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  • Bauer, Tobias
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Andersson, Joel B.H.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kampmann, Tobias Christoph
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Analysis of data from Unmanned Aerial Systems (UAS) in a Virtual Reality environment2019In: Proceedings of the Visual3D conference / [ed] Tobias C. Kampmann, 2019, p. 19-19Conference paper (Refereed)
    Abstract [en]

    The use of Unmanned Aerial Systems (UAS) is getting increasingly popular for many different types of applications. The field of geology is slowly catching up resulting in new and innovative UAS solutions for various kinds of airborne measurement techniques. These techniques comprise a wide range of geophysical and remote sensing methods used to investigate the sub-surface. At Luleå University of Technology two different types of UAS are used in combination with a Virtual Reality environment in order to analyze geological structures and related ore deposits and mineralizations. The two UAS comprise a) a custom made quadrocopter (HUGIN) with a pay load of approx. 3.5 kg and an operational time of 5 times (batteries) maximum 35 minutes depending on payload, ambient temperatures and wind speed; and b) a foldable DJI Mavic Pro with an operational time of 3 times 30 minutes. The HUGIN system can be operated with a high-resolution optical camera for photogrammetry surveys and a 3-axial fluxgate magnetometer for measuring magnetic anomalies within bedrock and ultimately delineating geological structures. The system is highly flexible and a thermal camera is currently added to the system in order detect water fluxes in relation to geological structures or exothermal mineral processes. The DJI system is equipped with an optical camera for photogrammetric surveying and is a highly valuable tool in remote areas due to its lightweight and compact construction.Data acquired from both UAS is subsequently analysed in a Virtual Reality lab utilizing a 6m wide screen with active stereo functions. Photogrammetry data is first processed using the Aigsoft software package following a Structure for Motion (SfM) workflow where dense point cloud models and subsequently meshed and textured 3D surface models are produced. These models are then converted and transferred to the GeoVisionary software package that allows visualization of models in stereo 3D view. This allows digitizing geological structures such as foliation, fractures, and faults among others in an immersive 3D environment and provides an efficient tool complimentary to traditional field mapping. In particular, this makes it possible to capture and analyse data from hardly accessible and dangerous areas such as rock faces in open pits. Another complimentary method of data analysis comprises SCAT analysis of the meshed surfaces using the MOVE software package.

  • Kampmann, Tobias Christoph
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bauer, Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The benefits of organized networking and matchmaking for the development of 3D/4D geomodel visualization2019In: Proceedings of the Visual3D conference 2019, 1–2 October, Uppsala, Sweden. Luleå University of Technology, 60 pages.: Visualization of 3D/4D models in geosciences, exploration and mining / [ed] Tobias C. Kampmann, Luleå, Sweden: Luleå University of Technology, 2019, p. 43-43Conference paper (Refereed)
    Abstract [en]

    While huge territory of the EU shows a very high exploration potential and many EU countries remain attractive to investors (e.g. Fraser Institute, 2015), a mere 4% of global exploration expenditure is currently invested within European countries. One tool to trigger a higher degree of investment in exploration and to secure the domestic supply of both main commodities and critical raw materials (CRM) is to enhance our three-dimensional geometric understanding of the Earth’s crust.For these reasons, EIT Raw Materials decided to fund the Visual3D network of infrastructure (NoI) for three years (2017–2019). Visual3D involves to-date 14 partner organisations from nine EU countries. The NoI aims to integrate expertise within exploration and 3D modelling from industry, academia and research institutes, with the ambition to increase the understanding of geological bodies in 3D and 4D through improved visualisation techniques. The network believes firmly that the integration of novel visualization technologies (e.g. virtual and augmented reality) into workflows of exploration, mining and geoscientific research will bring a much-needed innovation boost to the European raw materials sector and increase its competitiveness.During its first year, Visual3D has compiled the network expertise and infrastructure regarding visualization tools available at the partner facilities. An overview of this infrastructure, as well as projects conducted by network partners is available on the Visual3D homepage (www.visual3d.info). The network also managed to identify common issues in the field of geomodelling, the solutions to which may be facilitated by a pan-European network approach, such as data compatibility, communication of geomodels, as well as complexity and variety of software. Subsequent years have been dedicated to the conceptualization of possible projects in order to solve the issues name above, as well as matchmaking to find expert consortia for these projects.So far, four workshops including project partners and invited external stakeholders have been held. Networking and matchmaking during these workshops has resulted in successful project proposals in the EIT RawMaterials KAVA calls for educational (MireBooks), as well as upscaling projects (FARMIN). Both these projects are presented at the Visual3D conference 2019. Further project ideas have been discussed within Visual3D and will be developed further.The benefits of organized networking in novel research and developments fields, such as visualization of 3D/4D models for exploration and geosciences, has become apparent during the lifetime of the Visual3D network. The network partners would encourage pan-European funding institutions such as EIT RawMaterials to provide continuous funding to similar networking initiatives, especially in highly innovative and novel research fields. Well-organized communication between different stakeholders is the basis of technological innovation and has the potential to give the European raw materials sector the leading edge in this highly competitive global market.

  • Torres, Cynthia M.
    et al.
    Departamento de Ingeniería Metalúrgica y Minas, Universidad Católica del Norte, Antofagasta, Chile. Centro Integrado de Pilotaje de Tecnologías Mineras, CIPTEMIN, Antofagasta 124000, Chile..
    Ghorbani, Yousef
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Hernández, Pía C.
    Departamento de Ingeniería Química y Procesos de Minerales, Universidad de Antofagasta,Antofagasta, Chile.
    Justel, Francisca J.
    Departamento de Ingeniería Metalúrgica y Minas, Universidad Católica del Norte, Antofagasta, Chile. Departamento de Ingeniería Química y Procesos de Minerales, Universidad de Antofagasta,Antofagasta, Chile..
    Aravena, Matías I.
    Departamento de Ingeniería Metalúrgica y Minas, Universidad Católica del Norte, Antofagasta, Chile.
    Herreros, Osvaldo O.
    Departamento de Ingeniería en Minas, Universidad de Antofagasta, Antofagasta, Chile.
    Cupric and Chloride Ions: Leaching of ChalcopyriteConcentrate with Low Chloride Concentration Media2019In: Minerals, ISSN 2075-163X, E-ISSN 2075-163X, Vol. 9, no 10, article id 639Article in journal (Refereed)
    Abstract [en]

    In this paper, the effect of the cupric and chloride ions concentrations on copper dissolution from chalcopyrite concentrate was studied in acidified media. Variables included three different concentrations of Cu2+ (0.5, 1.5, and 2.5 g L−1), four different concentrations of Cl (0, 5, 7, and 10 g L−1), two different pH values of 1 and 2, and a constant temperature of 60 °C. Results indicated that addition of Cl to the system improves copper extractions, especially at higher concentrations of Cu2+. Initial copper concentrations in the leaching solution did not significantly affect the copper extraction when Cl was not present. Better copper extractions were obtained at pH 1 as compared with pH 2. As the Cu2+ and Cl concentrations were increased, higher values of redox potential were obtained. According to the formation constants of the chloro-complexes, the predominant species in the Cu2+/Cl system in the studied interval were CuCl+ and Cu2+. Using a model of copper speciation in the experimental range predicted for a single copper concentration with increasing Cl concentration, the Cu2+ concentration decreased significantly while the concentration of the chloro-complex species CuCl+ increased. In the leached residue, evidence of sulfur formation was found using SEM and corroborated by XRD analysis. When chloride is present in the medium, the amounts of copper and iron in the residue decrease, confirming a positive effect of chloride on the extraction of copper from concentrate for the studied conditions.

  • Garcia Uriarte, Ainara
    et al.
    TECNALIA Research & Innovation.
    Menger, Pierre
    TECNALIA Research & Innovation.
    Garcia Zambrano, Laura
    TECNALIA Research & Innovation.
    Alonso Galdames, Aritz
    TECNALIA Research & Innovation.
    Kampmann, Tobias Christoph
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bark, Glenn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Alvarenga, Rodrigo A.F.
    Ghent University, Belgium.
    Dewulf, Jo
    Ghent University, Belgium.
    Sanjuan-Delmás, David
    Ghent University, Belgium.
    Drielsma, Johannes
    European Association of Mining Industries, Metal Ores & Industrial Minerals (Euromines).
    Lindblom, Mats
    Boliden Mineral AB, Sweden.
    Alcon, Lucas
    Cobre las Cruces, S.A., Spain.
    Escobar Torres, Juan Manuel
    Cobre las Cruces, S.A., Spain.
    van Oers, Lauran
    Leiden University, Netherlands.
    Guinée, Jeroen B.
    Leiden University, Netherlands.
    Schulze, Rita
    Leiden University, Netherlands.
    Heijungs, Reionout
    TECNALIA Research & Innovation.
    SUstainable management of PRIMary raw materials through a better approach in Life Cycle Sustainability Assessment (SUPRIM)2019Conference paper (Other academic)
    Abstract [en]

    The project focuses on the assessment of the environmental impact of raw materials production and the development of services to better understand sustainability issues in the sector. The main objectives of the project are:

    • Development of a Life Cycle Impact Assessment (LCIA) method to address resource accessibility in sustainability assessment and testing and validatingthe method.

