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  • 151.
    Azizi, Shoaib
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nair, Gireesh
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Olofsson, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analysing the house-owners’ perceptions on benefits and barriers of energy renovation in Swedish single-family houses2019In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 198, p. 187-196Article in journal (Refereed)
    Abstract [en]

    Single-family houses offer a large potential for energy savings by energy renovation (ER). Homeowners’ motivation to implement ER derives from the benefits and barriers they perceive. Benefits are the positive consequences that can motivate homeowners to act and barriers are the challenges that demotivate them to undertake ER. Different benefits and barriers do not homogenously affect every homeowner. Identifying motivating benefits and demotivating barriers for each specific group among homeowners can shed lights on ER decision-making and enable policies that are more effective. The objective of this study is to contextualize the implementation of ER by understanding how the perceived benefits and barriers influence homeowners. This study links the expected consequences, which are benefits and barriers to the influential factors on ER, which are used to group the homeowners.

    The analysis is based on a questionnaire survey mailed to 1550 owners of single-family houses in northern Sweden. The perceptions of homeowners on benefits and barriers of ER are significantly different between the groups that are motivated and unmotivated to implement ER. Despite the perceived importance of some of the benefits such as energy cost reduction, they may not be determinative for the homeowners’ decision to undertake ER. The homeowners are more likely to implement ER for reasons other than energy use reduction such as for improving the indoor environment. The barriers such as the difficulty of finding a low-interest loan and reliable information sources are found to impede the intention to implement ER among different groups. Policy implications to facilitate ER in single-family houses are discussed.

  • 152.
    Azizi, Shoaib
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nair, Gireesh
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Olofsson, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Demand-controlled energy systems in commercial and institutional buildings: a review of methods and potentials2019In: eceee 2019 Summer Study on energy efficiency:: Is efficient sufficient?, European Council for an Energy Efficient Economy (ECEEE), 2019, p. 1444-1450Conference paper (Refereed)
    Abstract [en]

    Heating, ventilation and air-conditioning (HVAC) are by farthe most energy intensive systems in commercial and institutionalbuildings with office spaces. This makes HVAC systemsattractive targets for energy efficiency improvement. New technologicaladvancements can play significant role on improvingenergy efficiency. Such advancements have been also emergedin form of novel management and control strategies, whichmight lead to considerable energy savings with relatively minorinvestments. This paper evaluates demand control HVAC andlighting to assess the energy saving potential of upgrading theconventional building energy systems.

    This paper provides a summary of different methods and occupancydetection technologies. A range of technologies andmethods are covered that vary in complexity, limitations andenergy saving potential. Additional benefits such as demandresponse are evaluated and other emerging applications arediscussed. Based on the review of methods and potentials, thepaper assesses the state of the art in demand controlled energysystems and suggests areas for further research.

  • 153.
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    MALIbase: Termodynamisk data för föreningar i systemet CaO-K2O-P2O52015Other (Other (popular science, discussion, etc.))
  • 154.
    Bagheri, Shahriar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Modeling, Simulation and Control System Design for Civil Unmanned Aerial Vehicle (UAV)2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Unmanned aerial systems have been widely used for variety of civilian applications over the past few years. Some of these applications require accurate guidance and control. Consequently, Unmanned Aerial Vehicle (UAV) guidance and control attracted many researchers in both control theory and aerospace engineering. Flying wings, as a particular type of UAV, are considered to have one of the most efficient aerodynamic structures. It is however difficult to design robust controller for such systems. This is due to the fact that flying wings are highly sensitive to control inputs.

    The focus of this thesis is on modeling and control design for a UAV system. The platform understudy is a flying wing developed by SmartPlanes Co. located in Skellefteå, Sweden. This UAV is particularly used for topological mapping and aerial photography.

    The novel approach suggested in this thesis is to use two controllers in sequence. More precisely, Linear Quadratic Regulator (LQR) is suggested to provide robust stability, and Proportional, Integral, Derivative (PID) controller is suggested to provide reference signal regulation. The idea behind this approach is that with LQR in the loop, the system becomes more stable and less sensitive to control signals. Thus, PID controller has an easier task to do, and is only used to provide the required transient response.

    The closed-loop system containing the developed controller and a UAV non-linear dynamic model was simulated in Simulink. Simulated controller was then tested for stability and robustness with respect to some parametric uncertainty. Obtained results revealed that the LQR successfully managed to provide robust stability, and PID provided reference signal regulation.

  • 155. Bagheri, Shahriar
    et al.
    Jafarov, Tural
    Freidovich, Leonid
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Sepehri, Nariman
    Beneficially Combining LQR and PID to Control Longitudinal Dynamics of a SmartFly UAV2016In: 7TH IEEE ANNUAL INFORMATION TECHNOLOGY, ELECTRONICS & MOBILE COMMUNICATION CONFERENCE IEEE IEMCON-2016 / [ed] Chakrabarti S, Saha HN, 2016Conference paper (Refereed)
    Abstract [en]

    The problem of control system design for longitudinal axis of a small-size flying wing is studied. The new controller proposed is comprised of two controllers working together to provide robust stability and step reference tracking for the nonlinear dynamics of SmartFly UAV. More precisely, Linear Quadratic Regulator (LQR) is used together with Proportional, Integral, Derivative (PID) controller. The inspiration comes from the fact that each of the mentioned controllers have advantages and disadvantages that cannot be neglected. LQR, as an optimal in terms of energy-like regulator, provides robust stability with a minimized energy-like performance index. It is also very computationally efficient. But, when it comes to the transient of particular output, LQR is not the best solution. On the other hand, PID has the advantage of a possibility to tune the gains for optimized transient behavior, especially for well-behaving plants. Furthermore, PID controller is particularly useful for tracking problems. However, PID is often not robust (in terms of parameter uncertainties) and it is also difficult to tune PID parameters for unstable systems. By differentiating between system stability and performance in the controller design process, it is possible to benefit from both controllers, using them along side together in one system. Functionality of this method was verified through computer simulation in MATLAB/SIMULINK for a nonlinear model of SmartFly UAV. Closed-loop system performance was evaluated in terms of robustness and step reference tracking.

  • 156.
    Bagir, Mohammad
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Konstruktion av broms till motståndsvagn2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Baltic fitness, which is the project owner, is a company that invests in Swedish-made training equipment. This work has been about constructing a resistance brake for a weight-bearing resistance sled, consisting of a chassis on wheels and four handles. Resistance sleds are often used for training purposes where the practitioner pulls or pushes the handles. In order for the exercise to have maximum effect the carriage must have some type of braking function that gives more resistance to the work and makes the work heavier.

     

    A preliminary study initiated the project to investigate various brake types and resistors used in vehicles and training equipment. Concepts for the brake function were designed with regard to the carriage construction and the requirements set by the project owner. Calculation have been made to ensure that the braking function creates sufficient resistance.

     

    The final result was two concept proposals, a magnetic resistance brake that acts like an electromagnetic retarder in heavy vehicles, without mechanical friction. The second concept is an electric resistance brake where an electric motor acts as a generator and a high load resistor loads the motor shaft.

  • 157.
    Bahtiri, Blerand
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    UX and Service Design for Zbee Based Corporate Carsharing2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    What transportation means corporations choose for satisfying their mobility needs may have an essential impact on the environment. Choosing environmental friendly, alternatives such as battery driven light electric vehicles, would mean drastically contributing to a more sustainable environment. Meanwhile as carsharing solutions, continuously rise in popularity together with other sharing economy business models so do their possibilities to satisfy the mobility needs for corporations either by them implementing their own carsharing service or by investing on external services offered by established carsharing operators. This thesis has investigated and designed for a Zbee based corporate carsharing service, to be used between the affiliates of Vinngroup in Gothenburg. A Zbee is a light electric three-wheeled vehicle. Based on user-centred service design methods, methods suggested for sharing economy solutions, as well as user experience design methods, this thesis identified that users have different individualistic needs in a workplace and prior experiences that affects how they will use the service.In order to satisfy these different needs, it was found, the system needs to provide real-time vehicle and scheduling information for ensuring the users vehicle availability and service reliability, being one of the first requirement from the users. Further the service should provide users with functions that help users through the different use phases that were identified during this work. The findings found were then presented visually by designing mobile application prototypes and testing them on participants iteratively. The final set of prototypes was further evaluated by using the System Usability Scale, an effective and popular tool for measuring the usability of products and services. This evaluation gave the scores 77.5, 92.5, 90, 87.5 and 72.5, thus this giving a mean-value of 84 and a median of 87.5. All these scores suggests the prototype has high usability.

  • 158.
    Baltz, Kim
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Mätning av Telias 4G-nät, Umeå universitets campusområde.2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report presents the results of the mesaurements I’ve made on Telias 4G-network in the form of data rate and signal strength, withing the vicinity of Umeå University campus. This report also includes basic theoretical information about the techonolgy behind a 4G-network. The mesaurements emanated from 304 different locations around the campus area, mesaurements were made through the application ”Bredbandskollen” on a mobilephone of the model Huaweii P7-L10.

    A second measurement was made during the fesitval called ”Brännbollsyran” on Campus between 26-28 of may. It’s purpose was to examine how the 4G-network handled a heavier strain, and compare it’s measurements to the first one.

