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  • 451.
    Nilsson, Tony
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Utbildning inom byggindustrin: Företagens upplevelse av de anställdas utbildningsbehov2007Independent thesis Advanced level (degree of Magister), 10 points / 15 hpStudent thesis
    Abstract [en]

    Undersökningen syftade till att studera relationen mellan byggindustrins arbetstagare och deras utbildning utifrån arbetsgivarnas perspektiv, vilket har utmynnade i följande frågor: Finns det någon brist på yrkesarbetare inom byggindustribranschen?; Vilka utbildningar erbjuds arbetstagarna?; Vad har arbetsgivarna för inställning till utbildning?; Hur upplever arbetsgivare inom byggindustrin effekten av utbildningsinsatser? Urvalet (n300) hämtades från Statistiska centralbyråns företagsregister och det innefattar byggindustrins verksamhetsgrenar, byggnations- och anläggningsbranschen. Det var slumpmässigt, men med en urvalsdragning av arbetsställen med minst tio anställda inom SNI 45 (byggverksamhet). Resultaten visar att det i högsta grad rådde brist på yrkesarbetare inom sektorn, vid tidpunkten för undersökningen. Att företagen inte erbjuder sin anställda utbildning i någon större utsträckning, då bara hälften av företagen som svarade erbjuder sina anställda lärlingsplatser eller yrkesteoretiska prov för erfarna arbetare. Därutöver är det endast ett fåtal företag som erbjuder fortbildning inom den anställdes kompetensområde. Företagens inställning till utbildning är oklar. Trots att en mycket stor del av företagen som svarade, dels menar att de har ansvar för utbildning av sina anställda, dels menar att det är viktigt att tillsvidareanställda har utbildning, är det bara hälften av dem som erbjuder utbildning, exempelvis i form av lärlingsutbildning eller yrkesteoretiska prov för erfarna arbetare. Däremot har företagen stor förståelse för positiva effekter som följd av utbildning, bland annat i form av ökad kvalitet på utfört arbete.

  • 452.
    Nordberg, David
    et al.
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Fridebring, John
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Produktionsprocessen: för valsservice hos Metso Paper AB2006Independent thesis Basic level (degree of Bachelor), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    In order to get a perception of the future service need for sym- and suction rolls the number of rollers that has been manufactured by Metso Paper were taken from a data base. The other roller types, for instance tambour rollers, are regarded to be unchanged. Specific information about the rollers, for instance manufacturing year and roller type has been taken from the data base. A number of diagrams has then been compiled, where the future service need for sym- and suction rolls as the service recommendation by Metso Paper for these type of rollers is eight and four year intervals. This information has been the foundation of the later part of this project when the year basis for the year 2013 was made.

    As of today there are four main activities in ship 17; grinding, assembly, testing and roller storing. All these activities require crane use and in addition to this the transports in to and out of the workshop also requires use of the overhead crane. The grinding machine is the main priority for this crane, as the grinding machine is the most expensive one and is run in five shifts, unlike other activity. The other activities are not dependant on the grinding machine as this is a separate operation, but since the grinding machine is the main priority for the overhead crane the other activities will be affected by it.

    Metso Paper Karlstad has three roller workshops (ship 16, 17 and 18) which are used to service rollers for paper mills in Sweden and in Norway. In the most recent years the need of such services has increased and the space need has become a problem in these roller workshops. The layout of the roller workshops has not been the best, as almost all of the activity is located in one of the roller workshops (number 17). This is due to the fact that this roller workshop is the only one with the crane capacity required by the heavier rollers. The purpose of this project is to examine two options in order to get the roller workshops better functioning.

    In order to estimate the two new proposals the surfaces for storing and assembly were calculated. Information such as the average surface required by a roller and the time passed in storing/assembly was measured. A work load diagram has been compiled in order to see the variation of work load in the roller workshops.

    The first proposal presented merely contains one new investment, a new overhead crane with the capacity of 2x50 tons. The moving of two roller lathes creates a new assembling surface.

    The second proposal contains an expansion of 10 meters to ship 17 and 18. This means there will be even larger surfaces for assembling and storing. As the work load varies over the year, this proposal has the capacity to handle even the most intense months, unlike proposal number one.

    By moving the two roller lathes in both the proposals it is possible to terminate the activity in ship 16, which means a more convenient production process in the roller workshop.

  • 453.
    Nordberg, Marcus
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Materialflödesanalys och layoutförslag Volvo Penta AB Varafabriken: Avdelning bearbetning, motorprov, målning och pack2013Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Detta är ett examensarbete vid Karlstad Universitet vårterminen 2013. Arbetet omfattar 22,5 hp, fakulteten för hälsa teknik- och naturvetenskap, högskoleingenjör inom maskinteknik.

     

    Arbetet har utförts på Volvo Penta AB Varafabriken i Västergötland. Volvo har ett behov att se över sin layout över fabriken och de interna materialflödena. Deras layout är gjord efter förutsättningar som rådde för 10 år sedan. En hel del förändringar har skett sedan dess och med ett nytt materialtänk som bygger på Lean-filosofin med bland annat minskade materialfasader, supermarkets och omplock.

    Fokus i arbetet ligger på att minska den tunga gaffeltruckskörningen i fabriken. Visionen Volvo själva har är att använda sig av mindre dragtruckar i så stor utsträckning som möjligt för att kunna effektivisera materialflödena. Förutom att transport är ett stort slöseri är det även en säkerhetsfråga då man inte vill ha tung körning där personal står och arbetar.

    Detta arbete har fokuserat på avdelningarna bearbetning, motorprov och måleri & pack.

     

    Första som gjordes var att ta fram en nulägesanalys. Detta för att få en koll på hur materialflödena går och hur ofta. Spaghettischema ritades upp och en frekvensanalys gjordes på hel- och halvpallar som användes på berörda avdelningar. Även önskemål om att utföra en enklare simulering framkom från Volvo vilket gjordes. Detta visade sig ge en bra uppfattning om hur truckbeläggningen ser ut angående berörda artiklar.

    En viktig del i detta skede var att identifiera sig av brister som rådde i materialflödena. Här fanns en hel del och här upptäcktes det att allt inte är layoutrelaterat. Arbetssättet var en bidragande orsak till mycket onödig körning som görs.

     

    När det kom till framtagande av ny layout kom Volvo med några starka önskemål. Att införa en ny huvudtrafikled genom fabriken var av stor vikt. Flytta på maskiner är inte aktuellt då det inte är försvarbart rent ekonomiskt. Det som kunde flyttas på var pallställage, supermarkets, omplock samt monteringen.

    Dessa önskemål togs givetvis med och tillsammans med ändrat arbetssätt påvisar detta arbete att den tunga gaffeltruckskörningen kan halveras per dag med den nya framtagna layouten (bilaga 3). Detta medför dock att vissa artiklar läggs om på dragtruckar samt att personalen tar mer ansvar och ändrar i några rutiner.

    Layouten gjordes mycket för att underlätta för dragtruckarna i framtiden då Volvo vill att de skall hantera mer artiklar internt än vad som görs idag.

     

    Ett arbete gjordes parallellt med detta med fokus på monteringslinjerna och en ny utbyggnad på fabriken av Markus Andersson.

  • 454.
    Nordenström, Erik
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Värmesystem i flerbostadshus: Kombinera fjärrvärme med frånluftsvärmepump: För ekonomisk och hållbar utveckling2017Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The overall aim of the current EU strategy Sustainable Development is to identify and develop measures to ensure that quality of life can be constantly improved, both for present and future generations. A part of the strategy is the climate targets which in the first phase extend to 2020. Its Member States shall then have reduced both their energy use and greenhouse gas emissions by 20 %. In Sweden the residential and service sector stands for 40 % of the country's energy use, they have themselves set the target to 25 % savings. New policies and improved energy efficiency will lead to completion.

    An important area of development is the heating of buildings, which accounts for 60 % of the sector's energy use. A large part of the housing stock is considered to have an energy savings potential of 20-50 %. Next to the improvement of the building envelope, the selection of heating system is of great importance.

    More than 90 % of delivered heat energy to the apartment blocks in Sweden comes from district heating. By supplementing district heating with exhaust air heat pumps, the building's energy efficiency can be increased and building owners can make a financial gain in the reduced amount of purchased energy. District heating distributers have responded to this development by changing their subscriptions, making the heating system oversized much of the year, thereby the heat pump becomes more or less redundant.

    In this case study, the heating system of an apartment building in the town of Grums (Sweden) is of interest. The exhaust air heat pump was already installed before the district heating subscription was changed. The new district heating subscription implicates that property owners have to choose which maximum base effect they can get delivered all year round. An investigation is necessary to ensure that the selected option provides a stable and low cost at different temperature.

    From the property owner's perspective, the problem is of economic nature. This study however, concentrates on the combination of district heating with heat pumps seen from the energy use and sustainability aspect. Is the heating system working in the best way today, or it is possible to find alternative modes that work better? The target with this study is to find an operational mode that primarily will reduce fuel use by 25%, secondary will lower carbon dioxide generation and cut life-cycle cost of the heat pump and thirdly will reduce the amount of purchased energy. These targets must be achieved within the annual outside temperature of 5-7 ºC.

    Currently the exhaust air heat pump is used as basic heat, warming up radiators and domestic hot water while district heating covers the deficit of the house's heating demand. Current operating mode is compared with two alternatives. Option 1 involves a change of the heat pump, to one with more power, district heating will heat the domestic hot water and will continuously work as a backup for the heat pump. In Option 2, the operation mode is altered to optimize use of the district heating base effect, the heat pump runs only when the selected base effect does not cover the heating demand. Apart from that the heat pump is replaced in the first case, no reinstallation is required for these options.

    Study calculations are made by using Microsoft Excel and duration diagrams.

    The results shows that none of the options reach the targets completely, however, Option 1 is closer considering that the primary goal (saving resources) is reached in part.

    The study shows that heating systems in apartment buildings, similar to the reference object, can be adjusted as well as the choice of base effect (district heating) in order to successfully reduce environmental effects and/or achieve financial gain. Increased use of district heating indirectly reduces carbon dioxide generation but increases resource use. Replacement of exhaust air heat pump reduces purchased energy which leads to reduced use of resources and better economy, however, will increase electricity consumption, which gives a marginal addition contribution of carbon dioxide generation.

