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  • 301.
    Brännstam, Johanna
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Molnbaserade CAD-system2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When working with computer-aided design (CAD), are you tired of CAD-files being saved, where you cannot access them? Are you tired of having to sit at a specific computer to work on your drawings? Recently, cloud-basedCAD software started to become available and companies, such as Umeå-based Sigma Industry East/North, consider settling on a standard cloud-basedor cloud-connected program to facilitate the work of theirconsultants. In this bachelor thesis, two of the most promising cloud-basedCAD programs, Autodesk Fusion 360 and Onshape, are selected among the available CAD software, and investigatedwith respect to parameters such as price, program handling, user education, folder structure and archiving, and the ability to perform finite element method (FEM) analysis. In order to substantiate the evaluation, the two programs are exposed to a test. A generic work piece is modeled and drawn that allows comparison regarding multicomponent modeling, sheet metal, drawings, threads and text engraving. It was found that, in general, the two different programs perform similarly, but that they differ in at least three important aspects: price, ability to work offline and user ability. Fusion 360 costs half the price of a comparable Onshape license, can be payed monthly, does not require internet, and allows the cost FEM functions to be individually adapted. Basedon this analysis, Fusion 360 is recommended as cloud-based CAD-software for small-to medium-sized companies.

  • 302.
    Brännström, Emil
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Underlag för kommunal- respektive gårdsbaserad biogasanläggning.2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 303.
    Brännvall, Evelina
    et al.
    Luleå Tekniska Universitet.
    Nilsson, Malin
    Luleå Tekniska Universitet.
    Sjöblom, Rolf
    Luleå Tekniska Universitet.
    Skoglund, Nils
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Kumpiene, Jurate
    Luleå Tekniska Universitet.
    Effect of residue combinations on plant uptake of nutrients and potentially toxic elements2014In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 132, p. 287-295Article in journal (Refereed)
    Abstract [en]

    The aim of the plant pot experiment was to evaluate potential environmental impacts of combined industrial residues to be used as soil fertilisers by analysing i) element availability in fly ash and biosolids mixed with soil both individual and in combination, ii) changes in element phytoavailability in soil fertilised with these materials and iii) impact of the fertilisers on plant growth and element uptake.

    Plant pot experiments were carried out, using soil to which fresh residue mixtures had been added. The results showed that element availability did not correlate with plant growth in the fertilised soil with. The largest concentrations of K (3534 mg/l), Mg (184 mg/l), P (1.8 mg/l), S (760 mg/l), Cu (0.39 mg/l) and Zn (0.58 mg/l) in soil pore water were found in the soil mixture with biosolids and MSWI fly ashes; however plants did not grow at all in mixtures containing the latter, most likely due to the high concentration of chlorides (82 g/kg in the leachate) in this ash. It is known that high salinity of soil can reduce germination by e.g. limiting water absorption by the seeds. The concentrations of As, Cd and Pb in grown plants were negligible in most of the soils and were below the instrument detection limit values.

    The proportions of biofuel fly ash and biosolids can be adjusted in order to balance the amount and availability of macronutrients, while the possible increase of potentially toxic elements in biomass is negligible seeing as the plant uptake of such elements was low.

  • 304. Buga, Sergei
    et al.
    Blank, Vladimir
    Bagramov, Rustem
    Dubitsky, Gennadii
    Fransson, Åke
    Umeå University, Faculty of Science and Technology, Applied Physics and Electronics.
    Serebryanaya, Nadejda
    Sundqvist, Bertil
    Umeå University, Faculty of Science and Technology, Physics.
    Thermal stability of superhard and ultrahard fullerites2000In: Proceedings of International Conference on Engineering and Technological Sciences 2000 (ICETS-2000), vol. 1, Beijng: Chinese Academy of Engineering: New World Press , 2000, p. 505-511Conference paper (Refereed)
    Abstract [en]

    The thermal stability of superhard and ultrahard carbon phases synthesized from C60 and C70 fullerenes under pressure in the range 9.5-13 GPa and temperature between 670 and 1850 K was investigated by DSC in the range 260-640 K and TGA up to 1200 K. Endothermal heat effects were observed with a peak maximum just below 540 K, a temperature characteristic for breakdown of (2+2) intermolecular links in dimers, 1D and 2D polymers. Exothermal effects, starting from 380 K, were observed for the first time in polymeric fullerenes. These effects are attributed to relaxation processes and to breakdown of other types of intermolecular bonds.

  • 305. Buga, Sergei G.
    et al.
    Blank, Vladimir D.
    Dubitsky, Gennadii A.
    Serebryanaya, Nadejda R.
    Fransson, Åke
    Umeå University, Faculty of Science and Technology, Applied Physics and Electronics.
    Wågberg, Thomas
    Umeå University, Faculty of Science and Technology, Physics.
    Sundqvist, Bertil
    Umeå University, Faculty of Science and Technology, Physics.
    Synthesis of superhard 3D-polymeric C60 fullerites from rhombohedral 2D-polymer by high-pressure-high-temperature treatment.2003In: High Pressure Research vol. 23, issue 3: Proceedings of the 40th European High Pressure Research Group Meeting on Advances in High Pressure Research (EHPRG'40), London: Taylor & Francis , 2003, p. 259-264Conference paper (Refereed)
    Abstract [en]

    Rhombohedral C60 polymer was subjected to high-pressure-high-temperature treatment at P =13 GPa, T =620-1620 K. After quenching, crystalline and disordered structures with densities in the range of 2.1-2.9 g cm-1 were obtained. The structures of the samples have been investigated by powder X-ray diffraction and Raman scattering. DSC analysis showed a transformation of the polymeric structure into monomeric on annealing in the range 400-640 K. The temperature dependence of the electrical resistance of samples with disordered structure was measured in the range 2.5-300K. For different samples, the conductivity was proportional to T1/2, T3/2, T4 and exp(-1/T1/4).

  • 306. Buga, Sergei G.
    et al.
    Blank, Vladimir D.
    Fransson, Åke
    Umeå University, Faculty of Science and Technology, Applied Physics and Electronics.
    Serebryanaya, Nadejda R.
    Sundqvist, Bertil
    Umeå University, Faculty of Science and Technology, Physics.
    DSC study of annealing and phase transformations of C60 and C70 polymerized under pressures in the range 9.5 - 13 GPa.2002In: Journal of Physics and Chemistry of Solids, ISSN 0022-3697, E-ISSN 1879-2553, Vol. 63, no 2, p. 331-343Article in journal (Refereed)
    Abstract [en]

    C60 and C70 fullerenes polymerized under pressures between 9.5 and 13 GPa and temperatures between 670 and 1850 K were investigated by differential scanning calorimetry (DSC) in the range 240–640 K. Endothermal heat effects were observed with a peak maximum just below 540 K, a temperature characteristic for breakdown of (2+2) intermolecular links in dimers, 1D and 2D polymers. Exothermal effects, starting from 380 K, were observed for the first time in polymeric fullerenes. These effects are attributed to relaxation processes and to breakdown of other types of intermolecular bonds such as common four-sided rings and (3+3) interlinks.

  • 307. Buga, Sergei G.
    et al.
    Fransson, Åke
    Umeå University, Faculty of Science and Technology, Applied Physics and Electronics.
    Serebryanaya, Nadejda R.
    Sundqvist, Bertil
    Umeå University, Faculty of Science and Technology, Physics.
    Blank, Vladimir D.
    Dubitsky, Gennadii A.
    Dissociation energy of 3D-polymeric C60: Calorimetric study and structural analysis2001In: Electronic Properties of Novel Materials - Science and Technology of Molecular Nanostructures: Proceedings of the XV International Winter School on Electronic Properties of Novel Materials, Kirchberg 2001, Melville, NY: American Institute of Physics , 2001, p. 49-53Conference paper (Refereed)
    Abstract [en]

    Annealing of 2D- and 3D-polymeric C[sub60] fullerene obtained under pressures of 9.5 and 12.5 GPa and temperatures of 670 and 770 K has been investigated by DSC in the range 240–640 K. An endothermal heat effect was observed with a peak maximum just below 540 K, a temperature characteristic for breakdown of (2+2) intermolecular links in dimers, 1D and 2D polymers. Exothermal effects, starting from 380 K, were observed for the first time in polymeric fullerenes. These effects are attributed to relaxation processes and to breakdown of other types of intermolecular bonds such as common four-sided rings and (3+3) interlinks.

