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Temporal Synchrony Across Trophic Levels : Linking Vegetation Green-Up, Caterpillar Phenology and Breeding Timing in Ficedula Flycatchers
No full textClimate change brings with it many changes throughout natural ecosystems. One of the manyimpacts it has is changes to trophic interactions, especially between closely interactingspecies. One such interaction is the Collared flycatcher (Ficedula albicollis) which attemptsto match the hatching of their young to the peak abundance of their preferred prey, leaf eatingcaterpillars. The caterpillars in turn attempt to synchronize their egg hatching to the bud burstof their host trees. However, since each trophic level may respond differently toenvironmental cues such as temperature, climate change may cause phenological mismatch. Being phenologically mismatched can have a negative effect on fitness and understandinghow the trophic levels of deciduous trees, leaf eating caterpillars and flycatchers interact isimportant to understand the effects of climate change. In this study, this will be investigatedby using remotely sensed data on tree phenology and data on temperature to model caterpillaroccurrence. This model will in turn be used to investigate how the flycatcher breedingperiods are matched/mismatched to the caterpillar occurrences and the effect of mismatch onoffspring fitness. Our results show that caterpillar phenology is more strongly influenced bytemperature than by vegetation green-up. We also find that flycatchers whose breeding ismismatched with the peaks in caterpillar abundance experience negative fitness consequencescompared to flycatchers breeding more in synchrony with the caterpillar phenology.Furthermore, rising temperatures caused by climate change is found to increase thephenological mismatch, hinting at potential risks for the flycatchers in the future. Finally, wedemonstrate that remotely sensed tree phenology is a useful tool in predicting the occurrenceof caterpillars, providing possibilities for studying current and historical trophic interactions.Our findings highlight the importance of phenological mismatch in this study system andsuggest potential adaptive responses in flycatchers that warrant further investigation
Offline Planning for Autonomous Forest Regeneration of Mixed Tree Species
No full textSweden has 23.4 million hectares of productive forest land, primarily managed through even-aged forestry, with 96% of nursery seedlings being Scots pine and Norway spruce. Regeneration efforts are supported by mechanized site preparation techniques, such as mounding and disc trenching. However, the reliance on monocultures increases vulnerability to pests, pathogens, and climate-related stress. Mixed-species regeneration offers significant ecological and economic benefits but introduces operational complexity and higher costs. Despite its labor intensity, manual planting remains the dominant method, especially for small private forest holdings, due to its affordability. This research seeks to advance sustainable forest regeneration by integrating automation and digital decision-support tools. While commercial mechanized solutions have been tested in Nordic countries since the 1960s, high operational and investment costs, coupled with the relatively low cost of manual planting, have limited the widespread adoption of mechanized planting. Recent autonomous planting initiatives, such as Autoplant and Södra BraSatt, demonstrate the potential to improve safety and efficiency while reducing environmental impact. When paired with intelligent planning tools, these systems facilitate species diversification and enable site-adapted regeneration strategies, offering a promising future for sustainable forestry practices. A primary contribution of this study is the development of the Digital Precision Planning Tool (DiPPT), which determines the distribution of mixed-species planting based on species-specific site productivity and user-defined density constraints. By using site index maps, DiPPT generates spatially explicit planting maps through either a productivity method or an iterative balancing process tailored to user constraints. The tool allows users to optimize the placement of species adapted for within-site variations, promoting biodiversity and improving forest resilience, and sustaining site productivity. To advance automation in forest operations, a metaheuristic coverage path planner (CPP) was developed specifically for forest terrain, aiming to minimize travel distances for ground-based vehicles. Using a Genetic Algorithm (GA), the CPP considers roll, pitch, and soil moisture thresholds to ensure paths are navigable safely. It was tested on both synthetic and real terrains, demonstrating its effectiveness to safely plan paths through challenging sites. Tests on steep terrain showed that the genetic