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  • 51.
    Allard, Ingrid
    et al.
    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.
    Östin, Ronny
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    A methodology to investigate the building energy performance gap2015In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118Article in journal (Other academic)
    Abstract [en]

    In order to evaluate compliance with requirements on building energy performance, it is necessary to find strategies to process discrepancies from the results of forward simulations in the design stage and of measurements in the operated stage. The gap between designed performance and measured performance is referred to as the “performance gap”. It can be divided into a procurement gap (between intended design and verified performance) and an operational gap (between verified performance and non-normalized measurements).  

    In this work we introduced a methodology for performance gap analysis, based on separating the procurement- and operational gap. An important component to do this is calibrations of calculations using measured data. The suggested methodology allows for more detailed verifications of building energy performance and can be used to study how indicators reflect the performance gap. The proposed methodology is tested using data from a well-documented and measured operated single family building, in sub-arctic climate in Sweden.

    The indicators studied in the verification were carefully analyzed. The methodology was found reliable based on the obtained results and a sensitivity analysis. An overall observation is that the applicability of the methodology depends on the accuracy of the hybrid method. The accuracy of the performance gap analysis per definition depends on the available information of the operated building, and consequently to access to extensive measured data.

  • 52.
    Almgren, Mattias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Effekten av dagsljus- och närvarostyrd LED-belysning i en befintlig kontorsbyggnad ur energi-, ekonomi- och ljusmiljösynpunkt2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An important measure to reduce buildings’ environmental impact is to make the artificial lighting more effective, which is the biggest electricity consumer of Swedish office buildings and accounts for more than 30 % of the total electricity consumption.A case study has been carried out in this master thesis as a part in an existing project with ÅF Lighting, where new strategic avenues has been explored in which to combine day- and electrical light in office landscapes in a smarter, more energy-efficient manner and at the same time improve the lighting environment.Two office spaces at the own head office of ÅF in Solna, Stockholm has been used in the case study, where two different LED lighting solutions got installed. One with pendant luminaries, desk lamps and downlights, and one with only recessed luminaires.Through several computer simulations, electricity and light measurements, questionnaires, interviews etc., it has been investigated how the heat and cooling load, electricity consumption, lighting quality and operating costs has been affected of the change of the lighting system. The lighting environment, daylight conditions, heat and cooling load, economical savings and electricity consumption for the two offices has been investigated in diaLUX, DIVA-for-Rhino, IDA ICE 4.7, ecoCALC and Mitec Monitor, respectively. The electricity measurements showed that the lighting solutions’ electricity consumption got reduced with 71,6 % on floor 5 and 68,1 % on floor 10 with the new LED lighting solutions and control systems during the investigated month.Through the IDA ICE energy simulations over a year it was shown that the total yearly cooling load to floor 5 and floor 10 got reduced with 19 % and 17 %, which can be explained by the lesser heat gain from the more energy efficient lighting and the controlling of this. Though a small increase in heating load, the total energy consumption got reduced with around 12-14 % on both floors. The simulations also showed that the total electricity consumption of the lighting got reduced with 70 % for floor 5 and 63 % for floor 10 after the change to the new LED lighting solutions and implementation of control systems.The LCC for the new lighting solutions showed that these have a higher investment cost than the total operation cost for the existing solution over the life cycle. However, the costs to run the LED solutions are less than a third of the operation costs for the existing solution, and after the exchange the carbon dioxide emissions can be reduced with close to 70 %.Through this case study it has been shown that the energy consumption from lighting can be highly reduced with the installation of energy efficient lighting in combination with smart control systems, and it can also have a positive effect on the lighting environment. However, the high investment costs of the LED solutions lead to the conclusion that installation of these solutions today is not economically justifiable.

  • 53.
    Almqvist, Jonna
    et al.
    SP Processum.
    Westin, Gunnar
    SP Processum.
    Öberg, Christian
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Skoglund, Nils
    Luleå University of Technology, Department of Department of Engineering Sciences and Mathematics, Energy Science.
    Samförbränning av bioslam från massaindustrin i bubblande fluidiserad bädd2016Report (Other (popular science, discussion, etc.))
  • 54.
    Almstedt, Kalle
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektiviseringsåtgärder på Gustavsvik resorts AB2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Badhus är den typ av svenska lokaler som använder mest energi, ofta med en energiprestanda som är långt högre än BBRs gränsvärden för ny- och ombyggnationer. Denna rapport är resultatet av ett examensarbete för Civilingenjörsprogrammet i energiteknik vid Umeå Universitet. Det har utförts på uppdrag av teknikkonsultföretaget KAMTechnology AB åt upplevelseanläggningen Gustavsvik resorts AB. Gustavsvik ligger i Örebro och består av bland annat äventyrsbad, motionsbad, gym, camping med mera. Detta examensarbete syftar till att utreda möjligheter och ta fram förslag till energieffektiviseringsåtgärder för Gustavsviks badanläggning. Studien har avgränsats till att behandla energisystemet för kyla och värme med fokus på kylkretsen och värmeåtervinning ur gråvatten.

    Potentialen för värmeåtervinningen ur Gustavsviks gråvatten har beräknats till cirka 130 000 kWh/år, vilket utgör ca 20 % av deras köpta energi för varmvattenberedning. Det finns en handfull produkter på marknaden för värmeåtervinning ur grå- och avloppsvatten, som hävdar god prestanda och lönsamma installationer. Det kan konstateras att det finns få utförda studier och genomförda projekt som presenterar mätvärden och prestanda för dessa typer av installationer. Intresset för dessa typer av anläggningar tycks ändå öka och branschorganisationer försöker skynda på utvecklingen genom bland annat tekniktävlingar vilket sammanfattas i, och styrks, av litteraturstudien som utgör en del av denna rapport.

    Platsbesök har utförts för att samla in data från anläggningens styr- och övervakningssystem. Insamlad data har loggats under 2013 och utgörs av temperaturer, flöden samt el- och fjärrvärmeanvändning. Kompletterande mätningar av kyl- och värmebärarens flöde utfördes även för att kunna uppskatta värmepumparnas kyl- och värmeproduktion En begränsad kartläggning av Gustavsviks kylkrets har utförts, där även anläggningens två värmepumpar har utvärderats. Värmepumparnas prestanda visade sig vara sämre än vad tillverkarna uppger och det finns därmed en möjlig besparingspotential i att förbättra och optimera deras drift. Datahanteringen och beräkningar har främst gjort i Microsoft Excel. Under examensarbetet har det identifierats flera fall där man kyler och värmer på samma ställe, vilket betraktas som möjligheter till energieffektiviseringsåtgärder. Slutsatserna av denna studie är att Gustavsvik har stora möjligheter till att sänka sin energiförbrukning. Detta genom att bland annat installera värmeåtervinning ur gråvatten, bygga bort konkurrerande värme och kyla samt att justera in sitt energisystem. Det som Gustavsvik rekommenderas att göra i första hand är en heltäckande energikartläggning av sitt energisystem. 

  • 55.
    Al-Naser, Mohammad
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Söderström, Ulrik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Reconstruction of occluded facial images using asymmetrical Principal Component Analysis2012In: Integrated Computer-Aided Engineering, ISSN 1069-2509, E-ISSN 1875-8835, Vol. 19, no 3, p. 273-283Article in journal (Refereed)
    Abstract [en]

    When only non-occluded image parts are available for facial images it is difficult or impossible to correctly recognize the person in the image. The problem addressed in this work is reconstruction of the occluded parts in facial images; e. g. eyes covered with sunglasses. Asymmetrical Principal Component Analysis (aPCA) allows estimation of occluded facial parts based on the content of the facial parts which are visible. aPCA is used to estimate full non-occluded faces from 3 kinds of occlusion with 2 different reconstruction methods in this work and we present the results with both objective and subjective evaluation. The subjective evaluation shows that clear and sharp image regions are preferred even if this results in visible edges in the images. The method also performs well when a different facial expression than the one in the database is used to calculate the reconstruction parameters.

  • 56.
    Al-Naser, Mohammad
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Söderström, Ulrik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Reconstruction of occluded facial images using asymmetrical principal component analysis2011In: 2011 18th International Conference on Systems, Signals and Image Processing (IWSSIP), IEEE , 2011, p. 276-279Conference paper (Refereed)
    Abstract [en]

    When face images are occluded it becomes difficult or impossible to make a correct recognition based on only the non-occluded parts. With asymmetrical Principal Component Analysis (aPCA) it is possible to estimate occluded regions based on the content of the non-occluded pixels. Entire faces can be reconstructed from images where some parts are occluded with the occluded region being estimated based on the relation to the non-occluded region. We show the result with 3 different occlusion cases and compare two reconstruction methods. The results are measured both objectively and subjectively and it is shown that a clear and sharp image part should be used even if the resulting image have edges in it.