    • Development of Life Cycle Inventory (LCI) datasets through case studies in collaboration with the industrial partners from the mining sector and apply anenvironmental assessment with the aim to better understand the environmental impacts of the production of copper and the sources of these impacts.

    • Bring the service to a broader audience, including the LCIA community, mining companies and their downstream users, policy makers, academia.

    Two case studies have been performed, the Cobre las Cruces mine in Spain, operated by First Quantum Minerals Ltd, as well as the Aitik mining operation innorthern Sweden, operated by Boliden Mineral AB.

  • Jonsson, Julia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Förslag på riktvärden för sulfathalter i ytvatten2019Independent thesis Basic level (university diploma), 80 credits / 120 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete kommer att vara den avslutande delen i mina studier inom samhällsbyggnads-programmet vid Luleå tekniska universitet. Under min verksamhetsförlagda utbildning, på WSP Sverige AB har jag fått arbeta i uppdrag där kunskaper om vattenkemi och biologi har behövts. Syftet med examenarbetet är att undersöka möjliga förslag på riktvärden för sulfathalter i ytvatten. Examensarbetet tog sin början med att formulera frågeställningar att forma arbetet kring. Utifrån frågeställningarna har jag sedan börjat undersöka vilka länder som har riktvärden för sulfathalter implementerat i miljölagstiftningen. Valet var självklart, att hitta ett land med liknande klimat som norra Sverige för att riktvärdena skulle vara relevanta och trovärdiga. Valet blev att undersöka riktvärden i Kanada. Under examensarbetets gång har jag fått lära mig mycket. Till exempel att kunna läsa och ta till mig information om toxikologiska undersökningar och förstå dess relevans. Detta har i sin tur lett till att jag lärt mig nya begrepp som används inom området miljö och vatten. Jag har även fått en inblick över hur komplext och stort arbetet området miljö och vatten är och fått en bra grund att stå på inför kommande utmaningar i mitt framtida yrkesliv.

  • Marklund, Arvid
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Johansson, Adrian
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Redesigning the production system at the crossmember painting line2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis was performed in collaboration with Scania Ferruform in Luleå, with the purpose to create an efficient, rational and safe workplace at the unloading station of the crossmember painting line. The mission from Ferruform was to investigate and analyse flaws, risk, and bottlenecks with regards to flows, ergonomics and material handling. The project aimed to create a vision that could guide present and future development, followed by an implementation strategy consisting of concrete measures of both layout and organisational character. The vision is:

    “Create a work situation that is rooted in Scania's production system and characterized by efficiency, rationality and safe working conditions, where committed individuals can be challenged and developed”

     

    The research questions that has guided the project are:

    1. What problem is the basis for the ergonomic situation at the crossmember painting?
    2. How can an efficient and rational workplace be created at crossmember painting?
    3. What does Ferruform need to do to create a safe and sustainable work environment at the crossmember painting?

     

    The first step was to map the current state and identify problems with regards to process and organisation. This was done by using participative observation, interviews, user participation, overview analysis and Scania’s intranet. Apart from previous studies, the main problems that the mapping identified was consequences of frequent downtimes, shifts being isolated and having unique work methods, unsafe work environment, and finally that tools and aids for reducing harmful lifts are not used.  These problems and their consequences were analysed with regards to the current research in work science, behavioural science, and by using methods such as Fault tree analysis and proximity chart.

    One of the most important conclusions was that downtime, apart from compromised production volumes, affected the work situation negatively. Operators compensate for downtime by working faster and unsafe to reach the weekly production goals. Additionally, a middle manager role has disappeared in favour of meeting the production goals. This has severe consequences on the organisation of work and among others, ergonomics. The proximity chart showed that placement of functions in the production system is not based on logic, resulting in safety issues, intersecting flows and inefficient handling of materials.

    To counter the identified problems, three different layouts were developed and evaluated using the specification of requirements. The concept with highest score was further developed and detail designed. It is called “Wing” and separates humans and forklifts, has a centralized material buffer and redundancy for downtime. The concept allows for safer work environment, and efficient flows. The required changes are arranged in three steps, each with increasing capacity. The final concept together with the implementation plan, which present recommendations on how the final concept could gradually be implemented and what organisational changes that are needed, shows that productivity and rationality can coexist with a good work environment, where both humans and the production system can flourish.

  • Mulenshi, Jane
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Khavari, Pourya
    Rosenkranz, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Characterization and feasible physical separation methods for Yxsjöberg historical tungsten ore tailings2019Conference paper (Other academic)
    Abstract [en]

    Relatively high minerals and metals content characterize historical tailings due to less efficient extraction methods and/or relatively low metal prices at the time. Repositories of such tailings pose environmental risks but could also become metals and minerals resources. An example of such tailings is the Yxsjöberg historical tungsten ore tailings in the Smaltjärnen tailings repository in Sweden.   

    The Smaltjärnen tailings repository was sampled by collecting drill core samples from different locations. The collected drill core samples were characterized physically (colour, texture, moisture content and particle size distribution) and chemically (elemental composition and distribution, and mineralogical composition). Feasible physical separation methods (magnetic and gravity separation) were pre-selected based on the tailings characteristics and the knowledge of processes from which the Yxsjöberg historical tailings were produced.

    In this paper, results from three drill cores each representing a different location on the tailings repository are presented. The tailings mass distribution was high in the coarser particle size fractions of +300 µm and +149 µm.  Tungsten (W) and Copper (Cu) were the metals of interest with one location having higher concentrations than the other two at 0.20 %WO3 and 0.14 %Cu. Sulphur (S) was recovered in the magnetic fractions of the LIMS and HIMS. Using the Knelson concentrator, W recovery was enhanced. These results are fundamental in the development of methods for separation of minerals and extraction of metals of interest from the historical tailings in order to leave behind an inert and environmentally safe residue.

  • Teng, Penghua
    et al.
    Resources, Energy & Infrastructure, Royal Institute of Technology, 10044 Stockholm, Sweden.
    Yang, James
    Concrete Structures, Royal Institute of Technology, 10044 Stockholm, Sweden, jamesya@kth.se. Vattenfall AB, R&D Hydraulic Laboratory, 81426 Älvkarleby, Sweden..
    Xie, Qiancheng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Improving Energy Dissipation of a Spillway with Structural Modifications2019Conference paper (Refereed)
  • Bilal, Ahmed
    et al.
    College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China.
    Xie, Qiancheng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    The Numerical Study of Open Channel Junctions with Extreme Confluence Angles for Surface Flow without Wall Roughness2019Conference paper (Refereed)
  • Xie, Qiancheng
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Joshi, Ishwar
    Hydro Lab, 21093 Lalitpur, Nepal.
    Yang, James
    Concrete Structures, Royal Institute of Technology, 10044 Stockholm, Sweden.Vattenfall AB, R&D Hydraulic Laboratory, 81426 Älvkarleby, Sweden..
    River-Bed Down-Cutting Equilibrium of a Reach on Yangtze River2019Conference paper (Refereed)
  • Jangholm Melin, Lucas
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Pedersen, Adam
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Likabehandlingens samspel med miljökrav och korruption i offentlig upphandling2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Den offentliga upphandlingen i Sverige är ett omfattande område både juridiskt och ekonomiskt. Lagen är tänkt att vara ett precist redskap för att skapa klara riktlinjer för både den upphandlande myndigheten och för de anbudsläggande leverantörerna. Bristande kunskap och erfarenhet på området leder dock till att domstolar tvingas avgöra fall där lagen har misstolkats eller dess regler inskränkts. Implementering av ett flertal EU-direktiv på området har resulterat i dagens Lag (2016:1145) om offentlig upphandling. Syftet med lagen är att skapa en effektiv konkurrens på marknaden för omsättning av varor och tjänster inom den offentliga sektorn. Det är en bitvis komplex lagstiftning med ett flertal grundläggande principer som ska respekteras och följas. På senare år har vikten av miljöhänsyn i samband med (offentlig) upphandling fått ökad betydelse. Det leder till att både social- och miljöaspekter har fått betydelse för processen. Upphandlare har ett större utrymme att använda dessa aspekter som utvärderingskriterier. Det har medfört ytterligare problem med lagens tolkning. Miljökrav kan försvåra möjligheten för leverantörer att kunna ses som likvärdiga i förhållande till lokala leverantörer som kan ha lättare att uppfylla ett sådant miljökrav. En möjlig konsekvens av de ökade kraven på miljöhänsyn är att andra principer, t.ex. principen om likabehandling, inskränks. Principens stora betydelse för rättvisa i upphandlingsprocessen har emellertid fastslagits i praxis såväl i Sverige som i andra EU-länder. Ett annat problem på området är att det kantats av korruption och maktmissbruk. Risken för maktmissbruk och korruption är som störst i direktupphandling, där man kan välja sin leverantör direkt utan att göra en konkurrensutsättning. Risken för korruption är också större på mindre orter där vänskapsrelationer ofta har en större betydelse. Principen om likabehandling är central inom offentlig upphandling och ses som oklar, eftersom den inte står uttryckligen i lagen. Däremot har domstolar, både i Sverige och i övriga EU-länder, genom praxis klargjort principens mycket stora betydelse för rättvisa i upphandlingsprocessen.

