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  • 2901.
    Öhrn Sten, Niklas
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Design and development of a new invented doctor blade: Design och utveckling av nyuppfunnet kräppningsblad2014Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report contains the development and construction of a new patented doctor blade. A doctor blade is used when creping soft paper from a large rotating Yankee cylinder. At the current state the doctor blade are in use for four to six hours before it needs to be switch due to wearing, stopping the production of soft paper. The new idea is to have a very long and small blade that will slide into a fixed blade and be continuously pulled when creping paper. The company CS Production had a concept of the fixed blade but wanted to further develop it since the blade was too wide.

     

    Measurements where done with the old blade and with the old testing device to measure the pull force required to pull the blade. New concepts where made by the method of brainstorming and evaluated with an elimination matrix. Rivet joints where selected as the joining technique for the new design. The new concept contains one dominant blade that smaller parts were assembled to form the final blade. The material selected for the dominant blade and the section blade was a cold rolled stainless spring steel strip and for the middle disc the material was aluminum bronze string casted. Test on the pull force required where done with the new doctor blade in the new test rig.  FEM simulation where done on a small part of the blade to see where stresses are occurring in the blade. The FEM result showed that no stresses where on the middle discs, rivets or section blades. This is not reliable results because the small doctor blade is pushing down onto the middle discs and stresses should be occurring on the discs.  Further testing is needed to see if the blade can withstand the forces applied to it.

  • 2902.
    Ölund, David
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Konstruktion av reporterplasmider innehållande möjliga promotorregioner för kloratreduktas respektive kloritdismutas från Ideonella dechloratans2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Ideonella dechloratans is one of several isolated strains of bacteria with the ability to use chlorate in its metabolism in an anaerobic environment. This can be utilized by, for example, the paper industry where chlorate is an environmentally dangerous pollutant after chlorine dioxine bleaching. 

       Chlorate and perchlorate have been found to have negative effects in humans, animals and plants which give rise to a need for more research on improved purification methods. If the gene regulation of the enzymes that handle the breakdown of chlorate, chlorate reductase and chlorite dismutase, could be improved to work in an aerobic environment then both the purification and cost efficiency could improve.

       By inserting the promoter regions for chlorate reductase and chlorite dismutase in a broad-host-range reporterplasmid, pQlacZ-1, they can be evaluated in several different conditions and different strains of gram-negative bacteria.

       Through double cleaving of pQlacZ-1 with BamHI and EcoRI, PCR products of Clrp and Cldp from Ideonella dechloratans have been ligated into E. coli, XL-1 Blue.

       Gel extraction was found to be the most efficient method of purification before ligation but further screening needs to be performed on the transformants to ensure the efficiency of the method.

  • 2903.
    Östberg, Daniel
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Energieffektivare torkning i diskmaskiner genom ny torkmetod: Utvärdering genom praktiska försök och simuleringar2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The energy consumption is constantly increasing. The results are major environmental issues in which climate change is one of the biggest problems. Household energy consumption currently account for a significant share of the total energy consumption. Therefore it is important to improve household energy consumption to reduce household environmental impact. Appliances, which accounts for a large portion of household energy use, have a great potential for energy improvement. One example of an appliance where much energy can be saved is dishwashers.

    Dishwashers wash, rinse and dry dirty dishes. The dishwashers produced today uses less energy and water than before, when this work was done by hand. There are still more actions that can be taken to reduce the dishwasher's energy consumption. A lot of efforts are made among other things to reduce the energy consumption during the heating of the water inside the dishwasher and to reduce the energy consumed during the drying phase.

    A dishwasher where the heating occurs by a heat pump is developed by Asko Appliances AB. The heat pump takes the heat that is needed for the dishwasher from a water tank, causing the water to freeze. The drying of the dishes in this dishwasher will be done by letting the humid air inside the dishwasher out, using a fan. The air is then driven past the ice stock by making it go through an air gap, where the moisture condenses from the air on the cold surface created by the ice. The air then returns back into the dishwasher.

