hig.sePublications
Change search
Refine search result
1234567 151 - 200 of 4067
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 151.
    Andersson, Lina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Lärares tankar och idéer kring musik i idrottsundervisningen2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att undersöka hur och varför lärare i ämnet idrott och hälsa på gymnasiet använder sig utav musik som ett pedagogiskt verktyg samt varför de inte använder musik. Syftet är även att undersöka om gymnasielärarna i ämnet idrott och hälsa blir påverkade av några yttre faktorer som kan resultera i att de använder musiken i sin undervisning. Studien är baserad på kvalitativa intervjuer med åtta lärare i ämnet idrott och hälsa på gymnasiet. Resultatet visar att lärarnas tankar och idéer kring användandet av musik samt hur de upplever att eleverna agerar till musik stämmer bra överens med tidigare forskning som visar många fördelar med att arbeta till musik. Resultatet visar även att de yttre faktorer som påverkar lärarna mest, när det gäller hur det använder sig utav musik i deras undervisning, är eleverna och deras musikintresse. Slutsatsen av studien är att lärarna upplever att musik motiverar och inspirerar elever till rörelseglädje samt en högre prestationsnivå. Hur de använder musiken är antingen som bakgrundmusik eller som ett hjälpmedel.

  • 152.
    Andersson, Linda
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Hedlund, Johanna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Trivsam boendemiljö för studenter: En gestaltningsstudie utifrån studenters åsikter för ett trivsamt boende2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The physical environment is a very important component for human health.  A well-functioning site enables people to recreation and social life. People who spend a lot of time outdoor are also experiencing less stress. If people doesn’t give opportunity to influence the spatial planning process there is a risk of negative attitudes and discomfort. This can create a mental illness. This study deals with how students feel about their physical environment and how they want it to be designed. The study is aimed at students who live in one of the three different student areas in Gävle: Kungsbäck, Campus Sätra and Midgård. The study is based on three methods. These were: a questionnaire, an observation study, and a physical design study in 3D.

     

    The observations showed significant problems with the site design as only movement, who take into necessary but significant activity account. The observations showed a clear lack of both elective and social activities, both of which are important for a well-functioning place. The survey showed dissatisfaction about the site design among the students. Through this study, students were given an opportunity to share their wishes about the site's future design. The proposals were designed in 3D. Three different proposals were developed: a zero option, an economical option, and an expensive option. The zero option indicates a probable development of the area if no action takes place. The economical option indicates a solution that focus on economical sustainability. The expensive option has the highest costs both in construction and maintenance. The evaluation showed that the students liked the economical proposal option most.

     

    The result showed the importance of student participation in the planning process. Student comments through the survey and evaluation, indicated that: trees, venues, water, grass and lighting should be included in future planning frameworks for student housing.

  • 153.
    Andersson, Lorraine
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Pedagogisk verksamhet i botanisk trädgård- mer än växtkunskap2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I dag då allt fler människor bor i städer blir konsekvensen att kontakten med naturmiljöer minskar. Botaniska trädgårdar är då en betydelsefull plats för rekreation och välbefinnande i urban miljö. Allt sedan de första moderna botaniska trädgårdarna i mitten av 1500-talet anlades har undervisning varit en viktig del av trädgårdarnas verksamhet.

    Syftet med studien har varit att undersöka några botaniska trädgårdars pedagogiska verksamhet. Fokus har lagts på att ta reda på hur trädgårdarna arbetar med pedagogiska/sociala projekt. En central utgångspunkt i botaniska trädgårdarnas pedagogiska och sociala verksamhet är människans beroende av växter. För att inse växterna/naturens betydelse för människors vardagliga liv har det visat sig att tillämpad botanik är den metod som allmänheten har haft lättast att ta till sig.

    Tre svenska och tre utländska botaniska trädgårdar valdes ut för att ingå i studien. Metoden jag använt mig av är litteraturstudier kombinerat med kvalitativa intervjuer. Framgångsfaktorer avseende den pedagogiska verksamheten, som sker i de botaniska trädgårdarna, är bland annat samarbete med andra organisationer samt möjligheten till delaktighet i närområdets aktiviteter. Odlings- och trädgårdsprojekten genererar positiva effekter både för individen och lokalsamhället. Under studiens gång har mer och mer framkommit, att botaniska trädgårdar är en viktig resurs vad gäller att driva och utveckla en pedagogisk/social verksamhet.

     

  • 154.
    Andersson, Magnus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Bergviksäpplet och dess fruktsättning2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Trees of Bergvik apple (Bergviksäpple) planted between 2001 and 2007 have shown varying harvest. This study investigates why some trees gets low or no harvest while others get significantly higher harvest. The aim is to identify some reasons why fruiting differs between the trees and if possible suggest and/or enlighten the tree owners what can be done to improve fruiting. The study includes 25 trees, mostly located in Hälsingland, Sweden. The tree owners have answered two questionnaires, first in the spring with questions regarding flowering and the second in the autumn, regarding harvest. The answers to these questionnaires form the foundation for this work.

    The result of the study reveals differences in harvest. Older trees and/or trees with good vegetative growth have larger harvest while trees with poor growth in some cases didn’t even get flowers. Younger trees with good growth gave good harvest. This concludes that the single most important factor to get good harvest is good vegetative growth.

  • 155.
    Andersson, Marcus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Programmering i skolan: Vad är det enligt lärarna?2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna uppsats är främst att undersöka hur lärare definierar begreppet programmering och hur definitionen inverkar på undervisningen. Undersökningen har genomförts med hjälp av metoderna enkätundersökning och intervjuer. Olika uppfattningar förekom, inte minst bland respondenterna i enkätundersökningen, men de intervjuade lärarna definierade programmering främst som att styra någonting. Deras beskrivning av den genomförda undervisningen antyder att denna uppfattning inverkar på utformningen av undervisningen. Det relativt begränsade underlaget i undersökningen gör att resultaten är svåra att generalisera.

  • 156.
    Andersson, Maria
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Bland mossa och småkryp -att stimulera barns intresse förnaturen med hjälp av uppdragskort2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 157.
    Andersson, Maria
    et al.
    Department of Psychology, University of Gothenburg, Göteborg, Sweden .
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering.
    von Borgstede, Chris
    Department of Psychology, University of Gothenburg, Göteborg, Sweden .
    The Effects of Environmental Management Systems on Source Separation in the Work and Home Settings2012In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 4, no 6, p. 1292-1308Article in journal (Refereed)
    Abstract [en]

    Measures that challenge the generation of waste are needed to address the global problem of the increasing volumes of waste that are generated in both private homes and workplaces. Source separation at the workplace is commonly implemented by environmental management systems (EMS). In the present study, the relationship between source separation at work and at home was investigated. A questionnaire that maps psychological and behavioural predictors of source separation was distributed to employees at different workplaces. The results show that respondents with awareness of EMS report higher levels of source separation at work, stronger environmental concern, personal and social norms, and perceive source separation to be less difficult. Furthermore, the results support the notion that after the adoption of EMS at the workplace, source separation at work spills over into source separation in the household. The potential implications for environmental management systems are discussed.

  • 158.
    Andersson, Martin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Berge, Nils
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Energi- och miljökonsekvenser vid energieffektivisering av belysning och installation av solceller på Nacka Forum i Stockholm2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The use of energy is increasing worldwide and due to the threat of global warming more and more discussions are made about how the consumption could be reduced and at the same time more sustainable solutions is requested.Buildings consume 40 % of the total global energy where most of it comes from fossil fuels. To reduce the impact of the environment the EU (European Union) has set several goals for that where one is reducing its CO2-emission with 20 % compared to 2008 by the year 2020. One way to do so is from using more efficient technology. This work was made to reduce Nacka Forums electricity bills and that after it had been requested of their owner Unibail-Rodamco. The authors have only looked for solution in areas which the property owners are responsible for like services areas and public spaces. Ideas for reducing their energy use were obtained through studying literature. That study also showed that shopping malls use a lot of energy, especially electricity which mostly is consumed by the building’s lighting. Something that is becoming increasingly more common on buildings is solar cells. Solar cells do not only cut the electricity costs but also decreases the demand on fossil fuels. The shopping mall seemed to have good conditions for such an installation so an investigation was made to see if that could be useful. A plant with a power of 100 kWp was calculated to need 920 m2 roof surface and would yearly produce 93 534 kWh which the authors conclude that it would be a good investment and also highlights that an even bigger plant should be considered. After observing the lights two new solutions were proposed where LED-lamps was considered to be the best source for replacement. Just changing all the light sources would cut the electricity costs a lot but since the existing luminaires was considered to be at the end of their technical lifetime the best solution would therefore be to change both luminaires and light sources. Such solution would decrease the energy use with 544,4 MWh/year and has a payback period of 3,3 years. That energy saving would decrease the CO2-emission with 218 ton/year.This work shows that regardless of which solution that is chosen both of them would decrease the energy use and CO2-emission with 50 %.One of the stores in the shopping mall was using a lot of light which caused problem with the thermal comfort. Despite that, the store does not exceed the limit of 50 W/m2 that is set from the property owner. Such low requirements might hinder any efforts to reduce the energy use and also contribute to unnecessary heat.

