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  • 1.
    Mishra, Madhav
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    van Riet, Maarten
    Alliander N.V., The Netherlands.
    A channel model for power line communication using 4PSK technology for diagnosis: Some lessons learned2018In: International Journal of Electrical Power & Energy Systems, ISSN 0142-0615, E-ISSN 1879-3517, Vol. 95, 617-634 p.Article in journal (Refereed)
    Abstract [en]

    Modern smart grids and smart metering concepts are based on reliable digital communications. The absence of dedicated communications media, such as telephone lines or fibre optics within a power line network, can make transmission challenging. Electrical power companies are interested in implementing an overall communicating power line network. The power line communication (PLC) system uses the electric power distribution grid as a data transmission medium. The data transmission problem resulted due to poorly developed Medium Voltage Network of PLC Channel Model and challenges in data transmission technology, so this hampers better performance. This paper studies PLC over a medium voltage network with a goal of achieving greater bit rates and communication that is more reliable over power lines. It presents a complete channel model of a PLC system and evaluation of Bit Error Rate (BER) of Phase Shift Keying (PSK) when corrupted with noise. It calculates the number of sections between two substations to determine signal loss. The PSK modulation scheme in simulation is experimentally found to be more robust against such power line distortions as noise for point-to-point transmission. The model and calculations use Matlab and QUCS.

  • 2.
    Jouybari, Nima
    et al.
    Department of Mechanical Engineering, Tarbiat Modares University.
    Maerefat, Mehdi
    Department of Mechanical Engineering, Tarbiat Modares University.
    Lundström, T. Staffan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Eshagh Nimvari, Majid
    Faculty of Engineering Technologies, Amol University of Special Modern Technologies, Amol.
    Gholami, Zahra
    Department of Food and Agriculture, Standard Research Institute, Karaj.
    A General Macroscopic Model for Turbulent Flow in Porous Media2018In: Journal of Fluids Engineering - Trancactions of The ASME, ISSN 0098-2202, E-ISSN 1528-901X, Vol. 140, no 1, 011201Article in journal (Refereed)
    Abstract [en]

    The present study deals with the generalization of a macroscopic turbulence model in porous media using a capillary model. The additional source terms associated with the production and dissipation of turbulent kinetic energy due to the presence of solid matrix are calculated using the capillary model. The present model does not require any prior pore scale simulation of turbulent flow in a specific porous geometry in order to close the macroscopic turbulence equations. Validation of the results in packed beds, periodic arrangement of square cylinders, synthetic foams and longitudinal flows such as pipes, channels and rod bundles against available data in the literature reveals the ability of the present model in predicting turbulent flow characteristics in different types of porous media. Transition to the fully turbulent regime in porous media and different approaches to treat this phenomenon are also discussed in the present study. Finally, the general model is modified so that it can be applied to lower Reynolds numbers below the range of fully turbulent regime in porous media.

  • 3.
    Liu, Yanan
    et al.
    School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou, .
    Cai, Xiaoping
    School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou .
    Sun, Zhi
    School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou .
    Jiao, Xinyang
    School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou.
    Akhtar, Farid
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Wang, Jianzhong
    State Key Laboratory of Porous Metal Materials, Northwest Institute for Non-ferrous Metal Research, Xi'an .
    Feng, Peizhong
    School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou.
    A novel fabrication strategy for highly porous FeAl/Al2O3 composite by thermal explosion in vacuum2018In: Vacuum, ISSN 0042-207X, Vol. 149, 225-230 p.Article in journal (Refereed)
    Abstract [en]

    The high porosity of FeAl/Al2O3 composites was successfully prepared via a low-energy consumption method of thermal explosion (TE) in vacuum from reactant mixtures of Fe, Al and Fe2O3. The temperature profiles, phase compositions, microstructure, porosity and pore size of the products were investigated. The TE reactions were ignited between 639 and 648 °C and maximum combustion temperatures reached to 1196–1867 °C. XRD patterns showed that FeAl, Fe2Al5 and Al2O3 were formed via TE reaction, and FeAl and Al2O3 were evolved as dominant phase after the final sintering at 1100 °C. The FeAl/Al2O3 composites exhibited an interconnected pore structure with porosities and pore size of 52–61% and 27–32 μm, respectively.

  • 4.
    Atashipour, Seyed Rasoul
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering. Department of Architecture and Civil Engineering, Division of Structural Engineering, Chalmers University of Technology.
    Girhammar, Ulf Arne
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Challamel, Noël
    Université de Bretagne Sud, UBS – Institut Dupuy de Lôme, Centre de Recherche.
    A weak shear web model for deflection analysis of deep composite box-type beams2018In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 155, 36-49 p.Article in journal (Refereed)
    Abstract [en]

    Deep box-type beams, consisting of framing members and sheathings, are sensitive to shear deformations and hence appropriate refined theories or complicated magnification factors are needed to be used to obtain accurate results. For sheathings or webs between the framing members that are weak in shear, additional shear deformations occur corresponding to the relative axial displacement between the framing members. These sandwich-type or partial interaction-type of in-plane shear behaviour between the framing members, needs to be taken into account, especially when the web shear stiffness is very low. The composite box-type beam treated here is composed of three framing members with sheathings on both sides. To incorporate effects of the sheathings shear deformations between the framing members on the deflection, the sheathings, here called web interlayers, are modelled as shear media with equivalent slip moduli corresponding to a partially interacting composite beam model. Governing equilibrium equations of the model are obtained using the minimum total potential energy principle and solved explicitly. The obtained results are compared with those based on different conventional beam theories and 3-D finite element (FE) simulations. It is shown that the model is capable of predicting accurately the deflection for a wide range of geometry and property parameters. It is demonstrated that the deflection of such deep box-type beams can be expressed as the summation of three different effects, namely bending deformations, conventional shear deformations in the framing members and sheathings, and additional in-plane shear deformations or shear slips of the weak web causing relative axial displacements between the framing members.

  • 5.
    Zhang, Liangwei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Lin, Janet
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Karim, Ramin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Adaptive Kernel Density-based Anomaly Detection for Nonlinear Systems2018In: Knowledge-Based Systems, ISSN 0950-7051, E-ISSN 1872-7409, Vol. 139, no 1, 50-63 p.Article in journal (Refereed)
    Abstract [en]

    This paper presents an unsupervised, density-based approach to anomaly detection. The purpose is to define a smooth yet effective measure of outlierness that can be used to detect anomalies in nonlinear systems. The approach assigns each sample a local outlier score indicating how much one sample deviates from others in its locality. Specifically, the local outlier score is defined as a relative measure of local density between a sample and a set of its neighboring samples. To achieve smoothness in the measure, we adopt the Gaussian kernel function. Further, to enhance its discriminating power, we use adaptive kernel width: in high-density regions, we apply wide kernel widths to smooth out the discrepancy between normal samples; in low-density regions, we use narrow kernel widths to intensify the abnormality of potentially anomalous samples. The approach is extended to an online mode with the purpose of detecting anomalies in stationary data streams. To validate the proposed approach, we compare it with several alternatives using synthetic datasets; the approach is found superior in terms of smoothness, effectiveness and robustness. A further experiment on a real-world dataset demonstrated the applicability of the proposed approach in fault detection tasks.

  • 6.
    Leijonhufvud, Susanna
    Luleå University of Technology, Department of Arts, Communication and Education, Music and dance.
    Affordances of Music Streaming based on Exploratory Media Archaeology: A presentation of the completed PhD-project Liquid Streaming focusing the affordance of musicking for the public via the Spotify streaming service with an emphasis on method2018Conference paper (Refereed)
    Abstract [en]

    In my dissertation, I have accounted for the affordances of musicking brought about by streamed music with the case example of Spotify. In order to perform a study orbiting the realm of music streaming, mainly digital sources have been used; Internet sources and software program of the streaming service. In the presentation, I will focus on issues concerning those two major roots. Within the latter I will present, problematize and conclude how; the Internet can be used as a field of sources, and on what terms the Internet can be regarded as an Archive. Also, what alternatives researchers can depend on when practising research within the realm of the Internet. The sources have, over time, been shown to change content, update, disappear, change resolution or package, which means that digital sources such as source material as well as methodology operating in such a field need to be problematized. First of all, I will account for how a phenomenon such as the Spotify streaming service is a multidimensional feature where appearance and featured functions depend on a number of things such as geographical market zone, subscription zone, the digital device used for access, and previous user-generated history. Researching a platform based software program like this brings particular issues for the researcher. I will present how these issues have been recognised and managed in my research. Secondly, I will address Internet as a base for research. The Internet provides a plethora of available sources, and as such Internet brings the affordance of accessing a tremendous amount of data opening up for possibilities that were not available prior to digitalisation. For instance, interviews and talks by interesting people might be available on-line whereas the same persons may be difficult or impossible to reach in ordinary life. Contemporary culture on the Internet, characterised by free culture and shared content further supply massive amount of data to be researched. Further, many services on the Internet provide access to local archives where content can be searched for, and a great number of sources can be screened regarding particular content. The popular phrase: “Once on the Internet, always on the Internet” has been found to be a truth with modification. I will present four different examples of issues concerning using the Internet as an archive and how such issues can be tackled within research concerning questions of reliability and trustworthiness. The first (i) example is how content many times are personalised, why an "objective" or public view can be impossible to gain. Further, it can be impossible to gain access to how personalisation is conducted. The second (ii) example is how sources, such as music, can be limited to certain geographical restrictions and thus only accessed from certain IP-addresses for the researcher. The third (iii) example is how sources may be removed and deleted. This is the case with some personal information as individuals have a right to be forgotten. Another example is how documents from the government offices are removed when there is a new government in office. The fourth (iv) example addresses the issue where a source might remain on the Internet but presented in a different digital format than the original content.