  • Granberg, Linus
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    The role of instagram in choosing a travel destination2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this research has been to explore and further describe the use of Instagram for destination marketing. The purpose of this study was to better understand how marketing objectives can be achieved using Instagram. Based on the research question a literature review was formed. Methodologically a quantitative approach was used. The data was collected from the Instagram account of Swedish Lapland. The finding indicates that Instagram is a place where people find new travel destinations, the app is one of the primary sources of this information and some people buy trips with the information they find on the app.        

  • Ylmefors, Andreas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Deformationsmätningar av förstärkningsbågar i biotitområden i LKAB:s gruva i Malmberget2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I takt med att gruvbrytningen går djupare förändras förutsättningarna för malmbrytning. Med djupet ökar de vertikala bergspänningarna och beroende på brytningsmetod kan även de horisontella bergspänningarna öka. Geologin förändras också genom att vissa bergarter och mineral kan bli ovanligare på djupare nivåer och andra kan bli vanligare. Flera andra omständigheter kan förändras i takt med att mer bergmaterial tas ut. Dessa faktorer ställer höga krav på en fungerande bergförstärkning för att säkerställa personalens säkerhet och för att göra det möjligt att uppnå den planerade produktionskapaciteten. Kunskap om bergförstärkningens egenskaper är därför mycket viktig. Dess styrkor och svagheter måste kännas till. Detsamma gäller bergförstärkningens livslängd. I LKAB:s underjordsgruva i Malmberget har vissa malmkroppar länge haft problem med förekomst av biotitskiffer i malmkontakten. Biotit är ett anisotropt mineral som har mycket dålig hållfasthet. Det orsakar problem för ortstabiliteten, speciellt i området Alliansen – Hoppet – Prinzsköld där vissa ortar har blivit kraftigt deformerade, eller till och med rasat ihop. För att hantera stabilitetsproblemen i området testas en ny variant av bergförstärkning. Förstärkningsbågar bestående av nätkorgar av stål täcks med fiberarmerad sprutbetong och minst 7 meter långa wirebultar installeras genom dessa. Eftersom det är en ny bergförstärkningsmetod är inte dess hållbarhet och deformationsbeständighet dokumenterad. I detta arbete mäts deformationerna i några utvalda förstärkningsbågar i syfte att undersöka hur deformationerna utbildas och vilka samband de har med sprängningar, geologi, seismisk aktivitet och den omgivande bergmassans deformationer. Resultatet av arbetet visar att det är en mycket komplex situation med många variabler som troligen samverkar för att orsaka deformationerna. För att övervaka den nya förstärkningen rekommendera

  • van Eldert, Jeroen
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Johansson, Daniel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Saiang, David
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Application of Measurement While Drilling Technology to Predict Rock Mass Quality and Rock Support for Tunnelling2019In: Rock Mechanics and Rock Engineering, ISSN 0723-2632, E-ISSN 1434-453XArticle in journal (Refereed)
    Abstract [en]

    A tunnelling project is normally initiated with a site investigation to determine the in situ rock mass conditions and to generate the basis for the tunnel design and rock support. However, since site investigations often are based on limited information (surface mapping, geophysical profiles, few bore holes, etc.), the estimation of the rock mass conditions may contain inaccuracies, resulting in underestimating the required rock support. The study hypothesised that these inaccuracies could be reduced using Measurement While Drilling (MWD) technology to assist in the decision-making process. A case study of two tunnels in the Stockholm bypass found the rock mass quality was severely overestimated by the site investigation; more than 45% of the investigated sections had a lower rock mass quality than expected. MWD data were recorded in 25 m grout holes and 6 m blast holes. The MWD data were normalised so that the long grout holes with larger hole diameters and the shorter blast holes with smaller hole diameters gave similar results. With normalised MWD data, it was possible to mimic the tunnel contour mapping; results showed good correlation with mapped Q-value and installed rock support. MWD technology can improve the accuracy of forecasting the rock mass ahead of the face. It can bridge the information gap between the early, somewhat uncertain geotechnical site investigation and the geological mapping done after excavation to optimise rock support.

  • Gabrielsson, Sebastian
    et al.
    Luleå University of Technology, Department of Health Sciences, Nursing Care.
    Ejneborn-Looi, Git-Marie
    Luleå University of Technology, Department of Health Sciences, Nursing Care.
    Recovery-Oriented Reflective Practice Groups: Conceptual Framework and Group Structure2019In: Issues in Mental Health Nursing, ISSN 0161-2840, E-ISSN 1096-4673Article in journal (Refereed)
    Abstract [en]

    The recovery-oriented reflective practice group (RORPG) is a staff-directed intervention aimed at achieving the recovery-focused transformation of mental health settings. This discussion paper aims to outline and reflect on the conceptual framework and group structure of recovery-oriented reflective practice groups. RORPGs build on conceptualizations of reflective practice, personal recovery, mental health nursing as a relational and reflective practice, and abductive reasoning. Dewey’s phases of reflection, together with an understanding of nursing practice as a dynamic process of care, provide a structure for group sessions in which abductive reasoning can be considered a core activity. This paper outlines a sound theoretical foundation and suggests that RORPGs might prove useful for providing a space for learning in practice, informed by both theoretical and practical knowledge.

  • Friis-Jespersen, Isak
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Okembia - Jonsson, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Utveckling av e-läromedel för test-baserat lärande2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There is a increasing number of enrolled students in higher education, which leads toless personal time with the teachers, and therefore supplementary technologies needs to takeplace. This paper investigate how Testbased learning with feedback affects the learningoutcomes in a group of students, by measuring their perceived value. The research also investigateswhat design principles to follow, when working with E-learning and Testbasedlearning with feedback. For this this research an IT-artefact will be created which the studentwill be able to use as a practice tool. With the IT-artefact they will be able to answera number of question, in a subject, and get personalized feedback depending on their score.The quantitative research will then evaluate whether the students perceived thoughts aboutthe IT-artifact and the learning method itself. The result shows eight design principles onhow to design an E-learning tool where student should learn through Test based learningwith feedback. The result also indicates that the perceived feeling of learning is good eventhough a big number of respondents never participated in the survey.

  • Kampmann, Tobias Christoph
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Proceedings of the Visual3D conference 2019, 1–2 October 2019, Uppsala, Sweden: Visualization of 3D/4D models in geosciences, exploration and mining2019Conference proceedings (editor) (Refereed)
    Abstract [en]

    Dear colleagues,

    On behalf of the organizing committee of the Visual3D conference 2019, with the theme “Visualization of 3D/4D models in geosciences, exploration and mining”, I would like to present this proceedings document, containing all abstract contributions for which publication permission has been granted by the authors.

    EIT Raw Materials is especially acknowledged as the main sponsor of this event through the Visual3D network of infrastructure.

    We wish to thank all the contributors who through their efforts made this conference possible, and hope to see you all at a similar event in the near future.

    Yours sincerely,

    Tobias C. Kampmann, PhDConference coordinator, Visual3D conference 2019

  • Shastri, Bhardwaj
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Design and analysis of mission and system requirements for 'NetSat' mission with respect to structural and thermal limitations2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the scope of this master thesis work, the proposed design for NetSat was analyzed for mission and system requirements with respect to structural and thermal limitations. Different load case scenarios for structural and thermal analysis were considered during the process which have been discussed. Based on results, the design is qualified and expected to satisfy all mission and system requirements with regards to structural and thermal limitations.

  • Simon, Hellgren
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Secondary Steel Metallurgy Slag Design and MgO-C Refractory Implications: Theoretical and Practical Considerations2019Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [en]

    MgO-C based refractory materials, often used in secondary steel making, are exposed to variouswear mechanisms in its application. The wear could be divided into oxidative, chemical andabrasive categories, all behaving differently and all being influenced by different factors. Dueto the importance of minimizing material loss and to the environmental challenges to run asustainable industry, it is of interest to gain more knowledge of the behavior of the refractorymaterial in use. The present thesis work specifically investigated slag designed of the CaOSiO2-Al2O3-MgO (CSAM) system as well as the chemical and oxidative wear mechanisms ofthree different MgO-C based refractory materials from Höganäs AB, Halmstadverken, whichcontained 5, 10 and 12 wt% carbon (labeled T05, T10 and T12). Different CSAM slags weredesigned to meet certain process criteria such as MgO and CaO saturations and wereinvestigated through thermodynamic calculations using the FactSage software and throughlaboratory scaled slag smelting experiments. The oxidation effect on the refractory material wasalso studied through pre-heating simulations in chamber furnaces, similar to the pre-heating ofa re-built ladle furnace.The thermodynamic calculations made in FactSage 7.0, using the FactPS and FToxid databases, resulted in a few different slag designs with different properties. A few different slagsfulfilled the CaO and MgO saturation limits proposed by Höganäs AB and could be consideredto test experimentally for further evaluation. The simulations also showed trends on how theliquid viscosity behaved with different slag compositions and how the solids content changedwith temperature.The oxidation experiments were performed on the different MgO-C refractory types, where thebricks with 10% carbon also contained Al2O3 antioxidants. The experiments showed that themass loss during the pre-heating is greater for refractory with higher carbon content, withexception to T10, where the mass losses were measured to 3.76 – 4.01%, 1.06 – 1.28% and6.28 – 6.33% for T05, T10 and T12 respectively. Further, the oxidation depth of each materialwas measured to 9-10 mm, 2-3 mm and 2-5 mm for the T05, T10 and T12. The experimentsalso showed that T12 refractory in particular was very susceptible to abrasive wear after beingoxidized.The slag smelting experiments were carried out through two different methods, by melting slagin MgO-C crucibles and by melting pressed slag briquettes on top of refractory bricks. Theformer tests mainly showed that the methodology was not suitable for this type of refractorymaterial due to the crucibles cracking during the experiments. The latter experiments showedsome general behaviour of the different components in the slag, where Ca, Al and Fe stayednear the surface, and Si and Mg penetrated deeper. The spinel formation at the refractory surfacewas then concluded to be the reason for Al not penetrating deeper. Further it was concludedthat no significant difference in refractory dissolution was seen between slags with- and withoutMgO, other than possibly a small increase in refractory dissolution for the latter.