  • 159.
    Andersson, Martin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Jonsson, Andreas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Nyström, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Insvällning av olimmade och limmade trädymlingar2019Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    Wood is a renewable material, unlike many other building materials. The amount of wood used in the construction industry can be increased by using wooden dowels as a substitute for screws and nails. Screws and nails are made of metals, which are non-renewable materials. The manufacturing process of metal-based materials is more energy consuming than it is for wooden materials and therefore it has a greater impact on our global environment.The purpose of this study was to investigate the adhesion capacity of wooden dowel-joints, non-glued and glued made out of beech and pine. The attachment of the non-glued wooden dowels was achieved by swelling of the wood. Swelling was achieved by first drying the wooden dowels in an oven and then letting them acclimatize with the surrounding materials and the relative air humidity. The adhesion capacity of the wooden dowels should be able to compete with the withdrawal strength of nails to be practically useful.Tensile strength tests have been carried out in the laboratory in house 45 at the University of Gavle to determine the adhesion capacity of wooden dowel-joints. The tensile strength tests were performed with a Shimadzu AG-X machine. The results of the tests have been compared with the theoretical withdrawal strength for nails. Characteristic strength values have also been calculated from the tensile strength test results for the wooden dowels.The results of the study shows that only the glued wooden dowels can compete with the withdrawal strength of nails. Glued wooden dowels can therefore be a substitute for screws and nails. The calculated characteristic values for glued beech-dowels and glued pine-dowels are 5,2 kN respectively 4,3 kN.

  • 160.
    Andersson, Martin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Meriä, Markus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Ruttoptimering i en georefererad mikrospatial miljö: ett GIS visualiserat i 3D2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    City models in 3D are a growing factor in GIS and it has been demonstrated that rescue times will be reduced for emergency services with the use of 3D GIS. The work presented in this thesis deals with network analysis in 2D and 3D and has been carried out on behalf of Gävle municipality. The task has been carried out with two main objectives. The first objective was to compare processing times for Dijkstra's search algorithm for networks (one smaller network based on the house of administration (förvaltningshuset) in Gävle and one overdimensioned network) in 3D and the corresponding ones in 2D in order to determine the difference. The second objective was to develop an application which allows 3D guidance for visitors from the reception to the required personnel; the resulting route is then obtained and visualized in a 3D model. The work has mainly been conducted with ESRI ArcGIS Desktop 10 and ArcGIS Engine Developer Kit 10. The programming has been carried out with C# in Visual Studio 2010. The application works by dynamically retrieving employee information from a table by using SQL-queries and individual routes are generated for each search. The analysis results for the process times show that there are no significant differences between the 2D and 3D networks. The conclusion to be drawn is that the process time is not a reason to opt out of a 3D environment for network analysis. In the future there is great potential for network analysis in 3D, especially in conjunction with 2D networks.

  • 161.
    Andersson, Martin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Olofsson, Marcus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Methods for Freezing Time with Computer Graphics Imagery2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The most effective method to create an illusion of frozen time in film media was explored for this research. Starting with a description and evaluation of different methods of achieving the effect, this document describes the implementation of a specific technique for a particular project to test freezing time. It was also established to aid students in their understanding of the process in both pre- and post-production. After testing and researching, the method of filming still-posing actors with a high speed camera was chosen. However, the testing and pre-production phase demanded a large amount of time, therefore for the remainder of the project only one scene was established. For budget and time consuming purposes the two recommended techniques are; camera projection and filming still-posing actors with a high speed camera. The choice between these two methods mainly depends on the amount of camera movement.

  • 162.
    Andersson, Martin
    et al.
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Sosa, Mario
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Sjöberg, Sören
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Mechanical Engineering.
    Olofsson, Ulf
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Effect of Assembly Errors in Back-to-Back Gear Efficiency Testing2015In: Power Transmission Engineeing, Vol. December, p. 72-77Article in journal (Other academic)
  • 163.
    Andersson, Mattias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Stenberg, Catarina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Effektivisering av interna transportsystem: Utformning av IT-stöd för fallföretag2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Att hantera den interna logistiken när marknaden är volatil och rörlig kan vara svårt. När avdelningar på företag inte kommunicerar eller delar information med varandra gör det att bistående företagsfunktioner, som interna transporter, får svårt att planera sina processer gentemot produktionsfabriker och marknaden, vilket kan leda till resursslöseri. För att underlätta arbetet och planeringen för den interna logistiken krävs att rätt teknik och förhållningssätt finns.

    Detta arbete tar fram en metodik som undersöker vilka faktorer som finns för att effektivisera den interna logistiken, samt hur ett IT-stöd för effektivisering kan utformas. Fallstudien avgränsas till interna transportsystem för de produktionsfabriker där sidlastare och grensletruckar utför transporter.

    Genom fallstudien på företaget visade det sig att de bristfälliga områdena var integrering och samarbete, kommunikation samt standardiserat arbetssätt. Detta försvårar arbetet med den interna logistiken och gör att företagsfunktionerna inte är synkroniserade i arbetet. Den bristfälliga informationsdelningen om framtida beläggningar och prognoser gör att planeringen av interna transporter mot produktionsenheterna inte fungerar önskvärt.

    I den teoretiska referensramen framgår att faktorer som påverkar effektiviteten av internlogistik är IT-stöd, arbetssätt och rutiner, planering och kommunikation samt resursutnyttjande. IT-stöd är något som kan hjälpa företag inom de bristfälliga områdena och vara en start till att integrera ett företags processer för att förbättra kommunikationen och informationsdelningen, som i sin tur ger bättre förutsättningar för att planera bistående företagsfunktioner till ett bättre resursutnyttjande.

    Genom metodiken för att effektivisera den interna logistiken påbörjas ett första steg av ett IT-stöd genom att en EXCEL-modell skapas som ett underlag för planeringsprocessen av interna transporter på fallföretaget. EXCEL-modellen skapas genom sammanförandet av historiska data från transportavdelningen och produktionsfabrikerna. Metodiken kan vidare användas för framtida undersökningar för effektivisering av den interna logistiken på företag.

  • 164.
    Andersson, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Energieffektivisering av byggnad med enkla medel: en fallstudie på Hofors mödravårdscentral2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the central parts of Hofors a healthcenter is located which is included in Hoforshus AB's building stock, the building itself is divided into a main building and a smaller one in which the child health center and maternity care is located. The buildings are connected by a corridor substantially glazed. Now they are interested in maping the building's energyusage as this is relatively high, in addition, the users of the building had been dissatisfied with the indoor climate in both summer and winter. Because of the healtcare activities the owners were most interested in finding solutions that would not interfere with it.

    The study conducted has had a primary focus on the building envelope and above all on the glazed corridor’s impact on the rest of the building. One can assume that the high proportion of glass in this part of the building affects the indoor climate negatively keeping in mind the low U-value of the glass and the solar heat load, this gives during the summer when heat gain is not desired. A literature study to investigate how people perceive the climate as well as how to make a reliable simulation model of a building has been completed. The study resulted in an understanding of how the indoor climate is perceived and quantified, and also in an understanding of what is important in the collection of data for the simulation model.

    Keeping in mind how data should be collected according to the literature reviwe- have as much data as possible measured through surveys and own observations, blueprints have been studied and their validity has been investigated by measuring the building, blower door has been performed and temperature- and relative humidityloggning. Instantaneous values of the FTX system was made to calculate its efficiency. Linear thermal bridges have been investigated by finite element method in the program COMSOL Multiphysics 3.5. For validation of the simulated model the results of it were compared with the acutal measured energyconsumption of the building. The simulations were performed in BV2.

    The results of the study show, as expected, the glazed corridor’s negative impact on the building's indoor climate. Temperature was logged between 160412-160509 highest temperature was 30 ° C and minimum 15 ° C, which is more widespread than in other areas where the temperature was logged. The simulations that were performed on the glazed corridor shows that it consumes between 5000-5500 kWh on the area of 13.5 m2. Finally the study resulted in recommendations for the building that includes additional insulation of the attic, replacement of a smaller wall section, lowering the temperature by 1 ° C, as well as some maintenance measures to improve the indoor climate. The measures are believed to be possible to implement without significant interference with the health care acitivities. In addition the proposed measures seem profitable according to the pay of method.

  • 165.
    Andersson, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Mechanical Engineering.
    Modelling of metal removal rate in titanium alloy milling2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Titanium is one of fourth most abundant structural metal in earths soil. It is in a composition with other elements, forming titanium alloys. These alloys are used in many different areas, such as medical, energy and sports, but is most commonly used in aerospace applications. Titanium alloys have different solid phases, α, α+β and β depending on temperature and the amount of α and β-stabilizers.When machining titanium alloys, one of the most important factors to control is the temperature in the cutting zone. The built-up heat in the cutting edge of the tool, are connected to titanium alloys low thermal conductivity and high heat capacity, which means that the alloy has low heat conduction from the cutting zone. The temperature is strongly depending on the cutting speed, which is the relative speed difference between the cutting tool and the workpiece. Many studies and research work have been conducted surrounding this fact, focusing on the physical and chemical quantities, to model tool wear progression and how this affects the tool life and the metal removal. These models are often implemented and analyzed in finite element software providing detailed but time-consuming solutions.The focus for this work have been on developing a suitable tool life expectancy model, using design of experiments in combination with metamodeling to establish a model connecting cutting parameters and measured responses in terms of tool life, from a conducted milling experiment. This models where supposed to provide a platform for customer recommendation and cutting data optimization to secure reliable machining operations. The study was limited to focus on the common α+β titanium alloy 6Al-4V. The outcome and conclusion for this study, is that the tool life is strongly connected to the choice of cutting speed and the radial width of cut and that these parameters can be predicted by the two models that have been develop in this project. The models ensure the highest possible metal removal rate, to selected parameters.