  • 308.
    Bugaytsova, Jeanna A.
    et al.
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Björnham, Oscar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Swedish Defence Research Agency, 906 21 Umeå, Sweden.
    Chernov, Yevgen A.
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Gideonsson, Pär
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Henriksson, Sara
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Mendez, Melissa
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Sjöström, Rolf
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Mahdavi, Jafar
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. School of Life Sciences, CBS, University of Nottingham, NG7 2RD Nottingham, UK.
    Shevtsova, Anna
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Ilver, Dag
    Moonens, Kristof
    Quintana-Hayashi, Macarena P.
    Moskalenko, Roman
    Aisenbrey, Christopher
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Bylund, Göran
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Schmidt, Alexej
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Åberg, Anna
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Brännström, Kristoffer
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Koeniger, Verena
    Vikström, Susanne
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Rakhimova, Lena
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Hofer, Anders
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Ögren, Johan
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Liu, Hui
    Goldman, Matthew D.
    Whitmire, Jeannette M.
    Åden, Jörgen
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Younson, Justine
    Kelly, Charles G.
    Gilman, Robert H.
    Chowdhury, Abhijit
    Mukhopadhyay, Asish K.
    Nair, G. Balakrish
    Papadakos, Konstantinos S.
    Martinez-Gonzalez, Beatriz
    Sgouras, Dionyssios N.
    Engstrand, Lars
    Unemo, Magnus
    Danielsson, Dan
    Suerbaum, Sebastian
    Oscarson, Stefan
    Morozova-Roche, Ludmilla A.
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Olofsson, Anders
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Gröbner, Gerhard
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Holgersson, Jan
    Esberg, Anders
    Umeå University, Faculty of Medicine, Department of Odontology.
    Strömberg, Nicklas
    Umeå University, Faculty of Medicine, Department of Odontology.
    Landström, Maréne
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Eldridge, Angela M.
    Chromy, Brett A.
    Hansen, Lori M.
    Solnick, Jay V.
    Linden, Sara K.
    Haas, Rainer
    Dubois, Andre
    Merrell, D. Scott
    Schedin, Staffan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Remaut, Han
    Arnqvist, Anna
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Berg, Douglas E.
    Boren, Thomas
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Helicobacter pylori Adapts to Chronic Infection and Gastric Disease via pH-Responsive BabA-Mediated Adherence2017In: Cell Host and Microbe, ISSN 1931-3128, E-ISSN 1934-6069, Vol. 21, no 3, p. 376-389Article in journal (Refereed)
    Abstract [en]

    The BabA adhesin mediates high-affinity binding of Helicobacter pylori to the ABO blood group antigen-glycosylated gastric mucosa. Here we show that BabA is acid responsive-binding is reduced at low pH and restored by acid neutralization. Acid responsiveness differs among strains; often correlates with different intragastric regions and evolves during chronic infection and disease progression; and depends on pH sensor sequences in BabA and on pH reversible formation of high-affinity binding BabA multimers. We propose that BabA's extraordinary reversible acid responsiveness enables tight mucosal bacterial adherence while also allowing an effective escape from epithelial cells and mucus that are shed into the acidic bactericidal lumen and that bio-selection and changes in BabA binding properties through mutation and recombination with babA-related genes are selected by differences among individuals and by changes in gastric acidity over time. These processes generate diverse H. pylori subpopulations, in which BabA's adaptive evolution contributes to H. pylori persistence and overt gastric disease.

  • 309.
    Bugaytsova, Jeanna
    et al.
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Björnhamn, Oscar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Henriksson, Sara
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Johansson, Pär
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Mendez, Melissa
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Sjöström, Rolf
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Brännström, Kristoffer
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Aisenbrey, Christopher
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Shevtsova, Anna
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Bylund, Göran
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Mahdavi, Jafar
    Ögren, Johan
    Ilver, Dag
    Gilman, Robert H
    Chowdhury, Abhijit
    The Swedish Institute for Control, Solna, Swede.
    Mukhopadhyay, Asish K
    Engstrand, Lars
    Oscarson, Stefan
    Kelly, Charles G
    Younson, Justine S
    Odenbreit, Stefan
    Solnick, Jay
    Gröbner, Gerhard
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Haas, Rainer
    Dubois, Andre
    Schedin, Staffan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Berg, Douglas E
    Arnqvist, Anna
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Borén, Thomas
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    pH regulated H. pylori adherence: implications for persistent infection and diseaseManuscript (preprint) (Other academic)
    Abstract [en]

    Helicobacter pylori’s BabA adhesin binds strongly to gastric mucosal ABH/Leb glycans on the stomach epithelium and overlying mucus, materials continuously shed into the acidic gastric lumen. Here we report that this binding is acid labile, acid inactivation is fully reversible; and acid lability profiles vary with BabA sequence and correlate with disease patterns. Isogenic H. pylori strains from the gastric antrum and more acidic corpus were identified that differed in acid lability of receptor binding and in sequence near BabA’s carbohydrate binding domain. We propose that reversible acid inactivation of receptor binding helps H. pylori avoid clearance by mucosal shedding, and that strain differences in acid lability affect tissue tropism and the spectrum of associated gastric diseases.

  • 310.
    Bugaytsova, Jeanna
    et al.
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Chernov, Yevgen A
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Gideonsson, Pär
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Mendez, Melissa
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Henriksson, Sara
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Mahdavi, Jafar
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. School of Life Sciences, CBS, University of Nottingham, Nottingham, UK..
    Quintana-Hayashi, Macarena
    Department of Biochemistry and Cell biology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden..
    Shevtsova, Anna
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Sjöström, Rolf
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Moskalenko, Roman
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Department of Pathology, Medical Institute, State University, Sumy, Ukraine.
    Aisenbrey, Christopher
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Université de Strasbourg, Institut de Chimie, Strasbourg, France.
    Moonens, Kristof
    Structural and Molecular Microbiology, VIB Department of Structural Biology, Belgium.
    Björnham, Oscar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. FOI Totalförsvarets Forskningsinstitut, Umeå, Sweden..
    Brännström, Kristoffer
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Bylund, Göran
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Königer, Verena
    Max von Pettenkofer Institute of Hygiene and Medical Microbiology, LMU, Munich, Germany.
    Vikström, Susanne
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Schmidt, Alexej
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Rakhimova, Lena
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Hofer, Anders
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Ögren, Johan
    Umeå University, Faculty of Medicine, Department of Odontology.
    Ilver, Dag
    Department of Biochemistry and Cell biology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Liu, Hui
    Department of Medicine, USUHS, Bethesda, MD, USA.
    Goldman, Matthew
    Department of Pediatrics, USUHS, Bethesda, MD, USA.
    Whitmire, Jeannette M
    Department of Microbiology and Immunology, USUHS, Bethesda, MD USA.
    Kelly, Charles G
    King's College London, Dental Institute, London, UK.
    Gilman, Robert H
    Department of International Health, John Hopkins School of Public Health, Baltimore, MD, USA.
    Chowdhury, Abhijit
    Centre for Liver Research, School of Digestive and Liver Diseases, Institute of Post Graduate Medical Education & Research, Kolkata, India.
    Mukhopadhyay, Asish K
    Division of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India.
    Nair, Balakrish G
    Translational Health Science and Technology Institute, Haryana, India.
    Papadakos, Konstantinos S
    Hellenic Pasteur Institute, Athens, Greece.
    Martinez-Gonzalez, Beatriz
    Hellenic Pasteur Institute, Athens, Greece.
    Sgouras, Dionyssios N
    Hellenic Pasteur Institute, Athens, Greece.
    Engstrand, Lars
    Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
    Unemo, Magnus
    Department of Laboratory Medicine, Microbiology, Örebro University Hospital, Örebro, Sweden.
    Danielsson, Dan
    Department of Laboratory Medicine, Microbiology, Örebro University Hospital, Örebro, Sweden.
    Sebastian, Suerbaum
    Institute for Medical Microbiology and Hospital Epidemiology Hannover Medical School, Hannover, Germany.
    Oscarson, Stefan
    Centre for Synthesis and Chemical Biology, School of Chemistry, University College Dublin, Dublin, Ireland.
    Morozova-Roche, Ludmilla
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Gröbner, Gerhard
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Holgersson, Jan
    Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden.
    Strömberg, Nicklas
    Umeå University, Faculty of Medicine, Department of Odontology.
    Esberg, Anders
    Umeå University, Faculty of Medicine, Department of Odontology.
    Eldridge, Angela
    Department of Pathology and Laboratory Medicine, University of California Davis School of Medicine, Sacramento, CA, USA.
    Chromy, Brett A
    Department of Pathology and Laboratory Medicine, University of California Davis School of Medicine, Sacramento, CA, USA.
    Hansen, Lori
    Departments of Medical Microbiology and Immunology, Center for Comparative Medicine, University of California Davis, Davis, CA, USA.
    Solnick, Jay
    Departments of Medical Microbiology and Immunology, Center for Comparative Medicine, University of California Davis, Davis, CA, USA.
    Haas, Rainer
    Max von Pettenkofer Institute of Hygiene and Medical Microbiology, LMU Munich, Munich, Germany.
    Schedin, Staffan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Lindén, Sara K
    Department of Biochemistry and Cell biology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Dubois, Andre
    Department of Medicine, USUHS, Bethesda, MD, USA.
    Merrell, D. Scott
    Department of Microbiology and Immunology, USUHS, Bethesda, MD, USA.
    Remaut, Han
    Structural and Molecular Microbiology, VIB Department of Structural Biology, VIB, Brussels, Belgium.
    Arnqvist, Anna
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Berg, Douglas E
    Department of Medicine, University of California San Diego, La Jolla, CA, USA.
    Borén, Thomas
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Acid Responsive Helicobacter pylori Adherence: Implications for Chronic Infection and DiseaseManuscript (preprint) (Other academic)
  • 311.
    Burck, Robin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    ENERGIEFFEKTIVISERING AV VENTILATIONSYSTEM I AITIK, BOLIDEN2015Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    The mine of Aitik is the largest open cast mine in Sweden that refines chalcopyrite. The chalcopyrite is being transported from the open cast mine beneath through a system of underground tunnels to a refinery above ground. There is a ventilation system in the tunnels that is controlled without knowledge of the requirement of ventilation’s force. Boliden has the intention of doing energy saving’s within the corporation. One alternative to save energy is to steer the ventilation. There’s an application called “Ventilation on demand” that steers the airflow of ventilation systems, which can be implemented in the current steering system 800xA. The concept of the application is to minimize the use of energy and both the application and steering system is a product of ABB. Before the implementation of the application a pilot study is needed to chart the airflow based on the requirement to sustain good working environment in the tunnels. The pilot study will contain a situation analysis and a series of measurements with different ventilation speeds. The result of measurement will tell how the ventilation speed affects the air quality in the tunnels and energy use of fans and district heating. The pilot study will also contain the result of cost- and energy savings by installing the application. ‘  The ventilation system contains five fans and two of them have frequency inverters. The air that is forced down to the system of tunnels is heated by district heating trough heating batteries. Skellefteå Kraft is the supplier of the district heating and the pellet boiler is located within the mining area. The situation analysis will be a reference to compare the series of measurements and present the possibilities of cost- and energy savings regarding the working environment in the tunnels.  The result demonstrates the possibilities of making energy savings up to sixty percent and still have a good working environment. The result also demonstrate that “Ventilation on demand” has a short payback time.