algorithm successfully navigated the terrain while minimizing vehicle path length and ensuring operational safety. Since the CPP with GA took a long time to calculate, an improved CPP named TerraTrail was developed as a faster alternative. TerraTrail was later evaluated alongside another CPP, Pathfinder, for both autonomous planting operations and as a support tool for manual operators. These tools utilized Digital Elevation Models (DEM), Depth-to-Water (DTW) maps, and vehicle kinematics to generate terrain-aware routes, offering coverage and path efficiency comparable to that of manually operated vehicles. Tests with real-world data from a manually operated planting machine, PlantMax, showed that both Pathfinder and TerraTrail achieved better coverage compared to manual planting systems. On average, TerraTrail achieved up to 18% higher coverage than the manually operated PlantMax, with a similar path distance when working under constrained environmental conditions (e.g., wet zones and steep slopes). Similarly, Pathfinder demonstrated up to 19% improvement in coverage and a 14% reduction in normalized path length compared to PlantMax, highlighting the efficiency of automated coverage path planning. Together, these advancements tackle key challenges in autonomous forest regeneration, focusing on decision-making and CPP. By integrating digital planning tools, automation, and CPP, this research helps offload forest managers, enabling better on-site decisions and improving biodiversity and forest resilience. This thesis promotes ecological sustainability by supporting the planting of mixed tree species instead of monocultures, increasing coverage for planting vehicles, and minimizing path distances, which in turn supports economic sustainability. Additionally, autonomy allows operators to work remotely, improving safety and reducing full body vibrations, which contributes to social sustainability.Trees For M
Vacuum Membrane Distillation for Desalination: Experimental and Theoretical Investigations Using Inorganic Membranes
No full textDevelopments in the desalination technologies have been driven not only to meet the increasing demands for freshwater, but also to reduce the energy demand and cost of the process and to make desalination more sustainable. Challenges facing the desalination industry include the salinity limits of commercial processes such as reverse osmosis (RO) and brine management issues. The membrane distillation process is positioned as an emerging zero liquid discharge (ZLD) technology, yet its large-scale implementation is hindered by the low water fluxes, poor long-term stability, and high production costs of membrane materials along with the low thermal energy efficiency of the process. The aim of this thesis was to develop and assess membrane materials with high permeability, long-term stability and scalability prospects to reduce the energy and costs associated with desalination. To fulfil this aim, the integration of experimental evaluation of novel membrane materials with numerical modelling was conducted to improve understanding of factors hindering the widespread implementation of desalination technologies, including vacuum membrane distillation (VMD) and pervaporation (PV), and to gain insights for guiding future material design strategies. Ceramic membrane materials, which exhibit favorable thermal and mechanical properties for VMD applications yet are sparsely represented in the literature, were evaluated for their feasibility for large-scale deployment. Selected alumina-based membranes with different characteristic properties were evaluated and benchmarked against a commercial polymeric membrane. A silane-based grafting method was developed and implemented for the hydrophobization of the selected ceramic membranes. Among the studied membranes were asymmetric α-alumina membranes that differ in thickness, along with symmetric anodic alumina membranes that exhibited superhydrophobic characteristics. For the short-term VMD evaluation, the developed anodic alumina membranes exhibited superior permeation properties, with fluxes as high as 316 kg/(m2·h) along with NaCl rejection above 99.9%. The water flux of symmetric membranes was successfully modelled, along with model extension to describe the performance of the asymmetric membranes. These evaluations also revealed the effect of the support used in reducing the effective transport area used for flux calculations of symmetric membranes. The long-term stability of the silane-grafted membranes was assessed through500 hours of VMD operation using a feed with different NaCl concentrations at 80°C. Independent of the feed NaCl concentration, the asymmetric alumina membranes exhibited superior stability maintaining a water flux of 50 kg/(m2·h) and NaCl rejection as high as 99.9% over 500 hours of VMD operation. These membranes also exhibited superior wetting