| 1. |
- Cordova, Stephanie S., 1988-
(author)
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Utilizing CO2 from biomethane production : Sustainability and climate performance
- 2023
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Licentiate thesis (other academic/artistic)abstract
- Biogas solutions offer many benefits for the environment and society, including organic waste treatment as well as being an enabler for energy and nutrient recovery. The products of anaerobic digestion are a biogas, which contains a share of 30 to 50% carbon dioxide (CO2) and 50 to 70% methane, and a liquid remanent, rich in nutrients. The biogas can be upgraded by removing the CO2 to increase the energy content, producing biomethane. At present, CO2 is considered a waste in biomethane production systems, and hence it is emitted into the atmosphere. Nevertheless, biogas upgrading technologies separate a pure-grade CO2 and, likewise, carbon capture processes, providing a pure CO2 flow that can be stored or utilized. Compared to storage, carbon capture and utilization (CCU) technologies deliver valuable carbon-based products required to sustain human activities. The valorization of green CO2 could aid the transition towards defossilization of the economy. Indeed, several CO2 utilization technologies could be incorporated into biomethane production systems, but there is still a limited understanding of the available alternatives and their potential impacts on biomethane systems.This thesis aims to investigate the integration of CO2 utilization technologies in biomethane production systems by revealing its potential, identifying alternatives, and assessing the impacts of the integration. Using Sweden as an example, scenarios of future biomethane production were employed to estimate the potential CO2 available for utilization. To complement the analysis, a qualitative approach made possible the identification of aspects that could affect CO2 utilization in biomethane production. Moreover, a multi-criteria analysis (MCA) framework was developed to identify relevant indicators for assessment and available alternatives for CO2 utilization. The research also includes a life cycle assessment (LCA) to evaluate the climate performance of relevant CCU alternatives in the biomethane production system.Results show that 160 kt of CO2 could be obtained from biomethane production in Sweden, which could potentially increase threefold from 2020 to 2030. The evaluation of alternatives for CO2 utilization includes environmental, technical, economic, and social criteria with sound indicators within an MCA framework. Indicators to evaluate each criterion provide valuable information to identify feasible and sustainable alternatives that can be integrated into biomethane plants. The identified alternatives with a high readiness level are additional methane through methanation, horticulture, mineral carbonates, fuels, pH control, bulk chemicals, and liquefied CO2 for direct use. The results provide information to decision-makers in relation to considerations to take before implementation, like energy requirements, the existence of regulations and standards, and uncertainty. In terms of the climate performance of biomethane with the inclusion of CCU alternatives, the results show a possible reduction of CO2 emissions that depends on the possibility of substituting fossil-based products. The investigated alternatives all result in lower emissions, but concrete curing and methanation using renewable hydrogen produce the best results.To conclude, the potential future increase of green CO2 from biomethane in Sweden creates opportunities to substitute fossil carbon in current applications and mature conversion pathways. Moreover, the inclusion of CCU in biomethane production contributes to reducing biomethane system emissions and diversifying its products. Possible alternatives of CCU that can be integrated into biomethane production systems in the short term include methanation and concrete curing. Other alternatives could be possible but present lower performance and higher uncertainties at the moment.
