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  • 1.
    Wimo, Anders
    et al.
    Aging Research Centre, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet .
    Jönsson, Linus
    Aging Research Centre, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet.
    Fratiglioni, Laura
    Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Huddinge .
    Sandman, Per-Olof
    Luleå University of Technology, Department of Health Sciences, Nursing Care.
    Gustavsson, Anders
    Aging Research Centre, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet.
    Sköldunger, Anders
    Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Huddinge.
    Johansson, Lennarth
    Stockholm Gerontology Research Centre.
    Erratum to: The societal costs of dementia in Sweden 2012: relevance and methodological challenges in valuing informal care2019In: Alzheimer's Research & Therapy, ISSN 0065-6755, E-ISSN 1758-9193, Vol. 9, no 1, 12Article in journal (Refereed)
    Abstract [en]

    During production of the original article [1], the line referring to “Informal Care” was omitted from Table 3. It should have been mentioned between “Total social care sector” and “Indirect costs”.

  • 2.
    D'Orazio, Christian Javier
    et al.
    School of Information Technology and Mathematical Sciences, University of South Australia, Australia.
    Rongxing, Lu
    Faculty of Computer Science, University of New Brunswick, Fredericton, NB, Canada.
    Choo, Kim Kwang Raymond
    School of Information Technology and Mathematical Sciences, University of South Australia, Australia.
    Vasilakos, Athanasios
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    A Markov adversary model to detect vulnerable iOS devices and vulnerabilities in iOS apps2017In: Applied Mathematics and Computation, ISSN 0096-3003, E-ISSN 1873-5649, Vol. 293, 523-544 p.Article in journal (Refereed)
    Abstract [en]

    With the increased convergence of technologies whereby a user can access, store and transmit data across different devices in real-time, risks will arise from factors such as lack of appropriate security measures in place and users not having requisite levels of security awareness and not fully understanding how security measures can be used to their advantage. In this paper, we adapt our previously published adversary model for digital rights management (DRM) apps and demonstrate how it can be used to detect vulnerable iOS devices and to analyse (non-DRM) apps for vulnerabilities that can potentially be exploited. Using our adversary model, we investigate several (jailbroken and non-jailbroken) iOS devices, Australian Government Medicare Expert Plus (MEP) app, Commonwealth Bank of Australia app, Western Union app, PayPal app, PocketCloud Remote Desktop app and Simple Transfer Pro app, and reveal previously unknown vulnerabilities. We then demonstrate how the identified vulnerabilities can be exploited to expose the user's sensitive data and personally identifiable information stored on or transmitted from the device. We conclude with several recommendations to enhance the security and privacy of user data stored on or transmitted from these devices.

  • 3.
    Alvarez Perez, Manuel Alejandro
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Stochastic Planning of Smart Electricity Distribution Networks2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The penetration of intermittent Distributed Generation (DG) brought additional uncertainty to the system operation and planning. To cope with uncertainties the Distribution System Operator (DSO) could implement several strategies. These strategies range from the inclusion of smart technologies which will increment system’s flexibility and resiliency, to improvements in forecasting, modeling, and regulatory pledge that will facilitate the planning activity. Regardless of the nature of the solutions, they could be collected in a sort of toolbox. The planner will access the toolbox to conform cost effective plans, better able to deal with any uncertainty. The present work will address the problem of distribution system planning under uncertainties, considering smart solutions along with traditional reinforcements, in the short-term lead time up to 3 years ahead. The work will be focused on three aspects that are the cornerstones of this work:

     • A planning facilitating strategy: Distribution Capacity Contracts (DCCs).

     • A flexibility enabler technology: Energy Storage.

     • A binding methodology: Multistage Stochastic Programming. Stochastic dual dynamic programming (SDDP). 

    Under the present directive of the European Parliament concerning common rules for the internal market in electricity, distribution companies are not allowed to own DG but entitled to include it as a planning option to differ investment in traditional grid reinforcements. An evaluation of the regulatory context will lead this work to consider DCCs as a planning alternative available in the toolbox. The impact of this type of contract on the remuneration of the DG owner will be assessed in order to provide insight on its willingness to participate. The DCCs might aid the DSO to defer grid i ii investments during planning stages and to control the network flows during operation. 

    Given that storage solutions help to match in time production from intermittent sources with load consumption, they will play a major role in dealing with uncertainties. A generic storage model (GSM) based on a future cost piecewise approximation will be developed. This model inspired by hydro-reservoirs will help assessing the impact of storage in planning decisions. This model will be tested by implementing it in short-term hydro scheduling and unit commitment studies. 

    To trace a path towards the future of this research work, a discussion on the planning problem formulation, under consideration of the lead time, the expansion options, the smart strategies, and the regulatory framework will be presented. Special focus will be given to multistage stochastic programming methods and in particular to the SDDP approach.

  • 4.
    Grip, Niklas
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mathematical Science.
    Sabourova, Natalia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Tu, Yongming
    School of Civil Engineering, Southeast University, Nanjing.
    Sensitivity-based model updating for structural damage identification using total variation regularization2017In: Mechanical systems and signal processing, ISSN 0888-3270, E-ISSN 1096-1216, Vol. 84, no A, 365-383 p.Article in journal (Refereed)
    Abstract [en]

    Sensitivity-based Finite Element Model Updating (FEMU) is one of the widely accepted techniques used for damage identification in structures. FEMU can be formulated as a numerical optimization problem and solved iteratively making automatic updating of the unknown model parameters by minimizing the difference between measured and analytical structural properties. However, in the presence of noise in the measurements, the updating results are usually prone to errors. This is mathematically described as instability of the damage identification as an inverse problem. One way to resolve this problem is by using regularization. In this paper, we compare a well established interpolation-based regularization method against methods based on the minimization of the total variation of the unknown model parameters. These are new regularization methods for structural damage identification. We investigate how using Huber and pseudo Huber functions in the definition of total variation affects important properties of the methods. For instance, for well-localized damages the results show a clear advantage of the total variation based regularization in terms of the identified location and severity of damage compared with the interpolation-based solution.For a practical test of the proposed method we use a reinforced concrete plate. Measurements and analysis were performed first on an undamaged plate, and then repeated after applying four different degrees of damage.

  • 5.
    Saintilan, Nicholas J.
    et al.
    Section of Earth and Environmental Sciences, University of Geneva.
    Stephens, Michael
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Spikings, Richard A.
    Section of Earth and Environmental Sciences, University of Geneva.
    Schneider, Jens C.
    Department of Mineralogy, Technische Universität Bergakademie Freiberg.
    Chiaradia, Massimo
    Section of Earth and Environmental Sciences, University of Geneva.
    Spangenberg, Jorge E.
    Institute of Earth Surface Dynamics, University of Lausanne.
    Ulianov, Alexey
    Institute of Earth Sciences, University of Lausanne.
    Fontboté, Lluis
    Section of Earth and Environmental Sciences, University of Geneva.
    Polyphase vein mineralization in the Fennoscandian Shield at Åkerlandet, Järvsand, and Laisvall along the erosional front of the Caledonian orogen, Sweden2017In: Mineralium Deposita, ISSN 0026-4598, E-ISSN 1432-1866Article in journal (Refereed)
    Abstract [en]

    The Åkerlandet, Järvsand, and Laisvall deposits in Sweden are calcite-fluorite-sulfide vein deposits and occurrences located close to the current erosional front of the Caledonian orogen and hosted by crystalline basement rocks in the Fennoscandian Shield. At Laisvall, basement-hosted veinlets occur beneath Ediacaran to Cambrian sandstones that host a strata-bound Pb-Zn deposit. The mineralized fractures at Åkerlandet and Järvsand occur along fault systems oriented N–S to NNW–SSE. Veins or veinlets strike NNW–SSE and NW–SE at Åkerlandet, NNE–SSW at Järvsand, and NNW–SSE and NNE–SSW to NE–SW at Laisvall. At Åkerlandet and Järvsand, fractures acted as conduits for hydrothermal fluids of variable composition and formed during separate tectonic events. At Åkerlandet, the fault zone with NNW–SSE strike shows kinematic indicators consistent with ~NE–SW bulk horizontal extension. At Järvsand, the calcite-fluorite-galena veins formed along R-Riedel shears related to the host N–S to NNW–SSE fault system. The kinematic indicators are consistent with ~NW–SE bulk horizontal extension, similar to the extensional deformation during the later part of the Caledonian orogeny (Silurian to Devonian). At Åkerlandet, adularia-quartz deposition was followed by sphalerite ± galena and finally by precipitation of fluorite and calcite. 40Ar-39Ar thermochronology of a single adularia sample did not yield a well-defined plateau age but the gas released at higher temperatures suggests an early Tonian (980 to 950 Ma) crystallization age, i.e., during the later part of the Sveconorwegian orogeny, although the data do not exclude other less likely interpretations. Previous fluid inclusion microthermometry and geochronological studies and new petrographic and geochemical results suggest that sphalerite ± galena mineralization formed from saline, relatively oxidizing, moderate-temperature, and slightly acidic hydrothermal fluids, either during the Ediacaran or the Middle Ordovician. Metals and H2S were derived from local basement rocks. Based on petrographic evidence, rare earth element composition, and S, C, and O isotope data, fluorite and calcite precipitated under near neutral and relatively reducing conditions. Occurrence of solid bitumen in veins at Åkerlandet and C and O isotope data of calcite at Åkerlandet and in the Laisvall basement veinlets suggest that the precipitation of calcite and fluorite was triggered by interaction of hot and evolved hydrothermal fluids (87Sr/86Sr = 0.718–0.732) with organic matter. Structural, petrographic, and geochemical data at Laisvall suggest that the basement structures hosting calcite-fluorite ± pyrite veinlets were utilized in the Middle Ordovician as the plumbing system for the oxidizing, slightly acidic, metal-bearing brines that caused the economic Pb-Zn mineralization in the overlying sandstones