resistance in the presence of iron oxide particulate scalants. Thinner asymmetric α-alumina membranes and the symmetric membranes displayed higher water fluxes yet were prone to scaling and eventual wetting during their long-term operation. Towards enabling the wider implementation of the VMD process, novel multi-stage VMD plant layouts with integrated energy recovery were simulated using the tubular form of the asymmetric α-alumina membranes that exhibited superior long-term stability. A techno-economic analysis of the plant layouts indicated that specific thermal energy consumptions as low as 180 kWh/m3 were feasible, along with a water recovery ratio as high as 85%. For simulations based on a prospective cost for the membranes, the levelized cost of water production was within a reasonable range of 3-8 $/m3. Furthermore, it was found that choice preference between the multi-stage VMD plant layouts is influenced by the type of waste heat source available (latent versus sensible heat sources). Furthermore, the potential of PV alongside nanofiltration as candidate processes for recovering water from a thermoresponsive draw solution in a hybrid desalination process was demonstrated. The experimental evaluation together with the simulation studies indicate the high potential of the α-alumina membranes developed in this thesis
Hydrological processes in small stormwater infiltration facilities
No full textClimate change is expected to lead to more intense and severe rainfall events in the future and thereby significantly increase the risk of urban flooding. This change, characterized by spatial and temporal changes in precipitation patterns, challenges the capacity of existing urban drainage systems, which may be exceeded by higher runoff flows than originally anticipated. Relying solely on enlarging stormwater infrastructure to address this issue is costly and may change flood risk downstream rather than effectively resolving it. Furthermore, climate change may result in prolonged dry periods, potentially causing soil compaction and reduced infiltration capacity. In cold‑climate regions, rising temperatures are projected to increase the frequency of rain‑on‑snow events and mid‑winter snowmelt, leading to more rapid runoff and elevated risks of surface flooding. These processes can also contribute to the formation of impermeable frozen soil layers, reduce infiltration, and increase the likelihood of ice‑lens formation. Given these challenges, urban drainage systems must be both adaptable and space‑efficient, capable of managing not only increased rainfall volumes and intensities but also the hydrological effects associated with snowmelt and freeze–thaw dynamics under a changing climate. As awareness of the hydrological and environmental impacts of urbanization on catchments grows, there has been a paradigm shift towards adopting green infrastructure solutions. These approaches diverge from traditional end‑of‑pipe strategies, by emphasizing more holistic and sustainable methods. This thesis reports on a combination of modelling and field experimentation aimed at providing a better understanding of the influence of local climate (e.g., humid continental, oceanic, and subarctic climates), soil permeability (e.g., spatial and temporal variability), and initial moisture content (degree of saturation) on the water retention capacity of a grass swale and a biofilter cell. These factors were evaluated on a long‑term basis using historical meteorological time series and on an event basis, using design storms to represent a range of rainfall intensities from 1‑ to 50‑year return periods. This analysis made it possible to identify conditions that lead to the occurrence of overflow events and to test the implementation of an outflow control structure that aims to increase retention capacities of grass swales. Results showed that robust estimates of infiltration rates and a clear understanding of the local climate and its influence on soil moisture dynamics are prerequisites for designing well-functioning infiltration-based stormwater facilities. Design strategies should include a trade-off between selecting permeable soils for locations characterized by evenly distributed rainfall and prioritizing surface storage for areas with intense, short-duration events. Results from field irrigation experiments demonstrated that retrofitting an existing grass swale with a controlled outflow control release can enhance its retention capacity and reduce peak flows in downstream urban areas. Additionally, a characterization of grass swale infiltration rates revealed long-term changes in infiltration—driven by sedimentation and vegetation density. While no strong statistical correlation was found between the depth of the unsaturated zone and swale infiltration capacity, lower saturated hydraulic conductivity values were observed in shallower water table conditions. The study underscores the trade-off between selecting or modifying permeable swale soils to reduce runoff and protect groundwater quality. Finally, results from snowmelt modeling in a location with a humid continental climate showed that overflow dynamics in a biofilter cell varied significantly by the event type. Rain-on-snow events were the most frequent triggers of overflows but produced the lowest overflow volumes per event, suggesting that the snowpack buffered and delayed runoff. DRIZZL