  • 455.
    Nordin, Adam
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Översyn av bältessträckning i ViscoNip-vals2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The report was a finalization part of the thesis bachelor work in mechanical engineering at Karlstad University. A review of the ViscoNip roll belt stretch was made to Valmet. The background to the project was that the belts became resistant to wear, which meant that it was no longer necessary to adjust the machine direction. Previously the belt was moved in the machine direction to expose a new and fresh surface to even the wear. The increased quality of the belt has led to the possibility of applying a fixed side. The goal with the thesis work was to minimize the cost of the belt tension. 

    The project has gone thru a development process where project planning, product specification, concept generation, concept evaluation and layout design was included. Through a cost analysis and input from the relevant fitters and service staff, it was found that a trapezoidal screw was a highly rated solution for the head adjustment. Due to the requirement for continuous belt tension, the trapezoidal screw and a fixed end could not be combined.  As there were several advantages with the trapezoidal screw, a solution was created that was to combine a trapezoidal screw with a spring. These along with a fixed head became the winning concept.

    Before the thesis work, the cost of the ViscoNip roll belt stretch was 226 321 kr. In that price was installation, hydraulics, trapezoidal screw and displacement components.  Upon completion of the thesis, a fixed side was applied to the driving side together with a trapezoidal screw combined with a driver's spring. The estimated cost was instead 155 477 kr, a saving of 70 845 kr.

  • 456.
    Nordlind, Magnus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Westmatic platta paket: Utveckling av ett modulbaserat stativsystem2013Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 457.
    Norrman, Jonathan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Ångbesparingsåtgärder för ångsotning i en sodapanna: Effekter på elgenerering och driftparametrar på grund av minskad ångsotningsmängd i en sodapanna2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report studies the effects of reduced sootblowing steam in the recovery boiler at BillerudKorsnäs mill in Skärblacka. It has been investigated if HISS-sooting which reduces the amount of sootblowing steam can be taking into operation in the recovery boiler and what consequences will occur because of this. HISS-sooting decreases steam usage by reducing the steam flow when the lance leaves the recovery boiler.  It has been used previously in the recovery boiler, but then there were big fouling problems on in the recovery boiler and reduced soot blowing steam was not prioritized. This however was before a big renovation of the recovery boiler, therefore the conditions have changed, which can make HISS-sooting attractive again. On the mill there is a steam turbine where the high pressure steam can go through. In the steam turbine there is a outlet which soot blowing steam can be extracted from, however today this outlet is broken and the soot blowing steam is taken directly from the high pressure steam net.

     

    The purpose of this report is to investigate the mills possibility to increase their production of electricity and paper through acess to mores team because of steam savings. The objective with this work is to investigate how a reduced amount of steam for soot blowing would affect different operational parameters. It shall also look into how the fouling situation in the recovery boiler is today, what steps is necessary to bring HISS-sooting in operation and also where it could be implemented, how much the steam savings are and calculate the electricity generation that occurs with HISS-sooting.

     

    Data about the different operational parameters and different types of flows which are necessary for the calculations and the compilations is extracted from BillerudKorsnäs system Winmops and are compiled and calculated in excel. With investigation of how differentialpressure and heat transfer for different tube packages in the recovery boiler react to variations in the load on the recovery boiler, interviews with production managers and steam consumption for each individual sootblower a conclusion about the fouling in the boiler today could be made. Through interviews with production manangers, the maintenance manager and analysis of operational parameteres could the question of what steps need to be taken to get HISS-sooting into operation again and where be answered. To investigate the effects on system due to less steam for soot blowing a calculation and simulation for heat transfer, differential pressure and exhaust flue gas temperature were made for an economizer 3&4.

    A calculation of extra flue gas fan work due to the rise in differentialpressure was made. To calculate how much the steam savings could be information from another recovery boiler who use HISS-sooting was used. The electricity generation was calculated for three cases, first with soot blowing steam through the turbine, second with only HISS-sooting, and the third HISS-sooting and soot blowing steam through the turbine.

     

    The calculations and simulations showed that the effect of increased differentialpressure on the economizer increased outgoing flue gas temperature in the worst fouling case with roughly 10˚C. The interviews and examination of the different operational parameters showed that the fouling situation in the recovery boiler today is low. To get HISS-sooting operational again each soot blower need to be inspected. Each individual steam soot blowers steam consumption was approximately the same, except for two who were located in known problematic fouling areas. The extra electricity needed for the flue gas fans due to higher differentialpressure was in all cases very low when compared to the electricity generation. The electricity generation was for the first case 422 MWh/month, second 866 MWh/month and the third 1288 MWh/month.

    Altogether could HISS-sooting operate in the recovery boiler without operational disturbances. Calculations should be made on the investment cost for HISS-sooting equipment to see if the electricity generation makes up for it. The outtake for soot blowing steam should be repaired as soon as possible. If HISS-sooting is not economically feasible, reprogramming on the current sooting system should be made for a less steam consuming soot blowing. 

  • 458.
    Norstedt, Rickard
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics.
    Verktyg för tillskärning av nätisoleringsmatta: Produktutvecklingsprojekt för en effektivare och mer användarcentrerad metod för tillskärning av nätisoleringsmattor2013Independent thesis Advanced level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report covers a product development project conducted as Bachelor of Science thesis forthe Innovation & design engineer program at Karlstad University.The assignment was supplied by MMB Consulting, Kristinehamn. The purpose of this projectwas to find an alternative way of shaping wire-net insulation mats. This insulation product isused for fire and thermal insulation of technical installations. The insulation consists of stoneor glass wool with a sewn on steel wire netting on the out facing side. This netting has thepurpose to enable fastening to e.g. ventilation ducts and to provide bounding of joints. Thiswire netting makes regular methods for fitting stone or glass wool non applicable. Theexisting method for shaping wire-net insulation has flaws due to not being designed for thisapplication. These flaws include poor ergonomics, efficiency and low result quality.The objectives with this project is to find a new method that makes fitting of wire-netinsulation more efficient and safer for the user regarding personal safety and ergonomics.The work has been conducted according to the methods of the industrial product developmentprocess and the design methodology.The project resulted in a motor driven tool for shaping wire-net insulation that according to atheoretical foundation has proven to be more user adapted through being designed for goodergonomics and by offering a simpler handling. This solution is also considered to be moreefficient and to give better results than the present solution. Some correlation betweenreductions in energy losses from technical installations and the new method is detectable.

  • 459.
    Nyberg, Jesper
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Flow Distribution in Brazed Plate Heat Exchangers: A Parameter Study in COMSOL2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Lubricants and liquid cooling are used in many industrial applications to ensure reliability and longevity of machinery. Oil cooling of both electrical and mechanical applications is of interest since oil is better suited for electrical applications than water and already available in the system as a lubricant. Brazed plate heat exchangers (BPHEs) have many advantages compared to other heat exchanger types commonly used in oil cooling applications. Flow maldistribution inside BPHEs can arise with highly viscous fluids like oil. Since flow is hard to measure when plate heat exchangers are brazed together, Computational Fluid Dynamics (CFD) can be used instead.

    This study investigates parameters that could affect flow distribution inside BPHEs with the CFD-tool COMSOL Multiphysics. The study is made on three different geometries at different detail levels. The purpose of the study is to expand the knowledge about fluid behavior in BPHEs and how it affects efficiency. It was proved from the Bernoulli equation that flow velocity, gravity and Reynolds number were some parameters that could affect flow distribution inside BPHEs.

    Two simplified models were built for evaluation of viscosity, gravity and Reynolds number. A more detailed model was provided by SWEP representing the fluid domain of a full-size distribution zone model. Model validation and mesh independence study were made with expressions due to the lack of experimental data. Investigations of viscosity, gravity and Reynolds number were made through isolation and alteration of the respective parameter. The validation and mesh independence study proved the models trustworthy and detailed enough to capture the physical behavior. Small deviations from expected validation results can be explained with the assumptions and simplifications made in the process.

    Results show that flow maldistribution increases with viscosity differences between channels. Viscosity maldistribution is greater for oil than for water. It is important to consider how the fluid viscosity changes with temperature under the respective working conditions. Gravity has no effect on flow distribution as long as it acts along or opposite the main flow direction. As plate heat exchangers are generally placed vertically, gravity will not affect flow distribution. Gravity has a significant effect on flow distribution if plate packages are places horizontally. High Reynolds numbers have a positive effect on flow distribution and reduce the difference between highest and lowest velocities across the outlet. Very low flow velocities should therefore be avoided since it increases flow maldistribution.

  • 460.
    Nygren, Daniel
    Karlstad University.
    Undersökning av reservdrift och tillgänglighet för avbördningsanordningar i dammanläggningar2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The most common reasons to dam failure is a combination of high water flows and technical problems with spillway gates, caused by bad condition and deficient maintenance. Depending on the type of plant and the dam flow class, the outcomes for the society may differ considerably.

    The purpose of this study is to investigate the spillway gates on plants located in the chosen river system, inform about potential problems and what improvements that can be made on gates. This have been done by evaluating the condition of several gates and their spillway capacity and evaluate what can be done to increase dam safety.

    In order to develop a model for this, the thesis project started with a literature study, to see what RIDAS recommend and what intention it has on high dam safety. Interviews were made with experts within Fortum, in order to get a picture of what outcome they want of the thesis work. Interviews and field tests have been carried out with Bilfinger, in order to make an understanding of how the gates are maintained.

    Using information from interviews and data collection within Fortum, recommendations and improvements have been suggested to Fortum in order to maintain high dam safety.

    The results showed that there are less spillway gates on plants in flow class I, than there are in class II and it’s a relation between the number of spillway gates and backup systems that can be applied at the plants. The plants that have more gates can be equipped with more backup systems, even if the gates are of the same type at both flow classes. Plants in flow class I have less gates and lower access for backup system, even if a dam break in class I have larger effect on society. Plants in flow class I and II should be equipped with two backup system independently of each other to form redundancy. It can be enough with two backup systems that can be applied to the same gate to form redundancy. There are plants found in the study that do not meet the redundancy requirements. 