  • 6.
    Chibba, Aron
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Supply Chain Quality Management - Exploring performance of manufacturing organizations2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis addresses the issue of quality performance in supply chains in the manufacturers’context. Research shows that the management and performance of supply chains play a major rolein gaining competitive advantage, especially in times of decreasing international trade barriers andquickly evolving information technology. Some researchers claim that it is the supply chain itselfthat competes on a market and not merely the organisations with their specific strategies andgoals. Supply chain performance has been widely discussed in the research literature in recentyears. However, this research points out that supply chain quality management (SCQM) and itsimpact on firm performance (both inter-organisational and intra-organisational) have not beensufficiently understood. Further studies are needed to identify the direct and indirect impact ofSCQM practices on firm performance at multiple levels.A problem that many organisations face is the lack of resources and knowledge on how to managesupply chain quality performance (i.e., which performance to measure, how to controlperformance, and how to improve performance). Studies show that often even large companiesmeasure effectiveness using key performance indicators (KPI) and that these indicators often donot depict key characteristics critical to organisational performance or customer behaviour.Therefore, such indicators might be inadequate for fully capturing the performance of supplychains. As quality management standards evolve, managers need to adapt to changingrequirements. To fulfil the new version of ISO 9001, organisations are required to determinecriteria and apply methods to ensure effective operation and control of their processes (both intraorganisationaland inter-organisational performance). This includes monitoring and measuringperformance indicators. The quality performance of a supply chain is dependent on its ability toimprove and thereby enable organisations to stay competitive over time. Good measurements ofsupply chain quality performance must reflect this ability. To do so, organisations need to knowwhich measures and metrics to use and how to analyse performance of their supply chains.From the seven studies presented in this thesis we are able to draw a number of more generalconclusions that bear on the main research question: What improves quality performance of supplychains that include manufacturing? At the process level, it has been found that manufacturersshould focus on the quality and delivery performance of each process within the organisation. Atthe internal, integrated supply chain level, a manufacturing organisation should focus on quality(conformance), delivery performance (on-time delivery), and cost cutting in the internal supplychain. Collaboration using cross-functional teams seems most appropriate when working withproduct development. The use of a process-oriented mapping tool was found to facilitatedescription of information flows and physical material flows and also to identify disturbances thatcould be improved and rationalized to generate a better flow in the total supply chain. At both theupstream and downstream sides of the supply chain, one-sided measures that depict performanceover organisational boundaries were found to be the most common. At the downstream side of asupply chain, suppliers could be chosen based on cost, conformance, speed, and flexibility. At theupstream side, procedures that handle changing requirements and information about delays orincorrectness of materials were found to influence flow. The results from these seven studies arethe basis for the development of a supply chain quality improvement model. In the literature,supply chain performance is often discussed on a strategic level with measures for quality,flexibility and delivery. Managers also need metrics that can be followed up on at a detailed level(e.g., capacity load, breakdown rates, claims, cost of poor quality, and lead-times). To bridge thisgap, a Key Performance Indicators Matrix of supply chain quality performance indicators formanufacturers is proposed.

  • 7.
    Qarahasanlou, Ali Nouri
    et al.
    Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology, .
    Khalokakaie, Reza
    Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology, .
    Ataei, Mohammad
    Faculty of Mining, Petroleum & Geophysics, Shahrood University of Technology, .
    Ghodrati, Behzad
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Operating Environment-Based Availability Importance Measures for Mining Equipment: (Case Study: Sungun Copper Mine)2017In: Journal of Failure Analysis and Prevention, ISSN 1547-7029, E-ISSN 1864-1245, Vol. 17, no 1, 56-67 p.Article in journal (Refereed)
    Abstract [en]

    When a system’s performance is inadequate, the concept of availability importance can be used to improve it. The availability of an item depends on the combined aspects of its reliability and maintainability. In a system consisting of many subsystems, the availability of some subsystems is more important to system performance than others. The availability measure determines the priority of availability across subsystems. Most researchers only consider operation time and ignore the influence of the operating environment; therefore, their estimations are not accurate enough. In contrast to previous research, we focus on the influence of the operating environment on the system/subsystem’s characteristics with a view to prioritizing them based on the importance of availability. The paper considers part of the mining fleet system of Sungun copper mine, including the wagon drill, loader, bulldozer, and dump truck subsystems. We identify an ordered list of possibilities for availability improvement and suggest changes or remedial actions for each item to either reduce its failure rate or reduce the time required to repair it.

  • 8.
    Lidström Brock, Malin
    Luleå University of Technology, Department of Arts, Communication and Education, Education, Language, and Teaching.
    Writing Feminist Lives: The Biographical Battles over Betty Friedan, Germaine Greer, Gloria Steinem, and Simone de Beauvoir2017Book (Refereed)
    Abstract [en]

    This book draws attention to the controversy that surrounds Betty Friedan, Germaine Greer, Gloria Steinem, and Simone de Beauvoir’s lives and the important role that their life stories have played in their feminist writing. Directly and indirectly, the four women have contributed to battles over feminism’s meaning through autobiographically informed political writing. Inevitably, therefore, their biographers are also participants in these battles, yet not always on the same side as their subjects. Writing Feminist Lives introduces a further fold of nuance into considerations of biography and feminism by showing that the biographers of the four women have made methodological choices that reflect their loyalty to, or their scepticism towards, competing ideological definitions of the exemplary feminist life. 

  • 9.
    Khoshkhoo, Mohammad
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Dopson, Mark
    Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University.
    Engström, Fredrik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    Sandström, Åke
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Minerals and Metallurgical Engineering.
    New insights into the influence of redox potential on chalcopyrite leaching behaviour2017In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 100, 9-16 p.Article in journal (Refereed)
    Abstract [en]

    Chalcopyrite (CuFeS2) is the most economically important and most refractory copper mineral when treated in conventional sulphate media leaching systems. In this study, the effect of solution redox potential on leaching of a pure and a pyritic chalcopyrite concentrate was investigated using concentrates with fresh and aged surfaces. In experiments using concentrates with fresh surfaces, the response to redox potential depended on the presence of pyrite: fresh pyritic concentrate leached more effectively at low redox potential (in agreement with reductive leaching mechanisms), while the leaching efficiencies from fresh pure concentrate were similar at high and low redox potentials. The data suggested that the reductive leaching mechanism does not necessarily result in higher and faster recoveries in the absence of the galvanic interaction induced by the presence of pyrite. It was also found that exposure of chalcopyrite to atmospheric oxidation prior to leaching (ageing) had an effect on leaching behaviour in response to redox potential: copper recoveries in leaching of aged concentrates were higher at high redox potentials. This behaviour was attributed to the presence of iron–oxyhydroxides on the surface of aged concentrates. Based on the data from this investigation and previous surface studies, it is proposed that iron–oxyhydroxides play an important role in triggering the hindered dissolution of chalcopyrite.

  • 10.
    Ma, Chunyan
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science. College of Chemical Engineering, Nanjing Tech University.
    Guo, Yanhua
    College of Chemical Engineering, Nanjing Tech University.
    Li, Dongxue
    College of Chemical Engineering, Nanjing Tech University.
    Zong, Jianpeng
    College of Chemical Engineering, Nanjing Tech University.
    Ji, Xiaoyan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Liu, Chang
    College of Chemical Engineering, Nanjing Tech University.
    Molar enthalpy of mixing and refractive indices of choline chloride-based deep eutectic solvents with water2017In: Journal of Chemical Thermodynamics, ISSN 0021-9614, E-ISSN 1096-3626, Vol. 105, 30-36 p.Article in journal (Refereed)
    Abstract [en]

    The molar enthalpies of mixing were measured for binary systems of choline chloride-based deep eutectic solvents (glycerol, ethylene glycol and malonic acid) with water at 298.15 K and 308.15 K, and atmospheric pressure with an isothermal calorimeter. Refractive indices were also measured at 303.15 K and atmospheric pressure. The binary mixtures of {chcl/glycerol (1:2) + water, chcl/ethylene glycol (1:2) + water} showed exothermic behaviour over the entire range of composition, while the binary mixture of {chcl/malonic acid (1:1) + water} showed endothermic behaviour at first and then changed to be exothermic with the increasing content of chcl/malonic acid (1:1). Experimental refractive indices were fitted with the Redlich–Kister equation, and experimental molar enthalpies of mixing were correlated with the Redlich–Kister equation and the non-random two-liquid (NRTL) model. The NRTL model with the fitted parameters was used to predict the vapour pressures of these three mixtures. For mixtures of {chcl/glycerol (1:2) + water} and {chcl/ethylene glycol (1:2) + water}, the predicted vapour pressures agreed well with the experimental reults from the literature. While for mixture of {chcl/malonic acid (1:1)+water}, the predicted vapour pressures showed deviation at the high concentration of chcl/malonic acid (1:1), and this was probably because of the complex molecular interaction between chcl/malonic acid (1:1) and water