  • 7.
    Ljunggren, Fredrik
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Simmons, Christian
    Simmons akustik och utveckling, Chalmers Teknikpark, Gothenburg, Sweden.
    Airborne sound insulation between dwellings, from 50 vs. 100 Hz: a compilation of Swedish field surveys2018In: Applied Acoustics, ISSN 0003-682x, Vol. 133, 58-63 p.Article in journal (Refereed)
    Abstract [en]

    It has for long been debated whether 50 or 100 Hz is the proper lower frequency limit when evaluating airborne sound insulation between dwellings. Although 100 Hz is the lowest third-octave band within most regulations, there is an ongoing interest in paying more attention to lower frequencies. In Sweden, evaluation from 50 Hz became mandatory already in 1999 wherefore unique experiences are available by now. In this paper, extensive data in terms of field measurements and questionnaire surveys from in total 46 building objects of various constructions have been compiled. A number of single number quantities, standardized by ISO as well as alternatives, are compared concerning their correlation against the subjectively rated annoyance responded by the residents. The statistical evidence for a 50 Hz limit was found to be small considering the total database but when the lightweight buildings were analyzed by their own, the importance of frequencies below 100 Hz became clearer. The overall recommendation is to include frequencies from 50 Hz in order to achieve good sound protection against a broad variety of sound sources, including music and other possible items generating low frequencies.

  • 8.
    Singh, Anshu A.
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Geng, Shiyu
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Herrera Vargas, Natalia
    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.
    Aligned plasticized polylactic acid cellulose nanocomposite tapes: Effect of drawing conditions2018In: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 104, 101-107 p.Article in journal (Refereed)
    Abstract [en]

    Aligned nanocomposite tapes based on plasticized polylactic acid (PLA) and 1 wt.% cellulose nanofibers (CNF) were prepared using uniaxial solid-state drawing, and the effects of drawing conditions including temperature, speed and draw ratio on the material were studied. Microscopy studies confirmed alignment and the formation of ‘shish-kebab’ morphology in the drawn tape. Mechanical properties demonstrate that the solid-state drawing is a very effective way to produce stronger and tougher PLA nanocomposites, and the toughness can be improved 60 times compared to the undrawn tape. Additionally, the thermal properties, i.e. storage modulus, glass transition temperature and degree of crystallinity were improved. These improvements are expected due to the synergistic effect of CNF in the nanocomposite and orientations induced by the solid-state drawing.

  • 9.
    Shadram, Farshid
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction.
    Mukkavaara, Jani
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction.
    An Integrated BIM-based framework for the optimization of the trade-off between embodied and operational energy2018In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 158, 1189-1205 p.Article in journal (Refereed)
    Abstract [en]

    Design choices with a unilateral focus on the reduction of operational energy for developing energy-efficient and near-zero energy building practices can increase the impact of the embodied energy, as there is a trade-off between embodied and operational energy. Multi-objective optimization approaches enable exploration of the trade-off problems to find sustainable design strategies, but there has been limited research in applying it to find optimal design solution(s) considering the embodied versus operational energy trade-off. Additionally, integration of this approach into a Building Information Modeling (BIM) for facilitating set up of the building model toward optimization and utilizing the benefits of BIM for sharing information in an interoperable and reusable manner, has been mostly overlooked. To address these issues, this paper presents a framework that supports the making of appropriate design decisions by solving the trade-off problem between embodied and operational energy through the integration of a multi-objective optimization approach with a BIM-driven design process. The applicability of the framework was tested by developing a prototype and using it in a case study of a low energy dwelling in Sweden, which showed the potential for reducing the building’s Life Cycle Energy (LCE) use by accounting for the embodied versus operational energy trade-off to find optimal design solution(s). In general, the results of the case study demonstrated that in a low energy dwelling, depending on the site location, small reductions in operational energy (i.e. 140 GJ) could result in larger increases in embodied energy (i.e. 340 GJ) and the optimization process could yield up to 108 GJ of LCE savings relative to the initial design. This energy saving was equivalent to up to 8 years of the initial design’s operational energy use for the dwelling, excluding household electricity use.

  • 10.
    Thaduri, Adithya
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Verma, Ajit Kumar
    Western Norway University of Applied Sciences, Haugesund .
    Kumar, Uday
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Analytics for Maintenance of Transportation in Smart Cities2018In: Quality, IT and Business Operations: Modeling and Optimization / [ed] Kapur P., Kumar U., Verma A., Singapore: Springer, 2018, 81-91 p.Chapter in book (Refereed)
    Abstract [en]

    Cities typically face a wide range of management and maintenance problems. They are complex environments in which digital technologies are more and more pervasive; this digitization of urban environment provided a scope for enriched environment that has capability for data-driven methods. The connections and exchange of data increase and the need for data acquisition, processing, and management become an extremely important added value to the community. The inclusion of digitization and incorporation of predictive analytics provide a base for a sustainable smart city. This work considers an overview of different challenges that utilizes different technologies within a smart city maintenance with respect to transportation. A conceptual framework is proposed to handle the generated data for decision for control, monitoring, fault diagnosis, and maintenance of more and more complex systems.

  • 11.
    Rodushkin, Ilia
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Laboratory Group, ALS Scandinavia AB, Luleå..
    Paulukat, Cora
    ALS Laboratory Group, ALS Scandinavia AB, Luleå..
    Pontér, Simon
    ALS Laboratory Group, ALS Scandinavia AB, Luleå..
    Engström, Emma
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Laboratory Group, ALS Scandinavia AB, Luleå..
    Baxter, Douglas
    ALS Laboratory Group, ALS Scandinavia AB, Luleå..
    Sörlin, Dieke
    ALS Laboratory Group, ALS Scandinavia AB, Luleå..
    Pallavicini, Nicola
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Laboratory Group, ALS Scandinavia AB, Luleå..
    Rodushkina, Katerina
    Department of Chemistry, Uppsala University, Uppsala..
    Application of double-focusing sector field ICP-MS for determination of ultratrace constituents in samples characterized by complex composition of the matrix2018In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 622-623, 203-213 p.Article in journal (Refereed)
    Abstract [en]

    The performance of double focusing, sector field mass spectrometry (ICP-SFMS) for determination of analytes, including technology critical elements (TCE), at ultra-trace levels in environmental and clinical matrices was critically evaluated. Different configurations of the ICP-SFMS introduction system as well as various sample preparations, pre-concentration and matrix separation methods were employed and compared. Factors affecting detection capabilities and accuracy of data produced (instrumental sensitivity, contamination risks, purity of reagents, spectral interferences, matrix effects, analyte recovery and losses) were discussed. Optimized matrix-specific methods were applied to a range of reference and control materials (riverine, brackish and seawaters; whole blood, serum and urine) as well as tap water and snow samples collected in the area of Luleå city, northern Sweden; brackish and seawater from the Laptev Sea; venous blood samples with a special emphasis on determination of Au, Ag, Ir, Os, Pd, Pt, Re, Rh, Ru, Sb and Te. Even though these low abundant elements are relatively under-documented, the results produced were compared with published data, where available.

  • 12.
    Hakima, Houman
    et al.
    University of Toronto Institute for Aerospace Studies, 4925 Dufferin Street, Toronto.
    Emami, Reza
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology. Institute for Aerospace Studies, University of Toronto.
    Assessment of active methods for removal of LEO debris2018In: Acta Astronautica, ISSN 0094-5765, E-ISSN 1879-2030, Vol. 144, 225-243 p.Article in journal (Refereed)
    Abstract [en]

    This paper investigates the applicability of five active methods for removal of large low Earth orbit debris. The removal methods, namely net, laser, electrodynamic tether, ion beam shepherd, and robotic arm, are selected based on a set of high-level space mission constraints. Mission level criteria are then utilized to assess the performance of each redirection method in light of the results obtained from a Monte Carlo simulation. The simulation provides an insight into the removal time, performance robustness, and propellant mass criteria for the targeted debris range. The remaining attributes are quantified based on the models provided in the literature, which take into account several important parameters pertaining to each removal method. The means of assigning attributes to each assessment criterion is discussed in detail. A systematic comparison is performed using two different assessment schemes: Analytical Hierarchy Process and utility-based approach. A third assessment technique, namely the potential-loss analysis, is utilized to highlight the effect of risks in each removal methods

  • 13.
    McCarthy, David T.
    et al.
    Environmental and Public Health Microbiology Laboratory (EPHM Lab), Department of Civil Engineering, Monash University.
    Zhang, Kefeng
    Monash Infrastructure Research Institute, Department of Civil Engineering, Monash University.
    Westerlund, Camilla
    Water Coordinator, Water Authority-bottenvikens Water District Lulea.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Bertrand-Krajewski, Jean-Luc
    Univ Lyon, INSA Lyon.
    Fletcher, Tim D.
    School of Ecosystem and Forest Sciences, Faculty of Science, The University of Melbourne.
    Deletic, Ana
    Monash Infrastructure Research Institute, Department of Civil Engineering, Monash University.
    Assessment of sampling strategies for estimation of site mean concentrations of stormwater pollutants2018In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 129, 297-304 p.Article in journal (Refereed)
    Abstract [en]