  • 461.
    Nygårds, Erika
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Experimental equipment for simulation of press nip in tissue paper machine: Prestudy and concept generation2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    During manufacturing of tissue paper, large amounts of energy could be saved with an optimized press nip. In the press nip, water is pressed out of the paper and depending on both machine and paper parameters, the dewatering effect will vary. The dewatering process is however, a complex process which is not fully understood. With the facility to simulate different tissue machine concepts in a lab-testing machine, theoretical models of the dewatering process could be tested and evaluated. Karlstad university has started a three-year project with the purpose of building a lab-test equipment for simulation of pressing of paper, and one of their partners during this project is the company Valmet AB. This master thesis was a part of this three-year project and was carried out in collaboration with Valmet AB.

    The aim of the master thesis was to determine important parameters affecting the pressing process and the requirements to be considered during the design of the lab-test equipment. The goal was also to develop some concrete concept proposals. During the literature study it was found that the most important parameters of the equipment affecting the result were nip pressure, duration time and process temperature. Paper parameters with the biggest effect on the result were compressibility resistance, flow resistance, ingoing moisture and temperature stability. After discussion with the engineers at Valmet AB, customer requirements of the equipment were determined and these, in combination with the information gathered from the literature study, were used in order to determine the product requirements of the equipment. The most important product requirements turned out to be load capacity, changeable load, process time, distance between upper and lower plate and incorporation of load cells. Several different concept proposals were developed and four of them where evaluated further. The biggest challenge in designing a lab-test equipment for simulation of pressing of paper is the short duration time in combination with high loads, and therefore, all concepts were evaluated according to this as a first step. Plenty of work still needs to be done before any of the generated concepts are finished, but three of them, Three weight, Profile and Electromagnet are seen as potential solutions.

  • 462. Nygårds, M
    et al.
    Just, M.
    Hallbäck, Nils
    Karlstad University, Faculty of Technology and Science, Materials Science. Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Tryding, J.
    A finite Element Model for simulations of Creasing and Folding of PaperBoard2005Conference paper (Refereed)
  • 463.
    Ohlson, Lukas
    Karlstad University.
    Pressade rostfria svetsrördelar2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 464.
    Oldmark, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Energieffektivisering av maskinsalsventilation: Utredning av nuläget och utvärdering av åtgärdsförslag2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Stora Enso, Skoghall’s mill is one of the largest producers of consumer board in the world and produces approximately 700 000 metric tons per year. Pulp- and paper manufacturing is an energy demanding industry and there is a large interest in lowering the energy use in different processes.The machine hall ventilation system at board machine KM8 is equipped with a heat recovery system which utilizes the excess energy from the machine’s dryer section. This energy is used to preheat the supply air to the machine hall. As a result of inaccurate control and operation, the system is not working at its optimum today and energy has to be added from a steam battery.The aim of this study is to investigate the system in its current state in terms of energy and mass balances during both the summer and the winter. The calculated energy derived from steam was used as a reference in this investigation.Based on the investigation, different proposals of action were made in order to lower the use of steam in the system. The proposals were evaluated in terms of saved energy and costs. The proposals evaluated were to change the set point of the temperature in the glycol system, change the flow in the glycol system, change the air flow in the machine hall ventilation system when the paper machine is not in use, lower the air flow in the machine hall during the winter and to install a storage tank.The result of the study showed that the steam use in the system could be lowered by 72 % which means a saving by 1.2 million SEK annually without any investment cost. De most effective proposal was to change the set point for the temperature in the glycol system so that it’s depending on the outside temperature. Installing a storage tank in order to lower the steam use is not profitable and is not proposed.

  • 465.
    Olofsson, Fredrik
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Modularisering av konstruktionsunderlag2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Volvo Buses in Säffle produces most of the customized buses within the Volvo group. As a result of the customizations additional hours in the bus assembly process for seat mounting has to be spent, and sometimes even additional design hours, during the tender process which is in 2D-CAD. The current methods and tools together with short lead time for the tenders are not accurate enough.

    The objective from Volvo is to develop a parametric seat positioning module in 3D-CAD. The module should also include parameters for construction of the bus floor.

    The parametric module has to be faster and more reliable than the current methods in 2D-CAD. Therefore the adjustments of the layout’s significant dimensions have to be done easily. The module also needs to regard safety rules and legal requirements.

    The developing of the parametric module is divided in three parts; floor module, seat positioning module and reduction of file size for the seat model. The construction of the modules will use the methodology from Top-down as main structure.

    The project resulted in three different parametric modules, one for each bus type that was analyzed during this project.

  • 466.
    Olofsson, Per
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Simuleringsmodul för energiflödesanalys av ett hybridfordons drivlina2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 467. Olsson, Emil
    Utveckling av lägesställare med tillhörande utrustning för svetsrobot: Undersökning av rotations- samt infästningsmetoder av schaber i rotationsfixtur2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This exam report includes a construction solution for further development of a schaberdressing process commissioned by Forshaga Svets & Smide. Schabrar are used in the manufacturing process of the paper industry. They are attached to a cylinder and are used to peel the paper off and also clean the cylinder. This process takes place in a very humid environment and therefor requires that the schaber is equipped with stainless material.

     

    To manufacture the schaber in stainless material would be unnecessary expensive. This problem can be resolved by covering the schaber with a stainless steel sheet by welding. This process is carried out at Forshaga Svets & Smide manually.

     

    Because of this process is done manually today it’s very time-consuming and means a lot of unnecessary work for the employees. Forshaga Svets & Smide has therefore assigned Emil Olsson the assignment to try to automate the schaberdressing process to a certain point.

     

    The purpose of this project is to shorten lead times and improve the working environment for the employees in the factory where the process occurs. This will be accomplished by automation of the rotation and the welding moments of the dressing process. The goal is therefore to develop and construct a technical solution to rotate the schaber by using Creo Parametrics and Autodesk Inventor Professional to help the welding robot with the welding process.

     

    The project has resulted in a technical solution in which simplicity and efficiency are in focus.

  • 468.
    Olsson, Erik
    et al.
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Jonsson, Christian
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Förmontering av lyftramverk2007Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    Volvo Hauler & Loader Division in Arvika produces wheel loaders which they deliver

    throughout the world. The factory which is situated in Arvika is the largest wheel loader plant in the whole world, with its 1 100 employees. The different models stretch from L60E all the

    way up to the brand new L350F, with a loader capacity from six tons up to a staggering 35.

    The assembly of the different models are divided into three different assembly lines, Small

    (L60-L90), Medium (L110-L120) and Large (L150-L220). The assembly of Heavy (L350)has just been started with an upcoming pre series.

    This examination paper gives recommendations of improvements and necessary modifications to rationalize the pre-assembly of boom units. Three different scenarios are presented in the paper. One scenario, where the work-station resembles the current workstation,

    but with a improved layout and safer working environment.

    The second scenario states a working-station where fully pre-mounted boom units should be produced, although this station requires some alterations in the construction which are mentioned in the paper.

    The last scenario is a vision of the future, where all three lines are gathered into one big line, accordingly with the visions of the company outline.

  • 469.
    Olsson, Fredrik
    et al.
    Karlstad University.
    Lindgren, David
    Karlstad University.
    Avfallshantering och kvalitetsstyrning för effektiv reducering av avfallsproduktion: En fallstudie genomförd på Cloetta Sverige AB2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Natural resources are increasingly being used and at the same time its scarcity increases. In organisations there is an excessive use of natural resources, as some are not used for their primary purpose, which can be seen as a form of waste. Production of solid waste is an area that represents unnecessary use of natural resources and at the same time entails costs for an organisation. It can be placed within internal quality deficiency costs that include defective products that are discovered during manufacturing. Reduction of defective products and solid waste is an overlap between the concepts of Lean and Green. Thus, it is of great importance to effectively reduce the occurrence of defective products and thus minimise the generation of solid waste in order to achieve a sustainable development in terms of environmental and economical concern. This study aims at investigating what deficiencies may exist in a manufacturing industry’s handling and documentation processes of produced waste, which counteracts that it can be effectively reduced. Furthermore, the purpose is to investigate how a solution can be formed taking all deficiencies into account from two perspectives, which is the system’s current design with references to theory and how well the system is implemented in practice.

    Through a case study at Cloetta Sweden AB in Ljungsbro, which works both on its own Lean-2020 initiative and with sustainable environmental development, a current state description of handling and documentation processes has been conducted on one of the factory’s production lines. Theories in waste and quality management have been used to identify deficiencies in their current processes, but also to form the basis of suggestions for improvement that shape a solution. Discovered deficiencies and designed solution hence contributes to a conclusion that answer the purpose of the study and its research questions.

    In conclusion, the three greatest deficiencies that contribute to the fact that the company cannot effectively reduce waste production are confirmed. These deficiencies are: reporting systems are designed in a way that makes it difficult to extract desired information; reporting is performed incorrectly; inappropriate measurement methods are used for weight determination of produced waste. The suggestions for improvement take all identified deficiencies into account from the two perspectives and are highlighted in analysis together with a recommendation on how they can be implemented.

  • 470.
    Olsson, Frida
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Designmetodik för hållbara förpackningslösningar: Med fokus på ekologiskt perspektiv och reducerat matsvinn2016Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report covers a process that has aimed to contribute with tools for development of sustainable packaging solutions. The project has been implemented as a Bachelor thesis for the programme in  innovation and design engineering at the faculty of health, science and technology at Karlstad university. The project has been carried out with support from Helén Williams, researcher of  environmental and energy systems.

    Today there is a lack of methods and tools for developing sustainable packaging solutions, in which food waste is taken in as an aspect. A set of three tools has therefore been elaborated from existing methods. The set can be applied in the designprocess of sustainable packaging solutions to achieve reduced food waste and environmental impact.

    The feasibility study of the project has aimed to provide information for support and included the keywords: design process, sustainable development, packaging and food waste. After the feasibility study, an analysis has been made. The intention has been to map where tools for sustainable development are missing. This would help to identify the phases of the design process with extra need of methods and tools.

    The analysis has given an opportunity to study the selected phases more thoroughly. That has led to the final result consisting of templates and guidelines for function analysis, QFD and Pugh’s method for reduced food waste. A test has been performed to put the central part, the QFD-template, into a reality perspective. The objects for the test consists of three types of milk packages.

    The tools are aimed to be used by package designers and packages technologists to facilitate their work and decisions to more sustainable solutions through reduced product waste. The goal and the prerequisite are that the tools should be easy and user friendly. If not there is a risk that they might not be used.