  • 166.
    Andersson, Per
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Utvärdering av tomtmark med multikriterieanalys och en vägnätsanalys för trafikförsörjning: en GIS-studie åt Motala kommun2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med denna studie är att med hjälp av geografiska informationssystem (GIS) finna ett område i närheten av Borensberg tätort som är lämplig för utökning av tomter för friliggande enfamiljshus. Inom det valda området ska sedan ett vägnät tas fram för trafikförsörjning. Vägnätet ska dras där lutningen är som lägst, binda samman det befintliga vägnätet och ge ett bra relationstal baserat på antal meter ny väg per antal nya tomter.

    Borensberg är en boendeort med ett ökande antal invånare. Därför har Motala kommun i en översiktsplan fastställt att det minst ska finnas tio byggnadsklara tomter för fristående villor i beredskap för försäljning varje år och även tomter för flerbostadshus med ett genomsnitt av fem lägenheter per år.

    Data som har använts för att genomföra analysen består av ortofoton, digital höjdmodell, ArcGIS data i vektorformat och egenhändigt tagna digitala fotografier. För att hitta ett lämpligt område användes sex restriktionskriterier och två ickerestriktionskriterier. För att konstruera ett vägnät med en så låg lutning som möjligt användes funktioner i spatial analysis tool i ArcMap.

    Resultatet visar att det, utifrån de angivna kriterierna, finns områden lämpliga för en utökning av samhället. Det ger även två alternativ för nytt vägnät för det utvalda området, planeringsområdet. Vad som dock kan sägas är att det är svårt att hålla vägnätet under de givna lutningskriterierna med de förhållanden som landskapet erbjuder. Kriteriet där tomtmark inte får överstiga 25 grader utgör inte några hinder. Hela området kan anläggas med tomter.

  • 167.
    Andersson, Rabé
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Electronics.
    Exploring Baxter Robot and Development of Python algorithms to Execute Holding, Lifting and Positioning Tasks2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The greatest feature of using a Baxter robot among other industrial robots is the ability to train this robot conveniently. The training of the robot could be done within a few minutes and it does not need so much knowledge of programming. However, this type of training feature is limited in functionality and needs frequent updating of the software and the license from the manufactural company. As the manufacturer of Baxter Robot no longer exists due to a merger, the thesis has twofold aims, (1) Exploring different functional, installation, calibration, troubleshooting and hardware features of the Baxter robot and (2) demonstrate the functionality of Baxter to perform general tasks of holding, lifting and moving of test objects from one desired position to another position using custom-made programs in Python. Owing to this, details about different software and hardware aspects of Baxter robot is presented in this thesis. Additionally, systematic laboratory tutorials are also presented in appendices for students who want to learn and operate the robot from simple to complicated tasks. In order to keep the Baxter operational for students and researchers in future, when there is no more help available from its manufacturer, this thesis endeavour to cover all these aspects. Thus, the thesis presents a brief understanding of how to use the Baxter Robot in a simple and efficient way to perform a basic industrial task. The kinematics part will show the concepts of forward and inverse kinematics and the DH (the Denavit–Hartenberg) parameters that are important to understand the end-effector position according to the world frame that will give the knowledge of those who are interested in the kinematics part of Baxter robot. The work of the thesis will make it easier to understand how to program a Baxter robot by using Python language and using the simplest way to move the arm to certain positions. The ROS principles, kinematics and Python language programs will provide a good platform to understand the usability of Baxter robot. Furthermore, easy to use laboratory tutorials are devised and are presented in the appendices. These laboratory tutorials will improve the understanding of the readers and provide a step-by-step guide of operating Baxter robot according to the principles of Robotics. In addition to all these points above, the thesis shows useful functions that are built in ROS (Robot Operating System) that make it easier to program the robot in an untraditional way which is one of a contribution of this thesis itself. The usual way to program the robots, in general, is to study the robot kinematics and calculate the position of the end-effector or the tool according to some frame or the world coordinate frame. This calculation can be done by the forward kinematics or the inverse kinematics. The set of programming Baxter robot in this thesis is not the complex calculation of the forward or the inverse kinematics. The tf (transform)tool in ROS has made it easier to reach the joint angles and program Baxter robot using Python.

  • 168.
    Andersson, Robin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Energibalansberäkning för flerbostadshus: projekterad energianvändning jämfört med beräknad energianvändning med uppmätta värden för Gävle Strand Etapp 12011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The estimated amount of energy that a building consumes during one year indicates whether it contributes to a sustainable society or not. The communal company, AB Gavlegårdarna , that rents out apartments, works not only with designing proposals for solutions for the future housing , they also work with improving their stock when it comes to energy consumption. The multi-family buildings of Gävle Strand Phase 1 were completed in 2008 with a population of twelve buildings that are shaped in four ways.

     

    During the planning phase a consultant was hired to calculate the how much energy these buildings would have to purchase and came up with an energy use of 92 kWh/m2,year. Gavlegårdarna’s own calculations are based on the actual values obtained for each apartment and in September 2009 and they showed a mean value for the whole stock, which was 114 kWh/m2,year.

     

    AB Gavlegårdarna want to find a solution to the problem and reduce the extra cost that Gävle Strand Phase 1 has given rise through increased use of energy. They want to perform precise calculations on each building's energy use. The problem can be formulated as follows:

    How much influence does the malfunction of a heat exchanger in a balanced ventilation system have on the total energy consumption in apartment buildings? Can a house among the various geometrically designed houses of a stock be considered to be representative when calculating the energy use of the stock as a whole?

    The report deals with a number of U-value and area calculations, ventilation and air leakage assessments, domestic hot water use and energy user behavior of the residents, to work out how much a simulated building uses in terms of specific energy, with unit kWh/m2,year. An building simulation program called BV2 2010was utilized.

    The results show that the majority of the buildings located in Gävle Strand Phase 1 have higher energy consumption than the consultant's basic case. This is due to several factors but the main causes of the high residential energy use is the low temperature efficiency in the FTX-system heat exchanger, the residents’ behavior and in some cases relatively high usage of hot water.

  • 169.
    Andersson, Sandra
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Fysisk aktivitets betydelse för hälsan: Hur arbetar pedagoger inom årskurs 1-3 med detta?2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Examensarbetet fokuserar på fysisk aktivitet och hälsa inom årskurs 1–3. Syftet är att belysa på vilka sätt pedagoger arbetar för att öka elevers förståelse kring fysisk aktivitets betydelse för hälsan och vilken påverkan detta har på eleverna. Urvalsgruppen är verksamma pedagoger. Undersökningen är en kvalitativ forskningsansats med semistrukturerade intervjuer som har kompletterats med ”critical incidents” observationer. Resultatet visar att pedagogerna ofta upprepar fysisk aktivitets betydelse för hälsan för att öka elevernas förståelse kring detta, genom samtal och fysiska aktivitets upplevelser. Kunskap om människokroppen anses även behövas. Slutsatser är att kroppsuppfattning - kunskap om människokroppen, förmåga att använda sin kropp och fysiska aktiviteter - är viktigt för barns förståelse om dess betydelse för hälsan. Studiens resultat ger idéer till pedagoger inom skolan om olika arbetssätt kring fysisk aktivitet för att skapa förståelse, främja hälsosamma vanor och bättre förutsättningar för lärande. Resultatet antyder att elevers totala skolprestationer förbättras av fysisk aktivitet.

  • 170.
    Andersson, Sara
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Måste vi räkna?: En (enkel) matematisk början för barn och pedagoger2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med detta examensarbete var att skapa ett matematiskt arbetsmaterial för pedagoger. Materialet ska underlätta för pedagoger som känner sig obekväma eller illa till mods vid tanken på att arbeta med matematik. Materialet, som består av handledning, arbetsmaterial och ett formulär togs fram efter att ha studerat litteratur och efter att förtester med fyra barn gjorts. Materialet är tänkt att hjälpa pedagoger att få syn på de fem grundläggande principerna hos barn som behövs för att bli bra på aritmetik. De fem principerna är ramsräkning, sifferkunskap, antalsräkning, ordinaltalsräkning och spontan antalsuppfattning. Materialet testades av tre pedagoger. Deras svar analyserades och bedömdes efter i förväg utvalda kriterier. Några kriterier uppfylldes medan andra kräver en omarbetning av materialet för att uppfyllas. Till sist togs nya kriterier fram för att kunna förbättra produkten i ett nästa skede. Examensarbetet visar att det inte behöver vara krångligt och svårt att arbeta med matematik i förskolan även om matematik kan upplevas som krångliga ekvationer, väcka obehags känslor eller upplevs kräva mycket förberdelser.