  • 57.
    Alrifaiy, Ahmed
    et al.
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Luleå University of Technology.
    Bitaraf, Nazanin
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Luleå University of Technology.
    Druzin, Michael
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology.
    Lindahl, Olof
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Luleå University of Technology.
    Ramser, K
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Luleå University of Technology.
    Hypoxia on a chip: a novel approach for patch-clamp studies in a microfluidic system with full oxygen control2013In: World Congress on Medical Physics and Biomedical Engineering May 26-31, 2012, Beijing, China / [ed] Mian Long, Springer Berlin/Heidelberg, 2013, p. 313-316Conference paper (Refereed)
    Abstract [en]

    A new approach to perform patch-clamp experiments on living cells under controlled anoxic and normoxic conditions was developed and tested. To provide an optimal control over the oxygen content and the biochemical environment a patch-clamp recording micropipette was integrated within an oxygen tight poly-methyl methacrylate (PMMA) based microchip. The oxygen content within the microfluidic chamber surrounding patch-clamp micropipette was maintained at 0.5-1.5 % by a continuous flow of artificial extracellular solution purged with nitrogen. The nerve and glial cells acutely obtained from the male rat brain were trapped by the optical tweezers and steered towards the patch-clamp micropipette through the channels of the microchip in order to achieve a close contact between the pipette and the cellular membrane. The patch-clamp recordings revealed that optical tweezers did not affect the electrophysiological properties of the tested cells suggesting that optical trapping is a safe and non-traumatizing method to manipulate living cells in the microfluidic system. Thus, our approach of combining optical tweezers and a gas-tight microfluidic chamber may be applied in various electrophysiological investigations of single cells were optimal control of the experimental conditions and the sample in a closed environment are necessary.

  • 58. Alrifaiy, Ahmed
    et al.
    Lindahl, Olof A
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics. Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Ramser, Kerstin
    Polymer-based microfluidic devices for pharmacy, biology and tissue engineering2012In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 4, no 3, p. 1349-1398Article, review/survey (Refereed)
    Abstract [en]

    This paper reviews microfluidic technologies with emphasis on applications in the fields of pharmacy, biology, and tissue engineering. Design and fabrication of microfluidic systems are discussed with respect to specific biological concerns, such as biocompatibility and cell viability. Recent applications and developments on genetic analysis, cell culture, cell manipulation, biosensors, pathogen detection systems, diagnostic devices, high-throughput screening and biomaterial synthesis for tissue engineering are presented. The pros and cons of materials like polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polystyrene (PS), polycarbonate (PC), cyclic olefin copolymer (COC), glass, and silicon are discussed in terms of biocompatibility and fabrication aspects. Microfluidic devices are widely used in life sciences. Here, commercialization and research trends of microfluidics as new, easy to use, and cost-effective measurement tools at the cell/tissue level are critically reviewed.

  • 59.
    Alvros, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Prototyptillverkning av innebandymaskin: Maskin för repetitionsträning för innebandymålvakter2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Many sports today have started adopting technical appliances to make practice easier, it can be anything from machines firing goal shots to simple computer programs that help keep track of statistics and what to practice. One sport which is slightly lacking appliances like this is floorball. Because of this, two students at Umeå University built a prototype of a machine specialized for practicing floorball as their thesis work.

    The requirements for the machine were that it had to be able to shoot balls with different speeds, different angles, and different elevation angles to be able to simulate different kind of floor ball scenarios. It would also have other technical solutions to further help during practice, such as an automatic feed of balls.

    The machine was built out of materials such as steel, plexiglass, and plastics. And certain mechanical and electrical components were used such as ball bearings, axial bearings, diverse circuits, and motors. The different materials were then welded and bolted together, and doublesided tape was used to temporarily hold certain parts together.

    The result was a machine that works, and meets most of the requirements.

    Despite the satisfactory results some of the machines functions never worked fully as intended or were scraped, much room were therefore left for future improvements. This was mostly because of lack of time and prior knowledge, and the results could have been improved through better planning and more time.

  • 60.
    Ambertsson, Birger
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Stabilisering av lätta trähus2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Med Tommy Persson kvalitets- och produktchef vid Masonite Beams AB i Rundvik diskuterades problemet kring infästning av väggelement med hög färdighetsgrad till grunden. Det bestämdes att arbetet skulle fokusera på en- och tvåbostadshus och att endast fenomenet stjälpning skulle beaktas.

    Lastfördelningen gjordes enligt vad Klas Nyman skrivit i sitt examensarbete Tredimensionella effekter vid horisontalstabilisering av volymbyggda trähus. Beräkningar av lyftkraft gjordes enligt den plastiska metoden med syllen förankrad mot lyft medan frontregeln inte är förankrad mot lyftning som Bo Källsner och Ulf Arne Girhammar beskriver i sin bok Horisontalstabilisering av träregelstommar. För beräkning av skruvars bärförmåga tillämpades Eurokod 5. För beräkning av 5-percentilsvärden från provning tillämpades SS-EN 14358:2006 Träkonstruktioner.

    Resultat; de två studerade fästmetodernas dimensionerande bärförmåga är 1.61 kN och 1,23 kN, lyftkraften i syllen är i storleksordningen 3-19 kN/m.

    Rapporten kan ses som en fingervisning på hur stora lyftkrafter som uppstår i syllen när det blåser och ett alternativ på hur man ska beräkna dessa lyftkrafter. Med mer tid skulle en bättre infästning av väggelement till grunden kunna utformas.

  • 61.
    Amkoff, Leon
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utveckling av simuleringsmodell och automatiserad nedställningsfunktion för en frontlastare2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A growing global population and large demands for crops worldwide is driving agricultural technological advances forward. In developing new automatic control functions for front end loader applications, Ålö AB needed a reliable and effective plant model of their front end loader Quicke Q5M. The plant model should include the associated mechanical and hydraulic system and be capable of rendering simulation and 3D animation in real time. An automated put down control function would also be of benefit for farming operators, speeding up the commonly performed farming task of putting down material from an elevated position. A plant model for the Quicke Q5M with a Load Sensing hydraulic system was developed in MATLAB Simulink with Simscape Multibody and Simscape Fluids. The performance of the simulated plant model was evaluated. The plant model showed some consistent results when compared to sensor data logs from a real-world front end loader. An automatic put down control function for material was also developed and tested in Simulink. A collision detection algorithm was constructed by analyzing sensor data logs from a real-world tractor putting down material on the ground. Velocity and acceleration estimations were made from angular position and pressure sensors to detect the contact between material and ground. The control function automatically stopped the lowering movement when contact was detected. The performance and accuracy of the control system under different scenarios were analyzed and discussed. Although the simulations of the plant model and proposed control function seemed realistic, the consistency of the plant model was hard to quantify since there was no time left for any thourough physical tests. It is recommended that future development of both the plant model and control system begin with an implementation test of the control system in a real-world tractor. This would help determine how accurately the plant model represents the front end loader. It would also allow evaluation and further tuning of the control function in a real physical environment.

  • 62.
    Anani, Adi
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    M-learning in review: Technology, standard and evaluation2008In: Journal of Communication and Computer, ISSN 1548-7709, Vol. 5, no 11, p. 1-6Article in journal (Refereed)
    Abstract [en]

    Nowadays E-learning as a form of learning depending on networks and computer devices has been expanding by leaps and bounds. As a special kind of E-learning, M-learning (mobile learning) aims at the use of mobile devices anywhere at anytime by anybody. In this paper, the technologies to develop a M-learning system is deeply analyzed according to the layer model at first. Secondly, from the view of application, the standardization in M-learning is researched in order to accelerate the development and popularization of M-learning. Finally, quality estimation of M-learning system is discussed from the view of QoE (quality of experiences). The experience form end-user is the sole effective norm to judge the result of M-learning technology. It is no doubt that technologies, standardization and evaluation will play very important parts in the course of M-learning development.

  • 63.
    Anani, Adi
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Li, Haibo
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Diagnostic instrument for children with reading disorders2006In: International Journal of Scientific Research, ISSN 1021-0806, Vol. 16, p. 167-170Article in journal (Refereed)
    Abstract [en]

    A simple and cost-effective wearable gaze tracking system is designed to observe the readingpattern of patients with reading disorders in order to facilitate for the work of ophthalmologists andthe multidisciplinary treating teams in making reliable diagnosis. The system constitutes of twominiaturized cameras mounted on a headset; one for eye tracking and one for the scene. The eyetracking information is combined with information extracted from the picture of the forwardlooking camera to online identify the gaze point. When reading a text the gaze point moves and areading pattern is created.

