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Development of novel, rare earth doped lanthanum strontium cobalt ferrite ceramics, synthesized by ion-exchange promoted sol-gel processing
Full text linkLanthanum strontium cobaltite ferrite, La0.6Sr0.4Co0.2Fe0.8O3-δ or LSCF6428 is a mixed ionic and electronic conductivity (MIEC) cathode material suitable for use in solid oxide fuel cells (SOFCs) operating at intermediate temperatures (ITs) between 600 - 800 oC. In this work, LSCF6428 and rare earth doped LSCF i.e. LPSCF33428, LNSCF33428 and NSCF6428 were synthesised using the sodium alginate mediated, sol gel method and the resulting structural, porous and performance properties of sintered ceramics investigated as cathode materials for IT-SOFCs. Dried, 3 wt% alginate + metal oxide sol-gel beads were calcined at 800 oC for LSCF6428, LPSCF33428, LNSCF33428 and 775 oC for NSCF6428. XRD analysis revealed nanopowders (of ~ 40 nm crystallite size) to be in the expected rhombohedral structure for LSCF and to have between 94-96% phase purity. SEM/EDX suggest Sr deficiency and Fe enrichment of the rhombohedral phase (apart from NSCF6428) due to the presence of second phase SrCO3 and probably α-Fe2O3 (likely to be retained after calcination in air). SEM and XCT reveal that nanoparticle agglomeration results in significant microporosity. The size of the pores range from 30-50 nm, based on SEM and N2 adsorption analysis, and are similar for both the undoped and rare earth doped LSCFs. The specific surface area for the calcined nanopowders meet target requirements of between 5-7 m2 /g for SOFCs.
The calcined nanopowders were sintered at 1000 oC for 1 h to produce LSCF6428 and rare earth doped LSCF microstructures suitable for IT-SOFCs cathode materials i.e. of 70-90 % density. Microstructural analysis by nano-XCT and serial sectioning FIB-SEM reveal grain size and phase inhomogeneity not detected by XRD (the latter suggesting 70 nm crystallites in a single phase). A nanocrystalline, porous grain structure plus areas of dense, micrometre size grains and separate iron rich areas are all detected by FIB-SEM (the latter likely being the α-Fe2O3 predicted by thermal analysis of the calcined material and by magnetometry of the sintered ceramics). Overall, the sintered ceramics meet the target criteria of 25-40% porosity, with < 100 nm average crystallite size and < 100 nm average pore size by bulk measures.
Electrical symmetrical cell testing of LSCF doped with praseodymium in a half-cell format (LPSCF3342/YSZ) showed a decrease in total polarization resistance compared to an equivalent LSCF6428 half-cell, suggesting that oxygen adsorption, desorption and surface diffusion for oxygen reduction reactions at the interface of a cathode and electrolyte in a SOFC would all be improved. There is potential for further improvement if more homogeneous microstructures were to be produced. However, it is clear from this thesis that rare earth dopants such as Pr can enhance the performance of a LSCF based cathode in an IT-SOFCs
CAMHS clinician knowledge, attitudes, confidence, and treatment practices in their provision of psychologically informed interventions to gender diverse youth in the UK
No full textObjective
This thesis aimed to measure and explore knowledge, attitudes, confidence, and treatment practices among clinicians working in children and young people’s mental health services (CAMHS) when delivering psychologically informed interventions to gender diverse youth. It sought to investigate whether a model of clinical self-efficacy, knowledge, attitudes, and demographic factors predict clinician confidence delivering psychologically informed interventions to this population.
Design
A cross-sectional mixed methods online survey design was utilised to collect information on treatment practices and to examine the hypothesised relationships.
Method
A sample of 79 CAMHS clinicians completed measures of treatment approaches and adaptations, demographic factors, clinical self-efficacy, knowledge, attitudes, and confidence delivering psychologically informed interventions to gender diverse youth. The attitudes measure had a substantial amount of missing data, which led to just 53 complete cases when including this measure. Two linear regression models were conducted. Model one included the attitudes measure, and model two extracted this measure.
Results
Participants endorsed evidence-based interventions and utilised a variety of cultural adaptations. In model one, knowledge significantly predicted clinical confidence. In model two, knowledge and attitudes significantly predicted clinical confidence.