  • 312.
    Burlin, Jesper
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Geoenergi med och utan värmepump2017Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete utfördes på uppdrag av Umeå Kommun. Uppgiften bestod av att utvärdera dagens användning av en borrhålsbrunn samt undersöka vad som är det optimala användningsområdet för borrhålsbrunnen. Borrhålsbrunnen används i dagsläget för att förvärma samt kyla utomhusluft in till kontorsbyggnaden Kubens ventilationsaggregat.

    Ventilationens förvärmning består av två delar, en markkanal och ett geoenergibatteri. Viktiga parametrar hos förvärmningen analyserades med hjälp av mätvärden för temperatur och flöde. Resultaten jämfördes därefter med alternativet att använda borrhålsbrunnen tillsammans med en värmepump. Då borrhålsbrunnens kapacitet inte var tillräcklig för att klara byggnadens hela uppvärmningsbehov, undersöktes det hur en värmepump skulle kunna köras i kombination med fjärrvärme. Två driftstrategier, Bas och Kapatoppar, undersöktes. Bas leverar en basproduktion under hela vinterperioden medan Kapatoppar startar vid -6°C för att sänka effekttoppar.

    Utvärderingen av förvärmningen visade att geoenergibatteriet är mer kompatibelt med ventilationsaggregat av VAV-typ (Variable Air Volume) än vad markkanalen är. Däremot är inte förvärmning i kombination med roterande värmeväxlare ett bra koncept för byggnaden som den används idag. På grund av att förvärmningen är placerad före den roterande värmeväxlaren så är bara 15-20 % av förvärmningseffekterna energibesparande. Detta kombinerat med en optimerad drift av aggregatet sett till tidsstyrning och behovsstyrning av flöde gör att förvärmningen har en liten påverkan både på byggnadens maximala effektbehov och totala energibehov.

    Att köra värmepump i kombination med fjärrvärme för uppvärmning var ekonomiskt lönsamt främst på grund av att värmepumpen kunde kapa byggnadens effektoppar. Kostnaden för storleken på den abonnerade effekten uppgår idag till drygt 40 % av den totala fjärrvärmekostnaden. Dagens relation mellan el- och fjärrvärmepriser bidrog naturligtvis också till att värmepumpsalternativet var lönsamt. För de undersökta förutsättningarna så blev paybacktiden för en värmepump med den lönsammaste driftstrategin, Bas, 4,4 år.

  • 313.
    Burman, Sebastian
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energiuppföljning på två flerbostadshus i centrala Skellefteå.2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    One third of Sweden's energy use is used by residential and commercial buildings, of which nearly 60 % go to heating. Opportunities are great for using energy more efficiently and there is a great potential to save energy by improving the construction of the building. The EU places higher demands on energy use and means that monitoring of energy use is becoming increasingly important. From 2021, all new production of buildings in EU Member States will be "close to zero energy houses". The definition of "near zero energy house" has not yet been established in Sweden, but in a throw-out of BBR is the requirement to tighten by 40 % discussed. Efforts to get more energy-efficient buildings are under way and are being carried out in close collaboration with BBR.

     

    This degree project has been carried out on behalf of Skebo, where the goal is to establish the real specific energy use in operation for two properties in Skellefteå, Ringduvan and Odenskrapan. Compare and analyze deviations from projected specific energy use. Ringduvan was ready for occupation in spring 2014 and Odenskrapan in early 2016.Both buildings have electricity and district heating from Skellefteå Kraft. Ringduvan is projected by NCC and Oden of Lindbergs Energi & VVS AB.

     

    Sveby ("Standardize and Verify Energy Performance in Buildings") is a development program run by actors in the construction and real estate industry. Svebys aim is to develop an industry standard that increases the accuracy of the project between projected and real energy use. With increased knowledge of user-related use, a standardized approach, energy monitoring and enhanced cooperation between actors, the goal is to reduce the deviations. Operators in the industry may choose to enter into a Sveby agreement, which includes a common method of procurement, design and verification.

     

    The projected specific energy use for Ringduvan is 76 kWh/m2,year and the real is 101 kWh/m2,year. Odenskrapan projected is 53 kWh/m2,year and the real is 93 kWh/ m2,year. That is, the specific energy use exceeds the estimated energy consumption by 33 % for Ringduvan and 75 % for Odenskrapan. This means that much more district heating and real estate is needed than expected.

     

    In general, potential causes of higher energy use have been identified. But nothing has been confirmed and more work is required against the buildings in order to compare and identify the exact reasons.

  • 314.
    Burman, Simon
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energianalys av MVG-gallerian, samt en jämförelse av beräkningsprogram2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis has been carried out in the spring of 2013, on behalf of Sweco Systems in Umeå. The aim of this work was to evaluate the possibilities of using any energy simulation software in the work of mapping energy usage of existing facilities. In this study two of the softwares that is being used in the company are evaluated – VIP-Energy and IDA Indoor Climate and Energy.

    Initially a mapping of the energy usage was performed on the property Odin 12 in Umeå, which consists mainly of the mall MVG. The energy usage was then simulated with the two different softwares.

    The mapping of energy usage shows that the building has a low annually need of space heating. This is due to the fact that the consumption of electricity in the building is very high, which leads to very high internal loads and a low need for additional heating. For the same reason, a need of space cooling is present during the whole year.

    The evaluation of the two energy simulation softwares shows that VIP-Energy is a suitable program for energy mapping. The program is both simple and flexible which reduces the time needed for creating the model.  Considering the time for the actual calculations, VIP-Energy is the program that is by far the fastest.

  • 315.
    Bygdén, Olov
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Testpiloter i praktisk energieffektivisering: Visualisering och kommunikation2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta arbete har utförts på Skellefteå Kommuns fastighetsavdelning under hösten 2012 och även under början på 2013. Fastighetsavdelningen är ansvariga för bl.a. driften hos Skellefteå Kommuns byggnader och därmed också ansvariga för att minska energianvändningen hos dessa. Till år 2016 har Skellefteå Kommun som mål att åstadkomma en energieffektivisering på 20 % jämfört med utgångsåret 2009. Detta projekt har utförts som en del av detta energieffektiviseringsarbete.

     Projektet omfattar två olika mätperioder, under den andra av dessa mätperioder installerades visualiseringsskärmar hos de två berörda objekt som utvalts till detta projekt. På visualiseringsskärmarna visades sedan den momentana energiförbrukningen för att brukarna skulle kunna hålla koll på om förbrukningen ökade eller minskade sett till den senaste veckan. Två informationsträffar, en för varje arbetsplats, hölls också för att informera om projektet samt att ge tips på tänkbara förändringar i arbetsmetoderna som skulle kunna medföra minskad energiförbrukning och därigenom ett positiv resultat.

    Resultatet av detta projekt blev en mängd mätdata som har sammanställts och analyserats för att slutligen resultera i ett utfall i form av att det ena objektet minskade sin energiförbrukning med 1,7 % och det andra objektet med hela 24,2 %.

    Slutsatsen har därmed blivit att visualisering samt kommunikation kan vara ett tänkbart alternativ till att åstadkomma en minskad energianvändning och motivera brukare av lokaler att bli engagerade och bidra själva.

  • 316.
    Bylin, Daniel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Konstruktion av dörrstopp2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree project has been carried out within the bachelor program inmechanical engineering at Umeå University In collaboration with Volvo TrucksABin Umeå. The purpose of thiswork is to construct a door stop that makes it possibleto open and close the door of the cab during the manufacturing process ofcolor treatment.

    With today's solution, the company encounters problems with color splashing from the door stop, which generates defects on the paintsurface. It can also happen that the door opensduring the manufacturing process, as today's construction contains a spring that becomes worn.

    The initial part of the project involved gathering knowledge about the actual problem and how the manufacturing process works. Contact with experts on site and visits during production a requirement specification on the fixture could be established.

    A concept generation phase was performed where several concepts emerged. An order to find out which of these concepts had the best conditions to make an improvement to today's solution, they were placed in an elimination matrix and examined with the help of supervisors. A physical prototype was created by the concept chosen to proceed with.

    The construction work has primarily been carried out in the CAD-program Catia, which is a standard within Volvo.

    At the end of the report improvements are discussed if further work is to be carried outwith this project.

