the measurements increased after the first stage rotor. This since the steady RANS tended to under predict the mixing process through the turbine.

    Differences between the turbulence models were noticeable after the rotor blades, where the   – turbulence model predicted most mixing of the evaluated turbulence models but badly compared to the measurements. Another outcome from this study was that the frozen rotor interface with several positions of the rotor blades did not stated better results compared to mixing plane interface for temperature distribution in axial turbines. On the other hand, one simulation of one position of the rotor with frozen rotor interface could be used to simulate an approximatively similar circumferential average temperature as the mixing plane with better convergence with the disadvantage of bigger domain.

    The gas turbine has an important role for the energy distribution due to its stability and flexibility. By increasing turbine inlet temperature (TIT) an increased thermal efficiency of the turbine can be achieved. The biggest limitation of the TIT is the material of the turbine components. To avoid this limitation, cooling is needed in the first stages of the turbine by air from the compressor. The downside of the cooling is the decrease of efficiency with excess of cooling air. To achieve an optimum cooling flow, the designing process is important. One major tool in the designing process is simulations by Computational Fluid Dynamics (CFD).

    For optimum and correct cooling design, the CFD simulations needs to accurate predict the temperature transport through the turbine. Therefore, this study focused to estimate the accuracy of different CFD methods in predicting the temperature distribution through a 1.5 stage turbine with experimental results. The CFD simulations were done by using Ansys CFX and divided into two study cases with steady RANS. One with different turbulence models;  –, Wilcox –  and SST – . The other with two different simulation approaches of interfaces for frame change; Mixing plane and Frozen rotor. All simulations included two configurations of swirlers clocking for interest of their differences within the turbine and validation of the CFD simulations; Passage (PA) and Leading Edge (LE) clockings.

    The experimental results showed a formation of gradually more uniformed temperature profile with the fluid. This could not be seen in the same extend with any of the simulations. The temperature difference between the hot and cold section with all simulations were marginally decreased in comparison of the measurements. All results with steady RANS simulations tended to over and under predict the temperatures of the hot respectively cold sections within the fluid flow through the turbine. This occurred already after the first stage guide vanes and the difference from the measurements increased after the first stage rotor. This since the steady RANS tended to under predict the mixing process through the turbine.

    Differences between the turbulence models were noticeable after the rotor blades, where the   – turbulence model predicted most mixing of the evaluated turbulence models but badly compared to the measurements. Another outcome from this study was that the frozen rotor interface with several positions of the rotor blades did not stated better results compared to mixing plane interface for temperature distribution in axial turbines. On the other hand, one simulation of one position of the rotor with frozen rotor interface could be used to simulate an approximatively similar circumferential average temperature as the mixing plane with better convergence with the disadvantage of bigger domain.

  • 244.
    Hallbäck, Nils
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Girlanda, Orlando
    Tryding, J
    Finite element Analysis of Ink-Tack Delamination of Paperboard2006In: International Journal of Solids and Structures, 43(5), 899–912 (2006)Article in journal (Refereed)
  • 245.
    Hallbäck, Nils
    et al.
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Korin, Christer
    Karlstad University, Faculty of Technology and Science, Paper Surface Centre.
    Vähä-Nissi, Mika
    Seppänen, Rauni
    Laine, Christiane
    Influence of paperboard on bond formation and strength of adhesive joint2009Conference paper (Refereed)
    Abstract

    Knowledge about the glueability of fiber-based materials is limited. Factors affecting the adhesive joint between adhesive and paperboard are presented here through two cases: strength of hot melt adhesive joint and consolidation of dispersion adhesive. The hot melt joint was investigated by Y-peel testing, while shear testing was applied for dispersion adhesives. A set of supplementing tools was used to understand the adhesive joints, their development and failure. The results show, for example, the importance of paperboard roughness on the hot melt joint strength. Formation of an adhesive joint with dispersion adhesives is affected by the rheological properties of the adhesive layer and the structure and absorbation properties of the board surface. Both case studies indicate that it can actually be better to apply the adhesive first on a rough surface and the press the smooth surface on the adhesive, which is in contrast with the common practice today

  • 246.
    Hallbäck, Nils
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Tofique, Muhammad Waqas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Development of a distributed dislocation dipole technique for the analysis of multiple straight, kinked and branched cracks in an elastic half-plane2014In: International Journal of Solids and Structures, ISSN 0020-7683, E-ISSN 1879-2146, Vol. 51, p. 2878-2892Article in journal (Refereed)
    Abstract [en]

    A distributed dislocation dipole technique for the analysis of multiple straight, kinked and branched cracks in an elastic half plane has been developed. The dipole density distribution is represented with a weighted Jacobi polynomial expansion where the weight function captures the asymptotic behaviour at each end of the crack. To allow for opening and sliding at crack kinking and branching the dipole density representation contains conditional extra terms which fulfil the asymptotic behaviour at each endpoint. Several test cases involving straight, kinked and branched cracks have been analysed, and the results suggest that the accuracy of the method is within 1% provided that Jacobi polynomial expansions up to at least the sixth order are used. Adopting even higher order Jacobi polynomials yields improved accuracy. The method is compared to a simplified procedure suggested in the literature where stress singularities associated with corners at kinking or branching are neglected in the representation for the dipole density distribution. The comparison suggests that both procedures work, but that the current procedure is superior, in as much as the same accuracy is reached using substantially lower order polynomial expansions.