    The conclusions that have been made are the following:

    • Telias 4G network lives up to the criteria concering coverage and speed they have stated.
    • The reception on the campus are is good, however inside it can be unreliable.
    • The network managed the strain during Brännbollsyran, and you could still use it sufficently, despite a heave load in the network.
  • 159.
    Barath, Stefan
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Mills, Nicholas L
    Lundbäck, Magnus
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Törnqvist, Håkan
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Lucking, Andrew J
    Langrish, Jeremy P
    Söderberg, Stefan
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Boman, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Westerholm, Roger
    Löndahl, Jakob
    Donaldson, Ken
    Mudway, Ian S
    Sandström, Thomas
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Newby, David E
    Blomberg, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Impaired vascular function after exposure to diesel exhaust generated at urban transient running conditions2010In: Particle and fibre toxicology, ISSN 1743-8977, Vol. 7, no 1, p. 19-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Traffic emissions including diesel engine exhaust are associated with increased respiratory and cardiovascular morbidity and mortality. Controlled human exposure studies have demonstrated impaired vascular function after inhalation of exhaust generated by a diesel engine under idling conditions.

    OBJECTIVES: To assess the vascular and fibrinolytic effects of exposure to diesel exhaust generated during urban-cycle running conditions that mimic ambient 'real-world' exposures.

    METHODS: In a randomised double-blind crossover study, eighteen healthy male volunteers were exposed to diesel exhaust (approximately 250 mug/m3) or filtered air for one hour during intermittent exercise. Diesel exhaust was generated during the urban part of the standardized European Transient Cycle. Six hours post-exposure, vascular vasomotor and fibrinolytic function was assessed during venous occlusion plethysmography with intra-arterial agonist infusions.

    MEASUREMENTS AND MAIN RESULTS: Forearm blood flow increased in a dose-dependent manner with both endothelial-dependent (acetylcholine and bradykinin) and endothelial-independent (sodium nitroprusside and verapamil) vasodilators. Diesel exhaust exposure attenuated the vasodilatation to acetylcholine (P < 0.001), bradykinin (P < 0.05), sodium nitroprusside (P < 0.05) and verapamil (P < 0.001). In addition, the net release of tissue plasminogen activator during bradykinin infusion was impaired following diesel exhaust exposure (P < 0.05).

    CONCLUSION: Exposure to diesel exhaust generated under transient running conditions, as a relevant model of urban air pollution, impairs vasomotor function and endogenous fibrinolysis in a similar way as exposure to diesel exhaust generated at idling. This indicates that adverse vascular effects of diesel exhaust inhalation occur over different running conditions with varying exhaust composition and concentrations as well as physicochemical particle properties. Importantly, exposure to diesel exhaust under ETC conditions was also associated with a novel finding of impaired of calcium channel-dependent vasomotor function. This implies that certain cardiovascular endpoints seem to be related to general diesel exhaust properties, whereas the novel calcium flux-related effect may be associated with exhaust properties more specific for the ETC condition, for example a higher content of diesel soot particles along with their adsorbed organic compounds.

  • 160.
    Barrestål, Sebastian
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nätverkslösningar och GPU-accelererad rendreringsfarm2017Independent thesis Basic level (university diploma), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    In this report a solution is created for a hypothetical company that works with digital design in motion- and still form. The report focuses on creating a comprehensive solution in the form of network-, server and computer equipment that is tailored to the customer. To know what type of hardware needed in various machines as a study on the subject conducted and the facts surrounding it are presented. The report contains a cost estimate for all equipment except regarding particular type of cabling.The conclusion is that when editing images and video, where the data size is 2GB, the use of a Graphical Processing Unit (GPU) acceleration in a renderingsfarm to make the work more effective. It is recommendedtwo different types of network attached storage(NAS) solutions for centralizing data storage within the company for more secure data by using Redundant Array of Independent Disks(RAID) and fast access times for ongoing projects that achieved by using Solid State Disks(SSD) paired with a high-speed network connection (10Gbit / s).

  • 161.
    Barsk, Tove
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Enhanced user experience for a digital travel service and associated intranet2017Independent thesis Advanced level (degree of Master (Two Years)), 300 HE creditsStudent thesis
    Abstract [en]

    The advance of the Internet, with its sophisticated algorithmic search engines, has made accessing information as easy as lifting a finger. Pre-trip travel planning can be considered a fundamental component of the trip experience. A traveler often needs to obtain important information in order to develop a travel plan. The objective of this thesis is to evaluate and enhance the user experience for a digital travel service and associated Intranet wich main function is to help travellers find departures, arrivals and prices.

    Based on an usability analysis, and user studies and support from a literature review this master theses resulted in a design proposal for Länstrafiken Norrbottens external website and their Intranet as well as a couple of guidelines for designing or redesigning a travel website.

  • 162. Basavoju, Srinivas
    et al.
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Velaga, Sitaram P.
    Indomethacin-saccharin cocrystal: design, synthesis and preliminary pharmaceutical characterization2008In: Pharmaceutical research, ISSN 0724-8741, E-ISSN 1573-904X, Vol. 25, no 3, p. 530-541Article in journal (Refereed)
    Abstract [en]

    Purpose. To design and prepare cocrystals of indomethacin using crystal engineering approaches, with the ultimate objective of improving the physical properties of indomethacin, especially solubility and dissolution rate. Materials and Methods. Various cocrystal formers, including saccharin, were used in endeavours to obtain indomethacin cocrystals by slow evaporation from a series of solvents. The melting point of crystalline phases was determined. The potential cocrystalline phase was characterized by DSC, IR, Raman and PXRD techniques. The indomethacin-saccharin cocrystal (hereafter IND-SAC cocrystal) structure was determined from single crystal X-ray diffraction data. Pharmaceutically relevant properties such as the dissolution rate and dynamic vapour sorption (DVS) of the IND-SAC cocrystal were evaluated. Solid state and liquid-assisted (solvent-drop) cogrinding methods were also applied to indomethacin and saccharin. Results. The IND-SAC cocrystals were obtained from ethyl acetate. Physical characterization showed that the IND-SAC cocrystal is unique vis-a-vis thermal, spectroscopic and X-ray diffraction properties. The cocrystals were obtained in a 1:1 ratio with a carboxylic acid and imide dimer synthons. The dissolution rate of IND-SAC cocrystal system was considerably faster than that of the stable indomethacin gamma-form. DVS studies indicated that the cocrystals gained less than 0.05% in weight at 98%RH. IND-SAC cocrystal was also obtained by solid state and liquid-assisted cogrinding methods. Conclusions. The IND-SAC cocrystal was formed with a unique and interesting carboxylic acid and imide dimer synthons interconnected by weak N-H center dot center dot center dot O hydrogen bonds. The cocrystals were non-hygroscopic and were associated with a significantly faster dissolution rate than indomethacin (gamma-form).

  • 163. Basavoju, Srinivas
    et al.
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Velaga, Sitaram P.
    Pharmaceutical cocrystal and salts of norfloxacin2006In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 6, no 12, p. 2699-2708Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to investigate the structural and pharmaceutical properties of norfloxacin ( a poorly soluble antibacterial drug), its cocrystal, and salts. Norfloxacin in the anhydrous form ( form A, 1) was crystallized. It was cocrystallized with isonicotinamide ( 2), and organic salts were prepared with succinic acid, malonic acid, and maleic acid (3-5, respectively). These phases were characterized by differential scanning calorimetry (DSC), infrared (IR) and Raman spectroscopy, and powder X-ray diffraction (PXRD). Single-crystal X-ray diffraction data were obtained, and crystal structures were solved. The apparent solubility of these phases was determined. Robust O-H center dot center dot center dot O, O-H center dot center dot center dot O-, O-H center dot center dot center dot N, N-H center dot center dot center dot O, N+- H center dot center dot center dot O-, and N-H center dot center dot center dot N interactions were present in all these structures. Quinolone moieties in these structures stack with pi...pi interactions and form channels to include CHCl3 or H2O. Herein we report a new cocrystal and salts of norfloxacin with improved aqueous solubility.

  • 164. Basavoju, Srinivas
    et al.
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Velaga, Sitaram P
    Pharmaceutical salts of fluoroquinolone antibacterial drugs with acesulfame sweetener2012In: Molecular Crystals and Liquid Crystals, ISSN 1542-1406, Vol. 562, no 1, p. 254-264Article in journal (Refereed)
    Abstract [en]

    Novel organic salts of norfloxacin and ciprofloxacin with artificial sweeteners such as saccharin and acesulfame were prepared. The two salts 1 and 2 were characterized by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). Finally, the crystal structures were solved by single crystal X-ray diffraction data and the structures were analyzed in terms of supramolecular synthons. In norfloxacin acesulfamate 1, two norfloxacin cations and two acesulfame anions form an eight membered cyclic tetramer supramolecular synthon. The salt, ciprofloxacin acesulfamate 2, has a similar structure as salt 1. This study contributes the importance of crystal engineering and supramolecular chemistry to the pharmaceutical applications in terms of interactions and structural correlations in the design of new solid phases. Supplemental materials are available for this article. Go to the publisher's online edition of Molecular Crystals and Liquid Crystals to view the free supplemental file.