  • 171.
    Andersson Skått, Kristian
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Bergkvist, Kristoffer
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Småhusfastigheters värdeförändring vid större infrastrukturprojekt: En studie av ombyggnationen E4 Sundsvall2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Infrastructure investments is a large part of the regional development in Sweden, researchers in the subject agrees that investment in infrastructure generate increased economic development, one thing they still share a disagreement in which calculating methods are suitable. Are there any winners or losers in infrastructure projects, for example, smaller cities in the countryside where highways have previously passed, have they benefited from a quicker and easier commuting to the city, or have they been adversely affected when the highway has been given a new stretch?

    This research report focuses in one of the largest infrastructure investments in northern Sweden, European road 4 (E4) through Sundsvall. The research, combined with location-based sales comparison method and local analyzes, will show what effect market values will have on the houses real estate’s and what influence the road construction might have regarding to the values of the properties.

    The results of these studies are shown trough the average changes in property prices in the areas of Njurundabommen, Nedre Haga/Skönsberg, Nolby/Kvissleby and Västbo. However, the result was shown to have too few transactions, which is common in local level sales analyzes. This generates uncertainty in the result, meaning that the values can be large in relation to the actual sales development. The uncertainty was minimized in the results by merging two similar areas, which finally gave a result that indicates that the areas in the study had a more negative development towards Sundsvall and Sweden, since the area received a new infrastructure in the form of the E4 Sundsvall.

  • 172.
    Andersson, Tony
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Habitatval hos yngel av öring (Salmo trutta) i en undersökning i Nedre Dalälven2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this project was to examine important parameters for juvenile brown trout habitat selection in their first months after hatching. The study was carried out after approximately 30 000 fry had been released by the County Administrative Board of Gävleborg. Data on habitat selection was collected from five different localities at the river Dalälven, near Gysinge, Sweden. The method of estimating preferred habitat was to determine remaining fry after a period of seven weeks by electrofishing.

    This study confirms that the optimal local habitat choice for juvenile trout is where the substrate size 60- 200 mm is present and a hypothesis is proposed that this substrate is of importance for juvenile trout survival as it gives shelter in the presence of predators. Based on previous research the study gives some suggestions to which important habitat characteristics that were missing where no trout were recaptured.

  • 173.
    Andersson, Towe
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Lindgren, Matilda
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Fastighetsbestämning och särskild gränsutmärkning i Sverige2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to describe property definition and special boundary demarcation and to analyze the differences between the two cadastral procedures. Property boundaries, especially unlawfully determined boundaries created through unofficial parcelling, can create conflicts between landowners and make it diffi-cult to know which land that a property contains of. It is possible to clarify the boundary conditions through a property definition or through a special boundary demarcation re-establish boundary marks.

    The methods used are: (1) A literature review to collect background information, (2) A case study to summarize court cases and (3) A questionnaire study to collect opinions from cadastral surveyors.

    The result is summarized in two comparisons. Firstly between restoration of landmark and special boundary demarcation (which replaced restoration of landmark in a legislative change in 2010), which demonstrated that the change in the law is considered positive because special boundary demarcation gives a legal effect on the boundaries. Secondly between property definition and special boundary demarcation which demonstrated that the two procedures are similar to each other. One difference between the procedures is that special boundary demarcation only can be used when there are no uncertainties concerning the boundary. It also demonstrated that the cadastral procedure costs only can be distributed during property definition.

    The legal effect on the boundaries contributes with a certainty for the property owners and is also considered positive for the community development. No exact definition of what a legal uncertainty is, was found using the three methods. A definition should make it easier to know which cadastral procedure that should be used. A question to examine in future studies is the possibilities to distribute cadastral procedure costs even during special boundary demarcation. 

  • 174.
    Andersson, Victor
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Industrial economics.
    Pappersfria informationsflöden: En fallstudie om implementeringsprocessen2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Although computers have been around for a long time and are used more and more, the use of paper inoffices remains. One of the reasons is that there are not good enough digital tools to get rid of paper from work. In this qualitative case study, the office department of ABB Components is investigating on how the implementation processes for a paperless information flows can be introduced in ways that generate benefits of working digitally.

    The result of this study will be based on data collected from interviews and observations carriedout in the office. By identifying which processes using paper in the office, different tools have been developed to facilitate the implementation. The result of this study suggests that the implementation of a paperless information flows must be a well-planned change process where tools are developed to compensate for the earlier use of paper.

    With the introduction of paperless information flows, the use of consumables will decrease and the location it takes to store these papers will disappear. This leads to more cost-effective work and less waste paper. In order for this concept to lead to a more beneficial routine it needs to be redesigned for the implementation.

  • 175.
    Andersson Younas, Nikolina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    För att eleverna verkar tänka bättre när de får prata: Vilka metoder kan man hitta hos lärare som främjar diskussioner i matematik2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med arbetet är att söka reda på olika metoder lärare använder i klassrumssituationer för att stödja elevernas utveckling i matematiska uttryck gällande muntlig kommunikation mellan elever och lärare. Arbetet är baserat på observationer av tre lärare i årskurs 4, 6 och 9. Insamlad information från observationerna har resulterat i tre olika lektionsstrukturer och ett antal frågemodeller. Gemensamt i samtliga lektioner är att eleverna får först diskutera och berätta innan läraren blanda sig i; läraren har använt elevernas samtal för att bygga vidare och utgår på det sättet utifrån elevernas kunskaper. Vissa lektioner har fokus legat i diskussionen och elevers presentation av sina lösningar för klassen. I andra lektioner har läraren använt en specifik didaktisk metod för att stimulera diskussionen och elevernas förståelse. Samtliga lärare uttrycker att ett mål de haft är att eleverna skall få chansen att diskutera och ge uttryck för sina tankar verbalt.

  • 176. Andrienko, Gennady
    et al.
    Dykes, JasonJiang, BinUniversity of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    GeoViz Hamburg 2011: Linking geovisualization with spatial analysis and modeling2011Collection (editor) (Refereed)
  • 177.
    Andréasson, Frida
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Barns sätt att benämna och uppfatta geometriska former: En observation och intervjustudie med förskolebarn2010Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med arbetet är att undersöka hur barn i åldrarna tre till sex år uppfattar de geometriska formerna i sin närmiljö, utan att någon vuxen påvisar formerna. I undersökningen ingår även att se vilka former barnen känner till och hur de benämner formerna. Metoderna som använts i undersökningen är intervjuer och observationer. Huvudresultatet var att barnen såg olika geometriska former i sin förskolemiljö. Hur barnen benämnde formerna varierar mellan matematisk benämning och vardagsbenämning och även egen påhittad benämning. Att förskolorna arbetar olika med matematik gör ingen skillnad för hur barnen benämner formerna.

    Viktig Slutsats: Barnen benämner de geometriska formerna med samma benämning som de vuxna i barnens omgivning använder sig av.

  • 178.
    Andrée, Martin
    et al.
    Lantmäteriet.
    Larsson, Karolina
    KLM; Stockholms stad.
    Nordqvist Darell, Fanny
    Stockholms stad.
    Malm, Linus
    Tyréns.
    Tullberg, Odd
    WSP.
    Wallberg, Ann
    JM.
    Norsell, Johan
    NAI Svefa.
    Paasch, Jesper M.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    Paulsson, Jenny
    Kungliga Tekniska Högskolan, Stockholm.
    Slutrapport för projektet Smart planering för byggande: Delprojekt 3 - BIM som informationsstöd för 3D fastighetsbildning2018Report (Other academic)
    Abstract [sv]

    Samhällsbyggnadsprocessen behöver utvecklas och bli smartare, öppnare och mer effektiv för ett ökat bostadsbyggande. En digitalisering av samhällsbyggnadsprocessen kan ge ett effektivare samarbete mellan kommun, fastighetsägare, byggherrar, medborgare, näringsliv och myndigheter.Vid bildande av tredimensionellt avgränsade fastigheter eller fastighetsutrymmen (3D-fastigheter) behöver gränsernas läge redovisas både verbalt och i kartor och ritningar, detsamma gäller berörda rättigheter. Det är idag ofta svårt att korrekt redovisa en 3D-volym med enbart dagens pappersritningar och även svårt att läsa en registerkarta i 2D med fastigheter och rättigheter beslutade i 3D. Beslutsunderlagen i fastighetsbildnings-processen behöver bli mer enhetliga och entydiga samt fastighetsinformationen behöver bli återanvändningsbar i hela samhällsbyggnadsprocessen.I detta projekt har vi studerat informationsbehovet i de olika tidpunkterna under fastighetsbildningsprocessen för 3D-fastigheter med fokus på vem som är ansvarig för att tillhandahålla informationsunderlag för att identifiera krav på utformning av 3D-modeller (t.ex BIM) och 3D-stöd för fastighetsbildning.Internationellt finns det ett stort intresse och många frågeställningar gällande samspelet mellan BIM och Fastighetsinformation; det är däremot ganska få fall som har identifierats där man har arbetat praktiskt med BIM i relation till redovisning av 3D-fastigheter.Projektethar även tittat på behov av visualisering och tillhandahållande av fastighetsinformation i 3D, hur informationen bör utformas för att kunna tolkas korrekt samt nyttjas vidare av andra aktörer i samhällsbyggnadsprocessen.Slutsatsen i projektetär att en framtida arbetsmodell där man i samband med myndighetsutövningen för fastighetsbildning samverkar med stöd av BIM och geografisk information i ärendehandläggningen kan ge stora effekter på både myndighetens effektivitet och i ärendeutövningen och för förståelsen av fastighetbildningsbeslutet hos samtliga intressenter i processen. För att det arbete som genomförts i denna utredning skall få genomslag i den dagliga verksamheten rekommenderar vibland annatatt de statliga och kommunala lantmäterimyndigheterna arbetar vidare med att utveckla arbetsprocessen och rekommendationerna för 3D-fastighetsbildning baserat på resultatet från detta projekt och redan i dagens modell efterfrågar att man i handläggningsprocessen kan arbeta BIM-baserat även om kommande beslutshandlingar under en övergångsperiod fortfarande kommer att vara baserade på ritningsbilagor i 2D.