  • 317.
    Bylund, Kristoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Elnätsautomation i distibutionsnätet: Feldetektering och fjärrstyrning som metoder att förbättre leveranssäkerheten i elnätet2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Att öka leveranskvaliteten i sina elnät är något som varje nätbolag strävar mot. En metod att göra detta kan vara att utrusta nätstationer i mellanspänningsnätet med feldetektering och fjärrstyrning för snabbare felsökning och sektionering vid fel. I denna studie har dessa möjligheter utretts och även de potentiella vinsterna i kortare avbrottstider mätt i indikatorn SAIDI. Studien har resulterat i ett förslag för fortsatt investering i feldetektering och fjärrstyrning i Umeå Energis elnät. Den metod som använts är att beräkna SAIDI för det värsta felscenariot för varje matande linje som tittats på, både med och utan elnätsautomation. Det förslag som tagits fram har utgått ifrån de enskilda matningarna förutsättningar vad gäller kundantal, antal nätstationer och nättopologi och har sedan jämförts med två standardalternativ, med detektering i samtliga nätstationer samt detektering i mitten av linjen. Resultatet visar att det förslag som lämnats till Umeå Energi har potential att sänka det summerade SAIDI-värdet vid värsta felscenario från 37 minuter till 10 minuter i de matningar som undersökts. Detta till en kostnad av mindre än två miljoner kronor, eller en kostnad per potentiellt minskad SAIDI-minut på ca. 70 000 kr. Studien har tittat på 16 matande linjer med totalt ca. 17 000 kunder. 

  • 318.
    Byström, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    En extra fasadskivas effekt på energiprestandan hos ett flerbostadshus: En kontroll av Boverkets krav för nära-nollenergibyggnader till 20212017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Increasing the energy efficiency of buildings and the introduction of more strict regulations are small but important steps towards a better climate. Today the housing and services sector stands for nearly 40 % of Sweden’s energy use. To push the development towards more energy efficient buildings in Europe, all the new buildings are required to be nearly zero-energy buildings by 2021.

    The purpose of this project was to evaluate whether the use of an additional facade board on an apartment building results in putting the energy performance within the current energy performance requirements, and also within the future requirements for nearly zero-energy buildings (NZEBs). The facade boards that were tested in this project are manufactured by Kingspan and Isover. The different boards were tested in thicknesses of 30 and 50 mm. The aim of the project was to calculate the building’s average heat transfer coefficient, specific energy use and primary energy number (PET) using COMSOL Multiphysics (CM) and IDA Indoor Climate and Energy (IDA ICE). The results were then about to be controlled against the current energy performance requirements together with the future requirements for NZEBs.

    The approach of this project consisted of the use of the softwares CM and IDA ICE. Because IDA ICE requires input of the thermal bridges of the building, CM was used to simulate these. This was done in order to achieve more reliable values than if an assumption was made or a standard value was used. A model of the building was then created in IDA ICE where its energy performance and average heat transfer coefficient were obtained from simulations over a normal year.

    The results obtained from the simulations in CM seemed credible as the use of the best facade board caused the values of the thermal bridges to end up at ”Good” according to IDA ICE’s built in scale. The simulations in IDA ICE showed that the specific energy use of the bulding without an additional facade board was 55,9 kWh/m2,year compared to Boverket’s current requirements at 80 kWh/m2,year. With the 50 mm Kingspan facade board, the board with the best result, the specific energy use was reduced to 53 kWh/m2,year, an improvement of 5,2 %. For the case without an additional facade board, the PET was 66,6 kWh/m2,year compared to the NZEBs requirements for 2018 at 85 kWh/m2,year together with the requirements for year 2021 at 65 kWh/m2,year. By using the 50 mm Kingspan facade board the PET was reduced to 63,3 kWh/m2,year, an improvement of 5,0 %. This resulted in putting the PET below the NZEB requirements for 2021. The facade board that resulted in the least energy savings, Isover P31 30 mm, had an improvement of 2,5 and 2,7 % for the specific energy use and the PET respectively. This facade board also resulted in putting the PET below the NZEB requirements for 2021.

    The most obvious conclusions that could be drawn from the simulations was that the specific energy use was below the current energy performance requirements with a great margin, both with and without an additional facadeboard. The PET was well below theNZEB requirements for 2018 and was also belowthe NZEB requirements for 2021 using any of the tested facade boards. The building’s average heat transfer coefficient was also well below both today’s energy performance requirements and the NZEB requirements for 2018 and 2021. A use of an additional facade board resulted in an energy saving of around 2,5 and 5 % in the worst and the best case, respectively. Due to the neglect of the ring wall under the bulding, the energy performance is most probably slightly high. However, this is not of utmost relevance since the company normally does not use this kind of solution for their standard buildings. Other uncertainties about the choice of airflows in property spaces may have influenced the results in the other direction. If there are any other obvious energy saving measures than using an additional facade board, these should be taken into account primarily as a facade board can only reduce the energy use marginally.

  • 319.
    Byström, Jonas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Verifiering av en kontorsbyggnads energianvändning2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis was commissioned by the department Fastighet (Real estate) at Umeå municipality in the spring of 2016. Since Fastighet represents Umeå municipality as landlords they are obliged by the Swedish law (2006:985) energy certification of buildings to declare a building’s energy use within two years after the building started operating.

    In this thesis an investigation was made regarding the energy use of an office building named Kuben, located at the city hall area in Umeå, Sweden. The purpose of the project was to investigate whether the building met the demands regarding its energy use. In addition an analysis was made during the project to indicate the reasons for the discrepancies between the energy consumption for the simulation model in IDA ICE and the measured energy consumption of Kuben in the year of 2015.

    According to the energy balance calculation in IDA ICE, it was found that the building was expected to have a specific energy use (BSE) of 52 kWh/m2,year, while in reality the building had a measured BSE of 91,1 kWh/m2,year in the year of 2015. Therefore Kuben did not fulfill the main requirement of the Green Building which is 90 kWh/m2,year, but it did however fulfill the BBR requirement.

    The reason behind the large deviation in BSE is primarily due to the occupants having used significantly less electricity than expected, combined with a higher use of domestic hot water and higher indoor temperatures than expected. Another detection factor that has further increased the differences is the fact that the ventilation system has been switched on basically around the clock during the year of 2015. Something which is very common during the building’s first year of operation since the building is setting and the construction body is in a dry-phase and emissions are being vented.

    To be able to perform a follow-up on a building’s energy consumption, it is very important to have access to real data of the energy sources included in BSE, in order to really be able to verify whether the building meets the requirement or not. It is also an advantage if there is a possibility to have access to lots of sub-meters, since it makes it easier to determine and verify the causes that lead to deviation between the energy use for the simulation model and measured data.

    It is recommended that a follow-up regarding the buildings energy use should take place during the building’s second year of operation or later, since the first year contains more reasons that can cause deviation and that the BSE is higher than normal because of the complications.

  • 320.
    Byström, Stig
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Berglund, Stefan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Kvalitetshöjning med avseende på projektledningsinnehållet i ingenjörs- och civilingenjörsutbildningar2013In: Utvecklingskonferensen för Sveriges ingenjörsutbildningar, 2013, p. 85-88Conference paper (Other academic)
    Abstract [sv]

    Hösten 2010 startade projektet ”Fortbildning av lärare i projektledning” med syftet att ytterligare förbättra kvalitén på ingenjörsutbildningar genom ett tydligare projektledningsinnehåll. Projektet bedrivs vid Institutionen för tillämpad fysik och elektronik (TFE) och strategiska utvecklingsmedel erhålls frånTeknisk-naturvetenskaplig fakultet, Umeå universitet. Vi har utvecklat ett kostnadseffektivt och självbärande koncept där nästan halva kompetensutvecklingstiden betalas genom att deltagaren utför handledning och återkoppling till studenter i en projektledningskurs. Övrig kompetensutvecklingstid i konceptet finansieras av deltagares egna enheter. Projektet pågår fram till juni 2014, hittills har 15 deltagare fortbildats.

  • 321.
    Bäck, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Back-end development of mobile application for the collection of dietary data2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Smartphones are used by incredibly many people, and in 2011 there where a total of 491.4 million units soled worldwide. This makes it a relevant technique for performing dietary studies when the test patients are on the move. This thesis shows how to create a back end environment for an Android application with existing techniques linked together, using MSSQL database, Visual Studio Web Service, web pages and C# classes and ASP.NET security. The back end development is used in a dietary study on Gothenburg University, butcould be applied on many similar back end projects using databases and server development.Techniques used in this thesis are: REST (Representational State Transfer) -client implementation and development inside the Android application, using HTTP methods to set and get information from the server and database, and JSON-format to read and transferinformation in an easy and understandable way, both from the Android application and from the database. FileMaker is also used in this project as a third part programme tovisualise the information in the database.

  • 322.
    Bäck, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Back-end development of mobile application for the collection of dietary data2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Smartphones are used by incredibly many people, and in 2011 there where a total of 491.4million units soled worldwide. Smartphones are known as advanced phones, or personal digital assistants (PDAs). This makes a relevant technique for performing dietary studies when the test patients are on the move. This thesis shows how to create a back end environment for an Android application with existing techniques linked together, using MSSQL database, Visual Studio Web Service, web pages and C# classes and ASP.NET security.The back end development is used in a dietary study on Gothenburg University, but could be applied on many similar back end projects using databases and server development.Techniques used in this thesis are: REST (Representational State Transfer) -clientimplementation and development inside the Android application, using HTTP methods toset and get information from the server and database, and JSON-format to read and transfer information in an easy and understandable way, both from the Android application and from the database. FileMaker is also used in this project as a third part programme to visualise the information in the database.