  • 471.
    Olsson, Jonas
    Karlstad University, Faculty of Technology and Science.
    Optimering av produktionsflöde för hydraultankar: För en bättre och säkrare arbetsmiljö2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    ”Optimizing the workflow of hydraulic reservoir tanks” is a degree project made by Jonas Olsson, student within the faculty of technology and science, during spring semester 2012. The project comprise 22,5 ECTS.

    Volvo Construction Equipment, located in Arvika, was the client in this project. The mentor at Volvo CE was Åsa Barck, and the mentor at Karlstad University was Monica Jakobsson. The examiner was Fredrik Thuvander, professor at Karlstad University.

    Volvo CE produces ten different kinds of wheel loaders. The main issues in this degree project were two different hydraulic reservoir tanks that Volvo CE assembles on various kinds of wheel loaders. The problem that the student faced in this project was that the hydraulic tank packaging, today are not safe enough. There is a risk that a tank may tumble over on today’s packaging when a mechanic moves the tank to the carrying structure.

    Much time and effort was spent on research and observations and subsequently it appeared that the workflow at the tanks assembly station wasn’t at top. By using the knowledge that the education has given the student, the goal was to optimize the workflow and prevent potential accidents from happening.

    The project resulted in a concept that contains four different parts. Stabilizing support fixtures, that strengthens the packaging. Transfer the assembly of smaller details on the bottom of the tanks to Volvo CE located in Hallsberg. Decrease the amount of non- ergonomic positions for the mechanics in Arvika by investing in lifting tables and torque wrenches. Together those different parts make a concept that solves today’s problems 

  • 472.
    Olsson, Jonas
    et al.
    Karlstad University, Division for Business and Economics.
    Broberg, Staffan
    Karlstad University, Division for Business and Economics.
    Kompetens och kompetensutveckling: en fallstudie av Schenker AB, Karltads Inspirations- och temautvecklingsdagar2006Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Med utgångspunkt i den Inspirations- och teamutvecklingskurs de anställda på Schenker AB, Karlstad åkte på utfördes en studie för att ta reda på personalens åsikter om kompetens och kompetensutveckling samt hur de uppfattade kursen och om den kan bidra till en positiv utveckling inom företaget. Studien utfördes kvantitativt i form av en enkätundersökning innehållande nio bakgrundsfrågor, 24 påståenden samt en fråga av öppen karaktär och avslutningsvis ett par rader där deltagarna fick chansen att uttrycka egna åsikter. 60 enkäter skickades ut och 46 ifyllda kom tillbaka från vilka svaren sammanställdes med hjälp av statistikprogrammet SPSS.    I den teoretiska delen behandlas begreppet kompetens både ur ett individuellt och ett kollektivt perspektiv, vilket följs upp med ett avsnitt om kompetensutveckling. Vidare behandlas områdena; den lärande organisationen, teambuilding och företagskultur.    Resultatet av undersökningen visar att personalen överlag ser kompetensutveckling som något positivt och nödvändigt, samtidigt som viljan är stor till att lära sig något nytt hos de anställda. Begreppet kompetens kan enligt svaren sammanfattas med orden kunskap, relationer, erfarenheter och utveckling. Resultatet visar även att de anställda i stor utsträckning ställer sig positiva till kursen samtidigt som de menar att den kan bidra till en positiv utveckling inom företaget.

  • 473.
    Olsson, Linda
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Rullar "krösan" ända ner till Karlstad?: En studie av företagskulturen inom Helmia.2007Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Uppsatsen beskriver företagskulturen i företaget Helmia Bil. Helmia Bil har verksamheter på flera orter i Värmland och avståndet mellan ledning och anställda är utspritt. Sjukskrivningstalen är relativt låga inom hela organisationen men speciellt låga i Sunne och Torsby. Med anledning av det uppkom mitt intreese för att studera företagskultuern inom företaget. Helmia bil ingår i en större undersökning om "långtidsfriska" företag som Karolinska institutet gör. De menar att vi ska lära av dessa företag som har låga sjukskrivningstal.

    Syftet med studien var att undersöka om företagskulturen skiljer sig åt mellan orterna Sunne/Torsby och Karlstad. Jag hade en förförståelse att företagskulturen är starkare i Sunne/Torsby där företaget en gång startade. Företaget köpte Volvohandeln i Karlstad för tio år sedan (1997). Min hypotes var att företagskulturen är starkare och mera levande i Sunne/Torsby.

    För att uppnå syftet med undersökningen har kvalitativa intervjuer gjorts. Anställda i Sunne, Torsby och Karlstad har intervjuats. Jag ville se vilka drivkrafter som finns, hur anställda upplever sin arbetsmiljö, hur kommunikationen fungerar, hur man upplever företagets ställda mål och affärsidé. Jag ville också se hur väl anställda i företaget kände till grundare och företagets värdegrund. Materialet har sedan analyserats och transkiberats med utgång från Strauss och Corbin.

    Resultatet visade att företagskulturen är starkare och mer levande i Sunne/Torsby. Olika faktorer påverkar företagskulturen. Några av dessa är: det geografiska avståndet mellan orterna, hur internkommunikationen fungerar, ledarskapet, kunskap om grundare och företagets värdegrund.

    Som bakgrund till undersökningen ligger teorier om Rutiner och Ritualer, Organisation och styrning, Makt och ledarskap och Medarbetarskap och samarbete.

  • 474.
    Olsson, Madelen
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Persson, Anna
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Personal sökes: En studie om kompetens- och kvalifikationskrav i platsannonser2008Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [en]

    There is a constant demand for employees on the labour market. A common method for organizations to find these individuals is to publish advertisements. This is a quantitative study with a qualitative complement. The purpose of this study is to examine the organizational use of the competence- and qualification terms in ads, where competence stands for the individual qualities and qualification stands for what’s needed to perform the job and its tasks. In our study, we have been given the opportunity to examine all of a municipality in Värmland’s ads from the year of 2007. We have studied and analyzed these, to create an image of the occurrence of competences and qualifications in the ads.

    The entire ads have been coded and processed in the statistic program SPSS. The result is accounted for in both text and tables to make it as lucid as possible for the reader. The study shows that qualifications and competences are demanded for in different extent, depending on what sort of profession and department within the municipality the ad is concerning. It was also shown that the ads from the municipality are characterized by a qualification perspective where Personal knowledge, which includes work experience, knowledge and education, was most frequently occurred.

    Keywords: Qualification, competence, ad, profession, department within organization,

    recruitment

  • 475.
    Olsson, Moa
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Preparation of Lignin Diesel: Experimental and Statistical Study of the Biodiesel Preparation Process from a Pulp- and Paper Industry Residual Product2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The use of fossil fuels is depleting the petroleum resources and the emissions exhausted during the use is contributing to the planets temperature rise, glaciers reciding and rised sea level etc. In a global perspective, the liquid petroleum fuels are dominating the fuel market. In the coming ten years, the use of liquid fuels is expected to grow.

     

    In this work a method of preparing a biodiesel microemulsion between petroleum diesel and kraft lignin has been examined. Lignin is a renewable by-product from the pulp- and paper industry, extracted from black liquor. In its natural appearance, lignin is not soluble in water and has to be modified to work as the hydrophilic phase in the microemulsion. The modification is achieved in a oxidative ammonolysis process. As an indication of how well the modification is performing, the amount of dissolved lignin in water were measured. The influence by the reaction time, pH-value and water content on the amount of dissolved lignin were examined in a statistical model in the software MODDE. A screening examination was performed to find the most influential factors. The MODDE model was optimized and could thereafter be used as a predictive tool and predict the outcome of responses within the experimental range. Ultrasonication was used to create the microemulsion. A stabilization test was performed by observing the created lignin diesel samples during three weeks. The operational cost of producing lignin diesel was calculated based on the chemical cost and the cost of electricity consumed during the production process.

     

    A microemulsion was not created between diesel and modified lignin, rather an emulsion was achieved. The highest amount of dissolved lignin in the oxidative ammonolysis process were 99.77 %. The most influential factor was the pH-value in the oxidative ammonolysis process. The water content also affected the amount of dissolved lignin, while the reaction time factor within its range did not affect the amount of dissolved lignin. The statistical model design, execution and predictive ability were evaluated in MODDE and given a satisfying grade. In the stability test, a separation in the bottom of the samples were observed after 0.5 h time. After one week, there was a small colour gradient in the top of one of the samples. After two weeks, the same colour gradient were observed in all of the samples. In none of the samples, a total phase separation was observed under the three weeks.

  • 476.
    Olsson, Niclas
    et al.
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Nordström, Nicklas
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Alternativ till direktel i skola2006Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Abstract

    The preschoolbuildinng Graningegården was buildt in 1974 and is today in need of a new

    heating- and ventilation system. Todays heating system, with radiators using electricity as a

    heatsource and with a control system that doesn’t work as intended, is an expensive soloution

    due to high electricity costs.

    A new system would be favourable, partly because the lack of heatrecovery in some parts of

    the ventilation system, and partly because of obsolete control system. A modern control

    system will make sure that a certain zone in the building only is ventilated when needed, that

    is, when it’s occupied.

    This would, with today energy prices in mind, have large economical benefits.

    We have with Arvika kommun as principal, carried through this project whith the purpose to

    examine the possibillitys of a construction of a modern heat- and ventilation system in the

    building. Arvika kommun is about to renovate the heat- and ventilatinsystem on

    Graningegården, and an amount of money is earmarked for this project.

    The project is initiated in collaboration with Per-Inge Andersson, our contact man at Arvika

    kommun. The building is analyzed regarding heating and ventilation loads and an energy

    balance is calculated. The results from the calculations, has helped us to find two proposals

    for the heat- and ventilation system at Graningegården.

    The first proposal has a complete mechanical exhhaust air system, and a partly mechanical

    supply air system combined with supply air through the facing of the building (F-system).

    The second proposal has a complete mechanical supply- and exhaust air system in a more

    traditionell way (FTX-system). Both these systems is meant to be combined with a boiler

    using biopellet as fuel and a hot water radiator system. The solution with some of the supply

    air trough the outer walls is also completed with a heatpump using the exhaust air as a

    heatsource.

    Both our proposoals will exceed the budget, but they will both also have a payback time at a

    few years, this because of a more efficient use of energy together with a contribution of 30

    percent of the cost at the heating system (the contribution comes from the government, and is

    meant to ease an change to a more energy efficient heating system).

    With these two proposals in mind, we would like to recommend Arvika kommun to invest in

    the F-system. This because it has a little bit lower investment costs, and it also costs a bit less

    to run.