  • 64.
    Anani, Adi
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Zhang, Deng-yin
    Institute of Signal Processing and Transmission, Nanjing University of Posts and Telecommunications, China.
    Li, Haibo
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    QoS-guaranteed packet scheduling in wireless networks2009In: Journal of China Universities of Posts and Telecommunications, ISSN 1005-8885, Vol. 16, no 2, p. 63-67Article in journal (Refereed)
    Abstract [en]

    To guarantee the quality of service (QoS) of a wireless network, a new packet scheduling algorithm using cross-layer design technique is proposed in this article. First, the demand of packet scheduling for multimedia transmission in wireless networks and the deficiency of the existing packet scheduling algorithms are analyzed. Then the model of the QoS-guaranteed packet scheduling (QPS) algorithm of high speed downlink packet access (HSDPA) and the cost function of packet transmission are designed. The calculation method of packet delay time for wireless channels is expounded in detail, and complete steps to realize the QPS algorithm are also given. The simulation results show that the QPS algorithm that provides the scheduling sequence of packets with calculated values can effectively improve the performance of delay and throughput.

  • 65.
    Anani, Sani
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Hand Reader – A hand Geometry Based Personal Verification System2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report presents my bachelor thesis performed at the Department of Applied Physics and Electronics at UmeåUniversity. The Digital Media Lab was the assigner, supervising and assisting me during the project.

     

    A simple and smart system to verify a person’s identity using hand geometry as a biometrical identity is developed. The system should tolerate some deviation in hand placement and will not use pins or pegs. A complete system, hardware and software, is delivered. A webcam based hand-scanner is constructed and designed to operate on a PC utilizing Matlab for image processing.

  • 66.
    Anderholdt Helgesson, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analys och kalibrering av flödesmätare i laboratoriemiljö2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    STT Emtec AB is a technically focused company with an internal combustion engine laboratory in Njurunda a few kilometers south of Sundsvall. I this laboratory, development of purification systems for exhaust gases and calibration and testing of internal combustion engines is carried out. In this type of activity, it is important to measure the air flow going into the engines in a reliable way, which is a reoccurring problem today. The system used today consists of a variety of commercial flow meters from the automotive industry.This project aims to analyze and improve the existing measurement system to achieve higher accuracy and robustness, while making the system less dependent on installation. The development of a calibration device to calibrate the flow measuring devices on the site was also one part of the project.The things learned by a literature study were used to build a flow simulation setup to be used to evaluate three different measuring techniques (Debimo blades, Denso ultra-sonic flow meter and Bosch hot film anemometer). Influence from varied placing of the measuring devices and flow profiles were investigated, with focus on accuracy and robustness.The results show that different flow profiles disturbs the performance of flow meters with only one point of measurement, even with a straight pipe section, prior to the meter with a length ten times that of the hydraulic diameter. The use of only a flow conditioner (a method for conditioning the flow prior to the measuring device) magnifies the flow profile. A combination of flow conditioners and other flow conditioning devices, such as nets, is necessary to reduce the flow profile bias.A combination of three Denso ultrasonic flow meters in the same cross sectional area, didn’t give any improvement of the measurement. The signal from these three sensors didn’t give a correct value for the mean flow velocity and thus, the solution was discarded.The construction of the calibration device was halted due to the bad performance of the intended compressor; instead a small radial fan was installed, but was deemed too small for the setup. For future development though, these results can be used as a starting point.As a result of the study, it can be concluded that the Debimo blades were the ones most suited for the task after the evaluation of the different flow meters, although the disadvantage of these is the poor performance under 5 m/s. Thus, by a combination of the Debimo blades and the existing Denso flow meters, a more robust measuring system can be constructed.In the future it is advisable to look at different flow meters, as a complement to the Debimo blades or use them as an enhancing action together with the Denso flow meters. Also, if the future offers another economic situation, industrial measuring systems can be favorable for solving some of the problems in the current measuring system.

  • 67. Anderssen, C.
    et al.
    Lindgren, R.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Carvalho, R.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Malmborg, V.
    Ahlberg, E.
    García-López, N.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Eriksson, A.
    Kristensen, T.B.
    Svenningsson, B.
    Boman, C.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Pagels, J.
    SOA Formation and Particle Characteristics in the Emissions from Biomass Cook Stoves Used in the Developing Countries2017In: SOA Formation and Particle Characteristics in the Emissions from Biomass Cook Stoves Used in the Developing Countries, 2017Conference paper (Refereed)
  • 68. Andersson, Alina
    et al.
    Robertsson, Anders
    Shiriaev, Anton S.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Norwegian Univ Sci & Technol, Dept Engn Cybernet, Trondheim, Norway.
    Freidovich, Leonid B.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Johansson, Rolf
    Robustness of the Moore-Greitzer Compressor Model's Surge Subsystem with New Dynamic Output Feedback Controllers2014In: IFAC PAPERSONLINE, Elsevier, 2014, Vol. 47, no 3, p. 3690-3695Conference paper (Refereed)
    Abstract [en]

    This work presents an extension of a design procedure for dynamic output feedback design for systems with nonlinearities satisfying quadratic constraints. In this work we used an axial gas compressor model described by the 3-state Moore-Greitzer compressor model (MG) that has some challenges for output feedback control design (Planovsky and Nikolaev 1990), (Rubanova 2013). The more general constraints for the investigation of the robustness with respect to parametric uncertainties and measurement noise are shown.

  • 69.
    Andersson, Björn
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energiinventering av Universumhusets elanvändning2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete utfördes på uppdrag av Akademiska Hus AB i Umeå under våren 2017. I det här arbetet utfördes en energiinventering av elanvändningen i Universumhuset på Campus i Umeå. Akademiska Hus planerar en större ombyggnation av Universumhuset. Mindre renoveringar och ombyggnationer har genomförts under åren, men vissa system och konstruktioner är från byggåret 1970. Idag finns ett flertal olika hyresgäster och verksamheter inom byggnaden.

    I det här arbetet gjordes en inventering och fördelning av byggnadens årliga elanvändning. Fördelningen av elanvändningen beräknades dels efter objektskategorier men även för användningen av fastighets- och hyresgästel. Syftet med detta var att skapa ett underlag för energibesparande och energieffektiviserande åtgärder inför planerad ombyggnad. Utöver detta gjordes även analyser av byggnadens effektnivåer och utredningar för möjlighet till behovsstyrning av anläggningen.

    Utifrån inventering konstateras att byggnadens totala elanvändning är ca 1200 MWh/år, var av fastighetsel står för 53 % och hyresgästel för 46 %. Resultat för beräknad fördelning av byggnadens totala elanvändning visar att storköksutrustning står för den enskilt högsta elanvändningen på 23 % följd av belysning 19 %, värmepump 16 % och fläktar 13 %.

    Den årliga energianvändningen beror på utrustningens effekt och driftstid och fick i många fall antas. Elanvändnigen beror på flera olika anledningar och varierar under året. Stora delar av utrustningen är även behovsstyrd vilket ger stora variationer och ger en viss osäkerhet i den beräknade fördelningen.

    För en effektivare elanvändning föreslås generellt en utökad behovsstyrning för styrning av byggnadens system. Universumhuset har idag en stor del äldre utrustning vilket föreslås bytas ut mot modern utrustning med ny teknik. Även förändring av beteendet för användningen av utrustningen rekommenderas, vilket skulle kunna resultera i en betydlig energibesparing.

  • 70.
    Andersson, Britt
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Svängande sensorer hittar prostatacancer2010In: medtechinfo.comArticle in journal (Other (popular science, discussion, etc.))
  • 71.
    Andersson, Britt M.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Sundqvist, Bertil
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Thermal diffusivity and thermal conductivity of YBa2Cu3O7-d and YBa2Cu4O8 between 20 and 300 K1992In: Proceedings of the Joint Nordic Spring Meeting '92 / [ed] Per-Anker Lindgård, Roskilde: Risö National Laboratory/Grafisk Service, Risö , 1992, p. 251-Conference paper (Other academic)
  • 72.
    Andersson, Christer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Verifiering av objektsbaserade 3D-modeller.: En fallstudie av arkitektmodell upprättat av Link Arkitektur med avseende på kvalitetssäkring i Solibri Model Checker inför import i IDA ICE.2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Export and import of BIM-models via IFC has in some cases shown to be problematic regarding ability to carry nessicary information such as for exampel geometry between different application. Good IFC-models is said to be the answer when it comes to creating a good informationflow in the construcion-sector, but seems to fail alot of the times today. This problem can be deived to lack of knowlege how IFC-models needs to be created in order to fulfill a specific purpose. This report preforms a quality controll of a existing IFC-model created at Link Architecture in Umeå, in order to be importabel in IDA ICE, and gives a detailed describtion of how its done. The control is done using Solibri Model Checker and the resaults of the test shows that there are some major innacuracies in the model that makes it not importable in IDA ICE. This report establish the fact that it might be important to preform continius controls of througout a BIM-project in order to avoid misstakes during the modelling-process.

  • 73.
    Andersson, Cristian
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Förundersökning: Uppförande av vindkraftverk på Åsberget, Hudiksvalls kommun2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Wind power expansion is often preceded with an extensive procedure where the technical, environmental and economic circumstances are investigated. Alongside of this there are also different permits that need to be granted before a wind farm can be built. This whole process takes several years and is both very costly and risky since projects often are discontinued before being a finished project.