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| 2. |
- Svantesson, Mats, 1975-
(author)
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Self-supervised deep learning and EEG categorization
- 2024
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Doctoral thesis (other academic/artistic)abstract
- Deep learning has the potential to be used to improve and streamline EEG analysis. At the present, classifiers and supervised learning dominate the field. Supervised learning depends on target labels which most often are created by human experts manually classifying data. A problem with supervised learning is intra- and interrater agreement which in some instances are far from perfect. This can affect the training and make evaluation more difficult. This thesis includes three papers where self-supervised deep neural networks were developed. In self-supervised learning, the input data to the networks themselves contain structures that are used as targets for the training and no labeling is necessary. In paper I, deep neural networks were trained to increase the number of-, or to recreate missing EEG-channels. The performance was at least on the same level as that of spherical interpolation, but unlike in the case of interpolation, missing data does not have to be identified manually first. Papers II and III involved developing deep neural networks for clustering analysis. The networks produced two-dimensional representations of EEG data and the training strategy was based on the principle of t-distributed stochastic neighbor embedding (t-SNE). In paper II, comparisons were made to parametric t-SNE and EEG-features obtained from time-frequency methods. The deep neural networks produced more distinct clustering when tested on data annotated for epileptiform discharges, seizure activity, or sleep-wakefulness.In paper III, the newly developed method was used to compare annotations of epileptiform discharges. Two experts performed independent annotations and classifiers were trained on these, using supervised learning, which in turn produced new annotations. The agreement when comparing two sets of annotations was not larger between the two experts than between an expert and a classifier. The analysis showed that differences in the annotations by the experts influenced the training of the classifiers. However, the clustering analysis indicated that although it was not always the exact same waveforms that were assessed as epileptiform discharges, they were often similar.The work thus resulted in different methods to process and analyze EEG data, which may have practical usefulness. Traditional agreement scores only assess the exact agreement. However, they reveal nothing about the nature of disagreement. Cluster analysis can provide a means to perform this assessment.
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| 3. |
- Aid, Graham, 1980-
(author)
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Operationalizing Industrial Ecology in the Waste Sector : Roles and tactics for circular value innovation
- 2017
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Doctoral thesis (other academic/artistic)abstract
- The take-make-waste approach to resource management in human production and consumption systems is contributing to a variety of environmental and social problems worldwide. Additionally, as the world’s population and affluence increase, so do the negative impacts of poor resource management. Lifting the waste management (WM) sector into a new phase of development, which takes its lead from the ideals of Industrial Ecology and circular economy, is seen by many scholars and practitioners as one potential to assist in alleviating these impacts. While there are many studies on how more efficient inter-organizational resource management is (or could be) constructed, there are relatively few business development studies which have explored novel approaches (from roles to tactics) that WM organizations might operationalize toward more efficient resource management.The aim of this thesis is to contribute to the development of knowledge and understanding of how the waste management sector can operationalize more effective and efficient resource management. In approaching this aim, two research questions guided the exploration of: 1) novel roles for WM and 2) support tactics for such roles. Grounded in the broader context of Industrial Ecology (IE) and Business Development, five studies were performed. Two studies, focused on the novel roles of inter-organizational resource management and high value secondary resource extraction, were performed through literature review and interviews, and market driver analysis respectively. In exploring support tactics, two design and proof of concept studies were carried out to investigate data analysis tools for inter-organizational resource management, and one long-term action research engagement project was coordinated to study hands-on inter-organizational collaboration tactics.The studies highlighted that the Swedish WM sector holds some key capacities for operationalizing (and in some cases, is already developing) the novel resource management roles identified: industrial symbiosis facilitator, eco-industrial park manager, holistic facility management, and high value resource extractor. However, depending on the portfolio of services to be performed in such roles, several capacities may need to be developed or strengthened. Main opportunities seen for these roles were – staying ahead of market developments, and aligning activities with organizational goals. The main general risk related to these roles was insufficient returns on investment. Looking forward, the main enablers identified were policy leadership for more balanced market mechanisms, increasing use of external knowledge, developing long term partnerships, lobbying, stockpiling resources, and carefully crafting new business models.The tools developed for strategically applying external information toward the identification of opportunities within new roles showed tactical potential. However, their implementation in broader development processes has yet to be fully validated. The hands-on exploration of change oriented collaboration, highlighted collective system framing and goal setting and face-to-face interaction as key activities for inter-organizational approaches within roles such as industrial symbiosis facilitator.Throughout the studies, several novel roles were investigated. Each of these roles will need to be individually evaluated by directing bodies of WM organizations, and evaluated from the organization’s vision and strategy. If certain roles are chosen to be explored in more detail, they will need to be developed within full business models - addressing issues such as income structure, internal processes and capacities to be developed, and key customers. Through applying IE and business development concepts and findings, WM organizations have possibilities to translate ambitious visions into novel offerings.