  • 165.
    Bassem, Mohammad
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Förbränning av träpellets och pelleterad halm i en 40 kW rosterreaktor2012Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [sv]

    The project focus on combustion of softwood pellets and pellets in a 40 kW grate fire reactor at TEC-Lab. Dept Applied Physics and Electronics at Umeå University. Experiments were performed at four primary airs to fuel ratios (0.7 to 1.3), where aspects such as temperature profile, levels of gases (CO and NO), sintering-/-slagging and unburned fraction of the ashes were studied. Four different fuel loads were used for wood pellets (10, 20 and 30 kW) and one fuel load for straw (10 kW). Combustion of straw proved very difficult to ignite, and also led to other combustion-related technical problem such as slag formation due to the relatively low melting temperature-/-slag temperature of the straw. Causing undesired silicate melt on the grate. The straw was only possible to use low load operation (10 kW) because it was difficult to manage. The temperature of the bed varied between the studied cases with varying fuel loads and air to fuel ratios.

  • 166.
    Beckman Rehnman, Jeannette
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Ophthalmology.
    Lindén, Christina
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Ophthalmology.
    Hallberg, Per
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Behndig, Anders
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Ophthalmology.
    Treatment Effect and Corneal Light Scattering With 2 Corneal Cross-linking Protocols: A Randomized Clinical Trial2015In: JAMA ophthalmology, ISSN 2168-6165, E-ISSN 2168-6173, Vol. 133, no 11, p. 1254-1260Article in journal (Refereed)
    Abstract [en]

    Importance: We describe and evaluate a complementary method to indirectly quantify the treatment effect of corneal cross-linking (CXL). Additional methods to indirectly quantify the treatment effect of CXL are needed.

    Objective: To assess the spatial distribution and the time course of the increased corneal densitometry (corneal light backscatter) seen after CXL with riboflavin and UV-A irradiation.

    Design, Setting, and Participants: Open-label randomized clinical trial of 43 patients (60 eyes) who were 18 to 28 years of age and had progressive keratoconus and a plan to be treated with CXL at Umeå University Hospital, Umeå, Sweden. The patients were randomized to receive conventional CXL (n = 30) using the Dresden protocol or CXL with mechanical compression of the cornea using a flat rigid contact lens sutured to the cornea during the treatment (CRXL) (n = 30). All participants were followed up during a 6-month period from October 13, 2009, through May 31, 2012.

    Interventions: Corneal cross-linking according to the Dresden protocol or CRXL.

    Main Outcomes and Measures: Change in corneal densitometry after CXL and CRXL for keratoconus.

    Results: Of the original 60 eyes included, 4 had incomplete data. A densitometry increase was seen after both treatments that was deeper and more pronounced in the CXL group (difference between the groups at 1 month in the center layer, zone 0-2 mm, 5.02 grayscale units [GSU], 95% CI, 2.92-7.12 GSU; P < .001). This increase diminished with time but was still noticeable at 6 months (difference between the groups at 6 months in the center layer, zone 0-2 mm, 3.47 GSU; 95% CI, 1.72-5.23 GSU; P < .001) and was proportional to the reduction in corneal steepness (R = -0.45 and -0.56 for CXL and CRXL, respectively).

    Conclusions and Relevance: The degree of corneal light backscatter relates to the reduction in corneal steepness after cross-linking and may become a relevant complement to other methods in evaluating the cross-linking effect, for example, when comparing different treatment regimens.

    Trial Registration: clinicaltrials.gov Identifier: NCT02425150.

  • 167.
    Behndig, Annelie
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Mudway, IS
    Brown, JL
    Stenfors, Nikolai
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Helleday, Ragnberth
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Duggan, ST
    Wilson, SJ
    Boman, C
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Cassee, FR
    Frew, AJ
    Kelly, FJ
    Sandström, Thomas
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Blomberg, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Airway antioxidant and inflammatory responses to diesel exhaust exposure in healthy humans.2006In: European Respiratory Journal, ISSN 0903-1936, E-ISSN 1399-3003, Vol. 27, no 2, p. 359-365Article in journal (Refereed)
    Abstract [sv]

    Pulmonary cells exposed to diesel exhaust (DE) particles in vitro respond in a hierarchical fashion with protective antioxidant responses predominating at low doses and inflammation and injury only occurring at higher concentrations. In the present study, the authors examined whether similar responses occurred in vivo, specifically whether antioxidants were upregulated following a low-dose DE challenge and investigated how these responses related to the development of airway inflammation at different levels of the respiratory tract where particle dose varies markedly. A total of 15 volunteers were exposed to DE (100 microg x m(-3) airborne particulate matter with a diameter of <10 microm for 2 h) and air in a double-blinded, randomised fashion. At 18 h post-exposure, bronchoscopy was performed with lavage and mucosal biopsies taken to assess airway redox and inflammatory status. Following DE exposure, the current authors observed an increase in bronchial mucosa neutrophil and mast cell numbers, as well as increased neutrophil numbers, interleukin-8 and myeloperoxidase concentrations in bronchial lavage. No inflammatory responses were seen in the alveolar compartment, but both reduced glutathione and urate concentrations were increased following diesel exposure. In conclusion, the lung inflammatory response to diesel exhaust is compartmentalised, related to differing antioxidant responses in the conducting airway and alveolar regions.

  • 168.
    Behndig, Annelie
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Mudway, IS
    Brown, JL
    Stenfors, Nikolai
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Helleday, Ragnberth
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Duggan, ST
    Wilson, SJ
    Boman, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Cassee, FR
    Frew, AJ
    Kelly, FJ
    Sandström, Thomas
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Blomberg, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Airway antioxidant and inflammatory responses to diesel exhaust exposure in healthy humans.2006In: European Respiratory Journal, ISSN 0903-1936, E-ISSN 1399-3003, Vol. 27, no 2, p. 359-365Article in journal (Refereed)
    Abstract [sv]

    Pulmonary cells exposed to diesel exhaust (DE) particles in vitro respond in a hierarchical fashion with protective antioxidant responses predominating at low doses and inflammation and injury only occurring at higher concentrations. In the present study, the authors examined whether similar responses occurred in vivo, specifically whether antioxidants were upregulated following a low-dose DE challenge and investigated how these responses related to the development of airway inflammation at different levels of the respiratory tract where particle dose varies markedly. A total of 15 volunteers were exposed to DE (100 microg x m(-3) airborne particulate matter with a diameter of <10 microm for 2 h) and air in a double-blinded, randomised fashion. At 18 h post-exposure, bronchoscopy was performed with lavage and mucosal biopsies taken to assess airway redox and inflammatory status. Following DE exposure, the current authors observed an increase in bronchial mucosa neutrophil and mast cell numbers, as well as increased neutrophil numbers, interleukin-8 and myeloperoxidase concentrations in bronchial lavage. No inflammatory responses were seen in the alveolar compartment, but both reduced glutathione and urate concentrations were increased following diesel exposure. In conclusion, the lung inflammatory response to diesel exhaust is compartmentalised, related to differing antioxidant responses in the conducting airway and alveolar regions.

  • 169.
    Behring, Sven
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Kontaktpressningssystem: En studie av elsäkerhet2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    This work covers a broad analysis of the risks that could impact the achievement of electrical safety of electrical installations. The work includes both electrical equipment such as the installation of electrical equipment.The report illustrates the main technical characteristics of electrical connections greater than 10 mm2 and provides an introduction to the crimping systems for copper and aluminum conductors. In addition to that analyzes the factors that are important to assure the quality of an electrical connection throughout the value stream in terms of both materials such informations. Furthermore analyzed deeper the need for skills development of technicians and other staff.The different parts of this work are analyzed and presented, in theory to studies carried out both at Elpress AB and partly with the help of other scientific reports dealing with similar subjects. In addition, presents a survey that will help understanding the current perception of the electrical connections and cable crimping systems among end users. Various risks are analyzed in an FMEA analysis with respect to the different stages in the value stream.The project has shown that there is a need for changes in the regulations that deals with, among other things, permission for electrical staff.

  • 170.
    Bengtsson, Gustav
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Dimensionering av träförband: En jämförelse mellan olika typer av förbindare2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In timber construction, different metal dowel-type fasteners are used to attach members in timber frame construction. Therefore, in order to be able to choose a suitable fastener, you must know the differences between them and have knowledge of which rules to apply when calculating the load-carrying capacity.

    The purpose of this report is to show the differences in load-carrying capacity between different fasteners. This is done by comparing the load-carrying capacity of a connection with different fasteners. The focus has been on comparing the load-carrying capacity in ultimate limit state, but also other aspects such as mounting has been mentioned.

    The results show that if you want to maximize the load-carrying capacity of a connection, the best option is to use bolts in small dimensions. However, bolts with a diameter less than 10 mm are rarely used. In practical work, nails are often the best option if you want to maximize the load-carrying capacity. Screws have a lower load-carrying capacity than both nails and bolts for a connection with wood thickness up to 45 mm.

    In Eurocode 5, there are some sections that can be difficult to interpret and understand, for example the effective diameter and axial load-carrying capacity for screws. I have analyzed how the rules should be interpreted and my conclusion is that the interpretations differ also among professors and screw manufacturers. It can therefore be easier to use tabulated values for the load-carrying capacity from the manufacturer than to try to calculate it yourself.