  • 323.
    Bäcklund, Johannes
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektivisering av fjärrvärme- och fjärrkylanätet på campus i Umeå: Energy efficiency of the district heating and cooling systems on campus in Umeå2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete utfördes på uppdrag av Akademiska Hus som äger och förvaltar fastigheterna på campus i Umeå. Projektet bestod av att utifrån en övergripande bild på det interna fjärrvärme- och fjärrkylanätet på campus, ta fram alternativa utformningar på systemet i syfte om att göra det mer energieffektivt.

    Systemets interna fjärrvärme- och fjärrkylanät VP100 och KB100 växlar över värme och kyla från Umeå Energi som sedan distribueras vidare till fjärrvärme- och fjärrkylacentraler på campus. Några av centralerna har egenproduktion där returledningen från KB100 går till en värmepump som producerar både värme och kyla. Producerad värme används till att förvärma returledningen från uppvärmningssystemen från de byggnader som hör till respektive central. När behovet av värme är tillräckligt stort är systemet, tack vare värmepumparna, självförsörjande gällande kyla. Produktion sker alltså endast under de perioder då det finns behov i uppvärmningssystemen. Det leder till att systemet tvingas köpa både värme och kyla samtidigt under sommaren då behovet av kyla i stort sett är konstant under året.

    Två alternativa utformningar till det befintliga systemet har undersökts. Det första fallet har som syfte att reducera värmeförlusterna i VP100. Det andra fallet byggdes vidare på det första fallet med syftet att utvidga arbetsområdet för värme- och kylproduktionen i värmepumparna.

    Resultatet visar att det finns potential att mer än halvera värmeförlusterna i det befintliga VP100 och att produktionen av värme och kyla skulle kunna öka med 10 % respektive 6 %. Totalt skulle systemet kunna spara drygt 1,3 miljoner kWh per år genom en kombination av de två alternativa utformningarna. För att däremot få energibalans i systemet där det aldrig behöver köpas både värme och kyla samtidigt bör andra effektiviseringsåtgärder övervägas. 

  • 324.
    Bäcklund, Tomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Development and validation of a system for clinical assessment of gait cycle parameter in patients with idiopathic normal pressure hydocephalus2013Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A number of parameters have been identified as characteristic of the walking pattern in patients with INPH. Most of these have been identified through qualitative surveys and manually conducted test batteries. In order to obtain quantitative, standardized and objective measures, which enable studies based on larger patient populations and comparable results, there is a need for a user-friendly system that can measure specific key parameters over time in a reliable manner in everyday clinical work. Step height, width and the variability in the gait cycle are such parameters which are interesting research areas for this group of patient.

    Problems with balance and gait are very common in other patient groups as well, particularly in neurological diseases such as Parkinson's disease, multiple sclerosis and stroke.

    This is the reason that the development of this gait analyzer is performed. Giving access to a simple and objective method for estimating gait and balance ability in clinical routine investigations would increase the ability to provide the right kind of treatment, confirm treatment results, and conducting larger research studies. Therefore, this equipment can contribute to the assessment of diseases which contain impaired gait. As a first test of the usability and for the validation of accuracy and repeatability of the equipment a group of healthy volunteers was used. Results from tests on healthy subjects show god repeatability between measurements, for step width at normal gait the difference was -0,2 ±0,34 cm (mean, ±SD) and step height 0,69 ±3,34 cm. The stride time variability in the healthy group where very small 0,00048 ±0,00028 s2 with a difference between test of 0,000019 ±0,00038 s2. Three pilot patients have been tested where we have clearly seen indications of increased stride time variability and reduced step height.

  • 325.
    Bäcklund, Tomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Konstruktion av tryckförstärkare2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 326.
    Bäckström, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Optimerad värmeleverans från Hedensbyverket2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Skellefteå Kraft AB has currently problems with the central district heating network in Skellefteå concerning low pressure difference between the delivering, hot, and returning, cold, pipeline. Cause of this low so called differential pressure, the customers heating requirements in these areas is not fulfilled in a satisfying way. The intent of this project has been, with the use of simulations, to clarify if a solution can be possible by connecting an increasing pressure pump to the district heating network. A pumpstation will be placed in such a way that it improves the ability to control the pressurization of the district heating pipelines and also makes it possible to distribute more heat from Hedensbyn, where the main production of district heat in Skellefteå takes place. Determine if the increase in pressure may result in an increase in electricity production, by lowering the temperature of the outgoing water.

    The result is this project shows that placing a pumpstation at Moröskolan is the most advantageous position. An increasing pressure pump at Moröskolan in Skellefteå would create more favourable conditions in order to control the pressure in the district heating network and maintain a minimum differential pressure. The simulations made shows that with a pumpstation, it is possible to distribute up to 20 MW more heat from the Hedensbyn. A pressure increase in the district heating network would currently allow for an increase in electricity distribution of approximately 4-5,5 GWh/year. Based on these results, the project concerning the pump is planned to begin during spring 2011.

  • 327.
    Bäckström, John
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Intellus360 Push -Mobilitet där det behövs2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Intellus AB has a large need to inform users when their monitoring software finds erroneous behavior in the monitored processes. To provide such service to the users, an application for mobile devices has been developed during the course of this project. High demands have been that the application must be available on both iOS-devices and Android operated devices. The primary priority in the actual implementation has been to notify the devices as fast as possible when an alert has occurred. Other high priorities has been to make the user experience as pleasant as possible with easy navigated applications and stability, the applications are not allowed to crash when used by a user. During development concepts like APNs- and C2DM-messages, XML document and HTTP requests has been evaluated.The result from the project involves two applications, one for iOS devices and one for Android devices, and a server environment to handle messages. The both applications have the same functionality where a message is pushed with Apples APN-framework and Google’s C2DM-framework to the devices. When the user sees the message and chooses to investigate more, all the data about the message is downloaded with an HTTP request as an XML document.In the end of the report future work is discussed and an example from the discussion is that it would be good to implement a search functionality to let the user search for specific messages on the server.

  • 328.
    Bäckström, Lars
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Guilloux, Tom
    Fusing Kite and Tether into one Unit2017In: Airborne Wind Energy Conference 2017: Book of Abstracts / [ed] Moritz Diehl, Rachel Leuthold, Roland Schmehl, Freiburg, Germany: Albert-Ludwigs-Universität Freiburg; Delft University of Technology , 2017, p. 40-41Conference paper (Refereed)
  • 329.
    Bäckström, Marcus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Pneumatisk Dragprovmaskin: För uppmätning av separationskrafter för skogsplantor från deras kassetter i samband med plantering vid olika förhållanden.2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Bracke Forest AB tillverkar maskinella planteringsaggregat som utvecklas för en modernare och en mer noggrann skogsplantering. Deras planteringsaggregat har ett begränsat antal platser i hållaren som lagrar plantorna innan de sätts i marken. Aggregatet laddas med nya plantor manuellt av skogsmaskinens operatör, där en planta flyttas från dess kassett till hållaren. En process som Bracke Forest AB planerar att förändra på nästa generations planteringsmaskiner.

    Syftet med detta examensarbete är att ta reda på vilka krafter som uppstår vid lyft av planta från dess kassett, vilket ska ligga som underlag vid utvecklingen. I detta examensarbete testas olika kassetter där snabba och långsamma hastigheter jämförs vid blöta och återbevattnade förhållanden, för att ta reda på vilken kassett som lämpar sig bäst för automatisk hantering. Examensarbetet begränsas till gran och tall där de tre kassetterna Hiko, Jackpot och Starpot från respektive skogsbolag analyseras.

    En egenkonstruerad pneumatisk dragprovmaskin tillverkas och med hjälp av en analog tryckgivare registreras tryckskillnaden via ett styrkort, Arduino Mega 2560. Tryckskillnaden beräknas om till kraft och ett resultat i form av tabeller och diagram tas fram. För att kontrollera att den egenkonstruerade dragprovmaskinen redovisar relevanta resultat används en befintlig dragprovmaskin som referens. Detta examensarbete berör pneumatik, 3D-konstruktion i Solidworks, elektronik, Arduino programmering, tillverkning och grafisk analys av analog signaldata.

    Resultatet från dragproven visar att Starpot kassetten kräver minst medelkraft för lyft av en planta från dess kassett. På grund av att rötterna för både Starpot och Jackpot kunde fastna i kassetten och gå av vid dragningarna är rekommendationen att använda Hiko-kassetten, då dess plantor kan dras vid olika hastigheter utan att rotdelning uppstod.

  • 330.
    Bäckström, Simon
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Dagsljusinsläpp genom fasad: Undersökning av fönsterlösning med reflekterande ljushylla2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Buildings are constantly developing and becoming more energy efficient. This progress is partly down to building regulations forcing constructions to be better insulated, but also by using more energy efficient materials. In modern energy efficient buildings the windows are a great cause for concern. They contributes to heat loss, and if not shaded in a good way they can increase the needs for additional cooling during summer. Well planned property fenestrations can decrease the window area and thereby minimizing energy loss through windows.

     

    In the project Kub och Länk in Umeå, Link arkitekture has created a fenestration solution with a light shelf. The purpose of the light shelf is to help increase daylight transport further in to the building. This report investigates the window positioning and analyses the benefits of the light shelf.

     

    Velux daylight visualizer is used to analyze the building through computer analysis. Simulations were made in both clear and overcast skies analyzing, luminance, illuminance and daylight factor.