  • Zankov, Ivan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Optimization of Cubesat-Compatible Plasma Ion Analyzer for Asteroid Composition Analysis2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Many space probes have conducted in situ explorations of asteroids, in recent decades, intent on identifying evidence of the solar system's earliest processes of formation within the asteroids' interiors. Several future asteroid missions are planned, among which include ESA's Hera mission to explore the Didymos binary asteroid pair. An ion mass analyzer is currently being designed at the Swedish Institute of Space Physics for use as part of the Hera mission.

    This thesis aims to optimize the instrument such that each of its parameters meets the requirement for performance. A computer simulation is used to calculate the trajectories of low-energy ions inside the instrument, where the electrostatic potential are imposed by grids and electrodes embedded inside the instrument. From the data analysis of the simulation results, the performance for each parameter can be derived. By changing the settings of the grids and electrodes (e.g., positions and voltages), the instrument parameters are to be optimized. Two tasks are set up in this project--- the first task is to optimize the focusing system of the incoming ions at the instrument's entrance, and the second task is to investigate the reflectron system so that the mass resolution of the instrument can be optimized via reducing the spread of the ions' time of flight spectra.

    The focusing system is found to already be optimized, but instead, a relation between its position of the grid at the instrument's entrance and the instrument's performance is derived. The method of and parameters for optimization within the reflectron are extensively tested individually during this project. Although several performances in each trial from the reflectron analysis cannot meet at least one of the requirements, enough scenarios are examined such that every parameter tested ends with a value suitable to be applied individually to optimize the ion mass analyzer. The findings from the individual tests done in this project can be applied to further optimization, particularly to optimize multiple parameters simultaneously in the near future.

  • Mosquera Alonso, Andrea
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    State- and Parameter Estimation for Spacecraft with Flexible Appendages using Unscented Kalman Filters2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The problem of system identification for dynamic effects on spacecraft has become increasingly relevant with the surge of agile spacecraft, which must perform large amplitude maneuvers at high rates. Precise knowledge of the state of the spacecraft, as well as of the parameters characterizing its motion, is vital for the design of control algorithms enabling stabilization and pointing accuracy. Traditional rigid body models and estimation methods are no longer sufficient to provide this knowledge. This thesis focuses on estimation of flexibility effects and spacecraft parameters through methods based on the unscented Kalman filter, an estimator for nonlinear dynamic systems. A spacecraft model consisting of a rigid central body and a flexible appendage described as an Euler-Bernoulli beam in pure bending is built, and equations for its translational and rotational motion, as well as the deflection of the beam, are derived in the Newton-Euler framework considering the first bending mode of the flexible deformation. Observability tests are successfully conducted to ensure that estimation of the relevant states and parameters can be performed exclusively from linear and angular velocity measurements.

    A total of eight filters, estimating the spacecraft’s state along with different combinations of parameters, are developed, implemented, and tested on simulated data. Grouped under the common denomination “UFFE” (Unscented Filter for Flexibility Effects), they are made available as Simulink library blocks. State estimation is performed for the linear and angular velocities of the spacecraft and the modal coordinate and velocity of the appendage, with estimates following closely the truth model of the state variables and estimation errors at least an order of magnitude lower than true state values. Simultaneous state and parameter estimation is implemented from two approaches, joint estimation and dual estimation, whose performance and applications are compared. Estimated parameters include the moments of inertia of the system and natural frequency, damping ratio, and modal participation factors of the flexible appendage. Convergence to true parameter values is reached in the first 100s of the estimation for inertia terms and natural frequency, while the estimation for modal participation factors is conditioned to precise tuning of the filter. Estimates of the damping ratio are biased, most likely due to the control input not being optimal for observation of this parameter. The dual approach to parameter estimation is found to be advantageous when proper filter tuning is possible, as it enables the continuous operation of a state filter combined with short runs of the parameter filter activated at will; this configuration could be employed to track the variation of spacecraft parameters along space missions.

     The causes of estimation error are identified and methods for automatic tuning of the process noise and process noise covariance are researched. Five such tuning techniques are implemented and tested, with promising results found for online sampling of the process noise covariance through Monte Carlo methods. A discussion on the limitations of the chosen dynamic model and estimator, along with recommendations for extensions and future applications, concludes this work. 

  • Schweitzer, Nike
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Ohlsson, Sanna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Förstudie om ny standard för släcksystem i tunga gruvfordon: en analys av aktuell situation och framtida behov2019Independent thesis Basic level (professional degree), 210 HE creditsStudent thesis
    Abstract [sv]

    En brand i en gruva skiljer sig åt jämfört med en brand i en byggnad. Vid brand i en undermarksanläggning uppstår ett omedelbart hot mot de människor som vistas där. Vid en gruvbrand påverkar faktorer såsom sikt, obefintligt dagsljusinsläpp och begränsade utrymningsmöjligheter. Händelserna vid en brand kan också orsaka kostsamma driftstopp i gruvproduktionen. Det finns även en tydlig skillnad i problematik vid räddningsinsatser. Vid en gruvbrand måste räddningstjänsten exempelvis beakta långa inträngningsvägar, begränsade ventilationsmöjligheter, risken för ras och osäker brandvattenförsörjning. Under de senaste tio åren har det inträffat i snitt 70 bränder per år i svenska gruvor, varav cirka hälften varit fordonsrelaterade. Idag installeras därför släcksystem i gruvfordon i syfte att försöka minimera den typen av bränder.

     

    För att kartlägga användandet och erfarenheterna av fordonssläcksystem samt undersöka vilka framtida behov som finns gällande gruvfordons släcksystem och regelverken inom ämnesområdet genomfördes denna förstudie i samråd med RISE.

     

    Förstudien baseras på semi-strukturerade intervjuer med respondenter som valts ut utifrån deras kunskap inom bränder i underjordsgruvor och släcksystem. Även statistik från Gruvindustrins arbetsmiljökommitté gällande bränder i gruvfordon sammanställdes och studerades.

     

    I intervjustudien framgår det att effektiviteten på dagens släcksystem är montörsberoende och att det finns anledning till att konkretisera regelverken och specificera hur släcksystemen bör optimeras. Studien pekar på att effektiviteten hos släcksystem bland annat påverkas av luftflöden, mekanisk påverkan och bristfällig skötsel av systemen. Flera respondenter poängterar även att mängden släckmedelsvätska som används i dagens system måste verifieras gentemot respektive gruvfordons riskprofil. Det finns också en tydlig problematik i verkställandet och noggrannheten av kontroll och underhåll av släcksystemen och respondenterna är eniga om att en förbättring är nödvändig.

     

    Studien visar att ett av de regelverk som tillämpas för släcksystem på fordon i gruvor i Sverige, SBF 127:16, inte beaktar problematiken med bränder i undermarksanläggningar. Det framgår även att de provningarna som genomförs på släcksystem delvis är baserade på information ifrån tidigt 90-tal. Vid verkställande av framtida regelverk bör större hänsyn tas till gruvindustrins specifika behov. År 2018 finns det även en osäkerhet kring fordonssläcksystemens prestanda. Gruvindustrin önskar släcksystem med tillhörande regelverk som är optimerade efter deras behov gällande fordon och miljö.

