This thesis examines hotel worker’s experiences of organisational restructuring and job transitions during the COVID-19 pandemic. It draws on four empirical papers based on 45 semi-structured interviews conducted in a constrained labour market shaped by fluctuating demand, pandemic restrictions, organisational restructuring and extensive use of short-time work (STW). 

The analysis captures insights from hotel workers across multiple post-restructuring labour market statuses, illustrating job transitions across internal and external labour markets as well as the liminal space in between. Two papers focus on workers who remained in employment and includes experiences of extensive STW, while the other two examine workers who faced job loss. Across all groups, restructuring brought substantial changes to work and employment conditions: remaining workers faced fluctuating workloads, hours and income, as well as changed roles and reduced career prospects; redundant workers, on the other hand, often entered underemployment and faced constrained mobility, although some saw chances for a new career. 

The thesis examines outcomes for workers by integrating theories of internal and external labour markets, restructuring strategies, job transitions, and established restructuring outcomes categories: Victims, Endurers and Survivors. To capture experiences overlooked within existing frameworks a fourth category, Liminals, is introduced. To analyse these transitions, the thesis develops the Job Transition Model, a visual and analytical model grounded in theoretical and empirical insights from this thesis, applied here to understand job transitions in the context of organisational restructuring involving extensive STW implementation.  

Overall, the thesis offers a more nuanced understanding of restructuring involving STW, demonstrating the interconnected nature of internal and external labour markets, and the complex transitions workers navigate during organisational restructuring. 

Organic solar cells (OSCs) have achieved power conversion efficiencies exceeding 20%, yet their long-term operational stability remains a major challenge for commercial applications. This study investigates the photodegradation of state-of-the-art OSC materials and their impact on device performance using a combination of spectroscopy and microscopy techniques. UV-vis absorption spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), synchrotron-based X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy were employed to study chemical, structural, and morphological changes in photoactive layers exposed to AM 1.5 illumination in air.

The first part of the thesis focuses on the photodegradation mechanisms of donor and acceptor materials. Thin films of PBDB-T, Y5, PF5-Y5, and PYT were exposed to AM 1.5 illumination in air. The results show that the BDT-T unit present in PBDB-T and PF5-Y5 accelerates photobleaching, while its replacement with thiophene improves the photostability of PYT. Studies of PM6:Y6 blend revealed distinct degradation pathways. By employing long-wavelength band-pass filter illumination that selectively excites the acceptor, electron-transfer-induced superoxide formation was suppressed, and the remaining degradation occurred due to singlet oxygen via energy transfer. 

The second part of the thesis addresses the influence of photodegradation on device performance. The choice of processing solvent affected the morphology and molecular orientation in PM6:Y6 blends, but devices exhibited similar degradation rates. Incorporation of PC₇₀BM into PTQ10:Y6 blends reduced the formation of carbonyl species and improved photostability. Overall, this work provides insights into molecular- and device-level degradation pathways in high-performance OSC systems and identifies structural and compositional strategies to mitigate photooxidation processes. 

Learning complex systems in the molecular life sciences is challenging for students, in large part because of the domain‑specific language. This thesis provides insights into how domain-specific language is structured and used in upper secondary school to communicate complex molecular systems, using protein synthesis as an example. Across four studies, students’ conceptual structures and mechanistic reasoning about protein synthesis, and how chemistry and biology textbooks describe it through metaphors and domain-specific concepts were investigated. The results show that students use domain-specific concepts in fragmented clusters rather than formulating descriptions showing an integrated understanding of protein synthesis. Students and textbooks follow the central dogma of a linear process from DNA to protein and compartmentalise concepts with mRNA as a key bridging idea. Few students reach an emergent mechanistic level of reasoning, and only in isolated sub-processes. Textbooks use two main metaphor systems: Information-based and construction-based metaphors. Teaching should emphasise links between clusters of concepts and make concepts and metaphors explicit to help students develop a coherent understanding of protein synthesis.  

Digital health (DH) technologies such as mobile apps, wearable devices, and electronic health records have potential to improve healthcare outcomes by supporting efficient workflows, reducing stress for healthcare providers, and helping people manage chronic conditions more effectively. These benefits matter particularly for older adults, who often, in highly digitized societies like Sweden, depend on DH services frequently and under demanding circumstances. However, DH solutions can lose their value in practice when usability and accessibility are poor. Common problems, such as poor text readability, cluttered features, limited language support, and interactions that require speed or precision, can lead to errors and frustration, especially for older adults or those with reduced motor control. When such issues occur, DH can become less inclusive, which can limit adoption and reduce the real-world impact of otherwise well-intended services.

This thesis investigates how usability and accessibility evaluation can be made more effective and efficient, with a focus on the practical challenges of involving key target user groups, especially older adults and people with impairments. The thesis builds on interviews with DH software professionals, which highlighted limited resources and inefficient evaluation as recurring obstacles. To study these challenges further, we conducted a systematic literature review of DH usability evaluation methods and tool support, an online survey with DH usability experts on current practices and efficiency threats, and empirical, data-driven studies that begin with field studies of older adults with shaky hands performing smartphone interaction tasks and progress toward design-time imitation of touch behavior during the design of UI prototypes.

Across the studies, usability evaluation emerged as one of the key challenges in effective DH development. The survey results indicated that participant recruitment is often perceived difficult, the time and budget are often insufficient, together with gaps in knowledge about method selection and tool familiarity. The literature also showed that usability evaluation automation support is still limited and is mainly used for user performance tracking and to check compliance with accessibility guidelines. To address recruitment limitations, the thesis demonstrates how collected data on GUI interactions can be augmented with synthetic data generation approaches and then used to train imitation models of older adults’ tapping and gesture behaviors. This resulted in the User Interface Interactions Imitation (UI³) framework, which integrates “virtual older adult users” into design prototyping environment to simulate interaction patterns and surface potential usability and accessibility issues.

The thesis contributes a consolidated evidence on where and why usability evaluation, from a research and expert perspective, often becomes inefficient in practice; an overview of the current limitations in test automation and why advanced tool support is still uncommon; and a data-driven, AI-based approach that can complement traditional usability testing through design-time imitation of older adults’ smartphone interactions in UI prototypes, enabling earlier identification of usability barriers.