    The aim of this thesis is to perform a preliminary investigation which examines the conditions for wind power expansion on Åsberget. The basis of this investigation has originated from a previously done initial assessment, made by a company that specializes in developing wind power projects. By using commonly used methods in the industry, the report tries to answer questions which are of great importance when developing wind power projects.

    Åsberget shows potential for wind power although there are some complications that may prevent an establishment. The municipality’s approach to wind power on Åsberget is unknown and thus a big question mark. Some of the buildings around Åsberget may also prove to be problematic as they have shown to have a high historical value.

    By relocating some of the wind power plants several of the presented problems can be minimized. If the project is continued suggestions for future work have been recommended.

  • 74.
    Andersson, Emelie
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Multiple Platform First: Design Guidelines for Multiple Platform Games2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis investigates the two gaming platforms PC and Console and how the interfaces of games on these platforms could be designed more efficiently making it easier to release games on multiple platforms. In other words, how could the Multiple Platform First method look. Little previous work exist on this problem so this thesis work gathers information from other industries and also research on user interfaces in games in general. By looking at games running on both platforms different best practises and common solutions were discovered. A study was conducted testing different in-game components on users. The components were selected to test if the users would accept non-traditional components since users detect when playing on an interface not intended for the platform. This makes the study very complicated since the "best" solution might not work if the users does not accept it for the intended platform. Concepts were designed to combine the testing of solutions with the users opinion of the solutions. The chosen concepts were researched both in literature and by looking at present implementations in games. To be able to user test the solutions they were iterated from low fidelity prototypes on paper to high fidelity prototypes that were playable in Unity. The prototypes were tested on users and data gathered through Think Aloud comments and questionnaire answers. This study presents a first draft of how a multiple platform approach can be achieved.

  • 75.
    Andersson, Erik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utvärdering av möjligheten att tillvarata energi ur processvatten: En undersökning gjort vid Olofsfors AB på uppdrag av UMIA AB.2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The company Olofsfors AB manufactures drive belts for forest machinery, known as ECO-Tracks, and abrasion-resistant steel and cutting edges for graders, excavators and tractors, known as Bruxite and SharqEdges. Manufacturing these products requires the steel to be heated and molded, then submerged in water and hardened. The water used in the hardening of steel is pumped to the process from pits below the floor and then pumped back to the pit after it’s been used. Since the temperature of this water rises after being used to harden the steel the temperature of the pumping pit needs to be adjusted to maintain its setpoint of 21°C. This is done by disposal of hot water from the pit to the river outside while new, cold water, from the river is pumped into the pit. The hot water that is being disposed of contains energy that has not at all been utilized, this has led to the purpose of this report which is to examine the possibility to utilize parts of the energy in the water.

     

    Two possible outlets for the energy at the plant has been selected as especially interesting: • Heating of ventilation supply air in two units with low thermal efficiency and relatively high airflows where the supply air temperature is to be increased from 9 °C to 15 °C. • Fan heaters installed with electric batteries of approximately 200 kW capacity, which heats the premises and serves as an air barrier at the intake ports for metal.

     

    Calculations of power available in one of the factory pump pits during the heating season from October to May and the power required for deposition areas were made. The result obtained is illustrated by means of duration charts from which required and available energy is deduced.

     

    The result of this:

    Pump pit                             887 MWh / October to May

    Ventilation                          642 MWh / year

    Fan heaters                         515 MWh / year

     

    A draft measure has been developed in which two heat pumps delivers hot water for heating of both the ventilation supply air and liquid batteries in air fan heaters. This measure proposal means a cost saving of approximately 390 000 SEK / year where pay-off time of the investment is approximately 5 years.

  • 76.
    Andersson, Glenn
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Kommunikation mellan under- och byggentreprenör2015Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [en]

    The study about communication between subcontractor and design-and-build contractor are accomplished at Östervångskolan in Lund. The purpose with this study is to get a better understanding about how the communication works between the contractors today, find out which interferences and misunderstandings that influence the communication and which ways of communication that is being used at the working establishment. The building and development meetings are also being observed and analyzed at the working establishment. To examine how the contractors at Östervångskolan considered the communication today the method of qualitative interviews will be accomplished. These interviews generated a result, which was analyzed. The conclusion of this study is that the communication works fine but there’s a lot of deficits to rectify. One of the deficits that appeared was that the meeting protocol could be improved. A solution to this was to introduce a white board where the sub-contractors can write suggestions or thoughts. These will be processed by the supervisor and brought up at the weekly meeting to get a better participation in meetings. In the category “slutsats” more actions that will minimize the deficits in communication are described.

  • 77.
    Andersson, Hanna
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Designing Digital Nudges for Sustainable Travel Decisions2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Tourism is an important force for sustainable development in many countries. It provides millions of jobs which, for some countries, entails an increased gross domestic product (GDP). Unfortunately, there are downsides of tourism as well, and work towards sustainable tourism is now a key feature of many travel organizations. To influence consumers into more sustainable behavior, organizations can use nudging as a tool. A nudge uses a specific psychological effect to guide individuals towards a predefined choice. Since many travel companies provide their products through digital environments, such as websites or apps, knowledge of digital nudging is mandatory. The aim of this study was to investigate how digital nudging could be used to encourage more sustainable decisions on a travel company website. How the digital nudges should be designed, and how digital nudging would be perceived by consumers were investigated. The use of existing guidelines for how to design digital nudges resulted in prototypes of a travel company's website including several digital nudges. The guidelines included four steps: define the goal, understand the users, design the nudge and test the nudge. The result showed several digital nudges that after some design improvements have the potential to influence consumers to make more sustainable decisions on a travel company's website. The result also showed that the majority of the consumers had a positive attitude towards digital nudging in this context, although this needs to be further evaluated. Further research is also recommended to assess which nudge that works best for a given choice situation.

  • 78.
    Andersson, Hans
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Gustafsson, Magnus
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Olsson, Roger
    Almqvist, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    The Regio- and Stereoselective Synthesis of trans-2,3-Dihydropyridine N-oxides and Piperidines2009In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 48, no 18, p. 3288-3291Article in journal (Refereed)
    Abstract [en]

    No Abstract

  • 79.
    Andersson, Jakob
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Umeå Energi.
    Energikartläggning av ”Kontoret” vid Dåvamyrans kraftvärmeverk: En energikartläggning utförd med IDA ICE för en modern kontorsbyggnad hos Umeå Energi2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The law on energy audits for large companies was adopted by the Swedish Parliament in 2014 and implies that companies that answer to the law are to present a representative picture of their energy consumption. In addition, suggestions for cost-effective measures are to be made, that will lead to reduced energy consumption and more efficient use of energy. This energy audit was made in accordance with directives and the Swedish Energy Agency’s recommendations. It was done for Umeå Energy’s office building at Dåvamyrans CHP, which is their largest CHP for district heating. The building was completed in 2007, and is connected to the powerplant Dåva 1 by a subsurface tunnel. Dåva 2 was completed in 2010 to meet the increased need for heating in Umeå, and to reduce the share of oil in Umeå Energy's fuel mix. It is a highly energy efficient and environmentally sound facility for the production of district heating.

      As an energy simulation program IDA ICE performs very well when it comes to estimating a building's actual energy consumption, this program will be used for the energy audit of the office. The energy audit separates itself to estimate the energy consumption in the building for heating, cooling, building electricity and business electricity and exclude the external consumptions for lighting and transports.

      Measurements were taken for a week for the buildings electricity consumption. The values were then used together with an inventory of the effects of lighting, electrical components and assumptions for electricity consumption for the office part, to appreciate the building's total needs of business electricity. Inventories of ventilation and temperature measurements were made to get the heating demand for the model. Personal Attendance was also estimated, to be able to simulate the cooling need for which measurements are not available. The model was corrected thoroughly to match the estimated electric consumption and the heat consumption that had been measured, and corrected on the basis of boundaries for the model.

      The results showed that the building has a total annual energy requirement of 157,5 [kWh/m2], 97 [kWh/m2] for district heating, 55,2 [kWh/m2] for electricity consumption and 5,1 [kWh/m2] for district cooling . The corrected simulation according to measurements and estimates was used to make an energy balance for district heating, and to simulate different improvement actions that was later analyzed for individual and simultaneous influence on each other.

      A conclusion was drawn that the measure which favors both district heating, district cooling and electricity consumption, is a combination of all limited measures including the replacement of LED lamps for certain areas, turning of the lights and shutting down computers after hours, as well as the reduction of the air handling units operating times and reducing the temperature with one degree for the entire building. These combined measures balance and affect each other positively, and can provide potential savings of between 27 000 and 37 000 [SEK] per year depending on varying energyprices district heating and electricity. 