A Novel Explainable Artificial Intelligence Framework with Improved Learning Mechanisms
No full textArtificial Intelligence (AI) models are increasingly being deployed in various critical domains, such as healthcare, finance, law, and autonomous systems, resulting in remarkable benefits for the society. Due to black-box (sub-symbolic) nature, these AI models do not provide explanation of the predictive output. This lack of explanation results in lack of transparency between human and machine. Such opacity of black-box AI models, particularly deep learning architectures, is a significant concern. To address this concern, Explainable Artificial Intelligence (XAI) has emerged as a vital research area. The aim of XAI is to enhance transparency, trust, and accountability of AI models. Various post-hoc XAI tools explain the outputs of black-box AI models based on training datasets. However, the use of training datasets, rather than domain knowledge, makes such explanations proxy. A biased training dataset may lead to a misleading post-hoc explanation as well. In contrast, an explanation based on domain knowledge will be more trustworthy to an end user. Motivated by this, we propose a novel XAI framework, consisting of Belief Rule Based Expert System (BRBES), to predict output and explain it with reference to domain knowledge. BRBES represents domain knowledge with its rule base. It outperforms other knowledge-driven AI models to handle uncertainty due to ignorance. To improve the accuracy of BRBES, we fine-tune its parameters and structure through evolutionary learning. Moreover, to overcome the scarcity of labeled dataset in this learning mechanism, we integrate semi-supervised and self-supervised learning with BRBES. We explain the output of BRBES with respect to the most influential rule of the rule base of BRBES. Thus, the output of our proposed XAI framework becomes not only accurate, but also explainable. This doctoral thesis delves into the challenges and opportunities surrounding XAI in order to provide a comprehensive understanding of the AI output. It presents a novel XAI framework to provide domain knowledge based energy consumption prediction with improved accuracy, and explain this predictive output in non-technical human language. Then it deals with multi-modal air quality data by integrating deep learning model with BRBES. Moreover, to reduce dependence on labeled data for evolutionary learning, this thesis integrates semi-supervised and self-supervised learning with BRBES. This thesis presents six significant contributions. First, we conduct a Systematic Literature Review (SLR) on XAI using the PRISMA guidelines, delving into the numerous challenges and opportunities of XAI. Extensive research is conducted to explore the definition, terminologies, taxonomy, and application domains of XAI. It highlights various challenges of XAI, such as, no universal definition, trade-off between accuracy and explainability, and lack of standardized evaluation metrics. To address this lack of standardized evaluation metrics, we also propose a unified framework to evaluate XAI. Secondly, we present an innovative explainable BRBES (eBRBES) framework, which offers accurate prediction of building energy consumption phenomenon, while providing insightful explanation and counterfactual based on domain knowledge. As part of eBRBES framework, we also present a novel Belief Rule Based adaptive Balance Determination (BRBaBD) algorithm to assess the optimal balance of the proposed framework between explainability and accuracy. Thirdly, we propose a mathematical model to integrate BRBES with the Convolutional Neural Network (CNN). We leverage the domain knowledge of BRBES, and image data patterns discovered by CNN with this integrated approach. We predict air quality with this integrated model using outdoor ground images and numerical sensor data. Fourth, we integrate two-layer BRBES with CNN to monitor air quality using satellite images, and relevant environmental parameters, such as, cloud, relative humidity, temperature, and wind speed. The two-layer BRBES showcases the strength of BRBES in conducting reasoning across multiple layers. Fifth, we enhance the learning mechanism of BRBES by utilizing the extensive unlabeled energy data, along with limited labeled data. For this purpose, we synthetically generate unlabeled data through weak and