  • 171.
    Bengtsson, Rikard
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Konceptdesign av redskapstilt anpassad för frontlastare: Utformning och tillverkning av prototyp för Ålö AB2016Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport beskriver utformandet av en redskapstilt konstruerad för frontlastare till jordbrukstraktorer. Redskapstilten är ett tillbehör vars syfte är att skeva redskapet i olika vinklar som är användbart vid markberedningar, pallmanövrering och liknande arbeten. Projektet genomförs på uppdrag av Ålö AB i Umeå som tillverkar både frontlastare och tillbehör till jordbrukstraktorer. Det långsiktiga målet för projektet är att ta fram en prototyp av en redskapstilt, samt att undersöka om det finns någon marknad för detta tillbehör till Ålös frontlastare. På grund av tidsbrist behandlar denna rapport endast framtagandet av konceptidén.Vid projektstarten genomfördes en marknadsundersökning för att ta reda på om redskapstilt för frontlastare, anpassad för jordbrukstraktorer, redan fanns tillgängligt på marknaden. Redskapstiltar är vanliga tillbehör för hjullastare och förekommer i tre olika koncept. De olika alternativen skiljer sig avseende på tiltfunktionens montage. Tilten kan vara monterad direkt på ett redskap, exempelvis fäst på en skopa med tiltfunktion. Den kan även byggas som en adapter, som enkelt kan monteras av och på lastarens redskapsfäste. Alternativt kan tilten byggas som ett helt nytt redskapsfäste med skevfunktion, som ersätter det befintliga redskapsfästet på frontlastaren.Med konceptstudien som grund listades de olika lösningsförslagens för- och nackdelar mot varandra. Det bästa alternativet visade sig vara ett redskapsfäste med skevfunktion, vilket kom att utgöra fokus för resten av projektet. Många olika faktorer vägdes in gällande redskapstiltens konstruktion under utformningen av lösningsförslaget. Krav som ställdes på konstruktionen var att infästningen till lastaren skulle stämma överens med befintligt redskapsfäste och anpassas efter Euro-typ. Dessutom skulle konstruktionen byggas med artiklar ur Ålös sortiment i största möjliga utsträckning, för att hålla tillverkningskostnaderna nere. Konstruktionen designades i CAD-programmet Solid Edge.Resultatet av projektet är en redskapstilt som i teorin uppfyller de för konstruktionen fastställda kraven. Konceptidén utgörs av en kompakt konstruktion, delvis bestående av komponenter från Ålös sortiment, som klarar simulerade kollisonstester med Ålös frontlastare. Fördjupade hållfasthetsberäkningar och ritningsunderlag kvarstår att genomföra innan en eventuell prototyptillverkning är aktuell.

  • 172.
    Bengtsson-Ölund, Robert
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Mäkeläinen, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Android och Linux på Beagleboard2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 173.
    Bennet, Anders
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utvärdering av rörelsesensor med ADXL345 accelerometer och ITG-3200 gyro2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Over the past years have you been able to see the advantage of doing motion analysis onpatients with impaired mobility. There are several different types of systems that can beused to perform a motion analysis and one of these systems are based on acceleration andangular velocity sensors. Systems based on acceleration and angular velocity sensors issomething that they on the Department of Biomedical Engineering at Norrland's UniversityHospital have seen the benefits of and is working with a project called AnyMo. Newsensors that can be used for motion analysis is in a constant development and sensorswhich is both cheaper and smaller than that one they are using today is coming out on themarket. The goal of this project is to test one of these new sensors and compare itsperformance against that one they are useing today. As part of the test a software and acircuit board will be build for a sensor from sparkfun (Digital IMU Combo Board - 6Degrees of Freedom ITG3200/ADXL345) and then compared with the current sensorADIS16350.The tests shows that the new sensor uses less power, is smaller and less expensive than theold sensor which is positive. But after analyzes test results from a measurement in which atest person did a shorter walk with both sensors so can you see that the result is not alwaysequal between the two sensors and that it is not possible to determine whether the resultsfrom the new sensor is better or worse than the results from the old sensor. More and othertypes of tests are necessary to obtain a more accurate measurement result.

  • 174.
    Berg, Mikaela
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Improving reading experience in digital newspapers2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Reading news on mobile devices has during the past decade transcended into an every- day activity, which induce greater demands on design and presentation of news. Several researchers have examined essential components in the area of digital newspapers, despite this, there are few newspapers that have switched to a reader-friendly format.

    The objective of this thesis is to evaluate how the reading experience in digital newspa- pers can be improved by abandoning the traditional structure of today’s printed newspapers. Based on numerous tests and studies, as well as support from literature, a set of guidelines has been produced as a result of this thesis.

    The design guidelines contain recommendations for optimal line size, typeface, point size, appearance, functionality, placement, recognition factor and packaging. To ensure quality, all guidelines were validated in order to prove that the reading experience had increased. An evaluation was performed that attempted to determine that.

    The statistic result of this thesis showed a significant difference in both reading speed and the subjective experience. However no significant difference could be seen regarding the reading comprehension. The conclusions made was that structure and design of content can influence both reading speed and reading experience.

    All design guidelines can be used as guidance when developing templates for digital newspapers. 

  • 175.
    Bergdal, Tobias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Teleskopisk redskapsbärare för hjullastare: Utveckling av en idé till en ny typ av hjullastarredskap2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Hjullastaren är en vanligt förekommande maskin på byggarbetsplatser. Där sköter den främst materialhantering och allmän logistik. De flesta husbyggen görs idag i fler våningar än enbart markplan och här begränsas hjullastarens konkurrenskraft av sin utformning då den inte klarar att leverera material till särskilt höga höjder. Detta arbete syftar till att utveckla en idé kring en ny typ av redskap vilket skulle ge hjullastaren möjlighet att utöka sin räckvidd vid materialhantering och därigenom öka sin konkurrenskraft jämte andra maskintyper.

    Arbetet har begränsats till utveckling av idén kring den nya redskapstypen varför frågor rörande lagkrav, säkerhet och dylikt har utelämnats.

    I arbetet har flertalet studiebesök genomförts hos olika återförsäljare, yrkesverksamma inom åkeri- och entreprenadbranschen och på byggarbetsplatser för att samla information om problemet och hämta inspiration till möjliga tekniska lösningar för den nya redskapstypen. En sammanställning av denna information har lett fram till den kravspecifikation som senare legat till grund för konstruktionen av redskapskonceptet. Hjullastarredskapet ska bland annat klara att tillsammans med hjullastaren ställa av material på ett par bockar på tredje våningens balkong (7,7 meter) samtidigt som den ska klara materialhantering under marknivå (-0,5 meter). Det sistnämnda eftersom redskapet ska erhållas användbart i nedförslutande mark. Den teleskopiska redskapsbäraren ska ha ett redskapsfäste med full funktionalitet för att kunna hantera vanligt förekommande hjullastarredskap både horisontellt och vertikalt mot marken. Redskapsbäraren ska dimensioneras för att klara en last av 2000kg. Som namnet antyder ska produkten även ha en teleskopisk funktion som ger ett smidigt och lätthanterligt redskap med god räckvidd.

     Utifrån kravspecifikationen och de önskade funktionerna på konceptet har skisser ritats. Dessa har legat som grund för de hållfasthetsberäkningar som gjorts och det efterföljande konstruktionsarbetet i Catia.

    Resultatet av arbetet har lett fram till ett koncept där den teleskopiska funktionen utgörs av två fyrkantsprofiler som ligger omlott om varandra. Dessa fästs in i en ”ram” tillverkad av fyrkantsprofiler. Längst ut på den rörliga teleskopbalken sitter ett Volvo L50 redskapsfäste för tillkoppling av hjullastarredskap.

    Konceptet uppfyller kraven ställda i kravspecifikationen samt de tippvinklar som behövs för att kunna hantera material på ett säkert sätt både i marknivå och uppe på höjder motsvarande tredje våningen.

    Avslutningsvis diskuteras designförändringar som skulle kunna bli aktuella om konceptet vidareutvecklas, t.ex. hur vikten och därigenom prestandan kan optimeras för redskapet genom att bland annat ta reda på aktuella spänningskoncentrationer genom FEM-analys och byte till ett klenare men lättare redskapsfäste.

  • 176.
    Bergenström, Rikard
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Höghöjdsanpassning av BvS10: Konceptstudie för optimering av överladdningssystem2014Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [en]

    This report relate a concept study that consider a number of different proposals to improve the overcharging system in BAE Systems Hägglunds tracked vehicle series BvS10, to maintain sealevel power at extreme altitude.

    At high altitude the power losses beacuase of the air density that decreases, which results in less fuel can be burned. The decreasing of air density also gives rise to fatigue failure of the turbocharger unless power is reduced.

    The proposals shall be as required by BAE Systems Hägglunds economically sustainable and defensible from a packing perspective. That means the selected solution must have a reasonable price tag and at the same time a minimal impact on adjacent components.

    The basis for this thesis is based on benchmarking of both the auto industry as the flight industry, to find inspiration and tips for improvement.

    Some of the concepts have after gathering facts and calculations been excluded while other solutions has been considered as workable and thus interesting for BAE Systems Hägglunds.

    Initially the current turbochargingsystem was analyzed in order to determine the starting point and thus be able to fix the current problems surrounding high altitude driving. Since then, various concepts has been studied in form of single turbocharger, twostage turbocharging, turbocharger-supercharger compound, material exchange of impeller and engine optimization.

