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  • 1.
    Ali, Bako
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Awad, Ali Ismail
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science. Faculty of Engineering, Al Azhar University.
    Cyber and Physical Security Vulnerability Assessment for IoT-Based Smart Homes2018In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 18, no 3, article id 817Article in journal (Refereed)
    Abstract [en]

    The Internet of Things (IoT) is an emerging paradigm focusing on the connection of devices, objects, or “things” to each other, to the Internet, and to users. IoT technology is anticipated to become an essential requirement in the development of smart homes, as it offers convenience and efficiency to home residents so that they can achieve better quality of life. Application of the IoT model to smart homes, by connecting objects to the Internet, poses new security and privacy challenges in terms of the confidentiality, authenticity, and integrity of the data sensed, collected, and exchanged by the IoT objects. These challenges make smart homes extremely vulnerable to different types of security attacks, resulting in IoT-based smart homes being insecure. Therefore, it is necessary to identify the possible security risks to develop a complete picture of the security status of smart homes. This article applies the operationally critical threat, asset, and vulnerability evaluation (OCTAVE) methodology, known as OCTAVE Allegro, to assess the security risks of smart homes. The OCTAVE Allegro method focuses on information assets and considers different information containers such as databases, physical papers, and humans. The key goals of this study are to highlight the various security vulnerabilities of IoT-based smart homes, to present the risks on home inhabitants, and to propose approaches to mitigating the identified risks. The research findings can be used as a foundation for improving the security requirements of IoT-based smart homes.

  • 2.
    Awoyemi, Lawrence
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Influence of prefreezing on the fibre saturation point, sorption and swelling properties of birch (Betula pubescens) wood2006In: International Wood Products Journal, ISSN 0020-3203, Vol. 17, no 4, p. 225-227Article in journal (Refereed)
    Abstract [en]

    Matched samples were obtained from green birch (Betula pubescens) wood. Prefreezing was done at -20°C for 72hours. Both the prefrozen and unfrozen samples were dried and soaked in water for the determination of sorption behavior, swelling properties and fibre saturation point. Prefreezing resulted in 6.7 to 666.7% increase in rate of adsorption, 0 to 13.3% decrease in the rate of desorption, 2.2% decrease in volumetric swelling coefficient and 0.8% decrease in fibre saturation point. However only the change in the rate of water adsorption is statistically significant at 95% confidence level. Since these results were obtained from samples taken from a typical board, more results are required in order to characterise the effects of prefreezing on available stock of Birch wood

  • 3.
    Awoyemi, Lawrence
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Mechanical behaviour of birch (Betula Pubescens) wood under high temperature drying2009In: International Wood Products Journal, ISSN 0020-3203, Vol. 19, no 1, p. 27-30Article in journal (Refereed)
    Abstract [en]

    High temperature drying is employed to reduce the drying time of sawn wood. However the deterioration in mechanical properties associated with it seems to be a major limitation of its use in the seasoning of some wood species. As in conventional drying, both the modulus of elasticity and modulus of rupture increase with decreasing moisture content. High temperature drying does not seem to constitute a meaningful threat to the mechanical properties of this species and hence its use is strongly recommended. The low effect of high temperature drying on this species strongly reinforces the results of the previous studies on other species that the effect of this technique is both species and property dependent.

  • 4.
    Berglund, Andreas
    et al.
    Luleå University of Technology.
    Falk, Anton
    Luleå University of Technology.
    Färm, Felix
    Luleå University of Technology.
    Gerhardsson, Linn
    Luleå University of Technology.
    Göransson, Erik
    Luleå University of Technology.
    Higberg, Ronny
    Luleå University of Technology.
    Jäderblom, Niklas
    Luleå University of Technology.
    Muhl, Christoffer
    Luleå University of Technology.
    Nilsson, Joel
    Luleå University of Technology.
    Petäjävaara, Ellen
    Luleå University of Technology.
    Roos, Elin
    Luleå University of Technology.
    Uttberg, Julia
    Luleå University of Technology.
    Vedin, Elin
    Luleå University of Technology.
    Vikström, Fanny
    Luleå University of Technology.
    Vo, Vivi
    Luleå University of Technology.
    15 koncept för bättre ergonomi: Inom äldreomsorg, fysioterapi, däckmontering och varuhantering2015Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    Den här boken är resultatet av en kurs i ergonomi vid Teknisk design, Luleå tekniska universitet, våren 2015. 15 kursdeltagare har under 10 veckor använt designmetodik och ergonomiska teorier och metoder för att utveckla 15 konceptuella förbättringsförslag baserade på de 4 undersökta kontexterna äldreomsorg, fysioterapi, däckmontering och varuhantering. Fokus för ergonomi inom området teknisk design är att se till att all design, oavsett vilket system det avser, kompletterar människans styrkor och förmågor. Vi ska kort och gott se till att arbetsuppgifter, utrustning, apparater, processer, miljöer och organisationer utformas med människan som utgångspunkt, istället för att tvinga människan att anpassa sig med olika former av överbelastning som möjlig påföljd. För att uppnå detta behöver vi förstå och designa för den variabilitet som är representerad bland oss människor: vi är olika, har olika åldrar, storlek, styrka, kognitiv förmåga, erfarenheter, förväntningar och mål. Att tillämpa ergonomi betyder att studera hur människor interagerar med produkter, processer, miljöer och system för att förbättra dem, dvs. göra dem enklare, säkrare, bekvämare och effektivare att använda. För att kunna göra det behöver vi kunskap om människans förutsättningar och behov. Teknisk design med utgångspunkt och mål i god ergonomi innebär att exempelvis: Att designa produkter och utrustning som är enkla och tillförlitliga att använda med utgångspunkt i kunskap om kognitiv ergonomi, antropometri och belastningsergonomiska och biomekaniska analyserAtt designa säkra och effektiva tillverkningsprocesser med utgångspunkt i kunskap om kognitiv ergonomi och belastningsergonomiska analyserAtt designa organisationer utifrån kunskap om arbetslivsfysiologi och organisationsergonomiAtt designa arbetsuppgifter utifrån kunskap om kognitiv ergonomi, biomekanik och belastningsergonomiska analyserAtt designa enkla och användarvänliga gränssnitt med utgångspunkt i kognitiv ergonomiErgonomisk anpassning av en produkt eller en arbetsmiljö kan exempelvis handla om att se till att människan inte använder kroppen felaktigt. Det kan handla om fysisk belastning när en uppgift utförs, såväl som sensorisk input från olika system eller psykosocial belastning i form av stress. Det handlar om att utveckla kunskaper om människans begränsningar och förmågor, vilket ger bättre förutsättningar att bidra till användarvänliga lösningar. Det i sin tur bidrar till säkerhet och användarvänlighet och i slutändan att alla produkter, system och miljöer i vår omvärld fungerar väl för människan – det är hållbar utveckling om något. I kursen Ergonomi 2 vid civilingenjörsutbildningen Teknisk design, Luleå tekniska universitet, ingår en projektuppgift. Den syftar till att få fördjupad förståelse inom ergonomi genom att tillämpa kunskap och metoder i ett designprojekt för en verklig situation. Våren 2015 omfattade projektuppgiften att enanalys av valfri kontext, med syfte att förstå problem och utmaningar i den miljö, det sammanhang, den situation och för de personer som var berörda. Inledningsvis arbetade kursdeltagarna i grupper bestående av 3-4 personer, för att sedan gå in i en konceptutvecklingsfas individuellt. Det innebar att kursdeltagarna kunde genomföra ergonomiska analyser gemensamt och sedan utveckla konceptuella lösningar på egen hand. Det resulterade i att kursdeltagarna utvecklade tämligen olika lösningar, även om de haft en gemensam utgångspunkt. Bokens kapitel omfattar en beskrivning av respektive kontext följt av de konceptförslag som kursdeltagarna utvecklade. Som lärare är det alltid extra roligt när kursdeltagare är motiverade och engagerade inför projektuppgifter. Vår förhoppning är att det engagemanget ska framgå på följande sidor och att koncepten ska ge inspiration till att förbättra ergonomin i våra vardagsliv. Åsa Wikberg Nilsson, Therese Öhrling, Lars Sundström, Agneta Larsson och Ulrik RöijezonTeknisk design Luleå tekniska universitet, Augusti 2015

  • 5.
    Björling, Marcus
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Minami, Ichiro
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Sundararajan, Bharath
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Environmentally acceptable lubricants for marine applications2018Conference paper (Refereed)
  • 6.
    Blomberg, Jonas
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Mechanical and physical properties of semi-isostatically densified wood2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    When wood is densified through semi-isostatical compression in a Quintus- press at pressures up to 140 MPa, the material properties change. The cells are flattened, size is decreased and shape is changed, as a consequence of this the density is increased. Most properties of native woods are strongly correlated to the density. This is also true for densified wood. To understand the compression mechanisms plastic and elastic strains were studied at different pressures. Strength, density, anatomy and swelling were studied. Some of the methods used were: image analysis, computer tomography scanning (CT), scanning electron microscopy (SEM) and mechanical testing. Data was statistically analysed by linear regression and multivariate statistical methods. A big advantage of using semi-isostatic pressure is that wood of all dimensions, with knots and anomalous wood can be compressed without major checking. As the pressure is mediated through a flexible diaphragm the density becomes homogenous. Plain-sawn wood with inside-face to press-table gets the most homogenous density and the most rectangular shape. Strength is improved by the densification, especially the hardness, the bending and the axial compression strength. At water-soaking densified wood, the cell-shape recovers almost completely. This indicates the non-destructive character of the process. The swelling pressure, that develops when densified wood is restrained from dimensional change and then water-soaked, is more than twice as high as for native wood. The swelling can be reduced by deep impregnation with oil in combination with a surface lacquer.