strong augmentation. We then pseudo-label these unlabeled data by integrating semi-supervised self-training model with BRBES. By learning from both labeled and pseudo-labeled data, initial BRBES transitions to semi-supervised BRBES. Sixth, to conduct the learning mechanism of BRBES without relying on any labeled data, we integrate self-supervised learning with it. To this effect, we pseudo-label the synthetically generated unlabeled energy data with BRBES in the pretext tasks of self-supervised learning. Then, the initial BRBES learns deeper representation from these pseudo-labeled data, and transitions to self-supervised BRBES. We then transfer this BRBES, learned in a self-supervised approach, to the downstream task for performing regression of energy consumption. Based on the research findings of this thesis applied on two different phenomena, it can be argued that the proposed XAI framework provides prediction with greater precision, and explanation with higher interpretability.Funder: Stiftelsen Rönnbäret</p
Excavating an understanding of safety management: Experiences and perspectives from the Swedish mining industry
No full textThis thesis explores the conditions for, interpretations of and reactions to safety management strategies and practices implemented in the Swedish mining industry. The concept of ‘safety’ is depicted as one of the more important aspects of organisational management in mining industry contexts by both the mining industry itself and by researchers in related research fields. However, due to the complex nature of mining industry operations, interpretations of ‘safety’ and priorities regarding its development can vary greatly between people from different roles operating in mining workplaces. A machine operator with a more practical perspective on safety management may for example prioritise the physical safety of themselves and their colleagues and considers themselves safe when there is mutual trust and cohesion within their team. Meanwhile, managers and safety specialists with more strategic perspectives might instead focus on efforts to develop cultural values which promote safer attitudes and behaviours, and on balancing productivity with safety goals. These perspectives both seek to address important issues that safety management efforts may aim to address, yet they are characterised by different approaches to safety. While many different studies have explored safety and its management in mining contexts, the most common approach has been to consider safety based on the conceptualisations of leaders and managers. Few studies have approached safety management from the perspectives of personnel and contractor employees closer to the practical work. Fewer still are the studies that have emphasised these differences in approaches to safety in mining organisations and have examined how they can influence the outcomes of safety management efforts. The purpose of this thesis is thus to explore safety management in Swedish mining and highlight nuanced perspectives and experiences of methodologies and outcomes. In doing so, I identify how a broader understanding for and acknowledgement of the characteristics of mining industry safety management can help with addressing challenges for the continued management of safety. The empirical basis of this thesis is mainly built upon two projects conducted between 2019 and 2024 within and with the Swedish mining industry which focused on studies of safety management strategies and practices. Their contributions consisted of a total of 26 interviews with safety specialists, managers, supervisors, employees and contractor personnel from several different Swedish mining companies. In addition, these projects provided opportunities for document studies of material relating to safety management strategies and practices, and for workplace observations at some of the participating companies’ mining operations. The theoretical framework of this thesis focuses on organisational aspects which influence safety management efforts by, e.g., recommending certain approaches to management or exploring factors that can explain assumptions and behaviours relating to safety. The results show that, while safety management in the Swedish mining industry is generally perceived as having shown progress in recent years, challenges related to aspects such as communication, leadership and differing conceptualisations of safety remain. A shared characteristic of these challenges is that they relate to and involve different groups with nuanced perspectives and conceptualisations of safety. Safety management strategies may for example be difficult for employees to engage with; and physical, social and organisational separations can hinder the development of shared safety cultures between, e.g., client and contractor personnel. The experiences and examples examined in this thesis have shown