    In this thesis, this drying method is evaluated and compared with the technology used by Asko Appliances AB today, where the humid air is leaving the dishwasher and is brought into the room where dishwasher stands while air from the room is entering. Experiments will be performed on a dishwasher with an external ice stock. The evaluation of the drying process experiment was done using inspection. A mathematical model with an energy balance over the drying phase was built. Simulations were performed on the model and the results were verified by the experiments. With the model, the amount of water that evaporates inside the dishwasher during the drying phase was calculated.

    Results from the inspection showed that the drying method using the ice stock better performs than the drying method used by Asko Appliances AB today. High temperatures and air flow rates were found to provide a better result according to the experiments and the model. The drying is according to the model most energy efficient when the starting temperature is 70 °C, but since so much water located on the dishwasher walls is dried at that starting temperature, the in reality most efficient starting temperature is 60 °C. Then the dish is dried just as well and the energy consumption is 0.5 MJ less than when the starting temperature is 70 °C.

  • 2904.
    Östberg, Gustaf
    et al.
    Chalmers University of Technology, Gothenburg.
    Yucelen, Emrah
    FEI Company, Eindhoven, Netherlands.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Olsson, Eva
    Chalmers University of Technology, Gothenburg.
    In-Situ TEM Characterization of the Effect of Interfaces on Charge Transport in Cu (In, Ga) Se2 Thin Film Solar Cells2009In: Microscopy and Microanalysis, ISSN 1431-9276, 1435-8115, Vol. 15, p. 712-713Article in journal (Refereed)
  • 2905.
    Östberg, Linda
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Laboratory Preparation of Viscose2011Conference paper (Refereed)
  • 2906.
    Östberg, Linda
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Some Aspects on Pulp Pre-treatment Prior to Viscose Preparation2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Large amounts of carbon disulphide are consumed in the conventional production of viscose. Until a novel, eco-friendly, wood-based process for the production of cellulose textile fibres has been developed and implemented, it is important to try to find ways to improve the conventional viscose process, e.g. in terms of reducing the carbon disulphide requirement of the process. The aim of this thesis was to reduce the amount of carbon disulphide consumed in the preparation of high-viscosity viscose by pre-treating pulps with enzymes. It also aimed at investigating and linking the different measurements of reactivity, i.e. gamma number, Fock reactivity and Kw, and determining the sensitivity of the gamma number to the hemicellulose content of pulp. Reactivity was measured as Fock reactivity and gamma number. The gamma number of viscose solutions remained unchanged when an enzyme stage was used prior to the viscose process. The gamma number analysis was found to be selective not only to cellulose but also to the hemicellulosic material. It was verified that both cellulose and hemicellulose molecules in the pulp material were substituted in the viscose preparation stages, showing that the gamma number of the pulp is due to both substituted cellulose and substituted hemicelluloses. The mechanisms responsible for the Fock reactivity, or the filter-clogging value (Kw) on the one hand and the gamma number on the other, are probably not the same. It was speculated that the analysis method employed in Fock´s test and the filter-clogging value measure the results on a fibre level, whereas the gamma number measures changes mainly on a molecular level. This could explain the difference in the levels of reactivity found in this study.

  • 2907.
    Östberg, Linda
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Some Aspects of the Reactivity of Pulp Intended for High-Viscosity Viscose: Influence on the Reactivity and the Gamma Number2011Conference paper (Other (popular science, discussion, etc.))
  • 2908.
    Östberg, Linda
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Some aspects on the activation of dissolving pulps and the influence on the reactivity in a following viscose stage2013In: Cellulose Chemistry and Technology, ISSN 0576-9787, Vol. 47, no 3-4, p. 165-169Article in journal (Refereed)
    Abstract [en]

    It was found that, for a dissolving pulp, an enzymatic pre-treatment with an endoglucanase prior to viscose preparation did not change the correlation between the gamma number of the viscose dope and the carbon disulphide charge. Thus, the pulp stoichiometry, or reactivity, was not changed by an endoglucanase pre-treatment. It has nevertheless previously been found that the pulp reactivity, measured either by Fock's test or as the filter clogging value (Kw), increased for the same type of enzyme pre-treatment. Thus, the pulp reactivity seems to be influenced by the analysis method employed.