  • 179.
    Andrée, Martin
    et al.
    Lantmäteriet.
    Paasch, Jesper M.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Paulsson, Jenny
    Kungliga Tekniska Högskolan.
    Seipel, Stefan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Computer science.
    BIM and 3D property visualisation2018In: FIG Congress 2018: Proceedings, 2018, article id 9367Conference paper (Other academic)
    Abstract [en]

    The concept of 3D property has only existed a short period of time in Sweden, being introduced in 2004 and expanded in 2009 by the addition of condominium (apartment) ownership. It is therefore a rather new form of land management, and the demand for 3D property formation has not been as high as initially expected. There is however an increased interest in 3D property and ownership apartments today, also as being part of the nation’s geospatial infrastructure together with related 3D information for e.g. buildings, utility networks and other features. An effective management of 3D property is depending on, among other things, visualization, representation and storage of 3D real property data, such as legal boundaries and real property rights. There are at present a number of ongoing 3D development and research projects focusing on visualization and standardization of 3D cadastral boundaries. They are part of the national "Smart Built Environment" development and research program, which includes the use of BIM in the (future) 3D property formation process with focus on visualization of 3D real property and condominiums, and specification of requirements and evaluation of 3D digital real property information created and managed in the processes.

    This paper presents the preliminary results of the working group on visualization of 3D boundaries in the project "Smart planning, construction and management processes throughout the life cycle". The aim is to test the results produced in the project "Information for planning, real property formation and building permission", working group "BIM for 3D property formation." The purpose of this working group is to set the requirements for and evaluate the test bed for 3D property information. The focus is on visualization of 3D property and ownership apartments. The proposed model for digitization and visualization of 3D property formation will be tested in a test bed environment. A pilot case from the Stockholm area is then used in the test bed to see how it could work in practice.

    The expected outcome is recommendations for the exchange of documentation and other digital information in 3D processes, the visualization of legal boundaries for stakeholders, registration of legal 3D objects in the Swedish national real property register and how to communicate 3D models to right holders/stakeholders for 3D property and condominiums and the property market, as well as suggestions for a homogeneous, effective and digital flow of 3D information to be used by actors and other stakeholders in the property formation, planning and building processes.

  • 180.
    Angele, Kristian
    et al.
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Högström, Carl-Maikel
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Odemark, Ylva
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Henriksson, Mats
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Tinoco, Hernan
    Forsmarks Kraftgrupp AB, Östhammar, Sweden.
    Lindqvist, Hans
    Forsmarks Kraftgrupp AB, Östhammar, Sweden.
    Hemström, Bengt
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Flow Mixing Inside a Control-Rod Guide Tube: Part 2—Experimental Tests and CFD-Simulations2010In: 18th International Conference on Nuclear Engineering: Volume 4, Parts A and B, 2010, p. 655-663Conference paper (Refereed)
    Abstract [en]

    Alarge number of control rod cracks were detected during therefuelling outage of the twin reactors Oskarshamn 3 and Forsmark3 in the fall of 2008. The extensive damage investigationfinally lead to the restart of both reactors at theend of 2008 under the condition that further studies wouldbe conducted in order to clarify all remaining matters. Also,all control rods were inserted 14% in order to locatethe welding region of the control rod stem away fromthe thermal mixing region of the flow. Unfortunately, this measureled to new cracks a few months later due toa combination of surface finish of the new stems andthe changed flow conditions after the partial insertion of thecontrol rods. The experimental evidence reported here shows an increasein the extension of the mixing region and in theintensity of the thermal fluctuations. As a part of thecomplementary work associated with the restart of the reactors, andto verify the CFD simulations, experimental work of the flowin the annular region formed by the guide tube andcontrol rod stem was carried out. Two full-scale setups weredeveloped, one in a Plexiglass model at atmospheric conditions (inorder to be able to visualize the mixing process) andone in a steel model to allow for a highertemperature difference and heating of the control rod guide tube.The experimental results corroborate the general information obtained through CFDsimulations, namely that the mixing region between the cold crud-removalflow and warm by-pass flow is perturbed by flow structurescoming from above. The process is characterized by low frequent,high amplitude temperature fluctuations. The process is basically hydrodynamic, causedby the downward transport of flow structures originated at theupper bypass inlets. The damping thermal effects through buoyancy isof secondary importance, as also the scaling analysis shows, howevera slight damping of the temperature fluctuations can be seendue to natural convection due to a pre-heating of thecold crud-removal flow. The comparison between numerical and experimental resultsshows a rather good agreement, indicating that experiments with plantconditions are not necessary since, through the existing scaling lawsand CFD-calculations, the obtained results may be extrapolated to plantconditions. The problem of conjugate heat transfer has not yetbeen addressed experimentally since complex and difficult measurements of theheat transfer have to be carried out. This type ofmeasurements constitutes one of the main challenges to be dealtwith in the future work.

  • 181.
    Angele, Kristian
    et al.
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Odemark, Ylva
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Hemström, Bengt
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Högström, Carl-Maikel
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Henriksson, Mats
    Vattenfall Research & Development AB, Älvkarleby, Sweden.
    Tinoco, Hernan
    Forsmarks Kraftgrupp AB, Östhammar, Sweden.
    Lindqvist, Hans
    Forsmarks Kraftgrupp AB, Östhammar, Sweden.
    Flow mixing inside a control-rod guide tube: Experimental tests and CFD simulations2011In: Nuclear Engineering and Design, ISSN 0029-5493, E-ISSN 1872-759X, Vol. 241, no 12, p. 4803-4812Article in journal (Refereed)
  • 182.
    Angermann, L.
    et al.
    Institut für MathematikTechnische Universität Clausthal, Clausthal-Zellerfeld, Germany.
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Smirnov, Y. G.
    Department of Mathematics and Supercomputing, Penza State University, Penza, Russia.
    Yatsyk, V. V.
    O.Ya. Usikov Institute for Radiophysics and Electronics, National Academy of Sciences of Ukraine, Kharkiv, Ukraine.
    A nonlinear multiparameter EV problem2018In: Progress In Electromagnetics Research Symposium: PIERS 2017, PIERS 2017: Nonlinear and Inverse Problems in Electromagnetics / [ed] Beilina L., Smirnov Y., Springer New York LLC , 2018, p. 55-70Conference paper (Refereed)
    Abstract [en]

    We investigate a generalization of one-parameter eigenvalue problems arising in the theory of wave propagation in waveguides filled with nonlinear media to more general nonlinear multi-parameter eigenvalue problems for a nonlinear operator. Using an integral equation approach, we derive functional dispersion equations (DEs) whose roots yield the desired eigenvalues. The existence of the roots of DEs is proved and their distribution is described.

  • 183.
    Angermann, Lutz
    et al.
    Clausthal University of Technology, Clausthal, Germany..
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Yatsyk, Vasyl
    O. Ya, Usikov Institute for Radiophysics and Electronics of the National Academy of Sciences of Ukraine, Kharkiv, Ukraine.
    Mathematical models for scattering and generation of plane wave packets on layered cubically polarisable structures2013In: Far East Journal of Applied Mathematics, ISSN 0972-0960, Vol. 81, no 1-2, p. 1-31Article in journal (Refereed)
    Abstract [en]

    The paper deals with different formulations of mathematical models for the analysis of processes of resonance scattering and generation of plane wave packets on isotropic, nonmagnetic, linearly polarised media with a nonlinear, layered dielectric structure of cubic polarisability. For each formulation, sufficient conditions for the existence and, partially, uniqueness of the corresponding solution are derived.

