Luleå University of Technology Publications
Not a member yet
39356 research outputs found
Sort by
Recycling or Sustainability: The Road of Electric Vehicles Toward Sustainable Economy via Blockchain
No full textThis semi-systematic review paper discusses four research questions based on findings from the last 10 years: What are the crucial issues in the ongoing debate on the development of the electric vehicle (EV) concept? Where are the major conflicting points and focuses between sustainable economy and EVs? How does the mining of metals and minerals follow current zero-waste sustainability trends, and how does the prediction of the magnitude of the future demand for EV batteries guide strategic decision-making in policies throughout the globe? As it is not easy to currently predict how metals necessary for EV productions will be produced, this article suggests a strategy that is diverse regarding its approaches to shaping the sustainable mining and further development of EVs, along with the involvement of urban planning. Using broad literature and a published pool of prediction scenarios, we provide a comprehensive assessment of future EV battery raw materials development under a range of scenarios, accounting for factors such as developments in battery technology, variations in the EV fleet composition, sustainability aspects of development of second use and recycling technologies. Additionally, this paper demonstrates how blockchain technology is likely to force mineral and metal supply chains to become significantly more traceable and transparent.Validerad;2025;Nivå 1;2025-05-09 (u8);Funder: Ministry of Education, Science and Technological Development of the Republic of Serbia (451-03-136/2025-03/20005);Full text license: CC BY</p
Roadmap on metamaterial theory, modelling and design
No full textThis Roadmap surveys the diversity of different approaches for characterising, modelling and designing metamaterials. It contains articles covering the wide range of physical settings in which metamaterials have been realised, from acoustics and electromagnetics to water waves and mechanical systems. In doing so, we highlight synergies between the many different physical domains and identify commonality between the main challenges. The articles also survey a variety of different strategies and philosophies, from analytic methods such as classical homogenisation to numerical optimisation and data-driven approaches. We highlight how the challenging and many-degree-of-freedom nature of metamaterial design problems call for techniques to be used in partnership, such that physical modelling and intuition can be combined with the computational might of modern optimisation and machine learning to facilitate future breakthroughs in the field.Validerad;2025;Nivå 2;2025-05-15 (u8);Full text license: CC BY</p
Postcolonial Perspectives on Swedish Development Aid Policy : A Discourse Analysis of "Aid for a New Era"
No full textStudien analyserar Sveriges samtida biståndspolitik genom en kritisk diskursanalys av strategidokumentet Bistånd för en ny era. Med stöd i postkolonial teori och Norman Faircloughs tredimensionella modell för kritisk diskursanalys analyseras hur språkliga konstruktioner i dokumentet reproducerar eller utmanar koloniala maktrelationer. Resultatet visar att biståndsdiskursen domineras av ett teknokratiskt och marknadsekonomiskt språkbruk, vilket positionerar Sverige som en aktiv och rationell aktör medan mottagarländer framställs som passiva och beroende. Samtidigt görs försök att omformulera diskursen i mer partnerskapsorienterade termer genom betoning på lokal kapacitetsutveckling och mottagarländers ansvar. Trots de uttalade ambitionerna sker detta inom ramen för en fortsatt hierarkisk asymmetrisk utvecklingslogik, vilket begränsar dess genomslag. Studien pekar på att biståndet snarare fungerar som ett utrikespolitiskt verktyg för nationella intressen än ett uttryck för global solidaritet, vilket reproducerar asymmetriska relationer och diskursiv makt inom den globala ordningen.This thesis explores Sweden´s contemporary development aid policy through a critical discourse analysis of the strategic document Bistånd för en ny era (Aid for a New Era). Employing postcolonial theory and Norman Fairclough´s three-dimensional model of critical discourse analysis, the study investigates how linguistic constructions within the policy document reproduce or challenge colonial power dynamics. The findings reveal that the aid discourse is dominated by a technocratic and market-oriented language, positioning Sweden as an active and rational actor while recipient countries are portrayed as passive and dependent. At the same time, efforts are made to reframe the discourse in more partnership-oriented terms, emphasizing local capacity-building and recipient country responsibility. However, these ambitions operate within the framework of a persistent hierarchical and asymmetrical development logic, limiting their impact. The study concludes that aid functions primarily as a foreign policy instrument serving national interests rather than a genuine expression of global solidarity, thereby reproducing asymmetrical relations and epistemic violence within the international order.