  • 11.
    Sanda, Mohammed-Aminu
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Dynamics of National Culture and Employee Characteristics on Organizational Commitment in Retail Banks in Ghana2017In: Advances in Cross-Cultural Decision Making: Proceedings of the AHFE 2016 International Conference on Cross-Cultural Decision Making (CCDM), July 27-31,2016, Walt Disney World®, Florida, USA / [ed] Sae Schatz; Mark Hoffman, London: Encyclopedia of Global Archaeology/Springer Verlag, 2017, 71-83 p.Conference paper (Refereed)
    Abstract [en]

    Firms operating in high growth sectors are known to face the challenges of hiring and assimilating large numbers of new employees, providing new knowledge and skills to existing employees, and addressing the need for a rapid expansion of leadership capability. In the Ghanaian situation, such a challenge is known to prevail, since the country implemented major financial sector reforms starting in the late 1980s as part of its broad market reforms, key of which is the deregulation of the financial sub-sector. The banking sector in Ghana is therefore, faced with human resource management challenges, which includes the finding of the right caliber of employees to employ, and how to ensure that employees get committed to their organizations in order to reduce their desire to switch to competitor firms, due to apparent dissatisfaction with their jobs. This study therefore, examined a conceptual model that sought to hypothesize the impact of national culture and employee characteristics on employees’ organizational commitment in retail banks in Ghana. The purpose is to understand the extent to which Ghanaian national cultural values and employee characteristics impact on employee organizational commitment in Retail Banks operating in Ghana. Quantitative data was collected from 282 bank employee across nine different retail banks in Ghana, and analyzed stepwise, using the analysis of moment structures (AMOS) program. Firstly, path analysis was conducted to test the individual measurement models that constitute the various components of the conceptual structural model. In this analysis, the factor score weights and model fit estimates for the indicator variables in the various latent variables (i.e. national culture, employee characteristics, and organizational commitment,) were appraised. Results from the path analysis identified four measurable indicators for organizational commitment. The analysis showed that all the measurable indicators tested for national culture and employee characteristics did not have significant loads to serve as measurable indicators. It is concluded that employees’ organizational commitment in retail banks in Ghana is neither influenced by the Ghanaian national culture nor the employee’s characteristics.

  • 12.
    Rogdakis, Ioannis
    et al.
    School of Production Engineering and Management, Technical University of Crete.
    Marinaki, Magdalene
    School of Production Engineering and Management, Technical University of Crete.
    Marinakis, Yannis
    School of Production Engineering and Management, Technical University of Crete, Decision Support Systems Laboratory, Department of Production Engineering and Management, Technical University of Crete.
    Migdalas, Athanasios
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    An Island Memetic Algorithm for Real World Vehicle Routing Problems2017In: Operational Research in Business and Economics: 4th International Symposium and 26th National Conference on Operational Research, Chania, Greece, June 2015 / [ed] Evangelos Grigoroudis ; Michael Doumpos, Encyclopedia of Global Archaeology/Springer Verlag, 2017, 205-223 p.Conference paper (Refereed)
    Abstract [en]

    In this paper, a new algorithm is presented which is applied to a real world Vehicle Routing Problem (VRP) of a provision company in the island of Crete in Greece. The company serves 116 customers located in Crete. This real world problem is solved effectively by a hybrid Island Memetic Algorithm (IMA) which employs Greedy Randomized Adaptive Search Procedure (GRASP) and Iterated Local Search (ILS). The proposed algorithm is also compared to five other approaches both on the real world problem and on classic benchmark instances from the literature. Methods such as GRASP, local search and Iterated Local Search (ILS) are employed as subroutines with certain probabilities in the algorithms. Furthermore, it is also demonstrated how premature convergence can be prevented by adopting specific strategy. Computational results show the superiority of the proposed hybrid Island Memetic Algorithm

  • 13.
    Sanda, Mohammed Aminu
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    An organizational activity framework for effective business practices implementation in research-oriented organizations in developing economies2017In: Advances in Human Factors, Business Management, Training and Education: Proceedings of the AHFE 2016 International Conference on Human Factors, Business Management and Society, July 27-31, 2016, Walt Disney World®, Florida, USA / [ed] Jussi Ilari Kantola; Tibor Barath; Salman Nazir; Terence Andre, London: Encyclopedia of Global Archaeology/Springer Verlag, 2017, 993-1006 p.Conference paper (Refereed)
    Abstract [en]

    This paper explored the constraints to business practices implementation by Research-Oriented Organizations in Developing Economies. Guided by organizational activity, sociotechnical and macroergonomic theories, data was collected from four research-oriented organizations in four developing countries, and analyzed using actions of identified groups in each organization’s activity system as the unit of analysis. It was found that the emergence of multivoicedness in the organizations’ activity systems created misfits among the organizations components which created systemic problems, ruptures, and breakdowns which constrained the effectiveness of the organizations’ business practices implementations. It is concluded that in the process of business practices implementation, an activity in the organization must be understood not as one activity with its peculiarities, but rather as a real aggregate of several activities and relations arising from the interacting components of the organization. A framework for understanding effective business practices implementation in research-oriented organizations is thus formulated.

  • 14.
    Duenas Dobrowolski, Jan
    et al.
    Wrocław University of Science and Technology.
    Gawlinski, Marek
    Department of Design Fundamentals and Fluid-Flow Machinery, Wrocław University of Technology.
    Paszkowski, Maciej
    Department of Fundamentals of Machine Design and Tribology, Wrocław University of Technology.
    Westerberg, Lars-Göran
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Experimental study of lubricating grease flow inside the gap of a labyrinth seal using micro Particle Image Velocimetry2017In: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397XArticle in journal (Refereed)
    Abstract [en]

    In this study the flow of lubricating greases in a labyrinth seal geometry is studied using micro Particle Image Velocimetry (µPIV). The aim is to evaluate the grease velocity distribution inside the gap of a labyrinth seal and to find a relationship between the grease consistency and the transferred speed from the rotating ring in order to choose the correct grease as a sealing medium. Also, the grease flow characteristics are important for the understanding of fracture due to grease layer displacement. For these purposes, four greases with different rheological properties were used in µPIV experiments. It was found that not only the grease consistency plays a crucial role in speed development but also the grease composition and the slip effect presence at the grease-rotating wall interface.

  • 15.
    Sanda, Mohammed Aminu
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Charismatic influence and organizing capability as unique managerial self-efficacies for effective small firm performance in developing economy2017In: Advances in Human Factors, Business Management, Training and Education: Proceedings of the AHFE 2016 International Conference on Human Factors, Business Management and Society, July 27-31, 2016, Walt Disney World®, Florida, USA / [ed] Jussi Ilari Kantola; Tibor Barath; Salman Nazir; Terence Andre, London: Encyclopedia of Global Archaeology/Springer Verlag, 2017, 419-431 p.Conference paper (Refereed)
    Abstract [en]

    In the past two decades, changes in the industrial environment of most developing countries and the increasing competition among firms has greatly influenced executives’ attitudes and behaviours in the effective management of their firms. There is evidence in the extant literature that the sustained superior performances of most firms is attributable to the unique capabilities used in managing their human resources, and which capabilities are rare, valuable, non-substitutable and imitable. This study therefore, explored the requisite self-efficacies that are exhibited by executives of small firms in Ghana in their day-to-day management of their businesses that leads to increase firm performance, since such self-efficacies are human-oriented capabilities that are rare, valuable, non-substitutable and imitable. This was necessitated by the observation that most executives of small firms in Ghana have not been able to achieve much for their firms, in terms of increasing their businesses productive efficiencies and effectiveness, because the requisite self-efficacies required of such executives for improved performances are unknown and unexplored. Guided by the self-efficacy theorization, data was collected from executives of seventy-two small firms in Ghana using a standardised questionnaire. Factor analysis was conducted to identify the plausible factors with the requisite weight to predict the executives’ self-efficacy, and the attribution of such factors. The factor analyses, with Kaiser-Meyer-Olkin as well as Bartlett’s tests, were initiated to measure the factorability of the data, using the statistical package for the social sciences (SPSS) as the analytic tool. Principal Component Analysis was then used as a data reduction technique using the Rotation Method (Varimax with Kaiser Normalization). Indicator predictiveness was interpreted using Schumacker and Lomax’s (2004) recommendation that estimated factor loading must be 0.7 or higher. Based on the analysis, it is found that the executives of small firms in Ghana exhibit self-efficacies which they manifest variously as charismatic influences and organizing capabilities. The executives showed high levels of organizing capabilities and charismatic influences on the work they manage as a result of their self-efficacies. It is also found that the self-efficacy indicators reflecting the executives’ exertion of charismatic influences on their employees correlated significantly with their self-efficacy indicators reflecting their capabilities to organize their firms’ activities. It is concluded that the executives’ use of their charismatic influence-oriented and organizing capability-oriented self-efficacies has a positive influence on their abilities to manage their small firms. It is also concluded that, the executives ability to handle the time demands and the paper work required of their managerial jobs, on the one hand, and their ability to maintain control of their personal daily schedule, and cope with the stress aspect of their managerial job, on the other, had a direct positive impact on their abilities to carry out the following functions. The findings in this study contribute to knowledge in the management of small firms. Specifically, for Ghana, this research provides a platform for the development of a database that will help inform policy-makers on the requisite self-efficacies to be required of small firms’ executives in the daily management of their businesses.