  • Hessinger, Felix
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Automation of Operation and Testing for European Space Agency's OPS-SAT Mission2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis presents a solution for mission operation automation in European Space Agency’s (ESA) OPS-SAT mission. To achieve this, the ESA internal mission automation system (MATIS) in combination with the mission control software (SCOS) are used. They control the satellite and all ground peripherals and programmes to enable fully automated and unsupervised satellite passes. The goal of this work is the transition from the existing manual operation, with a human operator watching over and controlling all systems, to an automated system. This system supports the operation engineer and replaces the operator himself. A large section of this thesis consists of the setup, configuration, integration of all programmes and virtual machines and testing of the MATIS software, as well as the Service Management Framework (SMF) which connects MATIS to non-MATIS applications like SCOS. During testing, many problems could be identified, not only OPS-SAT specific ones, but also general problems applying to all missions that consider using MATIS for future operation automation. These findings and bugs discovered during testing are reported to the responsible authorities and presented in this work. Further features of this thesis are the elaborations of the mission operation automation concept and the satellite pass concept, providing an in-depth view of the automation and passes of OPS-SAT as well as the general concepts and thoughts, which can be used by other missions to accelerate integration. An additional key feature of this thesis is the newly developed standard for operation notation in Excel, which has been achieved in close cooperation with the operation engineer. Furthermore, to accelerate the process of switching from manual to automated procedures, several converters have been developed iteratively with the new standard. These converters allow fast transformation from Excel to the procedure programming language called PLUTO used by MATIS. Not only do the results and converters of this work accelerate the procedure integration by 80%, they also deliver a more stable mission automation system that can be used by other missions as well. Operation automation reduces the operational costs for satellites and space missions significantly, as well as reducing the human error to a minimum. Therefore, this thesis is the first step towards a future with complete automation in the area of satellite operations. Without this automation, future satellite cluster configurations, like Starlink from SpaceX, will not be possible to put into practice, due to their high complexity, exceeding the comprehensibility and reaction time of humans.

  • Persson, Simon
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Konstruktion för demonteringslösning av formahus2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • Nilsson Harnert, Henrik
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Metadata Validation Using a Convolutional Neural Network: Detection and Prediction of Fashion Products2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the e-commerce industry, importing data from third party clothing brands require validation of this data. If the validation step of this data is done manually, it is a tedious and time-consuming task. Part of this task can be replaced or assisted by using computer vision to automatically find clothing types, such as T-shirts and pants, within imported images. After a detection of clothing type is computed, it is possible to recommend the likelihood of clothing products correlating to data imported with a certain accuracy. This was done alongside a prototype interface that can be used to start training, finding clothing types in an image and to mask annotations of products. Annotations are areas describing different clothing types and are used to train an object detector model.

    A model for finding clothing types is trained on Mask R-CNN object detector and achieves 0.49 mAP accuracy. A detection take just above one second on an Nvidia GTX 1070 8 GB graphics card.

    Recommending one or several products based on a detection take 0.5 seconds and the algorithm used is k-nearest neighbors. If prediction is done on products of which is used to build the model of the prediction algorithm almost perfect accuracy is achieved while products in images for another products does not achieve nearly as good results.

  • Palm, Jonathan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Optimization of 5G New Radio for Fixed Wireless Access2019Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [en]

    With the advent of new 5G networks, the interest in connecting house-hold to the Internet via mobile networks has increased. One such way toconnect users is using completely stationary antennas. This use-case iscalled Fixed Wireless Access (FWA) and is seen as promising, cost-efficient means of expanding internet connectivity. Stationary users connected at high frequencies, such as 28 GHz, leads to a special use-case and environment for 5G New Radio (NR). This thesis investigates the characteristics of these FWA deployments and the control signaling on the physical layer of NR. The overhead and feasibility of eachsignal is considered. A FWA deployment in the 28 GHz band with 64 users is simulated with different line-of-sight settings and receiver placements. It is concluded that direct line-of-sight to the base station is vital for high user and cell throughput and that there are significant drawbacks of placing the receiver indoors. New algorithms for Channel State Information Reference Signal (CSI-RS) transmission for both beam management and link adaptation are proposed and evaluated. The beam management algorithms do not displayany significant performance gains over the default sweeping algorithm. Closer investigation of simulation results shows that several beams can have almost equal signal strength with the chosen antenna set up, minimizing potential gains of quickly adapting to environmental changes. Results show there are clear benefits of using an aperiodic and adaptive transmission scheme for CSI-RS transmissions over a fixed-rate transmission scheme, yielding a 7% increase in user goodput at similar levels of overhead.

  • Herrmann, Inga
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Larsson, Charlotta
    Wilen, Britt-
    Slambildning och mikrobiell sammansättning av biofilm i infiltrationsanläggningar2019Report (Other academic)
  • Bhagat, Suraj Kumar
    et al.
    Faculty of Civil Engineering, Ton Duc Thang University, Ho Chi Minh City, Vietnam. Department of Civil Engineering, Institute of Technology, Ambo University, Ambo, Ethiopia.
    Tiyasha, Tiyasha
    Faculty of Civil Engineering, Ton Duc Thang University, Ho Chi Minh City, Vietnam. Department of Civil Engineering, Institute of Technology, Ambo University, Ambo, Ethiopia.
    Welde, Wakjira
    Department of Civil Engineering, Institute of Technology, Ambo University, Ambo, Ethiopia.
    Tesfaye, Olana
    Department of Civil Engineering, Institute of Technology, Ambo University, Ambo, Ethiopia.
    Tung, Tran Minh
    Faculty of Civil Engineering, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Salih, Sinan Q.
    Institute of Research and Development, Duy Tan University, Da Nang, Vietnam.
    Yaseen, Zaher Mundher
    Sustainable Developments in Civil Engineering Research Group, Faculty of Civil Engineering, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
    Evaluating Physical and Fiscal Water Leakage in Water Distribution System2019In: Water, ISSN 2073-4441, E-ISSN 2073-4441, Vol. 11, no 10, article id 2091Article in journal (Refereed)
    Abstract [en]

    With increasing population, the need for research ideas on the field of reducing wastage of water can save a big amount of water, money, time, and energy. Water leakage (WL) is an essential problem in the field of water supply field. This research is focused on real water loss in the water distribution system located in Ethiopia. Top-down and bursts and background estimates (BABE) methodology is performed to assess the data and the calibration process of the WL variables. The top-down method assists to quantify the water loss by the record and observation throughout the distribution network. In addition, the BABE approach gives a specific water leakage and burst information. The geometrical mean method is used to forecast the population up to 2023 along with their fiscal value by the uniform tariff method. With respect to the revenue lost, 42575 Br and 42664 Br or in 1562$ and 1566$ were lost in 2017 and 2018, respectively. The next five-year population was forecasted to estimate the possible amount of water to be saved, which was about 549,627 m3 and revenue 65,111$ to make the system more efficient. The results suggested that the majority of losses were due to several components of the distribution system including pipe-joint failure, relatively older age pipes, poor repairing and maintenance of water taps, pipe joints and shower taps, negligence of the consumer and unreliable water supply. As per the research findings, recommendations were proposed on minimizing water leakage.

  • Jägare, Veronica
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Juntti, Ulla
    Omicold AB.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Governance of digital data sharing in a cross-organisational railway maintenance context2019In: Proceedings of the 5th International Workshop and Congress on eMaintenance: eMaintenance: Trends in Technologies & methodologies, challenges, possibilites and applications / [ed] Arranz, Miguel Castano, 2019Conference paper (Refereed)
    Abstract [en]

    The purpose of this paper is to study and explore the essential aspects of data governance in eMaintenance that need to be considered such as data sharing and data ownership in a cross-organisational railway maintenance context. Furthermore, the paper develops and provides an approach to strategies and guidelines, which can be used to govern digital data sharing.

    To fulfil this purpose, case studies of several projects where sharing of data between stakeholders in order to develop maintenance decision support, was selected as a research strategy and supported by a literature study. Empirical data were collected through interviews, workshops, document studies, and observations. An approach was developed and validated using a case study.

    The proposed approach supports the understanding and establishing strategies and guidelines for data governance in a cross-organisational railway context. This can be considered as one of the enablers for information logistics for maintenance purposes where the approach can be used as a support tool in order to facilitate the development of maintenance decision support within the railway industry.

  • Wernicke, Brian
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction.
    Lidelöw, Helena
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction. Lindbäcks bygg.
    Simu, Kajsa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction.
    Flow Dimensions at Swedish Construction Contractors2019In: Lean Construction Journal, ISSN 1555-1369, E-ISSN 1555-1369, Vol. 2019, p. 24-46Article in journal (Refereed)
    Abstract [en]

    Research Question: How do different flow dimensions and their interrelations appear in Swedish construction settings?

    Purpose: To contribute to the ongoing discussion on flow in construction by providing empirical data to a proposed flow model and widening the current understanding within Lean Construction with theory from industrialized construction and operations management.

    Research Design: Transcriptions of nine in-depth interviews with managers at different Swedish contractors were utilized to identify different flow dimensions.

    Findings: Results show different patterns which describe contractors’ focus on different flow dimensions.

    Limitations: The study is performed in Swedish construction companies with limited generalizability to construction in general. Data collection based on interviews might struggle with objectivity and multi-case studies do not coincide with in-depth research in each single case.

    Implications: Different flow dimensions are relevant within construction contractors and should be addressed by either management activities or an operations strategy.

    Value for practitioners: Increased understanding of flow in construction based on empirical data enables management of different flow dimensions to evolve contractors’ operations strategies towards Lean Construction or industrialized construction.