Moas skattkista scattar bäst som scattar sist : Ett arbete om jazzens improvisation och scatvokabulär
No full textI det här examensarbetet utforskar jag vokabulär inom scatsång för att, om möjligt, tydliggöramitt eget improvisatoriska uttryck och identifiera mina individuella utmaningar.Utgångspunkten var en nyfikenhet på hur skickliga jazzvokalister utformar sinaimprovisationer och vilka ljud som skapar deras musikaliska språk.Syftet var att genom analys och praktik utveckla en större mångsidighet som improviserandesångare med fokus på min scatvokabulär. Det musikaliska materialet bestod avimprovisationer från sex stilistiskt olika jazzvokalister, valda för att representera variationinom genren.Processen byggde på att transkribera, analysera och härma vokalisterna. Vissa metoder,såsom att transkribera solon, visade sig vara särskilt givande, medan andra, som att imiteravissa vokalister, var mindre effektiva.Resultatet blev en ökad förståelse för hur rytm, artikulation och stavelseval formarimprovisationen. Arbetet gav även nya insikter om mitt eget uttryck och medvetandegjordevilka stavelser och ljud som är ändamålsenliga. Det har lagt grunden för fortsatt utveckling aven personlig scatvokabulär
Initial Inventory Optimization for Spare Parts With Sporadic Demand : A Literature-Based Analysis of Models and Methodologies
No full textThe oil and gas industry is highly sensitive to production interruptions, where downtime caused by missing spare parts can lead to significant financial and operational consequences. To mitigate these risks, companies maintain high inventory levels, especially during the start-up phase of new offshore platforms. However, this practice results in substantial capital costs and long holding times. The purpose of this study is to investigate how the inventory management of repairable spare parts with sporadic demand can be improved during the initial stages for offshore platforms. Through a case study conducted at Company X, the current model based on Markov chains for evaluating inventory for operational systems was examined and compared with approaches from existing literature. The findings suggest that the Markov methodology is well suited for further development at the spare part level. Additionally, the study identifies potential enhancements such as standardized scenario planning and weighted decision-making based on criticality. The study concludes that extending the Markov model, combined with structured scenarioplanning and expert input, provides a feasible path forward for optimizing initial spare part inventory levels. These findings contribute to the limited body of research on spare parts inventory management in the oil and gas sector and may serve as a foundation for future development of more cost-efficient inventory strategies.Olje- och gasindustrin är mycket känslig för produktionstopp, där stillestånd orsakat av saknade reservdelar kan leda till betydande ekonomiska och operativa konsekvenser. För att minska dessa risker hålls höga lagernivåer, särskilt under uppstartsfasen av nya projekt som offshoreplattformar. Detta resulterar dock i stora kapitalkostnader och långa lagertider. Syftet med denna studie är att undersöka hur lagerstyrningen av reparerbara reservdelar med sporadisk efterfrågan kan förbättras under den inledande fasen av offshoreanläggningar. Genom en fallstudie hos Företag X analyserades den nuvarande modellen, som bygger på Markovkedjor för att utvärdera lagerhållning på systemnivå. Modellen jämfördes med metoder från befintlig forskning. Resultaten visar att Markovmetoden är väl lämpad för vidareutveckling på reservdelsnivå. Studien identifierar även möjliga förbättringar såsom standardiserad scenarioplanering samt viktning av beslut baserat på kritikalitet. Studien drar slutsatsen att en vidareutveckling av Markovmodellen, i kombination med strukturerad scenarioplanering och expertbedömningar, utgör en möjlig väg framåt för att optimera lagernivåerna av reservdelar under uppstartsfasen. Dessa resultat bidrar till det begränsade forskningsläget kring lagerstyrning av reservdelar inom olje- och gasindustrin och kan ligga till grund för framtida utveckling av mer kostnadseffektiva lagerstrategier
Förbättring av Säkerhet: Övervakad Distanstentamen
No full textDenna kandidatuppsats undersöker hur säkerheten vid övervakade digitala distanstentamen kan stärkas utan att kompromissa med studenters integritet. Syftet är att analysera nuvarande tekniska och organisatoriska åtgärder vid Institutionen för system- och rymdteknik, Luleå tekniska universitet, identifiera brister och föreslå hållbara förbättringar. Studiens teoretiska ramverk kombinerar fyra områden: informationssäkerhet, akademisk integritet, användaracceptans samt rättssäkerhet & etik vid övervakning. Forskningsdesignen är en kvalitativ fallstudie kompletterad med kvantitativa inslag. Empirin samlades in genom två semistrukturerade intervjuer (lärare och tentamensadministratör) och en anonym webbenkät besvarad av 37 studenter; materialet