  • 184.
    Angermann, Lutz
    et al.
    Technische Universität Clausthal, Institut für Mathematik, Clausthal-Zellerfeld, Germany .
    Shestopalov, Yury V.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Mathematics.
    Yatsyk, Vasyl V.
    O.Ya. Usikov Institute for Radiophysics and Electronics of the National Academy of Sciences of Ukraine, Kharkiv, Ukraine .
    Eigenmodes of linearised problems of scattering and generation of oscillations on cubically polarisable layers2015In: Inverse Problems and Applications / [ed] Larisa Beilina, Springer-Verlag New York, 2015, Vol. 120, p. 67-80Conference paper (Refereed)
    Abstract [en]

    In the frequency domain, the resonant properties of nonlinear structures are determined by the proximity of the scattering/generation frequencies of the nonlinear structures to the complex eigenfrequencies of the corresponding homogeneous linear spectral problems with the induced nonlinear permeability of the medium. Here the case of cubically polarisable, canalising, and decanalising layers is considered.

  • 185.
    Ansin, Frida
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Rödin, Matilda
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Exploateringsavtal: Samverkan mellan kommun, lantmäterimyndighet och exploatör2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    On January 1st 2015 an amendment passed in the Planning and Building Act in order to simplify and rationalize the detailed development plan process. The amendment includes a new part for cadastral authority in the plan process and new rules for development agreement. The municipalities should adopt guidelines for these agreements. The aim of this study was to describe how the collaboration between municipality, cadastral authority and developer works when it comes to development agreement and how the amendment in the Planning and Building Act concerning the development agreement has affected these participants.

    To answer the thesis a web survey was sent to all municipalities in Sweden to get an overview of how the amendment has influenced the country. Semi-structured telephone interviews were also performed in five municipalities that have adopted guidelines for the development agreements. The interviews were performed with land development engineers, cadastral supervisors and developers to receive their perspective of the collaboration and how the amendment has affected them.

    The results of the study have shown that negotiations have started earlier between municipalities and developers after the amendment in the Planning and Building Act passed. The municipalities also need to pay compensation when they take land for public places after the amendment. The cadastral authority’s more active part has contributed to assure that ambiguities and shortcomings might be solved in the development agreement. However, it is still too early to tell what the cadastral authorities part has contributed in the development agreements. The developer has got a major opportunity to influence the development agreements. The collaboration between municipalities, cadastral authorities and developers has become clearer and improved but overall it is unchanged. There are opportunities for improvement in the long term.

  • 186.
    Antoniou, Nestoras
    et al.
    Department of Civil and Environmental Engineering, University of Cyprus, Nicosia, Cyprus; Department of the Built Environment, Eindhoven University of Technology, Eindhoven, The Netherlands.
    Montazeri, Hamid
    Department of the Built Environment, Eindhoven University of Technology, Eindhoven, The Netherlands; Department of Civil Engineering, KU Leuven, Leuven, Belgium.
    Wigö, Hans
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Neophytou, Marina
    Department of Civil and Environmental Engineering, University of Cyprus, Nicosia, Cyprus.
    Blocken, Bert
    Department of the Built Environment, Eindhoven University of Technology, Eindhoven, The Netherlands; Department of Civil Engineering, KU Leuven, Leuven, Belgium.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    CFD and wind-tunnel analysis of outdoor ventilation in a real compact heterogeneous urban area: evaluation using “air delay”2017In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 126, p. 355-372Article in journal (Refereed)
    Abstract [en]

    Outdoor urban ventilation in a real complex urban area is investigated by introducing a new ventilation indicator – the "air delay". Computational Fluid Dynamics (CFD) simulations are performed using the 3D steady Reynolds-Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) approaches. The up-to-date literature shows the lack of detailed evaluations of the two approaches for real compact urban areas. This study further presents a systematic evaluation of steady RANS and LES for the assessment of the ventilation conditions in a dense district in Nicosia, Cyprus. The ventilation conditions within the urban area are investigated by calculating the distribution of the age of air. To better assess the outdoor ventilation, a new indicator, the "air delay" is introduced as the difference between the local mean age of air at an urban area and that in an empty domain with the same computational settings, allowing the comparison of the results in different parts of the domain, without impact of the boundary conditions. CFD results are validated using wind-tunnel measurements of mean wind speed and turbulence intensity performed for the same urban area. The results show that LES can accurately predict the mean wind speed and turbulence intensity with the average deviations of about 6% and 14%, respectively, from the wind-tunnel measurements while for the steady RANS, these are 8% and 31%, respectively. The steady RANS simulations overestimate the local mean air delay. The deviation between the two approaches is 52% at pedestrian level (2 m).

  • 187.
    Apelgårdh Svedlund, Malin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Kan aktivitetskort underlätta utomhusvistelsen i skogen för förskolebarn i åldern två till tre år?2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 188.
    Apell, Oscar
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Energikartläggning av Fridhemsskolan 16:22014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Increased energy consumption in the world has created an increased supply of various fuels, especially fossil fuels. The Swedish government has set up various energy targets for 2020. To reach these goals it’s important to increase the energy efficiency in local buildings such as schools. This work illustrates the breakdown between energy supply and energy losses over the school. It also shows various suggestions to reduce the energy usage. The results shows that energy losses from transmission is definitely the greatest. Significant savings can be made by replacing windows, add insulation and install motion sensor lightning. If the proposed savings would be made, the energy consumption of the school could decrease by approximately 165MWh/year. This represent an annual saving of about 123600 SEK.

  • 189.
    Apicella Fernandez, Sergio
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Surface energy modification of metal oxide to enhance electron injection in light-emitting devices: charge balance in hybrid OLEDs and OLETs2017Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Organic semiconductors (OSCs) present an electron mobility lower by several orders of magnitude than the hole mobility, giving rise to an electron-hole charge imbalance in organic devices such as organic light-emitting diodes (OLEDs) and organic light-emitting transistors (OLETs). In this thesis project, I tried to achieve an efficient electron transport and injection properties in opto-electronic devices, using inorganic n-type metal oxides (MOs) instead of organic n-type materials and a polyethyleneimine ethoxylated (PEIE) thin layer as electron transport (ETLs) and injection layers (EILs), respectively. In the first part of this thesis, inverted OLEDs were fabricated in order to study the effect of the PEIE layer in-between ZnO and two different emissive layers (EMLs): poly(9,9-dioctylfluorene-alt-benzothiadiazole) polymer (F8BT) and tris(8-hydroxyquinolinato) aluminum small molecule (Alq3), based on a solution and thermal evaporation processes, respectively. Different concentrations (0.80 %, 0.40 %) of PEIE layers were used to further study electron injection capability in OLEDs. After a series of optimizations in the fabrication process, the opto-electrical characterization showed high-performance of devices. The inverted OLEDs reported a maximum luminance over 104 cd m-2 and a maximum external quantum efficiency (EQE) around 1.11 %. The results were attributed to the additional PEIE layer which provided a good electron injection from MOs into EMLs. In the last part of the thesis, OLETs were fabricated and discussed by directly transferring the energy modification layer from OLEDs to OLETs. As metal oxide layer, ZnO:N was employed for OLETs since ZnO:N-based thin film transistors (TFTs) showed better performance than ZnO-based TFTs. Finally, due to their short life-time, OLETs were characterized electrically but not optically.

  • 190.
    Apicella Fernández, Sergio
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    MEASUREMENT OF DIELECTRIC CONSTANT FOR WATER AND ITS TEMPERATURE DEPENDENCE AT 0 AND 86ºC2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The dielectric properties determine the electrical characteristics of materials. These properties are important for understanding the behavior of materials and how they can interact with each other. Engineers and scientists need to measure these parameters as accurately as possible, and thus be able to integrate them in their designs in a reliably way.

     

    Examples of application are dielectrics used in capacitors that have the function of reducing the applied electric field and increase the capacitors´ capacitance. The later can be increased by using dielectrics with high permittivity (dielectric constant) as water which has a dielectric constant of 80 at room temperature (25ºC). Unfortunately water cannot be used alone as dielectric due its capacity to be conductive and has to be combined with other materials.

    However, this study will focus only on measuring the dielectric properties of water and its temperature dependence. Temperatures chosen for measurements are 0 and 86ºC.

     

    Several methods have been studied over the years to measure the dielectric properties of materials, but there are only three possible measurement methods for liquids: coaxial probe, parallel plates and free space method. Comparing the three methods, in our case the free-space method is better because it allows to perform measurements at high temperatures and in hostile environments. These two features are very important, since the water should be measured at 86 ºC and measurements are performed in a RF (Radio Frequency) lab, where interferences due to the electronic devices can affect accuracy in free-space measurements.

     

    Hence, the following thesis is based exclusively on analyzing the free-space measurement method for measuring the reflection parameters in dB by using two horn antennas. Both antennas are connected to the Vector Network Analyzer (VNA): one as transmitter and the other as receiver. Reflection parameters are also calculated by introducing the reflection formula for lossless material and a finite length in Matlab. Then, the dielectric constant is extracted by comparing both reflections in dB. 

