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Cosmic rays are ultra-relativistic particles traveling near the speed of light permeating the galaxy. Collisionless shock waves with their ubiquity throughout the universe and excellent capability of accelerating charged particles offer an explanation to the origin of cosmic rays. It is well established that the particles are predominately accelerated at young supernova remnant shocks through a mechanism called Diffusive Shock Acceleration (DSA). However, this theory only applies if the particles already have a relativistic starting energy. Therefore, the charged particles must be pre-accelerated up to relativistic energies by some unknown mechanism(s) before being injected into the cosmic ray acceleration process. This is known as the injection problem and a lot of effort has been put into resolving it over the past decades. This thesis will use spacecraft data from NASA's Magnetospheric Multiscale (MMS) mission to study electron acceleration at Earth's collisionless bow shock. In particular, we will study what mechanisms are able to accelerate electrons from solar wind thermal energies (~20 eV) up to mildly relativistic energies 10-100 keV. Paper III and Paper IV set out to study energetic electron events observed at Earth's bow shock by MMS. In Paper III, we investigate the most promising candidate for a solution to the long-standing electron injection problem, the Stochastic Shock Drift Acceleration (SSDA) mechanism. SSDA successfully describes a mechanism for electrons to be accelerated up to mildly relativistic energies. However, only one previous observation of the theory exists. Building on that study, we provide further evidence in favor of the theory by showing good agreement between predictions and observations. Observational evidence of an alternative electron acceleration mechanism is presented in Paper IV. The observation displays an increase in electron flux up to ~60 keV, and inconsistent features with the SSDA mechanism. The event exhibits bi-direct, QC 20231222

Sustainable energy systems rely on a wide range of energy sources, where an integral part is to use the available energy as efficiently as possible. District energy systems are considered a key factor as an efficient way of distributing heat and cold within urban areas and facilitating the utilization of renewable energy sources and heat recovery from, e.g., industrial plants and data centers. To achieve high-performing control and an increased understanding of the district energy system, a dynamic model of the process can be used. However, a city-scale, automatically generated, and updated model that can be used for the whole lifecycle of the plant remains a challenging problem. Large-scale physics-based models are sometimes used for planning and validation, but using the models for optimization and control, long-term simulation, or running a high number of simulation scenarios can be computationally prohibitive. In the thesis, the physics of the district energy grid is presented along with modeling, simulation, and control methods with the goal of increasing the computational efficiency and flexibility of the methods. The grid is described using graph theoretical concepts and a linear parameter-varying state-space model representation, along with an introduction to reduced-order models, heat load prediction, Gaussian process models, and feedback control for district energy systems. The main contribution of the thesis is the seven papers. Experiences, challenges, and possible methods to address the presented problems are given in the first paper of the thesis. In the second paper a method for the prediction of heat load for buildings is presented, followed by a machine learning-based method of modeling the thermal dynamics in a district heating pipe. Next, a method for reduced order modeling of district energy grids using graph theoretical methods and spectral clustering is presented in two papers. The sixth paper suggests an integrated approach to spatial and en

The purpose of this licentiate thesis is to research a few key concepts which are important in the development of high efficiency electric drives. The selected research method is quantitative, the raw data have been collected from real world measurements, both from powerlab and from train. The data is analysed and the results are presented in the thesis and associated papers. The paper in this thesis describes and evaluates the impact of SiC MOSFET inverters on the traction drive. Furthermore, the papers go into depth about losses within the traction drive and how the electromagnetic noise depends on both the inverter switching frequency and pulse width modulation method. In the papers, results from low fidelity models of both losses and noise are presented, these models offer greater insight into the mechanism behind both losses and electromagnetic noise. Understanding how the motor harmonic losses depends on the current distribution in conductors, can contribute to improved designs of both motors and inverters. An understanding of how electromagnetic noise increases when voltage harmonics coincide with the mechanical modes of resonance of the electric motor, can further contribute to improved designs of both inverters and motors. The thesis concludes that when SiC based MOSFETs inverters makes its debut into everyday trains, we can expect significant increases in energy efficiency as well as significantly reductions in electromagnetic noise.

Background Despite the challenges that caring for a child with cancer brings for parents, little knowledge is available concerning the effects on the parents’ couple relationship. Furthermore, few interventions have been designed to support parents in their couple relationship. The aim of this paper was, therefore, to explore parents’ experiences of their couple relationship while having a dependent child with cancer and the support they received from a family-based intervention, the Family Talk Intervention (FTI). Methods Data for this paper were taken from semi-structured interviews performed in a pilot study of the FTI in the context of pediatric oncology. In total, 22 couples were interviewed after participating in the FTI. The interviews were transcribed and analyzed using qualitative content analysis. Results Parents described how maintaining a couple relationship while living with childhood cancer could be very challenging and was not given the highest priority. The FTI was considered a way of providing important support to the couple and a chance for them to sit down together and listen to each other's perspectives on the situation. Parents described that the FTI had helped them gain an increased mutual understanding, sometimes also helping them to realize that they needed more extensive professional support in their relationship. Conclusions Living with childhood cancer and upholding a healthy couple relationship is challenging for parents. The FTI has the potential to support couples, mainly by providing opportunities for parents to communicate with each other. However, some couples may be in need of a tailored clinical intervention.