Conclusions
These findings suggest that knowledge predicted clinician confidence delivering psychologically informed interventions to this population. Moreover, affirming attitudes predicted confidence, suggesting that clinicians who hold more affirming attitudes may find delivering psychologically informed interventions to gender diverse youth easier than those who hold less affirming attitudes. However, these relationships were observed cross-sectionally, therefore, the direction of these relationships is unclear. Both models lacked enough statistical power to meaningfully measure the observed relationships, particularly model one. Therefore, results should be interpreted in the context of the study limitations. Future studies may wish to replicate the existing study prospectively, with a larger sample size, to examine the relationships over time and to compare with the present study’s findings
Deep learning-based and motion-compensated reconstruction for undersampled cardiac MRI
Full text linkModelling changes in public transport demand amid disruptive events
Full text linkDisruptive events, such as natural disasters, social movements or pandemics, can severely impact public transport demand. The relevance of studying the impacts of these events on public transport has been widely recognised in the literature, focusing on the investigation of disruption mitigation, delay management, vulnerability and resilience. Much less attention, however, has been given to understanding passengers’ responses amid these events. As a consequence, several gaps in this research area are yet to be addressed. These include a narrow scope in the modelling of passengers’ behavioural responses amid disruptive events, the lack of understanding of the role of individual-level factors in those responses (e.g. socio-demographics, attitudes and trip characteristics) and an insufficient examination of passive data sources for aggregate and disaggregate-level analysis (ranging from smart card to more emerging data sources such as aggregate mobility indices). This motivates this research, whose aim is to enhance the understanding of public transport demand during disruptive events. The research conducted here is temporally framed between 2019 and 2022, a period of worldwide high mobility disturbances caused by the COVID-19 pandemic. This period represents a unique opportunity to address existing research gaps in the analysis of disruptive events and public transport demand by leveraging recent literature and data sources. It is demonstrated in this research that passengers’ adaptations are more complex than the current ‘trip reduction’ approach adopted in the literature. In this regard, this thesis adds to the body of existing knowledge by identifying and modelling passengers’ mobility profiles and departure time choices during disruptive events. This research also supports using passive data sources such as smart card data and emerging aggregated mobility indices to analyse public transport demand change amid disruptive events. In particular, by addressing some of the existing challenges of these data sources, their potential to be employed for a broader range of events has been revealed in this research. This research also highlights the role of passengers’ associated characteristics on distinctive behavioural responses adopted during disruptive events, recognising a strong presence of inequality. These findings suggest that, regarding disruptive events, public transport agencies and operators should especially focus on the needs of the more vulnerable population segments, who showed fewer opportunities to mitigate the impacts of disruptive events through travel behavioural adaptation. Finally, the findings generated in this thesis can be used to improve the understanding of how passengers adapt their mobility patterns during external disruptions and, therefore, be used by policymakers to act accordingly amid future disruptive events
Microscale mobile domains in supported lipid membranes for a more dynamic and accessible model system
No full textThis thesis presents an optimized method for generating large, mobile lipid domains in supported lipid bilayers (SLBs), visible under standard fluorescence microscopy. By systematically studying the effects of ionic conditions such as PBS and Mg²⁺, hydrodynamic decoupling of domains was achieved, enhancing their mobility. Photo-oxidation effects on unsaturated lipids were characterized and harnessed to manipulate membrane composition and phase behaviour. Advanced imaging techniques like FLIM and a custom domain-tracking tool enabled detailed analysis of domain dynamics. This work provides a robust model system for studying membrane biophysics and protein-lipid interactions
Exploring Men’s Red and Processed Meat Consumption in the UK to Produce a Behavioural Portrait and Propose Interventions to Reduce Consumption
Full text linkTo limit global greenhouse gas emissions and keep global warming below 1.5 degrees Celsius, the target for UK meat reduction has been set at 35% by 2030. To maximise co-benefits to human health, this reduction should focus on red and processed meat (RPM), which is associated with an increased risk of multiple poor health outcomes. In the UK, men eat more RPM than women and have higher prevalence rates of many food-related chronic illnesses. This thesis aims to develop a clear behavioural picture of RPM consumption for men living in the UK and identify potential interventions to reduce this consumption.
Narrative reviews were conducted to establish the rationale and background to the thesis (Chapter 1). Then, starting with a broad lens, a systematic review was undertaken to capture global evidence on factors influencing men’s RPM consumption (Chapter 2). Findings were used to steer a secondary analysis of nationally representative UK data (Chapter 3) which aimed to explore unprocessed red meat (URM) and processed meat (PM) consumption patterns, identify distinct clusters, and analyse sociodemographic characteristics and healthy dietary behaviours within and between each cluster. Study 3 aimed to expand understanding by using qualitative methodology, semi-structured interviews and a reflexive thematic analysis (Chapter 4) the context and lived experience of RPM consumption among UK men. Finally, all findings were integrated (Chapter 5) and mapped through the Behaviour Change Wheel (BCW) to identify potential intervention functions and policy categories to be used for intervention design.