  • 247.
    Hammar, Martin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013). Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Körstrategi för det kommande energisystemet Falun-Borlänge: Driftanalys och framtagande av optimala styrkurvor2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    District heating is a heating alternative that deserves attention  as a  possible  key contributor in the  fulfilment  of  European  Union  energy  and  climate  goals,  the  20-20-20  goals,  to  reduce carbondioxide  emissions, improve the overall energy efficiency and increase the share of renewable energy. This is because district heating allows  industrial  excess heat recovery  and also because it presents the possibility to use otherwise unused resources such as waste and forest residue as fuel. The cities Falun and Borlänge in Dalarna, Sweden, has since 1984 and 1969 operational district heating systems, which are owned and driven by the  municipal corporations: Falu Energi &  Vatten (Falu Energy & Water) and Borlänge Energi (Borlänge Energy). When the two companies decided to collaborate  and connect their freshwater systems the decision was made to also connect the two district heating systems. The soon-to-be district heating system Falun-Borlänge will be supplied by cogeneration plants in Borlänge with waste as fuel and in Falun biofuels, but also with excess heat from the Stora Enso Kvarnsveden paper mill and the steel plant SSAB in Borlänge.Today the two systems  has different control strategies  which has to become one in order to coordinate the systems. To make this happen the two companies founded the subsidiary company Grundledningen  HB  which  is  to  be  responsible  for  the  coordination.  This  thesis  has  been conducted  with  cooperation  with  Grundledningen  HB  with  the  aim  to  develop  a  new  control strategy for the soon to be joint energy system Falun-Borlänge.The new  control strategy  was  developed  by calculating the  optimum supply temperature for different outdoor temperatures.  This was  determined by an operational analysis,  by making the problem  into  a  linear  programming  problem  and  thereafter  account  for  flow  restrictions  and temperature requirements in the system.The  result  concludes  three  different  optimal  control  strategies,  depending  on  the  ability  to control the distribution network. The  validity of the control strategies has been established through a sensitivity analysis. The developed control curves are in certain positions higher than the  ones currently used as a consequence of the coordination of the system.

  • 248.
    Hammar, Mikael
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Strategier vid avveckling av vindkraftverk - en livscykelanalys: Miljöpåverkan för vindkraftverket Lucia af Boholmen från vaggan till graven2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    År 1995 investerade kooperativet Hammarövind i ett av de modernaste största vindkraftverken på marknaden, Wind World 3700 med effekten 500 kW.  Verket togs i drift den 13 december år 1995 ute på Boholmen i Hammarö därav namnet Lucia af Boholmen.  Nu 21 år senare börjar vindkraftverket nå sitt slut och när planer för avvecklingen av vindkraftverket börjar tas fram fanns det intresse inom kooperativet att veta vindkraftverkets miljöpåverkan från vaggan till graven, en livscykelanalys. Den undersökningen utförs i detta arbete.  

    En LCA undersöker en produkts miljöpåverkan från när råvaran utvinns, tillverkning av produkten, användning och till slut hur produkten behandlas efter att livslängden har tagit slut. LCA är inget nytt inom vindkraft utan det finns ett stort antal LCA gjorda både av äldre kW verk till modernare MW vindkraftverk. Det finns en god uppfattning kring LCA resultatet för vindkraftverk, att det enbart tar ett antal månader för verket att producera den mängd energi som går åt i konstruktionsfasen och driftfasen, att koldioxidekvivalentutsläppen ligger runt 20 g/kWh.  Sedan skiljer sig olika LCA ifrån varandra beroende på olika vindkraftverks effekter, geografiska aspekter, olika antagande som har gjorts och inkonsekventa data för att nämna några orsaker.

    Det har visats sig att dessa LCA har en brist i och med att avvecklingsfasen av vindkraftverken inte undersöks. Anledningen till detta är att det saknas erfarenhet och intresset för detta moment är lågt då storskalig nermontering av vindkraftverk inte förväntas påbörjas förrän om 10 år. Men om hållbara metoder för att ta hand om vindkraftverken inte undersöks och utvecklas kommer detta att bli ett stort problem i framtiden då avfallsmängderna förväntas öka lavinartat och vindkraftverken bild som en grön energikälla kan ta skada.