     

    The analyses of the daylight factor showed that the original solution was good enough to reach the gold level of Miljöbyggnad. Further simulations of the different fenestrations showed that this was not likely a result of the light shelf itself. In fact, most result indicated that the light shelf was shading the room more than lighting it and therefore created less use of the window area than regular window solutions.

  • 331.
    Bäckström, Tove
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Large digital screen as a corporate communication channel: Enhancing the dissemination of information, administration and interaction2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Public areas are more and more equipped with digital screens that are used to inform or promote a particular product. This is a way to communicate with the people on that area. The idea is to get people's attention, make them read and take in information and possibly buy the product that is marketed. This type of digital display is called digital signage and can also be used as an information channel of a company where information directed to employees and visitors is displayed. CGI Östersund has a screen placed in their office that works as such an information channel.

    This thesis is about investigating and analyzing the current presentation and creating a new solution with a custom interface that will be more effective and engage more people.

    The new solution is interactive and clickable with the help of a mouse. A user study has been done using a Kinect sensor to see how many people are watching the screen, how long they look at the screen and from what distance. This data was also supplemented by a survey sent to the employees at CGI Östersund. The result of the user study shows that there was no significant difference between the previous solution and the new one. This may be due to two main reasons: the lack of time in which the experiment was performed and the location of the digital screen that is not currently optimal.

  • 332.
    Bäfver, Linda
    et al.
    Pöyry SwedPower.
    Renström, Caroline
    Pöyry SwedPower.
    Fahlström, Johan
    Ragn-Sells.
    Enfält, Patrik
    EasyMining Sweden.
    Skoglund, Nils
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Holmén, Erik
    ENA Energi.
    Slambränsleblandningar: Förbränning och fosforutvinning2013Report (Other academic)
    Abstract [en]

    For sustainable phosphorus recycling, the phosphorus in sewage sludge needs to be recovered, as it is a major phosphorus-source. However, all sludge is not suitable for direct recycling on agricultural land, e.g. when the content of heavy metals is too high. To achieve an increased recycling of phosphorus from sewage sludge there is a need of research and development of alternative methods to return the phosphorus from sewage sludge to agricultural land.

    The aim of the project is to show that sewage sludge can be co-combusted with demolition wood in existing boilers, and that the ash can be processed for extraction of phosphorus, together with valuable by-products from the process. Further effects of the project will be the development of new knowledge about combustion with a high sludge to demolition wood ratio in a grate boiler (up to 45 % sludge with respect to wet mixture), which has not been studied in full-scale combustion earlier. The project's goal is to demonstrate mixing and combustion of fuel mixtures of sludge and demolition wood, and subsequent extraction of phosphorus from ash. The target groups for this work are energy companies, suppliers of grate boilers, municipalities, wastewater treatment plants and authorities.

    The project involves the mixing of sewage sludge and demolition wood, combustion-tests of the fuel mixtures and laboratory experiments on bottom ash and fly ash for phosphorus extraction using EasyMining Sweden's method for phosphorus extraction from ash. Extensive analyses have been carried out on fuel, bottom ash and fly ash, as well as thermodynamic equilibrium calculations on the formed compounds containing phosphorus.

    The experience of preparing sludge fuel mixtures shows that the mixtures should be prepared in the near future to when they are to be combusted, to avoid a composting process in the fuel. The project shows that it is possible to combust sludge fuel mixtures with an admixture of up to 45 % sludge relative wet fuel, in an existing grate boiler during one day. However, to combust sludge fuel mixtures over a longer period of time and at a higher load, modifications of the de-ashing system and the flue gas cleaning system are needed. The results indicate a reduced tendency of slagging on the fuel bed at the combustion of sludge mixtures. The analyses of the fly ash showed a trend towards less corrosive ash at combustion of sludge mixtures. The phosphorus content in the ash in this work was 3-4 %. For process economics and from the phosphorus extraction point, as high phosphorus content as possible in the ash is preferable. Higher phosphorus content can be accomplished by mixing sludge with a fuel with lower ash content than demolition wood, co-combustion with a fuel with higher phosphorus content than demolition wood, or by increasing the percentage of sewage sludge in the fuel mixture. Still, a higher proportion of sludge in the mixture would require a higher dry matter content of the sludge in order to get proper combustion conditions. It is primarily bottom ash that is suitable for phosphorus extraction using Easy Mining Sweden's method. If fly ash are to be used for phosphorus extraction, an optimization of the dissolution conditions is required, which was not included in this project. In this project, phosphorus is extracted as ammonium phosphate. The purity of ammonium phosphate is very high, which means that unwanted substances and heavy metals in sewage sludge will not be returned to contaminate fields.

  • 333.
    Bååth, Johanna
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Evaluating University course search: - development of a new user-centred interface concept2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Findwise is a Europe-wide producer of search solutions. One of their search solutions included a university course search interface, which needed revision due to a loss of coherence in the structure. This had negative impact on the simplicity and usability. The thesis describes a process for improving the interface design and user-friendliness of the course search. The search interface previously developed by Findwise have been studied and evaluated in order to develop and bring forward a proposal for a new interface design mock-up. In addition to this, two areas have been explored in more detail; search engines and Human computer interaction methods.

    The resulting proposal consist of usable methods for structuring course search interfaces, creating a more intuitive new design.

  • 334.
    Cabral, Regis
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    QoE: Quality of Experience: a conceptual essay2007In: Integration and Innovation Orient to E-Society, Vol 2: Seventh IFIP International Conference on e-Business, e-Services, and e-Society (13E2007), October 10–12, Wuhan, China / [ed] Weijun Wang, Yanhui Li, Zhao Duan et al, New York: Springer-Verlag New York, 2007, Vol. 252, p. 193-199Conference paper (Refereed)
    Abstract [en]

    The ICT industry and services are on the verge of substituting quality of service and utility functions; with quality of experience, QoE. While intuitive, QoE, has eluded the research community. QoE takes into account what the user is experiencing with new products and services. Once this information is collected, it becomes an input in the development of the new product or new service. But how does one measure directly quality of experience? In this conceptual paper, I discuss from an ICT perspective, the utility function and quality of service, QoS. I also present how active interested the industry is in QoE. I concluded with some key points that may serve as a guideline in the process of constructing the QoE function.

  • 335.
    Candefjord, Stefan
    et al.
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Nyberg, Morgan
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Jalkanen, Ville
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Ramser, Kerstin
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Lindahl, Olof
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Combining fibre optic Raman spectroscopy and tactile resonance measurement for tissue characterization2010In: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 21, no 125801, p. 1-8Article in journal (Refereed)
    Abstract [en]

    Tissue characterization is fundamental for identification of pathological conditions. Raman spectroscopy (RS) and tactile resonance measurement (TRM) are two promising techniques that measure biochemical content and stiffness, respectively. They have potential to complement the golden standard-–histological analysis. By combining RS and TRM, complementary information about tissue content can be obtained and specific drawbacks can be avoided. The aim of this study was to develop a multivariate approach to compare RS and TRM information. The approach was evaluated on measurements at the same points on porcine abdominal tissue. The measurement points were divided into five groups by multivariate analysis of the RS data. A regression analysis was performed and receiver operating characteristic (ROC) curves were used to compare the RS and TRM data. TRM identified one group efficiently (area under ROC curve 0.99). The RS data showed that the proportion of saturated fat was high in this group. The regression analysis showed that stiffness was mainly determined by the amount of fat and its composition. We concluded that RS provided additional, important information for tissue identification that was not provided by TRM alone. The results are promising for development of a method combining RS and TRM for intraoperative tissue characterization.

  • 336.
    Candefjord, Stefan
    et al.
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Nyberg, Morgan
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Jalkanen, Ville
    Umeå University, Faculty of Science and Technology, Applied Physics and Electronics. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics.
    Ramser, Kerstin
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Lindahl, Olof
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Evaluating the use of a Raman fiberoptic probe in conjunction with a resonance sensor for measuring porcine tissue in vitro2009In: IFMBE Proceedings of the World Congress on Medical Physics and Biomedical Engineering, Heidelberg: Springer , 2009, p. 414-417Conference paper (Refereed)
    Abstract [en]

    Prostate cancer is the most common form of cancer and is the third leading cause of cancer-related death in European men. There is a need for new methods that can accurately localize and diagnose prostate cancer. In this study a new approach is presented: a combination of resonance sensor technology and Raman spectroscopy. Both methods have shown promising results for prostate cancer detection in vitro. The aim of this study was to evaluate the combined information from measurements with a Raman fiberoptic probe and a resonance sensor system. Pork belly tissue was used as a model system. A three-dimensional translation table was equipped with an in-house developed software, allowing measurements to be performed at the same point using two separate instruments. The Raman data was analyzed using principal component analysis and hierarchical clustering analysis. The spectra were divided into 5 distinct groups. The mean stiffness of each group was calculated from the resonance sensor measurements. One of the groups differed significantly (p < 0.05) from the others. A regression analysis, with the stiffness parameter as response variable and the principal component scores of the Raman data as the predictor variables, explained 67% of the total variability. The use of a smaller resonance sensor tip would probably increase the degree of correlation. In conclusion, Raman spectroscopy provides additional discriminatory power to the resonance sensor.