how differences in expectations or interpretations can act as obstacles for effective and cohesive safety management efforts. Furthermore, this thesis has highlighted the Swedish mining industry’s normative and top-driven approaches to managing safety and safety cultures, and the challenges it faces with addressing aspects such as power relations and underlying cultural values. Ultimately, this thesis suggests that safety management efforts would benefit from seeking to understand and address the nuances between the various strategic and practical perspectives of safety involved. By encouraging communication, collaboration and mutual understanding for safety between different hierarchical levels and groups within mining organisations, these differences can be bridged and encourage more cohesive safety cultures.Denna avhandling utforskar förutsättningarna för, tolkningarna av och responsen till strategier och insatser för säkerhetsarbete som implementeras i den svenska gruvindustrins organisationer och arbetsplatser. ’Säkerhet’ som koncept skildras som en av de viktigaste aspekterna av organisatorisk styrning i gruvkontext av både gruvföretag och forskare i anknutna forskningsfält. Gruvdrift medför dock ofta komplexa organisatoriska strukturer som gör att tolkningar av ’säkerhet’ och de prioriteringar som görs gällande dess utveckling kan variera mycket mellan de olika rollerna som är aktiva på gruvarbetsplatser. En maskinoperatör med mer praktisk syn på säkerhetsarbete kanske prioriterar den fysiska hälsan av sig själv och sina kollegor, och känner sig säkrast i grupper som har utvecklat ömsesidigt förtroende och god sammanhållning. Samtidigt kan fokus för chefer och säkerhetsspecialister med mer strategiska perspektiv vara att utveckla kulturella värden inom organisationen som främjar säkrare attityder och beteenden, eller på att balansera produktiviteten med deras säkerhetsmål. Personerna i båda dessa exempel strävar efter att hantera viktiga frågor kopplade till säkerhetsarbete, men de karaktäriseras av skilda tillvägagångssätt och synsätt på säkerhet. Av dessa perspektiv är det ledares och chefers konceptualisering av säkerhet som är mest förekommande bland studier som utforskar säkerhet och system för dess utveckling inom olika gruvkontext. Få studier om gruvindustrin som utforskat säkerhetsarbete har fokuserat på anställdas och leverantörers mer praktiska tolkningar av säkerhet och synsätt på säkert arbete. Ännu färre är de studier som betonar dessa skillnader i synsätt och undersöker hur de kan påverka förutsättningarna för och resultaten av säkerhetsinsatser. Syftet med denna avhandling har därför varit att utforska den svenska gruvindustrins säkerhetsarbete för att lyfta fram nyanserade perspektiv och upplevelser av olika tillvägagångssätt och deras påföljder. På så sätt identifierar jag hur en bredare förståelse för och bekräftelse av säkerhetsarbetets kännetecknande aspekter inom gruvindustrin kan underlätta hanterandet av utmaningar för den fortsatta utvecklingen av säkerhet. Den empiriska grunden för denna avhandling byggs huvudsakligen på två projekt som utfördes mellan år 2019 och 2024 tillsammans med den svenska gruvindustrin, vars fokus var att studera strategier och insatser för säkerhetsarbete inom den industrin. Bidragen bestod av totalt 26 intervjuer med säkerhetsspecialister, chefer, arbetsledare, tjänstemän, kollektivanställda och leverantörspersonal som arbetade för flera olika svenska gruvföretag. Vidare möjliggjorde dessa projekt även för dokumentstudier av material om säkerhetsprogram och strategier, samt för arbetsplatsbesök och observationer vid några av de deltagande företagens gruvanläggningar. Det teoretiska ramverket jag nyttjade mig av för denna avhandling fokuserar på organisatoriska aspekter som har en påverkan på säkerhetsarbete och insatser för säkerhetsutveckling. Exempel inkluderar rekommendationer för ledning och styrning eller utforskande av faktorer som kan förklara antaganden och beteenden relaterade till säkerhet inom organisationer. Avhandlingens resultat visar på att många utmaningar gällande kommunikation, ledarskap och konceptualiseringar av säkerhet kvarstår för arbetet med och utvecklingen av säkerhet, trots att det upplevs ha förbättrats med tiden inom den svenska gruvindustrin. Gemensamt för dessa utmaningar är att de kan kopplas till att säkerhetsarbetet involverar olika grupper med nyanserade perspektiv av och förståelser för säkerhet. Till exempel kan strategier för säkerhetsutveckling vara svåra för anställda att involvera sig i, samtidigt som främjandet av gemensamma säkerhetskulturer mellan anställda och leverantörspersonal kan motverkas av de fysiska, sociala eller organisatoriska gränserna mellan dem. De upplevelser och exempel som studerats i denna avhandling har visat på hur skillnader i förväntningar för eller tolkningar av säkerhetsarbeten och strategier