  • 2909.
    Östberg, Linda
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Some Aspects on the Reactivity of a Dissolving Pulp when used for Viscose PreparationIn: O papelArticle in journal (Refereed)
  • 2910.
    Östberg, Linda
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Håkansson, Helena
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science.
    Some aspects of the reactivity of pulp intended for high-viscosity viscose2012In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 7, no 1, p. 743-755Article in journal (Refereed)
    Abstract [en]

    The original objective of this study was to reduce the consumption of carbon disulphide in the preparation of high-viscosity viscose by pre-treating two softwood pulps with enzymes prior to the viscose stages. Reactivity can, however, be measured in different ways and the methods used in this study are Fock´s test of the pulp and the gamma number of the viscose solution prior to regeneration. It was found that whilst the reactivity of a pulp that had been subjected to enzyme pretreatment increased according to Fock´s test, it did not increase when the gamma number obtained in a standardized viscose preparation process was used. This unexpected difference that was discovered between the two reactivity tests made it difficult to analyze the impact of the enzyme stage on reactivity; the underlying reasons for the different reactivity results obtained were therefore investigated first. The conclusion that may be drawn from this investigation is that Fock´s test measures the extent to which carbon disulphide reacts with a pulp sample during a standardized test whereas the gamma number measures the resulting degree of xanthate substitution on the cellulose backbone. These two reactivity tests are thus not totally correlated. It was concluded that the gamma number was the more relevant of the two tests since it reflects the dissolution ability of a pulp in the viscose preparation, which is a very basic property of viscose. A higher gamma number also means that the coagulation time in the spinning process is prolonged; this is beneficial as it can be used to increase the tenacity of the viscose fibres. Measuring the reactivity according to Fock´s test, on the contrary, provides more dubious results as the test has no undisputed correlation to the viscose preparation process.

  • 2911.
    Östberg, Linda
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Kvarnlöf, Niklas
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    Germgård, Ulf
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering.
    The Influence of the Hemicellulose Content in Dissolving Pulps on the Gamma Number of Viscose DopesIn: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669Article in journal (Refereed)
  • 2912.
    Östberg, Martin
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Industrialisering av konsumentprodukt: Från inkommande material till färdigvarulager2014Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report examines the industrialization of a newly developed household machine on behalf of Technogarden Engineering Resources in Karlstad, Sweden. The report is a part of the final course in the Bachelor Program in Mechanical Engineering at Karlstad University and takes place in spring 2014.

    An innovator, an investor and a engineering consultant firm have through collaboration developed a new type of gruel machine. The product is in its final stage of construction and is planned to be manufactured in a production located in Sweden, autumn of 2014.

    To compete against today’s trend in outsourcing manufacturing to low cost countries for better profitability, the industrialization of the gruel machine must be done with a minimum amount of resources in order to become successful, which also describes the problem of this study. Using pre-study material in form of Lean production literature, visiting a successful production site and gathering data from involved engineers a specification was developed which describes what this industrialization must achieve and which requests can be accomplished. The specification involves the main questions such as capacity in number of gruel machines produced in a certain amount of time, ergonomics and how to achieve equal product quality.