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| 4. |
- Eklund, Magnus, 1976-
(author)
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Adoption of the Innovation System Concept in Sweden
- 2007
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Doctoral thesis (other academic/artistic)abstract
- In 2001 Sweden founded the government agency of VINNOVA, named after the OECD-endorsed innovation system concept. Criticising the common assumption that countries are passive and uncritical recipients of the approaches promoted by the OECD, this dissertation tries to show that Swedish actors were in fact very active and strategic as they contributed to the national adoption of the concept. With inspiration from conceptual history and Quentin Skinner’s analysis of the rhetorical use of concepts, this study focuses on the research funding reform process between 1995 and 2001, investigating how actors trying to defend the contested institution of sectoral research used the innovation system concept to rhetorically legitimise their project. To compare these uses with earlier ways of discussing innovation in Sweden, the innovation debate that arose in relation to the industrial crises of the 1970s and 1990s has also been studied. It was found that the early Swedish innovation debate had paid little attention to the university sector. When Research 2000 in 1998 proposed that researcher-dominated research councils should be given control over sectoral research funding, a coalition in favour of industrially relevant research mobilised to protect its influence over research funding. The concept was now appropriated and used to rhetorically reframe the universities as part of a system with the main function of promoting innovations. By using the concept it was also possible to draw on the legitimacy offered by the OECD and science.
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| 5. |
- Eklund, Rasmus, 1989-
(author)
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Electrophysiological correlates of consciousness
- 2019
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Doctoral thesis (other academic/artistic)abstract
- How does the brain enable us to experience seeing or hearing a stimulus? If a stimulus is repeatedly presented at the awareness threshold, subjects will report that they are aware of the stimulus on half of the presentations. Electroencephalography (EEG) can be used to non-invasively record neural activity as event-related potentials (ERPs). The contrastive analysis of neural activity to trials rated as aware minus neural activity to trials rated as unaware reveals the neural correlates of consciousness (NCC). Research on the NCC in vision has resulted in two ERPs: an early negative difference wave (visual awareness negativity, VAN) and a subsequent late positivity (LP). Visual awareness may be reflected by one or both of these ERPs. However, the contrastive analysis (aware minus unaware) may not isolate the NCC because it arguably compares aware processing with a combination of unaware processing and no processing. In support, previous research that tried to isolate a comparison between aware processing and unaware processing found that LP was the only NCC. However, subsequent replications suggested VAN and LP as NCC. Because of these mixed results, we followed up on these studies in Study I with a preregistered design that manipulated stimulus size. Results showed VAN and LP as NCC. The findings provide evidence for VAN as an early NCC.Another main goal of this thesis was to investigate auditory awareness. In Study II, an auditory threshold task was used, and the contrastive analysis revealed an early negative difference wave (auditory awareness negativity, AAN) and LP. These ERPs are comparable to VAN and LP in vision. Because post-perceptual processes related to responding may confound the NCC in contrastive analysis, no-response tasks can be used to isolate awareness-related activity. In vision, a previous study in which the manual response requirement was manipulated showed effects on LP but not on VAN. In Study III, we used a similar task with auditory stimuli at the awareness threshold. Results suggested that AAN and LP are unaffected by the response manipulation. However, the present no-response task may not be optimal for removing post-perceptual processing because subjects need to reflect on their experience even if they do not need to respond manually. Additional analyses that attempted source localization of the AAN suggested that it is generated in auditory cortex.From a theoretical perspective, one view of these results is that VAN and AAN reflect local recurrent processing and that this is the neural signature of awareness, whereas LP reflects global recurrent processing that enables reporting. Other views suggest that VAN and AAN merely reflect preconscious processes, whereas LP and global recurrent processing reflect consciousness. The studies described in this thesis do not support one theory over the other but provide robust evidence for early neural correlates of visual and auditory awareness.