  • Strandberg, Carola
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Styvén, Maria
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    What’s love got to do with it?: Place brand love and viral videos2019In: Internet Research, ISSN 1066-2243Article in journal (Refereed)
    Abstract [en]

    Purpose

    The purpose of this paper is to explore the role of brand love in place brand communication by incorporating potential antecedents and behavioral outcomes of place brand love in a social media setting.

    Design/methodology/approach

    Data were gathered from 281 residents and visitors of a place through an online survey focusing on a place brand video. Structural equation modeling was employed to examine the research model.

    Findings

    Results show that place brand love has a strong direct relationship with positive word of mouth (WOM), and an indirect effect on intention to share the place brand message. Self-expressiveness of the place brand message also seems to influence place brand love as well as intention to share the message.

    Research limitations/implications

    The role of self-related concepts and brand love to a place has theoretical implications for research in place branding and electronic word of mouth. The study has limitations to its generalizability in terms of cultural aspects and sample representativeness.

    Practical implications

    Place marketers need to successfully reflect the self-concept of key stakeholders in communication messages in order to increase the probability that recipients will engage in positive WOM and share the message.

    Originality/value

    Research on place brand love is scarce and previous studies have focused solely on brand love in connection to tourists. The main contribution of the current study is the exploration of the role of brand love in connection to residents, who are vital co-creators of the place brand.

  • Kadhim, Ali
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Birk, Wolfgang
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Arranz, Miguel Castano
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Dynamic Relative Gain Array Estimation using Local Polynomial Approximation Approach2016In: Model, Identificationand Control, ISSN 1890-1328, Vol. 37, no 4, p. 247-259Article in journal (Refereed)
    Abstract [en]

    This article presents a procedure that utilizes the local polynomial approximation approach in the estimation of the Dynamic Relative Gain Array (DRGA) matrix and its uncertainty bounds for weakly nonlinear systems. This procedure offers enhanced frequency resolution and noise reduction when random excitation is used. It also allows separation of nonlinear distortions with shorter measuring time when multisine excitation is imposed. The procedure is illustrated using the well-known quadruple tank process as a case study in simulation and in real life. Besides, a comparison with the pairing results of the static RGA, nonlinear RGA and DRGA based on linearized quadruple tank model for different simulation cases is performed.

  • Merikoski, Jorma K.
    et al.
    University of Tampere, Finland.
    Haukkanen, Pentti
    University of Tampere, Finland.
    Tossavainen, Timo
    Luleå University of Technology, Department of Arts, Communication and Education, Education, Language, and Teaching.
    Arithmetic subderivatives and Leibniz-additive functions2019In: Annales Mathematicae et Informaticae, ISSN 1216-6014Article in journal (Refereed)
    Abstract [en]

    We introduce the arithmetic subderivative of a positive integer with respect to a non-empty set of primes. This notion generalizes the concepts of the arithmetic derivative and arithmetic partial derivative. In order to generalize these notions a step further, we define that an arithmetic function 𝑓 is Leibniz-additive if there is a nonzero-valued and completely multiplicative function ℎ𝑓 satisfying 𝑓(𝑚𝑛) = 𝑓(𝑚)ℎ𝑓 (𝑛) + 𝑓(𝑛)ℎ𝑓 (𝑚) for all positive integers 𝑚 and 𝑛. We study some basic properties of such functions. For example, we present conditions when an arithmetic function is Leibniz-additive and, generalizing the well-known bounds for the arithmetic derivative, we establish bounds for a Leibniz-additive function.

  • Facchetti, Jeremy
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    HAALO: A cloud native hardware accelerator abstraction with low overhead2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With the upcoming 5G deployment and the exponentially increasing data transmitted over cellular networks, off the shelf hardware won't provide enough performance to cope with the data being transferred over cellular networks. To tackle that problem, hardware accelerators will be of great support thanks to their better performances and lower energy consumption. However, hardware accelerators are not a silver bullet as their very nature prevents them to be as flexible as CPUs. Hardware accelerators integration into Kubernetes and Docker, respectively the most used tools for orchestration and containerization, is still not as flexible as it would need. In this thesis, we developed a framework that allows for a more flexible integration of these accelerators into a Kubernetes cluster using Docker containers making use of an abstraction layer instead of the classic virtualization process. Our results compare the performance of an execution with and without the framework that was developed during this thesis. We found that the framework's overhead depends on the size of the data being processed by the accelerator but does not go over a very low percentage of the total execution time. This framework provides an abstraction for hardware accelerators and thus provides an easy way to integrate hardware accelerated applications into a heterogeneous cluster or even across different clusters with different hardware accelerators types. This framework also moves the hardware specific parts of an accelerated program from the containers to the infrastructure and enables a new kind of service, OpenCL as a service.

  • Lauri, Sanna
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Mattson, Hanna
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Ansvar och dilemman vid applikationsutveckling för mobila enheter2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Digitaliseringen av samhället har inneburit stora förändringar för både verksamheter och privatpersoner, såväl möjligheter som utmaningar. Från det att iPhone introducerats har utvecklingen av både smartphones och nya digitala tjänster fått en explosiv tillväxt. I takt med ökningen av dessa nya digitala tjänster och applikationer medför detta både positiva förändringar likväl oavsiktliga konsekvenser. Det finns svårigheter med dessa oavsiktliga konsekvenser vid applikationsutveckling eftersom det är svåra att förutse samt att det är svårt att förutse hur människor kommer agera när de använder den färdiga applikationen. Denna studie syftar till att öka förståelse för vikten av utvecklares ansvar samt utmaningar vid applikationsanvändning, vilket bör uppmärksammas vid applikationsutveckling och nya digitala tjänster.

     

    För att uppnå detta tillämpades designprocessen som har strukturerat studien för att ta fram vårt designförslag som presenteras i form av en prototyp för en parkeringsapplikation samt rekommendationer för utvecklare. Designförslaget och rekommendationerna bygger på den data som har samlats in genom kvalitativa djupintervjuer med utvecklare samt undersökning för hur dagsläget ser ut vad gäller ansvar och dilemman vid utveckling.

     

    Resultatet visar på hur viktigt det är att kravspecifikationer från kunden är väl utförda för att slutprodukten ska uppnå bästa resultat. Däremot finns det inte alltid tillräcklig tydliga riktlinjer att följa inom dessa utvecklingsverksamheter för att fatta beslut. Skulle ett projekt ge upphov till ett dåligt utfall är det upp till den enskilda individen att belysa situationen. En situation där den enskilda individens ansvarsförmåga spelar in. Resultatet av intervjuerna samt rekommendationerna har därmed kunnat generera ett designförslag för hur ansvar kan tillämpas vid applikationsutveckling. Slutsatsen är att vid utveckling bör balans mellan ansvar och användarupplevelse eftersträvas. Utvecklas säkerhetsåtgärder som ska implementeras i en applikation ska de framkalla en positiv attityd och påvisa användare snarare än bestämma över deras interaktion.

  • Lindqvist, Björn
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Combined Control and Path Planning for a Micro Aerial Vehicle based on Non-linear MPC with Parametric Geometric Constraints2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Using robots to navigate through un-mapped environments, specially man-made infrastructures, for the purpose of exploration or inspection is a topic that has gathered a lot of interest in the last years. Micro Aerial Vehicles (MAV's) have the mobility and agility to move quickly and access hard-to-reach areas where ground robots would fail, but using MAV's for that purpose comes with its own set of problems since any collision with the environment results in a crash. The control architecture used in a MAV for such a task needs to perform obstacle avoidance and on-line path-planning in an unknown environment with low computation times as to not lose stability. In this thesis a Non-linear Model Predictive Controller (NMPC) for obstacle avoidance and path-planning on an aerial platform will be established. Included are methods for constraining the available state-space, simulations of various obstacle avoidance scenarios for single and multiple MAVs and experimental validation of the proposed control architecture. The validity of the proposed approach is demonstrated through multiple experimental and simulation results. In these approaches, the positioning information of the obstacles and the MAV are provided by a motion-capture system. The thesis will conclude with the demonstration of an experimental validation of a centralized NMPC for collision avoidance of two MAV's.

  • Mäenpää, Viktor
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    En effektiv produktionskalkyl: Från anbudskalkyl till produktionskalkyl på ett effektivt sätt2019Independent thesis Basic level (university diploma), 80 credits / 120 HE creditsStudent thesis
    Abstract [sv]

    Detta arbete är gjort i utredningssyfte och utredningen är gjord med hjälp av Mäenpää Byggnads Ab. Utredningen tittar närmare på teorin i produktionskalkylen och går igenom hur man skall gå tillväga för att upprätta en produktionskalkyl. Teorin är tagen från litteratur men det har även gjorts intervjuer med Mäenpää byggnads Ab för att se hur de jobbar med ämnet. Utredningen belyser också produktionskalkylens för- och nackdelar. I teorin men även intervjun kan man snabbt se en stor nackdel med produktionskalkylen. Därför tittar utredningen på möjligheter att göra denna produktionskalkyl på ett lite annorlunda sätt än vad teorin säger och på så vis undvika delar av den stora nackdelen. Det blir också tydligt att teorin är mer inriktad mot större företag och större projekt vilket kan göra det svårt för medelstora företag att följa teorin.