    The solution that is concidered to works especially well for BAE Systems Hägglunds tracked vehicle series, is to complement the current turbocharging setup with a centrifugal supercharger. 

  • 177.
    Berggren, Oscar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    COMSOL Multiphysics - Ett energitekniskt analysverktyg vid numerisk simulering av köldbryggor och analys av fukt i konstruktionesdetaljer2014Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [en]

    Berggren, O. (2014) COMSOL Multiphysics – An analysis tool for energy applications when conducting numerical simulations on thermal bridges and analysis of moisture in construction details. Master thesis in Energy Engineering. Department of Applied Physics and Electronics at Umeå University.

    The consultant company Tyréns has at its office in Umeå decided to evaluate the application of the software COMSOL Multiphysics.  The evaluation consisted of a simulation on an energy engineering problem with its origin from a project at Tyréns, performed in COMSOL Multiphysics.

    The chosen project for this task was a part of the design plans of the culture house Väven in Umeå. These design plans includes the analysis of a thermal bridge and moisture on a variety of construction details, where one of them was selected to be investigated further.

    The main purpose of the investigation was to analyze if the results obtained from the simulations performed in COMSOL Multiphysics were equivalent compared to the results from the design plans. The investigation also included the presentation of an overall cost estimation for the software COMSOL Multiphysics.

    The obtained results from the analysis of the thermal bridge and moisture in the construction were in both cases slightly raised compared to the results from the design plans, in average an increase of 20 %.

    The work undertaken concludes that there is fully possible to recreate the previously executed simulations extracted from the design plans in accordance to the requirements and standards that are set. The obtained results are equivalent, even though a minor difference, compared with the results from the design plans and are valid too be used in a real life scenario.

    The obtained conclusions are that it is possible to prevent moisture in the construction detail. However, the overall U-value, , indicates that the energy efficiency of the entrance square is not good enough to reach the requirements of the SNBBP (Swedish National Board of Housing, Building and Planning). Even though the U-value for the construction detail, , can be assumed to meet the criteria’s of the SNBBP.

    Due to the fact that the simulations were conducted with COMSOL Multiphysics without any major problems and provided valid results, it is considered that the software is an appropriate tool to perform simulations at Tyréns. However, the cost for a floating license of the software Flixo is much less then for COMSOL Multiphysics. COMSOL Multiphysics is at the time of this study four times as expensive as Flixo. COMSOL Multiphysics has though an advantage because it can treat problems with a multiphysical nature in one, two and three dimensions with the use of only its standard edition. To ensure that the use of COMSOL Multiphysics can be economical viable, it is necessary that the software is used in multiple applications besides performing simulations on thermal bridges and moisture in construction details.           

  • 178.
    Berggren, Thor
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys av värmesystem, förslag på effektiviseringar för att värma vatten/ballast för   modulära betongstationer2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this thesis I examine the potential to recover some of the heat used to warm up ballast when the material is stored in ballast tanks, at an industrial sized concrete facility at outdoor temperatures below +5 °C. Three different cases with different heating applications are covered. All calculations has been made using 0 °C as outdoor temperature, results with varying outdoor temperature is shown in graphs at the end of the results chapter.

    Case 1, where the ballast is heated with humidified flue gas has a calculated estimated output of 506 kW, of these 506 kW, 67.5 kW can be recycled, which means that the theoretical percentage of recyclable power is 13.4%. Furthermore, the calculations show that the inlet temperature drops from 300 °C to 162 °C just above the ballast. The time for heating the material is in this case 5 minutes.

    Case 2, where the ballast is heated with dry hot air at a calculated estimated output of 10 kW, of these 10 kW, 7.6 kW can be recycled, which means that the theoretical percentage of recyclable power is 76.3%. Furthermore, the calculations show that the inlet temperature drops from 100 °C to 78 °C just above the ballast. The time for heating the material is in this case 16 hours.

    Case 3, where the ballast is heated with humidified air has a calculated estimated output of 85.3 kW, where all power is used to heat the ballast. The case is shown to work with a deficit of energy which means the ballast could absorb a lot more power than is actually available. Therefore, the percentage of recoverable energy is 0 %, and consequently the inlet temperature drops from 100 °C to 0 °C

  • 179.
    Bergius, Lina
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Sulfatmätningar i kokeriet2015Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    This work has been performed in the digester at Domsjö Fabriker in order to clarify the concentration of sulphate-ions comparing to different driving-conditions in the process. The reason to this is to understand and be able to avoid conditions in the digester process that means very high concentrations of sulphate-ions. The work is included in the examination of higher education: process operator at Umeå University.At Domsjö Fabriker similar studies have been done in the digester and from that it has been found out that the concentration of sulphate-ions is connected to pH and over time. The purpose is to approve the understanding of the process conditions to avoid extremely high concentration of sulphate-ions. The mission with this work and the measurements included in the work is to put together results that show when the concentration of sulphate-ions is high. The procedure of the study has consisted in taking samples in series of four, frozen the samples and finally analyzing them by titration and pH-measurements.After 22 evaluated trial-series á four samples each from the boilers it was concluded that the concentration of sulphate-ions was the greatest in the end of this process-step. The pH was upper and the concentration of sulphate lower in the first sample. None of the data is abnormal in any way, and they are all connected and relevant to each other. In this experiment it is not possible to state if the concentration of sulphate is affected by the pH or not.

  • 180.
    Berglund, Anton
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Digital screen for appointments and employees2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With a digital screen a company can provide a simple way to inform its employees and visitors about what is going on at the oce. The company KnowitAB wished to be able to display upcoming events through such a digital screen.This thesis describes how a solution was designed and implemented to suit the needs of the company.By using the design process a web based solution was built able to display events retrieved from the company's Exchange server on a digital screen. The solution was also built as a web site, making it accessible from outside the office so that employees can look up information on the go. The resulting solution is going to be installed in Knowit's office in Umeå, with a future vision of installing it in several other Knowit offices.

  • 181.
    Berglund, Beatrice
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys av dimensionerande temperaturer från värmeåtervinningsbatteri till frånluftsvärmepump2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    There are a large number of houses that have no heat recovery in the ventilation systems at present. There is an option to install heat recovery batteries to the exhaust air ducts that is connected to heat pumps in order to meet energy reduction targets for 2020 and 2050.

    The purpose of this project has been to investigate how energy consumption and annual cost depends on the design temperatures of the heat recovery battery. The parameters that have been investigated are normal variations of:

    -          Exhaust air temperature

    -          The moisture content in the exhaust air

    -          Exhaust air flow over battery

    -          Liquid flow over battery

    The overall coefficient of performance (COP) of the system has been studied for heat pumps with or without variable speed. The efficiency has also been investigated when solar panels are connected to the system.

    Two batteries have been simulated, a traditional battery from Luvata and one needle pipe battery from Retermia. The two heat pumps which have been investigated are one heat pump from IVT and one industrial heat pump with speed control from Kylma.

    Calculations and simulations have been made in the program Coils and Microsoft Excel.

    The cases that have been investigated are:Case 1: Luvata battery connected to Kylma heat pumpCase 2: Retermia battery connected to Kylma heat pumpCase 3: Luvata battery connected to IVT heat pump

    A comparison of annual costs for heating water with a heat pump system or with district heating was made.

    The results from the calculations for the batteries show that the Luvata battery can absorb more heat than the Retermia battery in most cases, because of its higher temperature efficiency, about 81 % compared to 71 %.

    The COP for Kylma were shown between 3.9 and 4.1 and for IVT between 2.6 and 2.8. Case 1 and case 2 will have the best options with a total COP of about 3.8 for every parameter variation, while case 3 gives a total COP of about 2.5 for every parameter variation, when the total COP of the system were calculated.

    In the calculations of which case that is most profitable the answer is case 2, with an annual cost divided by the produced thermal energy about 390 kr/MWh compared to the case where a district heating exchanger were installed about 640 kr/MWh.

    The total COP and the annual costs can be concluded that case 2, when Retermia battery is connected to a Kylma heat pump, is the best option based on the calculations that has been performed.

  • 182.
    Berglund, Beatrice
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys av dimensionerande temperaturer från värmeåtervinningsbatteri till frånluftsvärmepump2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Det finns i dagsläget ett stort antal bostadshus som inte har någon värmåtervinning i ventilationssystemet. För att uppnå energiförbrukningsmålen till 2020 och 2050 är ett alternativ att sätta in värmeåtervinningsbatterier i frånluftskanaler som ansluts till en värmepump.

    Syftet med detta projekt har varit att undersöka hur energiförbrukning och årlig kostnad påverkas av temperaturer från värmeåtervinningsbatteri. Parametrarna som har undersökts är normala variationer av  Frånluftstemperatur, Fukthalt i frånluft, Frånluftsflöde genom batteri resp. Vätskeflöde genom batteri.

    Utöver detta har även totalvärmefaktorn för anläggningen undersökts beroende på om det är en varvtalsreglerad värmepump som används jämfört med en värmepump med steg samt hur totalvärmefaktorn har påverkats när solfångare ansluts till systemet.

    Vid beräkningar och simuleringar har två värmeåtervinningsbatterier undersökts, ett traditionellt batteri från Luvata och ett nålrörsbatteri från Retermia. De två värmepumparna som har undersökts är en fastighetsvärmepump från IVT och en industrivärmepump med varvtalsreglering från Kylma. Dessa beräkningar och simuleringar har utförts i programmet Coils och Microsoft Excel.