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| 6. |
- Lindfors, Axel, 1993-
(author)
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Sustainability Solutions : Lessons on Assessment and Facilitation
- 2020
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Licentiate thesis (other academic/artistic)abstract
- Sustainable development is one of the most influential visions guiding future societies. Encompassed within its vision are various domains where improvements are desirable such as, social equity, environmental degradation, climate change. In the work towards sustainable development firms, government authorities and individuals face various practical challenges tied to these sustainability domains. When facing these challenges, they may implement sustainability solutions, that is, solutions that are framed in the context of contributing to sustainable development. This thesis deals with a particular sub-set of such sustainability solutions, namely integrative and multi-functional solutions. These solutions are characterized by the ability to provide different functions through value creation within several different sustainability domains and require organisations, or units of organisations, to further integrate material, energy and informational flows in order to implement the solution. Integrative and multi-functional solutions may play an important part in the transition towards sustainable societies since the integration of material, energy and informational flows may bring with it synergistic benefits. Furthermore, the contribution of these solutions to several different sustainability domains reduces the risk of problem shifting, and it may be more cost-efficient to have one multi-functional sustainability solution than to have one for each sustainability- related challenge.However, if integration and multi-functionality are desirable characteristics of future socio-technological systems, we need ways to systematically assess them and facilitate their implementation. When it comes to the assessment, there is a need to find an assessment methodology that can handle capturing the synergistic benefits and multiple functions of such solutions. Furthermore, the methodology also has to conform to the value pluralism inherent to sustainable development. Dealing with this value pluralism when trying to assess which solution, among many, to implement can be challenging as comparative judgements have to handle potentially conflicting value orientations, goals, empirics and ontologies. As for the facilitation of their implementation, integrative and multi-functional solutions tend to be more difficult—or at least different—to implement than traditional single-minded solutions since they require traditionally separate organisations to cooperate Therefore, this thesis aims to contribute to understanding the process of implementing integrative and multi-functional solutions. Specifically the thesis explores how to select indicators for assessment, how assessments may aid decision-makers to deal with the value pluralism of sustainable development when making comparative judgements and how to strengthen the internal capacity of groups of actors to engage in collective action.Regarding the selection of indicators, the thesis suggests two different pathways. Either one may base indicator selections on stakeholder discussions, where stakeholders come to a consensus around which indicators are important to assess, or one may base indicators on operationalising pre-defined sustainability objectives: namely, sorting, contextualising and reformulating pre-defined sustainability objectives so that they fit the purpose of the assessment. A mix of both pathways is also possible, in other words, using both stakeholder discussions and the operationalisation of pre-defined sustainability objectives to motivate and justify the selection of indicators. As for how assessments may aid decision-makers, the thesis advocates for a discursive approach based on the primacy of decision support tools over decision-making tools. Meaning that the tools should support informed decisions but not make them for the decisionmaker. Here, contributions are made in the form of motivations for the discursive, qualitative approach to decision-making and exemplify how decision support tools may be designed, and a method is presented and developed that enables this kind of informed comparative judgements. This method builds on multicriteria decision analysis methodology but makes a few key contributions to the selection of indicators (mentioned previously) and to how to compare different alternatives and judge which of the alternatives is the preferred. Finally, contributions are made to the practice of facilitating integrative and multi-functional solutions through showing how the theory of institutional capacity building can be used to guide design, development and evaluation of interventions aimed at facilitating such solutions. Institutional capacity building represents the ability of groups of actors to engage in collective action, something that seems to be often needed to implement integrative and multi-functional solutions. Historically, this theory has been used to study how different events influenced the capacity of actors to engage in collective action. However, in research performed within the bounds of this thesis, the theory is expanded for use in a proactive manner, thereby contributing with insights and inspiration to others that may seek to facilitate the implementation process of integrative and multi-functional solutions.