kan bidra till att förhindra utvecklingen av effektivare och mer sammanhållande säkerhetsinsatser. Vidare har avhandlingen även belyst utmaningarna för gruvindustrins normativa, ledningsstyrda säkerhetsarbete med att hantera viktiga aspekter såsom maktrelationer och latenta kulturella värderingar. I slutändan hävdar jag att den svenska gruvindustrins arbete med säkerhetsinsatser skulle gynnas av att undersöka, förstå och ta itu med nyanserna mellan de olika strategiska och praktiska perspektiven av säkerhet och säkerhetsarbete som förekommer inom fältet. Genom att främja kommunikation, samarbete samt gemensamma förhållningssätt till säkerhet mellan olika hierarkiska nivåer och grupper inom gruvorganisationer kan dessa skillnader bryggas och uppmuntra värdet av sammanhållning bland industrins säkerhetskulturer
Driving Sustainability in Manufacturing through Digital Transformation and Collaboration
No full textAs manufacturing companies confront rising environmental, social, and economic challenges, digital transformation emerges as a vital enabler of sustainability. However, achieving meaningful impact requires more than adopting advanced technologies; it demands collaborative approaches that embed sustainability into the core of the industrial value chain. This thesis examines the so-called twin transition, defined as the integration of digital transformation and sustainability, by investigating how collaboration enables the co-creation value between manufacturing companies and technology solution providers (TSPs), which design, integrate, and deliver technology solutions, as well as among TSPs themselves, thereby contributing to sustainable production. The research demonstrates how digital technologies can drive sustainability through collaborative efforts between manufacturers and TSPs. Building on theoretical insights and empirical findings, it conceptualises a value constellation in which manufacturers and TSPs collaborate to provide tailormade technology solutions that foster sustainability. This approach shifts the focus from fragmented or isolated initiatives toward a collaborative value constellation, where digital technologies are applied to improve operational performance and contribute to environmental and social outcomes. Furthermore, the thesis synthesises theoretical and empirical insights to support the twin transition, with a particular focus on how manufacturers and TSPs can collaborate and leverage digital technologies to drive sustainability. The contributions of this thesis rest on three interrelated pillars: (1) embedding value co-creation as an approach across interconnected actors to drive sustainability, (2) demonstrating how inter-organisational collaboration can align digital and sustainability agendas, and (3) leveraging strategic use of digital transformation to foster sustainability into both technological and non-technological innovation processes. By synthesising theoretical and empirical insights, this research makes contributions to the fields of innovation management, digital transformation, sustainability, and collaboration studies
Geology, magmatic evolution, and Cu-Au sulfide genesis of the Mundonguara deposit, Manica Greenstone Belt, Mozambique
No full textThis thesis presents an integrated geological study of the Mundonguara Cu-Au deposit, located within the Archean Manica Greenstone Belt of western Mozambique, which forms part of the eastern Zimbabwe Craton. The research combines petrography, lithogeochemistry, U-Pb geochronology, mineralogy, mineral chemistry, and stable isotope analysis (S, C, and Oisotopes) to develop a comprehensive genetic model and contribute to the understanding of metallogenic processes in Archean greenstone terranes. Fieldwork and geochemical analyses reveal that the Macequece Formation, which hosts the Mundonguara Cu-Au deposit, comprises Al-undepleted peridotitic komatiites, pyroxenitic komatiites, ultramafic cumulates, and intrusive mafic to felsic rocks. These units show evidence of a mantle plume origin and were emplaced in a continental rift setting. U-Pb zircon ages from intrusive and extrusive units constrain the timing of a major magmatic event to 2.94-2.91 Ga, placing the Macequece Formation within the Lower Greenstones of the Bulawayan Supergroup. A major unconformity separates it from the overlying M'Beza-Vengo Formation, recording a temporal gap of ca. 170 Ma and indicating a craton-wide tectonic transition. Additional Neoproterozoic ages (578-846 Ma) reveal overprinting by later tectono-thermal events, including those associated with the Rodinia breakup and the Pan-African orogeny. Sulfur isotope compositions of sulfides (δ³⁴S: -0.40‰ to +4.02‰) support a dominantly magmatic source, with minor crustal input. Carbon and oxygen isotope ratios in gangue carbonates (δ¹³C: -9.61‰ to -4.32‰; δ¹⁸O: +4.93‰ to +13.05‰) define multiple stages of fluid-rock