Given the excessive consumption of natural resources in affluent contexts across the world, this paper argues that there is a need to discuss, critique, and advance the concept of ethical consumption, which is commonly understood as involving only relatively minor practices of consumption refinement, such as acts of boycotting and buycotting. The paper does so by linking ethical consumption to the concepts of sufficiency and care and suggesting a temporal categorization. The sufficiency lens is applied to show why and how the understanding of ethical consumption cannot be restricted to that of consumption refinement but must also address consumption reduction, due to high ecological and climate footprints in many coun-tries. A temporal categorization is helpful for further expanding on this idea. Therefore, we propose understanding ethical consumption in three stages; pre-consumption, consumption and post-consumption. Finally, we emphasize the need to nurture a culture of responsibility and a sense of caring for others, including people, materials, and nature. Such a more comprehen-sive framework could help bring attention to both the promises and contradictions within ethical consumption, and some avenues for further research are suggested in the conclusion.

This paper reviews digital tools for supporting the Circular Economy (CE) in the built environment. The study provides a bibliometric analysis and focuses on computer-aided design (CAD), building information modeling (BIM), and computational plugins that can be used by practitioners. While Life Cycle Assessment (LCA) is the primary methodology for evaluating buildings' environmental performance, the study identifies tools beyond LCA, including computational methods and circularity indicators, that can support the evaluation of circular design strategies. Our review highlights limitations in tools’ functionalities, including a lack of representative data for LCA and underdeveloped circularity indicators. The paper calls for further development of these tools in terms of interoperability aspects, integration of more sources of data for LCA and circularity, and possibilities for a comprehensive evaluation of design choices. Computational plugins offer greater flexibility, while BIM-LCA integrations have the potential to replace dedicated LCA software and spreadsheets. Additionally, the study identifies opportunities for novel digital methods, such as algorithms for circular design with various types of reused building elements, and sharing of digital twins and material passports. This research can inform future studies and support architects and engineers in their efforts to create a sustainable built environment., QC 20231204, ReCreate project (Horizon 2020 grant no. 958200)

Given the excessive consumption of natural resources in affluent contexts across the world, this paper argues that there is a need to discuss, critique, and advance the concept of ethical consumption, which is commonly understood as involving only relatively minor practices of consumption refinement, such as acts of boycotting and buycotting. The paper does so by linking ethical consumption to the concepts of sufficiency and care and suggesting a temporal categorization. The sufficiency lens is applied to show why and how the understanding of ethical consumption cannot be restricted to that of consumption refinement but must also address consumption reduction, due to high ecological and climate footprints in many coun-tries. A temporal categorization is helpful for further expanding on this idea. Therefore, we propose understanding ethical consumption in three stages; pre-consumption, consumption and post-consumption. Finally, we emphasize the need to nurture a culture of responsibility and a sense of caring for others, including people, materials, and nature. Such a more comprehen-sive framework could help bring attention to both the promises and contradictions within ethical consumption, and some avenues for further research are suggested in the conclusion.

In early 20th century Sweden, people categorised as “feeble-minded” were regarded as a threat to society. Social control and eugenic ideas were manifested in the form of, e.g., sterilisation and long-term internment. Contemporary tendencies of psychiatrisation led to differentiating people with disability according to their age, gender, and social characteristics. Based on a social constructivist perspective, this paper aims to demonstrate how the subcategorisation “degenerated asocial feeble-minded (asocial imbeciles)” emerged in the 1920s, and what approaches existed to deal with this group. To address this issue, contemporary green papers, professional literature, and archive documents were used as historical sources. The results reveal efforts to found state-run island institutions on the Swedish coast and in the inland Lake Vättern. Due to adverse geographical conditions such as, e.g., freezing of the surrounding water, these plans could not be realised, and eventually out-of-use military barracks were converted into homes for this undesirable group of people. However, the planning process for the island institutions emphasises the dominant motivation to protect society by means of exclusion, supported by the argument that isolation would be in the best interest of the affected persons. The findings underline tendencies of ambivalent modernisation in the nascent Swedish welfare state.

Much recent research on climate change mitigation has focused on carbon intensities, i.e. emissions per unit of economic value, to better understand interrelationships of decarbonization with value. This paper studies large tourism enterprises, which account for a large share of tourism's emissions. Based on annual reports, the paper evaluates greenhouse gas emission and revenue interrelationships for a total of n = 29 large tourism companies including airlines, cruise lines and accommodation businesses. Together, these companies represent about 13% (365 Mt CO2) of global tourism emissions, generating revenues of US$477 billion (in 2019). The paper tracks their total emissions and emission intensities over the period 2015–2019, revealing that large tourism firms are not on track to net-zero. Results show considerable differences in emission intensities between the three tourism subsectors and between individual firms within the subsectors. These findings are discussed against emission reduction needs to mid-century. There is strong evidence that continued growth at industry's expected rates represents an insurmountable barrier to net-zero, contradicting industry narratives of progressively and successfully engaging with climate change mitigation.

The purpose of this paper is to analyze the mechanism for the interplay of deterministic and stochastic models for contagious diseases. Deterministic models for contagious diseases are prone to predict global stability. Small natural birth and death rates in comparison to disease parameters like the contact rate and the removal rate ensures that the globally stable endemic equilibrium corresponds to a tiny average proportion of infected individuals. Asymptotic equilibrium levels corresponding to low numbers of individuals invalidate the deterministic results. Diffusion effects force probability mass functions of the stochastic model to possess similar stability properties as the deterministic model. Particular simulations of the stochastic model predict, however, oscillatory patterns. Small and isolated populations show longer periods, more violent oscillations, and larger probabilities of extinction. We prove that evolution maximizes the infectiousness of the disease as measured by the ability to increase the proportion of infected individuals. This holds provided the stochastic oscillations are moderate enough to keep the proportion of susceptible individuals near a deterministic equilibrium. We close our paper with a discussion of the herd-immunity concept and stress its close relation to vaccination-programs.