  • 191.
    Appel, Madeleine
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Kulturarvets mosaiklandskap i ny tappning för trädgårdar och balkonger: En litteraturstudie med designförslag som bidrag för bevarandet av mångfalden för solitära bins överlevnad2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract. The purpose of this study is to find out what can be done in gardens and balconies for solitary bees survival, species have already been lost or are red-listed because of poor conditions in terms of habitat. What can design-proposals look like for gardens and balconies? What do suitable habitats contain and what do threats look like for solitary bees?The goal with this literature study was to find answers to my questions. Based on facts that emerged from the results, design proposals have been made for gardens and balconies. Increased biotope-surface from ancient times mosaic-landscape can in modern environments like gardens and balconies be designed as non-toxic and flower-rich meadows, flowering border zones, ditches and flower beds, potted plants, flowering trees and shrubs. Solitary bees need shelter, water to drink and food to eat as in nectar and pollen-rich plants. They need flowering plants from early spring to late autumn to survive. It´s important to spread knowledge and understanding how solitary bees live their lives, that people can cooperate to achieve long-term sustainable habitat solutions. Solitary bees need many flowering plant-surfaces that can act as dispersal corridors in to urban environments, where every single square meter flowering-surface is of importance. Solitary bees increase in number with increasing biotope-surfaces which are facts that design proposals are based on. Devastating threats for solitary bees are floral shortage in urban areas, spraying with various poisons, domestic bees spreading diseases, human fear of small insects and altered habitats.

  • 192.
    Arcos Usero, Lucía
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Analysis and improvements of outdoor hot benches in Gävle2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Five exterior hot benches have been installed in Gävle, in Kyrkogatan street by the company Gävle Energi with the aim of achieving the wellnes of people that sit on them. This system uses the residual heat from the district heating, representing consequently a non-polluting system. However, the temperature desired on the surface, 35°C is not always achieved before different exterior conditions. For this reason, Gävle Energi is interested in carrying out a study about enhancements that could be made in the system in order to take them into account for future projects of this kind of technology.

     

    The aim of this project is analysing if it would be possible to achieve the requirements established by Gävle Energi, changing with this objective all the necessary system parameters of the current system such as diameter of the pipes, materials, number of turns... These requirements consist of working with a supply temperature of 40, 45 and 50°C when the exterior conditions are 0, -5 and -10°C respectively, accomplishing always 35°C on the surface. Moreover, in case that it was not possible, providing the company with the characteristics of the system that would make the system as efficient as possible, specifying for different exterior temperatures the mass flow, pressure drop, velocity and needed power.

     

    The study has been developed by different simulations with the software COMSOL, whose use requires a high knowledge on heat transfer. After several simulations, it has been checked that it is not possible to accomplish the requirements established by the company. However, a new more efficient design has been designed because the supply temperatures of the system to accomplish an average temperature of around 35°C on the surface have been minimised. For that, several changes have been carried out. The number of pipes turns have been increased from 12 to 17, their total diameter from 20mm to 30mm and the distance between the centres of the pipes from 5.5cm to 4cm. The 2mm of outer plastic thickness of the pipes has been replaced by copper and the height of the pipes has been moved 2cm upwards.

     

    With all these changes, the final length of the pipes inner the stones has a value of 40.6m and the supply temperatures reach 46, 47 and 49°C for the 0,-5 and -10°C exterior conditions respectively. Apart from the supply temperatures for the study cases, the ones necessary to accomplish always the temperature desired on the surface for other exterior temperatures have been provided together with the amount of power necessary, velocity flow, volumetric flow and pressure drop for all the different cases. These values would allow the company to work always at the optimum point as well as to design the heat pump for the system.

  • 193.
    Ares Gondra, Zaloa
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Study of factors influcencing the quality and yield of biodiesel produced by transesterification of vegetable oils2009Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Biofuels are a developing kind of fuel whose origin is biomass. Among them, many different kind of fuels can be found: bioethanol, biobutanol, biodiesel, vegetable oils, biomethanol, pyrolysis oils, biogas, and biohydrogen. This thesis work is focused on the production of biodiesel, which can be used in diesel engines as a substitute for mineral diesel. Biodiesel is obtained from different kinds of oils, both from vegetable and animal sources. However, vegetable oils are preferred because they tend to be liquid at room temperature.

    The process to obtain biodiesel implies first a reaction between the oil and an alcohol, using a catalyst and then a sedimentation, where the biodiesel and the glycerol, the two products that are obtained, can be separated because of their difference in density. After the separation, raw biodiesel is obtained and a treatment with either water bubbling or dry cleaning products is needed to obtain the product which will be ready to use.

    Many methods are available for the production of biodiesel, most of them require heat for the transesterification reaction, which converts the oil into biodiesel. Apart from that, in many cases biodiesel is produced by big companies or by individuals but using complicated and expensive installations.

    This work is an attempt to develop a way of producing biodiesel without any use of external heat, using a simple procedure which could be used by people with a low knowledge of chemistry or chemical processes. It also seeks to set an example on how biodiesel can be easily made by oneself without the use of any industrial systems, with a low budget and limited need of supervision over the process.

    In order to achieve that, many trials were undertaken, introducing changes in the different parameters that are responsible for the changes in the final product. Among them, changes in the amount and type of catalyst, the way the catalyst is added, the type of oil used, the time of reaction and the temperature were made. Apart from that, different types of cleaning were tried, starting by water cleaning and then using powder type products, Magnesol, D-Sol and Aerogel. A centrifuge was also tried to test its utility when separating impurities from liquids or different liquid phases. The results of the different trials were analysed using various tests, the most important being the 3:27 test, the solubility test, the soap titration and pH measurements.

    To sum up, it could be said that the investigation was a success, since it was proved that biodiesel can be made without the use of any external heat with both alkali and acid catalysts, as well as with different ways of adding the catalyst. As for the cleaning, good results were obtained with both dry products and water cleaning, since the soap content of the biodiesel was reduced in both cases. Apart from that, the centrifuge proved to be valid to eliminate impurities from raw oil.

  • 194.
    Arfan, Muhammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science. 202100-2890.
    Biogas Value Chain in Gävleborg: Feedstock, Production and Use2019Report (Other academic)
    Abstract [en]

    This report aims to identify the current status and future opportunities for biogas as an alternative fuel for road transport in the Gävleborg region. The regional actors along the value chain are mapped by their role in feedstock supply, production and use of the biogas. Mapping and analysis of biogas development generally in Sweden and particularly in the Gävleborg region has been conducted primarily through literature, national and regional statistics and through interviews with the regional actors. About 15 companies were reached through emails and phone calls during the interview process.

    In 2017, about 3.5-4.0 million Nm3 of raw biogas (50-65% CH4) was produced in the region of which 3.6 GWh was upgraded. The region has two plants with upgrading facilities, one in Forsbacka, which produces gas mainly from food waste and Duvbacken, the wastewater treatment plant in Gävle. The gas produced at these two big facilities is upgraded and mostly used as transport fuel in the region, and for the industry. Gas produced from other sources is either used for heat and electricity production or flared to avoid methane emissions to the environment. The region has 14 buses and more than 500 other vehicles running on biogas. The gas infrastructure is not well developed in the region except for two filling stations situated in Gävle and Forsbacka. However, some developments on building biogas infrastructure for transport are in process.

    Analysis of interviews with actors and literature studies revealed that the region has much more feedstock for biogas production than used in the currently installed capacity of biogas technologies. Many actors showed great interest in its use as transport fuel but had very serious concerns about its future scope. Lack of supporting infrastructure such as filling stations, very low market demand and regional long-term strategies on biogas as transport fuel are considered barriers in the sector´s further development in the region. The value chain actors need to work more closely to get the most out of this valuable resource. Additionally, future planning on biogas should also consider its other uses such as an energy source for manufacturing industry, shipping and as raw material for chemicals or intermediate products.

  • 195.
    Arfwidsson, Linnéa
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Warg, Alicia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Traditionella och nya upplåtelseformer av bostadslägenheter2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This essays main focus is to further develop the understanding and describe six different types of tenure. The essay investigate similarities and differences between the types of tenure on the Stockholm housing market. The most common types of leaseholds, ownership apartments, and rental apartments will be described but and also new types of leases will be described. Such as cooperative rental apartments, condominiums, low purchase price apartments and rental purchases. The latter two are new forms of types of ownership and have emerged as an attempt by developers to bring young adults and low-wage earners into the housing market.

    Firstly, The qQuestion formulations in this essay are constructed to investigate similarities and differences which exist between the different forms of submission. Secondly, the questions target what kind of current costs for housing and the non-recurrent costs for purchasing. Finally, the purposes for the introduction of the new forms of leasing.

    The study has been conducted through literature studies and also interviews with market developers. Therefore, based on the study questions, respondents have answered the basis for our presentation and discussion of a descriptive analysis of the various forms of submission.

    Based on the results of the study, it can be clarified that the rental apartments can be the most advantageous in terms of the cost. But then it is taken into account that the queue is about 10 years for getting an apartment. Further, the results indicate that individuals that has a capital and the opportunity to purchase a ownership apart, the queue isn’t a matter and the individual has an opportunity to make a profit or loss on a later sale of the residence. Taking account to amortization of loans, an ownership apartment can be most advantageous from an economic perspective. Condominiums has been found to have a relatively low fee but the monthly cost become relatively high depending on the high purchase price.

    The results of this study shows that co-operative rental apartments have been found to have a low monthly cost. But the problem is that they are bothered by a long queue and also that the individual is dependent of a input gains. The two new types of low purchase price apartments and rental purchases on the market are so newly established which makes it difficult to make an accurately interpret of their impact on the housing market today.