    The estimation of stormwater pollutant concentrations is a primary requirement of integrated urban water management. In order to determine effective sampling strategies for estimating pollutant concentrations, data from extensive field measurements at seven different catchments was used. At all sites, 1-min resolution continuous flow measurements, as well as flow-weighted samples, were taken and analysed for total suspend solids (TSS), total nitrogen (TN) and Escherichia coli (E. coli). For each of these parameters, the data was used to calculate the Event Mean Concentrations (EMCs) for each event. The measured Site Mean Concentrations (SMCs) were taken as the volume-weighted average of these EMCs for each parameter, at each site. 17 different sampling strategies, including random and fixed strategies were tested to estimate SMCs, which were compared with the measured SMCs. The ratios of estimated/measured SMCs were further analysed to determine the most effective sampling strategies. Results indicate that the random sampling strategies were the most promising method in reproducing SMCs for TSS and TN, while some fixed sampling strategies were better for estimating the SMC of E. coli. The differences in taking one, two or three random samples were small (up to 20% for TSS, and 10% for TN and E. coli), indicating that there is little benefit in investing in collection of more than one sample per event if attempting to estimate the SMC through monitoring of multiple events. It was estimated that an average of 27 events across the studied catchments are needed for characterising SMCs of TSS with a 90% confidence interval (CI) width of 1.0, followed by E.coli (average 12 events) and TN (average 11 events). The coefficient of variation of pollutant concentrations was linearly and significantly correlated to the 90% confidence interval ratio of the estimated/measured SMCs (R2 = 0.49; P < 0.01) as well as the number of events required to achieve certain accuracy, and hence could be a promising surrogate for determining the sampling frequency needed to accurately estimate SMCs of pollutants

  • 14.
    Grane, Camilla
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Assessment selection in human-automation interaction studies: The Failure-GAM2E and review of assessment methods for highly automated driving2018In: Applied Ergonomics, ISSN 0003-6870, E-ISSN 1872-9126, Vol. 66, 182-192 p.Article in journal (Refereed)
    Abstract [en]

    Highly automated driving will change driver's behavioural patterns. Traditional methods used for assessing manual driving will only be applicable for the parts of human-automation interaction where the driver intervenes such as in hand-over and take-over situations. Therefore, driver behaviour assessment will need to adapt to the new driving scenarios. This paper aims at simplifying the process of selecting appropriate assessment methods. Thirty-five papers were reviewed to examine potential and relevant methods. The review showed that many studies still relies on traditional driving assessment methods. A new method, the Failure-GAM2E model, with purpose to aid assessment selection when planning a study, is proposed and exemplified in the paper. Failure-GAM2E includes a systematic step-by-step procedure defining the situation, failures (Failure), goals (G), actions (A), subjective methods (M), objective methods (M) and equipment (E). The use of Failure-GAM2E in a study example resulted in a well-reasoned assessment plan, a new way of measuring trust through feet movements and a proposed Optimal Risk Management Model. Failure-GAM2E and the Optimal Risk Management Model are believed to support the planning process for research studies in the field of human-automation interaction.

  • 15.
    Wagner, L.
    et al.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany; Technische Universität Dresden, Dresden, Germany.
    Akhmadaliev, S.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.
    Anders, M.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.
    Bemmerer, D.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany; National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, United States.
    Caciolli, A.
    Dipartimento di Fisica e Astronomia, Università degli Studi di Padova, Padova, Italy; Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Padova, Padova, Italy.
    Gohl, S.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.
    Grieger, M.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.
    Junghans, A.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.
    Marta, M.
    GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany.
    Munnik, F.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.
    Reinhardt, T.P.
    Technische Universität Dresden, Dresden, Germany.
    Reinicke, S.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany; Technische Universität Dresden, Dresden, Germany.
    Röder, M.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany; Technische Universität Dresden, Dresden, Germany.
    Schmidt, K.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany; Technische Universität Dresden, Dresden, Germany.
    Schwengner, R.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany; Technische Universität Dresden, Dresden, Germany.
    Serfling, M.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany; Technische Universität Dresden, Dresden, Germany.
    Takács, M.P.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany; Technische Universität Dresden, Dresden, Germany.
    Szücs, T.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Wagner, A.
    Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.
    Zuber, K.
    Technische Universität Dresden, Dresden, Germany.
    Astrophysical S factor of the N 14 (p,γ) O 15 reaction at 0.4-1.3 MeV2018In: Physical Review C: Covering Nuclear Physics, ISSN 2469-9985, E-ISSN 2469-9993, Vol. 97, no 1, 015801Article in journal (Refereed)
    Abstract [en]

    The N14(p,γ)O15 reaction is the slowest reaction of the carbon-nitrogen cycle of hydrogen burning and thus determines its rate. The precise knowledge of its rate is required to correctly model hydrogen burning in asymptotic giant branch stars. In addition, it is a necessary ingredient for a possible solution of the solar abundance problem by using the solar N13 and O15 neutrino fluxes as probes of the carbon and nitrogen abundances in the solar core. After the downward revision of its cross section due to a much lower contribution by one particular transition, capture to the ground state in O15, the evaluated total uncertainty is still 8%, in part due to an unsatisfactory knowledge of the excitation function over a wide energy range. The present work reports precise S factor data at twelve energies between 0.357 and 1.292 MeV for the strongest transition, capture to the 6.79-MeV excited state in O15, and at ten energies between 0.479 and 1.202 MeV for the second strongest transition, capture to the ground state in O15. An R-matrix fit is performed to estimate the impact of the new data on astrophysical energies. The recently suggested slight enhancement of the 6.79-MeV transition at low energy could not be confirmed. The present extrapolated zero-energy S factors are S6.79(0)=1.24±0.11 keV b and SGS(0)=0.19±0.05 keV b.

  • 16.
    Bengtsson, Peter
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human and technology.
    Attuning the ‘pedestrian-vehicle’ and ‘driver-vehicle’: Why attributing a mind to a vehicle matters2018In: Advances in Intelligent Systems and Computing, ISSN 2194-5357, E-ISSN 2194-5365, Vol. 722, 19-22 p.Article in journal (Refereed)
    Abstract [en]

    Vehicle automated driving systems, capable of performing all dynamic driving tasks are profoundly changing the traffic environment. With increased automation the vehicles are gradually becoming artificial agents that act and interact in conjunction with human agents, creating a pristine social context. This paper addresses the interaction between ‘pedestrian-vehicle’ and ‘driver-vehicle’. The idea is to make interaction as humanlike as possible, to increase safety and a positive user experience. We suggest that concepts describing social attunement in human-human interaction also can be applied to human-vehicle interaction. Social attunement implies a scenario where human and vehicle share intentions, infer goals of the interaction partner, are mutually predictable, and understand performance limitations. Furthermore, we propose the use of an in-vehicle avatar interface to assist in this interaction. A reason for using an avatar is that it can be hypothesised that the user can interact more naturally with an anthropomorphic artificial agent. 

  • 17.
    Mishra, Madhav
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Martinsson, Jesper
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mathematical Science.
    Rantatalo, Matti
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Goebel, Kai
    NASA Ames Research Center, Intelligent Systems Division, Moffett Field, CA.
    Bayesian hierarchical model-based prognostics for lithium-ion batteries2018In: Reliability Engineering & System Safety, ISSN 0951-8320, E-ISSN 1879-0836, Vol. 172, 25-35 p.Article in journal (Refereed)
    Abstract [en]

    To optimise operation and maintenance, knowledge of the ability to perform the required functions is vital. The ability is governed by the usage of the system (operational issues) and availability aspects like reliability of different components. This paper proposes a Bayesian hierarchical model (BHM)-based prognostics approach applied to Li-ion batteries, where the goal is to analyse and predict the discharge behaviour of such batteries with variable load profiles and variable amounts of available discharge data. The BHM approach enables inferences for both individual batteries and groups of batteries. Estimates of the hierarchical model parameters and the individual battery parameters are presented, and dependencies on load cycles are inferred. A BHM approach where the operational and reliability aspects end of life (EoD) and end of life (EoL) is studied where its shown that predictions of EoD can be made accurately with a variable amount of battery data. Without access to measurements, e.g. predicting a new battery, the predictions are based only on the prior distributions describing the similarity within the group of batteries and their dependency on the load cycle. A discharge cycle dependency can also be identified in the result giving the opportunity to predict the battery reliability.

  • 18.
    Knutsson, Roger
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Viklander, Peter
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Knutsson, Sven
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Benefits of Advanced Constitutive Modeling when Estimating Deformations in a Tailings Dam2018In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 8, no 1, 1-19 p.Article in journal (Refereed)
  • 19.
    Salehpour, Shoboo
    et al.
    Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Tehran, Karaj.
    Jonoobi, Mehdi
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University of Tehran, Karaj.
    Ahmadzadeh, Masoud
    Department of Plant Protection, Faculty of Agriculture and Natural Resources, University of Tehran, Karaj.
    Siracusa, Valentina
    Department of Chemical Science, University of Catania.
    Rafieian, Fatemeh
    Food Science Department, Agriculture College, Isfahan University of Technology.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Biodegradation and ecotoxicological impact of celluose nanocomposites in municipal solid waste composting2018In: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 111, 264-270 p.Article in journal (Refereed)
    Abstract [en]

    Biodegradable nanocomposites were prepared from polyvinyl alcohol (PVA) and cellulose nanofiber (CNF) by using liquid nitrogen, freeze drying and hot press techniques. The effect of CNF content on the biodegradability of the films was investigated by visual observation, scanning electron microscopy (SEM), weight loss, CO2 evolution, differential scanning calorimetry, measuring the amount of mineralized carbon of the specimens buried in municipal solid waste. Ecotoxicity was evaluated by plants growth tests with cress and spinach. The results confirmed that the weight loss of nanocomposites was lower than that of neat PVA because of the zigzag pathways of microorganisms in the CNF presence. The SEM analysis showed extensive surface roughness and cracks for all samples, indicating the initiation of biodegradation. The CO2 evolution decreased with increasing CNF content from 0% to 10% and then, increased with further increase in the filler content (up to 30 wt%). The crystallinity of the PVA and its nanocomposites increased as a function of time because of the amorphous parts degradation. Preliminary results of the ecotoxicological test revealed that all the nanocomposites and neat PVA did not generate any negative effects on germination or development of the studied vegetal species.