    Syftet med detta arbete är att utreda hur olika avvecklingsmetoder för vindkraftverket Lucia af Boholmen påverkar resultatet för LCA.  De olika avvecklingsmetoderna som undersöktes var återvinning, fortsatt produktion på samma plats och flytt till annat land för fortsatt produktion.

    Resultatet visade att utan avvecklingsfasen tar det lite mer än 14 månader för vindkraftverket att producera den mängd energi som går åt i konstruktion och driftfasen av vindkraftverket. Intensiteten för energi hamnade på 0,063 kWh/kWh och koldioxidekvivalentutsläppen 20,52 g/kWh.

    Återvinning av vindkraft ger en energivinst mellan 157 och 193 MWh beroende på hur vindkraftbladen behandlas och de koldioxidekvivalentutsläpp som undviks ligger mellan 57,5 och 59,4 ton. Om vindkraftverket renoveras och fortsätter producera på samma plats upp till 10 år kan intensiteten för energi sänkas till 0,0368 kWh/kWh en sänkning med 41 % och koldioxidekvivalent till 12,4 g/kWh en sänkning med 39 %. Dock är chansen att få en ekonomisk lönsamhet med dagens elpris väldigt låg. Om vindkraftverket flyttas till ett annat land där stödsystem ingår kan en ekonomisk lönsamhet uppnås samtidigt som en stor miljövinst erhålls.  

  • 249.
    Hansen, Gunnar Vold
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Samarbeid uten fellesskap: Om individuelle planer i kommunalt psykisk helsearbeid2007Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    This thesis is about the implementation of individual plans in the municipal mental health sector. Persons with need for long-term and coordinated services are entitled to have an individual plan. The objectives of an individual plan are to see that the service provides user participation, individual adaptation, comprehension and coordination. The purpose of this thesis is to see if an individual plan really contributes to reaching these objectives.

    It is possible to see individual plans as a tool based on the ideology of New Public Management (NPM). As such, their basis is rational-instrumental logic. Mental health is, however, a sector recognized for different knowledge bases, indefinite relations between cause and result, and users with vague and complex needs. The reason for choosing this field of investigation is to see what happens when a sector recognized for ambiguity meets products designed upon a rational-instrumental logic.

    The study shows that it is difficult to achieve user participation and individual adaptations. The reason for this is first of all insignificant resources in the municipal sector. The service providers are mostly positive to user participation and user involvement. This is, however, difficult to achieve as long as the users do not understand the reason for an individual plan and they lack concrete goals for their lives. The prospect of making a comprehensive and coordinated service is only to a small extent dependent on individual plans. Instead it seems as if factors like how the municipality is organized, professional boundaries and insight into rehabilitation ideology and cooperation, account for how comprehensive and coordinated the service becomes. The individual plan should be administered by a service provider with overall responsibility to follow up the work (a coordinator). My results show that this coordinator usually has a very important role in assisting the users in getting the service they need. Often the plan is followed by a team meeting where the different service providers together meet the user. For some of the users, these meetings are an arena where they can influence decisions about the service.

  • 250.
    Haraldsson, Ludwig
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Vidareutveckling av eventtältet Nimbus2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The report "Further development of the event tent Nimbus" written by the student Ludwig Haraldsson describes a product development project in the course Degree project for the Bachelor of Engineering program innovation technology and design, MSGC12, at the Faculty of Health, Natural and Engineering Sciences at Karlstad University in spring 2019. Advisor for the project has been university lecturer Lennart Wihk and examiner for the project has been Professor Leo de Vin.The client for the project was Tentipi AB. Their buisness is focused on tents both for hiking and major events. The event tents are used in different settings such as markets and weddings. The tents take inspiration from the shape and construction of the Sami tent. The project aims to improve the assembly process and the construction of their smallest event tent called Nimbus. The product has problems with the tension of the fabric as the material of the fabric is stiff which can lead to the product not being mountable if one of the parts differs too much in dimensions or the fabric is sewn wrong. This means that the company wants a base construction that fits the fabric better or is adjustable. The assignment came with various requirements, for example regarding production cost and that the fabric would remain the same.Through the product development process several concepts were created. The concepts were presented to Tentipi AB and then carry out a concept selection based on these candidates. A final choice was discussed in the form of a further development of two combined concepts. The concept shares the function with an umbrella in how it spans the fabric. This means that adjustment of the tension of the fabric can occur during as well as after the assembly process. In addition, the concept otherwise follows the company's requirements and preserves its iconic form. A 3D model was created in the computer program Creo to visualize the concept and examine whether mounting is possible. Finally, a downscaled model of various hobby materials was made to prove the functionality of the clamping mechanism. Further work is needed in the form of design drawings and thorough testing on a full-scale prototype.

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