  • 16.
    Sanda, Mohammed-Aminu
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Cognitive and Emotional-Motivational Implications in the Job Design of Digitized Production Drilling in Deep Mines2017In: Advances in Neuroergonomics and Cognitive Engineering: Proceedings of the AHFE 2016 International Conference on Neuroergonomics and Cognitive Engineering, July 27-31, 2016, Walt Disney World®, Florida, USA / [ed] Kelly S. Hale; Kay M. Stanney, London: Encyclopedia of Global Archaeology/Springer Verlag, 2017, 211-222 p.Conference paper (Refereed)
    Abstract [en]

    The aim of this paper was to understand the influence of cognitive and emotional-motivational aspects of task complexity on workers performances in high-technology driven drilling activity in a deep mine. Data was collected by observing and video recording miners’ engaged in two separate production drilling activities, using two Boomers simultaneously. Based on the analysis, it is found that the workers encounter cognitive challenges in their ability to process information marked on rock surfaces for the positioning of the boomers, resulting in added complexity to their drilling tasks. The workers’ were also found to have issues with the quality of their designed job environment, and which emotional-motivational challenge also added to their tasks complexity. It is concluded that by understanding the emerging cognitive and emotional-motivational aspects of task complexities, future design processes of a friendly and performance enhancing work environments and technologies could evolve for efficient and effective human work.

  • 17.
    Hjulman, Tore Andersson
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    Ett med naturen: En studie av hur naturen omförhandlades i mellankrigstidens konflikter mellan naturskydd och samiska rättigheter2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Tore Andersson Hjulman: One with Nature: An Inquiry into the Renegotiation of Nature in the Conflicts between Nature Preservation and Sámi Rights during the Interwar Period.[Ett med naturen: En studie av hur naturen omförhandlades i mellankrigstidens konflikter mellan naturskydd och samiska rättigheter.] PhD dissertation in Swedish, Luleå University of Technology, Sweden 2017.

    In 1909 the Swedish national parks law was adopted with the assumption that theSámi people living in the areas to be preserved were, in principle, one with nature. Therefore the perception of their land as pristine was consolidated and they could be excepted from park regulations. About thirty years later the national park administration stated that the aim to keep the national park nature untouched would fail without a restriction of Sámi rights within the parks. The aim of this thesis is to investigate how the distinction of nature from culture was renegotiated during the conflicts that preceded and followed this new stance. Tracing the impulses that fostered the reactions of the state administration back to their original contexts, complex interactions of differing interests are revealed. These contexts are examined in three case studies. The first case centers on nomad school superintendent Erik Bergström and his warning of the effects on the national parks from reindeer herders activities. The intersection of nature preservation and Sámi politics sheds light on their common outset in the use of the nature-culture dichotomy in approaching the Sámi. This contributes to explain the resistance by which the interest of change was met by those invested in the prevailing state policy towards the Sámi.The second case concerns a conflict of Sámi land use in the Abisko national park by the early 1930s. Several factors that possibly induced state officials to react on Sámi fishing and hunting in the national park are illuminated. These include different understanding of nature preservation, the moral ecology among the Sámi and antagonism between Sámi reindeer herders and inhabitants in the railway towns.The third case involves concerns raised in the process of establishing a new national park in the Muttos/Muddus area. A shift in focus from mountainous to forest landscapes among nature preservationists resulted in the inclusion of new stakeholders and fields of knowledge about land use and its effects. This seems to have spurred problematizing of both the ideal of pristine nature and of Sámi land use. A conflict was triggered by the in-migration of two reindeer herding families.In conclusion, it will be argued that it was a series of quite contextually different conflicts that interacted to undermine the institutionalized demarcation of nature. This simultaneously challenged Sámi rights in the national parks and took place in ideological opposition to the foundation of segregationist Sámi policy.

  • 18.
    Popescu, Cosmin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    CFRP Strengthening of Cut-Out Openings in Concrete Walls – Analysis and Laboratory Tests2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Redesigning buildings to improve their space efficiency and allow changes in use is often essential during their service lives to comply with shifts in living standards and functional demands.This may require the introduction of new openings in elements such as beams, walls, and slabs,which inevitably reduces their structural performance and hence requires repair or strengthening.However, there are uncertainties regarding both the effects of openings and the best remedial optionsfor them. Traditionally, two methods have been used to strengthen reinforced concrete (RC) walls with openings, these being either to create a frame around the opening using RC/steel membersor to increase the cross-sectional thickness. Currently, intervention in existing buildings must be minimal in order to minimise inconvenience caused by limiting the use of the structure during repairs. One option is to use externally-bonded fibre-reinforced polymers (FRPs).

    In this study, the author reports on an experimental investigation of the effectiveness of carbonFRP (CFRP)–based strengthening for restoring the axial capacity of a solid reinforced concretewall after cutting openings. Nine half-scale specimens, designed to represent typical wall panels in residential buildings with and without door-type openings, were tested to failure. The walls were tested in two-way action and subjected to axial loading with low eccentricity (defined as one sixth of the wall’s thickness) along the weak axis to represent imperfections due to thickness variation and misalignment of the panels during the construction process. An extensive instrumentation scheme was used to monitor the specimen’s behaviour during the loading cycles. In addition to classical approaches for measuring strains and displacements, optical 3D measurements were also acquired using the digital image correlation (DIC) technique. These provided better overviews of the failure mechanism by recording the crack pattern development and deformation of the walls throughout the loading history.

    Reducing the cross-sectional area by cutting out openings i.e. 25% (hereafter referred to as small opening) and 50% (hereafter referred to as large opening) led to 36% and 50% reductions in peak loads, respectively. In both situations the failure was brittle due to crushing of concrete with spalling and reinforcement buckling. The CFRP strengthening increased the axial capacity of walls with small and large openings by 34 – 50% and 13 – 27%, respectively. This partially restored theircapacities to 85 – 95% and 57 – 63% of their precutting capacity (i.e. solid wall), respectively. A procedure based on a rigid-plastic approach for evaluating the ultimate load of walls with cut-out openings that have been strengthened with FRPs was also proposed in this study. Predictions made using the proposed method agree closely with experimental results.

  • 19.
    Häggquist, Elisabeth
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Social Sciences.
    The interrelated use of geological information and other types of geoinformation in local governments2017In: Transactions on GIS, ISSN 1361-1682, E-ISSN 1467-9671Article in journal (Refereed)
    Abstract [en]

    There is a growing interest in the use of geoinformation in government decision-making. Studies on the usability of geological information, which is one type of geoinformation, have however been scarce in the literature. A system built for an efficient organization may, therefore, not be catering to the needs of the individual user and understanding the perceived barriers to using geological information should be an important goal of geodata implementation. The objectives of this article are to: (1) investigate whether the analyses of user patterns are improved by considering an interrelated estimation with two types of geoinformation, and (2) explore whether there are gender differences in how peer advice affects the use of geoinformation. The data were collected in 2014 through a web survey, and the sample consisted of 390 women and 287 men working in Swedish municipalities. The results indicates a more accurate prediction pattern when a secondary geoinformation decision was included, thus suggesting that different types of geoinformation should be jointly analyzed. The officials tend to use both types of geoinformation, alluding to a demand for combined geoinformation products among the target population. Finally, there is evidence of women's decision to use geoinformation being affected by peer advice

  • 20.
    Zhang, Qinhong
    et al.
    Sino-US Global Logistics Institute, Shanghai Jiao Tong University.
    Zhang, Dali
    Sino-US Global Logistics Institute, Shanghai Jiao Tong University.
    Segerstedt, Anders
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Luo, Jianwen
    School of Management, Shanghai Jiao Tong University.
    Optimal ordering and pricing decisions for a company issuing product-specific gift cards2017In: Omega, ISSN 0030-2228, E-ISSN 1541-3764Article in journal (Refereed)
    Abstract [en]

    In this paper, we investigate gift card's influence on retailers’ ordering decisions and analyse the benefits of issuing product-specific gift cards. We propose an optimal ordering model for retailers’ decision problems with gift cards being issued. We also solve the problem with the analytical forms of optimal order quantities and expected profits. By comparing the results with the classical newsvendor problem, we classify the benefits of issuing gift cards into three categories: (1) the demand stimulating; (2) the pre-payment, and (3) the non-redemption. We step further to explore a retailer's problem on how to determine the optimal discount for gift cards, which is characterized by a joint optimal policy on the ordering quantity and the discount. We derive the optimal condition on this joint policy. Numerical examples are conducted to illustrate the model results and analyse the influences of parameters. A sample average approximation method is also been introduced to solve the optimization model.

  • 21.
    Sarkar, Chiranjit
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Westerberg, Lars-Göran
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lundström, Staffan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Numerical simulations of lubricating grease flow in a rectangular channel with- and without restrictions2017In: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397XArticle in journal (Refereed)
    Abstract [en]

    This paper presents numerical simulations of the laminar flow of lubricating greases in a channel with rectangular cross section. Three greases with different consistencies (NLGI grades 00, 1 and 2 respectively) have been considered in three different configurations comprised by a rectangular channel without restrictions, one rectangular step restriction, and one double lip restriction. The driving pressure drop over the channel spans from 30 kPa to 250 kPa. The grease rheology is described by the Herschel-Bulkley rheology model, and both the numerical code and rheology model have been validated with analytical solutions and flow measurements using micro Particle Image Velocimetry.