  • Nurgazy, Meruyert
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    CAVISAP: Context-Aware Visualization of Air Pollution with IoT Platforms2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Air pollution is a severe issue in many big cities due to population growth and the rapid development of the economy and industry. This leads to the proliferating need to monitor urban air quality to avoid personal exposure and to make savvy decisions on managing the environment. In the last decades, the Internet of Things (IoT) is increasingly being applied to environmental challenges, including air quality monitoring and visualization. In this thesis, we present CAVisAP, a context-aware system for outdoor air pollution visualization with IoT platforms. The system aims to provide context-aware visualization of three air pollutants such as nitrogen dioxide (NO2), ozone (O3) and particulate matter (PM2.5) in Melbourne, Australia and Skellefteå, Sweden. In addition to the primary context as location and time, CAVisAP takes into account users’ pollutant sensitivity levels and colour vision impairments to provide personalized pollution maps and pollution-based route planning. Experiments are conducted to validate the system and results are discussed.

  • Putra, Muhammad Ansyar Rafi
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Trajectory Optimization of Round Trip to Arjuna-type Near-Earth Asteroids from a Lunar Distant Retrograde Orbit Using Lunar Gravity Assist2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Asteroid mining is rapidly becoming a popular topic amongst space community, primarily due to the potential resources that the asteroids can provide for future spacefaring. One of the interesting resources that can be obtained from asteroids is water, which can also be processed into oxygen and fuel. An intriguing concept would be to process fuel from asteroid, and establish a fuel depot in an Earth-centered orbit. This thesis considers a mission concept consisting of travelling to an Arjuna near-Earth asteroid from a lunar distant retrograde orbit as a depot orbit, processing fuel in-situ from the water on the asteroid, and bringing back 100 tons of fuel to the depot orbit.

    In order to minimize fuel consumption for such a trip, the thesis develops an optimization method that can obtain the best trajectory for different phases of the round trip, given certain constraints to ensure the spacecraft successfully reaches the asteroid and comes back to the Earth system.

    The optimization model consists of four steps, i.e., the outbound trip, the first phase of the return trip, the second phase of the return trip, and the optimization for the combined phases of return trip. The outbound trip is the trajectory from the depot orbit to the asteroid. After at least three months of mining, the spacecraft brings back the processed fuel to the vicinity of the Moon. This phase is called the first phase of the return trip. The spacecraft is then captured without an insertion burn to an Earth-centered orbit by a lunar gravity assist maneuver, and travels to the point where the insertion maneuver to the depot orbit begins. This is the second phase of the return trip. The last step of the optimization is the combination of the two phases of return trip, in addition to the final maneuver for entering the lunar distant retrograde orbit.

    The optimization method uses MATLAB fmincon solver, and it was applied to 29 synthetic asteroids. There were 19 converged solutions, but for 10 asteroids the optimizations was not able to converge. The lowest minimum fuel consumption for a trip is 19965.5 kg, and the highest minimum fuel consumption is 61821.4 kg. For the lowest minimum fuel consumption, the duration of the trip is nearly 7 years, and the duration for the highest minimum fuel consumption is about 2.6 years.

  • Svensson, Eskil
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Evaluation of Smart Split-Range Control Strategies for Optimized Turbine and Steam Control in Pulp and Paper Plants2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • Hadi, Sinan Jasim
    et al.
    Department of the Real Estate Development and Management, Ankara University, Ankara, Turkey.
    Abba, S.I.
    Department of Physical Planning Development, Maitama Sule University Kano, Nigeria.
    Sammen, Saad Sh.
    Department of Civil Engineering, College of Engineering, University of Diyala, Diyala Governorate, Iraq.
    Salih, Sinan Q.
    Institute of Research and Development, Duy Tan University, Da Nang, Vietnam.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Yaseen, Zaher Mundher
    Sustainable Developments in Civil Engineering Research Group, Faculty of civil Engineering, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
    Non-linear input variable selection approach integrated with non-tuned data intelligence model for streamflow pattern simulation2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 141533-141548Article in journal (Refereed)
    Abstract [en]

    Streamflow modeling is considered as an essential component for water resources planning and management. There are numerous challenges related to streamflow prediction that are facing water resources engineers. These challenges due to the complex processes associated with several natural variables such as non-stationarity, non-linearity, and randomness. In this study, a new model is proposed to predict long-term streamflow. Several lags that cover several years are abstracted using the potential of Extreme Gradient Boosting (XGB) then after the selected inputs variables are imposed into the predictive model (i.e., Extreme Learning Machine (ELM)). The proposed model is compared with the stand-alone schema in which the optimum lags of the variables are supplied into the XGB and ELM models. Hydrological variables including rainfall, temperature and evapotranspiration are used to build the model and predict the streamflow at Goksu-Himmeti basin in Turkey. The results showed that XGB model performed an excellent result in which can be used for predicting the streamflow pattern. Also, it is clear from the attained results that the accuracy of the streamflow prediction using XGB technique could be improved when the high number of lags was used. However, the implementation of the XGB is tree-based technique in which several issues could be raised such as overfitting problem. The proposed schema XGBELM in which XGB approach is selected the correlated inputs and ranking them according to their importance; then after, the selected inputs are supplied into the ELM model for the prediction process. The XGBELM model outperformed the stand-alone schema of both XGB and ELM models and the high-lagged schema of the XGB. It is important to indicate that the XGBELM model found to improve the prediction ability with minimum variables number.

  • Bäck, Frida
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Influence of bio-coal ash respectively coal structure on coke production and coke quality2019Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [en]

    In recent years, the consequences of global warming have increased the discussion about the climate impact caused by humans and the fossil emissions. Sweden has decided to reduce the negative climate impact with a zero vision for the fossil carbon dioxide emissions in year 2045. In order to achieve this, great efforts and changes are needed both in the inhabitants' way of living but primarily in the base industry. The major cause is the use of fossil coal, which generates fossil carbon dioxide in the steel industry in particular. The fossil coal is added to the blast furnace in the steel process in forms of coke and coal, which reduces the iron and emits heat. The quality of the coke is important as it functions reducing agent, provides a mechanical support to the bed and enables the gas flow up through the blast furnace and enables dissolution of carbon in hot metal. Also, coke supplies energy from exothermic reactions between carbon and carbon dioxide that takes part in the blast furnace and the energy are further used for the heating and melting of the cold iron pellets. Due to these factors, the blast furnace process is dependent on coke for its function, which means that the entire process must be replaced if the steel production should work without fossil coal. However, there are many studies that have been done on how to replace some of the fossil coal with bio-coal, which is produced from biomass. If some of the fossil coal could be replaced by some bio-coal, this would mean that fossil carbon dioxide emissions would decrease and lead to a reduced climate impact. The process would still generate carbon dioxide, but on the other hand, a cycle would be formed because when biomass is grown, carbon dioxide is taken up, e.g. by the trees grown for this purpose. However, bio-coal does not have the same properties as fossil coal, which in turn affects the quality of the coke. Bio-coke is more reactive and more porous than fossil coke. In order to be able to replace fossil coke with bio-coke, it is likely necessary to pre-treat the biocoal before it replaces part of the fossil coal in the coke production. Bio-coal contains ash that acts as an internal catalyst. One theory is that if it is possible to produce a bio-coal with ash-free carbon structure, it can be used in the production of coke without having such a great effect on the coke quality. In this project, the ash's impact on the properties of bio-coal in coke was studied. Previous studies have shown that leaching is an effective method for removing ash from bio-coal. It can be leached in three different ways, either with water, weak acid or acid. However, it has been found that acid leaching has a certain impact on the carbon structure itself. For this reason, two types of bio-coal, torrefied Grot (forest residue) and torrefied sawdust were selected, which were leached both with water but also with weak acid in order to achieve an ash-reduced carbon structure. The acid selected was acetic acid, as it has been tested for similar purposes in previous studies. The leaching efficiency was evaluated by analysing the leachate with ICP-OES after leaching. According to the result, a significant part of the ash had been leached out, but the leaching with weak acid was much more effective than water leaching. To ensure that the carbon structure was not altered, light-optical microscopy was made which showed that the structure was intact. However, it was not possible to determine whether the pore sizes were changed after leaching and it is therefore relevant to investigate this further. Moreover, the leached II bio-coal replaced 5% of the fossil coal in the coal mixture for coke making. In addition to this, coke was also made with only the ash from the two bio-coals to see what effect the ash has on the coke quality. The result that was obtained from the TGA showed that the ash had a low impact on the reactivity of the coke. However, the coal structure of the coke had a great impact on the reactivity behaviour. Keywords: Bio-coke, bio-coal, leaching, ash, coke quality, carbon structures, torrefied sawdust

  • Häggström, Louise
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Attraktiva bytespunkter: Funktionsanalys av stationsmiljöer ur ett användarperspektiv2019Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [en]

    Public transport is an important mode of transportation in today’s society. In Stockholm county large changes are occurring within public transport, because of the population rise that is happening in the county. In many places within the public transport system, a multiple of different types of public transport are meeting. In these places, there has to exist functional station environments.