analyserades tematiskt. Resultaten visar att dagens lösningar, ID-kontroll, kameraövervakning och Zoom-funktionen “All Screen Share Mode” stoppar de flesta enkla fuskförsök men lämnar kritiska luckor. Studenter kan fortfarande använda externa enheter utanför kamerans räckvidd, och autentiseringen är sårbar när bara legitimation krävs. En majoritet av studenterna välkomnar ett enhetligt tentamenssystem och ser multifaktorautentisering som legitimt, men uttrycker oro för integritetsintrång vid mer påträngande övervakning. Slutsatsen är att ett flerskiktat säkerhetsramverk krävs. Rekommendationerna omfattar: (1) ett tydligt, gemensamt regelverk för alla digitala tentor, (2) övergång till en plattform med inbyggd låst webbläsare och proctoring (t.ex. Inspera), (3) starkare ID-verifiering via BankID eller biometriska metoder, och (4) kontinuerlig skärm- och kamera övervakning som kompletteras av riktade, inte permanenta, kontroller av omgivningen. Åtgärderna bedöms minska fusk samtidigt som de uppfyller GDPR och bevarar studenternas förtroende.This bachelor thesis explores how the security of supervised digital remote examinations can be enhanced without infringing students’ privacy. The aim is to analyse the current technical and organisational safeguards used at the Department of Computer and Space Science, Luleå University of Technology, identify their shortcomings, and propose feasible, ethical improvements. The theoretical framework integrates four lenses: information security, academic integrity, user acceptance, and the legal-ethical principles governing surveillance. A qualitative single-case study design is employed, supported by quantitative data. Empirical material consists of two semi-structured interviews (a lecturer and an examinations officer) and an anonymous web survey answered by 37 students; data were examined using thematic analysis. Findings indicate that existing measures such as ID checks, webcam monitoring, and Zoom’s “All Screen Share Mode” deter most straightforward cheating attempts but leave critical vulnerabilities. Students can still exploit external devices beyond camera view, and single-factor ID verification is easily subverted. Most students favour a unified examination platform and regard multi-factor authentication as legitimate, yet they voice privacy concerns about intrusive proctoring technologies. The study concludes that a multi-layered security model is necessary. Key recommendations are: (1) a clear, department-wide policy defining permitted resources; (2) migration to an integrated platform offering locked-down browsers and built-in proctoring (e.g., Inspera); (3) stronger identity verification via national e-ID (BankID) or biometrics; and (4) continuous screen and webcam sharing augmented by targeted, non-persistent environmental checks. Together, these measures are expected to reduce malpractice while remaining GDPR-compliant and maintaining student trust
Redistribution of minor and trace elements in ore minerals in metamorphosed VMS deposits, Rävliden North, Skellefte district, Sweden
No full textThe Rävliden North volcanogenic massive sulfide (VMS) deposit, in northern Sweden underwent polyphase deformation and greenschist to lower amphibolite facies metamorphism during the Svecokarelian orogeny. This caused remobilisation and recrystallisation of ore minerals, whose composition was analysed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and electron probe microanalysis (EPMA). Sphalerite, chalcopyrite, and pyrrhotite chemistry mirrors zonation of undeformed VMS deposits. Chalcopyrite-rich mineralisation contains higher Cu, Co, In, and lower Mn concentrations than sphalerite-rich mineralisation. Besides galena, Ag occurs in sulfosalts, tellurides, antimonides, and amalgams, which possibly formed through exsolutions from α-galena in syn- to post-tectonic structures. LA-ICP-MS imaging shows Ag-rich minerals in early syngenetic pyrite, in contrast to syn-metamorphic pyrite, indicating remobilisation during deformation. Despite sampling effects accounted for through linear mixed effects (LME) modelling, the results indicate that syn-metamorphic recrystallisation and remobilisation did not lead to substantial compositional changes in ore minerals. Instead, these processes partitioned Ga between sphalerite and chalcopyrite and enriched Ag, Cd, and Sb in minerals associated with younger parageneses. Zeolite-bearing veins in the hanging wall host sphalerite with the highest Ga, Ge, Cu, and Sb contents and galena with the lowest Bi, Te, and Tl contents. An origin potentially linked to far-field effects of the opening of the Iapetus Ocean or waning Timanian orogeny is discussed based on similarities to other vein- and breccia-hosted Zn Pb deposits in Northern Sweden. This study provides the first multiple-mineral in-situ trace element dataset for a VMS deposit in the Skellefte district, enhances understanding of element redistribution during metamorphism, and identifies remobilised elements potentially vectoring mineralisation at depth. Moreover, this study enables tracing of penalty and by-product elements in downstream beneficiation processes.Validerad;2025;Nivå 2;2025-06-27 (u5);Full text license: CC BY 4.0;Funder: Boliden; Sveriges Ingenjörers Miljöfond (LTU-437-2024);</p
Utveckling av en användarcentrerad webbaserad ERP-modul för projektuppföljning – en Design Science-studie
No full textDenna studie syftar till att, genom utvecklingen av en webbaserad ERP-modul för projektuppföljning, identifiera designprinciper som kan underlätta systemutveckling inom liknande kontexter. Studien bygger på Design Science Research Methodology (DSRM) och genomfördes i fem iterationer där användare aktivt medverkade i design, demonstration och utvärdering av ERP-modulen. ERP-modulen adresserar konkreta problem i verksamheten såsom fragmenterad datahantering, bristande projektöversikt och manuella processer. Genom semistrukturerade intervjuer och tematisk analys identifierades sex nya designprinciper som kompletterar redan etablerade designprinciper. Resultatet visar att generella designprinciper inte alltid är tillräckliga och att det krävs specifika riktlinjer anpassade efter verksamhetens behov och arbetsflöden
Metal treatment in stormwater bioretention systems with high hydraulic conductivity – Designed for more efficient runoff volume capture and cold climates
No full textBioretention systems are used to treat stormwater. Using coarser filter media than commonly recommended with high saturated hydraulic conductivities may increase annual runoff volume capture, facilitate smaller filters, less overflow and adaptation to cold winters. However, this may affect water quality treatment negatively. Therefore, we investigated total and dissolved metal treatment at three full scale bioretention systems with a coarse filter material and saturated hydraulic conductivities >1500 mm/h in Malmö/Sweden. One bioretention system was designed with a coarse sand-based filter medium, another with coarse sand-based filter medium and a submerged zone and the third with a 50:50 mixture of coarse sand and pumice as filter medium. The study included 19 rain events, partly during winter season when road salt was applied. The results suggest that also filter media with high hydraulic conductivity can be an effective option when metal treatment is targeted. The two systems with coarse sand filter media treated total metals effectively with median removals >80 % for Cu, Pb and Zn and median removals >35 % for Ni and Cr. Dissolved metal treatment was variable reaching from effective treatment for dissolved Cu, Pb and Zn with median removals >60 % to overall leaching of dissolved Cd, Ni and Cr. Applying a submerged zone did not showed benefits for total or dissolved metal removal. Further, treatment of total and partly dissolved metals was significantly impaired due to pumice addition of the filter media, discouraging pumice as a filter media amendment. Coarser filter materials could be recommended for sites with space limitations or when frozen ground is expected in winter. Further, they can generally reduce clogging risks and untreated overflows.Validerad;2025;Nivå 2;2025-06-30 (u5);Full text license: CC BY 4.0;</p
Modularity for circular economy: Four circularity pathways for industrial firms
No full textTransitioning toward improved circularity is a complex challenge for industrial firms, where modularity is emerging as a promising strategic approach. Although modularity has been acknowledged in prior circularity research, the current understanding of the specific practices industrial firms can adopt and the corresponding capabilities they must build to support modularity is limited. Addressing these gaps, this study adopts a multiple case study with data from 47 informants in 11 Southeast Asian power sector firms and their ecosystem partners. The analysis identifies two modular strategic orientations: traditional modularity architectures and complex modularity practices. It also identifies two capability-building approaches named: internally driven capability development and ecosystem-enabled capability enhancement. By examining the interlinkages among these, we propose a framework comprising four circularity pathways, modularity innovation pathway, alliance-driven pathway, organizational embedding pathway and circular leadership pathway, that offer novel insights into how varying configurations shape circular benefit realization. These findings contributes to circular economy literature by conceptualizing modularity as a strategic orientation and articulating how diverse pathways support circular transformation. It further extends modularity research by linking it to capability building and circular benefits beyond traditional operational domains. The study offers actionable managerial implications for manages engaged with circularity, sustainability and operations in traditional industrial firms seeking improved circular benefits.Validerad;2025;Nivå 2;2025-06-30 (u5);Full text license: CC BY 4.0;</p