interaction, from early carbonate alteration of komatiites to later Cu-Au mineralization. These isotope signatures reflect the involvement of hybrid fluids of predominantly magmatic-hydrothermal character and with minor crustal contributions. Mineral chemistry data further support this model. Chalcopyrite trace element patterns are consistent with medium-temperature hydrothermal systems (e.g., IOCG, skarn), while Ni enrichment indicates interaction with komatiitic host rocks. Pyrite compositions define two groups with contrasting Co/Ni ratio, pointing to mixing between magmatic and metamorphic fluid sources. Sphalerite Fe content yields ore formation temperatures between 280 and 335 °C, consistent with low- to medium-temperature hydrothermal systems and overlapping withorogenic gold deposits. Altogether, the data supports a hybrid genetic model for the Mundonguara deposit, involving dominantly magmatic-hydrothermal fluids, minor metamorphic contributions, and metal input from both mantle-derived and local ultramafic rocks. The system differs from classical IOCG-and orogenic gold deposits and is best interpreted as an orogenic gold deposit with atypical metal association hosted in komatiitic rocks
Performance of Lower-Carbon Concretes After High-Temperature Exposure
No full textThis research was initiated in response to the urgent need to reduce CO₂ emissions, the ongoing green transition within the building materials sector, and the persistent gap in both knowledge and practice regarding the performance of environmentally friendly concretes under high-temperature exposure. The study investigates the behaviour of concrete and paste mixtures incorporating ground granulated blast furnace slag (GGBFS) and calcium sulfoaluminate (CSA) cement following one hour of exposure to elevated temperatures. Mechanical testing, chemical analysis, including real-time monitoring during heating, and microstructural observations were used to evaluate thermal damage and to understand the materials’ response under those conditions. Various binder types, fillers, fibres, and admixtures were examined to assess their influence and to identify both strengths and limitations. The results demonstrated a beneficial effect of GGBFS in systems based on Portland cement, particularly in enhancing residual strength and thermal stability. In CSA-based systems, the inclusion of eggshell powder (ESP) was found to contribute positively to post-fire performance. On the other hand, certain admixtures caused unexpected disturbances at high temperatures, suggesting the need for careful compatibility and awareness of mix when designing thermally resistant concretes. The experimental programs were designed as an initial step toward broader exploration and formed a key component of an ongoing research effort. The findings are intended to support and complement existing studies in both academia and industry, with the goal of improving the fire resistance and overall durability of sustainable concrete materials
Smart Textiles for Stroke Rehabilitation
No full textExtensive rehabilitation after a stroke is highly important to avoid permanent disabilities. Over 60% of stroke survivors experience limited mobility in upper limb. The aim of this study was to explore how smart textiles with sEMG electrodes and bio-feedback can support upper limb stroke rehabilitation by identifying user needs and evaluate these through interviews and a focus group discussion with rehabilitation professionals. A human centred design approach was including semi structured interviews and a focus group discussion. Furthermore, low-mid fidelity prototypes were made. These were evaluated by the professionals. The most significant findings were that the technology must be simple to understand and use, it should motivate the user to perform rehabilitation, and it should enable rehabilitation including functional movements. The final result was two high fidelity prototypes that aimed to meet the three main needs identified from the semi structured interviews. Further-more, the prototypes aimed to enable home based rehabilitation. One of the proto-types targeted the function of fingers and hand which is an important function to increase the freedom and independence of stroke survivors. The second prototype was a full sleeve including electrodes targeting muscles in both forearm and upper arm to enable a wider range of movements in rehabilitation. The technology includes features to guide and support the user. One example tactile elements in the textile to help with correct position of the electrodes. The technology could enable home based rehabilitation which could decrease the high pressure on the healthcare system and save resources in both time and money. Furthermore, it could engage and motivate the patient to increase the rehabilitation outcome and the overall quality of life for stroke survivors