  • 477.
    Olsson, Sofia
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Laselle, Pia
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Vem är lämplig som chef?: - en jämförande studie mellan privat och offentlig sektor2007Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [en]

    Kvinnor utgör hälften av Sveriges befolkning och speglar därigenom en stor del av samhället och borde därför finnas med i arbetslivet och skapa en jämn könsfördelning. I internationella sammanhang brukar Sverige omnämnas som ett av världens mest jämställda länder, men detta betyder inte att det svenska arbetslivet är jämställt. Jämställdhet innefattar frågor kring ledarskap, maktfördelning löner, karriär företagshierarkin osv. Offentlig sektor är den del av samhällets ekonomi som bedrivs av staten, socialförsäkringssektorn kommun och landsting. Dessa verksamheter styrs alla av en politiskvalförsamling. Den privata sektorn är den del av samhället som drivs privat och till stor del i ett vinstsyfte. Inom den offentliga sektorn är 56 % av cheferna kvinnor och 44 % män medan den privata sektorns chefer består av 22 % kvinnor och 78 % män. Trots att Sverige sägs vara ett oerhört jämställt land finns dessa skillnader och vi frågar oss varför.

    Syftet med undersökningen är att se om det finns skillnader i rekryteringsprocessen mellan privat och offentlig sektor, i anställandet av kvinnor som chefer.Vårt mål är att undersöka hur rekryteringsprocessen påverkar den rådande könssegregeringen bland chefer på arbetsmarknaden idag. Detta vill vi göra för att se om rekryteringen i sig är en orsak till att det finns skillnader mellan privat och offentlig sektor i rekryterandet av kvinnor som chefer.

    De frågeställningar vi har för avsikt att besvara är:

    • Finns det skillnad mellan privat och offentlig sektor vid rekrytering av kvinnor som chefer?

    • Är tillvägagångssättet för rekrytering avgörande för vem som söker tjänsten?

    • Hur påverkar föreställningarna och åsikterna om kvinnor och män som chefer rekryteringsprocessen, vilken skillnad finns där mellan privat och offentlig sektor?

  • 478.
    Olsson-Höök, Fredrik
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Utvärdering av inneklimatet på Alsters förskola: Termisk komfort och luftkvalitet2014Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Alsters preschool opened its operation in October 2013. Since it is so newly built, there has been no evaluation of the indoor climate. Therefore Karlstads municipality wants to carry out this study. The study focuses on thermal comfort and air quality.

    Alsters preschool is built to fulfill the Forum for Energy Efficient Buildings (FEBYs) requirements for passive houses from the year 2009. If the requirements are fulfilled, then Alsters preschool will be the first preschool in Sweden to do so. Building according to the requirements for passive houses is a relatively new method of constructing a building. Passive houses seek a well-insulated, dense and energy-efficient building. Based on this study it should be possible to determine if the energy-efficient execution is affecting the indoor climate. The results will be used to determine whether preschools can be built as a passive house in similar climates and still attain the best indoor climate classes for thermal comfort and air quality.

    To investigate the indoor climate, measurements were made over several operation days in selected climatic factors. The air temperature, relative humidity, carbon dioxide concentration and the floor temperature was monitored throughout the operation day and the measurements were logged every five minutes. In addition to these measurements the operative temperature and air movements was examined in the premises. A survey was done with the staff as a supplement to the measurements and to get the users' opinion of the indoor climate. The results from the completed questionnaires were processed by the Department of Occupational and Environmental Medicine at Örebro University Hospital.

    Three suggested operating cases were developed based on the results from the measurements and the survey to improve the thermal comfort and air quality. The energy calculation program VIP-Energy where used to simulate these operating cases. The energy calculation that was made for the contract documents was a big help when the VIP-model was developed. The energy calculation from the contract documents was also compared with the measured electricity at Alsters preschool in order to determine the credibility of simulation results.

    The measurements and the survey show that there is good thermal comfort and air quality in Alsters preschool. However, there are some factors that can be improved. Dry air and high indoor temperatures, are those factors that get the worst results. The simulations show that the adjustments that may be implemented to achieve better thermal comfort and air quality will not increase energy usage so that FEBYs requirements for passive houses are not fulfilled. This confirms that it is possible to build preschools as passive houses in similar climates and still achieve the highest indoor climate classes for thermal comfort and air quality.

  • 479.
    Osama Bin, Masood
    Karlstad University.
    Funktionell Verkstadslayout vid Aspervall Instrument AB2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report describes a project which is conceived at Aspervall Instruments AB. This project is a part of the course “degree project of Bachelor of Science in Mechanical Engineering”, MSGC17, at Karlstad University, the faculty of health, science and technology.

    The aim of the project was to present a layout proposal that could be used for a planned move of Aspervall Instruments operations from existing premises to new larger premises.

    The report consists of several different parts. The first part presents a current position analysis. With the help of the data collection (interviews, observations and study of customer orders), the cause-effect analysis and spaghetti diagram an entire picture of the company's machine park has been developed to understand the problems that exist in the current layout.

    The following part was the development of various layout proposals which solves the problems that were encountered under current position analysis. Measurement of machinery and their related equipments, measurement of the new premises and systematic layout planning have been used to map several layouts. All layout suggestions have been drafted using Microsoft Visio and Smart Draw.

    During the first screening together with the management, three layout suggestions, suggestion 2,4 and 6 were left out. Then the remaining layout suggestions 1,3 and 5 have been evaluated using two methods. The first method was about the number of reductions in transport and unnecessary movements, and the following one was about how well various proposals can solve the problems which exist within the current layout.

    Layout proposal 5 was the best result in the evaluation and is the most suitable proposal. The proposal reduces the unnecessary transport and movement with 31% and got highest points in the evaluation table. The proposal consists of comprehensive tools and material handling with a compact machine park that meets all requirements. The proposal provides a good opportunity for job rotation and transfer of skills not only in the group but also between different groups, which can lead to increased efficiency and can help to build a strong team spirit. The proposal is outlined so that moving of the machines which are planned to be replaced / purchased in the near future will not affect production.

    For continuing work, various improvement proposals have been presented as well as an evaluation has also been conducted to facilitate the management in their decision regarding what to begin with, in terms of efficiency and easy to implement. According to the evaluation tool handling and regular meetings with the staff are the two easy-to-implement enhancements and can provide effective and responsive results.

  • 480.
    Oskarsson, Kristina
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Högkvist, Lisa
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Friskfaktorer: -en studie gjord på personalen på SBAB i Karlstad2006Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Sjukskrivningar har blivit ett växande problem och företag måste värna om sin personal för att hålla den frisk. Många företag har insett vikten av att satsa på förebyggande åtgärder för att undkomma långtidssjukskrivningar. Vårt huvudsyfte med denna undersökning är att ta fram de friskfaktorer som påverkar välmående. För att göra detta har vi valt ett företag med låg sjukfrånvaro, SBAB i Karlstad.

    Tidigare forskning visar på lönsamheten av förebyggande åtgärder framför rehabilitering. För att kartlägga vart insatserna bör göras är det angeläget för företag att vara medvetna om vad som håller personalen frisk. Enligt forskning har många faktorer påverkan på välmående, sociala relationer och motion är två av dessa.

    Resultatet grundar sig på en kvalitativ studie där sex intervjuer bland personalen på SBAB genomförts. De faktorer som enligt undersökningen har visat sig ha störst betydelse för personalens välmående är organisationskultur, socialt stöd, arbetsvillkor, fysisk aktivitet och återhämtning. I resultatet framkom även att individens personlighet och inställning påverkar hur de olika friskfaktorerna upplevs.

  • 481.
    Ottosson, Anders
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Nilsson, Lars
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    A mathematical model of heat and mass transfer in Yankee drying of tissue2017In: Drying Technology, ISSN 0737-3937, E-ISSN 1532-2300, Vol. 35, no 3, p. 323-334Article in journal (Refereed)
    Abstract [en]

    Final dewatering in the production of dry creped tissue is performed by Yankee drying, which includes hot pressing followed by simultaneous contact and impingement drying. The present study models Yankee drying and compares simulation results to the data obtained from trials on a pilot tissue machine. It advances models published previously by the representations developed for the transport of heat in the pressing stage and for the heat transfer involved in the dehydration of the cylinder coating spray. The model predicts an average specific drying rate within 4% in the range of the experimental data used.

  • 482. Ottosson, Anders
    et al.
    Nilsson, Lars
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013). Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Analogies between heat and mass transfer for estimation of air humidity2013In: Sixth Nordic Drying Conference NDC 2013, Copenhagen, Denmark, 2013Conference paper (Refereed)
  • 483.
    Ouakad, Hassen M.
    et al.
    King Fahd University of Petroleum and Minerals, Saudi Arabia.
    El-Borgi, Sami
    Texas A&M University, Qatar.
    Mousavi, Mahmoud
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Friswell, Michael I.
    Swansea University, UK.
    Static and dynamic response of CNT nanobeam using nonlocal strain and velocity gradient theory2018In: Applied Mathematical Modelling, ISSN 0307-904X, E-ISSN 1872-8480, Vol. 62, p. 207-222Article in journal (Refereed)
    Abstract [en]

    This paper examines the length-scale effect on the nonlinear response of an electrically actuated Carbon Nanotube (CNT) based nano-actuator using a nonlocal strain and velocity gradient (NSVG) theory. The nano-actuator is modeled within the framework of a doubly-clamped Euler–Bernoulli beam which accounts for the nonlinear von-Karman strain and the electric actuating forcing. The NSVG theory includes three length-scale parameters which describe two completely different size-dependent phenomena, namely, the inter-atomic long-range force and the nano-structure deformation mechanisms. Hamilton's principle is employed to obtain the equation of motion of the nonlinear nanobeam in addition to its respective classical and non-classical boundary conditions. The differential quadrature method (DQM) is used to discretize the governing equations. The key aim of this research is to numerically investigate the influence of the nonlocal parameter and the strain and velocity gradient parameters on the nonlinear structural behavior of the carbon nanotube based nanobeam. It is found that these three length-scale parameters can largely impact the performance of the CNT based nano-actuator and qualitatively alter its resultant response. The main goal of this investigation is to understand the highly nonlinear response of these miniature structures to improve their overall performance.