  • 20.
    Vestin, Jenny
    et al.
    Swedish Geotechnical Institute (SGI), Sundsvall.
    Nordmark, Desiree
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Arm, Maria
    Swedish Geotechnical Institute (SGI), Linköping.
    Lind, Bo B.
    Swedish Geotechnical Institute (SGI), Göteborg.
    Lagerkvist, Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Biofuel ash in road stabilization: Lessons learned from six years of field testing2018In: Transportation Geotechnics, ISSN 2214-3912, Vol. 14, 146-156 p.Article in journal (Refereed)
    Abstract [en]

    In 2009, pulp mill fly ash was used for stabilizing the road base of a low-volume gravel road. Six years after stabilization, a two-year monitoring program and a complementary study were conducted to study the environmental and technical properties of the road and road material. Environmental properties were studied through chemical analysis of road samples by X-ray diffraction (XRF), inductively coupled plasma (ICP) technique and colorimetric techniques. The strength development was studied by falling weight deflectometer (FWD) and compressive strength tests. Potassium (K) and sulphate sulfur (SO4-S) concentrations in road material decreased by 40 and 55%, respectively during this time. Absolute concentrations of most trace elements increased. Leaching of chloride (Cl) salts from road samples decreased with time, while leaching of magnesium (Mg) and calcium (Ca) increased. Leaching of trace elements was below 0.5 mg/kg at all sampling occasions. The bearing capacity increased by 30-50%, and the infiltration capacity decreased compared to a reference section. The results showed that the ash-stabilized sections performed better than conventionally upgraded sections and achieved increased bearing capacity over time. Since the acid neutralizing capacity of the stabilized layer was high and lumps of unreacted ash were still left in the road, it was concluded that the ash material could be utilized once more in a potential end-of-life road recycling.

  • 21.
    Pauelsen, Mascha
    et al.
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Nyberg, Lars
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Röijezon, Ulrik
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Vikman, Irene
    Luleå University of Technology, Department of Health Sciences, Health and Rehab.
    Both psychological factors and physical performance are associated with fall-related concerns2018In: Aging Clinical and Experimental Research, ISSN 1594-0667, E-ISSN 1720-8319Article in journal (Refereed)
    Abstract [en]

    Background Fall-related concern strongly correlates to activity avoidance in older people.  In this complex phenomenon, different terminology and instruments are often used interchangeably. Three main concepts make up fall-related concerns: fear-of-falling, consequence concern, and falls self-efficacy. It is suggested that fall-related concerns are mediated by psychological and physical factors.

    Aims Our aims were to describe the prevalence of fall-related concerns and find explanatory factors for its most studied concept – falls self-efficacy – in an older population.

    Methods We executed a cross sectional study on a random sample of 153 community dwelling older people (70 years or older). We used validated and reliable instruments as well as structured interviews to gather data on the three concepts of fall-related concerns and possible mediating factors. We then calculated descriptive statistics on prevalence and regression models for the total group, and men and women separately.

    Results 70% of the total sample (80% of women and 53% of men) reported at least one of the three concepts of fall-related concern. For the total sample, fear-of-falling, morale and physical performance were associated factors with falls self-efficacy. For women, number of prescription medications was added. For men, physical performance and concerns for injury were associated.

    Conclusion Fall-related concern is prevalent in large proportions with higher prevalence for women than for men. Important factors are fear of falling, morale, and physical performance. Gender differences in the emergence and variance of fall-related concern and the relation between physical performance and fall-related concern should be targeted in future research endeavors. 

  • 22.
    Ögren, Yngve
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science. RISE ETC.
    Camera and laser-based diagnostic relevant for entrained flow reactors2018Licentiate thesis, comprehensive summary (Other academic)
  • 23.
    Nissilä, Tuukka
    et al.
    Fibre and Particle Engineering Research Unit, Faculty of Technology, University of Oulu.
    Karhula, Sakari S.
    Research Unit of Medical Imaging, Physics and Technology, University of Oulu.
    Saarakkala, Simo
    Research Unit of Medical Imaging, Physics and Technology, University of Oulu.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Fibre and Particle Engineering Research Unit, Faculty of Technology, University of Oulu.
    Cellulose nanofiber aerogels impregnated with bio-based epoxy using vacuum infusion: Structure, orientation and mechanical properties2018In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 155, 64-71 p.Article in journal (Refereed)
    Abstract [en]

    Cellulose nanofiber aerogels were used as preforms that were impregnated with a bio-epoxy resin via a widely used vacuum infusion process. The simple and straightforward nanocomposite processing approach resulted in an almost 70% improvement in the storage modulus of the polymer with only an 11.7 wt% cellulose nanofiber content. The nanofibers were well dispersed in the polymer matrix and the fiber structures were anisotropically aligned. The impregnation time of the aerogels was also significantly lower than that of the more commonly used nanopapers. It was thus shown that environmentally friendly and mechanically robust nanocomposites could be produced by impregnating cellulose nanofiber aerogels with a thermosetting resin using a processing approach that has potential to be scaled up for commercial use.

  • 24.
    Temiz, Serdar
    et al.
    Royal Institute of Technology (KTH), Stockholm.
    Brown, Terrence
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering. Royal Institute of Technology (KTH), Stockholm.
    Challenges in Data-Driven Innovation Toward European Digital Single Market: An Abstract2018In: Back to the Future: Using Marketing Basics to Provide Customer Value : Proceedings of the 2017 Academy of Marketing Science (AMS) Annual Conference / [ed] Nina Krey, Patricia Rossi, Cham: Springer, 2018, 245-246 p.Conference paper (Refereed)
    Abstract [en]

    In May 2015, the European Commission adopted a Digital Single Market Strategy (2015), which identifies Europe as a potential leader in the global digital economy. If EU fragmentation and barriers are removed, Digital Single Market (DSM) could contribute an additional €415 billion to European GDP. Further, the Digital Single Market could create opportunities for new start-ups, and business can develop and create value for the 500 million consumers.

    The European Digital Single Market (DSM) has three policy areas: (1) access to digital goods and services, (2) conditions for digital networks and innovative services, and (3) digital as a driver for growth (https://ec.europa.eu/digital-single-market/en/digital-single-market). In all these areas, data-driven services are an essential part of DSM.

    This research focuses on political, economic, social, technological, legal, and environmental (PESTEL) factors. Consider: To do this, a quantitative approach was used to analyze the data collected from four different data sources to understand major factors having impact on DSM:Digital Economy and Society Index (Desi), EU barometer, Digital Agenda key indicators, and public consultation. Based on our data analysis, we have found several data-based challenges in creating a digital single market as below:

    1. (a)

      Inequality within EU

       
    2. (b)

      Legislative gap with respect to digital content and data

       
    3. (c)

      Trust in a digital single market (in regard to data)

       
    4. (d)

      Privacy and security of digital software and systems

       

    Defining and understanding these challenges are vital to overcome obstacles hindering Digital Single Market goals.

  • 25.
    Trubetskaya, Anna
    et al.
    Thermochemical Energy Conversion Laboratory, Umeå University, Umeå.
    Brown, A.
    Chemical Engineering Department, Worcester Polytechnic Institute, Worcester, MA, United States.
    Tompsett, G.A.
    Chemical Engineering Department, Worcester Polytechnic Institute, Worcester, MA, United States.
    Timko, M.T.
    Chemical Engineering Department, Worcester Polytechnic Institute, Worcester, MA, United States.
    Kling, J.
    Center for Nanoscopy, Technical University of Denmark, Kgs. Lyngby, Denmark.
    Broström, M.
    Thermochemical Energy Conversion Laboratory, Umeå University, Umeå.
    Andersen, M.L.
    Department of Food Science, University of Copenhagen, Copenhagen, Denmark.
    Umeki, Kentaro
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Characterization and reactivity of soot from fast pyrolysis of lignocellulosic compounds and monolignols2018In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 212, 1489-1500 p.Article in journal (Refereed)
    Abstract [en]

    This study presents the effect of lignocellulosic compounds and monolignols on the yield, nanostructure and reactivity of soot generated at 1250 °C in a drop tube furnace. The structure of soot was characterized by electron microscopy techniques, Raman spectroscopy and electron spin resonance spectroscopy. The CO2 reactivity of soot was investigated by thermogravimetric analysis. Soot from cellulose was more reactive than soot produced from extractives, lignin and monolignols. Soot reactivity was correlated with the separation distances between adjacent graphene layers, as measured using transmission electron microscopy. Particle size, free radical concentration, differences in a degree of curvature and multi-core structures influenced the soot reactivity less than the interlayer separation distances. Soot yield was correlated with the lignin content of the feedstock. The selection of the extraction solvent had a strong influence on the soot reactivity. The Soxhlet extraction of softwood and wheat straw lignin soot using methanol decreased the soot reactivity, whereas acetone extraction had only a modest effect. 

  • 26.
    Linde, Stefan
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Climate policy support under political consensus: exploring the varying effect of partisanship and party cues2018In: Environmental Politics, ISSN 0964-4016, E-ISSN 1743-8934, Vol. 27, no 2, 228-246 p.Article in journal (Refereed)
    Abstract [en]

    By creating attitudinal rifts among partisan voters, political polarization is

    expected to negatively affect chances of effectively mitigating climate change.

    While such expectations generally have found support, less attention has been

    paid to the opposite claim that political consensus should eliminate the

    partisan dimension in climate change politics. This study tests this claim by

    studying how party identification, and party cues specifically, affects public

    policy attitudes in a context defined by political consensus. Using data from a

    large online access panel in Sweden, party identification and party cues are

    shown to matter for policy attitudes even in a consensus context. This effect is

    not limited to certain issues but is found across a wide range of policies, and

    the effect of party cues, for a given issue, varies across parties. The implications

    of this study and areas for future work are discussed.