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| 7. |
- Lönnqvist, Tomas, 1979-
(author)
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Biogas in Swedish transport – a policy-driven systemic transition
- 2017
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Doctoral thesis (other academic/artistic)abstract
- The thesis analyzes the conditions for biogas in the Swedish transport sector. Biogas can contribute to the achievement of Sweden’s ambitious targets of decreased emissions of greenhouse gases and an increased share of renewables in the transport sector, a sector that encompasses the major challenges in the phase-out of fossil fuels.Biogas development has stagnated during recent years and there are several factors that have contributed to this. The use of biogas in transport has developed in niches strongly affected by policy instruments and in this thesis, the progress is understood as a policy-driven systemic transition. Biogas has (started to) become established at the regime level and has begun to replace fossil fuels. The major obstacles for continued biogas development are found to be the stagnated vehicle gas demand, the low predictability of Swedish policy instruments, and electric car development. Moreover, the current prolonged period of low oil prices has also contributed to a lack of top-down pressure.A large share of the cheap and easily accessible feedstock for conventional biogas production is already utilized and an increased use of vehicle gas could enable a commercial introduction of forest-derived methane. However, the technologies to produce forest-derived methane are still not commercial, although there are industrial actors with technological know-how.Future biogas development depends on how the policy framework develops. Policy makers should consider the dynamics of biogas as a young sociotechnical system where different system fronts develop at a varying pace. Currently the demand side is lagging behind. However, it is necessary to maintain predictable policy support throughout the entire biogas value chain, since the system fronts that lag can vary over time. The low predictability of Swedish policy instruments indicates that policy makers should exercise care in their design to create a more robust policy framework moving forward.
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| 8. |
- Eklund, Anders, 1981-
(author)
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Computational Medical Image Analysis : With a Focus on Real-Time fMRI and Non-Parametric Statistics
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Functional magnetic resonance imaging (fMRI) is a prime example of multi-disciplinary research. Without the beautiful physics of MRI, there wouldnot be any images to look at in the first place. To obtain images of goodquality, it is necessary to fully understand the concepts of the frequencydomain. The analysis of fMRI data requires understanding of signal pro-cessing, statistics and knowledge about the anatomy and function of thehuman brain. The resulting brain activity maps are used by physicians,neurologists, psychologists and behaviourists, in order to plan surgery andto increase their understanding of how the brain works.This thesis presents methods for real-time fMRI and non-parametric fMRIanalysis. Real-time fMRI places high demands on the signal processing,as all the calculations have to be made in real-time in complex situations.Real-time fMRI can, for example, be used for interactive brain mapping.Another possibility is to change the stimulus that is given to the subject, inreal-time, such that the brain and the computer can work together to solvea given task, yielding a brain computer interface (BCI). Non-parametricfMRI analysis, for example, concerns the problem of calculating signifi-cance thresholds and p-values for test statistics without a parametric nulldistribution.Two BCIs are presented in this thesis. In the first BCI, the subject wasable to balance a virtual inverted pendulum by thinking of activating theleft or right hand or resting. In the second BCI, the subject in the MRscanner was able to communicate with a person outside the MR scanner,through a virtual keyboard.A graphics processing unit (GPU) implementation of a random permuta-tion test for single subject fMRI analysis is also presented. The randompermutation test is used to calculate significance thresholds and p-values forfMRI analysis by canonical correlation analysis (CCA), and to investigatethe correctness of standard parametric approaches. The random permuta-tion test was verified by using 10 000 noise datasets and 1484 resting statefMRI datasets. The random permutation test is also used for a non-localCCA approach to fMRI analysis.