  • 7.
    Blomberg, Jonas
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Persson, Bengt
    Dalarna University.
    Swelling pressure of semi-isostatically densified wood under different mechanical restraints2007In: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 41, no 5, p. 401-415Article in journal (Refereed)
    Abstract [en]

    Semi-isostatically densified and native wood samples of Scots pine and European birch were soaked in water. The swelling coefficients as well as the swelling pressure, that arose when the specimens were restrained in some way prior to the swelling, were measured using a universal testing machine equipped with a high resolution load-cell and an external extensometer. As densified wood swells, the native structure is almost restored and the swelling pressure became twice as high as for native wood in the most compressed directions (radial for pine and birch). That cell-shape recovery increases the swelling pressure can explain the problems with imbalance in laminated constructions where densified wood is used. The possibility to predict the swelling pressure from basic material properties was evaluated. The correlations between swelling pressure and material properties were strong enough to yield good predictive models

  • 8.
    Blomberg, Jonas
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Persson, Bengt
    Dalarna University, Borlänge.
    Bexell, Ulf
    Dalarna University, Borlänge.
    Effects of semi-isostatic densification on anatomy and cell-shape recovery on soaking2006In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 60, no 1, p. 322-331Article in journal (Refereed)
    Abstract [en]

    Images obtained by scanning electron microscopy (SEM) helped to clarify the question as to how anatomy influences the deformation on compression and the spring-back of densified wood on water soaking. Transverse sections of Norway spruce (Picea abies), Scots pine (Pinus sylvestris), black alder (Alnus glutinosa), Swedish aspen (Populus tremula), European birch (Betula pubescens), European beech (Fagus sylvatica) and pedunculate oak (Quercus robur) were studied. Wood is reinforced with rays in the radial direction and with dense latewood in the tangential direction. When strained radially, rays buckle or tilt tangentially. Softwoods were mainly compressed radially, owing to low number of rays and since latewood is much denser than earlywood. The diffuse-porous hardwoods with low density variation between latewood and earlywood were mainly deformed tangentially, except birch, which has high density at the annual ring border and is mainly compressed radially. The ringporous hardwoods were relatively equally deformed in the radial and tangential directions because of the high number of rays and high latewood density. Moisture-induced springback (shape recovery) was proportional to the degree of compression. Rays remained deformed, which also influenced the surrounding wood. Longitudinal wood cells almost resumed their original shape. Wood with low density and a low degree of compression showed the highest structural recovery. Shearing deformation was particularly pronounced and permanent in woods with high strength anisotropy. Thin-walled and sheared cells, such as earlywood in softwood, tended to crack on compression. Cracks usually stopped at the middle lamella and had a lesser influence on strength properties than for lumen-to-lumen cracks. Copyright

  • 9.
    Bontje, Peter
    et al.
    Department of Occupational Therapy, Graduate School of Human Health Sciences, Tokyo Metropolitan University.
    Asaba, Eric
    Department of Occupational Therapy, Graduate School of Human Health Sciences, Tokyo Metropolitan University.
    Josephsson, Staffan
    Luleå University of Technology, Department of Health Sciences, Health and Rehab. Karolinska institute, Neurobiology Care Sciences and Society, Division of Occupational Therapy, Karolinska institutet, Sektionen för arbetsterapi.
    Balancing struggles with desired results in everyday activities: strategies for elderly persons with physical disabilities2016In: Scandinavian Journal of Caring Sciences, ISSN 0283-9318, E-ISSN 1471-6712, Vol. 30, no 1, p. 154-163Article in journal (Refereed)
    Abstract [en]

    The number of elderly persons with disabilities needing support with everyday activities increasing in Japan and around the world. Yet, engagement in everyday activities can support the quality of their daily life. Despite research focusing on reported meanings of people's actions, there is still limited knowledge on how engagement in everyday activity is enacted along with the meanings of persons’ actions. The aim of the present study was to identify meanings of persons’ actions within everyday activities of elderly Japanese with physical disabilities. Five elderly persons with physical disabilities living in the community participated in this study. Data were gathered by 10 participant observations of everyday activities supplemented with 13 unstructured interviews. Narrative analysis was used to identify meanings of persons’ actions. The analysis identified an overall plot termed ‘balancing struggles with desired results’. This plot illustrated that participants’ and other involved individuals balanced problematic situations with finding situations that accommodated their needs. Meanings of these actions were further identified as three complementary strategies. Two of three strategies aimed to mitigate given problems, one by ‘acting on a plan to achieve one's goals’, the other by ‘taking a step in a preferred direction by capitalising on emerging opportunities’. The third strategy focused on avoiding undesirable experiences by ‘modifying problematic situations’. In conclusion, these findings call for care and rehabilitation providers’ sensitivity to shifting foci of what matters in daily life's situations as well as aligning with persons’ skills, resources and perspectives. Accordingly, the judicious and flexible use of these complementary strategies can enhance elderly persons’ quality of daily living through everyday activities.

  • 10.
    Boonstra, M.J.
    et al.
    Plato International AV, Arnhem.
    Blomberg, Jonas
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Semi-isostatic densification of heat-treated radiata pine2007In: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 41, no 7, p. 607-617Article in journal (Refereed)
    Abstract [en]

    Semi-isostatic densification is a useful method to increase the density and to improve the mechanical properties of fast-grown softwood species like radiata pine. A major disadvantage of this method is the almost complete recovery of the original dimensions when densified wood is exposed to moisture. Heat treatment improves the dimensional stability of wood and might be a useful method to prevent this shape-recovery after densification. However, no or only a limited effect on the shape-recovery was found when densified radiata pine was exposed to moisture.

  • 11.
    Chipp, Kerry
    et al.
    Industrial Economics and Management, KTH, Stockholm.
    Chohan, Raeesah
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Ferreira, Caitlin
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering. Management Studies, University of Cape Town, Cape Town, South Africa.
    Ringas, Astrid
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    British Food Journal: gaining global ground2016In: British Food Journal, ISSN 0007-070X, E-ISSN 1758-4108, Vol. 118, no 1, p. 2-8Article in journal (Refereed)
  • 12.
    Derhamy, Hasan
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Rönnholm, Jesper
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Eliasson, Jens
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Deventer, Jan van
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Protocol interoperability of OPC UA in ServiceOriented Architectures2017In: Proceedings: 2017 IEEE 15th International Conference on Industrial Informatics, INDIN 2017, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 44-50, article id 8104744Conference paper (Refereed)
    Abstract [en]

    Abstract—Industrial Internet of Things covers all aspects ofnetworked intelligent manufacturing systems. This means coveringa wide array of application domains and user requirements.In such scenarios it is not feasible to define a single protocol forall situations. Hence, a multi-protocol approach is required. OPCUA has strong backing from Industry 4.0 as the protocol for theIndustrial Internet of Things. Interoperability of OPC UA hasbeen investigated in the context of migration from legacy andwith protocols such as DPWS. Additionally HTTP and CoAPhave been investigated as possible transport mediums.However, OPC UA interoperability has not been investigatedwithin a multi-protocol settings and no generic protocol translationexists. This paper proposes an OPC UA translator followingthe service translator model proposed in the Arrowhead project.Utilizing a mapping to intermediate format, it can be used alongside CoAP, HTTP and MQTT protocols.