    A comprehensive product study has been done to identify how the machine is meant to be assembled where the focus was to analyze timing, identifying item groups and assembly sequence. Six concepts on different factory layouts were created using two dimensional sketches of the actual plant chosen for the machine. The sketches show visual layouts of how the production equipment can be physically arranged in order to assemble the machine. The concepts are then assessed according to a valuation schedule in which the main factors are arranged and an engineering assessment is made of how well the different concepts satisfy these factors. From the valuation schedule the concepts obtain a score and the concept with the highest score wins.The winning concept was worked further on by developing a detailed layout using software Google Sketchup. Using the detailed layout a cost-estimation was made on the manufacturing equipment needed.

    The results of the study show that the gruel machine best is assembled together in a continuous production in form of a line layout. The assembly process is done by operators manually distributed among four stations equipped with materials via rack of items. Two of these layouts are required to meet the market demand at 20 000 gruel machines a year. An exact sizing of commodity and finished inventories could not be determined because of underdetermined suppliers and deliveries.

  • 2913.
    Östlund, Anders
    et al.
    Karlstad University, Faculty of Technology and Science.
    Suneson, Tor
    Karlstad University, Faculty of Technology and Science.
    Implementering av styrgränssnitt mellan leksaksstridsvagn och digital signalprocessor2007Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This report consists of a 15 points (22.5 ECTS) Exam Degree project at Karlstad University. The work was done on location at BAE Systems Bofors AB in Karlskoga. The company wanted to control a radio controlled toy tank from a digital signal processor (DSP). A camera connected to the DSP locates the laser point and steers the toy tank towards it.

    An interface using a programmable logic device was constructed that connects the DSP to the toy tank. The internal signals in the toy tank was analyzed and a Manchester coded signal in form of a 32-bit serial code word was detected. The code word originated from the radio controller. The control interface was built around a CPLD (Complex Programmable Logic Device) which was programmed in VHDL (Very high speed integrated Hardware Description Language). The control interface recreates the signal controlling the toy tank.

    The interface connects the toy tank to the DSP which controls the toy tank and it’s functions to the full extent. Communication between the interface and the DSP is done via a 16 bit parallel connection. 13 of the bits are data bits and the remaining 3 are control bits that are used to set up the interface. An application was integrated in the project where the DSP is detecting a laser point. Corresponding signals to the laser points position where sent to the control interface to demonstrate the function of the interface.

  • 2914.
    Östvang, Evelina
    et al.
    Karlstad University, Faculty of Technology and Science.
    Lennartzon, Ann-Kristin
    Karlstad University, Faculty of Technology and Science.
    Faktorer som påverkar upplevelser av att vara närstående till en person med cancer2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Cancer är en av nutidens stora folksjukdomar. Varje år får 10 miljoner personer runt om i världen diagnosen och år 2030 uppskattas det att 13,1 miljoner personer kommer att dö i sjukdomen. Det är inte bara den som får diagnosen cancer som drabbas utan även närstående. Syftet var att studera faktorer som påverkade upplevelser att vara närstående till en person med cancer. Metoden utgick från Polit och Becks (2012) niostegsmodell. PubMed och Cinahl valdes som databaser vid artikelsökningen. Valda artiklar granskades och analyserades enligt Polit och Becks (2012) granskningsmallar. Resultatet baserades på 11 vetenskapliga artiklar, varav fem kvalitativa och sex kvantitativa. Kategorierna som identifierades utifrån artiklarna var närståendes relation till den cancerdrabbade, kultur och religion som stöd, närståendes reaktioner, information och vardagen, vilka påvisade faktorer som avgjorde hur närstående upplevde sjukdomsprocessen. Slutsatsen visade att närstående till cancersjuka personers upplevelser av sjukdomsprocessen varierade beroende på olika faktorer. Upplevelserna framkallade både psykiska och fysiska symtom och tecken, de kunde vara både negativa och positiva. 

  • 2915.
    Özkayalar, Merdan
    Karlstad University, Faculty of Technology and Science, Department of Mechanical and Materials Engineering.
    Designförslag på framdrivning i nytt hybridfordon2014Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
56575859 2901 - 2915 of 2915
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