  • 27.
    Calle Cordón, Álvaro
    et al.
    CEMOSA, Spain.
    Jiménez-Redondo, Noemi
    CEMOSA, Spain.
    Morales-Gámiz, J.
    CEMOSA, Spain.
    García-Villena, F. A.
    CEMOSA, Spain.
    Peralta-Escalante, J.
    CEMOSA, Spain.
    Garmabaki, Amir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Famurewa, Stephen Mayowa
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Duarte, Emanuel
    Infraestruturas de Portugal, Lisbon, Portugal.
    Morgado, João
    Infraestruturas de Portugal, Lisbon, Portugal.
    Combined RAMS and LCC analysis in railway and road transport infrastructures2018In: Proceedings of 7th Transport Research Arena TRA, Vienna, Austria, 2018Conference paper (Refereed)
  • 28.
    Westerberg, Lars-Göran
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Farré-Lladós, Josep
    ETSEIAT, Universitat Politècnica de Catalunya.
    Sarkar, Chiranjit
    Department of Mechanical Engineering, Indian Institute of Technology Patna, Bihta.
    Casals-Terré, Jasmina
    ETSEIAT, Universitat Politècnica de Catalunya.
    Contaminant particle motion in lubricating grease flow: a Computational Fluid Dynamics approach2018In: Lubricants, ISSN 2075-4442Article in journal (Refereed)
    Abstract [en]

    In this paper numerical simulations of particle migration in lubricating grease flow is  presented. The rheology of three lithium greases with NLGI grade 00, 1, and 2 respectively are  considered. The grease is modeled as a single-phase Herschel-Bulkley fluid, and the particle  migration has been considered in two different grease pockets formed between two concentric  cylinders where the inner cylinder is rotating and driving the flow. In the wide grease pocket the  width of the gap is much smaller compared to the axial length scale, enabling a one-dimensional  flow. In the narrow pocket the axial- and radial length is of the same order, yielding a  three-dimensional flow. It was found that the change in flow characteristics due to the influence of  the pocket lateral boundaries when going from the wide- to the narrow pocket, leads to a  significantly shorter migration time. Comparing the results with an existing migration model  treating the radial component contribution it was concluded that a solution to the flow in the whole  domain is needed together with a higher order numerical scheme to obtain a full solution to the  particle migration. This is more pronounced in the narrow pocket due to gradients in the flow  induced by the lateral boundaries.

  • 29.
    Chipp, Kerry
    et al.
    University of Pretoria.
    Strandberg, Carola
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Nath, Atanu
    Western Norway University of Applied Sciences, Sogndal.
    Abduljabbar, Meyser
    School of Industrial Engineering and Management, Royal Institute of Technology.
    Content Curatorship and Collaborative Filtering: A Symbolic Interactionist Approach2018In: Back to the Future: Using Marketing Basics to Provide Customer Value : Proceedings of the 2017 Academy of Marketing Science (AMS) Annual Conference / [ed] Nina Krey, Patricia Rossi, Cham: Springer, 2018, 705-715 p.Conference paper (Refereed)
    Abstract [en]

    This paper explores the premise whether sophisticated algorithms that drive curatorship of content for consumers consider a symbolic interactionist perspective on consumer desire for content and whether content offerings, personalisation and the consequent shaping of curatorship algorithms can be based on such an understanding. Curatorship of online content, whether this be product or information based, drives value, consumer engagement and profitability. Curatorship and recommender systems also deliver a personalised experience of the product or services. A review of the reasoning behind such systems reveals that most follow an empirical perspective, namely, the use of statistical tools and information systems algorithms on a behavioural dataset. A theoretically driven approach appears to be lacking. This paper seeks a theoretical approach to online content curatorship embedded in symbolic interactionism. In addition, it seeks to tease out the approach to one that embraces both notions of content curation based on similarity but also on a desire for difference and change. The paper looks at symbolic interactionism in the context of social and individual selves, its role in collaborative filtering, advances a set of propositions for a curation and collaborative filtering model and ends with the possible implications for marketing.

  • 30.
    Villanueva, Maria
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering. maria.villanueva@ltu.se.
    Chohan, Raeesah
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering. University of Cape Town.
    Conversion Theory in Marketing2018In: Back to the Future: Using Marketing Basics to Provide Customer Value : Proceedings of the 2017 Academy of Marketing Science (AMS) Annual Conference / [ed] Nina Krey, Patricia Rossi, Cham: Springer, 2018, 415-425 p.Conference paper (Refereed)
    Abstract [en]

    How do marketing campaigns encourage a majority group of consumers to support a minority group of consumers’ opinion? Why do consumers change their opinions? Why do consumers do what they do? Conversion theory addresses a simultaneous majority and minority influence on consumer behaviour. Whilst conversion theory is applied to various disciplines, there is a gap in literature on conversion theory as applied to the marketing discipline. This paper focuses on conversion theory in marketing and contributes by introducing three new propositions to marketing literature, namely, (1) marketing campaigns can convert the majority opinion to support the minority opinion privately and/or publicly when portraying ‘consistency’, (2) marketing campaigns can convert the majority opinion to support the minority opinion privately and/or publicly when portraying a style of thinking that encourages discussion amongst the majority, and (3) marketing campaigns can convert the majority opinion to support the minority opinion privately and/or publicly when the majority identifies themselves with the message of the marketing campaign.

  • 31.
    Paschen, Ulrich Michael
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Paschen, Jeannette
    Royal Institute of Technology (KTH), Stockholm.
    Keitzmann, Jan
    Beedie School of Business, Simon Fraser University.
    Cool Marketing for Icewine?: Producer’s Product Positioning, Segmentation, and Marketing Mix for Canadian Icewine: An Abstract2018In: Back to the Future: Using Marketing Basics to Provide Customer Value : Proceedings of the 2017 Academy of Marketing Science (AMS) Annual Conference / [ed] Nina Krey, Patricia Rossi, Cham: Springer, 2018, 337-338 p.Conference paper (Refereed)
    Abstract [en]

    Compared to the relative importance of icewine for the Canadian wine industry and the uniqueness of the product in the luxury wine and spirit segment, little attention has been paid to the marketing mix used by its producers. As a first step in addressing this gap, Paschen et al. (2016) developed a modified aesthetics and ontology framework to classify consumers of luxury wines and spirits with a focus on icewine. The framework separates the novice and the expert in the aesthetic dimension, while it distinguishes between transience and endurance in the ontology dimension. Working from these two dimensions, four distinct consumer groups have been identified: Carousers are novices on the aesthetics scale, while the ontological mode emphasizes the transient. Cabinet collectors are also novices, but the ontological mode emphasizes enduring. In contrast to the two preceding types, the connoisseur is an expert and a true consumer whose behavior emphasizes the transient. Finally, the cellar collector is an expert where the ontological mode emphasizes enduring. The current paper examines where icewine producers place consumers within this typology. Using semi-structured interviews led with representatives of five icewine producers, the authors gathered information on production, product range, positioning, and consumers. The interviews uncovered remarkably homogenous approaches to positioning and marketing icewine. Most purchasers were regarded as novices. With duty free as the predominant sales channel and on-site winery experiences a secondary channel, only limited efforts to address or create experts were discovered. The ontological dimension of the typology was defined by icewine’s changes through cellaring, making the predominant customer group the “carouser.” The marketing mix used was also similar between the different brands. Product variances uncovered were comparatively minor, with very similar price points and packaging approaches. This one-dimensional marketing approach bears risk for the category, which should be further explored and addressed through appropriate variations in the marketing mix

  • 32.
    Pahlberg, Tobias
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Thurley, Matthew
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Popovic, Djordje
    Jönköping University.
    Hagman, Olle
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Crack detection in oak flooring lamellae using ultrasound-excited thermography2018In: Infrared physics & technology, ISSN 1350-4495, E-ISSN 1879-0275, Vol. 88, 57-69 p.Article in journal (Refereed)
    Abstract [en]

    Today, a large number of people are manually grading and detecting defects in wooden lamellae in the parquet flooring industry. This paper investigates the possibility of using the ensemble methods random forests and boosting to automatically detect cracks using ultrasound-excited thermography and a variety of predictor variables. When friction occurs in thin cracks, they become warm and thus visible to a thermographic camera. Several image processing techniques have been used to suppress the noise and enhance probable cracks in the images. The most successful predictor variables captured the upper part of the heat distribution, such as the maximum temperature, kurtosis and percentile values 92–100 of the edge pixels. The texture in the images was captured by Completed Local Binary Pattern histograms and cracks were also segmented by background suppression and thresholding.

    The classification accuracy was significantly improved from previous research through added image processing, introduction of more predictors, and by using automated machine learning. The best ensemble methods reach an average classification accuracy of 0.8, which is very close to the authors’ own manual attempt at separating the images (0.83).

  • 33.
    Elnekhaily, Sarah A.
    et al.
    Department of Materials Science and Engineering, Texas A&M University, College Station TX; Department of Metallurgical and Materials Eng., Faculty of Petroleum and Mining Eng., Suez University, Suez, Egypt.
    Talreja, Ramesh
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Materials Science and Engineering, Texas A&M University, College Station, TX; Department of Aerospace Engineering, Texas A&M University, College Station, TX .
    Damage initiation in unidirectional fiber composites with different degrees of nonuniform fiber distribution2018In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 155, 22-32 p.Article in journal (Refereed)
    Abstract [en]

    This paper reports a study of the initiation of the first failure event in unidirectional composites subjected to transverse tension. Two energy based point failure criteria – critical dilatational energy density and critical distortional energy density – are considered. The manufacturing induced disorder in the fiber distribution in the composite cross section is described in terms of the degree of nonuniformity, which is quantified and for which an algorithm is developed. The nonuniformity is captured in a representative volume element (RVE) whose minimum size is determined based on statistics of nearest fiber distance distribution. Several realizations of the RVE for three fiber volume fractions and three degrees of nonuniformity are analyzed using a finite element model. A parametric study of the effect of matrix/fiber stiffness ratio on the damage initiation is also conducted. Significant effects of the fiber distribution nonuniformity on the strain to onset of damage are found.