  • 13.
    Feldmann, M.
    et al.
    Rheinisch-Westfälische Technische Hochschule Aachen (RWTH).
    Naumes, J.
    Rheinisch-Westfälische Technische Hochschule Aachen (RWTH).
    Pak, D.
    Rheinisch-Westfälische Technische Hochschule Aachen (RWTH).
    Veljkovic, Milan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Eriksen, J.
    Luleå University of Technology.
    Popa, N.
    ArcelorMittal Belval & Differdange (AM R & D).
    Hechler, O.
    ArcelorMittal Belval & Differdange (AM R & D).
    Seidl, G.
    SSF-Ingenieure AG (SSF).
    Economic and durable design of composite bridges with integral abutments (INTAB+)2012Report (Refereed)
    Abstract [en]

    In the design and construction of bridges, questions of sustainability, maintenance and durability become more and more important for European road administrations in addition to safety and serviceability issues. Therefore integral abutment bridges become highly attractive to designers, constructors and road administrations as they tend to be less expensive to build, easier to maintain and more economical to own over their lifetime. However in Europe less experience in building integral bridges has been gained so far. Therefore in 2005 the European RFCS-projects INTAB has been launched. Within the scope of the project, universities, consulting engineering companies as well as steel producers worked together to develop economic and safe solutions for composite bridges with integral abutments. Significant knowledge has been gained and cost-effective, environmentally friendly and sustainable bridge structures have been developed. Furthermore their durability has been proven to obtain competitive composite bridges for small and medium spans. The outcome of that project was reworked within the scope of the current project to make it available to a larger number of practitioners. To disseminate the knowledge, two workshops have been organised. A design guide was written and translated into German and French. It was completed by a design example as well as CEN-recommendations regarding actual Eurocodes. A software tool was written to help designers to perform some calculations regarding the design of integral abutment bridges.

  • 14.
    Frisk, Nikolina
    et al.
    Luleå University of Technology. Centre for Biocomposites and Biomaterials Processing, Faculty of Forestry, University of Toronto, Toronto, Canada.
    Sain, Mohini
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Centre for Biocomposites and Biomaterials Processing, Faculty of Forestry, University of Toronto, Toronto, Canada.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Centre for Biocomposites and Biomaterials Processing, Faculty of Forestry, University of Toronto, Toronto, Canada.
    Nanocellulose reinforced bio-polyurethane foams as core in sandwich composite panels2017In: ICCM21 Proceedings, ICCM, International Committee on Composite Materials , 2017Conference paper (Refereed)
    Abstract [en]

    The aim of this work was to reinforce bio-polyurethane (BPU) with cellulose nanofibers (CNF) to develop foams suitable for use as core in lightweight composite panels. The nanofibers were prepared using mechanical grinding of bleached carrot juice residue, a cheap and energy efficient process. The prepared foam properties were studied and compared to neat BPU foam properties. The results showed that the CNF reinforced foam had better mechanical properties compared to the neat bio-PU foams and the addition of cellulose nanofibers deceased the cell size and open cell content. Then the foam suitability for composite use was evaluated by manufacturing lightweight sandwich panels using vacuum infusion process with CNF reinforced BPU foam core. Kraft paper was used as a skin and epoxy resin was used as adhesive resin and the composite laminates were prepared using vacuum infusion technique. These nanofiber reinforced core materials resulted in sandwich panels with improved mechanical properties. X-ray tomography showed that the resin did not penetrate into the core but only the foam surface layer. Moreover, the results were evaluated in a material selection process by means of minimizing merit indices. A trend in the behaviour of compressive properties of the foam and flexural properties of the sandwich panels could be established. The addition of small amount of cellulose nanofibers to BPU based foams is leading to a foam which have similar properties as commercial rigid PU foams. © 2017 International Committee on Composite Materials. 

  • 15.
    García Vogel, Andres
    et al.
    Luleå University of Technology. Fiber and Particle Engineering, University of Oulu, Finland.
    Hooshmand, Saleh
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Fiber and Particle Engineering, University of Oulu, Finland.
    All-cellulose composites based on wet-spun cellulose fibers reinforced with cellulose nanocrystals and halloysite nanoclay2017In: ICCM21 Proceedings, ICCM, International Committee on Composite Materials , 2017, article id 3751Conference paper (Refereed)
    Abstract [en]

    The aim of the study was to develop biobased and lightweight composites with unidirectional cellulose fibers without a matrix polymer, so called all-cellulose composites with excellent mechanical properties. Continuous cellulose fibers are currently gaining interest for composite applications and if these fibers can be welded together without using a polymer resin it would result in an environmental friendly composite material. The regenerated fibers were prepared using wet spinning of DMAc/LiCl dissolved cellulose where cellulose nanocrystals (CNC) and halloysitenanotubes (HNT) were used as reinforcements. The loading of the nanomaterials into the dissolved cellulose was between 2 to 20 %. The preliminary results showed that the addition of both CNC and HNT improved the mechanical properties of the regenerated cellulose fibers. It was also seen that low concentration of the nanomaterials was more effective reinforcement than high concentration. Also, the HNT showed slightly better improvement compared to the CNC). The spun nanocomposite fibers were directly wound to a roll after the wet spinning, compression molded to compositesheet and dried. The all-cellulose composites mechanical properties as well as microstructure including nanomaterials orientation in the spun fibers were studied and composites mechanical properties are compared with theoretical models. 

  • 16.
    Geng, Shiyu
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Harila, Maria
    Luleå University of Technology.
    Yao, Kun
    Division of Glycoscience, School of Biotechnology, Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
    Zhou, Qi
    Division of Glycoscience, School of Biotechnology, Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Grafting polyethylene glycol on nanocellulose toward biodegradable polymer nanocomposites2017Conference paper (Refereed)
    Abstract [en]

    In this paper, we investigated the effects of grafting polyethylene glycol on nanocellulose on microstructure, mechanical properties and thermal behaviors of the polylactic acid/nanocellulose composites.

  • 17.
    Geng, Shiyu
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Yao, Kun
    Division of Glycoscience, School of Biotechnology, Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
    Harila, Maria
    Luleå University of Technology.
    Noël, Maxime
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Zhou, Qi
    Division of Glycoscience, School of Biotechnology, Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Aligned biodegradable cellulose-reinforced nanocomposites with high strength and toughness2017Conference paper (Refereed)
    Abstract [en]

    Cellulose, as the most abundant component in wood, has attracted a lot of attention for utilizing it in environmentally-friendly applications to replace the fossil-based materials. Nanocellulose materials with high stiffness and strength, large surface area and biodegradability, are promising reinforcement in polymers. However, the energy consumption of nano-scale isolation of cellulose and the dispersion of nanocellulose materials in the polymers are still challenging for obtaining low-cost and ultra-strong nanocomposites. To overcome these, we focus on investigating the aligned nanocomposites reinforced by a very low cellulose nanofibers (CNF) content (0.1 wt%), and grafting polyethylene glycol (PEG) on CNF was performed to improve the dispersion of them. We found that the alignment can improve mechanical properties of the polylactic acid (PLA)/CNF composites dramatically. With a draw ratio of 8, the strength of the aligned composite reached 320 MPa and the toughness was 30 times enhanced compared to the isotropic material. Much better dispersion of the CNF grafted with PEG in PLA matrix was confirmed by scanning electron microscopy (SEM) compared to the ungrafted CNF, and further supported by the mechanical testing results. Furthermore, the aligned nanocomposites exhibited light scattering behavior indicating they have the potential to be used in optical applications.

  • 18.
    Geng, Shiyu
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Yao, Kun
    Royal Institute of Technology, School of Biotechnology, Stockholm.
    Harila, Maria
    Luleå University of Technology.
    Zhou, Qi
    Royal Institute of Technology, School of Biotechnology, Stockholm.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Fibre and Particle Engineering, University of Oulu, Finland.
    Grafting polyethylene glycol on nanocellulose toward biodegradable polymer nanocomposites2017In: ICCM21 Proceedings, ICCM, International Committee on Composite Materials , 2017Conference paper (Refereed)
    Abstract [en]

    The reinforcing effect of a small amount of nanocellulose materials on biodegradable and polymer-based nanocomposites remains challenging because of the poor dispersion of the nanomaterials and inefficient interaction between the nanocellulose and the polymer matrix. To improve this, we grafted polyethylene glycol (PEG) on nanocellulose and produced composites of 0.1 wt% nanocellulose materials and polylactic acid (PLA) matrix. Here, two types of PEG grafted nanocellulose including TEMPO-oxidized cellulose nanocrystals (TOCNCs) and cellulose nanofibers (TOCNFs), with different lengths and diameters were used as reinforcements, respectively. We investigated the effects of grafting PEG on microstructure, mechanical properties and thermal behaviors of the PLA/nanocellulose composites. It is found that the PEG grafted nanocellulose dispersed better compared to the unmodified nanocellulose in the PLA matrix, and provides higher reinforcing effect that improves the elastic modulus of the nanocomposites compared to the composites with unmodified nanocellulose and ungrafted PEG. However, the glass transition temperature of the nanocomposites was not improved by grafting PEG significantly. We also found that the nanocomposites reinforced by TOCNF exhibited enhanced mechanical and thermal properties compared to those with TOCNCs, which is caused by the higher aspect ratio of the TOCNFs.