      Other practical measures that should be done is conducting measurements for the hot water demand, cooling need and electricity consumption for the building, since they aren’t being conducted currently. An adjustment of the ventilation flows should also be made, this is because some diverging flows were detected during measurements. It should be examined how the activation of night cooling functions during the summer. If it would be activated during summer it would provide a reduced cooling requirement. 

     

    Keywords: Energy Audit, Energy Efficiency, District Heating, Electricity Consumption, IDA ICE, Umeå Energi 

  • 80.
    Andersson, Jenny
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Lean filsofi - fem steg till ordning och reda på arbetsplatsen: Del 2 av 22014Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    Part 1 of 2 " Lean philosophy- five steps to get the workplace in order”, Angelica Jonsson, 2014

     

    Part one deals with the theory of what Lean and 5S are.

    Lean is a long-term approach that involves a quest to become the best on the market by increasing employee engagement, eliminate waste and focus on the right things.

    5S is a method of order in a system. Businesses around the world are using these 5S which stands for sort , straighten, shine, standardize and sustain.

     

    Part 2 of 2 ” Lean philosophy – five steps to get the workplace in order”, Jenny Andersson, 2014

     

    Part 2 deals with the practical about 5S and a short summery about the company Wibax AB where the degree thesis took place.

    Wibax has a a project which involves using 5S in practice and create order in the in preparation lab and in the control room.

    By finding a solution to this mess reduces the time that was previously spent on searching equipment. Instead of search, the workers can do the real work.

  • 81.
    Andersson, Jimmy
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Framtagning av PLC-baserat styrsystem till sågrigg, avsedd för standardiserat test på sågskyddskläder2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sammanfattning

     

    Detta examensarbete är utfört på Svensk Maskinprovning AB´s  laboratorium i Umeå.

    SMP Svensk Maskinprovning agerar som oberoende tredjepart och är ackrediterade av Swedac. I egenskap av ackrediteringen tar SMP på sig uppdrag att genomföra och ta fram tester för att verifiera att produkter uppfyller och följer den säkerhetsstandard de är tillverkad efter.

    SMP arbetar bland annat med säkerhetsprovning av skyddskläder för användare av handhållna motorsågar och ser till att dessa uppfyller gällande krav för CE-märkning.

     

    I arbetet med test av sågskyddskläder används för närvarande en specialbyggd, standardiserad testrigg. På grund av 20 år i drift och ökande säkerhetsrisker ska en ny enhet monteras. SMP har ett behov att uppdatera den nya testriggen med ett styrsystem som förenklar dagens arbete och ökar säkerheten för användaren. Målet med projektet var att ta fram ett förslag och bygga upp ett styrskåp kring en PLC-enhet och automatisera delar av de arbete operatör utför idag.

     

    Metoderna som använts i uppbyggnaden kan delas in i tre delar. Del ett som innefattar intervjuer med användare av testrigg för att få ideér kring skåplayout och programfunktion. Del två är litteraturstudie inom ämnet automation samt styr och reglerteknik för att erhåll de teoretiska kunskaper som krävs. Del tre är montering av apparatskåp vilket även inkluderar programmering av PLC och testkörning.

     

    Produkten av projekt Sågrigg är ett styrskåp som uppfyller kravspecifikationen. Styrskåpet består av ett apparatskåp där dörren agerar operatörspanel. Infälld i dörren är en HMI (Human Machine Interface) som kan styra testriggens alla funktioner. Som tillägg går det att styra alla delmoment från vred och knappar på operatörspanelen utifall HMI-panelen går sönder.

     

    Projektet har trots uppfyllande av kravspecifikation vissa saker som bör förbättras eller slutföras innan systemet kan anses som färdigt. Vissa önskemål angående automatiserade funktioner prioriterades bort och den avslutande testkörningen fick senareläggas. Elfel i systemet som påverkar varvtalsreglering bör ses över innan systemet kan anses färdig att ta i drift. 

  • 82.
    Andersson, Joakim
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energibesparande åtgärder i en fastighet med skilda verksamheter.2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Houses in Sweden stand for a third of its annual final energy usage. Almost 60 % of this is used to heat the houses of the warm water used in it. A measure to reduce our impact on the environment is to increase of energy efficiency by the year 2020. The construction of new buildings in Sweden is relatively low when compared to the total amount of houses currently in use, this is why the need to not only build new efficient buildings, but to also refurbish the current housing stock is important.

    HSB is one of Sweden’s largest housing cooperative and has associations and real estates all across the country. HSB Umeå is one of 31 regional associations and has approximately 8 000 members. In addition to administer the real estate of its housing associations they also own their own real estate. One of those is the house Balder 9, an apartment building with 39 apartments, one office, two stores and one restaurant and was built 1984.

    The purpose with this study was to make a model of the house using current energy statistics, the energy usage of the house, and the blue prints of the house, this so that a number of energy saving measures could be tested on the energy usage of the house in the energy calculation program BV2. BV2 was chosen because the program is designed to examine similar problems, and has a flat learning curve in comparison to similar software. The measures that were tested were divided into three categories that affected the energy usage, one was measures on the climate shell of the house, one was measures affecting the heat usage and the last affected the electricity usage of the house. In addition to the three categories of measures, heat recovery from the exhaust air of the restaurant and the gray water from the house were calculated using values from the model.

    When the measures had been simulated one by one and the result analyzed, three joint measure packages was simulated on the model. These three were divided into measures that lowered the energy usage, measures that paid back their investment cost, and measures that only were simulated in BV2.

    The results given by the simulations was that the measures one by one lowered the energy usage of the house by 1,0 – 5,0 %. The measures that led to the highest saving in energy usage were the measures that lowered the electricity usage for lighting and power appliances, and the measure lowered the inside temperature. The simulation of the three joint measure packages resulted in a reduction in the energy usage by 14,4 – 20,8 %, and a reduction in the emission of carbohydrate equivalents by 15,9 – 18,3 %. The results showed that measures to increase the energy efficiency of buildings should be implemented in joint measure packages in order to attain a higher level of savings in buildings energy consumption that can be reached by individual saving measures.

  • 83.
    Andersson, Joel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Ombyggnadsförlag för Alneskolans slöjdsal2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The crafts teacher on Alne elementary school in Örnsköldsvik, Sara Edström, believes that the wood working hall of the school is narrow and impractical. She believes that the hall has many flaws according to the valid demands regarding the work environment. The purpose with this study is to get enough material to show the crafts teacher how the wood working area could possibly be more effective, more pleasant and more satisfying to the valid laws and recommendations. The prepared material contains a floor plan drawing, a demolition plan drawing, a room description and calculations on how to cost them. This material is supposed to be used to get a real conversion of the formation of the wood working hall. The formation was based on the rules by the Swedish building regulations (BBR), the recommendations of the work environment authority´s and the instructions from the crafts teacher. The results shows that the wood working hall can be transformed to a more effective, more satisfying and more secure area. The wood working hall can be transformed in a way that meet all the rules and recommendations and most of the instructions given to a cost of 125 000 Swedish kronor.

  • 84.
    Andersson, Josefin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utredning av värmesystem i Boliden AB:s anläggning vid Tara-gruvan2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the summer of 2009, WSP visited a facility adjacent to the Tara-mine at Navan, Ireland. The purpose of their visit was to control the ventilation system which was outdated. During the visit the inspector detected that their heating system also was in need of updating and that task led to this bachelor thesis.

     

    The overall aim of this work is to investigate how a modern heating system can be assembled to improve the indoor climate compared to an older system, where the primary target is to develop a proposal for the formation of a new system that meet the power requirements and today's climate demands.

     

    The study refers to a facility used as a changing room for the miners and as an office premise. The analysis focuses on the changing rooms as the indoor environment is especially inadequate with temperature and relative air humidity above recommendatory values for good indoor climate. In addition, the system is heated with large amounts of oil which contribute with large contaminations to the environment. Being able to moderate the impact the facility contribute to the surroundings is an additional motive for any investment.

     

    The analysis began with an examination of the system demands from the facility’s needs, followed by a search of potential components which could optimize a contemplated system. In order to be able to build this system theoretically correct the thesis established a flow chart. On the basis of the flow chart, the system components is conform adjusted to the facility’s needs, which includes the heating of domestic hot water, ventilation- and heating systems, as well an air dehumidification unit in the locker room. To examine the possibilities of improving the energy efficiency of this heating system, the project will evaluate heat exchangers, a heat pump and a dehumidifier, and a coupling to the existing ventilation and heating systems.

     

    The results are presented as a theoretical system that reduces the facility’s energy consumption and improves indoor climate. By utilizing the accessible thermal energy, the project also presents the economic advantages from choosing an efficient heat pump within the system.