  • 337.
    Candefjord, Stefan
    et al.
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Nyberg, Morgan
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Jalkanen, Ville
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Ramser, Kerstin
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Lindahl, Olof
    Dept. of Computer Science and Electrical Engineering, Luleå University of Technology.
    Kombinationsinstrument för detektering av prostatacancer: korrelation mellan resonanssensor och fiberoptisk Ramanprobe2009In: Medicinteknikdagarna 2009, Svensk förening för medicinsk teknik och fysik , 2009, p. 60-Conference paper (Refereed)
  • 338.
    Cao, Guoqing
    et al.
    Tianjin University.
    Tu, Guangbei
    Tianjin University.
    Yang, Bin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Study of optimum horizontal shading device dimensions for energy saving in residential buildings2006In: Taiyangneng Xuebao, Vol. 27, no 1, p. 96-100Article in journal (Refereed)
  • 339. Capablo, Joaquin
    et al.
    Arendt Jensen, Peter
    Hougaard Pedersen, Kim
    Hjuler, Klaus
    Nikolaisen, Lars
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Frandsen, Flemming
    Ash properties of alternative biomass2009In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 23, p. 1965-1976Article in journal (Refereed)
    Abstract [en]

    The ash behavior during suspension firing of 12 alternative solid biofuels, such as pectin waste, mash from a beer brewery, or waste from cigarette production have been studied and compared to wood and straw ash behavior. Laboratory suspension firing tests were performed on an entrained flow reactor and a swirl burner test rig, with special emphasis on the formation of fly ash and ash deposit. Thermodynamic equilibrium calculations were performed to support the interpretation of the experiments. To generalize the results of the combustion tests, the fuels are classified according to fuel ash analysis into three main groups depending upon their ash content of silica, alkali metal, and calcium and magnesium. To further detail the biomass classification, the relative molar ratio of Cl, S, and P to alkali were included. The study has led to knowledge on biomass fuel ash composition influence on ash transformation, ash deposit flux, and deposit chlorine content when biomass fuels are applied for suspension combustion.

  • 340.
    Carlborg, Markus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Exposure studies of refractory materials for biomass gasification2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Gasification is a technology mostly used to convert fossil feedstock to syngas. Biomass could be used as a feedstock instead but that puts different demands on, among other things, the materials in these reactors.

    In this work, two candidate materials for the inner lining in biomass gasifiers (63 and 85 weight percent Al2O3) have been exposed to three synthetic ashes, K2CO3-CaCO3-SiO2, K2CO3-CaCO3 and K2CO3 at 1050°C in CO2 atmosphere for 7 days in a muffle furnace to reproduce analogous chemical attack that would occur in a real gasifier. Samples were investigated with SEM-EDX for morphological and compositional effects and with XRD for crystalline phases at chosen distances from the exposed surface.

    A heterogeneous melt that prevented deep penetration of alkali was produced when Si was present in the ash composition. In the absence of Si, it turned out that only K was affecting the materials. K attacked the matrix and transported into the material and attacking grains. For the material containing more alumina potassium was found in continuously decreasing amounts down to 7-8 mm from the exposed surface. The other material showed a distinct border between affected and pristine matrix about 5 mm from the exposed surface. The affected part seemed to have been filled out and signs of expansion could be seen. The XRD analysis of the pristine and exposed refractories revealed significant differences. In the exposed ceramics the new phases; Leucite, Kalsilite, Kaliophilite, K(2-x)Al(2-x)SixO4 and Wollastonite were observed.

  • 341.
    Carlborg, Markus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Refractory corrosion in biomass gasification2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    To stop the net emission of CO2 to the atmosphere, we need to reduce our dependency of fossil fuels. Although a switch to a bio-based feedstock hardly can replace the total amount of fossils used today, utilization of biomass does still have a role in a future in combination with other techniques. Valuable chemicals today derived from fossils can also be produced from biomass with similar or new technology. One such technique is the entrained flow gasification where biomass is converted into synthesis gas. This gas can then be used as a building stone to produce a wide range of chemicals.

    Slagging and corrosion problems are challenges presented by the ash forming elements in biomass during thermochemical energy conversion. The high temperature in the entrained flow process together with ash forming elements is creating a harsh environment for construction materials in the reactor. Severe corrosion and high wear rates of the lining material is a hurdle that has to be overcome to make the process more efficient.

    The objective of this work is to investigate the nature of the destructive interaction between ash forming elements and refractory materials to provide new knowledge necessary for optimal refractory choice in entrained flow gasification of woody biomass. This has been done by studying materials exposed to slags in both controlled laboratory environments and pilot scale trials. Morphology, elemental composition and distribution of refractories and slag were investigated with scanning electron microscopy and energy dispersive X-ray spectroscopy. Crystalline phases were investigated with X-ray diffraction, and thermodynamic equilibrium calculations were done in efforts to explain and make predictions of the interaction between slag and refractory.

    Observations of slag infiltration and formation of new phases in porous materials indicate severe deterioration. The presence of Si in the materials is limiting intrusion by increasing the viscosity of infiltrated slag. This is however only a temporary delay of severe wear considering the large amount of slag that is expected to pass the refractory surface. Zircon (or zirconium) (element or mineral?) based material show promising properties when modeled with thermodynamic equilibrium, but disassembling of sintered material and dissociation of individual grains was seen after exposure to a Si- and Ca-rich slag. Fused cast materials have a minimal slag contact where the only interaction is on the immediate hot face. Dissolution was however observed when exposed to a silicate-based slag, as was the formation of NaAlO2 after contact with black liquor.

  • 342.
    Carlborg, Markus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Landälv, Ingvar
    Characterization of spent spinel-based refractory lining from a 3 MW black liquor gasifierManuscript (preprint) (Other academic)
    Abstract [en]

    Black liquor gasification is dependent on minimizing heat loss to the surroundings and thus needs to be well insulated. In combination with the high temperature and basic black liquor, a very corrosive environment is created on the hot face of such a reactor. Therefore the wall system is required to be chemically and thermally stable at the same time as it has insulating properties. These cannot easily be combined in the same material and therefore layers with different properties can be used in combination. Penetration of species through the lining can lead to further reactions with other construction materials, less suited for chemical resistance, corrosion of the pressure shell is an example with catastrophic consequences. This paper investigates two castable and one fused cast spinel (MgAl2O4) refractory after about 1 600 hours, and one fused cast material used for 15 000 hours of operation in a 3 MWth black liquor gasifier. Infiltration of Na, followed by destruction of microstructure, and extensive formation of NaAlO2 was observed throughout the whole castable materials, while it was mainly restricted to the hot face of the fused cast materials. Formation of NaAlO2 leads to a volumetric expansion which eventually lead to an increased pressure on the steel shell. In addition, the expansion of the bricks can cause stress and by that spallation and material loss.

  • 343.
    Carlborg, Markus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Kannabiran, Sankar
    Höganäs Bjuf AB.
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Interaction between ash forming elements in woody biomass and two high alumina refractories part 1: effects on morphology and elemental distributionManuscript (preprint) (Other academic)
    Abstract [en]

    To gain more knowledge about possibly destructive effects of ash-forming elements in woody biomass on refractory materials in entrained flow gasification, an exposure study was performed on two high alumina refractories. The materials, a pre-fired castable consisting of about 63 weight-% Al2O3, and a phosphate bonded brick with 83 weight-% Al2O3 was exposed to synthetic ash mixtures at 1050°C and 1 atm CO2 for 7 days. This paper presents distribution of ash-forming elements and morphology of the samples microstructure, while identification and distribution of crystalline compounds is presented in a separate paper. In the samples, potassium (K) had infiltrated the materials and reacted with different components, while calcium (Ca) did not seem to have any direct effect during these conditions. The matrix of the castable absorbed much K, became clogged and produced a distinct border between reacted and unaffected matrix. The coarser matrix of the phosphate bonded brick retained much of its porosity and had ash transported further into the material without a clear distinction between reacted and unaffected matrix. Grains with >30 atomic-% Si, formed a layer enriched in K, with a thickness up to 40 µm and cracks propagating through it. Grains mainly consisting of Al2O3 seemed unaffected by the exposure. When the ash was rich in SiO2, a melt was produced that restricted the attack on the refractories to the surface and coarser pores.

  • 344.
    Carlborg, Markus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Kannabiran, Sankar
    Höganäs Bjuf AB.
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Interaction between ash forming elements in woody biomass and two high alumina refractories part 2: transformation of crystalline compoundsManuscript (preprint) (Other academic)
    Abstract [en]

    Two high alumina refractories, one brick and one pre fired castable was exposed to pure K2CO3, K2CO3 + CaCO3, and K2CO3 + CaCO3 + SiO2 at 1050°C and a CO2 atmosphere. A stratified investigation of crystalline phases was made with polycrystalline x-ray diffraction, and thermodynamic equilibrium calculations were performed to explore possible formation paths. A monoclinic polymorph of KAlSiO4 was formed to a large extent in both materials exposed to pure K2CO3. Throughout the affected part of the castable and a small layer close to the surface of the brick, a solid solution between KAlO2 and KAlSiO4 formed, K1-xAl1-xSixO2, x = 0.19. The affected area of the castable had 30-50 %wt new phases and made a sharp transition to unaffected material. The concentration of new phases in the brick was decreasing at an even rate from about 40 to 15%wt throughout the whole material thickness of 14 mm. Exposure to K2CO3 and CaCO3 showed the same phases and behavior, but no Ca-bearing phases could be detected. The mixture containing K2CO3, CaCO3 and SiO2 did not penetrate far into the material but formed the same phases in the affected areas. Wollastonite (CaSiO3) formed in the slag on top of these materials. The major mechanism for formation of new phases is suggested to be the formation of an initial melt composed of K2O and SiO2. This liquid is then dissolving refractory components and forms a liquid in equilibrium with KAlSiO4 and K1-xAl1-xSixO2.