  • 22.
    Zamani, Mohammadreza
    et al.
    Department of Materials and Manufacturing, School of Engineering, Jönköping University.
    Dini, Hoda
    Department of Materials and Manufacturing, School of Engineering, Jönköping University.
    Svoboda, Ales
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Lindgren, Lars-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Seifeddine, Salem
    Department of Materials and Manufacturing, School of Engineering, Jönköping University.
    Andersson, Nils-Eric
    Department of Materials and Manufacturing, School of Engineering, Jönköping University.
    Jarfors, Anders E.W.
    Department of Materials and Manufacturing, School of Engineering, Jönköping University.
    A dislocation density based constitutive model for as-cast Al-Si alloys: Effect of temperature and microstructure2017In: International Journal of Mechanical Sciences, ISSN 0020-7403, E-ISSN 1879-2162, Vol. 121, 164-170 p.Article in journal (Refereed)
    Abstract [en]

    The flow stress of an as-cast Al-Si based alloy was modeled using a dislocation density based model. The developed dislocation density-based constitutive model describes the flow curve of the alloy with various microstructures at quite wide temperature range. Experimental data in the form of stress-strain curves for different strain rates ranging from 10−4 to 10−1 s−1 and temperatures ranging from ambient temperature up to 400 °C were used for model calibration. In order to model precisely the hardening and recovery process at elevated temperature, the interaction between vacancies and dissolved Si was included. The calibrated temperature dependent parameters for different microstructure were correlated to the metallurgical event of the material and validated. For the first time, a dislocation density based model was successfully developed for Al-Si cast alloys. The findings of this work expanded the knowledge on short strain tensile deformation behaviour of these type of alloys at different temperature, which is a critical element for conducting a reliable microstructural FE-simulation.

  • 23.
    Grzenda, Maciej
    et al.
    Faculty of Mathematics and Information Science, Warsaw University of Technology,, Research and Development Center.
    Furtak, Janusz
    Military University of Technology, Warszawa.
    Legierski, Jarosław
    Faculty of Mathematics and Information Science, Warsaw University of Technology, Warszawa.
    Awad, Ali Ismail
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Network Architectures, Security, and Applications: An Introduction2017In: Advances in Network Systems: Architectures, Security, and Applications / [ed] Maciej Grzenda, Ali Ismail Awad, Janusz Furtak, Jarosław Legierski, Berlin: Springer Berlin/Heidelberg, 2017, 1-10 p.Chapter in book (Refereed)
    Abstract [en]

    Owing to the ever growing communication systems, modern networks currently encompass a wide range of solutions and technologies, including wireless and wired networks and provide basis for network systems from multiple partly overlapping domains such as the Internet of Things (IoT), cloud services, and network applications. This appears in numerous active research areas with particular attention paid to the architecture and security of network systems. In parallel, novel applications are developed, in some cases strongly linked to rapidly developing network-based data acquisition and processing frameworks. This chapter presents a general introduction to the topics of network architectures, security, and applications in addition to short descriptions of the chapters included in this volume

  • 24.
    Trivedi, Chirag
    et al.
    Waterpower Laboratory, Norwegian University of Science and Technology.
    Cervantes, Michel
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Fluid-structure interactions in Francis turbines: A perspective review2017In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 68, no 1, 87-101 p.Article in journal (Refereed)
    Abstract [en]

    Competitive electricity prices and reduced profit margins have forced hydraulic turbines to operate under critical conditions. The demand for extended operating ranges and the high efficiency of the turbine runners have forced manufacturers to produce lightweight runners. A turbine runner sometimes experiences resonance when a forced (flow-induced) excitation frequency approaches the runner’s natural frequency, resulting in failure. The cost of structural failure after commissioning is prohibitive. To attain a reliable and safe runner design, understanding of the structural response to flow-induced excitations is important. High amplitude pressure pulsations cause fatigue loading of the blades, which develop cracks over time. The amplitudes are dependent on the flow conditions, type of turbine and stator/rotor vane combinations. The structural response is dependent on the material properties, flow-induced damping and natural frequencies. Moreover, in a hydraulic turbine, changes in flow velocity from less than 1 m s−1 to over 40 m s−1 create challenges in predicting the response.

    The main objective of this article is to review the studies conducted on fluid-structure interactions within hydraulic turbines. Several aspects are reviewed, such as flow-induced excitation, added mass effect, hydrodynamic damping, and blade flutter. Both experimental and numerical studies are discussed in this article. This review also discusses the consequences of an increased number of transient cycles, such as load variation, start-stop and total load rejection, on the turbines and the fatigue loading. Finally, an attempt is made to highlight the important requirements for prospective fluid-structure analysis to fill current gaps in the literature.

  • 25.
    Zairov, Rustem
    et al.
    A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Mustafina, Asyia
    A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Shamsutdinova, Nataliya
    A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Nizameev, Irek
    A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Moreira, Beatriz
    Department of Chemistry and Molecular Biology, University of Gothenburg.
    Sudakova, Svetlana
    A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Podyachev, Sergey
    A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Fattakhova, Alfia
    Kazan (Volga region) Federal university.
    Safina, Gulnara
    Department of Chemistry and Molecular Biology, University of Gothenburg.
    Lundström, Ingemar
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Gubaidullin, Aidar
    A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    High performance magneto-fluorescent nanoparticles assembled from terbium and gadolinium 1,3-diketones2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, 40486Article in journal (Refereed)
    Abstract [en]

    Polyelectrolyte-coated nanoparticles consisting of terbium and gadolinium complexes with calix[4]arene tetra-diketone ligand were first synthesized. The antenna effect of the ligand on Tb(III) green luminescence and the presence of water molecules in the coordination sphere of Gd(III) bring strong luminescent and magnetic performance to the core-shell nanoparticles. The size and the core-shell morphology of the colloids were studied using transmission electron microscopy and dynamic light scattering. The correlation between photophysical and magnetic properties of the nanoparticles and their core composition was highlighted. The core composition was optimized for the longitudinal relaxivity to be greater than that of the commercial magnetic resonance imaging (MRI) contrast agents together with high level of Tb(III)-centered luminescence. The tuning of both magnetic and luminescent output of nanoparticles is obtained via the simple variation of lanthanide chelates concentrations in the initial synthetic solution. The exposure of the pheochromocytoma 12 (PC 12) tumor cells and periphery human blood lymphocytes to nanoparticles results in negligible effect on cell viability, decreased platelet aggregation and bright coloring, indicating the nanoparticles as promising candidates for dual magneto-fluorescent bioimaging

  • 26.
    Alfieri, Luisa
    et al.
    Department of Engineering, University of Naples Parthenope, Centro Direzionale of Naples.
    Bracale, Antonio
    Department of Engineering, University of Naples Parthenope, Centro Direzionale of Naples.
    Carpinelli, Guido
    Department of Electrical Engineering and Information Technology, University of Naples Federico II.
    Larsson, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    A Wavelet-Modified ESPRIT Hybrid Method for Assessment of Spectral Components from 0 to 150 kHz2017In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, no 1, 97Article in journal (Refereed)
    Abstract [en]

    Waveform distortions are an important issue in distribution systems. In particular, the assessment of very wide spectra, that include also components in the 2-150 kHz range, has recently become an issue of great interest. This is due to the increasing presence of high-spectral emission devices like end-user devices and distributed generation systems. This study proposed a new sliding-window wavelet-modified estimation of signal parameters by rotational invariance technique (ESPRIT) method, particularly suitable for the spectral analysis of waveforms that have very wide spectra. The method is very accurate and requires reduced computational effort. It can be applied successfully to detect spectral components in the range of 0-150 kHz introduced both by distributed power plants, such as wind and photovoltaic generation systems, and by end-user equipment connected to grids through static converters, such as fluorescent lamps.

  • 27.
    Näslund, Rebecka
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    “The World at Your Fingertips if You Know the Computer”: Agency, Information and Communication Technologies and Disability2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis focuses on the relationships between agency, Information and Communication Technologies (ICT) and people with disability (in various ages). The aim has been to create an understanding by describing and analysing, and as such, to develop knowledge of how people with disabilities experience agency, ICT, and disability in their everyday lives. The frame of reference is inspired by disability studies, feminist studies and science and technologies studies (STS). The empirical material was collected in, Norrbotten (Sweden’s northernmost region) and Muscat (the capital area of the Sultanate of Oman) by an autobiographical account, audio-visual material, drawings, interviews, observations, and reading of textual documents. The thesis consists of six papers. The main findings outline that agency, ICT, disability, and gender are part of intra-actions between material entities (such as bodies, technologies, etc.) and practices. The thesis also explores that disability in Sweden and Oman are understood in a variety of ways. Additionally, it presents that the combination of the notions of interference with situated knowledges can contribute with alternative methodological insights about the interference of disability, gender, ICT, the participants’ and researchers’ experiences and understandings to make accountable knowledge claims. Moreover, the thesis presents that material entities (bodies and technologies) and practices are part of different modes of ordering disability which bear effects on the lives of people with disabilities. It additionally disentangles that materialities such as the Internet intra-act with other material entities (for instance, bodies) and practices which enact various forms of agency which bear effects on the everyday lives of people with disability and their ways to participate. Finally, the thesis outlines some implications that an intra-acting understanding of the use of Internet can contribute with in research which focuses on disability, participation, and agency.