  • 19.
    Ghamgosar, Pedram
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Rigoni, Federica
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Gilzad Kohan, Mojtaba
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    You, Shujie
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Morales, Edgar Abarca
    Luleå University of Technology.
    Mazzaro, Raffaello
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Morandi, Vittorio
    Institute for Microelectronics and Microsystems Section of Bologna , National Research Council , Bologna , Italy..
    Almqvist, Nils
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Concina, Isabella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Self-Powered Photodetectors Based on Core-Shell ZnO-Co3O4 Nanowire Heterojunctions2019In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 26, p. 23454-23462Article in journal (Refereed)
    Abstract [en]

    Self-powered photodetectors operating in the UV–visible–NIR window made of environmentally friendly, earth abundant, and cheap materials are appealing systems to exploit natural solar radiation without external power sources. In this study, we propose a new p–n junction nanostructure, based on a ZnO–Co3O4 core–shell nanowire (NW) system, with a suitable electronic band structure and improved light absorption, charge transport, and charge collection, to build an efficient UV–visible–NIR p–n heterojunction photodetector. Ultrathin Co3O4 films (in the range 1–15 nm) were sputter-deposited on hydrothermally grown ZnO NW arrays. The effect of a thin layer of the Al2O3 buffer layer between ZnO and Co3O4 was investigated, which may inhibit charge recombination, boosting device performance. The photoresponse of the ZnO–Al2O3–Co3O4 system at zero bias is 6 times higher compared to that of ZnO–Co3O4. The responsivity (R) and specific detectivity (D*) of the best device were 21.80 mA W–1and 4.12 × 1012 Jones, respectively. These results suggest a novel p–n junction structure to develop all-oxide UV–vis photodetectors based on stable, nontoxic, low-cost materials.

  • 20.
    Hansson, Johan
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Dols Duxans, Jaime
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Svensson, Martin
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Nonlinear Effects of Gravity in Cosmology2018In: Advanced Studies in Theoretical Physics, ISSN 1313-1311, E-ISSN 1314-7609, Vol. 12, no 4, p. 157-172Article in journal (Refereed)
    Abstract [en]

    We consider some nonlinear effects of gravity in cosmology. Possible physically interesting consequences include: non-requirement of dark matter and dark energy, asymmetric gravitational matter-creation, emergent homogeneity/isotropy & asymptotic flatness, resolution of "cosmic coincidence" Omega_m \sim Omega_lambda, effective cutoff of gravitational interaction at the scale of cosmic voids.

  • 21.
    Hridoy, Md Rafiul Sabbir
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Islam, Raihan Ul
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Hossain, Mohammad Shahadat
    Department of Computer Science and Engineering, University of Chittagong.
    Andersson, Karl
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    A Web Based Belief Rule Based Expert System for Assessing Flood Risk2017In: iiWAS'17: Proceedings of the 19th International Conference on Information Integration and Web-based Applications & Services, New York: ACM Digital Library, 2017, p. 434-440Conference paper (Refereed)
    Abstract [en]

    Natural calamities such as flooding, volcanic eruption, tornado hampers our daily life and causes many sufferings. Flood is one of the most catastrophic among the natural calamities. Assessing flood risk helps us to take necessary steps and save human lives. Several heterogeneous factors are used to assess flood risk on the livelihood of an area. Moreover, several types of uncertainties can be associated with each factor. In this paper, we propose a web based flood risk assessment expert system by combining belief rule base with the capability of reading data and generating web-based output. This paper also introduces a generic RESTful API which can be used without writing the belief rule based expert system from scratch. This expert system will facilitate the monitoring of the various flood risk factors, contributing in increasing the flood risk on livelihood of an area. Eventually, the decision makers should be able to take measures to control those factors and to reduce the risk of flooding in an area. Data for the expert system has been collected from a case study area by conducting interviews.

  • 22.
    Hu, Xianfeng
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Studies on Carbothermic Reduction of Chromite in the Presence of FeOx2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Direct chromium alloying by chromite ore is a promising technology for producing Crcontainingsteels, as the ferrochrome production process and the chromium alloying processare integrated into a single step, which has the potential of saving energy and raw materials.In this work Thermogravimetric Analysis experiments and induction furnace experiments (upto 80-kg scale) have been carried out to investigate the carbothermic reduction process ofchromite in the presence of FeOx (iron, mill scale or magnetite). The aims are to investigatethe effect of FeOx on the carbothermic reduction of chromite and to explore the potential ofdirectly alloying steel with chromium by the designed alloying precursor ‘chromite ore +FeOx + carbonaceous material’.The results from the Thermogravimetric Analysis experiments show that FeOx can enhancethe carbothermic reduction of chromite and the enhancing effect increases when increasedamounts of FeOx are added to the chromite. The enhancing effect is attributed to the presenceof added metallic iron or the metallic iron reduced from mill scale or magnetite, which candecrease the activity of chromium by having chromium dissolve in the iron in situ. The resultsfrom the induction furnace experiments show that the steel can be directly alloyed withchromium by using the designed alloying precursor ‘chromite ore + mill scale + petroleumcoke’ and the chromium yield from chromite ore increases when increased amounts of millscale are added to the alloying precursor.The designed alloying precursor, on one hand, can be potentially used to directly alloy steelwith chromium in the Electric Arc Furnace steelmaking process and, on the other hand, can bepotentially used to produce Cr pre-alloyed iron powder or Cr pre-alloyed Direct Reduced Ironby the solid-state reduction process. The proposed applications have the potential to improvethe raw materials efficiency and energy efficiency.

  • 23.
    Hu, Xianfeng
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering. Process Metallurgy Department, Swerea MEFOS AB, Luleå, Sweden.
    Yang, Qixing
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Sundqvist-Ökvist, Lena
    Swerea MEFOS AB, Luleå tekniska universitet, SSAB Tunnplåt AB, LKAB.
    Björkman, Bo
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Thermal Analysis Study on the Carbothermic Reduction of Chromite Ore with the Addition of Mill Scale2016In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 87, no 5, p. 562-570Article in journal (Refereed)
    Abstract [en]

    This paper presents a fundamental study on the carbothermic reduction of chromite ore with the addition of mill scale, which forms the basis for designing an alloying precursor, “chromite ore + mill scale + carbon,” for direct chromium alloying. The reduction of chromite ore by petroleum coke with or without the addition of mill scale is investigated by Thermogravimetric Analysis (TGA) under non-isothermal conditions (from room temperature to 1823 K) in the argon atmosphere; the fractional reduced samples were characterized by SEM/EDS and XRD analyses. The experimental results show that the mill scale in the alloying mixture is reduced to high active iron first and disseminated around the chromite ore particles; the reduction of chromite ore is enhanced with the addition of mill scale especially at temperatures higher than 1623 K, and the enhancing effect increased with increasing mill scale addition. The enhancing effect is attributed to the presence of molten Fe–C alloy in the vicinity of chromite ore, which can decrease the thermodynamic activity of chromium by having chromium in situ dissolve into the melt.

  • 24.
    Jia, Yu
    et al.
    Department of Environment and Minerals Resources, Greenland Institute of Nature Resources.
    Ehlert, Ludwig
    Ramboll Sverige AB.
    Wahlskog, Cecilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lundberg, Angela
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Maurice, Christian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Water quality of stormwater generated from an airport in a cold climate, function of an infiltration pond, and sampling strategy with limited resources2018In: Environmental Monitoring & Assessment, ISSN 0167-6369, E-ISSN 1573-2959, Vol. 190, no 1, article id 4Article in journal (Refereed)
    Abstract [en]

    Monitoring pollutants in stormwater discharge in cold climates is challenging. An environmental survey was performed by sampling the stormwater from Luleå Airport, Northern Sweden, during the period 2010-2013, when urea was used as a main component of aircraft deicing/anti-icing fluids (ADAFs). The stormwater collected from the runway was led through an oil trap to an infiltration pond to store excess water during precipitation periods and enhance infiltration and water treatment. Due to insufficient capacity, an emergency spillway was established and equipped with a flow meter and an automatic sampler. This study proposes a program for effective monitoring of pollutant discharge with a minimum number of sampling occasions when use of automatic samplers is not possible. The results showed that 90% of nitrogen discharge occurs during late autumn before the water pipes freeze and during snow melting, regardless of the precipitation during the remaining months when the pollutant discharge was negligible. The concentrations of other constituents in the discharge were generally low compared to guideline values. The best data quality was obtained using flow controlled sampling. Intensive time-controlled sampling during late autumn (few weeks) and snow melting (2 weeks) would be sufficient for necessary information. The flow meters installed at the rectangular notch appeared to be difficult to calibrate and gave contradictory results. Overall, the spillway was dry, as water infiltrated into the pond, and stagnant water close to the edge might be registered as flow. Water level monitoring revealed that the infiltration capacity gradually decreased with time.