  • 85.
    Andersson, Kennet
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Manchester, Ian R
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Andersson, Nina
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Shiriaev, Anton
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurology.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Assessment of cerebrospinal fluid outflow conductance using an adaptive observer-experimental and clinical evaluation2007In: Physiological Measurement, ISSN 0967-3334, E-ISSN 1361-6579, Vol. 28, no 11, p. 1355-1368Article in journal (Refereed)
    Abstract [en]

    Idiopathic normal pressure hydrocephalus (INPH) patients have a disturbance in the dynamics of the cerebrospinal fluid (CSF) system. The outflow conductance, C, of the CSF system has been suggested to be prognostic for positive outcome after treatment with a CSF shunt. All current methods for estimation of C have drawbacks; these include lack of information on the accuracy and relatively long investigation times. Thus, there is a need for improved methods. To accomplish this, the theoretical framework for a new adaptive observer (OBS) was developed which provides real-time estimation of C. The aim of this study was to evaluate the OBS method and to compare it with the constant pressure infusion (CPI) method. The OBS method was applied to data from infusion investigations performed with the CPI method. These consisted of repeated measurements on an experimental set-up and 30 patients with suspected INPH. There was no significant difference in C between the CPI and the OBS method for the experimental set-up. For the patients there was a significant difference, −0.84 ± 1.25 µl (s kPa)−1, mean ± SD (paired sample t-test, p < 0.05). However, such a difference is within clinically acceptable limits. This encourages further development of this new real-time approach for estimation of the outflow conductance.

  • 86.
    Andersson, Kennet
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Manchester, Ian R
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurology.
    Eklund, Anders
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF). Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Real-time estimation of cerebrospinal fluid system parameters via oscillating pressure infusion2010In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 48, no 11, p. 1123-1131Article in journal (Refereed)
    Abstract [en]

    Hydrocephalus is related to a disturbed cerebrospinal fluid (CSF) system. For diagnosis, lumbar infusion test are performed to estimate outflow conductance, C (out), and pressure volume index, PVI, of the CSF system. Infusion patterns and analysis methods used in current clinical practice are not optimized. Minimizing the investigation time with sufficient accuracy is of major clinical relevance. The aim of this study was to propose and experimentally evaluate a new method, the oscillating pressure infusion (OPI). The non-linear model of the CSF system was transformed into a linear time invariant system. Using an oscillating pressure pattern and linear system identification methods, C (out) and PVI with confidence intervals, were estimated in real-time. Forty-two OPI and constant pressure infusion (CPI) investigations were performed on an experimental CSF system, designed with PVI = 25.5 ml and variable C (out). The ARX model robustly estimated C (out) (mean C (out,OPI) - C (out,CPI) = 0.08 μl/(s kPa), n = 42, P = 0.68). The Box-Jenkins model proved most reliable for PVI (23.7 ± 2.0 ml, n = 42). The OPI method, with its oscillating pressure pattern and new parameter estimation methods, efficiently estimated C (out) and PVI as well as their confidence intervals in real-time. The results from this experimental study show potential for the OPI method and supports further evaluation in a clinical setting.

  • 87.
    Andersson, Magnus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Björnham, Oscar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Bullitt, Esther
    Department of Physiology and Biophysics, Boston University School of Medicine, 700 Albany St., Boston MA, USA.
    Svantesson, Mats
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Uhlin, Bernt Eric
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Differentiating pili expressed by enterotoxigenic and uropathogenic escherichia coli with optical tweezersManuscript (preprint) (Other academic)
    Abstract [en]

    Enterotoxigenic Escherichia coli (ETEC) attach to the host epithelium in the intestinal tract via specific adhesion organelles expressed on the cell membrane. We investigate, by force measuring optical tweezers, the intrinsic biomechanical properties and kinetics of the colonization factor I (CFA/I) at a single pilus level. The measurements indicate that CFA/I pili are helix-like structures that can both be unraveled to a linearized polymer by applying a small external force, 7.5 ± 1.5 pN but also regain its helix-like structure when the applied force is reduced. The data confirm that layer-to-layer interactions, that stabilize the helix-like structure, are much weaker than the interactions found in pili expressed by Uropathogenic Escherichia coli (UPEC). It is also found, contrary to previous results assessed from UPEC pili, that the CFA/I undergo in some cases a sudden structural change, a force drop of ~2 pN, when unraveled from the helix-like configuration to an open helical linearized fiber. These data suggest a rotation of the filament about its helical axis, followed by a region in which the force required to extend the pili further increases rapidly. During this final elongation to a super-extended fiber, CFA/I pili do not show any structural transition as seen for UPEC pili. In addition, the CFA/I pili show faster kinetics than UPEC pili that allows for a larger dynamic regime of in vivo shear forces. The unfolding and refolding possibility points toward an organelle that has evolved to allow for dynamic damping of external forces and handling of harsh motion without breaking.

  • 88.
    Andersson, Maja
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Enhancing content discovery in Video on Demand services for children2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The media landscape is changing and Internet-based streaming services for children are becoming increasingly popular. The concept of online streaming extends freedom and control over content selection but discovering new content is often experienced as troublesome. The objective of this thesis is to identify parameters to make it easier for users of streaming services for children to discover and watch unfamiliar programs. Guidelines are formed based on literature studies, interviews, observations, a survey, a benchmark, data analysis with Adobe Analytics, a workshop and finally user tests with prototypes. These guidelines conclude that content should be categorized, dynamicized, highlighted and socially engaging. Categorization based on age is primarily important but interests and genres can also be used to make children more interested in a title. Content should be dynamic, customizable and personal to each user to give more accurate recommendations based on age and interests. Making one alternative more visually prominent will make this alternative more interesting especially for younger children and social features with information about other users opinions can motivate a decision to discover new content among older children. 

  • 89.
    Andersson, Marcus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    A new energy strategy for controlling heating and ventilation systems for existing offices2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project shows a house that consists of two identical offices. This model is implemented into the energy simulation software IDA ICE. The thermal characteristics of the building envelope are set according to the Swedish Building regulation code of 1975 (1). The heating ventilation air conditioning system consists of water panel radiators and an air handling unit. These components are designed in order to fulfill the winter design conditions. The heating system is connected to a hot stratified tank whereas a cooling tank provides the cold flow to the air handling unit during summer time. Different local controllers of the panel radiators are tested in order to investigate both the behavior of the indoor temperature and the mass flow of the fluid. The results shows the tradeoff between the temperature of indoor air and the mass flow rate provided to the panel radiators. The P-controller regulates the amount of mass flow rate to the panel radiator according to the level of indoor temperature. It shows a more stable indoor temperature but more instable mass flow rate. The ON/OFF thermostat, set as control, shows large oscillations of indoor temperature and mass flow rate meanwhile the P-controller with set-point signal shows good potential, but when a higher proportional band is used both the temperature and mass flow rate becomes more instable. A PI-controller shows an indoor temperature more stable than the other controllers but an instable mass flow rate. Moreover, the electrical consumption of the auxiliary devices, such as the circulating pump are analyzed for a whole year. Huge differences in the electrical consumption of the circulating pump are detected just by selecting different control strategy. The first strategy used is with a thermostat measuring the outside temperature, this resulted in an electrical consumption almost twice as high as the second strategy. The second strategy is a P-controller with set-point signal that constantly measures the indoor temperature, which showed to be a good strategy for controlling the circulating pumps.

  • 90.
    Andersson, Marcus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Erfarenhetsåterföring på NCC i Umeå2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Successful experience feedback is not common among constructing entrepreneurs since it is hard to practice. NCC in Umeå is one of many constructing entrepreneurs that consider themselves to be poor in this field, which is the reason why they requested a study to be carried out in their organisation. The goal is, inter alia, to identify the current situation. This in order to clarify the attitude towards experience feedback within the organisation. The study leads to a suggestion of how NCC should work with experience feedback in the future, in order to improve it.

     

    A literature study was made with the purpose of gathering enough knowledge, for example about experience feedback, quality and constant improvement. This theory is the foundation on which the further parts of the study rests; the interviews and observations within the company. These interviews and observations aims towards creating an overall picture of the current situation in the company. Moreover they generate primary data on how the organisation wishes to work in order to improve experience feedback. The result of the interviews and observations are analysed together with the theory as reference. This leads to the conclusions which are drawn about how NCC can improve their experience feedback.

     

    The lack of prioritise of experience feedback is the major contributory factor to why experience feedback does not function in the current situation. This since the board have an absence of engagement on the field. Therefore, the needed time for reflection and analysis after a finished project is not given. Another important reason to why the organisation finds experience feedback difficult is the lack of a functioning system of documentation.

     

    In the future, NCC should allocate the time required for a successful work with experience feedback. The board should become more active in this matter and look upon this work as an investment, since it can increase the effectivity in the organisation and reduce the quality deficiency. One person in each project should be in charge of compiling and documenting experiences. These experiences then needs to be labelled and documented in a digital database in order to enable an easy search. These documents should content a summary of the project, protocols from the final meetings, contact lists over the staff involved and a key figure with the sum of all costs from the calculation. Moreover, a compilation with pictures and explanting texts from each part of the building is recommended. This since visualisation was described as an important tool for experience feedback during the study. 