  • 28.
    Edvardsson, David
    et al.
    The Medical Faculty, Department of Nursing, Umeå University, .
    Sjögren, Karin
    The Medical Faculty, Department of Nursing, Umeå University, .
    Lood, Qarin
    The Medical Faculty, Department of Nursing, Umeå University, .
    Bergland, Ådel
    Department of Nursing Science, Faculty of Medicine, Institute of Health and Society, University of Oslo .
    Kirkevold, Marit
    Department of Nursing Science, Faculty of Medicine, Institute of Health and Society, University of Oslo.
    Sandman, Per-Olof
    Luleå University of Technology, Department of Health Sciences, Nursing Care.
    A person-centred and thriving-promoting intervention in nursing homes: study protocol for the U-Age nursing home multi-centre, non-equivalent controlled group before-after trial2017In: BMC Geriatrics, ISSN 1471-2318, E-ISSN 1471-2318, Vol. 17, 22Article in journal (Refereed)
    Abstract [en]

    Background

    The literature suggests that person-centred care can contribute to quality of life and wellbeing of nursing home residents, relatives and staff. However, there is sparse research evidence on how person-centred care can be operationalised and implemented in practice, and the extent to which it may promote wellbeing and satisfaction. Therefore, the U-Age nursing home study was initiated to deepen the understanding of how to integrate person-centred care into daily practice and to explore the effects and meanings of this.

    Methods

    The study aims to evaluate effects and meanings of a person-centred and thriving-promoting intervention in nursing homes through a multi-centre, non-equivalent controlled group before-after trial design. Three nursing homes across three international sites have been allocated to a person-centred and thriving-promoting intervention group, and three nursing homes have been allocated to an inert control group. Staff at intervention sites will participate in a 12-month interactive educational programme that operationalises thriving-promoting and person-centred care three dimensions: 1) Doing a little extra, 2) Developing a caring environment, and 3) Assessing and meeting highly prioritised psychosocial needs. A pedagogical framework will guide the intervention. The primary study endpoints are; residents’ thriving, relatives’ satisfaction with care and staff job satisfaction. Secondary endpoints are; resident, relative and staff experiences of the caring environment, relatives’ experience of visiting their relative and the nursing home, as well as staff stress of conscience and perceived person-centredness of care. Data on study endpoints will be collected pre-intervention, post-intervention, and at a six-month follow up. Interviews will be conducted with relatives and staff to explore experiences and meanings of the intervention.

    Discussion

    The study is expected to provide evidence that can inform further research, policy and practice development on if and how person-centred care may improve wellbeing, thriving and satisfaction for people who reside in, visit or work in nursing homes. The combination of quantitative and qualitative data will illuminate the operationalisation, effects and meaning of person-centred and thriving-promoting care.

  • 29.
    Zainy, Maher T.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Al-Ansari, Nadhir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Bauer, Tobias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    The Tectonic and Structural Classifications of the Western Part of the Zagros Fold and Thrust Belt, North Iraq, Review and Discussion2017In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 7, no 2, 71-89 p.Article in journal (Refereed)
    Abstract [en]

    The Zagros fold and thrust belt represents a tectonically significant area, and one of the richest areas in oil and gas reservoirs in the world. The Zagros fold and thrust belt is the deformational product of the Cretaceous-present day convergence of the Arabian and Iranian (Eurasian) plates (subduction and collision). The belt extends more than 2000 km from southern Turkey through the north and northeastern Iraq to the Strait of Hormuz in southwestern Iran. The Zagros fold and thrust belt is divided into two parts which are; Western part within Iraqi region and Eastern part within Iranian region. The western part of the Zagros fold and thrust belt has been traditionally subdivided into several structural zones that are generally striking parallel to the plate boundary. This is characterized by exposure of Late Ordovician to Pliocene - Pliestocene formations with different types of Quaternary Sediments. This research will concentrate on Western part of Zagros fold and thrust belt and the styles of structural classifications, which will aid to clarify and better understand the tectonic and structural history and evolution of the region. We have considered the last version of structural classification as the most relevant one to the reality, especially within outer platform (Unstable shelf). Where it divides the region into four structural zones, which are: Low Folded zone, High Folded Zone, Imbricate Zone, and Zagros Suture Zone and these zones were further divided to several subzones. This classification is based on the structural style and intensity of deformation, stratigraphy, mechanicalstratigraphy and tectono-stratigraphy of the deformed sequences, Age of deformation, surface physiography and morphology. The data used in the classification is more reliable, up to date and relevant.

  • 30.
    Hansson, Johan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Moderna Fysiken på 15 Minuter2017Book (Other (popular science, discussion, etc.))
  • 31.
    Gerdes, Mike
    et al.
    Department of Automotive and Aeronautical Engineering, HAW Hamburg.
    Galar, Diego
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Scholz, Dieter
    Hamburg University of Applied Sciences, Aero - Aircraft Design and Systems Group.
    Decision trees and the effects of feature extraction parameters for robust sensor network design2017In: Eksploatacja i Niezawodnosc - Maintenance and Reliability, ISSN 1507-2711, Vol. 19, no 1, 31-42 p.Article in journal (Refereed)
    Abstract [en]

    Reliable sensors and information are required for reliable condition monitoring. Complex systems are commonly monitored by many sensors for health assessment and operation purposes. When one of the sensors fails, the current state of the system cannot be calculated in same reliable way or the information about the current state will not be complete. Condition monitoring can still be used with an incomplete state, but the results may not represent the true condition of the system. This is especially true if the failed sensor monitors an important system parameter. There are two possibilities to handle sensor failure. One is to make the monitoring more complex by enabling it to work better with incomplete data; the other is to introduce hard or software redundancy. Sensor reliability is a critical part of a system. Not all sensors can be made redundant because of space, cost or environmental constraints. Sensors delivering significant information about the system state need to be redundant, but an error of less important sensors is acceptable. This paper shows how to calculate the significance of the information that a sensor gives about a system by using signal processing and decision trees. It also shows how signal processing parameters influence the classification rate of a decision tree and, thus, the information. Decision trees are used to calculate and order the features based on the information gain of each feature. During the method validation, they are used for failure classification to show the influence of different features on the classification performance. The paper concludes by analysing the results of experiments showing how the method can classify different errors with a 75% probability and how different feature extraction options influence the information gain

  • 32.
    Moretti, Elisa
    et al.
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, INSTM Venice Research Unit.
    Pizzol, Giorgia
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, INSTM Venice Research Unit.
    Fantin, Marina
    Nanofab-Veneto Nanotech, Marghera (Venice).
    Enrichi, Francesco
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Scopece, Paolo
    Nanofab-Veneto Nanotech, Marghera (Venice).
    Ocaña, Manuel
    Instituto de Ciencia de Materiales de Sevilla, CSIC, .
    Polizzi, Stefano
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, INSTM Venice Research Unit.
    Luminescent Eu-doped GdVO4 nanocrystals as optical markers for anti-counterfeiting purposes2017In: Chemical Papers, ISSN 0366-6352, Vol. 71, no 1, 149-159 p.Article in journal (Refereed)
    Abstract [en]

    Luminescent Eu:GdVO4 nanoparticles, with an average size of 60 nm, were deposited first on monocrystalline silicon wafers, then on four different natural stone materials, by a spray-coating technique and a silica layer was subsequently deposited by atmospheric pressure plasma jet to protect the luminescent layer and improve its adhesion to the substrate. The luminescent films were characterized by photoluminescence excitation and emission, while the surface morphology was examined by FEG-SEM microscopy and spectroscopic ellipsometry to determine the coating thickness. The optical appearance of the coatings was also evaluated by colorimetric measurements and the efficacy of the fixing action of the silica layer was estimated by PL measurements performed before and after a Scotch™ tape peeling test. The proposed methodology, easily applied on the surface of stone supports, has led to the realization of a luminescent film displaying good mechanical properties, transparent and undetectable in the presence of visible light, but easily activated by UV light source, indicating that the Eu:GdVO4 nanophosphors could be used as luminescent nanotags for a reliable anti-counterfeiting technology.

  • 33.
    Bucur, Diana Maria
    et al.
    University POLITEHNICA of Bucharest.
    Cervantes, Michel
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Dunca, Georgiana
    University POLITEHNICA of Bucharest.
    Maximum pressure evaluation during expulsion of entrapped air from pressurized pipelines2017In: Journal of Applied Fluid Mechanics, ISSN 1735-3572, E-ISSN 1735-3645, Vol. 10, no 1, 11-20 p.Article in journal (Refereed)
    Abstract [en]

    Pressurized pipeline systems may have a wide operating regime. This paper presents the experimental analysis of the transient flow in a horizontal pipe containing an air pocket, which allows the ventilation of the air after the pressurization of the hydraulic system, through an orifice placed at the downstream end. The measurements are made on a laboratory set-up, for different supply pressures and various geometries of water column length, air pocket and expulsion orifice diameter. Dimensional analysis is carried out in order to determine a relation between the parameters influencing the maximum pressure value. A two equations model is obtained and a criterion is established for their use. The equations are validated with experimental data from the present laboratory set-up and with other data available in the literature. The results presented as nondimensional quantities variations show a good agreement with the previous experimental and analytical researches.