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| 9. |
- Feiz, Roozbeh, 1975-
(author)
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Systems Analysis for Eco-Industrial Development : Applied on Cement and Biogas Production Systems
- 2016
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Doctoral thesis (other academic/artistic)abstract
- Our industrial systems are not sustainable—a major challenge which demands several types of responses. Eco-industrial development can be seen as such a response, with the goal to establish industrial systems that are both ecological and economical. Industrial Ecology is another closely related response. It is based on the idea that natural systems can be used to understand how to design sustainable industrial systems, for example, by shifting from linear industrial processes to cyclic systems, where waste streams can be avoided or minimized through utilization as raw materials for other processes. In this thesis, the possible contributions of industrial ecology/symbiosis to eco-industrial development are investigated through the use of systems analysis approaches. Two systems analysis methods are used: life-cycle assessment and multi-criteria analysis. These methods are applied on two types of industrial systems: cement and biogas.Cement is among the most used materials in the world with extensive resource consumption and environmental impact, manifested for example by the high levels of CO2 emissions. Multi-criteria analysis was used to identify, classify, and assess different measures to improve the climate performance of cement production, while life-cycle assessment was employed to quantify the CO2 emissions. Combined, multi-criteria analysis and life-cycle assessment were used for an integrated assessment of different eco-industrial development paths. Most of the feasible and resource-efficient improvement measures were related to utilization of secondary resources, for example minimizing the clinker content of the cement by replacing it with by-products from steel and iron manufacturing, or using refuse-derived fuels. Effective utilization of these secondary raw materials and fuels can be achieved through industrial symbiosis.Biogas is viewed as part of a larger transition towards a bio-based economy where resources—bio-materials and bio-energy—are used in a cascading, circular, and renewable manner. Multi-criteria analysis was used to assess the feasibility and resource efficiency of using different types of biomass as feedstock for biogas and biofertilizer production. In addition to aspects such as renewable energy and nutrient recycling, cost efficiency, institutional conditions, environmental performance, the potential per unit, and the overall potential were considered. In another study, life-cycle assessment was used to analyze the environmental performance of biogas production from source-sorted food waste using a dry digestion process. The study showed that the performance of this dry process is superior to most of the existing wet biogas processes in Sweden. The critical sources of uncertainty and their impact on the overall performance of the system were analyzed. Factors influencing methane production, as well as processes related to soil after the digestate is applied as biofertilizer on land, have the greatest influence on the performance of these systems.For both cement and biogas systems industrial symbiosis involving collaboration and better utilization of local/regional secondary resources, can result in resource-efficient eco-industrial development. Life-cycle assessment and multi-criteria approaches can serve as two complementary methods for investigating the feasibility, potential, and resource efficiency of different development paths. These approaches can provide input into decision-making processes and lead to more informed decisions.
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| 10. |
- Hatefipour, Saeid, 1970-
(author)
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Facilitation of Industrial Symbiosis Development in a Swedish Region
- 2012
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Licentiate thesis (other academic/artistic)abstract
- Today, sustainability of industrial regions and industrial networks is a challenge for business developers, policy makers, regional planners, local and governmental authorities and academic researchers. Because growing cities and industrial regions worldwide are intertwined with social, environmental, and economic advantages/disadvantages and challenges, in recent decades the ambition of industrial development and economic growth without environmental destruction has become a worldwide topic. To address this issue, a number of theories and pathways such as Industrial Ecology (IE) and its subfield Industrial Symbiosis (IS) toward sustainability of industrial regions and networks are being researched, examined and implemented.The overall aim of this thesis is to explore how local connectedness amongst locally distributed firms in industrial areas can be facilitated using industrial symbiosis theory and tools. To address the overall aim, the facilitation of IS development in this thesis includes three focus areas: 1) using IS theory and tools for categorization, characterization, and definitions of different lines of IS development; 2) matching the supply and demand potential of regional CO2 resources through industrial collaboration; and 3) using geographic information systems (GIS).Based on the research findings it is concluded that one approach for facilitating IS development is to apply IS theory and tools in an industrial region to find out whether any forms of IS already exist and what definitions of IS fit the area. Furthermore, it is also concluded that another approach for facilitating IS development could be matching the supply and demand potential of resources within industrial collaborations. However, availability and provision of relevant data and information plays an important role. In addition, it is seen that handling and developing existing regional data and information into a GIS-based format could contribute to facilitation of IS development. In general, it is seen that facilitating mechanism and facilitating organization are available, and should be coordinated.
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