  • 345.
    Carlborg, Markus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Weiland, Fredrik
    Ma, Charlie
    Backman, Rainer
    Landälv, Ingvar
    Wiinikka, Henrik
    Exposure of refractory materials during high-temperature gasification of a woody biomass and peat mixture2018In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 38, no 2, p. 777-787Article in journal (Refereed)
    Abstract [en]

    Finding resilient refractory materials for slagging gasification systems have the potential to reduce costs and improve the overall plant availability by extending the service life. In this study, different refractory materials were evaluated under slagging gasification conditions. Refractory probes were continuously exposed for up to 27 h in an atmospheric, oxygen blown, entrained flow gasifier fired with a mixture of bark and peat powder. Slag infiltration depth and microstructure were studied using SEM EDS. Crystalline phases were identified with powder XRD. Increased levels of Al, originating from refractory materials, were seen in all slags. The fused cast materials were least affected, even though dissolution and slag penetration could still be observed. Thermodynamic equilibrium calculations were done for mixtures of refractory and slag, from which phase assemblages were predicted and viscosities for the liquid parts were estimated.

  • 346.
    Carlborg, Ylva
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Ash transformation during combustion of phosphorus-rich industrial sludge: Investigation of phosphorus recovery potential, and effects on emissions and deposit formation 2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Effective use of resources is essential in the development towards a sustainable industry. Waste products, such as sludge from industrial waste water treatment, often contain valuable reserves of plant nutrients but this resource is nonetheless commonly disposed of as contaminated waste.  Approximately 1 500 ton phosphorus per year is added in biological waste water treatment at the Swedish pulp and paper industries and this non-renewable resource thereby ends up in their so called biosludge. The most common way to discard the sludge is by incineration. Besides the high levels of phosphorus, the biosludge usually contains high levels of moisture and ash forming elements, sulfur and chlorine, which makes it a rather problematic fuel.

    The aim with this study was to investigate different aspects on ash transformation chemistry during co-combustion of biosludge, from the pulp and paper mill SCA Packaging Obbola AB, with wood fuels and wheat straw. The phosphorus recovery potential, and the effects on deposit formation and emissions,  were examined by SEM-EDS- and XRD-analysis of ash from co-combustion experiments. The experimental results were complemented with theoretical analysis based on thermochemical equilibrium calculations.

    The biosludge from SCA Obbola contained high levels of Ca which had a large impact on the ash transformation reactions. Most of the phosphorus from the fuels stayed in the solid ash during combustion, and in all ash assortments, except for the pure wood fuel, it was primarily found in the crystalline structure whitlockite, Ca9(K,Mg,Fe)(PO4)7. Hydroxyapatite, Ca5(PO4)3OH, was identified in ash from combustion of the pure wood fuel and wheat straw, and in the mixture of biosludge and wood fuels with the lowest proportion of sludge. Of the two phosphorus compounds, hydroxyapatite is more difficult to break down. It is therefore promising from a phosphorus recovery perspective that whitlockite was the main phosphorus compound in most of the ash assortments. Some of the sulfur in the sludge reacted with Ca and formed solid CaSO4, which stayed in solid ash during combustion, while chlorine generally left the bottom ash by volatilization.

    K- and Si-rich agricultural residues, such as wheat straw, are associated with a number of ash-related problems, including deposit formation due to low ash-melting points. During co-combustion of biosludge and wheat straw, the melting tendencies of the wheat straw ash elements were examined. According to the thermochemical equilibrium calculations, the composition of the mixed fuels would result in a significantly higher initial slag formation temperature compared to the pure wheat straw. This trend was also observed in the experimental results. It is likely that the relatively high levels of Ca, Al and P in the sludge all contributed to reduced slag formation in the wheat straw ash, by formation of ash compounds with higher melting temperatures. The high calcium levels may however have reduced some of the positive effects of increased P and Al contents by these elements preferably reacting with Ca instead of capturing alkali in crystalline structures.

  • 347.
    Carleborg, Mattias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Elanvändning i skolkök2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 348.
    Carlqvist, Freddy
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Studie och analys av energieffektiviserande åtgärder på sjukhus i Västra Götalandsregionen2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Västfastigheter är en av Västsveriges största fastighetsförvaltare och förser Västra Götalandsregionen med lokaler samt fastighetsförvaltning. Västra Götalandsregionen har som långsiktigt miljömål att halvera sin energianvändning i egna lokaler till år 2030 jämfört med år 1995. Ett led i att nå detta mål har varit att genomföra energikartläggningar på sjukhusbyggnader för att lokalisera energieffektiviserande åtgärder som kan genomföras för att reducera energianvändningen. Beskrivning av de energieffektiviserande åtgärder som föreslagits samt beräknad kostnad och energibesparing för dessa har dokumenterats i en databas. Energibesparingen för de energieffektiviserande åtgärderna i databasen har bland annat beräknats med simuleringsprogrammet IDA ICE.

    Syftet med detta examensarbete var dels att studera, strukturera och analysera det material som finns i databasen. Detta har gjorts genom att kategorisera de energieffektiviserande åtgärderna i databasen i tre huvudkategorier; driftoptimerande-, installationstekniska- samt byggnadstekniska åtgärder. Därefter har statistik för enskilda åtgärder tagits fram i form av medelvärde för respektive åtgärdskategori för att indikera vilka typer av enskilda åtgärder i databasen som ger den största energibesparingen samt är mest kostnadseffektiva. Resultatet från detta indikerar att de enskilda åtgärder i databasen som är av driftoptimerande karaktär är mest kostnadseffektiva, därefter följer installationstekniska åtgärder och sist åtgärder av byggnadsteknisk karaktär. För att även behandla de åtgärder som endast genomförs som åtgärder i åtgärdspaket, har kostnads- och energibesparingskurvor tagits fram för Skaraborgs Sjukhus Skövde (tidigare KSS - Kärnsjukhuset i Skövde). Resultatet indikerar att de åtgärder som förslagits för byggnad 4-6 samt 22-24 på KSS ger den största energibesparingen till lägst kostnad per sparad kilowattimme. Slutsatsen är att det är en god idé att ta fram liknande kurvor för de övriga sjukhusen, då dessa kurvor ger en indikation om vilka byggnader som bör prioriteras vid energieffektivisering.

    Syftet var även att undersöka hur en osäkerhet hos parametrar vid energibesparingsberäkningar påverkar resultatet samt undersöka interaktionseffekter för energieffektiviserande åtgärder. En modell av byggnad 16 på Södra Älvsbords Sjukhus i Borås har i detta examensarbete simulerats i IDA ICE för att undersöka inverkan av interaktionseffekter då flera energieffektiviserande åtgärder genomförs samtidigt. Resultaten indikerar att vid kombination av flera åtgärder uppstår i regel interaktionseffekter, vilket ligger i linje med andra studier. Vidare har det gjorts en känslighetsanalys, där det undersökts om osäkerhet hos köldbryggor, infiltration samt ventilationsflöde för en modell i IDA ICE påverkar den beräknade energibesparingen från energieffektiviserande åtgärder. Känslighetsanalysen visar att energibesparingen från energieffektiviserande åtgärder påverkas om det finns en osäkerhet i någon av de parametrar som justerats. Därmed är det viktigt att den modell som simuleras är rätt kalibrerad.

  • 349.
    Carls, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    NGN – Nästa Generations Nätverk (Nätverks- och Riskanalys) för Piteå Kommun2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    My mission has been to technical documentation and identify Piteå Municipality's existing network infrastructure. Everything has been summarized in several different areas: Network Services, Network-related services, Technology, Management/Control and Security. A risk analysis has been developed where I have identified a total of 28 risks and deficiencies in the municipality's existing network infrastructure. 4 risks and deficiencies under Design, 9 risks and deficiencies under Security, 5 risks and deficiencies under Network related services, 2 risks and deficiencies under Network Services, 2 risks and deficiencies under Management/Control and 5 risks and deficiencies under Technology. All risks and deficiencies have been categorized in order of low, medium and high risks and deficiencies of varying action time (0-24 + months). This final report has been the basis for then developing a new future-proof network infrastructure using a Requirements and Vision for the Municipality of Piteå.

  • 350.
    Carlsson, Gustav
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Alternativ bygglogistik för projekt i täta miljöer2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Several studies have shown that there is great potential for streamlining the construction process through better logistics. In the construction industry, it has long been considered the complexity that a construction project has that makes it difficult to get more efficient logistics. The project organization looks different for each project and the supply chains equally. The purpose of this project is to investigate which alternative logistics solutions that exist for construction projects in urban environments which means no room for materials storage on the site and require their deliveries just-in-time with high delivery precision. In the study, two case studies were conducted to investigate alternative solutions and how other companies have solved the problems.

    Storage of material outside the workplace of construction logistics centers and joint deliveries for contractors through third-party companies are possible alternatives for simplifying construction projects. The case studies show that the view of logistics differs depending on where in the country you are. Costs are reallocated to logistics personnel and third-party companies that handle large parts of the material flows instead of the craftsmen themselves. The challenges have been known for a long time in larger cities and methods have been developed based on the just-in-time principle to solve the problems.

    The result shows that flexibility and communication are the most important if one is to use a third-party logistics company within the construction industry. Digital tools play an increasingly important role as it is perceived to simplify and increase the collaboration between the contractors and the suppliers.

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