  • 25.
    Jia, Yu
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Stenman, David
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Mäkitalo, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Maurice, Christian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Use of rest products as additive in tailings paste for the mitigation of ARD: Effect of green liquor dregs and fly ash addition on geotechnical stabilization of tailings2012In: Proceedings of the 8th International Conference on the Environmental and Technical Implications of Construction with Alternative Materials: WASCON 2012 Conference proceedings / [ed] M. Arm; C. Vandecasteele; J. Heynen; P. Suer; B. Lind, ISCOWA , 2012Conference paper (Refereed)
    Abstract [en]

    This study focuses on the effect of green liquor dregs (GLD) and fly ash (FA) on geotechnical stabilization of tailings, using shear strength test.The objectives were to evaluate thickening of tailings using GLD to paste to improve its water retention and to reduce waste percolation, to identify optimal proportion of additives regarding geotechnical stabilization of tailings, and to study the role of FA in the decrease of porosity and thus to reduce oxygen diffusion via hardening process.The results showed that GLD is a potential material for tailings stabilization by decreasing water percolation and improving water retention property. However, the paste of GLD amended tailings withstands low shear strength. The addition of FA to the paste greatly improves shear strength which is up to 2-3 times higher. Moreover, the fly ash hardening process effectively reinforces the strength of GLD amended tailings paste. Longer curing period (3 months) for specimens leads to up to 2-3 folds higher strength compared to that of 1 month. Hydraulic conductivity is reduced as a result of GLD and FA addition, since the porosity of the tailings decreased. If reduced porosity, improved water retention capacity and no cracks are ensured in the tailings, oxygen diffusion can be limited.

  • 26.
    Jonsson, Linnea
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Innovation and Design.
    Thorgren, Sara
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Innovation and Design.
    Trainee programs: an emerging model on psychological contract reciprocity2017In: Personnel review, ISSN 0048-3486, E-ISSN 1758-6933, Vol. 46, no 8, p. 1738-1754Article in journal (Refereed)
    Abstract [en]

    Purpose

    The purpose of this paper is to develop a deeper understanding of the organization-trainee relationship through a psychological contract lens, by exploring the psychological contract between the trainee and organization during and after the program and what factors may account for contract reciprocity.

    Design/methodology/approach

    Inductive qualitative study design.

    Findings

    Data suggested that factors accounting for contract reciprocity during the program included: trainees’ responsibilities, trainees’ personal and professional development, trainees’ commitment, trainees’ delivery, and managerial and supervisory support. Factors identified accounting for contract reciprocity after individuals completed the program were: career opportunities, future-oriented dialogue between former trainees and managers, wage-setting, job tasks, and working conditions.

    Originality/value

    This exploratory research is original in that it identifies different factors accounting for the reciprocity during and after the program, and how this may be particularly relevant when talents are recruited externally to specifically participate in the program.

  • 27.
    Kasai, Y.
    et al.
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Sagawa, H.
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Kreyling, D.
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Dupuy, E.
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Baron, P.
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Mendrok, Jana
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Suzuki, K.
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Sato, T.O.
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Nishibori, T.
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Mizobuchi, S.
    Japan Aerospace Exploration Agency (JAXA), Tsukuba.
    Kikuchi, K.
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Manabe, T.
    Osaka Prefecture University, Naka, Sakai.
    Ozeki, H.
    Toho University, Funabashi, Chiba.
    Sugita, T.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Fujiwara, M.
    Toho University, Funabashi, Chiba.
    Irimajiri, Y.
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Walker, K.A.
    University of Toronto.
    Bernath, P.F.
    Old Dominion University, Norfolk, Virginia.
    Boone, C.
    University of Waterloo.
    Stiller, G.
    Forschungszentrum Karlsruhe, Institut für Meteorologie und Klimaforschung Karlsruhe.
    Clarmann, T. von
    Forschungszentrum Karlsruhe, Institut für Meteorologie und Klimaforschung Karlsruhe.
    Orphal, J.
    Forschungszentrum Karlsruhe, Institut für Meteorologie und Klimaforschung Karlsruhe.
    Urban, J.
    Chalmers University of Technology.
    Murtagh, D.
    Chalmers University of Technology.
    Llewellyn, E.J.
    Institute of Space and Atmospheric Studies, University of Saskatchewan.
    Yasui, M.
    National Institute of Information and Communications Technology, 4-2-1 Nukui-kitamachi, Koganei.
    Validation of stratospheric and mesospheric ozone observed by SMILES from International Space Station2013In: Atmospheric Measurement Techniques, ISSN 1867-1381, E-ISSN 1867-8548, Vol. 6, no 9, p. 2311-2338Article in journal (Refereed)
    Abstract [en]

    We observed ozone (O3) in the vertical region between 250 and 0.0005 hPa (~ 12–96 km) using the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the Japanese Experiment Module (JEM) of the International Space Station (ISS) between 12 October 2009 and 21 April 2010. The new 4 K superconducting heterodyne receiver technology of SMILES allowed us to obtain a one order of magnitude better signal-to-noise ratio for the O3 line observation compared to past spaceborne microwave instruments. The non-sun-synchronous orbit of the ISS allowed us to observe O3 at various local times. We assessed the quality of the vertical profiles of O3 in the 100–0.001 hPa (~ 16–90 km) region for the SMILES NICT Level 2 product version 2.1.5. The evaluation is based on four components: error analysis; internal comparisons of observations targeting three different instrumental setups for the same O3 625.371 GHz transition; internal comparisons of two different retrieval algorithms; and external comparisons for various local times with ozonesonde, satellite and balloon observations (ENVISAT/MIPAS, SCISAT/ACE-FTS, Odin/OSIRIS, Odin/SMR, Aura/MLS, TELIS). SMILES O3 data have an estimated absolute accuracy of better than 0.3 ppmv (3%) with a vertical resolution of 3–4 km over the 60 to 8 hPa range. The random error for a single measurement is better than the estimated systematic error, being less than 1, 2, and 7%, in the 40–1, 80–0.1, and 100–0.004 hPa pressure regions, respectively. SMILES O3 abundance was 10–20% lower than all other satellite measurements at 8–0.1 hPa due to an error arising from uncertainties of the tangent point information and the gain calibration for the intensity of the spectrum. SMILES O3 from observation frequency Band-B had better accuracy than that from Band-A. A two month period is required to accumulate measurements covering 24 h in local time of O3 profile. However such a dataset can also contain variation due to dynamical, seasonal, and latitudinal effects

  • 28.
    Kumpiene, Jurate
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Xu, Jingying
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Bäckström, Anna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Arsenic leaching in landfilled soil2012In: Abstract proceedings of 7th Intercontinental Landfill Research Symposium: Södra Sunderbyn, June 25th to 27th, 2012 / [ed] Anders Lagerkvist, Luleå: Luleå tekniska universitet, 2012, p. 87-Conference paper (Refereed)
  • 29.
    Leiro, Alejandro
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Kankanala, Anusha
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Vuorinen, Esa
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Prakash, Braham
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Tribological behaviour of carbide-free bainitic steel under dry rolling/sliding conditions2011In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 273, no 1, p. 2-8Article in journal (Refereed)
    Abstract [en]

    The dry rolling/sliding wear behaviour of Si alloyed carbide free bainitic steel austempered at different temperatures and sliding distances has been evaluated. 60SiCr7 spring steel samples were austempered in a salt bath maintained at 250, 300 and 350 °C respectively for 1 h. Rolling with 5% sliding wear tests were performed using self mated discs for three different test cycles, namely 6000, 18000 and 30000 cycles. The aim was to study the wear performance of the 60SiCr7 steel with a carbide-free microstructure containing different amounts of retained austenite. An in-depth microstructural characterization has been carried out before and after the wear tests in order to link the wear behaviour to the microstructure of each sample. The wear resistance has been expressed by means of the specific wear calculated from the mass loss after the tests. The worn surfaces were analyzed by scanning electron microscopy and X-ray diffraction. Micro-hardness profiles were also obtained in order to analyze strain-hardening effects beneath the contact surfaces. The results indicate that the material with highest hardness—the one austempered at 250 °C—exhibited the lowest wear rate in every case. It was also observed that the hardness increment and thickness of the hardened layer increases with increasing the austempering temperature and number of test cycles. Finally, the results appear to indicate that the initial roughness of the samples has no major effect in the wear rate of the samples above 2500 cycles. The higher wear performance of the sample austempered at 250 °C has been attributed to its superior mechanical properties provided by its finer microstructure. It has been evidenced that all samples undergo the TRIP phenomenon since, after wear; no retained austenite could be detected by XRD.