  • 91.
    Andersson, Martin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Isolerad DC/DC-omvandlare2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Cross Control is a company that produces embedded computer solutions. A computer’ s normal input voltage is 18-30 VDC and consumes at the most 50W. The computers are sold to several different customers, who use them in anything from forwarders to trains. In separate vehicles the supply dc current varies from one vehicle to another. This creates needs to convert the voltage to a level that the computers can handle. Such a device is called a DC/DC-converter. Voltage conversion can be performed in different ways, either through linear regulation, or by using switching technology. The goal of our work is to design a DC/DC-converter that meets the requirements raised in cooperation with CrossControl. To achieve sufficient efficiency, and since galvanic isolation between input and output voltage is a requirement, the converter is based on a switched flyback solution. The transformer is the most important component for the converter function. Therefore, a large part of the project was focused on selecting a suitable one. The result is a prototype that is capable of regulating the output voltage to 24VDC for the entire input range, and can handle a load of 50W. The effectiveness ended at 80% which is 5% below target. To improve the prototype it is necessary to protect it from voltage outside input range. To achieve 85% efficiency one could redesign the snubber network.

  • 92.
    Andersson, Oscar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Miljonprogrammet: Riva eller renovera?2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A lot of houses from the Million Homes Programme are currently in need of several major renovation measures. These houses have significantly higher energy consumption than today's construction requirements allow. With new goals from the EU and the Swedish government that will soon be standard, it is important that something is done about these energy consuming buildings. The purpose with the report is to compare a renovation option with a new production option. This is done from an economic point of view and from anenergy point of view. The goal is to propose the most profitable option. To reach this goal programs such as Revit Architecture, IDA ICE and BidCon are used, as well as literature studies. The result shows that it is more profitable to renovate the existing building rather than demolish it and build a new one. By renovating the building, the total cost is significantly lower compared to the new production option. The energy consumption almost becomes the same. From the residents' perspective, the renovation option is also seen as the most profitable option since the rent for this option is much lower than for a newly built home.

  • 93.
    Andersson, Oskar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Achieving energy efficiency and indoor climate: A comparison of varying control system and building envelope modification2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis investigates the performance of varied control systems in a office building in the southern parts of Sweden. The control system is designed according to standard EN15232 with three levels of building automation and control systems with a multi-zone approach. Highest standard, class A, is a demand control system with VAV controlled by temperature and CO2-levels in each zone. The lighting in class A is controlled by user demand and dimmers with regard to daylight to meet lighting regulations. The ventilation in the middle system, class B, is VAV controlled by temperature and demand in a zone. lighting is only on when a zone is used but no opportunity to dimmer. The reference object, class C, uses constant air volume CAV based on Swedish regulation and has lighting as in class B. The building envelope is varied between an existing model with 70Às building standard, according to todayÀs standard, and passive house standard in Sweden. All simulations is evaluated through energy performance and indoor climate in terms of temperature, PMV, PPD and CO2-levels.

    Simulations showed that the class A system has the highest possibility to decrease the energy use compared to the other systems. The reduction in total energy use differs from about 9-27% compared to class C and about 29-34% in electric energy use. Simulations also showed that class A and B are more advantageous to apply in a passive house rather than in the existing building if the total energy is evaluated. With regards to electric energy use, the difference between the building envelopes is too small to state that any difference exists. Neither one of the systems corresponds to ”good” indoor climate in the critical zones, all three is between the range ”good” and ”acceptable” according to standard SE-EN15251. Class A and B show an overall improvement of PMV and PPD compared to class C system. The class B system is closest to fulfill a ”good” indoor climate, especially in the passive house model. Evaluation with respect to CO2-levels class A and C showed acceptable levels.

  • 94.
    Andersson, Pierre
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektivisering genom dynamisk uppvärmning av en byggnad.2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Akademiska hus förvaltar Umeå Campus och har problem med att användningen av fjärrvärme överskrider den abonnerade effekten på deras abonnemang. Av den anledningen så valdes det att genomföra olika simuleringar av Teknikhuset där institutionen för Tillämpad Fysik och Elektronik är en av hyresgästerna. Med hjälp av simuleringar undersöktes möjligheten att undersöka olika konfigurationer och åtgärder.

    En modell skapades i IDA-ICE efter ritningar och de verkliga årliga behoven för fjärrvärme och el. Därefter användes modellen för att testa olika konfigurationer under kalla dygn där temperaturen kontinuerligt är mellan -18 till -25. Resultaten indikerarar att det finns möjlighet att sänka värmen i vissa rum som resulterar i ett minskat effektbehov vilket stämmer väl överens med hypotesen för scenariot. Ett av det andra problemen som förutspåddes var det fanns möjlighet att det skulle bli ökat missnöje av det termiska klimatet. Det på grund utav problem i närliggande rum och lokaler men det visade sig vara mycket begränsad påverkan av det.

    Det kalla dygnet visar att byggnaden uppvärm på det traditionella vis jämfört med en dynamisk uppvärmningsmodell skulle göra det möjligt att sänka effektbehovet med 9 % ifall man väljer att inte värma upp en av de tre våningarnas salar. Genom att göra en analys av hur bokningen av salarna visar det att det finns möjlighet att inför ett system där vissa lektionssalar som inte är bokade stängs för användning. Det skulle kunna skapa en lägre sänkning per dygn men på grund av de kontinuerliga användandet skulle det resultera i en större vinst. En simulering över möjligheterna att stänga av en lektionssal på våning två, tre och fyra i Teknikhuset gav en årlig effektsänkning med 1,2 % av fjärrvärmebehovet som om det extrapolerades ut över hela campus skulle spara på 100 000 kr per år. 

  • 95.
    Andersson, Pär
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Frakt-och paketritning för KL-trä i Tekla2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this project has been to set up a freight drawing with accompanying packages drawing for CLT-wood in the program Tekla. This is based on the requirements for freight according to the Transport Agency and what applies to handling of the CLT boards regarding the working environment hazards. Based on the problems and requests from Martinsons, this project resulted in a freight drawing with accompanying package drawing. The package drawing is going to be a helpful tool for the project manager in the manufacture of the CLT boards. The freight drawing is going to provide comprehensive information about how to load the packages on the loading platform.

    The project is based on a reference model called Tallbocken, which is the model that Martinsons have used before. The model is basically a building, four floors tall, made almost entirely of CLT wood. An instruction has been made, based on this model, for the establishment of freight- and package drawing. A study has been made to ensure the demands from the Transport Agency regarding the shipping of compound elements. By visiting the production line in Bygdsiljum it was clear that the staff wanted a change in how to handle the CLT boards. Information about how to handle this was also an important message on meetings with the project manager and the production staff at the fabric in Bygdsiljum. To make sure that the drawings keep in line with the recommendations, there is an explanation for the review of building documents 90’s.

    This working project has resulted in an instruction for how to manage the establishing of freight- and package drawing. The instruction is attached as a supplement to this essay. This instruction explains the procedure step by step for how to create a freight drawing for CLT wood in Tekla structures by using a complete project template. 

  • 96.
    Andersson, Robin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utredning av slaggning vid förbränning av träpellets i värmeanläggningar: I sammarbete med Härjeåns Energi AB2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    The member states of the UN have united behind a convention on climate change 2015, the “Paris agreement”. To face the challenges of a required conversion to renewable energy, the dependence of fossil fuels need to be drastically reduced. Combustion of biomass has a god potential to replace fossil fuels in many applications. Pellets made from stemwood has a high energy value and is a good candidate to replace fossil fuels in small and medium scale heat and power production. To make pellets more attractive on the market, the delivered pellets need to have high quality and enable low maintenance and operational problems during combustion. Härjeåns Energi in Sveg would like to know more about the ash related issues like slagging and sintering, and how it can be avoided be measures related to handling, pellet production and end use (combustion). The overall objectives of the present work was to identify ash related problems during combustion of wood pellets in heating boilers, focusing on sintering and slagging, and to provide recommendations on measures how to avoid such problems for producers and individuals.

    This work with the report was divided into two parts. The first part included a research review on the subject. The second part included an investigation of the handling by Härjeåns Energi and their subcontractors. The research review was carried out by reading the research, mainly in scientific peer- review papers from the last 25 years. The investigation of the handling was carried out by evaluating analysis data of pellets, raw material and slagg samples.