  • 484.
    Oumar, Kifilo
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Utvärdering av ett värmepumpsystems prestanda till en HWC-tvättmaskin: Med fokus på fläktvarvtal och köldmedieflöde2014Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    This report was performed in order to evaluate a new technological measure and focuses generally on a heat pump system to a HWC-washing machine. The client is Asko Appliances AB, a company well known for its environmentally friendly products. The goal of this study was to improve the energy efficiency of a washing machine by combining a heat pump device to the heater of the wash water, in order to reduce the energy consumed for heating the water. Besides reducing the energy consumption in heating the water, the washing machine was required to meet low noise and short operating time specifications. For that purpose, nine trials in three test series have been carried out. In each of those trials, airflow has been combined with the refrigerant flow and the energy consumption measured. The comparison of the results shows that the energy efficiency is the highest when the flow rates of both the air and the refrigerant are low. Further, the energy consumption in terms of electricity used in heating the water has been lowered by 71% in comparison to a refernce washing machine using no heat pump device. The paper also discusses possible improvement actions related to this technological mesure. This technological measure can be applied on HWC-washing machines and can replace conventional electrically heated washing machines.

  • 485. Paiola, M
    et al.
    Gebauer, H
    Edvardsson, Bo
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Service Research Center. Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Business Administration.
    Service Business Develpment in Small- to Medium-Sized Equipment Manufacturers2012In: Journal of Business-to-Business Marketing, ISSN 1051-712X, E-ISSN 1547-0628, Vol. 19, no 2, p. 33-66Article in journal (Refereed)
  • 486.
    Pedro, Simon
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Automation, attachment of lids in ventilation ducts2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis has been written to design and develop an automated solution which can attach protection lids in the ends of the ventilation ducts as they are manufactured.

    A danish factory within the group are using a solution which enables the manufacturing process of ventilation ducts to be automated which Lindab also want to implement in their Swedish factories. However, as the conditions which the ducts are required to be delivered in are much tougher in Sweden, lids are attached on the ends of the duct to prevent contamination. As these lids are manually attached there is no financial incentive for Lindab to automate the manufacturing process of the ventilation ducts as the operators still have to remain to attach the lids.

    The thesis covers the product development of automating the lid attachment. Through different elimination matrices and evaluation against the requirement specication was a final concept chosen. In addition to product development, a background investigation was also performed to examine for what reasons the automation was desired but also what advantages in production efficiency an automatic solution provides.

    The automation was solved by constructing a mount station where every duct dimension are fixated in the same radial axis which facilitates the process for the expanding mechanical grippers to attach the lids in the pipes. The lids are picked up by the grippers from conveyor belts where they are stored in stacks. In order to enable the lids ability to stack as well as improve their shape rigidity, the lids were redesigned with the addition of a radial reinforced rib pattern which extends over the entire bottom as well as a heel placed in the middle of the mantle surface which is in contact with the duct.

  • 487.
    Pernefur, Micael
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Produktutveckling och prestandatest av ett vattenvärmedrivet torkskåp: Jämförelse mellan tre utvecklade versioner av ett vattenvärmedrivet torkskåp2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Electricity consumption is a globally increasing problem caused by the high share of electricity produced in coal power plants. These contribute to high carbon emissions when only about 1/3 of the heat generate electricity and the remaining 2/3 of the heat cools off. Combined heat and power plants (CHP) have high efficiency because they use the residual heat for domestic heating. The CHP plant often use fuels from renewable resources, giving them a lower carbon footprint, but are also depending on the heat demand. If electric powered products such as drying cabinets convert to heat powered products more environmentally friendly electricity will be produced by CHP plants, which can supplant electricity, produced from coal power plants and reduce carbon emissions. Karlstad University has therefore, in collaboration with Nimo-verken AB and Asko Appliances AB developed a prototype of a water heated drying cabinet. The prototype has been tested, evaluated and further developed into a competitive product to market. Three versions (A, B and C) of the cabinet were tested with water flow temperatures of 55 and 80 °C and was also tested half-and fully loaded. Version A's low air flow gave long drying times and poor energy efficiency (SMERTot). Version B had a better flow and therefore gave better results in drying times and efficiency (SMEREl and SMERTot). The redevelopment of Version C mounted a larger fan which markedly increased airflow in the cabinet. This version gave the best stability, drying time and SMERTot. Both the drying times and SMER Tot was better than any comparable drying cabinet on the market. The energy efficiency, proportion of electricity used for drying (SMER El) gave values several-fold higher than any comparable drying cabinets on the market. The water heated drying cabinet produced, with the conditions above, 4% of the carbon emissions for a comparable, electric-powered cabinet. To study how to stop a drying process at the right time temperature measurements were made at the exhaust air from the cabinet. Strong correlation was found for the selected water flow temperatures and versions.

    The conclusions were that the drying process in a drying cabinet can be stopped in time by continuous measurement of exhaust air temperature. The relatively cool supply air temperatures obtained from the hot water also manage to dry textiles quickly and efficiently if only the air flow is large enough. This also means that carbon emissions were low. The goals were achieved but there is still great development potential in flow optimization and heat loss reduction of the water heat powered drying cabinet.

  • 488. Persson, Björn
    Utredning av behovsstyrt ångtryck på lågtrycksnätet: Maximerad elproduktion vid Stora Enso Skutskärs Bruk2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    One of the global sub-goals states that rehabilitation and adaptation of industrial infrastructure is important for making industries more sustainable, with more efficient use of resources by year 2030. Increased energy prices, strict environmental requirements, new control instruments for efficient end use of energy have created an increased desire to reduce energy use and related energy costs. Sweden has a goal of increasing the renewable electricity production by 18 TWh by year 2030 using the control instrument electricity certificate.

    Energy efficiency can be achieved at: the different kinds of processes in the mill, assistant systems, and heat and electricity supply (power generation). In this study, the main focus will be on power generation. The paper and pulp industry uses large amounts of different energy types in all processes in the factory. In this study, the focus is on the energy type steam. One of the basic requirements that a cogeneration system needs to follow is the steam pressure requirements of all the steam-consuming processes in the mill. In this study, all the steam-consuming processes on the low-pressure network have been investigated.

    The study is limited to the month of September year 2018. The system boundaries start from the recovery boilers and the bark boiler, and then the steam path is followed through the grid and ends at the steam consuming processes.

    The method is divided into two main parts: In the first part, a calculation model of the zero system was constructed. The second part is a study of the pressure requirements of the steam consuming processes on the low-pressure side.

    It is possible to demand control the turbine. The evaporation processes control the demand system. The other processes that limiting the lowest pressure are considered to be: The feed water tank and the receiver (at drying machine 8).

    The low-pressure network can be reduced from 3.2 to 2.92 bar (over pressure) without any applications. The pressure may be further reduced if a technical investigation is carried out over the turbine. The minimum design pressure of the steam consuming processes is considered 2.5 bar (over pressure). The pressure limit:

    • 2.92 bar (over pressure) gave a cost reduction of 2.64 million SEK per year.
    • 2.5 bar (over pressure) gave a cost reduction of 4,69 million SEK per year.

    Optimized operation is considered an approval measure for the allocation of electricity certificates. 8982 electricity certificates will be given if it is 100 percent allocation of electricity certificates of the turbines generated electricity with a design reduction of the pressure to 2.5 bar (over pressure). The certificates then corresponds to an income increase of 2.25 million SEK per year.

  • 489.
    Persson, Edvin
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Enineering.
    Krabba: Automatisk pallkragsmontering2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The company Goodtech Solutions AB has developed a prototype. This prototype is a machine that automatically can assemble pallet collars on pallets with the help of a robot. The prototype needs to undergo some improvements and this work focus on the unit that handles the pallet collar during the assembling. This unit is called crab because of its design. The objective of this work is to accomplish the improvements and the purpose is to be a basis for all the improvements that the machine could undergo before a market release.

    To assemble a pallet collar the crab locks the pallet collar after it’s received from the robot. Then it bends the hinges and mounts the pallet collar onto a pallet. The crab’s main problems are the adjustments before handling the pallet collar and to correct the crab’s position in relation to the outer collar before assembling. This is because all adjustments are in relation to the center of the crab and that the crab pushes out the four corners when locking the pallet collar. To bend the hinges the crab uses a method that’s similar to a quick hammer stroke and this method is considered uncontrolled. A customer requirement emerged during the project. The customer requirement was that the machine should handle the bigger Volvo L pallet collar in addition to the EUR pallet collar.

    Because the crab should handle two different sizes of pallet collars the new concept would be for a new design. Therefor the work was limited to only include the crab. The attachment of the crab to the structure and the drive during assembly were excluded. Because of these restrictions the new crab must have the same movements as the present crab to collaborate with the rest of the machine.

    In the new concept two sides of the crab are fixed, one long and one short side, and the other two are variable. The two variable sides push outwards in a linear direction to lock the pallet collar. With two sides fixed all adjustments can relate to their corner as it is an origo. The crab remains in this fixed position because of the origo but the outer collar can adjust to this origo. This new concept appears to be better for adjustments because of the origo and that only two sides can vary. To bend the hinges there are four units in each corner. The units bend the hinges with a linear movement and an anvil so the forces can be absorbed locally. These units can vary their positions to handle both the EUR pallet collar and the Volvo L pallet collar. The linear movement to bend the hinge is considered stable.

    During the design of this concept the choices of components, material, material dimensions are based on rough estimates and oversizing due to the machine being a prototype. The crab was designed foremost with parts and profiles in construction steel. Hydraulic cylinders were used to bend the hinges. Pneumatic cylinders and ball rail systems were used to lock the pallet collar and other movements.

    This new concept and its design have improved the crab and extended its functionality. Therefor the objective and purpose of this work is considered to be achieved. Work still remaining is more precise estimates of material dimensions and components. The attachment in the structure and the drive during assembling should be looked over to make sure the crab is compatible with the rest of the machine.

  • 490.
    Persson, Joakim
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Industriventilation i textilproduktion: Energieffektivisering och påverkan på inneklimat2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Klässbols Linneväveri AB is one of Sweden's few linen weaving mills located in Klässbol, Värmland. The company engages in production and sales of linen products, such as tablecloths, towels and curtains. As part of the work to reduce the company's energy use research on the production premises ventilation system, that require large amounts of energy, can be streamlined without adverse impact on production.

     

    Energy consumption is associated with the size and the heating of airflows. The purpose of this report is to investigate the possibilities for improving the ventilation system's function in favour of the production process, energy efficiency of system operation as well as meeting occupational health and safety requirements.