  • 30.
    Lucchese, Riccardo
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Olsson, Jesper
    Luleå University of Technology.
    Ljung, Anna-Lena
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Garcia-Gabin, Winston
    ABB Corporate Research, Västerås.
    Varagnolo, Damiano
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Energy savings in data centers: A framework for modelling and control of servers’ cooling2017In: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, no 1, p. 9050-9057Article in journal (Refereed)
    Abstract [en]

    Aiming at improving the energy efficiency of air cooled servers in data centers, we devise a novel control oriented, nonlinear, thermal model of the servers that accounts explicitly for both direct and recirculating convective air flows. Instrumental to the optimal co-design of both geometries and cooling policies, we propose an identification methodology based on Computational Fluid Dynamics (CFD) for a generic thermal network of m fans and n electronic components. The performance of the proposed modelling framework is validated against CFD measurements with promising results. We formalize the minimum cooling cost control problem as a polynomially constrained Receding Horizon Control (RHC) and show, in-silico, that the resulting policy is able to efficiently modulate the cooling resources in spite of the unknown future computational and electrical power loads.

  • 31.
    Mu, Liwen
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements. Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Wu, Jian
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Matsakas, Leonidas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Chen, Minjiao
    Vahidi, Alireza
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rova, Ulrika
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Christakopoulos, Paul
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Zhu, Jiahua
    Intelligent Composites Laboratory, Department of Chemical and Biomolecular Engineering, The University of Akron.
    Shi, Yijun
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lignin from Hardwood and Softwood Biomass as a Lubricating Additive to Ethylene Glycol2018In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 23, no 3, article id 537Article in journal (Refereed)
    Abstract [en]

    Ethylene glycol (EG)-based lubricant was prepared with dissolved organosolv lignin from birch wood (BL) and softwood (SL) biomass. The effects of different lignin types on the rheological, thermal, and tribological properties of the lignin/EG lubricants were comprehensively investigated by various characterization techniques. Dissolving organosolv lignin in EG results in outstanding lubricating properties. Specifically, the wear volume of the disc by EG-44BL is only 8.9% of that lubricated by pure EG. The enhanced anti-wear property of the EG/lignin system could be attributed to the formation of a robust lubrication film and the strong adhesion of the lubricant on the contacting metal surface due to the presence of a dense hydrogen bonding (H-bonding) network. The lubricating performance of EG-BL outperforms EG-SL, which could be attributed to the denser H-bonding sites in BL and its broader molecular weight distribution. The disc wear loss of EG-44BL is only 45.7% of that lubricated by EG-44SL. Overall, H-bonding is the major contributor to the different tribological properties of BL and SL in EG-based lubricants.

  • 32.
    Mäki, Rikard
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Ganemi, B.
    Statoil Lubricants, Stockholm.
    Flores, R.T.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Olsson, R.
    Haldex Traction Systems AB.
    Wet clutch transmission fluid for AWD differentials: influence of lubricant additives on friction characteristics2006In: Automotive and industrial lubrication: 15th International Colloquium Tribology, January 17 - 19, 2006 ; [book of synopses 2006] / [ed] Wilfried J. Bartz, Ostfildern: Techn. Akad. Esslingen , 2006, p. 35-Conference paper (Refereed)
    Abstract [en]

    A study on the influence of base oils on friction properties was carried out. The effects of additive interactions must be considered but were hard to predict. This was most notable with EP additives that were hard to combine with other additives without compromising the anti-shudder properties of the clutch. The developed fluid showed that it is feasible to combine anti-shudder properties and hypoid gear lubrication abilities in one fluid. Good anti-shudder properties were realized despite high concentrations of EP additives. This is an abstract of a paper presented at the 15th International Colloquium Tribology-Automotive and Industrial Lubrication (Ostfildern, Germany 1/17-19/2006).

  • 33.
    Mäkitalo, Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Stenman, David
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. WSP Samhällsbyggnad.
    Ikumapayi, Fatai
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Boliden Mineral AB.
    Maurice, Christian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. Ramböll Sverige AB.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    An Evaluation of Using Various Admixtures of Green Liquor Dregs, a Residual Product, as a Sealing Layer on Reactive Mine Tailings2016In: Mine Water and the Environment, ISSN 1025-9112, E-ISSN 1616-1068, Vol. 35, no 3, p. 283-293Article in journal (Refereed)
    Abstract [en]

    Green liquor dregs (GLD), a residual product from sulfate paper mills, was blended with tailings, fly ash, and bark sludge with the aim of improving the material’s physical properties so that it could function as a sealing layer in dry covers on sulfidic mine waste. Geotechnical and geochemical investigations, including weathering cell tests, were carried out on GLD with admixtures to assess their effectiveness. Due to its alkaline character, GLD was shown to have the potential to improve leachate quality by decreasing metal mobility when blended with tailings. The admixtures showed favorable sealing layer properties such as high water retention capacity and low hydraulic conductivity. However, caution must be exercised when the dregs are blended with tailings containing large amounts of As and Mo, since increased leaching of these elements may be expected.

  • 34.
    Normark, Carl Jörgen
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Innovation and Design.
    Parnes, Peter
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Ek, Robert
    Luleå University of Technology, Department of Arts, Communication and Education, Music and dance.
    Andersson, Harald
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    The Extended Clarinet2016Conference paper (Refereed)
  • 35.
    Parding, Karolina
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Sehlstedt, Therese
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Johansson, Anna
    Luleå University of Technology.
    Berg-Jansson, Anna
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Jakobsson, Mats
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Lärares arbetsvillkor i kontexten av marknadisering, privatisering, val och konkurrens: – beskrivande kvantitativa data2018Report (Other academic)
  • 36.
    Pelcastre, Leonardo
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Hardell, Jens
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Rolland, Anthony
    Prakash, Braham
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Influence of microstructural evolution of Al-Si coated UHSS on its tribological behaviour against tool steel at elevated temperatures2016In: Journal of Materials Processing Technology, ISSN 0924-0136, E-ISSN 1873-4774, Vol. 228, p. 117-124Article in journal (Refereed)
    Abstract [en]

    The usage of the hot stamping process is of great importance due to the high demands for production of ultra-high strength steels (UHSS). An Al-Si coating is normally applied to the steel to prevent decarburisation and scaling during heating and to improve the corrosion resistance of the final component. During heating, the Al and the Si from the coating combine with the Fe from the steel substrate to form hard intermetallic phases. Little is known about the influence of the heating conditions on the tribological behaviour of the Al-Si coating during interaction with tool steels. The present work investigated different heat treatment parameters and the influence they had on the microstructure of the coating and the galling behaviour. With low alloying temperatures (700˚C), severe galling occurred and increasing the alloying temperature to 900˚C resulted in almost negligible material transfer. The reduction in galling was associated to the development of Fe2Al5 and FeAl2 at the surface.

  • 37.
    Rigaki, Maria
    et al.
    Luleå University of Technology.
    Elragal, Ahmed
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Adversarial deep learning against intrusion detection classifiers2017In: CEUR Workshop Proceedings / [ed] Kott A.,Pechoucek M., CEUR-WS , 2017, Vol. 2057, p. 35-48Conference paper (Refereed)
    Abstract [en]

    Traditional approaches in network intrusion detection follow a signature-based approach, however the use of anomaly detection approaches and machine learning techniques have been studied heavily for the past twenty years. The continuous change in the way attacks are appearing, the volume of attacks, as well as the improvements in the big data analytics space, make machine learning approaches more alluringthan ever. The intention of this paper is to show that using machine learning in the intrusion detection domain should be accompanied with an evaluation of its robustness against adversaries. Several adversarial techniques have emerged lately from the deep learning research, largely in the area of image classification. These techniques are based on the idea of introducing small changes in the original input data in order to make a machine learning model to misclassify it. This paper follows a big data analytics methodology and explores adversarial machine learning techniques that have emerged from the deep learning domain, against machine learning classifiers used for network intrusion detection. We look at several well-known classifiers and study their performance under attack over several metrics, such as accuracy, F1-score and receiver operating characteristic. The approach used assumes no knowledge of the original classifier and examines both general and targeted misclassification. The results showthat using relatively simple methods for generating adversarial samples it is possible to lower the detection accuracy of intrusion detection classifiers as much as 27%. Performance degradation is achieved using a methodology that is simpler than previous approaches and it requires only 6.14% change between the original and the adversarial sample, making it a candidate for a practical adversarial approach. 