  • 34.
    Fernberg, Patrik
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Gong, Guan
    Swerea SICOMP AB, Piteå.
    Mannberg, Peter
    Swerea SICOMP AB, Piteå.
    Tsampas, Spyros
    Swerea SICOMP AB, Mölndal.
    Development of novel high Tg polyimide-based composites: Part I: RTM processing properties2018In: Journal of composite materials, ISSN 0021-9983, E-ISSN 1530-793X, Vol. 52, no 2, 253-260 p.Article in journal (Refereed)
    Abstract [en]

    In this study, an assessment of the composite processing-related properties of a newly developed 6-FDA-based phenylethynyl-terminated polyimide (available under the tradename NEXIMID®MHT-R) is presented. Processing schemes, used for preparing high quality carbon fibre-reinforced composites by the use of conventional resin transfer moulding are developed and presented. The influences of manufacturing parameters on glass transition temperature of the composites are presented. The results confirm that composites with exceptionally high Tg, in the range between 350 and 460℃ can be achieved. A manufacturing scheme that yields in composites with Tg of 370℃ is presented and proposed as a good candidate to serve as baseline for further studies.

  • 35.
    Tsampas, Spyros
    et al.
    Swerea SICOMP AB, Mölndal.
    Fernberg, Patrik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Joffe, Roberts
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Development of novel high Tg polyimide-based composites: Part II: Mechanical characterisation2018In: Journal of composite materials, ISSN 0021-9983, E-ISSN 1530-793X, Vol. 52, no 2, 261-274 p.Article in journal (Refereed)
    Abstract [en]

    In this study, the mechanical performance assessment of a newly developed carbon fibre-reinforced polyimide composite system T650/NEXIMID® MHT-R is presented. This system was subjected to a series of mechanical tests at ambient and elevated temperature (320℃) to determine basic material properties. Moreover, an additional test was conducted, using a T650/NEXIMID® MHT-R laminate in which the fibre sizing was thermally removed prior to laminate manufacturing, to investigate the effect of fibre treatment on mechanical performance. The experimental results indicated that the T650/NEXIMID® MHT-R composites along with exceptionally high Tg (360–420℃) exhibited competitive mechanical properties to other commercially available polyimide and epoxy-based systems. At elevated temperature, the fibre-dominated properties were not affected whilst the properties defined by matrix and fibre/matrix interface were degraded by approximately 20–30%. Finally, the fibre sizing removal did not affect the tensile and compressive strength, however, the shear strength obtained from short-beam shear test was deteriorated by approximately 15%. to serve as baseline for further studies.

  • 36.
    Rodríguez Ripoll, Mane
    et al.
    AC2T research GmbH, Wiener Neustadt.
    Totolin, Vladimir
    AC2T research GmbH, Wiener Neustadt.
    Gabler, Christoph
    AC2T research GmbH, Wiener Neustadt.
    Bernardi, Johannes
    USTEM, Technische Universität Wien.
    Minami, Ichiro
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Diallyl disulphide as natural organosulphur friction modifier via the in-situ tribo-chemical formation of tungsten disulphide2018In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 428, 659-668 p.Article in journal (Refereed)
    Abstract [en]

    The present work shows a novel method for generating in-situ low friction tribofilms containing tungsten disulphide in lubricated contacts using diallyl disulphide as sulphur precursor. The approach relies on the tribo-chemical interaction between the diallyl disulphide and a surface containing embedded sub-micrometer tungsten carbide particles. The results show that upon sliding contact between diallyl disulphide and the tungsten-containing surface, the coefficient of friction drops to values below 0.05 after an induction period. The reason for the reduction in friction is due to tribo-chemical reactions that leads to the in-situ formation of a complex tribofilm that contains iron and tungsten components. X-ray photoelectron spectroscopy analyses indicate the presence of tungsten disulphide at the contact interface, thus justifying the low coefficient of friction achieved during the sliding experiments. It was proven that the low friction tribofilms can only be formed by the coexistence of tungsten and sulphur species, thus highlighting the synergy between diallyl disulphide and the tungsten-containing surface. The concept of functionalizing surfaces to react with specific additives opens up a wide range of possibilities, which allows tuning on-site surfaces to target additive interactions.

  • 37.
    Bauer, Susanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Dissolved and suspended transport of tungsten, molybdenum, and vanadium in natural waters2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Some transition metals and metalloids occur primarily as oxyanions in natural waters including antimony, arsenic, chromium, molybdenum, tungsten and vanadium. These oxyanions can pass through cell walls along the same pathways as phosphate or sulfate. Some of these oxyanions are essential for life, but in high concentrations they become all toxic. Recent studies showed that tungsten probably is posing a risk to human health. The growing use of tungsten in industrial and military applications probably leads to an increased release of tungsten to the environment. It has also been shown that the use of studded winter tires in Sweden significantly increases tungsten concentrations in road runoff. Still, little is known about the geochemical cycling of tungsten in the environment as it has been considered to be a more or less inert element. Only a few studies deal with tungsten in natural waters. For example, for the Baltic Sea no concentration data have been published before this work and data on the suspended particulate fraction of tungsten in terrestrial and marine waters are scarce.

    This thesis contributes to the understanding of the distribution and behavior of tungsten, molybdenum and vanadium in natural waters under changing redox conditions, varying pH and different seasons. Particular attention is paid to the suspended particulate fraction of these elements, which is often neglected even though it can be of great importance. Tungsten, molybdenum and vanadium primarily occur as oxyanions in solution and can be adsorbed to particles, which determines their mobility.

    Molybdenum usually is very mobile, while vanadium has a tendency to adsorb to iron oxyhydroxides or to form organic complexes. Tungsten has many similarities with molybdenum, but it seems to be less mobile than molybdenum in natural waters.

    Tungsten and molybdenum have a similar abundance in the upper continental crust, but in the ocean molybdenum is almost 2000 times more abundant. A strong fractionation of these two elements occurs from land to the ocean, indicating a removal of W during mixing of river and seawater.

    This study comprises data from small streams in the boreal landscape of northern Sweden, major rivers (Kalix River and Råne River) and their estuaries discharging into the Baltic Sea. In the marine environment, sediment cores from the Bothnian Bay and water profiles at the stratified Landsort Deep have been studied. Apart from the spatial distribution, the temporal behavior of tungsten, molybdenum, and vanadium in was investigated. In the boreal environment snowmelt is playing a major role for their transport.

    All water samples were filtered through 0.22 pore size filters to define dissolved and suspended particulate fractions. The particulate fraction of all studied elements increases from streams to rivers. Especially during spring flood, particle transport becomes even more important. About 80% tungsten, 70% vanadium and 30% molybdenum occur in the particulate fraction during this event. During estuarine mixing, tungsten and molybdenum are released from the particles again. However, vanadium seems to be removed in both fractions, probably due to a different adsorption behavior. In the dissolved fraction molybdenum increased and vanadium decreased from land to the sea, while tungsten showed small variation in all surface waters.

    All three elements are affected by manganese redox cycling at the transition zone between oxic and sulfidic water at the Landsort Deep in the Baltic Sea. Adsorption of these oxyanions to the freshly formed manganese oxides plays an important role for their transport to the sulfidic zone. In contrast to molybdenum, dissolved tungsten is accumulated in the sulfidic environment. There is no effective removal mechanisms like for molybdenum, which is adsorbed to sulfides. Also in the sediment, redox cycling of manganese and iron affects the distribution of tungsten and molybdenum close to the water-sediment interface.

  • 38.
    Qu, Zhechao
    et al.
    Thermochemical Energy Conversion Laboratory (TEC-Lab), Department of Applied Physics and Electronics, Umeå University.
    Holmgren, Per
    Umeå University, Department of Applied Physics and Electronics, Thermochemical Energy Conversion Laboratory.
    Skoglund, Nils
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wagner, David R.
    Umeå University, Department of Applied Physics and Electronics, Thermochemical Energy Conversion Laboratory.
    Broström, Markus
    Thermochemical Energy Conversion Laboratory (TEC-Lab), Department of Applied Physics and Electronics, Umeå University.
    Schmidt, Florian M.
    Umeå University, Thermochemical Energy Conversion Laboratory, Department of Applied Physics and Electronics.
    Distribution of temperature, H2O and atomic potassium during entrained flow biomass combustion: Coupling in situ TDLAS with modeling approaches and ash chemistry2018In: Combustion and Flame, ISSN 0010-2180, E-ISSN 1556-2921, Vol. 188, 488-497 p.Article in journal (Refereed)
    Abstract [en]

    Tunable diode laser absorption spectroscopy (TDLAS) is employed for simultaneous detection of gas temperature, water vapor (H2O) and gas-phase atomic potassium, K(g), in an atmospheric, research-scale entrained flow reactor (EFR). In situ measurements are conducted at four different locations in the EFR core to study the progress of thermochemical conversion of softwood and Miscanthus powders with focus on the primary potassium reactions. In an initial validation step during propane flame operation, the measured axial EFR profiles of H2O density-weighted, path-averaged temperature, path-averaged H2O concentration and H2O column density are found in good agreement with 2D CFD simulations and standard flue gas analysis. During biomass conversion, temperature and H2O are significantly higher than for the propane flame, up to 1500 K and 9%, respectively, and K(g) concentrations between 0.2 and 270 ppbv are observed. Despite the large difference in initial potassium content between the fuels, the K(g) concentrations obtained at each EFR location are comparable, which highlights the importance of considering all major ash-forming elements in the fuel matrix. For both fuels, temperature and K(g) decrease with residence time, and in the lower part of the EFR, K(g) is in excellent agreement with thermodynamic equilibrium calculations evaluated at the TDLAS-measured temperatures and H2O concentrations. However, in the upper part of the EFR, where the measured H2O suggested a global equivalence ratio smaller than unity, K(g) is far below the predicted equilibrium values. This indicates that, in contrast to the organic compounds, potassium species rapidly undergo primary ash transformation reactions even if the fuel particles reside in an oxygen-deficient environment