     

    Industrial ventilation in textile production places high demands on the relative humidity of the air due to its importance to the raw material, in this case the durability of linen. In addition to handling the relative humidity of the air, the ventilation system must also handle the airborne textile dust generated by machines and looms.

     

    After a survey of the operations, the ventilation system and the present indoor climate, balance calculations have been conducted to develop alternative airflows based on the requirements of the production process and the working staff.The survey finds that the problem during winter is to achieve the desired level of relative humidity (RH) which is limited due to lack of isolation in the ceiling. At present RH is 50%, which is considered to be too low. Furthermore, the mapping shows that the dust concentration in the production sites does not exceed specified limit values.

     

    The results of the calculations show that current RH in the production sites can be achieved with reduced airflows. This also means reduced energy consumption and reduced operating costs by SEK 22,6 thousand per year. To increase RH in the production sites to desirable 75% or to achieve the highest RH that the ventilation system can deliver, airflows need to be increased for most of the year. Improved indoor climate for the production process involves thus increased energy consumption and increased operating costs by SEK 46,9 thousand per yearrespectively SEK 57,5 thousand per year.

  • 491.
    Persson, Mats
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School.
    The Construction of Support and Opposition: A Study of an Attempted Higher Education Merger2015Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This study focuses on support and opposition in an attempted merger between three Norwegian university colleges.  The university colleges that took part in the merger process were Buskerud University College, Vestfold University College and Østfold University College, all three located in the south-east part of Norway. The study takes its point of departure in the fact that the merger process was terminated before a decision to merge was reached. It aims to describe the two discourses of support and opposition, and explain change in discursive practices from support to opposition.

    The thesis is divided into three parts. In the first part the conceptual framework used in the analysis is presented, as well as the area of mergers in higher education and methodological aspects.  Four conceptual pairs are used to analyse the merger process; support/opposition, idea/operationalisation, outwards/inwards and modern/traditional. The second part is constructed as a play with acts presenting the merger process in a chronological order where the conceptual pairs are used to describe and explain discursive practices. The third and final part focuses on general insights into the construction of support and opposition in the terminated merger process.

    The study shows that the use of different discursive practices evolved into antagonism between the three university colleges leading to the termination of the merger process. Supporting the idea to merge in order to achieve university status was not enough to support the merger if the operationalisation of how the merger process was to be conducted, and how the merged organisation was to be constructed led to a disadvantageous power position.  In addition, discursive practices of support and opposition were conditioned by discourses of the education market and academic drift.

  • 492.
    Persson, Rebecca
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Working Life Science.
    Kan ord skapa work-life balance?: Hur frihet, flexibilitet, förnyelse, förståelse bidrar med balans mellan arbetslivet och privatlivet2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna undersökning är att djupare undersöka vad fenomenet work-life balance innebär i en svensk kommun. I teoriavsnittet behandlas delar om hur det såg ut tidigare på arbetsmarknaden och Sveriges lagar angående föräldraledighet. Det ges en förklaring till work-life balance begreppet som är förmågan att hantera både arbetssfären och icke-arbetssfären utan att någon av sfärerna tar över eller sätter press på den andra. Vårdkapital är även ett viktigt begrepp i denna undersökning och det står för omsorg, att ta hand om andra som t.ex. barn, äldre eller sjuka familjemedlemmar. Vidare beskrivs flexibilitet då det är ofta en bidragande faktor för att nå balans mellan hemmet och arbete. Andra delar som behandlas är organisationens påverkan på den anställda, att medarbetaren bör ses som en tillgång och organisationen bör underlätta för medarbetaren att ha ett liv utanför arbetet som följs av företagskultur. Även obalans som ofta bidrar till stress och utbrändhet tas upp vilket och teoridelen avslutas med obetalt arbete och genus på arbetsmarknaden. För att kunna få en djupare kunskap om ämnet har jag valt att använda sig av en kvalitativ metod, varav intervjuer, för att ge en större flexibilitet i frågorna kring ämnet work-life balance. Urvalet kom att bestå av 7 medarbetare på Sunne kommun som alla hade barn i olika åldrar. Det utfördes även en pilotintervju för att höja validiteten i undersökningen, att rätt ämne undersöktes. Även etiska aspekter har tagits hänsyn till i denna undersökning. Resultatet kom att bestå av fjorton delar där de första fyra består av Sunne kommuns honnörsord som är frihet, flexibilitet, förnyelse och förståelse i förhållande till de intervjuade. I resultatet finns även delar om vårdkapital, om arbetsdagen räcker till, sociala relationer mellan kollegor, om arbetssfären eller hemmasfären någon gång tar över. Avsnittet avslutas med de intervjuades reflektion över kollegornas balans, deras egna balans och Sunne kommun som arbetsgivare. Resultatet visar medarbetare som uppfattar en balans vilken sker utifrån att de själva ser till att balansen fungerar och samtidigt att Sunne kommun bidrar med faktorer som skapar hanterbarhet.

  • 493.
    Persson, Tomas
    et al.
    School of Technology and Business Studies, Dalarna University.
    Riedel, Jochen
    School of Technology and Business Studies, Dalarna University.
    Berghel, Jonas
    Becksell, Ulf
    School of Technology and Business Studies, Dalarna University.
    Win, Kaung Myat
    School of Technology and Business Studies, Dalarna University.
    Emissions and deposit properties from combustion of wood pellet with magnesium additives2013In: Journal of Fuel Chemistry and Technology, ISSN 1872-5813, Vol. 41, no 5, p. 530-539Article in journal (Refereed)
    Abstract [en]

    This work studies the amount of gaseous and particle emissions and deposits on heat exchanger surfaces in a boiler fired with commercially available pellets and with pellets primed with magnesium oxide and magnesium hydroxide. The combustion experiments were performed on a residential boiler of 20 kW. Substrates placed in the heat exchanger was analysed with SEM-EDX-mapping to evaluate the chemical composition of the deposits. The results show that particle emissions (PM 2.5) using the additives increased by about 50% and the mass of the deposits in the flue gas heat exchanger (excluding loose fly ash) increased by about 25% compared to the combustion of pellets without additives. The amount of additives was found to be eight times higher than the amount of the main alkali metals potassium (K) and sodium (Na) which leads to the assumption that the additives were overdosed and therefore caused the problems reported. The SEM analysis of the substrates placed in the flue gas heat exchanger indicate that the deposits of sodium (Na), potassium (K), chlorine (Cl) and sulphur (S) decrease using the additives. If this was due to the expected chemical reactions or due to the loose fly ash covering the substrates after the test, could not be determined in this study.

  • 494.
    Persson, Zara
    et al.
    Karlstad University, Division for Business and Economics.
    Svensson, Ida
    Karlstad University, Division for Business and Economics.
    Långtidsfriskhetens mysterium: - En studie kring vad som ökar sannolikheten för att vara långtidsfrisk2006Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Sammanfattning

    I den politiska debatten har det under de senaste åren förts en ständig diskussion kring den ökade graden av sjukskrivningar som den svenska arbetsmarknaden visar. I diskussionen riktas fokus, i många fall, på de sjuka arbetstagarna, hur sjukskrivningar kan förebyggas samt hur man kan få dem att återvända till arbete efter en längre sjukdomsperiod. I den här undersökningen har vi dock valt att rikta fokus på de som aldrig är sjuka, de långtidsfriska. Vi kan identifiera dem i olika branscher, åldrar och yrkesgrupper, de som dag efter dag, år efter år går till arbetet. Genom att urskilja friskfaktorer hos de långtidsfriska finns en förhoppning om att kunna överföra dem till den mindre friska delen av arbetsgruppen. Långtidsfriskhet är beroende av ett flertal omständigheter i vår närmiljö. Däribland de arbetskrav vi utsätts för och vilken grad av egenkontroll samt socialt stöd vi upplever i arbetet. Den kan också bero på hur vi tar hand om den egna hälsan och sköter vår kropp.

    Syftet med undersökningen om långtidsfriska var att undersöka vad som ökar sannolikheten för att en person ska vara långtidsfrisk. Vi var intresserade av de bakomliggande faktorerna, de som gör att vissa personer är mer friska än andra.

    För att kunna besvara ovanstående syfte har studien utförts med en kvalitativ metod. Vi har genomfört 8 stycken intervjuer på vårdbiträden och undersköterskor i Arvika kommun samt tagit del av aktuella teorier inom ämnet.

    Resultatet visar på en rad påverkande faktorer i och utanför arbetet. För att förtydliga det lilla extra som krävs för att uppnå långtidsfriskhet har vi delat in de identifierade faktorerna i friskfaktorer och långtidsfriskfaktorer. Faktorerna vi har funnit är bland annat balans i livet, tid för återhämtning samt en hög grad av socialt stöd. Faktorerna kan vi se som mer eller mindre lätta att påverka som individ eller arbetsgivare. Sammanfattningsvis kan vi i alla fall säga att det inte finns något entydigt recept för långtidsfriskhet att följa, vilket såklart hade varit önskvärt från alla inblandade parter.

    Nyckelord: långtidsfrisk, friskfaktorer, trygghet, balans.

  • 495.
    Petersson, Oskar
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Utveckling av rotationsenhet för hantering av storsäck: Ett produktutvecklingsprojekt2018Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report concerns a degree project that has been completed as a completion of the Bachelor of Science in Mechanical Engineering at Karlstad University. The customer of the project was Goodtech Solutions AB in Karlstad. The goal of the project has been to develop an additional unit to one of Goodtech’s existing systems that fill and handle bags with bulk material. The underlying problem was that in some cases would be desirable to get the bag rotated 90 degrees.

    The project has followed the product development process with phases such as requirement specification, concept generation and layout design. A variety of different concept have been generated and evaluated, where the most beneficial was taken for further development, which ultimately led to the result.

    The design proposal that has been developed is based on the use of an electric cylinder and two pneumatic cylinders. The design is adapted to handle the variation of load that can occur and is easy to implement in the existing system when desired.

    In theory, the design can solve the underlying problem with regards to strength, capacity and cycle time. The estimated cost of design proposal is approximately 62 000 SEK.