  • 196.
    Arghand, Taha
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Human subjective response to combined radiant and convective cooling by chilled ceiling combined with localized chilled beam2015Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    The aim of the present research is to identify human subjective response (health and comfort) to the micro-thermal environment established by integration of individually controlled localized chilled beam and chilled ceiling (LCBCC) system and to compare its performance with the performance of mixing ventilation combined with chilled ceiling (CCMV).Experiments were carried out in mock-up of an office (4.1 m × 4.0 m × 3.1 m, L× W× H) with one person under two summer temperature conditions (26 °C and 28 °C). To mimic direct solar radiation in the room, five radiative panels on the wall together with electrical sheets on the half of the floor were used. The test room was set-up with two desks, as two workstations, and one laptop on each table. The main workstation (WS1) was located close to the simulated window. The second work station (WS2) was placed in the opposite side of the room. The room was equipped with two types of ventilating and cooling systems.  The first system consisted of a localized active chilled beam (LCB) unit together with chilled ceiling (CC) panels. The LCB was installed above the WS1 to create micro-environment around the occupant sitting at the desk. The supply flow rate from the LCB could be adjusted by the occupant within the range of 10 L/s to 13 L/s by means of a desk-mounted knob. The integration of mixing ventilation (MV) system and chilled ceiling panels was the second ventilating and cooling strategy. Twenty- four subjects (12 female and 12 male) were exposed to different indoor environment established by two cooling systems. Each experiment session lasted 120 min and consisted of 30 min acclimatization period and 90 min exposure period. The performance of the systems was identified and compared by physical measurements of the generated environment and the response of the human subjects.

    The study showed that perceived air quality (PAQ), overall thermal sensation (OTS) acceptability and local thermal sensation (LTS) acceptability clearly improved inside the micro-environment by using LCBCC system. Moreover, at the main workstation, OTS and LTS votes were close to “neutral” thermal sensation (ASHRAE seven point scale) when LCBCC system was used. However, OTS and LTS votes increased to the “slightly warm” side of the scale by applying CCMV system which implied the better cooling performance of the LCBCC system. Acceptability of work environment apparently increased under the room condition generated by LCBCC system.

    In agreement with human subjective study, the results from physical measurements and thermal manikin study showed that uniform thermal condition was generated all over the room. Air and operative temperature distribution was almost uniform with no difference higher than 1 °C between the measured locations in the room. Thus, both LCBCC and CCMV systems performed equally well outside of the micro-environment region. The use of the chilled ceiling had impact on the airflow interaction in the room and changed the airflow pattern. It can be concluded that the combination of convective and radiative systems can be considered as an efficient strategy to generate acceptable thermal condition in rooms.

  • 197.
    Arghand, Taha
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Karimipanah, Taghi
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Awbi, Hazim
    School of Construction Management and Engineering, University of Reading, United Kingdom.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Larsson, Ulf
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Linden, Elisabet
    University of Gävle, Faculty of Engineering and Sustainable Development, BMG laboratory.
    An experimental investigation of the flow and comfort parameters for under-floor, confluent jets and mixing ventilation systems in an open-plan office2015In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 92, p. 48-60Article in journal (Refereed)
    Abstract [en]

    There is a new trend to convert the workplaces from individual office rooms to open offices for motivating money saving and better communication. With such a shift the ability of existing ventilation systems in meeting the new requirements is a challenging question for researchers. The available options could have an impact on workers' health in terms of providing acceptable levels of thermalcomfort and indoor air quality. Thus, this experimental investigation focuses on the performances of three different air distribution systems in an open-plan office space. The investigated systems were: mixing ventilation with ceiling-mounted inlets, confluent jets ventilation and underfloor air distribution with straight and curved vanes. Although this represents a small part of our more extensiveexperimental investigation, the results show that all the purposed stratified ventilation systems (CJV and UFAD) were more or less behaving as mixing systems with some tendency for displacement effects. Nevertheless, it is known that the mixing systems have a stable flow pattern but has the disadvantage of mixing contaminated air with the fresh supplied air which may produce lower performance and in worst cases occupants' illness. For the open-plan office we studied here, it will be shown that the new systems are capable of performing better than the conventional mixing systems. As expected, the higher air exchange efficiency in combination with lower local mean age of air for corner-mounted CJV and floor-mounted UFAD grills systems indicates that these systems are suitable for open-plan offices and are to be favored over conventional mixing systems.

  • 198.
    Arizcun Zúñiga, Paula María
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Ram pump hydraulic air test. Pressure conditions and flow measurements: Experimental research and case study2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study consists of the development of a ram pump, which will allow the pumping of water without the need of external energy sources. It is considered an analysis of interest since, once it is finished; it can be applied in reality improving and facilitating different activities related to agriculture and health.

    Previous studies have been made related to the ram pump; however, in this case, it is intended to understand the system that has been built in the laboratory in order to find the best combination of parameters that will lead to obtain the highest possible efficiency. 

    The study will be carried out by studying scientific literature and by experimenting in the laboratory. Encompassing the experimental and literary field, it is expected to understand perfectly the advantages and disadvantages of the ram pump in order to determine if it is worth it to install in certain places.

    After the study, the most favourable parameters for the operation of the Bruzaholms Bruk pump have been obtained. It has been found that the use of a longer drive pipe favours the operation of the system, as it is possible to obtain a higher efficiency, although it must be taken into account that the mentioned length needs to be controlled, as it could reduce the working rhythm of the pump. It has also been seen that the pump gives better results if the impulse valve is completely opened. Finally, it has been proven that, as long as the height difference between the two tanks is enough, increasing the height of the water source will favour the operation of the system.

  • 199.
    Arnaiz Remiro, Lierni
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Modelling and assessment of energy performance with IDA ICE for a 1960's Mid-Sweden multi-family apartment block house2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The present thesis has been carried out during the spring of 2017 on behalf of Gavlegårdarna AB. This is a public housing company in Gävle (Sweden) which is a large energy consumer, over 200 million SEK per year, and has the ambitious goal of reduce its energy consumption by 20 % between 2009 and 2020. Many multi-family apartment blocks were built during the "million programme" in the 60’s and 70’s when thermal comfort was the priority and not the energy saving. Nevertheless, this perspective has changed and old buildings from that time have been retrofitted lately, but there are many left still. In fact, one of these buildings will be retrofitted in the near future so a valid model is needed to study the energy saving measures to be taken. The aim of this thesis is to get through a calibration process to obtain a reliable and valid model in the building simulation program IDA ICE 4.7.1. Once this has been achieved it will be possible to carry out the building’s energy performance assessment. IDA ICE has shown some limitations in terms of thermal bridges which has accounted for almost 15 % of total transmission heat losses. For this reason, it is important to make a detailed evaluation of certain joints between elements for which heat losses are abundant. COMSOL Multiphysics® finite element software has been used to calculate these transmittances and then use them as input to IDA ICE to carry out the simulation.

    Through an evidence-based methodology, although with some sources of uncertainty, such as, occupants’ behaviour and air infiltration, a valid model has been obtained getting almost the same energy use for space heating than actual consumption with an error of 4% (Once the standard value of 4 kWh/m2 for the estimation of energy use in apartments' airing has been added). The following two values have been introduced to IDA ICE: household electricity and the energy required for heating the measured volume of tap water from 5 °C to 55 °C. Assuming a 16 % of heat losses in the domestic hot water circuit, which means that part of the heat coming from hot water heats up the building. This results in a lower energy supply for heating than the demanded value from IDA ICE. Main heat losses have been through transmission and infiltration or openings. Windows account 11.4 % of the building's envelope, thus the losses through the windows has supposed more than 50 % of the total transmission losses. Regarding thermal comfort, the simulation shows an average Predicted Percentage of Dissatisfied (PPD) of 12 % in the worst apartment. However, the actual value could be considerably lower since the act of airing the apartments has not been taken into account in the simulation as well as the strong sun's irradiation in summer which can be avoided by windows shading. So, it could be considered an acceptable level of discomfort. To meet the National Board of Housing Building and Planning, (Boverket) requirements for new or rehabilitated buildings, several measures should be taken to improve the average thermal transmittance and reduce the specific energy use. Among the energy saving measures it might be interesting replace the windows to 3 pane glazing, improve the ventilation system to heat recovery unit, seal the joints and intersections where thermal bridges might be or add more insulation in the building’s envelope.

  • 200. Arnemo, Ulf
    et al.
    Bengtsson, Lars
    University of Gävle, Center for Logistics and Innovative Production. University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology, Occupational Health Science. University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Management, Industrial Design and Mechanical Engineering, Industrial Management.
    Berggren, Christian
    Linköpings universitet.
    Hansson, Stefan
    Holmberg, Gunnar
    Karabag, Solmaz Filiz
    Karlsson, Mats
    Larsson, Bengt
    Rencrantz, Daniel
    Sigfridsson, Erik
    Stefan, Ioana
    University of Gävle, Center for Logistics and Innovative Production.
    Wang, Wiehong
    Rapid innovators in emerging economies: Challenges and opportunities for Swedish firms2016Report (Other academic)
1234567 151 - 200 of 4067
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf