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Energy, Structures, Metals, and Fluids: A Mineral Systems Study of Cu ± Au Mineralization in the Kiruna Mining District
No full textIn light of the increased demand for raw materials to support the transition away from a fossil-fuel society, mineral exploration for future raw material sources is imperative, requiring a holistic mineral systems approach. This thesis focuses on the Pahtohavare area in the Kiruna mining district where three epigenetic Cu ± Au deposits of unknown age and structural setting occur within 0.5 km of a pre-orogenic stratiform Cu (Fe ± Zn) deposit, 2 km of the Rakkurijärvi iron oxide-copper-gold (IOCG) deposit, and 5 km of the giant Kiirunavaara iron oxide-apatite (IOA) deposit, which may have shared mineral system ingredients during ore formation. The aim of the thesis is to characterize the mineral system ingredients of the epigenetic Pahtohavare deposits utilizing an up-to-date regional tectonic framework and to assess parallels between other mineral systems in the district. The following ingredients were investigated in this study: 1) driving force, using U-Pb zircon geochronology of local igneous intrusions, 2) transport pathways and structural traps, utilizing structural analysis and field mapping, 3) metal sources, based on sulfide trace element and carbonate REE geochemistry, and 4) ligand and fluid sources, using S, Sr, and Nd-isotope analyses. U-Pb zircon geochronology of intrusions in the district where Cu-mineralization is spatially proximal yields ages unanimously from the early phase of the Svecokarelian orogeny (ca. 1923-1867 Ma including age uncertainties). These ages suggest magmatism provided a thermal energy drive for the mineral systems developing during this time such as the Kiirunavaara IOA and Rakkurijärvi IOCG. Structural analysis and petrographic investigation from the Pahtohavare area show that the host rocks for the Pahtohavare deposits are folded into a noncylindrical, SE-plunging anticline and that cleavage measurements mirror the fold geometry. Foliation trails, mylonitic fabrics, and porphyroclasts with pressure shadows characterize the S0/S1 fabric as tectonic and constrains the fold as F2, indicating the folding event occurred during the late phase of the Svecokarelian orogeny (ca. 1.81-1.78 Ga). The epigenetic Pahtohavare deposits sit in brittle-ductile second-order structures that cross cut earlier foliation and the F2 fold, indicating that the deposits formed ca. 80 m.y. after the IOA and IOCG deposits in a distinct tectonic regime. Petrographic investigation of microstructures identifies remobilization textures linking the pre-orogenic stratiform Cu (Fe ± Zn) and late-orogenic Pahtohavare Cu ± Au deposits. Comparison of Co/Ni ratios between structurally constrained early and late sulfide generations (0.1-10 vs. 0.1-100) indicate the late-orogenic fluids were capable of efficiently transporting and concentrating Co, implying hot and saline conditions. However, a weak Co/Ni ratio mixing trend between the two generations suggest the late-orogenic fluids primarily sourced metals from the pre-existing host rocks and sulfides, rather than an external reservoir. This is supported by flat REE (chondrite normalized) patterns from ore-related carbonate, reflecting a source from the mafic host rocks. Both the pre- and late-orogenic sulfide generations have overlapping δ34S values ranging between ca. -20‰ and ca. -5‰ to near-zero values. The sulfur source for both mineral systems likely originated from local graphite schist horizons (ca. -22‰ to -21‰) and the volcanic host rocks. 87Sr/86Sr values for ore-related carbonates from the epigenetic Pahtohavare deposits are radiogenic (ca. 0.7095-0.7154) and form a mixing trend with strongly radiogenic (ca. 0.7134-0.7740) non-ore-related syn-sedimentary carbonate in biotite-altered rocks. This suggests a metamorphic fluid derived from crustal and Rb-rich rocks was responsible for the formation of the ore-related carbonate. Therefore, the Pahtohavare epigenetic deposits are suggested to have formed from metamorphic fluids during prograde metamorphism modified by the pre-enriched and altered host rocks in the Pahtohavare area. The results of this thesis suggest that late-orogenic tectonism played a key role in reactivating mineral system ingredients, highlighting the potential of second-order structures near pre-existing mineral deposits as a strategic exploration target for Cu-mineralization in the region.
Konstruktionsprinciper för lindningsdorn : Produktutveckling inom fiberlindningsprocessen
No full textDetta arbete undersöker fiberlindningsprocessen med fokus på konstruktionsprinciper för fiberlindningsdorn. Projektet har genomförts i samarbete med Hitachi Energy Sweden AB, Composite och bygger på Ulrich & Eppingers produktutvecklingsmodell, där nya tillvägagångssätt har utvecklats samtidigt som befintliga konstruktioner har analyserats genom teoretiska modeller och praktiska tester. Resultaten visar att nuvarande konstruktioner har vissa begränsningar och att det finns flera möjliga strategier för att vidareutveckla fiberlindningsprocessen. Dessa insikter kan i framtiden bidra till mer robusta konstruktioner och optimerade tillverkningsprocesser.This work investigates the filament winding process, focusing on the construction principles of winding mandrels. The project was conducted in collaboration with Hitachi Energy Sweden AB, Composite and followed Ulrich & Eppinger’s product development method, where new approaches were explored while existing constructions were analyzed through a combination of theoretical modeling and practical testing. The results indicate that current winding mandrel designs have certain limitations and that there are multiple potential strategies for further improving the filament winding process. These insights can in the future contribute to more robust designs and optimised manufacturing processes
A comparative study of student perceptions on generative AI in programming education across Sub-Saharan Africa
No full textIn today's era of technological evolution, programming education is crucial for shaping the future workforce and fostering innovation. However, access to quality computer science education remains a significant challenge with Sub-Saharan Africa nations experiencing a pronounced digital divide. Despite growing interest in technology, these countries struggle with unequal access to educational resources. AI-driven tools like ChatGPT, Codey, and GitHub Copilot offer personalized learning experiences that could democratize access to knowledge and reshape programming education. This quantitative study examines the impact of these AI tools on fostering inclusive education in Kenya, Nigeria, and South Africa. It involves 322 university students, using purposive sampling and online questionnaires. Various quantitative analyzes, including descriptive statistics, country-wise comparisons, one-way ANOVA, Kruskal–Wallis tests, and correlation analysis, were conducted. The study reveals students’ motivations for programming, their attitudes towards AI-driven educational tools, and the perceived impact on equity, diversity, and inclusion. Significant variations were found in attitudes based on educational level and country of residence, highlighting the need for tailored strategies to enhance the inclusivity and effectiveness of AI-driven programming education tools.Validerad;2025;Nivå 2;2025-03-19 (u5);Full text license: CC BY 4.0;</p
Lithogeochemistry and origin of the komatiites from Mundonguara mine in the Manica greenstone belt, Mozambique
No full textThe Manica greenstones belt in western Mozambique constitutes the eastern extension of the Odzi-Mutare greenstone belt in Zimbabwe that is one of several Archean greenstone belts within the Zimbabwe Craton. These greenstones are in Mozambique constituting the Manica Group and are subdivided in two main lithostratigraphic units: The Macequece Formation and the Vengo Formation. The former is hosting the Mundonguara Cu-Au mine and is dominated by volcanic rocks, while the younger Vengo Formation is consisting of epiclastic sedimentary rocks. This paper considers the character and origin of the ultramafic, mafic, and felsic rocks within the Macequece Formation. They include peridotitic komatiite, pyroxenitic komatiite, komatiitic cumulate rocks, gabbroic dykes, rhyolitic units, and a granitic rock intruding the komatiites. Samples of these rocks have been collected from outcrops and drill cores and are investigated through petrographic studies of thin sections and whole rock geochemistry including major and trace elements to interpret the geological environment and tectonic setting.The supracrustal rocks are metamorphosed to greenschist facies and the komatiites consists of varying proportions of serpentine, talc, chlorite, and amphibole. Primary features are partly preserved, with spinifex, vesicular, and cumulate textures. The komatiites are variously affected by carbonate alteration and deformation and the rhyolitic rocks are mostly strongly silicified. The komatiites are of the Al-undepleted type, with a MgO content of 25–45 wt %, while the mafic intrusions are tholeiitic in character, varying from gabbronorite to diorite in composition. Trace element diagrams used for interpretation of tectonic setting gives ambiguous results that could be an effect of crustal contamination of the ultramafic and mafic magmas. Using diagrams less sensitive to crustal contamination suggests the mafic and ultramafic magma to have a mantle source Minor rhyolitic rocks are chemically similar to granitic rocks intruding the komatiites and might have a mainly crustal magma source. This suggested that the Manica greenstones belt formed from magmas generated by mantle plume activity in a continental rift setting and were deposited on older Archean continental crust. These rocks are tentatively correlated with the Bends or Brookland formations belonging to the 2.9–2.8 Ga Mtshingwe Group in the Belingwe greenstone belts in Zimbabwe.Validerad;2025;Nivå 2;2025-03-20 (u4);Fulltext license: CC BY</p
Crystal orientation-induced Al grain coalescence coarsening during isothermal semisolid annealing of Al-15 wt% Cu alloys under high magnetic fields
No full textAl-15 wt% Cu binary alloys were isothermally annealed in a semisolid state with and without a 10 T magnetic field. The influence of the magnetic field on the 2D morphology and 3D distribution of α-Al grains was investigated. The coarsening mechanism under a high magnetic field was proposed based on microstructural analysis, coarsening kinetics calculations, and interfacial energy calculations. The size of the α-Al grains was increased, and the coarsening rate was significantly accelerated by the magnetic field. Meanwhile, more α-Al grains contacted each other and started coalescing. The grain size distribution revealed that the coarsening mechanism shifted from Ostwald ripening at 0 T to a combination of the Ostwald ripening and migration-coalescence at 10 T. The accelerated coarsening rate may be attributed to an increase in interfacial energy from 0.143 to 0.213 J m−2 under the high magnetic field. Significant Cu clustering was observed between coalesced grains at 10 T, which could further demonstrate the accelerated coarsening rate. Additionally, the magnetic field induced the rotation of adjacent grains via magnetic torque, reducing their misorientation and subsequently enhancing their coalescence. This study elucidated the mechanism of orientation-induced grains coarsening under a high magnetic field, providing a novel methodology for controlling metallic materials fabrication processes which undergo grains coarsening using magnetic fields.Validerad;2025;Nivå 2;2025-03-24 (u5);Full text license: CC BY 4.0;Funder: National Natural Science Foundation of China (U2241230, 52127807);</p
Probing dynamics and ion structuring of imidazolium ionic liquid confined at charged graphene surfaces using graphene colloid probe AFM
No full textDriven by the potential applications of ionic liquid (IL) flow for charging graphene-based surfaces in many emerging technologies, recent research efforts have focused on understanding ion dynamics and structuring at IL–graphene interfaces. Here, graphene colloid probe (GrP) atomic force microscopy (AFM) was used to probe the dynamics and ion structuring of 1-butyl-3-methylimidazolium tetrafluoroborate at graphene surfaces under various bias voltages. In particular, the AFM-measured nanofriction provides a good measure of the dynamic properties of the ILs at graphene surfaces. Compared with the IL at the unbiased graphene surface (0 V), the charged graphene surfaces with either negative (–1, –2 V) or positive (+1, +2 V) voltages favor a reduction in the friction coefficient by the IL. A higher magnitude of the bias voltage applied on the graphene surface with either sign (–2 or +2 V) results in a smaller friction coefficient than that at –1 and +1 V. In combination with the AFM-probed contact stiffness, adhesion forces, and ion structuring force curves with an ion orientational distribution according to molecular dynamics (MD) simulations, we discovered that the unbiased graphene surface (0 V) possesses randomly structured IL ions and that the graphene colloid probe is more likely to become stuck, resulting in more energy dissipation to contribute to a larger friction coefficient. Biasing of the graphene surface under either negative or positive voltages resulted in uniformly arranged ions, which produced a more ordered ion structure and, thus, a smoother sliding plane to reduce the friction coefficient. Electrochemical impedance spectroscopy (EIS) for the IL with graphene as an electrode demonstrated a greater ionic conductivity in the IL paired with the biased graphene than in the unbiased one, implying faster ion movement at the charged graphene, which is beneficial for reducing the friction coefficient.Validerad;2025;Nivå 2;2025-06-30 (u5);Funder: Science Fund ofShandong Laboratory of Advanced Materials and GreenManufacturing at Yantai (AMGM2024F18); China Postdoctoral Science Foundation and the NationalNatural Science Foundation of China (21838004);Fulltext license: CC BY</p
Occupational therapists experiences of working with LSS-housing
No full textSyfte: Syftet med studien var att beskriva arbetsterapeuters erfarenhet av att arbeta mot LSS-boenden med fokus på personen. Metod: Studien genomfördes som en kvalitativ intervjustudie med halvstrukturerade intervjuer. Åtta arbetsterapeuter som arbetade mot LSS-boenden intervjuades. Insamlad data analyserades genom kvalitativ innehållsanalys, vilket resulterade i fyra kategorier med tillhörande underkategorier. Resultat: Resultatet presenterades utifrån fyra kategorier: Ett givande arbete men med resursutmaningar, Vikten av samspel mellan arbetsterapeuten och personen, Att arbeta med fokus på personens behov och önskemål för att skapa motivation och Att sammararbeta med andra människor runt personen är fördelaktigt men kommer också med utmaningar. Arbetsterapeuterna beskrev sitt arbete som givande och varierande, men att det också kom med utmaningar gällande tidsbrist, underbemanning och bedömningsinstrument. Arbetsterapeuterna upplevde att personer på LSS-boenden blir bortprioriterade. Resultatet visade att arbetsterapeuterna arbetade personcentrerat och använde alternativa kommunikationsmetoder för att inkludera personerna i arbetet men att det fanns utmaningar i arbetet med att skapa personcentrerade mål. Utifrån arbetsterapeuternas erfarenheter visar resultatet att möjligheten att arbeta med meningsfulla aktiviteter är begränsade. Arbetsterapeuterna betonade vikten av samverkan med boendepersonal, anhöriga och andra professioner samtidigt som resultatet även visade brister hos boendepersonalen vilket påverkade kvaliteten på de arbetsterapeutiska insatserna. Slutsats: Slutsatsen från studien var att arbetsterapeuter kunde skapa delaktighet genom personcentrering men att det förekom utmaningar. Arbetsterapeuterna hade inte möjlighet att arbeta med meningsfulla fritidsaktiviteter som en följd av bristande resurser. Arbetsterapeuterna var beroende av att involvera boendepersonal, men deras kompetens påverkade insatserna. Författarna menar att studien kunde bidra med att synliggöra personer på LSS-boenden och uppmärksamma arbetsterapeuternas behov av stärkta resurser.
Perceptions of climate change and tourism: A deep dive into the forums of Reddit
No full textTourism contributes to climate change through CO2 emissions, and stakeholders must work together to reduce the negative impact of the industry. Therefore, this study explores online travel discussions on Reddit to investigate consumers’ beliefs regarding self-efficacy and barriers to climate change mitigation. The study relies on combining machine learning and thematic analysis. The results show that the intersection of tourism and climate change fosters extensive online engagement, indicating that many users are aware that travel and climate change are connected. However, self-efficacy was low overall, or not manifested in users’ contributions. Further, at least 10 barriers to climate change mitigation were identified. Suggestions on how to overcome such barriers and increase efficacy beliefs are discussed, and directions for future research are given.Validerad;2025;Nivå 1;2025-04-29 (u4);Fulltext license: CC BY</p
Involuntary loneliness among the elderly – experiences from occupational therapists in municipal home care
No full textSyftet med studien var att beskriva arbetsterapeuter i kommunal hemsjukvårds erfarenheter kring ofrivillig ensamhet bland äldre personer samt vilket stöd som finns att ge. För att besvara syftet har en kvalitativ ansats med fokusgruppdiskussioner använts för datainsamling. Tre olika fokusgruppdiskussioner har genomförts med tre samt fyra deltagare i varje grupp som representerade olika kommuner. Data har analyserats enligt analysprocess för fokusgruppdiskussioner vilket resulterade i två centrala teman. Det första temat Att möta äldre ofrivilligt ensamma innehöll underkategorierna Hur snabba förändringar i samhället kan leda till ensamhet hos äldre, Hur ensamhet hos äldre personer kan bemötas och Hur ofrivillig ensamhet påverkar aktivitetsförmågan hos äldre personer. Det andra temat Att samverka för ett samhälle med minskad ofrivillig ensamhet innehöll underkategorierna Hur flera samhällsaktörer i samverkan kan motverka ensamhet hos äldre personer och Hur medvetenheten om ofrivillig ensamhet kan öka i samhället. Resultatet visar att deltagarna ofta möter äldre personer som är ofrivilligt ensamma men att de tycker att det är svårt att veta hur de ska arbeta med problemet, och de ser även utmaningar med att utföra det inom ramen för deras verksamhet. De lyfter ett antal goda exempel där kommunerna arbetar för att motverka ofrivillig ensamhet men att den arbetsterapeutiska kompetensen inte återfinns där. Resultatet av studien indikerar på att det behövs mer forskning för att generera kunskap om vilka effektiva åtgärder som arbetsterapeuter i kommunal hemsjukvård kan anta för att motverka ofrivillig ensamhet bland äldre. The purpose of the study was to describe occupational therapists in municipal home care's experiences of involuntary loneliness among older people and what support is available to give. To answer the purpose, a qualitative approach with focus group discussions has been used for data collection. Three different focus group discussions have been carried out with three and four participants in each group representing different municipalities. Data has been analyzed according to the analysis process for focus group discussions, which resulted in two central themes. The first theme To meet older people involuntarily alone contained the subcategories How rapid changes in society can lead to loneliness in the elderly, How loneliness in older people can be addressed and How involuntary loneliness affects the ability to be active in older people. The second theme, To collaborate for a society with reduced involuntary loneliness, contained the subcategories How several societal actors in collaboration can counteract loneliness in older people and How awareness of involuntary loneliness can increase in society. The results show that the participants often meet older people who are involuntarily lonely but that they find it difficult to know how to work with the problem, and they also see challenges in carrying it out within the framework of their activities. They highlight a number of good examples where the municipalities work to counteract involuntary loneliness but that the occupational therapy expertise is not found there. The results of the study indicate that more research is needed to generate knowledge about what effective measures occupational therapists in municipal home care can adopt to counteract involuntary loneliness among the elderly
The Act of Patching : Musicking with modular systems
No full textThis artistic PhD project is a composer-performer oriented exploration of live electronics understood as modular musicking systems. The conceptual framework draws upon an understanding of agency that views musical instruments as real or virtual objects-in-time that come into existence through the act of musicking. The systems created and presented in the thesis are explored through various scenarios presented as patches that include compositions, performance systems, and strategies for musicking. The project seeks to gain knowledge about the co-evolutionary processes found within the acts of composing and performing with such systems. At the core of the research is an exploration of the field of tension between the relative stability and flexibility in the affordances of live electronic instruments. It presents strategies for the design of live electronic systems in order to obtain a balance between these two states, and to understand how instruments are adapted in relation to the artistic processes of composing and performing. The thesis addresses the following research questions: In what ways are my live electronic setups adapted within the acts of composing and performing? How do my live electronic instruments manifest the field of tension between stability and flexibility? What type of strategies can be used to create a predictable field of affordances of live electronic instruments? Through artistic research methods of meletē, transcription, and re-composition, the project gains a deeper understanding of when, how, and why human and non-human agents co-evolve in musicking with live electronics. It presents four core systems developed and refined within the project: Paragraph — a live coding environment, Parsimonia — a modular, digital musical instrument, the EMP Triangle — a serial and modular composition tool, and the Sinew0od feedback system — used a foundation for three transcriptions. The artistic outcomes are further studied using qualitative methods for data collection and analysis. The main contribution of this thesis is a novel understanding of live electronic musicking as co-evolutionary acts of patching. These acts entail processes of making and breaking connections between human and non-human agencies, and through patching create, transform, and manipulate compositions and performance setups, in order to achieve metastable systems. Hereby, the thesis proposes a cybernetic understanding of musicing as a process, challenging the traditional notion of fixed musical works, blurring the lines between compositions, instruments, interpretations, and performances