  • 34.
    Abdullah, Twana
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Groundwater Vulnerability Using DRASTIC model Applied to Halabja Saidsadiq Basin, IRAQ: 2017Licentiate thesis, comprehensive summary (Other academic)
  • 35.
    Stenström, Christer
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Nyckeltal för driftsäkerhet inom järnvägstransport2017Report (Other academic)
    Abstract [sv]

    Driftsäkra järnvägar och tåg är avgörande för konkurrenskraftig och ökande andel järnvägstranport. För uppföljning av driftsäkerhet använder infrastrukturförvaltare (Trafikverket), tågoperatörer och entreprenörer olika indikatorer, så som merförsening och antal funktionsfel. Indikatorerna mäter olika aspekter och kan illustreras mer eller mindre intuitivt och tilltalande. Metod för definiering och införsel av indikatorer skiljer sig mellan organisationer. En enkel och vanlig metod är diskussion och beslut inom en sammanträdande grupp. En mer objektiv metod är att följa uppsatta riktlinjer för definiering och utvärdering av indikatorer. Dock är det få allmängiltiga metoder tillgängliga för att definiera indikatorer. Utifrån behov inom järnvägstransport och avsaknaden av metoder för definiering och utvärdering av indikatorer, avses i denna studie en sådan allmänt tillämplig metod presenteras och appliceras inom järnvägstransport. Applicering innebär att i detalj dokumentera två indikatorer som kan användas som branschgemensamma nyckeltal inom järnvägstransport.

    Två indikatorer definierades och utvärderade i denna studie avseende möjlighet att tillämpa dessa som branschgemensamma indikatorer inom järnvägstransport. Val av indikatorer utgick från litteraturstudie av i Sverige gällande standarder avseende driftsäkerhet. Definiering och utvärdering av valda indikatorer utgick från mall av Neely (2002) bestående av 46 frågor.

    De definierade och utvärderade indikatorerna är tillgänglighet och feleffektmatris. Definiering och utvärdering av de två indikatorerna, med utgång från givna 46 frågor, tog i denna rapport fyra arbetsdagar (16 timmar/nyckeltal). Detta ger en fingervisning på arbetsinsatsen som krävs för en organisation som vill införa föreslagen metod för att definiera indikatorer. Förutsatt att data och ett underhållssystem finns tillgängligt, består kostnaderna vid implementering och drift i stora drag av: definiering och utvärdering; implementering av kod i underhållssystem; förbättringsarbete av indikatorer och kod; samt drift av kod i underhållssystem. Det kan därmed vara relevant att utföra en kostnad-nytta-analys avseende indikatorerna. En stor kostnad i sammanhanget är insamling av data. Dock ska denna kostnad eventuellt inte tillskrivas till indikatorerna, eftersom det troligtvis inte är acceptabelt att inte samla in data avseende antal fel, återställelsetider och merförseningar.

    Tre överväganden berörande indikatorn tillgänglighet som bör tas i beaktning är: möjlighet att bryta ner indikatorn för att komma närmare orsakerna till indikatorvärden; tidsrymd för beräkning; samt användande av median, medelvärde och registrerade återställningstider vid beräkning. Valen som görs vid en mjukvaruimplementering kan uppdateras efterhand med erfarenhet från tillämpning.

    En egenskap hos feleffektmatrisen, så som den är tillämpad i denna studie, är att den påverkas av tidtabeller och gångtidstillägg. Tillgänglighet påverkas inte av tidtabeller och gångtidstillägg, men kan istället inte fånga upp skillnaden mellan få långa fel och många korta fel, så som feleffektmatrisen gör. I detta avseende kompletterar tillgänglighet och feleffektmatris varandra.

  • 36.
    Zerva, Anastasia
    et al.
    Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens .
    Papaspyridi, Lefki Maria
    Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens .
    Christakopoulos, Paul
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Topakas, Evangelos
    National Technical University of Athens, School of Chemical Engineering, National Technical University of Athens, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens.
    Valorization of Olive Mill Wastewater for the Production of β-glucans from Selected Basidiomycetes2017In: Waste and Biomass Valorization, ISSN 1877-2641, E-ISSN 1877-265XArticle in journal (Refereed)
    Abstract [en]

    Purpose

    The aim of the present study was to investigate the feasibility of polysaccharides production by selected basidiomycetes in submerged culture. Olive mill wastewater (OMWW) was also tested as a potential substrate for polysaccharides production by mushroom strains, focusing on the simultaneous degradation and valorization of the waste material.

    Methods

    The tested strains were grown in two different substrates, and after biomass harvesting, polysaccharides were isolated using two different methods. The extracellular polysaccharides were isolated from the culture broth, with ethanol precipitation. The isolated fractions were partially characterized with FT-IR spectroscopy.

    Results

    All three strains performed well in both substrates. Maximum degradation performance of OMWW was achieved by Ganoderma lucidum, achieving 19.4% phenols reduction together with 47.56% decolorization. The extracellular polysaccharides (EPS) produced by all strains were found to be richer in total glucans during growth in semi-synthetic medium, compared to growth in OMWW-based medium. In regard to biomass polysaccharides, Pleurotus ostreatus biomass was found to be richer in glucans, reaching 8.68% (w/w) total glucan content when grown in semi-synthetic medium and 7.58% (w/w) when grown in OMWW-based medium. After purification of biomass polysaccharides with two methods, the fraction with the highest glucan content was found to be the one from G. lucidum after growth in semi-synthetic medium cultures, with 49.1% (w/w) total glucans. FT-IR spectra of the isolated samples revealed the bands corresponding to α- and β-glucosidic bonds, but also the existence of protein contamination.

    Conclusions

    Purification of biomass polysaccharides with two distinct methods revealed that α-amylase and Sevag treatments failed to remove completely α-glucans and proteins respectively, leading to the suggestion that these two steps could be omitted without significant impact. Moreover, the results imply that the valorization of OMWW might be feasible with the use of mushroom strains, leading to the production of important products, such as glucans.

  • 37.
    Wright, E.
    et al.
    Department of Physics and I3N, University of Aveiro, Campus Santiago.
    Coutinho, J.
    Department of Physics and I3N, University of Aveiro, Campus Santiago.
    Öberg, Sven
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Torres, V.J.B.
    Department of Physics and I3N, University of Aveiro, Campus Santiago.
    A first-principles model of copper-boron interactions in Si: for the light-induced degradation of solar Si2017In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 29, no 6, 065701Article in journal (Refereed)
    Abstract [en]

    The recent discovery that Cu contamination of Si combined with light exposure has a significant detrimental impact on carrier life-time has drawn much concern within the solar-Si community. The effect, known as the copper-related light-induced degradation (Cu-LID) of Si solar cells, has been connected to the release of Cu interstitials within the bulk (2016 Sol. Energy Mater. Sol. Cells 147 115-26). In this paper, we describe a comprehensive analysis of the formation/dissociation process of the CuB pair in Si by means of first-principles modelling, as well as the interaction of CuB defects with photo-excited minority carriers. We confirm that the long-range interaction between the Cu-i(+) cation and the B-s(-) anion has a Coulomb-like behaviour, in line with the trapping-limited diffusivity of Cu observed by transient ion drift measurements. On the other hand, the short-range interaction between the d-electrons of Cu and the excess of negative charge on B-s(-) produces a repulsive effect, thereby decreasing the binding energy of the pair when compared to the ideal point-charge Coulomb model. We also find that metastable CuB pairs produce acceptor states just below the conduction band minimum, which arise from the Cu level emptied by the B acceptor. Based on these results, we argue that photo-generated minority carriers trapped by the metastable pairs can switch off the Coulomb interaction that holds the pairs together, enhancing the release of Cu interstitials, and acting as a catalyst for Cu-LID.

  • 38.
    Gustafson, Anna
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Paraszczak, Jacek
    bDepartment of Mining, Metallurgical and Materials Engineering, Université Laval, Quebec City.
    Tuleau, Jocelyn
    bDepartment of Mining, Metallurgical and Materials Engineering, Université Laval, Quebec City.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Impact of technical and operational factors on effectiveness of automatic load-haul-dump machines2017In: Mining Technology, ISSN 1474-9009, E-ISSN 1743-2863Article in journal (Refereed)
    Abstract [en]

    The use of automatic load-haul-dump (LHD) machines in underground metal mines is a promising way to overcome some of the challenges now facing mining companies. They offer several potential benefits over man-operated units, mostly in terms of safety and health of the workers, but also in terms of higher availability, increased productivity, and reduced mining cost. That said, using such systems at their full capacity is a challenging and complex task. In this context, after describing some commercially available equipment and systems, the paper examines factors affecting reliability, availability and productivity of automatic LHDs and notes several technical and operational concerns.