    The results showed that the most important factor that influence slag formation is the concentrations of certain ash forming elements in fuel, such as silicon, potassium, calcium, sodium, magnesium aluminum and iron. Also ash content, combustion technology and combustion temperature are of importance. Substances in the fuels that are associated with slagging tendencies originate mainly from different kinds of contaminations, e.g. sand, soil and clay. This is most likely the case for Härjeåns Energi. The results also showed that the ash fusion temperatures of the raw material ash where constantly high during the weeks of the summer 2016. The remaining weeks of the year showed more varying ash melting temperatures. The produced pellets from Härjeåns Energi 2016 had a high ash molting temperature during the year of 2016, except in October. The exact reason behind the relative low ash melting temperatures is difficult to point out specifically in this work, and need more careful investigations. Overall, it is the pellets producer, the subcontractors and the manufacturer of the heating devices that have the possibilities to develop product and measures which avoid or reduces slagging related problems. The end users (customers) have very small opportunities to influence the outcome of the combustion of pellets. 

  • 97.
    Andersson, Ronny
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Rosterkylning för biopanna-Ålidhems värmeverk2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Rosterpannor är en väl beprövad förbränningsteknik som är vanligaste pannan för små och medelstora anläggningar i Sverige. Det finns många utföranden på rosterpannans rosterbädd som alla har sina för och nackdelar. Dock delar de samma problematik vid eldning av bränsle med ett högt värmevärde såsom biobränslen. Det höga värmevärdet leder till en hög förbränningstemperatur som tillsammans med många andra parametrar ger upphov till korrosion på pannans inre delar, däribland rosterbädden. Det finns två typer av rosterkylning, där ena är luftkylning och andra mer effektiva metoden är vattenkylning.

     

    Panna 7 är en del av Ålidhems värmeverk som används av Umeå Energi till att kapa effekttoppar hos fjärrvärmen. Denna panna eldar returträ med högt värmevärde och har problem med rosteröverhettning i rosterzon 2 vilket är i mitten av längden på hela rosterbädden. Rosteröverhettningen ger upphov till att rostret bryts ned och förutom det försämrar rosterbäddens alla funktioner för en optimal förbränning hos pannan. Denna rapport agerar som en dokumentationshandling åt UE som stöd  för P7:ans brister och lösningar på rosteröverhettningen. Rapporten innehåller kvantitativa lösningar som sedan fungerar som en förstudie vid intresse att genomgå en fördjupad undersökning innan förlagen implementeras i P7:an.

     

    Efter att ha undersökt rosteröverhettningen lokaliserats åtta olika förbättringsåtgärder som innefattar: kylning av stavarna i rosterbädden, utjämna primärlufts- och bränsleflödet, sänkning av värmevärdet hos det befintliga bränslet, konvertera till fluidbäddspanna och rökgaskondensering för att ta tillvara på fukten som vissa lösningar tillsätter till förbränningen. Där antingen konvertera till fluidbäddspanna eller installera vattenkylda stavar är dem mest tänkbara lösningarna vid fortsatt eldning av returträ. Konverteringen anses vara den mest framtidssäkra lösningen, men också den mest omfattande. Vattenkylda stavar är därför den åtgärd som verkar mest lovande eftersom en sådan lösning inte bara kyler stavarna, utan även gör så att förvärmningen av primärluften och luftmängdsfaktorn till förbränningen optimeras. Tidigare studier visar att det inte är tillräckligt ekonomiskt försvarbart med en rökgaskondensering för den aktuella returtemperatur på fjärrvärmen som kommer in till anläggningen. Vidare undersökning måste utföras för att kontrollera ifall anläggningen Graniten, som i dagsläget värmer returvattnet, kan förbikopplas.

  • 98.
    Andersson, Sara
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energisparåtgärder i samband med påbyggnad av nya bostäder: En fallstudie av Röda längan i IDA ICE2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    As older buildings in our housing stock are in increasing need of extensive renovations, it further enhances our social requirements. It is then needed alongside with renovations to find whole measures that yields energy savings which also is financially profitable.

     

    In this report, we examine the possible energy savings alongside with the profitability of the energy measures connected with extensions of new housing on top of an existing housing. The current heating system of the building is replaced with geothermal heating, which is also working through to the ventilation system. Thereafter the building is extended with three new floors. The report also evaluates if an extension of new housing in the individual case is to be seen as an extension or a reconstruction, together with the demands of which are put on an altered building in accordance to PBL and BBR.

     

    With the help of the computational energy software IDA ICE, the affect from the different energy measures could be studied. The yearly economical savings was then compared to the cost of the different measures. The measures were deemed profitable if the value of the yearly savings exceeded the initial cost.

     

    For the specific case, the measures of energy savings gave an considerable improvement for the extension, both in energy but also in the economical sense. The investment of the extensions is to be seen payed via sales of apartments, and the payback on the actions taken on the existing building is estimated to within 10 to 15 years. for the individual case the possible yearly energy savings, after completed measures, is upwards of 74 percent, which translates to 130 kWh/m2 per year. This report also states that, in specific case, extensions of new housing is to be seen as an extensions and that four geothermal heating pumps are enough to reach sufficient energy savings together with economical profitability.

  • 99.
    Andersson, Sara
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Våningspåbyggnad av miljonprogrammets flerbostadshus: Simulering av energiprestanda i IDA ICE2016Student paper other, 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    During the years 1965-1974 around one million new housing were built in Sweden, this was also known as the “miljonprogrammet”. Today, nearly a third of the Swedish housing stock is from this particular period, and many buildings are reaching the end of their technical lifetime. After the new EU directives Sweden have decided on developing it's on national goals to achieve smart energy consumption. To speed up this development can the renovations of the existing "miljonprogrammet" executed in combination with storey extension.

     

    Sweden is also facing growing housing shortage, much like during construction of the “miljonprogrammet” as well as limited areas both in urban and densely populated areas. By refurbishing buildings from the “miljonprogrammet” in conjunction with a storey extension, new housing can be built in a resource and energy efficient way. This should also improve the energy performance of the existing building.

     

    In this project, the energy performance of an apartment building, typical from this time, was evaluated and then compared to a modified building with a storey extension. A reference house located in Nacka, Sweden was used to simulate the annual energy usage in the software IDA ICE. The simulation yielded an energy usage of 197.1 kWh/m2 for the reference building and 167.1 kWh/m2 for the building with a storey extension.

     

    After the project it became clear that a storey extension on a building from the “miljonprogrammet” improved the existing building's energy consumption. At best, a building like the reference house can improve the energy classification from energy class G to E. Residential densification using storey extension is beneficial in many aspects. In addition to lowering the total energy consumption of the building it also creates new homes in a resource efficient manner. Society must seek to create enticements for property owners to renovate and execute energy efficient measures on their properties. One such example would be three-dimensional property formation which is also an alternative form of financing investment such as a renovation.

  • 100.
    Andersson, Sebastian
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Centralised Distribution Grid Energy Storage Systems: Placement and Utilisation for Grid Expansion Deferment2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Following an ongoing change towards an increasingly renewable power generation system Swedish grid operators are facing several challenges in coming years. As authorities plan for the decommissioning of nuclear power an increased reliance on de-centralised energy sources such as photo-voltaic distributed generation (PVDG) is expected. A technology observed in some cases to accompany local power quality issues severe enough to impose grid expansion measures from distribution system operators (DSOs). Considering a combination of an indicative utilisation inefficiency of classical grid expansion measures and a recent year maturing of various energy storage technologies, this report sets out to evaluate the possibility of utilising centralised energy storage systems (ESSs) for deferment of classical grid expansion measures.

    For the purpose of identifying the most prominent problem scenarios of modern production- and consumption behaviours as well as the possible solutions offered by centralised ESSs, a literature review of journal articles and technical reports was conducted in combination with a case-study of an existing urban grid operated by Umeå Energi Elnät AB (UEEN). The work regarding ESSs is directed with specific focus towards evaluating which ESS services can potentially facilitate grid expansion deferment and what ESS placement is advisable for efficient utilisation. Assessing possible grid safety implications, potential for peak load shaving and the presently most suitable energy storage technology was also within the scope of the study.

    The literature review reveals PVDG induced feeder line over-voltage and transformer overload the most likely and previously observed implications imposing grid expansion measures. The former more prominent in elongated, typically rural, grids and the latter in more densely populated urban grids. For deferment of over-voltage related grid expansion measures a centralised ESS can be utilised for voltage support provided placement is made close to the affected grid section, presumably far out the affected feeder line. This result is coherent throughout the reviewed literature and is supported by the results of the case-study. Distribution transformer overload and its imposed grid expansion measures can be deferred through load re-allocation and peak load shaving, two services proven achievable by centralised ESSs and the capacity for which increases if ESS placement is made closer the distribution transformer.

    Provided present regulatory and standards are adhered to upon installation, significant negative impact of centralised ESSs on distribution grid safety can be avoided. Most energy storage technologies, including battery based energy storage technologies indicated from the literature review providing the most suitable characteristics for use in centralised distribution grid ESSs, utilise well established systems for grid connection hence no presently unsolvable grid safety implications are identified. Technical reports of real applications of centralised ESSs reinforce this argument as successful implementation without ESS caused grid safety implications have been achieved in the Swedish distribution grid in the past.

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