    De fall som har undersökts är:Fall 1: Luvata-batteri anslutet till Kylma-värmepumpFall 2: Retermia-batteri anslutet till Kylma-värmepumpFall 3: Luvata-batteri anslutet till IVT-värmepump

    För att få en bild av hur lönsamt det är att värma tappvatten med värmepump kontra fjärrvärme har fjärrvärmepriser och elpriser jämförts. Dessutom har vilket av fallen som ger den lägsta årliga kostnaden beräknats.

    De resultat som fås när värmeåtervinningsbatterierna jämfördes utifrån simuleringar och beräkningar var att Luvata-batteriet kan tillgodogöra sig mer värme jämfört med Retermia-batteriet i de flesta parametervariationerna eftersom dess temperaturverkningsgrad ligger något högre, cirka 81 % jämfört med 79 %.

    COP-värden för Kylma-värmepumpen har beräknats vara mellan 3,9 och 4,1 och för IVT-värmepumpen mellan 2,6 och 2,8. Vid beräkning av totalvärmefaktor för anläggningen blev fall 1 och 2 de bästa alternativen med en totalvärmefaktor på cirka 3,8 medan fall 3 gav en totalvärmefaktor på cirka 2,5.

    Vid beräkning av vilket alternativ som är mest lönsamt gav fall 2 den lägsta årliga kostnaden per producerad värmeenergi på cirka 390 kr/MWh jämfört med fallet där en fjärvärmeväxlare installeras på 640 kr/MWh.

    Utifrån de beräkningar som gjorts för både totalvärmefaktor och ekonomi kan slutsatsen dras att fall 2, när Retermia-batteri är kopplat till en Kylma-värmepump, är det bästa alternativet.

  • 183.
    Berglund, Joel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    THE PROSPECT OF LIVING FILTERS: Reducing building sector energy demands by improving indoor air quality2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today people spend all the more time indoors. Asthma, allergies and Sick Building Syndrome (SBS) are affecting an increasing number of people. The remedy for all these affections has long been to increase the volume flow of outdoor air in the ventilation but at the same time cities all over the world are struggling with air pollution and smog rising above endangering levels. Living filters present a new solution where part of the indoor air can be purified and recirculated in a building. This project has compiled research on the area to describe the how and why concerning air purification by plants. Independent research conclude that plants can reduce most hazardous chemical agents in the air.

    Climate change, global warming and increasing demands on energy performance induces a race for countries and companies to improve energy efficiency in all sectors. To the building engineering sector living filters presents a unique solution to cut ventilation energy loses. A powerful simulation tool IDA ICE was used to estimate the energy saving capacity when a living filter is applied in the lunch room of an office floor. Another simulation software; Comsol Multiphysics was used to illustrate the aspects of ventilation flow when a living filter cabinet is deployed in a room. The simulation results show that for three living filter cabinets each measuring 0,7x0,8x1,73 cm the buildings energy usage is reduced with more than the living filters use to operate. The single room simulations then show how a living filter can be accommodated with both mixing and displacing ventilation. However, these simulations also illustrate the importance of the living filters placement to achieve maximum ventilation efficiency. 

    The conclusions from this work are that living filters can reduce building sector energy demands and provide significant indoor environmental benefits. The main issue for using living filters is identified to be building regulations putting strict demands on outdoor air flow and that the hygienic function of each living filter must be verified before it may replace outdoor air.

  • 184.
    Berglund, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Projekterings- och granskningsförbättringar: Identifiering av brister och förbättringsförslag för dessa i projekterings- och granskningsprocessen av arkitekthandlingar2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Fastec Sweden AB specializes in turnkey contracts of sports centers, industrial and commercial buildings. The overlap between design and production in turnkey contracts makes the process sensitive to defects and shortcomings in construction documents. Therefore, Fastec wants to investigate its shortcomings in the design and review process of architectural documents and see what can be improved. The purpose of the thesis is thus to identify possible shortcomings and deliver adapted proposal routines and improvement proposals for Fastec Sweden.

    For the identification of possible shortcomings, three projects have been selected to be reviewed, they´ve been projected by internal and external architectual planners and led by project managers at Fastec in Skellefteå. Documents that form the basis for and completed architectural documents have been reviewed, as well as deviation reports from the worksite. Interview talks and discussions with participants in the projects as well as other experienced and knowledgeable employees from the organization have been completed. Even previous projects evaluation documents and general shortcomings in the design work have been discussed in the interview talks.

    The resulting most frequently identified shortcomings are partly the agreement and the choice of external consultants and shortcomings in the target image that the design should work for, ie. what the production expects from the architectural documents. The design of doors and associated formation drawings and the use of too many wall types in the projects is also a common problem. So is the lack of utilization of the drawing and review programs the organization has at its disposal, as well as the low frequency of feedback and deviation reporting from the worksites.

    Proposals and improvement measures based on identified shortcomings can be found at the end of the thesis. Those who this thesis have come to the most frequent and important to change is to create a clearer target image for the early stage of the design process together with the other participants in the projects, especially the production management. To clearify what level of detail is expected of the construction and architectural documents. Rationalize the design with functional descriptions for door suppliers who are required to complete the design, as well as utilize capacity on a larger scale than today in the CAD and reviewing programs available to the organization.

  • 185.
    Berglund, Sofia
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Projekt- och produktionsledning för ett effektiviserat arbetssätt på en PR-byrå2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Almost everyone in today’s society is in contact with projects (Tonnquist, 2010). At the sametime, the idea of what project management is often gets misunderstood. The interest forproject management and public relations lad the bases for this examination work. This is astudy that aims to improve the efficiency in projects at a PR agency. A couple of mainquestions were prepared to reach the purpose. These include how an agency is working withthe project process compared to theories, also the workflow and how ideas are developed ishighlighted to improve the efficiency.This study describes the traditional and the agile approach to provide an objective view ofhow projects could be carried. The method has then been qualitative with simplistic interviewsand observation at a case-agency. The goal has been to see the connections betweentheory and reality in order to give recommendations for a more efficient project work.The result of this study identifies some similarities between theory and reality. Trends inboth agile and traditional where seen. Though the result mainly showed a lack of structureand that the case-agency doesn’t work with a common strategy for project processes.The agency is given the recommendation to apply a structured version of both the traditionaland the agile approach. Then setting up a system for selecting. A project that is clearly drivenby the customer gets the traditional project approach. Clients that do know what they wantto achieve, but not how, gets projects with an agile approach. Another recommendation is togain a structured process for how to generate ideas. Less extensive recommendations inareas such as time management and prioritization where also presented. The efficiency issummarized in the application of the Lean philosophy, to eliminate everything that does notprovide benefits to the customer.The most relevant finding from this study is that project management is like life. There aremany different theories on how it can or should be done, but in the end it’s up to everyone tocreate their own way of doing it. Although the selected route should be at least reasonablystructured.

  • 186.
    Berglund, Stefan
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Mejtoft, Sara
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Stärkt yrkesidentitet genom förändrad program-och kursstruktur med avseende på generiska färdigheter2015In: Universitetspedagogiska konferensen 2015: Gränslös kunskap, Umeå: Umeå universitet , 2015, p. 12-14Conference paper (Other academic)
  • 187.
    Bergman, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energikartläggning av en kontorsfastighet samt analys av energibesparande åtgärder.2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Detta projekt utfördes på uppdrag av Balticgruppen Fastigheter. Energikartläggningen omfattar kontorsbyggnaderna Pinnen och Struten som ligger på adresserna Kylgränd 4-6 i Umeå, Sverige. Syftet med projektet var att genom en energikartläggning och energibalans finna och utvärdera ekonomiskt hållbara energibesparande åtgärder som kan minska energianvändningen. I projektet ingick också att undersöka de olika abonnemangen för fjärrvärme och el och undersöka hur kostnaderna för dessa påverkas av de energibesparande åtgärderna.

    Arbetet inleddes med att med hjälp av energistatistik och inventeringar kartlägga all energianvändning i fastigheten. Energikartläggningen användes sedan för att definiera byggnaden i IDA ICE och simulera energibalansen. Med hjälp av energikartläggningen, energibalansen och personal från Balticgruppen Fastighet valdes ett antal åtgärdsförlag ut för att titta närmare på. Dessa var:

     ny motorvärmarstyrning

     ny utebelysning

     byte av lysrörsarmaturer i kontor

     ljus- och aktivitetsstyrning av kontorsbelysning

     byte av luftbehandlingsaggregat

     byte av fläktar i aggregaten

     byte till fläktar med styrning efter temperatur och CO2-halt

    I nästa steg beräknades lönsamheten för de olika åtgärdsförslagen med internräntemetoden. Utifrån de ekonomiska beräkningarna valdes ett åtgärdspaket ut som bestod av ny motorvärmarstyrning, ny utebelysning, byte av luftbehandlingsaggregat och ljus- och aktivitetsstyrning av kontorsbelysningen.

    Energibesparingen för styrning av motorvärme och byte av utebelysning påverkar inte uppvärmningen av fastigheten men uppskattades ge en elbesparing på 108 MWh/år. Byte av luftbehandlingsaggregat och styrning av kontorsbelysning beräknades minska fjärrvärmen med 495 MWh/år, elanvändningen med 100 MWh/år och fjärrkylan med 20 MWh/år. Investeringskostnaden för åtgärdspaketet uppskattades till 6 370 000 kr och den årliga besparingen till 620 000 kr/år. Detta resulterade i en internränta på strax över 8 % vilket betyder att investeringen är ekonomiskt lönsam. Resultaten visade även att två av elabonnemangen bör dimensioneras ned.