  • 39.
    Urbán, Béla
    et al.
    University of Pannonia, Institute of Chemistry, Department of Organic Chemistry, Egyetem u, Hungary.
    Szabó, Péter
    University of Pannonia, Institute of Chemistry, Department of Analytical Chemistry, Egyetem u, Hungary.
    Srankó, Dávid
    Hungarian Academy of Sciences, Centre for Energy Research, Department of Surface Chemistry and Catalysis, Hungary.
    Sáfrán, György
    Hungarian Academy of Sciences, Research Institute for Technical Physics and Materials Science, Hungary.
    Kollár, László
    University of Pécs, Department of Inorganic Chemistry and MTA-PTE Research Group for Selective Chemical Syntheses, Hungary.
    Skoda-Földes, Rita
    University of Pannonia, Institute of Chemistry, Department of Organic Chemistry, Egyetem u, Hungary.
    Double carbonylation of iodoarenes in the presence of reusable palladium catalysts immobilised on supported phosphonium ionic liquid phases2018In: Molecular Catalysis, ISSN 2468-8231, Vol. 445, 195-205 p.Article in journal (Refereed)
    Abstract [en]

    The first heterogeneous carbonylation reaction carried out with palladium catalysts immobilised on phosphonium ion modified silica supports is reported. The supported ionic liquid phases were characterised by solid state NMR and FT-IR measurements. The presence of the phosphonium ions on the surface made it possible to carry out double carbonylation in apolar toluene efficiently that resulted in reduced metal leaching. The introduction of dicationic moieties on the solid support has been proved to lead to a further increase in catalyst stability. The catalysts were proved to produce α-ketoamide products with excellent selectivity in the carbonylation of iodoarenes with aliphatic amines while monocarbonylation was the only reaction observed with aniline derivatives. The catalysts could be recycled and used in at least 10 subsequent runs under optimised conditions.

  • 40.
    Shekhar, Gurmeet
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Draw control strategy for sublevel caving mines: A probabilistic approach2018Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Sublevel caving is an underground mass mining method used for extracting different types of ores from the earth crust. Mines using sublevel caving (SLC) as the primary mining method are generally highly mechanized with standardized and independent unit operations. Different unit operations (drilling, blasting, loading and transportation) are performed in isolation with each other which leads to standardized procedures and safe operation. Loading of the material from the production face in sublevel caving is facilitated by the flow of material under gravity into the production face. A large amount of material is loaded from a limited opening termed as the draw point which creates challenges for the mining method.

     

    Material flow in SLC has been studied extensively in the past five decades and different methods have been used to simulate material flow in caving operations. Physical models of different scales has been designed for simulating material flow by using sand, gravel or rocks and studying the movement of material inside the model. Initial physical models showed an ellipsoidal zone above the draw point from which material flowed into the draw point. However, subsequent physical modelling results disagreed with this notion of material flow. Numerical modelling techniques have also been applied to simulate material flow. Currently, marker trials are being used to understand material flow in SLC. Markers (numbered steel rods, RFID enabled markers) are installed in boreholes drilled inside the burden of a production ring and based on the recovery sequence of markers, material flow is predicted. Results from physical models, numerical models and marker trials along with mine experience have been used in the past to optimize mine design and draw control for SLC operation. The results from latest marker trials highlight the chaotic nature of material flow and the unpredictability associated with material flow simulation.

     

    In caving operations, draw control deals with the question of when to stop loading and regulates the loading process by providing the information on when to stop loading. The decision to stop loading a blasted ring and proceed to blasting the subsequent ring is a critical decision made in a SLC operation. If a draw point is closed early then ore is lost in the draw point which cannot be conclusively recovered at the lower levels and if delayed the mine faces greater dilution and increased mining costs. A study of the various draw control strategies used in sublevel caving operations globally has also been done to describe the present state-of-art. An analysis of the draw control and loading operations at the Malmberget and Kiirunavaara mines is summarized in the thesis using information collected through interviews, internal documents, meetings, and manuals. An optimized draw control strategy is vital for improving ore recovery and reducing dilution in SLC. Based on the literature review and baseline mapping study, a set of guidelines for designing a new draw control strategy has been listed. 

     

    In the present scenario of fluctuating metal prices and increasing operational cost a new draw control strategy is needed which is probabilistic in nature and can handle the uncertainties associated with caving operations. A draw control model which is probabilistic in nature provide a scenario based solution and can be used to test different draw control strategy before performing mine test. A framework for a probabilistic draw control model along with its application for draw control optimization has been discussed here. An effective draw control requires a constant monitoring system and a constant calibration of the loading criteria’s through draw point monitoring for reducing dilution and improving ore recovery.

  • 41.
    Pocorni, Jetro
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Powell, John
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Frostevarg, Jan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Kaplan, Alexander F. H.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Dynamic laser piercing of thick section metals2018In: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 100, 82-89 p.Article in journal (Refereed)
    Abstract [en]

    Before a contour can be laser cut the laser first needs to pierce the material. The time taken to achieve piercing should be minimised to optimise productivity. One important aspect of laser piercing is the reliability of the process because industrial laser cutting machines are programmed for the minimum reliable pierce time. In this work piercing experiments were carried out in 15 mm thick stainless steel sheets comparing a stationary laser and a laser which moves along a circular trajectory with varying processing speeds. Results show that circular piercing can decrease the pierce duration by almost half compared to stationary piercing. High speed imaging (HSI) was employed during the piercing process to understand melt behaviour inside the pierce hole. HSI videos show that circular rotation of the laser beam forces melt to eject in opposite direction of the beam movement, while in stationary piercing the melt ejects less efficiently in random directions out of the hole.

  • 42.
    Filippov, Andrei
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Azancheev, Nail
    Institute of Physics, Kazan Federal University, Kazan, Russia.
    Gibaydullin, Amal
    Institute of Physics, Kazan Federal University, Kazan, Russia.
    Bhattacharyya, Shubhankar
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Antzutkin, Oleg N.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Dynamic Properties of Imidazolium Orthoborate Ionic Liquids Mixed with Polyethylene Glycol Studied by NMR Diffusometry and Impedance Spectroscopy2018In: Magnetic Resonance in Chemistry, ISSN 0749-1581, E-ISSN 1097-458X, Vol. 56, no 2, 113-119 p.Article in journal (Refereed)
    Abstract [en]

    We used 1H pulsed field gradient (PFG) NMR to study the self-diffusion of polyethylene glycol (PEG) with average molecular mass of 200 and ions in mixtures of PEG with imidazolium bis(mandelato)borate (BMB) and imidazolium bis(oxalato)borate (BOB) ionic liquids (ILs). The ionic liquid was mixed with PEG in the concentration range of 0–100 wt%. Within the temperature range of 295 to 353 K, the diffusion coefficient of BMB is slower than that of the imidazolium cation. The diffusion coefficients of PEG, as well as the imidazolium cation and BMB anions, differ under all experimental conditions tested. This demonstrates that the IL in the mixture is present in at least a partially dissociated state. Generally, increasing the concentration of PEG leads to an increase in the diffusion coefficients of PEG and both the ions, and decreases their activation energy for diffusion. NMR chemical shift alteration analysis showed that the presence of PEG changes the chemical shifts of both ions but in different directions. Impedance spectroscopy was used to measure the ionic conductivity of the ionic liquids mixed with PEG.

  • 43.
    Tondera, Katharina (Editor)
    Stormwater Research Group, University of the Sunshine Coast, Maroochydore.
    Blecken, Godecke-Tobias (Editor)
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Chazarenc, Florent (Editor)
    Department of Energy Systems and Environment, Institut Mines Telecom Atlantique, Nantes cedex 3.
    Tanner, Chris C. (Editor)
    National Institute of Water and Atmospheric Research, Hamilton.
    Ecotechnologies for the Treatment of Variable Stormwater and Wastewater Flows2018Book (Refereed)
  • 44.
    Trischler, Johann
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Sandberg, Dick
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Dorn, Micheal
    Department of Building Technology, Linnæus University.
    Effect of temperature during vital gluten adhesive preparation and application on shear-bond strength2018In: Journal of Adhesion Science and Technology, ISSN 0169-4243, E-ISSN 1568-5616, Vol. 32, no 4, 448-455 p.Article in journal (Refereed)
    Abstract [en]

    If protein-based adhesives are to become a competitive bio-based alternative to synthetic adhesives, the preparation and application methods have to be considerable improved to reduce process time and thereby improve the economy of the adhesive system. The purpose of this study was to investigate the impact of the temperature during preparation and application on the shear-bond strength of an adhesive based on vital gluten for use in wood applications. Vital gluten was used in its natural form and mixed with water of different temperatures (preparation temperature 0 °C or 20 °C), and applied on beech veneer at different temperature (application temperature –10, 20, 60 and 100 °C). Tensile shear-bond strength samples were prepared and tested according to EN 205. The results showed that an increase in veneer temperature during application of the adhesive led to a decrease in the shear-bond strength, but that the preparation temperature of the adhesive had no influence on the strength.