  • 496.
    Pettersson, Helen
    et al.
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Kleine, Elida
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Matchning av arbete och arbetskraft: En jämförande studie mellan privat och offentlig arbetsförmedling2007Independent thesis Basic level (degree of Bachelor), 10 points / 15 hpStudent thesis
    Abstract [sv]

    Uppsatsen behandlar matchningsprocessen hos tre olika bemanningsföretag i jämförelse med den offentliga arbetsförmedlingen. Syftet med uppsatsen är att studera hur handläggare på de olika organisationerna arbetar med matchning, det vill säga att sammanföra arbete och arbetskraft. I studien redogörs också för några av de faktorer som kan påverka handläggarnas arbete.

    Frågeställningarna är; Hur arbetar handläggarna för att lyckas med matchningen? Hur arbetar organisationerna med verktyget coaching? Hur påverkar den organisatoriska utformningen handläggarnas matchningsarbete och anser handläggarna att de yttre faktorerna såsom allmänhetens attityd eller politiska beslut påverkar matchningsarbetet? För att få svar på frågeställningarna genomfördes en kvalitativ studie med sex djupintervjuer.

    Intervjuguiden baserades på teman som utvecklades parallellt med teori- och emperibearbetning. I analysen användes verktyg som inspirerats av grounded theory såsom kodning.

    Teoridelen är uppbyggd i kronologisk ordning där det inledningsvis redogörs för organisationernas historiska bakgrund och verksamhet. Därefter följer ett avsnitt som behandlar organisationernas huvuduppgift vilket är matchning. Teoridelen innehåller sedermera aktuella organisationsteorier, dagens förmedlingsverksamhet och arbetsgivares val av förmedling. Dessutom presenteras verktyget coaching och en rapport om samverkan mellan organisationerna.

    Resultaten av studien visar att det finns en skillnad hos organisationerna i kontakten med arbetsgivare vilket kan bero på organisationens struktur och politiska beslut. Ytterligare en skillnad i arbetet med matchningen är friheten för bemanningsföretagen att välja kandidater medan den offentliga arbetsförmedlingen måste ta emot alla, vilket påverkar matchningsarbetet. Gällande verktyget coaching framkom att förmedlarnas (handläggarnas) intresse för verktyget avgör frekvensen av användandet oberoende av organisationstillhörighet. Vidare visar resultaten att organisationsuppbyggnad påverkar handläggarnas arbete. Slutligen framkom att arbetssökanden tenderar att bli uppdelade mellan de två olika förmedlingsverksamheterna, då ombytessökande i större utsträckning återfinns hos bemanningsföretagen och de öppet arbetslösa hos den offentliga arbetsförmedlingen.

  • 497.
    Pettersson, Natalie
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Investigation of material removal techniques for residual stress profile determination on induction hardened steel2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The residual stress profile is a major factor on the fatigue life of components that are subjected to cyclic loading. In order to measure these stresses x-ray diffraction (XRD) is commonly used. The penetration depth of x-rays is limited for this method and thus, it must be combined with material removal to determine in-depth stress profiles.At SKF Manufacturing Development Center (SKF MDC), where the work for this thesis was carried out, the current layer removal method is restricted to a depth of 0.5 mm. Consequently, an additional method of material removal is necessary to obtain information at greater depths. The purpose of this thesis was to investigate possible material removal techniques that can be implemented with XRD measurements.

    Two different material removal techniques were studied; electrochemical etching and milling in combination with electrochemical etching. The electrochemical etching equipment was developed at SKF MDC prior to this thesis but needed further testing and validation.

    The residual stress profiles of induction hardened cylinders were studied using the two different removal techniques combined with XRD measurements and the results were compared with stresses measured by Electronic Speckle Pattern Interferometry (ESPI) with hole drilling. In addition, the results were compared with simulations performed at SKF MDC India. It was concluded that both the material removal methods could be successfully combined with XRD measurements. However, for practical reasons the methods should be refined before being implemented on a regular basis. Unfortunately, poor correlation between XRD and ESPI measurements were obtained due to reasons not fully understood.

  • 498.
    Pettersson, Niklas
    et al.
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Eriksson, Nils
    Karlstad University, Division for Engineering Sciences, Physics and Mathematics.
    Småskalig elproduktion i Arvika2006Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    Arvika Fjärrvärme AB, a district heating company from Arvika, today cover 74 % of their total energy production with biofuel wich runs a 16 MW bioler giving process water at saturated liquid state.

    In recent years Vaporel AB has introduced a new tecnique that gives an external generation of steam after boilers. The concept is built on an adiabatic pressure drop of the saturated liquid in a so called Flashbox which makes a small part of the liquid to evaporate. The generated steam is lead into a turbine where electricity is in a conventional manner.

    The purpose with this rapport was to do a basic study for the specific system at Arvika where it’s possible to see the potential production of electricity that follows an installation of a flasbox.

    The final goal was to introduce an economic analysis of a flashox installation at given conditions.

    To reach our goals we have created a model in Excel where we used the given conditions at Arvika Fjärrvärme to do our calculations. The model has been tested at three different states, of process water returning to potboiler, to be able to decide the optimal operation for the system at present.

    The studies have resulted in a pressure of the processwater at 14,5 bar (at) and a pressuredrop to 9,5 bar (at) in the flashbox. The condenser pressure is set to 0,5 bar (at) what is equal to 81 ˚C. Energy to the district heating net is produced in the condenser and heat exchanger.

    The result of our calculations clearly shows that to reach the highest turbine-efficiency as possible and gain the largest profit the highest process-waterflow possible should be used.

    That means 70 kg/s after present conditions.

    At the highest boiler efficiency the turbine will produce 694 kW. At this state the water that returns to the boiler will be at temperature 148 ˚C (14, 5 bar).

    Totally during a year the production of electric energy could reach 2, 47 GWh/year. The energy used by the pumps will increase with 0,21 GWh over the year at that state.

    Included all economic factors this will generate a profit of 0, 97 million (SEK)/year.

    To make an installation of a flashbox system more profitable an increased generation of electricity have to be made. This could be done by an installation of new pumps to be able to run the process-water at a larger flow to increase the amount of steam made in the flashbox.

  • 499.
    Phan, Kong
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Innovativa modulmöbler för barn: En möbellösning som möter barnens fantasi och motorikutveckling genom lek och byggande2014Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This project assignment is done on behalf of the innovator Ludmila Kompaniets. The project is included in the compulsory for the course MSGC12 - Degree of Bachelor of Science in Innovation and Design at the Faculty of health, nature and Engineering Sciences at Karlstad University.

    The innovator Ludmila Kompaniets with many years experience as a preschool teacher found a need for children to have their own privacy in preschool environment.

    The anchoring made to the curriculum highlighted the lack of work on the physical environment in preschools.

    Ludmila Kompaniets with her idea are intent to help children stimulate their senses and further develop their motor skills indoors during their pre-school years. For this to be possible, she used the children's curiosity and playfulness. The idea is based on a group of innovative modulation furniture that will allow children to independently use their creativity in building furniture with safety.

    Interviews together with observations in preschools in Karlstad district have been analyzed and showing rather poorly results.

    The concept generation took place in two rounds, the first concept generation session was with people who have influence in the profession with children. Second session was with a group of children, this to observe how children think in concrete form. Both sessions yielded a number of concept solutions, which are then eliminated and evaluated. At the final step through spiderweb chart the selection appointed to the selected concepts that are best suited to the product specification and according to the project owner's intentions.

    The concept solution’s simple but abstract forms are challenging to the target group’s different senses, senses that the children need to outbreak in order to learn and be stimulated. The solution provides the children to separate from stress -related causes such as noise and large groups. The concept solution also provide modulation that challenge children's motor skills.

    Material proposal for the concept is applicable and is already prepared on the market for the target group, the manufacturing method is simple and has a relatively low cost. Cost of materials and manufacturing should be examined in a larger extent.

    A full-scale prototype should be tested with the target audience in order to investigate how well the solution meets the issue.

  • 500.
    Pluto, Malin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Tank Shell Design According to Eurocodes and Evaluation of Calculation Methods2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Tanks are storage vessels for liquids. They can have different appearances; some are short and wide, others are tall and slim, some are small, others are large. In this thesis a tank of 6 m in both diameter and height has been used to obtain numerical results of the stresses in the tank. Tanks are most often thin-walled with stepwise variable shell thickness with thicker wall sections at the bottom of the tank and thinner at the top. Since they are thin-walled they are susceptible to buckling and there are conditions the shell construction must meet. The conditions that has to be met are determined by the laws and regulations that govern tank design. The National Board of Housing, Building and Planning (Boverket) is the new Swedish authority for rules of tank design and the Eurocodes are the new family of standards that should be followed. Sweco Industry AB is the outsourcer of this thesis and wants to clarify what rules that apply now when the Eurocodes are to be followed. The thesis project has produced a calculation document in Mathcad for tank shell design according to the Eurocodes with stress calculations according to membrane theory and linear elastic shell analysis. This thesis has also produced a comparison of stresses calculated using membrane theory, linear elastic shell analysis and finite element method (FEM). The comparison has been made for numerical results given for an arbitrarily designed tank wall. The loads acting on the tank included in the description were self-weight, internal and hydrostatic pressure as well as wind and snow loads. The loads were described in accordance with the Eurocodes. Some assumptions had to be made where the standard was vague or deficient in order to make calculations by hand possible. For example, the wind load had to be described as an axisymmetrically distributed load rather than an angularly varying. The stresses in the tank wall were calculated through creating free-body diagrams and declaring equations for force and moment equilibrium. The loads and boundary conditions were set in a corresponding manner in the FEM software Ansys as in the calculation document in order to obtain comparable results. When compared, the stress results calculated with membrane theory and FEM were quite similar while the stresses calculated with linear analysis were a lot larger. The bending moments were assumed to be too large which make the results of the linear analysis dominated by the moments. The arbitrarily dimensions set for the tank did thus not fullfill the conditions when linear analysis was used but did so for membrane theory and FE-analysis. Since the results calculated with membrane theory were very close to FEM in most cases, even without expressions for local buckling, it was assumed to be an adequate method in this application. Expressions for local buckling are although needed for the meridional normal stress. The conclusions of the results obtained are that membrane theory is a simple and adequate method in most cases. Linear analysis thus becomes redundant since it is more complicated and more easily leads to faulty results. Furthermore it cannot be used for higher consequence classes than membrane theory. FEM, with a computer software such as Ansys, is although the most usable calculation method since it can conduct more complicated calculations and is allowed to be used for all consequence classes.

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