  • 38.
    Sandberg, Karin
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Degradation of Norway spruce (Picea abies) heartwood and sapwood during 5.5 years' above-ground exposure2008In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 3, no 3-4, p. 83-93Article in journal (Refereed)
    Abstract [en]

    Differences in durability between heartwood and sapwood of Norway spruce [Picea abies (L.) Karst.] were investigated to determine wood qualities most favourable for use in outdoor constructions above ground. Trees grown on sites with either good or poor access to water were used. Seventy-eight specimens measuring 2050300 mm3 separated into heartwood and sapwood, half untreated, half painted, were exposed horizontally outdoors above ground for 5.5 years with the pith side up and the bark side down. Crack length and crack number were measured. Fungus growth and surface changes were visually estimated. Fungus type was determined by microscopic analysis. The main finding was that spruce heartwood had fewer and shorter cracks and less surface-discolouring fungus growth than sapwood. This was valid for both painted and untreated wood. After 2 years' exposure, the cracks in sapwood (upper surface) were more than three times longer and about five times more numerous than in heartwood for both painted and untreated boards. Microscopic study showed that surface discoloration was due mainly to Aureobasidium pullulans, together with a few other discolouring fungi. After 5.5 years, initial decay was established on the surface and in the end grain of four untreated test objects.

  • 39.
    Sandberg, Karin
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Sterley, Magdalena
    Växjö university.
    Separating Norway spruce heartwood and sapwood in dried condition with near-infrared spectroscopy and multivariate data analysis2009In: European Journal of Forest Research, ISSN 1612-4669, E-ISSN 1612-4677, Vol. 128, no 5, p. 475-481Article in journal (Refereed)
    Abstract [en]

    Norway spruce [Picea abies (L.) Karst.] heartwood and sapwood have differing wood properties, but are similar in appearance. An investigation was made to see whether near-infrared spectroscopy (NIRS) could be used with multivariate statistics for separation between heartwood and sapwood in dry state on tangential longitudinal surfaces. For classification of wood into sapwood and heartwood, partial least square (PLS) regression was used. Orthogonal signal correction (OSC) filtering was used on the spectra. This study shows that a separation of sapwood and heartwood of spruce is possible with NIR spectra measured in a laboratory environment. The visible-wavelength spectra have significant influence on the predictive power of separation models between sapwood and heartwood of spruce. All 44 specimens in the calibration set were correctly classified into heartwood and sapwood. Validation of the model was done with a prediction set of 16 specimens, of which one was classified incorrectly.

  • 40.
    Soria-Salinas, Álvaro
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Wittman, Philipp
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Zorzano Mier, Maria-Paz
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Martin-Torres, Javier
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Wind Retrieval Measurements for the Mars Surface Exploration2016Conference paper (Other academic)
    Abstract [en]

    We present a novel method to quantify the heat transfer coefficient h at the near environment of a spacecraft operating under Mars surface atmospheric conditions. As part of the scientific instruments of the ExoMars 2018 Surface Platform, the HABIT (HabitAbility: Brines, Irradiance and Temperature) instrument will be operating on Mars surface in order to establish the habitability of the landing site. By resolving the energy balance equation in temperatures over the three HABIT Air Temperature Sensor (ATS), we will retrieve the fluid temperature Tf and the known as m-parameter directly related with the heat transfer coefficient and sensitive to variations in wind density and velocity field

  • 41.
    Stjernberg, Jesper
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. LKAB.
    Olivas-Ogaz, M.A.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Antti, Marta-Lena
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Ion, John
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Lindblom, B.
    LKAB.
    Laboratory scale study of the degradation of mullite/corundum refractories by reaction with alkali-doped deposit materials2013In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 39, no 1, p. 791-800Article in journal (Refereed)
    Abstract [en]

    Refractory bricks based on mullite and corundum, commonly used in rotary kilns for iron ore pellet production, and depositmaterial from an iron ore pellet production kiln, were used in laboratoryscale tests to investigate refractory/depositreactions and the infiltration of deposit components into the refractory bricks. The materials tested were in both monolithic form and in the form of powder. Alkali metal carbonates (containing sodium and potassium) were used as corrosive agents, to increase reaction kinetics. The morphological changes and active chemical reactions at the refractory/deposit interface in the samples were characterized by scanning electron microscopy. X-ray diffraction showed that alkali metals react with the mullite in the bricks, this being more pronounced in the case of sodium than potassium. Phases such as nepheline (Na2O·Al2O3·2SiO2), kalsilite and kaliophilite (both K2O·Al2O3·2SiO2), and leucite (K2O·Al2O3·4SiO2) were formed as a consequence of reactions between alkali metals and the refractory bricks. The formation of these phases causes volume expansions of between 20% and 25% in the brick materials, which accelerate degradation.

  • 42.
    Stålnacke, Peter
    et al.
    Luleå University of Technology.
    Waara, Peter
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Ungdomsforskning i Barentsregionen2006Report (Other academic)
  • 43.
    Sundqvist, Bror
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Westermark, Ulla
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Eriksson, Gustav
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Cellulose degradation during hydrothermal treatment of birch wood (Betula pubescens Ehrh.)2006In: Cellulose Chemistry and Technology, ISSN 0576-9787, Vol. 40, no 3-4, p. 217-221Article in journal (Refereed)
    Abstract [en]

    Study of cellulose degradation during wood's heat treatment showed a considerable degradation in both commercially and laboratory heat-treated wood samples, probably due to the low pH induced by the heat treatment. Experimental series were performed for investigating cellulose degradation in birch wood, at different pH levels and times, during heat treatments performed at pH values of 4, 7 and 10, for 3 and 6 hours at 180°C. The results show that the selected span of pH and time of treatment clearly affects the size of the cellulose molecules. Study of cellulose degradation involved intrinsic viscosity measurements on α-cellulose from the samples. As a result of heat treatment, viscosity drops from 1430 mL/g (untreated wood) to less than or equal 700 mL/g and less than or equal 350 mL/g, for durations of 3 and 6 hours, respectively. The wood buffered in an aqueous solution at pH 4 showed a drop in intrinsic viscosity around 880 mL/g, while a sample of commercial "thermowood" yielded an intrinsic viscosity of 732 mL/g. For neutral and alkaline pH values, the drop in viscosity is considerably lower. At pH values of 7 and 10, a 3 hr treatment had almost no effect on the degree of polymerisation, while a 6 hr treatment gave intrinsic viscosities around 1000 mL/g and 1216 mL/g, respectively. There is a distinct relation between cellulose's molecular size and wood's strength properties. The decrease in cellulose length in unbuffered systems may affect the strength properties of the treated wood. The experiments show that pH is an important factor to consider.

  • 44.
    Sviridova, Olga
    et al.
    Luleå University of Technology.
    Gard, Gunvor
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Michaelson, Peter
    Luleå University of Technology, Department of Health Sciences, Health and Rehabilitation.
    Predictors for return to work after multimodal rehabilitation in persons with persistent musculoskeletal pain2018In: Edorium Journal of Disability and Rehabilitation, ISSN 2456-8392, Vol. 4, no 1, article id 100038D05SO2018Article in journal (Refereed)
    Abstract [en]

    Aims: To identify factors explaining return to work (RTW) 12 months after a multimodal rehabilitation (MMR) intervention in the REHSAM II project.

    Methods: The present study is a secondary assessment of the data from the randomized controlled trial REHSAM II. A total of 97 participants with persistent musculoskeletal pain were randomly allocated to MMR + web-based education or only MMR. The subjects were followed from baseline to 12 months. The baseline variables from the outcome measures were used to identify predictors. The associations between the dependent variable (i.e., RTW) and independent variables (i.e., baseline variables) were analyzed with univariate and multiple logistic regression models.

    Results: The univariate regression analyses showed that pain and disability level, the capacity to perform a task in relation to pain, hospital and psychiatric care, medication for insomnia, catastrophizing, self-assessed work ability compared with lifetime best, satisfaction with life, ability for coping and controlling work situation, ability for coping with life outside work, and sense of responsibility for managing health condition were significantly associated with RTW. In the final multiple regression model, RTW was predicted by the Örebro Musculoskeletal Pain Screening Questionnaire (ÖMPSQ score) (p=0.003, OR=0.961) and EuroQol (EQ-5D index) (p=0.017, OR=7.283)

  • 45.
    Söderholm, Kristina
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Larsson, Linus
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Söderholm, Patrik
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Managing the 1970s energy crises in a state-owned mining company: strategies pursued by the Swedish iron ore producer LKAB2018In: Mineral Economics, ISSN 2191-2203, E-ISSN 2191-2211, Vol. 31, no 1-2, p. 179-190Article in journal (Refereed)
    Abstract [en]

    In this paper, we analyze the strategies adopted by the Swedish state-owned iron ore mining producer LKAB in response to the 1970s energy crises, i.e., soaring energy input expenses in combination with stagnating demand for iron ore. The analysis builds on a unique empirical material, e.g., minutes from board meetings, over an extended time period. This permits in-depth analyses of the two main strategies pursued by LKAB at the time: (a) securing energy supplies (as well as output sales) through upstream investments in uranium and coal mining; and (b) engaging in own R&D to enable energy-saving measures and product development. While the LKAB experiences tend to support the notion that investments supporting broader societal goals, although at the expense of firm productivity, may be likely in the presence of strong state government involvement, they also show that state-owned mineral enterprises can be highly innovative and competitive following investments in internal R&D. Specifically, LKAB’s R&D contributed to significant product development and energy savings, the latter occurring both in the company’s own pelletizing process as well as in the processes of key customers (i.e., the steel companies). The paper concludes by highlighting a number of important lessons for contemporary energy transitions in the process industries.