  • 45.
    Khan, Amir Sada
    et al.
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Man, Zakaria
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Bustam, Mohamad Azmi
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Nasrullah, Asma
    Fundamental and Applied Science Department, Universiti Teknologi PETRONAS .
    Ullah, Zahoor
    Department of Chemistry, Balochistan University of IT, Engineering and Management Sciences (BUITEMS).
    Sarwono, Ariyanti
    Center of Research in Ionic Liquids, Department of Chemical Engineering, Universiti Teknologi PETRONAS .
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Muhammad, Nawshad
    Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore, Pakistan.
    Efficient Conversion of Lignocellulosic Biomass to Levulinic Acid Using Acidic Ionic Liquids2018In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 181, 208-214 p.Article in journal (Refereed)
    Abstract [en]

    In the present research work, dicationic ionic liquids, containing 1,1-Bis(3-methylimidazolium-1-yl) butylene ([C4(Mim)2]) cation with counter anions [(2HSO4)(H2SO4)0], [(2HSO4)(H2SO4)2] and [(2HSO4)(H2SO4)4] were synthesised. ILs structures were confirmed using 1H NMR spectroscopy. Thermal stability, Hammett acidity, density and viscosity of ILs were determined. Various types of lignocellulosic biomass such as rubber wood, palm oil frond, bamboo and rice husk were converted into LA. Among the synthesized ionic liquids, [C4(Mim)2][(2HSO4)(H2SO4)4] showed higher % yield of LA up to 47.52 from bamboo biomass at 100 °C for 60 min, which is the better yield at low temperature and short time compared to previous reports. Surface morphology, surface functional groups and thermal stability of bamboo before and after conversion into LA were studied using SEM, FTIR and TGA analysis, respectively. This one-pot production of levulinic acid from agro-waste will open new opportunity for the conversion of sustainable biomass resources into valuable chemicals.

  • 46.
    Åkerfeldt, Pia
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Hörnqvist Colliander, Magnus
    Department of Physics, Chalmers University of Technology.
    Pederson, Robert
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Engineering Science, University West.
    Antti, Marta-Lena
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Electron backscatter diffraction characterization of fatigue crack growth in laser metal wire deposited Ti-6Al-4V2018In: Materials Characterization, ISSN 1044-5803, E-ISSN 1873-4189, Vol. 135, 245-256 p.Article in journal (Refereed)
    Abstract [en]

    By additive manufacturing (AM) there is a feasibility of producing near net shape components in basically one step from 3D CAD model to final product. The interest for AM is high and during the past decade a lot of research has been carried out in order to understand the influence from process parameters on the microstructure and furthermore on the mechanical properties. In the present study laser metal wire deposition of Ti-6Al-4V has been studied in detail with regard to its fatigue crack propagation characteristics. Two specimen orientations, parallel and perpendicular to the deposition direction, have been evaluated at room temperature and at 250 °C. No difference in the fatigue crack growth rate could be confirmed for the two specimen orientations. However, in the fractographic study it was observed that the tortuosity varied between certain regions on the fracture surface. The local crack path characteristic could be related to the alpha colony size and/or the crystallographic orientation. Moreover, large areas exhibiting similar crystallographic orientation were observed along the prior beta grain boundaries, which were attributed to the wide alpha colonies frequently observed along the prior beta grain boundaries.

  • 47.
    Tondera, Katharina
    et al.
    Institute of Environmental Engineering, RWTH Aachen University, Aachen.
    Blecken, Godecke-Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Tournebize, Julien
    Hydrosystems and Bioprocessus Research Unit, Irstea—National Research Institute of Science and Technology for Environment and Agriculture, Antony.
    Viklander, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Andersson-Wikström, Alexandra
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Tanner, Chris C.
    National Institute of Water and Atmospheric Research, Hamilton.
    Emerging Contaminants: Occurrence, Treatment Efficiency and Accumulation Under Varying Flows2018In: Ecotechnologies for the Treatment of Variable Stormwater and Wastewater Flows / [ed] Katharina Tondera, Godecke-Tobias Blecken, Florent Chazarenc, Chris C. Tanner, Cham: Springer, 2018, 93-109 p.Chapter in book (Refereed)
    Abstract [en]

    Emerging contaminants became a major topic in water treatment when laboratory detection methods for concentrations at a nanogram-scale improved approximately two decades ago. Research on using ecotechnologies to remove emerging contaminants in variable stormwater and wastewater flows has been conducted for more than a decade, but so far, not all removal mechanisms are well understood and only few setups have been investigated. This chapter summarises the current knowledge, focussing on pesticides and emerging contaminants listed on the watch list of the European Union. However, large-scale investigations are still rare and further research will have to be conducted in this field to enable practitioners to provide recommendations for design and maintenance of treatment facilities in the field of ecotechnologies.

  • 48.
    Yamauchi, Masatoshi
    et al.
    Swedish Institute of Space Physics, Kiruna.
    Slapak, Rikard
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Energy conversion through mass loading of escaping ionospheric ions for different Kp values2018In: Annales Geophysicae, ISSN 0992-7689, E-ISSN 1432-0576, Vol. 36, no 1, 1-12 p.Article in journal (Refereed)
    Abstract [en]

    By conserving momentum during the mixing of fast solar wind flow and slow planetary ion flow in an inelastic way, mass loading converts kinetic energy to other forms-e.g. first to electrical energy through charge separation and then to thermal energy (randomness) through gyromotion of the newly born cold ions for the comet and Mars cases. Here, we consider the Earth's exterior cusp and plasma mantle, where the ionospheric origin escaping ions with finite temperatures are loaded into the decelerated solar wind flow. Due to direct connectivity to the ionosphere through the geomagnetic field, a large part of this electrical energy is consumed to maintain field-aligned currents (FACs) toward the ionosphere, in a similar manner as the solar wind-driven ionospheric convection in the open geomagnetic field region. We show that the energy extraction rate by the mass loading of escaping ions (δK) is sufficient to explain the cusp FACs, and that 1K depends only on the solar wind velocity accessing the mass-loading region (usw) and the total mass flux of the escaping ions into this region (mloadFload), as δK ∼-mloadFloadu2 sw=4. The expected distribution of the separated charges by this process also predicts the observed flowing directions of the cusp FACs for different interplanetary magnetic field (IMF) orientations if we include the deflection of the solar wind flow directions in the exterior cusp. Using empirical relations of μ 0α KpC1:2 and Fload/exp.0:45Kp/for Kp D 1-7, where u0 is the solar wind velocity upstream of the bow shock, δK becomes a simple function of Kp as log10.δK/log10 0:2 &dw=elta;KpC 2 log10.KpC1:2)+Cconstant. The major contribution of this nearly linear increase is the Fload term, i.e. positive feedback between the increase of ion escaping rate Fload through the increased energy consumption in the ionosphere for high Kp, and subsequent extraction of more kinetic energy 1K from the solar wind to the current system by the increased Fload. Since Fload significantly increases for increased flux of extreme ultraviolet (EUV) radiation, high EUV flux may significantly enhance this positive feedback. Therefore, the ion escape rate and the energy extraction by mass loading during ancient Earth, when the Sun is believed to have emitted much higher EUV flux than at present, could have been even higher than the currently available highest values based on Kp D 9. This raises a possibility that the ion escape has substantially contributed to the evolution of the Earth's atmosphere.

  • 49.
    Parisio, Alessandra
    et al.
    School of Electrical and Electronic Engineering, The University of Manchester.
    Molinari, Marco
    School of Electrical Engineering, KTH Royal Institute of Technology, Stockholm.
    Varagnolo, Damiano
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Johansson, Karl H.
    ACCESS Linnaeus Centre, School of Electrical Engineering, KTH Royal Institute of Technology, Stockholm.
    Energy Management Systems for Intelligent Buildings in Smart Grids2018In: Intelligent Building Control Systems: A Survey of Modern Building Control and Sensing Strategies / [ed] John T. Wen, Sandipan Mishra, Cham: Springer, 2018, 253-291 p.Chapter in book (Refereed)
    Abstract [en]

    The next-generation electric grid needs to be smart and sustainable to simultaneously deal with the ever-growing global energy demand and achieve environmental goals. In this context, the role of residential and commercial buildings is crucial, due to their large share of primary energy usage worldwide. In this chapter, we describe energy management frameworks for buildings in a smart grid scenario. An Energy Management System (EMS) is responsible for optimally scheduling end-user smart appliances, heating systems, ventilation units, and local generation devices. We discuss the performance and the practical implementation of novel stochastic MPC schemes for HVAC systems, and illustrate how these schemes take into account several sources of uncertainties, e.g., occupancy and weather conditions. Furthermore, we show how to integrate local generation capabilities and storage systems into a holistic building energy management framework.

  • 50.
    Jagers, Sverker
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Harring, Niklas
    Department of Political Science, University of Gothenburg.
    Matti, Simon
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Environmental management from left to right: on ideology, policy-specific beliefs and pro-environmental policy support2018In: Journal of Environmental Planning and Management, ISSN 0964-0568, E-ISSN 1360-0559, Vol. 61, no 1, 86-104 p.Article in journal (Refereed)
    Abstract [en]

    Due to growing environmental challenges, the demand for effective management through pro-environmental policy measures is increasing. The effectiveness is, however, largely determined by the degree to which the policy measures are supported by the actors affected by them. A consistent finding in the literature is that ideology (or subjective positioning on the left–right dimension) affects environmental policy support, with left-leaning individuals being more pro-environmental. A major caveat with previous research is that it seldom makes a distinction between different kinds of policies. Therefore, we are concerned with investigating how different ideological positions affect attitudes towards different forms of environmental protection. Using unique survey data, we show that ideology is related to conceptions about the fairness and effectiveness of different policy tools, which in turn steer preferences. In that sense, this paper makes the discussion on the effects of ideological position on pro-environmental policy support more nuanced.

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