  • 39.
    Pérez-Ràfols, Francesc
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Larsson, Roland
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    van Riet, Egbert J.
    Shell Global Solutions International BV, Innovation, Research and Development.
    Almqvist, Andreas
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    On the flow through plastically deformed surfaces under unloading: A spectral approach2017In: Proceedings of the Institution of mechanical engineers. Part C, journal of mechanical engineering science, ISSN 0954-4062, E-ISSN 2041-2983Article in journal (Refereed)
    Abstract [en]

    This study considers flow through the gap left between two surfaces during unloading, in other words, when an applied load is gradually reduced after loading to a state where plastic deformation occurs. In particular, the permeability of the gap is studied. It was found that a substantial reduction of the applied load is required before the permeability starts to increase significantly. The explanation for this phenomenon is given by the combination of components with different wavelengths present in the surface. Components with long wavelengths deform elastically and those with shorter wavelengths may also deform plastically. We found that plastic deformation acts to keep the permeability nearly constant at the beginning of the unloading and elastic spring-back is responsible for the rapid increase at lower loads. This principle constitutes a basis for the strategy that was developed in order to predict the load at which the rapid increase of permeability starts.

  • 40.
    Schnabel, Stephan
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Golling, Stefan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.
    Marklund, Pär
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Larsson, Roland
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    The influence of contact time and event frequency on acoustic emission signals2017In: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305XArticle in journal (Refereed)
    Abstract [en]

    Studies of acoustic emissions (AE) of rotating machine elements is often performed under a constant speed. There are few investigations on speed and contact time dependency of acoustic emission signals, even though some investigations have reported difficulties at elevated rotational speeds. Simplified experiments are, therefore, presented in this article to increase the understanding of the time dependency of acoustic emission signals. Hertzian impacts and tensile tests are used to study contact time, the time duration of an event and offset time, the time between events and accordingly the event frequency. The results of these model experiments indicate an indirect quadratic proportionality of acoustic emission amplitudes and contact time (umax∝1/(tc2)">u max ∝1/(t 2 c ) umax∝1/(tc2) ), as well as a proportional relationship between the root mean square and event frequency (RMS∝fevent∝1/toffset">RMS∝f event ∝1/t offset  RMS∝fevent∝1/toffset ). The relationship between contact time and the root mean square of acoustic emission signals is strongly dependent on the damping of the system

  • 41.
    Scheepers, Gerhard
    et al.
    RISE Bioekonomi.
    Olsson, Jörgen
    RISE Bioekonomi.
    Lycken, Anders
    RISE Bioekonomi.
    Grahn, Thomas
    RISE Bioekonomi.
    Lundqvist, Sven-Olof
    RISE Bioekonomi.
    Hagman, Olle
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Hållfasthetsbestämning av virke med en NIR-kamera2017Report (Other academic)
  • 42.
    Cervantes, Michel
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Trivedi, Chirag
    Norwegian University of Science and Technology (NTNU), Trondheim.
    Dahlhaug, Ole Gunnar
    Department of Energy and Process Engineering, Water Power Laboratory, Norwegian University of Science and Technology, Trondheim, Norwegian University of Science and Technology (NTNU), Trondheim.
    Nielsen, Torbjørn Kristian
    Norwegian University of Science and Technology (NTNU), Trondheim.
    Francis-99 Workshop 2: transient operation of Francis turbines2017In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 782, 11001Article in journal (Other academic)
  • 43.
    Samuelsson, Björn
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Arbetsskador i byggverksamhet 2015: Privat och offentlig verksamhet : bygg- och anläggning, byggnadsplåtslageri, elinstallation, ventilation, VVS, måleri, Glasmästeri, maskinentreprenad2017Report (Other academic)
  • 44.
    Linjamaa, Aki
    et al.
    Department of Materials Science, Tampere University of Technology.
    Lehtovaara, Arto
    Department of Materials Science, Tampere University of Technology.
    Larsson, Roland
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Kallio, Marke
    Research & Development, Metso Minerals Oy.
    Söchting, Sven
    Materials & Tribology, Component Expertise, Engines R&D, Wärtsilä .
    Modelling and Analysis of Elastic and Thermal Deformations of a Hybrid Journal Bearing2017In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464Article in journal (Refereed)
    Abstract [en]

    The continuous demand for higher power density leads to a very challenging operational environment for sliding bearings regarding pressures and deformations. Understanding of the deformation behavior of heavily loaded bearings becomes even more pronounced when modern hybrid multilayer designs are considered. The aim of this study is to develop a numerical, multi-physical model for the evaluation of journal bearing performance. Hydrodynamics were based on the Reynolds equation and deformations were calculated using the integrated finite element method. Elastic and thermal deformations have a significant effect on bearing performance and those deformations can be adjusted with properties of polymer layer. The design of hybrid bearings is delicate and their properties must be tailored according to the operating conditions

  • 45.
    Johansson, Charlotta
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Lindelöw, David
    Sweco.
    Rosander, Peter
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
    Förstudie: Effekter av att satsa på transportslaget gång2017Report (Other academic)
  • 46.
    Capaci, Francesca
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Bergquist, Bjarne
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Kulahci, Murat
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Vanhatalo, Erik
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Exploring the Use of Design of Experiments in Industrial Processes Operating Under Closed-Loop Control2017In: Quality and Reliability Engineering International, ISSN 0748-8017, E-ISSN 1099-1638Article in journal (Refereed)
    Abstract [en]

    Industrial manufacturing processes often operate under closed-loop control, where automation aims to keep important process variables at their set-points. In process industries such as pulp, paper, chemical and steel plants, it is often hard to find production processes operating in open loop. Instead, closed-loop control systems will actively attempt to minimize the impact of process disturbances. However, we argue that an implicit assumption in most experimental investigations is that the studied system is open loop, allowing the experimental factors to freely affect the important system responses. This scenario is typically not found in process industries. The purpose of this article is therefore to explore issues of experimental design and analysis in processes operating under closed-loop control and to illustrate how Design of Experiments can help in improving and optimizing such processes. The Tennessee Eastman challenge process simulator is used as a test-bed to highlight two experimental scenarios. The first scenario explores the impact of experimental factors that may be considered as disturbances in the closed-loop system. The second scenario exemplifies a screening design using the set-points of controllers as experimental factors. We provide examples of how to analyze the two scenarios

  • 47.
    Kokkola, Lydia
    et al.
    Luleå University of Technology, Department of Arts, Communication and Education, Education, Language, and Teaching.
    Valovirta, Elina
    The University of Turku.
    The Disgust that Fascinates: Sibling Incest as a Bad Romance2017In: Sexuality & Culture, ISSN 1095-5143, E-ISSN 1936-4822, Vol. 21, no 1, 121-141 p.Article in journal (Refereed)
    Abstract [en]

    This article compares the discourse of sibling incest evident in a corpus offiction with the discourse found in clinical, sociological and criminal literature.Whereas the former prima rily regards the coupling as a bad romance, the latterpresents the idea that it is unequivocally harmful. This discrepancy between the twodiscourses surrounding sexual relationships between brothers and sisters speaks toliterary fiction’s need for thwarted romances for the purposes of the literary market.A more detailed look into three novels from the corpus, Tabitha Suzuma’s For-bidden (2010), Donna Tartt’s The Secret History (1992) and Pauline Melville’s TheVentriloquist’s Tale (1997) shows how this logic of sibling incest as a bad romanceworks in practice.

  • 48.
    Häggström, Jens
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Bridge over Åby River: Evaluation of full scale testing2017Report (Other academic)
  • 49.
    Zhang, Yang
    et al.
    Resilience Engineering Research Group, University of Nottingham.
    Andrews, John
    Resilience Engineering Research Group, University of Nottingham.
    Reed, Sean
    Resilience Engineering Research Group, University of Nottingham.
    Karlberg, Magnus
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Maintenance Processes Modelling and Optimisation2017In: Reliability Engineering & System Safety, ISSN 0951-8320, E-ISSN 1879-0836Article in journal (Refereed)
    Abstract [en]

    A Maintenance Procedure is conducted in order to prevent the failure of a system or to restore the functionality of a failed system. Such a procedure consists of a series of tasks, each of which has a distribution of times to complete and a probability of being performed incorrectly. The inclusion of tests can be used to identify any maintenance errors which have occurred. When an error is identified it can be addressed through a corresponding correction sequence which will have associated costs and add to the maintenance process completion time. A modified FMEA approach has been used to identify the possible tests. By incorporating any selection of tests into the maintenance process it can then analysed using a discrete-event simulation to predict the expected completion time distribution. The choice of tests to perform and when to do them is then made to successfully complete the maintenance objective in the shortest possible time using a genetic algorithm. The methodology is demonstrated by applying it to the repair process for a car braking system. The developed method is suitable for application in abroad range of industries.

  • 50.
    Näslund, Rebecka
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Al Said, Shariffa Khalid Qais
    Ministry of Education, Sultanate of Oman.
    Modes of ordering disability: students living with visual disabilities in the Sultanate of Oman2017In: Scandinavian Journal of Disability Research, ISSN 1501-7419, E-ISSN 1745-3011, Vol. 19, no 2, 79-90 p.Article in journal (Refereed)
    Abstract [en]

    This article examines how a group of students with visual disabilities speak about becoming disabled and living with disability in relation to: material entities, practices, and their own expectations regarding the future in the Sultanate of Oman. It draws upon individual interviews among six adults with visual disabilities. The article outlines, from a material semiotics approach, how various forms of modes of ordering enact disability. An interdisciplinary approach, informed by disability studies and science and technology studies, is implemented to interpret: How do students with visual disabilities express the relationships between material entities (such as bodies and technologies) and practices? In what ways are these relationships enacting different modes of ordering disability? What kind of modes of ordering disability are the participants experiencing in their lives? How have they responded to the modes of ordering that they have encountered?

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