Findings demonstrated men consume RPM for complex and context-dependent reasons and that unprocessed red meat (URM) and processed meat (PM) consumption link to distinctly different patterns, influencing factors, and sociodemographic characteristics. RPM is consumed for reasons of enjoyment, emotion, connection with identity, reward, and a desire to have value for money, but the underlying contexts and rationales are different for URM and PM. Beliefs about health consequences vary, are inconsistent, and are attributed separately to URM and PM. The influence of health beliefs on URM and PM consumption largely depends on the value placed on the ‘naturalness’ of food and trust in external experts, which may be linked to SES characteristics. Providing trustworthy information through communication and marketing, modelling behaviours from influential in-group figures, providing alternative meal options that men enjoy eating, and introducing fiscal measures are all potential interventions that may reduce RPM consumption for men living in the UK.
Results represent the first full behavioural picture of RPM consumption among men in the UK, including the first qualitative data specific to this dietary behaviour. Findings can be used to shape research aimed at expanding the understanding of men’s RPM consumption and to develop interventions targeting men’s dietary behaviour
Neo-Victorian Medicine: Doctors, Patients, and Clinical Spaces in Neo-Victorian Fiction, 1996-2016
Full text linkThis thesis presents an original study of the depiction of medicine in nine neo-Victorian novels published around the turn of the millennium, resituating it within key contemporary and historical socio-medical contexts. I build on existing scholarship in the fields of neo-Victorian studies, Gothic studies, and the medical humanities, to argue that the dialogue between past and present in these texts is fundamentally reciprocal, and that they communicate medical ideas, practices, and anxieties which traverse historical boundaries.
Broadly, this thesis is split into two main sections: Chapters One and Two focus on the characterisation of the ‘medical man’, a central but not defining figure of the mode; Chapters Three and Four build on this analysis to consider his relationships with patients, clinical spaces, and practices of care and healing. I examine four interconnected themes through four corresponding theoretical frameworks: masculinity and modernity through theories of degeneration; medical violence and anatomical procurement through legislation; epidemics and contagious illness through phenomenology; and 'madness' through the patient narrative. These distinct thematic and theoretical interests have been selected for their enduring, or recurring, significance between the nineteenth-century settings of these novels, and their readerly reception in the late-twentieth/early-twenty-first.
Highlighting these dual temporal influences, I look both at how modern ideas around medicine are transposed onto our reimaginations of the past, and to the enduring mythologies which have surrounded medical practice from the Victorian era into the twenty-first century. In highlighting such parallels, I am concerned the implications of this recurring theme for conventional narratives of social and scientific progress, and what this reveals about continuing trends in clinical practice. I aim to move beyond an existing critical understanding of neo-Victorian medicine as primarily symbolic of social and cultural concerns; rather, I focus on its continual resurrection in neo-Victorian fiction as a manifestation of contemporary anxieties specifically relating to medicine, health, and illness. Overall, this thesis presents an interdisciplinary and cross-temporal perspective on the, as yet under-analysed, subject of neo-Victorian medicine, evaluating the social, literary, and clinical significance of its continual reoccurrence in popular culture
Characterising North Atlantic Eddy Driven Jet Variability
Full text linkThe eddy-driven jet (EDJ) over the North Atlantic drives variability in weather and climate over Europe, yet its characterisation has relied on zonally averaged diagnostics that mask its full spatio-temporal complexity. This thesis develops and applies a novel two-dimensional object-based framework to extract key EDJ features such as the latitude, strength, and tilt measured using the daily 850hPa zonal wind fields. The object method shows a unimodal climatologtical distribution of EDJ latitude, in contrast to the trimodal distribution found for the conventional Jet Latitude Index (JLI). The difference is shown to be partly due to the poor performance of the JLI when the jet is weak, broad, tilted or split.
Using this new framework, I demonstrate robust links between EDJ configurations and large-scale modes of atmospheric variability: southerly, weak, and positively tilted jets coincide with negative NAO/East-Atlantic phases and enhanced surface blocking; conversely, northerly, strong, and negatively tilted jets coincide with positive NAO conditions and zonal flow. Using data from the seasonal forecasting model GloSea5, I show that models have skill in predicting the winter EDJ latitude but have no skill for the EDJ tilt and strength. The skillful forecasts for the EDJ latitude exhibit a weak signal-to-noise ratio comparbale to what has been found for the winter NAO.
Finally, I investigate the influence of teleconnections from ENSO, QBO, and MJO with the new methodology. El Niño favours early winter poleward, stronger, westward tilted jets, while La Niña produces the opposite shifts; easterly QBO phases promote persistent equatorward, weakened jets; and certain MJO phases modulate EDJ onset and tilt on subseasonal timescales. These results underscore the importance of multidimensional jet diagnostics for improved understanding and prediction of mid-latitude climate variability and extremes
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