  • 188.
    Bergman, Jonathan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Technical Solutions in Dimensioning an Industrial Torrefaction Facility2017Independent thesis Advanced level (degree of Master (Two Years)), 300 HE creditsStudent thesis
    The full text will be freely available from 2022-05-31 15:55
  • 189.
    Bergner, Lukas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utredning av påbyggnad för befintligt sjukhus tillhörande NUS2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    VLL (Västerbotten County Council) is currently going through a process where they review their real estate on NUS (Norrland University Hospital) with a focus on its future development and requirements. One step in this process is to examine existing real estate and analyze if development is possible before there can be necessary to expand the area. One part of this project is consequently to investigate a possible extension of a building with two parallel buildings 10A and 10B, which today consists of three operative levels with a common basement. This study assumes that it is statically possible to build on the current building components. Therefore, the aim of this project is mainly to see if it is practical to implement an extension with respect to an adjacent helipad, ongoing operatives and a functioning APD-plan where the focus lies on crane placement. And also to construct a stage classification and associated production method. All this in order to develop existing real estate on NUS without the primarily need to expand into undeveloped real estate. The method which is used to reach the project goal was to establish a task list and formulate specific questions about each activity. Then an employee of VLL answered questions in simple forms of meetings or referred to another person or to a material that was relevant. In other situations, information gathered directly from websites. After each part of the project a conclusion and recommendation has been made to choose a solution, so that the next part of the project can proceed based on previous elections. The project has resulted in an extension of the buildings 10A / B that have been possible to perform regarding the investigated areas. A framed structure of wood result that 10A should be expanded with four floors and 10B with two floors. This, with an additional extra gross floor area totaling 9,140 m2

  • 190.
    Bergsten, Daniel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Modellering och analys av sekundärvärmesystemet på Iggesunds bruk2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Iggesund Paperboard AB är ett företag inom Holmenkoncernen med verksamhet i Iggesund och årligen produceras över 300 000 ton kartong. För att minska användningen av fossila bränslen har företaget investerat i en ny sodapanna vilket har skapat nya förutsättningar i fabrikens sekundärvärmesystem som tar hand om fabrikens spillvärme.

    I detta projekt har möjligheterna att minska vatten- och energianvändningen i fabriken analyserats genom att studera fabrikens sekundärvärmesystem. Utifrån ritningar samt information från fabrikens loggsystem skapades en simuleringsmodell med modellverktyget Extendsim. Detta för att analysera hur hetvattenbehovet i sekundärvärmesystemet kan täckas när hetvattenproduktionen minskar från stripperkolonnen. I modellen undersöktes även den ökade fjärrvärmepotentialen i filtratvatten från blekerier och hetvattenöverskott då blekerierna moderniseras i fabriken. Projektet är ett examensarbete i civilingenjörsprogrammet i energiteknik på Umeå universitet, och har utförts under hösten 2014.

    Resultatet visar att den minskade hetvattenproduktionen från kondensorer vid stripperkolonn kan kompenseras med ökad hetvattenproduktion från kokerikylare samt varmvatten från rökgasskrubber då ånga från stripperkolonn istället används till lutförvärmning.

    Det primära ångbehovet minskar med 23 900 ton per år då ånga från stripperkolonn används till lutförvärmning. Detta leder till 5,17 MSEK i minskade kostnader för företaget med ett ångpris på 216 SEK/ton, och gör en investering i regleringsutrustning lönsam med en återbetalningstid på 0,9 månader.

    Investeringarna i och med modernisering av blekerierna har en liten påverkan på den totala råvattenanvändningen i sekundärvärmesystemet, dock minskar vattenanvändningen i blekerierna vilket ökar möjligheterna att använda sekundärvärme till andra områden. När samtliga åtgärder i blekeriet är genomförda är fjärrvärmepotentialen i filtratvatten och hetvattenöverskott 21 MW och kan värma en fjärrvärmeprimär upp till 68 °C.

  • 191.
    Bergsten, Mathias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Behovsstyrdventilation för en befintlig kontorsfastighet: )  En LCC-jämförelse mellan DCV och CAV2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Demand controlled ventilation has in this study been investigated in a life cycle cost (LCC) - perspective for an existing office property. The goal was to examine whether a complementary of the existing constant air volume (CAV)-system to a demand controlled ventilation (DCV) -system is profitable.

    This project has been executed on behalf of Fastpartner AB. The studied property is an office building of floor area 6000                          in Stockholm, Sweden.

    Two different types of DCV systems were analyzed: C controlled ventilation and C with temperature controlled ventilation. The software IDA ICE was used in order to examine the energy consumption for district heating, district cooling and electricity for the air handling unit.

    The building has been modelled as accuracy as possible in order to represent the real building. In order to see the effect of various loading rate, simulations with three different occupancy levels for CAV and the DCV-systems was made. The occupancy levels represented organizations with high, low and medium occupancy. In the end nine simulations was made.

    The net present value method was used for each system in the LCC analyses. Costs for installation, purchase and maintenance have been taken into account. The results from the study showed that both of the DCV-systems gives a lower LCC than the existing CAV- system. The most profitable DCV-system is C with temperature- controlled ventilation, that presents a theoretical cost saving up to 250 000 kr.

    The variation of occupancy levels didn’t affect the outcome of LCC for C and temperature controlled ventilation, however C controlled ventilation showed a significant difference depending on low versus high occupancy level. Low occupancy level results in a higher cost saving.

    The fans for the air handling unit had the largest energy saving based on energy sector. Where a reduction up to 75 % can be achieved for C controlled ventilation at low occupancy level.

  • 192. Bergström, Dan
    et al.
    Israelsson, Samuel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Öhman, Marcus
    Dahlqvist, Sten-Axel
    Gref, Rolf
    Boman, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Wästerlund, Iwan
    Effects of raw material particle size distribution on the characteristics of Scots pine sawdust fuel pellets2008In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 89, no 12, p. 1324-1329Article in journal (Refereed)
    Abstract [en]

    In order to study the influence of raw material particle size distribution on the pelletizing process and the physical and thermomechanical characteristics of typical fuel pellets, saw dust of Scots pine was used as raw material for producing pellets in a semi industrial scaled mill (similar to 300 kg h(-1)). The raw materials were screened to a narrow particle size distribution and mixed into four different batches and then pelletized under controlled conditions. Physical pellet characteristics like compression strength, densities, moisture content, moisture absorption and abrasion resistance were determined. In addition, the thermochemical characteristics, i.e. drying and initial pyrolysis, flaming pyrolysis, char combustion and char yield were determined at different experimental conditions by using a laboratory-scaled furnace. The results indicate that the particle size distribution had some effect on current consumption and compression strength but no evident effect on single pellet and bulk density, moisture content, moisture absorption during storage and abrasion resistance. Differences in average total conversion time determined for pellet batches tested under the same combustion conditions was less than 5% and not significant. The results are of practical importance suggesting that grinding of saw dust particle sizes below 8 mm is probably needless when producing softwood pellets. Thus it seem that less energy could be used if only over sized particles are grinded before pelletizing.

  • 193. Bergström, Dan
    et al.
    Israelsson, Samuel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Öhman, Marcus
    Dahlqvist, Sten-Axel
    Gref, Rolf
    Boman, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Wästerlund, Iwan
    Effects of raw material particle size distribution on the characteristics of Scots pine sawdust fuel pellets2008In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 89, no 12, p. 1324-1329Article in journal (Refereed)
    Abstract [en]

    In order to study the influence of raw material particle size distribution on the pelletizing process and the physical and thermomechanical characteristics of typical fuel pellets, saw dust of Scots pine was used as raw material for producing pellets in a semi industrial scaled mill (similar to 300 kg h(-1)). The raw materials were screened to a narrow particle size distribution and mixed into four different batches and then pelletized under controlled conditions. Physical pellet characteristics like compression strength, densities, moisture content, moisture absorption and abrasion resistance were determined. In addition, the thermochemical characteristics, i.e. drying and initial pyrolysis, flaming pyrolysis, char combustion and char yield were determined at different experimental conditions by using a laboratory-scaled furnace. The results indicate that the particle size distribution had some effect on current consumption and compression strength but no evident effect on single pellet and bulk density, moisture content, moisture absorption during storage and abrasion resistance. Differences in average total conversion time determined for pellet batches tested under the same combustion conditions was less than 5% and not significant. The results are of practical importance suggesting that grinding of saw dust particle sizes below 8 mm is probably needless when producing softwood pellets. Thus it seem that less energy could be used if only over sized particles are grinded before pelletizing.