    This thesis aims to answer the research questions about how the functions accessibility, safety, usability and equality, together with children’s needs, are treated in the planning phase of stations and how these functions in the built environment are fulfilled.

    The theoretical foundation of this thesis includes an extended literature review, where the functions were studied in relation to physical planning and the perception of station and the environments surrounding them. The practical part of this thesis has consisted of making case studies of three stations in Stockholm county, and to research the preconditions of planning that exist in the county.

    The case studies have consisted of document and field studies. The document study was to analyse planning documents for each station. The field studies were made in each station’s real environment. The documents and the physical environments were reviewed with the tool of using representative indicators, that were decided from the results of the literature review. The indicators were used to systematically assess how the functions were experienced in the station environment and how they were described in the documents. Each indicator is defined in relation to how it affects the different functions and needs.

    The thesis work resulted in a larger account for each indicator within the stations in the case studies. This by assessing the planning documents and to state facts about the physical environments of the stations. These results were analysed, where each indicator category had its own segment. The analysis landed in the conclusion that the stations in large parts fulfilled the functions and needs, because the indicators were believed to represent largely positive traits.

  • Tofilovski, Alexander
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences.
    Poppins: The Service and Interaction Design of Babysitting Service2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis is covering a project that focuses on developing both babysitting services and dog walking services and facilitating them through a mobile application. Only the user interface for the service of babysitting was created because the dog walking service was considered to be less of a complex service, and not add to more to the insights in this project. The project was started due to observations that the babysitting service is highly used in America, but it does not operate in a structured fashion. Many parents are new to babysitting which creates uncertainty when ordering and scheduling babysitter. Babysitter, on the other hand, are usually younger and inexperienced.

    The user interface is created with a service design approach. Developing the service though by creating stakeholder maps, customer journeys, and, service blueprints. Creating the user interface with the service blueprint as a reference. By taking this approach business insight where created and the babysitting service could be created as a hollow organization. An organization that combines more than one service to create greater value for the end user.

  • Zwahlen, Carmen
    et al.
    Wogelius, Roy
    University of Manchester.
    Hollis, Cathy
    University of Manchester.
    Holland, Greg
    University of Manchester.
    Reaction path modelling illustrating the fluid history of a natural CO2-H2S reservoir2019In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 109, article id 104391Article in journal (Refereed)
    Abstract [en]

    Despite the increasing interest in geologic co-sequestration of CO2 and H2S, the long-term consequences of the chemical interactions involved in this process remain largely unknown on a reservoir scale. A Mississippian aged CO2-H2S reservoir in LaBarge Field, Wyoming, USA is an ideal study site to investigate mineral and fluid reactions related to gaseous H2S and CO2. We conducted two reaction path models based on mineralogical, fluid, gas, and stable isotope compositional data to discern the role of CO2 influx upon the generation of H2S through thermochemical sulphate reduction (TSR). We discriminate between two models-one in which TSR is triggered by temperature at a given burial depth and one where TSR is triggered by ingress of CO2. The reaction path model based upon burial-controlled TSR and later CO2 influx is consistent with mineralogical observations and stable isotope measurements from drill cores. The models show that CO2 influx leads to calcite precipitation which is only limited by the calcium concentration in the fluid. This modelling approach is useful in constraining the timing of fluid flux in the reservoir and gives further insight into the mineralogical consequences of the gas, water, and rock interactions occurring in the reservoir. In terms of geologic co-sequestration this implies that the addition of CO2 into a reducing carbonate system can result in calcite precipitation, instead of anhydrite as previously thought. Furthermore, it is only limited by the availability of Ca2+ and will therefore not diminish the amount of H2S in the system.

  • Nilsson, Elina
    Luleå University of Technology, Department of Arts, Communication and Education, Education, Language, and Teaching.
    Vilken roll har läroboken i lågstadielärares matematikundervisning?: Arbetsformer och arbetssätt i matematikundervisningen2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Forskning visar att användningen av lärobok i den svenska matematikundervisningen på lågstadiet används i stor utsträckning. Läroboken används mest för att spara tid för läraren, den erbjuder inte eleverna en individanpassad studiegång som de enligt styrdokumenten har rätt till. Vad är det då som påverkar valet att bedriva läroboksbaserad matematikundervisning när det går emot en skola för alla?

    För att ta reda på hur mycket läroboken används i matematikundervisningen och varför lärare väljer att arbeta med just läroboken, användes en blandad datainsamlingsmetod i form av en kvantitativ enkät och en kompletterande enkät. Förslag till andra arbetsformer utöver läroboken lyfts fram i resultatet. Yrkeslivserfarenhet ställs mot användandet av läroboken i matematikundervisningen för att se om det finns något samband eller skillnad med användandet av lärobok och olika år av yrkeslivserfarenheter i skolan. En fenomenografisk ansats har använts för att analysera resultatet.

    Resultatet visar att läroboken har en väldigt stor roll i undervisningen samtidigt som forskare och styrdokumenten går emot den typen av enformigt arbete. Resultatet i studien indikerar att majoriteten av lärarna använder läroboken som arbetssätt större delen av matematikundervisningen. Lärarna väljer för det mesta läroboken eftersom det sparar tid och ger även en trygghet för läraren att luta sig mot i sin matematikundervisning. 

  • Wong, Helene
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Informationssäkerhet inom ramen av GDPR: Utmaningar för personer som arbetar med känsliga personuppgifter2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • Sjödin, David
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Hur individer driver kunskapsabsorption— Internainnovatörer möjliggör teknologiskiften i tillverkningsindustrin2019In: Management of Innovation and TechnologyArticle in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Svensk tillverkande industri möter ett stort omställningstryck till följd av teknologiskiften relaterade till digitalisering, automatisering och elektrifiering. Interna innovatörer har en nyckelroll i omställningen, men möter ofta motstånd när de försöker omsätta ny extern kunskap internt. Vår forskning visar hur individer kan övervinna detta motstånd kan genom att aktivt driva kunskapsabsorption genom olika faser.  

  • Andersson Cederholm, Tilde
    Luleå University of Technology, Department of Arts, Communication and Education.
    Kreativitet och skapande inom skolans ramar: En studie om gymnasieelevers upplevelse av kreativitet och sitt eget skapande inom dans2019Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [sv]

    Den här uppsatsen handlar om hur några gymnasieelever som studerar dans på estetiska programmet upplever kreativitet och eget skapande. Syftet med studien var att undersöka elevernas upplevelse av kreativt skapande inom skolans ramar med fokus på kurserna Dansgestaltning 1 och Koreografi. Det som undersöktes var vilka faktorer som bidrar till att skapa en kreativ miljö och vilka som kan hindra det egna skapandet. Insamlade data bygger på kvalitativa semistrukturerade intervjuer. Sammanlagt gjordes fem enskilda intervjuer med elever från årskurs två och tre på en gymnasieskola i Sverige. Dessa intervjuer transkriberades sedan och analyserades för att hitta olika teman. Temana kodades sedan i olika undergrupper som analyserades. Det som kom fram i resultatet var att eleverna upplevde skapande av dans i skolan som något positivt. När de skapande uppkom känslor som glädje, entusiasm och lugn. Det framkom även vad eleverna behövde för hjälpmedel för att kunna skapa dans. De behövde ha en förförståelse för olika danssteg, en stor lokal med speglar, musik och rätt sinnesstämning. Faktorer som kunde hindra dem var liten yta, klasskamrater, dålig självkänsla, och höga krav på sig själv. Min slutsats var att eleverna ser skapandet som något positivt och de flesta hjälpmedel de behöver finns redan i skolan. Det framkom även att faktorer som hindrar vissa elever i deras skapande kan ha en positiv effekt på andra elevers skapande. Något som också framkom var att eleverna påverkades ytterst lite av betygen.

  • Heffsten, Andreas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Conservation and recreation of development and build environment for embedded systems2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today new technology is rapidly being developed, therefore it becomesdicult for developers to continue development and recreate builds ofsoftware written just a few years ago. Because of this, a quality attributeto make it easier for developers to recreate and continue development ofold systems is needed. The aim of this thesis is to dene what sustain-able system development is and develop a quality attribute for it. Thequality attribute is presented together with tactics, general scenarios andpatterns that can be used to implement the quality attribute on dierentsystems.This is to make it easier for developers to recreate and continuedevelopment of old systems.To dene sustainable system development a number of interviews weredone. These interviews were done with people that are developing soft-ware and with people that are working in the area of improving systemsreproducability. From these interviews sustainable system developmentwas concluded to be dened by how good reproducibility, testability, mod-iability and portability the system has.To prove that the concept for the quality attribute works, the qualityattribute was applied on the system for the ECU Coordinator 8 at Sca-nia. With the aim to implement sustainable system development on thatsystem. The implementation improved the reproducibility and testabilityof the system. But it didn't improve the modiability and portability,which means that the implementation at Scania can still be further im-proved. Some tests were performed where a developer at Scania triedto recreate the system after the implementation of the quality attribute.These tests were successful and an interview with the developer was doneafter the test, where the developer thought that the implementation hada positive eect on sustainable system development. From this the proofof concept for the quality attribute can be seen as successful.