  • 46.
    Söderholm, Patrik
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Hellsmark, Hans
    Chalmers University of Technology, Environmental Systems Analysis, Gothenburg, Sweden.
    Frishammar, Johan
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering. Stockholm School of Economics, House of Innovation, Stockholm, Sweden.
    Hansson, Julia
    Chalmers University of Technology, Maritime Environmental Sciences, Gothenburg, Sweden. IVL Swedish Environmental Research Institute, Gothenburg, Sweden.
    Mossberg, Johanna
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science. RISE Research Institutes of Sweden, RISE Bioeconomy, Gothenburg, Sweden.
    Sandström, Annica
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Technological development for sustainability: The role of network management in the innovation policy mix2019In: Technological forecasting & social change, ISSN 0040-1625, E-ISSN 1873-5509, Vol. 138, p. 309-323Article in journal (Refereed)
    Abstract [en]

    Despite the key role of actor networks in progressing new sustainable technologies, there is a shortage of conceptual knowledge on how policy can help strengthen collaborative practices in such networks. The objective of this paper is to analyze the roles of such policies – so-called network management – throughout the entire technological development processes. The analysis draws on the public management and sustainability transitions literatures, and discusses how various network characteristics could affect the development of sustainable technologies, including how different categories of network management strategies could be deployed to influence actor collaborations. The paper's main contribution is an analytical framework that addresses the changing roles of network management at the interface between various phases of the technological development process, illustrated with the empirical case of advanced biorefinery technology development in Sweden. Furthermore, the analysis also addresses some challenges that policy makers are likely to encounter when pursuing network management strategies, and identifies a number of negative consequences of ignoring such instruments in the innovation policy mix. The latter include inefficient actor role-taking, the emergence of small, ineffective and competing actor networks in similar technological fields, and a shortage of interpretative knowledge.

  • 47.
    Thordin, Gustaf
    et al.
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Fransson, Adam
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Prevalence of Musculoskeletal Pain and Generalised Joint Hypermobility among Jazz Musicians in Swedish Big Bands2015In: Musician's Health and Performance. 2nd Conference (MHPC2015): Book of Abstracts, Odense, 2015, article id 50Conference paper (Refereed)
    Abstract [en]

    Aims: The aim of this study was to investigate the prevalence of musculoskeletal pain and generalised joint hypermobility (GJH) among professional jazz musicians in Swedish big bands and to investigate possible associations between GJH and pain.Methods: An existing health questionnaire developed for professional orchestra musicians, including the 5-part questionnaire for GJH [1], the standardised Nordic questionnaire for musculoskeletal pain disorders [2] and additional specific questions about playing related musculoskeletal pain (PRMD), was presented to jazz musicians employed at three professional Swedish big bands. Thirty musicians (86%) participated, aged 45 (±10) years, only two (7%) of the participants were women.Results: The total prevalence of musculoskeletal pain within the previous 12 months was 91%, while total point prevalence was 47%. The neck, lower back and left shoulder were the most common regions for both 12 month and point prevalence among the musicians.The total prevalence of PRMD, defined as pain or related symptoms that interferes with ability to play, within the last 7 days was 27%. Most common regions were the neck and left shoulder, followed by low back and left hand.Twenty-seven percent reported GJH, and binary logistic regression analyses showed significant association between GJH and left hand pain within the last 12 months (p=0.04).Discussion/Conclusion: Remarkably few research studies have investigated pain prevalence among jazz musicians. This study displays, in accordance with previous studies on professional classical orchestra musicians [3,4], that the prevalence of musculoskeletal pain is high among jazz musicians. Significant association was seen between GJH and left hand pain. Although 86% of the jazz musicians employed at Swedish big bands participated in the study, the sample is still relatively small. More research on the health situation among jazz musicians is warranted, including freelance musicians who constitute a large group of the professional jazz musicians.References 1: Hakim, A. J., and R. Grahame. A simple questionnaire to detect hypermobility: an adjunct to the assessment of patients with diffuse musculoskeletal pain. International journal of clinical practice.2003; 57(3): 163-166.2: Kuorinka, Ilkka, et al. Standardised Nordic questionnaires for the analysis of musculoskeletal symptoms. Applied ergonomics. 1987; 18(3): 233-7.3: Paarup HM, Baelum J, Holm JW, Manniche C, Wedderkopp N. Prevalence and consequences of musculoskeletal symptoms in symphony orchestra musicians vary by gender: a cross-sectional study. Bmc Musculoskeletal Disorders. 2011; 12: 223-234.4: Leaver R, Harris EC, Palmer KT. Musculoskeletal pain in elite professional musicians from British symphony orchestras. Occup Med (Lond). 2011;61:549-55.

  • 48.
    Thorgren, Sara
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Caiman, Elin
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    The Role of Psychological Safety in Implementing Agile Methods across Cultures2019In: Research technology management, ISSN 0895-6308, E-ISSN 1930-0166, Vol. 62, no 2, p. 31-39Article in journal (Refereed)
    Abstract [en]

    Overview: This paper emphasizes the cultural challenges of implementing Agile methods. We applied a psychological safety framework in an empirical case where Agile methods were implemented across workplace cultures, which helped define challenges related to psychological safety in three areas: (1) cultural differences related to attitudes toward inclusiveness, (2) cultural differences related to perceptions of and trust in collective responsibility, and (3) cultural differences related to openness in communication. These findings suggest that working across cultural boundaries adds to the challenges with Agile implementation found in other studies. 

  • 49.
    Tretten, Phillip
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Aronsson, Ida
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    The development of an aircraft maintenance technician headset2016Conference paper (Refereed)
    Abstract [en]

    Aircraft maintenance technicians work in a situation where the implementation and use of new technology is uncommon. This is so to reduce the risk for errors considered to be a result of design errors, of the system or tools used. Earlier studies have shown that more advanced equipment, such as, tablets, Personal Digital Assistants, etc. can be used to help reduce the number of manuals, amounts of paperwork, track actions better, and reduce the number of steps in the work process. To take this process a step further was the ISO 9241:210 standard followed, 10 technicians were interviewed, 6 separate observations were conducted, and the technicians were consulted in development of a design requirements for a headset to see in what way a aircraft maintenance technician daily maintenance operations can be improved. The resulted requirements were, a headset should be placed around the head over the forehead for a steady fit during the varied working positions of the aircraft technicians, it is to be made of lightweight and smooth fabric, which features elasticity and comfort for the skin, adaptability for different headsizes, the construction is made all in one piece to be simple yet robust to handle, the headset is to be placed/fit firmly onto the head during a working day, providing ability to access data and information effortlessly through the device which operates with augmented reality technology, an interactive way of handling data and information, information is to be visualized, and the information needed in the daily work is to be gathered and easily accessed in one place, which includes the channels for communication.

  • 50.
    Varga, Pal
    et al.
    Budapest University of Technology and Economics.
    Blomstedt, Fredrik
    BNearIT Inc., Lulea.
    Ferreira, Luis Lino
    ISEP, Polytechnic of Porto – School of Engineering.
    Eliasson, Jens
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Johansson, Mats
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Martínez de Soria, Iker
    Tecnalia Research and Innovation, Bilbao.
    Making system of systems interoperable: The core components of the arrowhead framework2017In: Journal of Network and Computer Applications, ISSN 1084-8045, E-ISSN 1095-8592, Vol. 81, p. 85-95Article in journal (Refereed)
    Abstract [en]

    The objective of the Arrowhead Framework is to efficiently support the development, deployment and operation of interconnected, cooperative systems. It is based on the Service Oriented Architecture philosophy. The building elements of the framework are systems that provide and consume services, and cooperate as systems of systems. Some commonly used systems, such as orchestration, authorization or service registry are considered as core. These can be used by any system of systems that follow the guidelines of the Arrowhead Framework.

    Within the framework, systems – using different information exchange technologies during collaboration – are helped through various approaches. These include the so-called Interoperability Layer, as well as systems and services for translation. Furthermore, one of the main problems of developing such highly interoperable systems is the lack of understanding between various development groups. Adequate development and service documentation methodologies can help to overcome this issue.

    The design, development and verification methodology for each service, system and system of systems within the Arrowhead Framework supports that these can be implemented, verified, deployed, and run in an interoperable way. This paper presents an overview of the framework together with its core elements – and provides guidelines for the design and deployment of interoperable, Arrowhead-compliant cooperative systems.

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