  • 194.
    Bergvall, Michael
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utformning av databasdriven webbapplikation i ASP.NET C# och Microsoft SQL Server2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 195.
    Bergvik, David
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Designing experiences for virtual reality, in virtual reality: A design process evaluation2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Creating immersive experiences for virtual reality (VR) presents new design opportunities and challenges that do not appear when creating experiences on a screen. Creating prototypes and exploring concepts in VR is today limited to professionals with previous knowledge in 3D application development, and testing 3D experiences requires the usage of an Head-Mounted Display (HMD), which forces professionals to switch medium from the computer to an HMD. With new advances in this field, there have to be new solutions to these challenges. The goal of this thesis is to explore how VR technology can be utilized in the experience design process for VR. This is achieved through a literature study and conducting expert interviews, followed by a hardware evaluation of different HMDs and concept creation using rapid prototyping. From the interviews, a number of issues could be identified that correlates with the research from the literature study. Based on these findings, two phases were identified as suitable for further improvements; Concept prototyping and testing/tweaking of a created experience. Lo-fi and hi-fi prototypes of a virtual design tool were developed for HTC Vive and Google Daydream, which were selected based on the hardware evaluation. The prototypes are designed and developed, then tested using a Wizard of Oz approach. The purpose of the prototypes is to solve some of the issues when designing immersive experiences for HMDs in the suitable experience design phases that were identified by analyzing the interview results. An interactive testing suite for HTC Vive was developed for testing and evaluation of the final prototype, to verify the validity of the concept. Using Virtual Reality as a medium for designing virtual experiences is a promising way of solving current issues within this technological field that are identified in this thesis. Tools for object creation and manipulation will aid professionals when exploring new concepts as well as editing and testing existing immersive experiences. Furthermore, using a Wizard of Oz approach to test VR prototypes significantly improves the prototype quality without compromising the user experience in this medium. 

  • 196.
    Bergwaahl, Johannes
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Orsaker till differens mellan beräknad och uppmätt energianvändning för flerbostadshus2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The European parliament has, during recent years, continuously updated their energy efficient requirements and directives underlining how much energy a building may use. Since the building sector accounts for such a large amount of the total energy use in Sweden, it’s important to make it more efficient.

    During a building’s planning phase, the energy use must be calculated in order to see whether the building will meet the building codes set by the Swedish National Board of Housing, Building and Planning. Unfortunately, it is very common that the actual use differs from the calculated, because of uncertainties in the input data.

    In this master thesis, input data that is used in energy calculations for apartment buildings has been studied. This has been performed thoroughly through a literature study and via computer simulations in which an apartment building is simulated using IDA ICE. Lastly, a sensitivity analysis was performed where the effect from variations in the input data was compiled.

    The results show that variations in hot-water use, indoor temperature and hot-water circulation losses also assumptions about thermal bridges and buildings mechanical systems can have significant impact on a building’s energy use. For new smaller apartment buildings the energy loss from hot-water circulation can amount to much higher than what is recommended as input data. Therefore, it is important to use as little standardized input data as possible to reduce the uncertainties.

  • 197.
    Bertheim, Jane
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Designing Digital Nudges to Encourage Sustainable Decisions: Developing and Testing a Framework2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The awareness of environmental impacts lead to that organizations are starting to work towards UN's global sustainability goals. To influence customers into a more sustainable behaviour, organizations have the potential to look at nudging as a tool. A nudge is a way to alter peoples behaviour into taking a certain decision. However, since many organizations offer their service or product in the digital environment, such as websites or apps, increased knowledge of digital nudging is required. This thesis aims to establish a framework for how nudges should be designed and used on digital platforms to encourage sustainable decisions. The purpose is to enlighten designers of digital environment of the potential of nudges, pitfalls to avoid, and a general design process to follow. The framework is based on a literature study and interviews with people familiar with the concept of nudging. To examine how the framework works a case study is performed, this includes a workshop, performing a user research, developing prototypes and finally, conduct user tests. By testing the framework further methods could be found, this meant that more practical steps could be included in the framework. The result of this thesis shows that the framework proved to be useful and functional to use when designing digital nudges to encourage sustainable decisions.

  • 198.
    Beyer, Klas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Radon och grundläggningsmetoder: Att utforma allmänna föreskrifter2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Radon is a radioactive gas that occurs everywhere in the ground. Radongas canenter buildings through domestic water and building materials, but the main re-ason for high radon levels in the indoor air is ground radon entering through theconcrete slab. The decay product of Radon (radon daughters) can attach to dustand other matter that we inhale. It then decomposes in our lungs and emits alfaradiation that can damage DNA cells and lead to lung cancer. It is therefore im-portant to design the slab in a way that prevents radon from entering the building.When planning a building, the building planner adds general regulations on thedrawings, a kind of advice and instructions that should be followed by involved con-struction partners. On Sweco’s internal network, there is an aid that will help thebuilding planner to set up general regulations. With a few quick clicks the buildingplanner can develop general regulations for thermal insulation or geo-investigation,etc. Today however, there are no general regulations regarding radon on Swecosinternal network. This work aims at establishing valid regulations for planningconcrete slabs with consideration to radon.The focus on this project has primarily been about creating a broad knowledge ofthe subject and then identify the most essential factors to include when the generalregulations are to be formulated. There is no general way to design a slab leakageof radon gas because one has to adapt radon solutions to each specific project. Itis very difficult to design general regulations since there are no general solutions.The result of this project is two regulations. One solution for designing a slab onsoil with normal levels of radon and another one for slabs on soil with high levelsof radon.Proposed regulation for foundation on normal radon soil.The entrepreneur is responsible for ensuring that appropriate radon preventionmeasures are taken to the extent that the limit value 200 Bq/m3is not exceeded.Cut-outs and possible imperfections are sealed with alkali-resistant elastic joint orequivalent.Proposed regulations for foundation on high radon soil.The entrepreneur is responsible for making the foundation air and diffusion resi-stant to the extent that the limit value 200 Bq/m3is not exceeded. Cut-outs andpossible imperfections are sealed with alkali-resistant elastic joint or equivalent.

  • 199.
    Billmark, André
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Delreparationer av våtrum ur ett hållbart perspektiv2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Varje år anmäls det uppskattningsvis 80 000 vattenskador i fastigheter till en kostnad på nära fem miljarder kronor för de svenska försäkringbolagen. Folksam som är ett av de största försäkringsbolagen i Sverige står för cirka 26 % av de svenska villaförsäkringarna och beställer byggreparationer för uppskattningsvis 800 miljoner kronor årligen till dessa fastigheter. Som beställare av arbeten på 800 miljoner kronor finns det möjligheter att ställa krav på byggbranschen, vilket även görs.Det är inte bara Folksam som ställer krav, försäkringsbolagen sammarbetar ofta för att hjälpa till att effektivisera byggbranschen. I nuläget fokuserar försäkringsbolagen på hållbarhet, de sammarbetar med olika branschorganisationer för att möjliggöra delreparationer i våtutrymmen. Detta är något som tidigare inte varit möjligt då det inte funnits anvisningar till hur detta ska genomgöras och materialtillverkare har inte haft monteringsanvisningar för detta, delreparationer kan därför inte utföras på ett fack-mannamässigt sätt. Då det inte utförs fackmannamässigt följs inte de branschregler som idag finns i Sverige, behöriga företag utför enbart arbeten som följer branschreglerna de är certifierade inom. Exempel kan de vara certifierade inom Byggkeramikrådets branschregeler eller Säkra våtrumAv de 800 miljoner kronor som Folksam betalar ut i byggskador finns det ett mörkertal på en kostnad av skador som egentligen inte ska ersättas. Genom att öka försäkringstagares kunskaper angående fördelarna med delreparationer ska mörkertalet minskas. Det är inte bara utgifterna på 800 miljoner som kan minskas utan även en minskning av den negativa miljöbelastningen och den ohälsa som finns hos fastighetsbrukare. Uppskattningsvis kan upp till 90 % av materialet i ett våtrum sparas genom att utföra en delreparation. Utförandetiden och kostnaden av delreparationer kan minska till 1/5 genom att undvika heltäckande reparationer. Minskad utförandetid minskar perioden som de boende inte kan bruka våtrummet. Skadan åtgärdas i ett tidigt skede vilket bidrar till att motverka de boendes ohälsa som kan uppstå till följd av mögel eller liknande.Fastighetsägaren kan ta till sig denna information och se värdet i att kunna utföra delreparationer och samtidigt bidra till en hållbar utveckling.Genom djupgående studier ska information som ökar fastigetsägarnas vetskap om de framtida möjligheterna med delreparationer, samt för- och nackdelar med dessa metoder.

  • 200.
    Biswas, Amit
    et al.
    Luleå Tekniska Universitet.
    Rudolfsson, Magnus
    Sveriges Lantbruksuniversitet.
    Broström, Markus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Umeki, Kentaro
    Luleå Tekniska Universitet.
    Effect of pelletizing conditions on combustion behaviour of single wood pellet2014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 119, no 15, p. 79-84Article in journal (Refereed)
    Abstract [en]

    This paper presents how pelletizing die temperature and moisture content affect combustion behaviour of single wood pellet. Pine wood particles with two different moisture contents (i.e. 1 wt.% and 12 wt.%) were pelletized in a laboratory-scale single pelletizer (single die pellets) at die temperature of 20, 100, 150 and 200 °C. The pellets were combusted in a laboratory scale furnace at 800 °C. Time required for single pellet combustion generally increased with both increase of pelletizing temperature and moisture content of biomass. In addition, combustion behaviour of single die pellets was significantly different than those produced in a pilot scale pelletizing plant (semi-industrial scale pellet). That difference was due to variation in physical properties of pellets (e.g. density, and morphology).

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