27716 research outputs found
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Simplified overhead line equipment for railway mainline applications: system design, materials, and fault prediction
No full textOverhead Line Equipment (OLE) is widely used to electrify railways due to low
environmental impacts and higher operational speeds, compared to diesel-powered trains. Electrifying railway mainlines can pose financial challenges - many local, regional and diversionary lines remain unelectrified or partly electrified such as Sheffield-Manchester.
This research explores feasibility of the Simplified Catenary, i.e. a trolley wire modified with additional support structures near masts for low-speed, low-usage, branch, local and
diversionary lines with up to 150 kph speed. This work is the first in-depth analysis of such
simple OLE on dynamic performance since 1990.
An overhead line dynamic model was created through the Finite Element Method, and
validated against test track data from which the validated model exhibited versatility
adequate for exploring various designs of the Simplified Catenary numerically.
Parametric studies were performed considering the contact wire stiffness variation, contact force, and axial loads in contact wires. Results revealed potential benefits of using physical springs at registration arms as suspension, and of using stitch wires placed towards midspan.
This work invented a new assessment metric named ‘Design Score’ considering the current collection quality, and mechanical failures including wear, arcing, tensile failure, and fatigue. Geometric optimisation was performed using the Design Score as an objective function and Surrogate Optimisation algorithm from which some optimised Simplified Catenary was found to be operational at higher than 150 kph in compliance with EN50367.
Despite being optimised, the Simplified Catenary exhibited weaknesses in the contact force spikes – peaks (mechanical wear) and drop-offs (arcing) – near masts when pantographs experienced steep gradients. SOLARC2 (Sheffield Overhead Line Arcing 2) was designed and built in this work to assess such localised damage which helped understand their importance and suggest means of mitigation through the Oxygen Free Copper.
This research has explored the feasibility of the Simplified Catenary in mainlines through a
combination of numerical and experimental works as an exploratory step paving the way for further investigations on its potential in practice. The next step might involve incorporating more realistic operational scenarios in the model such as with gradient, or scaled tests
Finding their place: the hidden work and experiences of Indian travelling ayahs 1870 to 1947
No full textMost British families in India employed ayahs to care for children and attend to the memsahib. This thesis centralises the experiences of Indian travelling ayahs – a historically overlooked group who accompanied families on journeys to and from India – from 1870 till 1947. By examining how gender, class, and race shaped their experiences, this study offers novel insights into these itinerant female workers. It argues that ayahs occupied a liminal space that carried across all phases of their employment, marked primarily through the demarcation of physical space.
Memsahibs used “othering” practices to highlight distinctions both between ayahs and their white counterparts, however, these efforts were not always fully effective, creating a hybrid space for ayahs to navigate. The thesis shows how the social and spatial hierarchies that shaped ayahs’ treatment in India were replicated on the voyage, in the metropole, and their return. Within these boundaries, ayahs not only occupied assigned spaces but also created ones where they felt belonging.
This thesis links the experiences of travelling ayahs to discussions on empire, female domestic labour, itinerant work, transnational mobility, migration, and colonial perceptions of the gendered “other”, shedding light on the broader political dynamics of belonging within the British Empire. It does so by examining how the ayahs’ liminal status influenced their employment conditions across these domains through notions of citizenship as well as socio-spatial practices that were used to include and exclude. This thesis explores the ways ayahs situated themselves through each stage of their employment journey and managed their approaches to (non-)belonging within British colonial society. By doing so, it aims to bridge the gap between their vital work and their limited visibility in historical accounts
High-Frequency Phenomena in Inverter-Fed AC Machines: Bearing Currents and AC Winding Losses
No full textExploring the Relationship Between Oral Health and Well-being: A Qualitative Approach to Conceptualisation and Measurement
No full textBackground
The shift toward a psychosocial model of oral health emphasises the need for a more comprehensive approach to understanding its broader implications, where the ultimate aim is to enhance well-being. Well-being includes both hedonic (pleasure, satisfaction) and eudaimonic (purpose, meaning) aspects. Oral health impacts daily life, and its effect on oral health-related quality of life is well documented. This impact overlaps with hedonic well-being, although the exact nature and extent of this relationship require further clarification. However, much less is known about how oral health affects eudaimonic well-being.
Aim
This thesis investigates the relationship between oral health and well-being.
Methods
This study employed a multi-method approach to investigate the oral health-well-being relationship. Part A conducted a literature review, and a 7-year scoping review examining well-being conceptualisation in dental research. Part B performed narrative and framework analyses of interviews with 20 UK denture wearers (11 males, 9 females; aged 22-86 years), analysing tooth loss experiences through hedonic and eudaimonic perspectives to develop a novel oral health-related well-being measurement tool. The tool was refined through pretesting with 8 participants.
Results
The scoping review revealed limited and inconclusive evidence, with most studies suggesting weak or no association between oral health and well-being. However, in this thesis participants’ narratives highlighted the integration of oral health challenges into daily life, uncovering four key themes: socioeconomic inequality, masking oral functioning, accepting vulnerability and fear of social judgement. These themes demonstrated the multifaceted nature of oral health’s impact on personal, social and emotional realities. Mapping participant interviews onto well-being domains revealed heterogeneous experiences, with hedonic impacts ranging from none to severe disruption and eudaimonic impacts, both explicit and contextual.
Conclusion
This study highlights the ongoing, complex and unique impact of oral health on well-being, illustrating how subjective experiences are shaped by personal, societal and contextual factors. To address this a draft measurement tool to measure oral health’s impact on subjective well-being was developed and pre-tested
Novel Memory Machines for Traction Application
No full textHigh overall efficiency and wide constant power speed range (CPSR) enabled by flux regulation (FR) capability of a variable flux memory (VFM) machine make it a promising candidate for electric vehicles (EV) applications. This thesis focuses on novel asymmetric rotor topologies of VFM machines with hybrid permanent magnets (PMs), comprising both constant PMs (CPMs, e.g., NdFeB magnets) and variable PMs (VPMs, e.g., Alnico magnets). The synergy of magnetic-field-shifting (MFS) and FR effects are exploited, with particular emphasis on improving torque density and FR range.
Five existing symmetrical V-type-based VFM machines are optimized and analyzed. Their electromagnetic performance is compared to establish guidelines for the proposed novel topologies. The results indicate that the iron layers between CPMs and VPMs are crucial to the PM interaction effect, thereby influencing both torque and FR capabilities. A relatively wider iron layer can effectively enhance FR capability, with only an acceptable reduction in torque.
Five novel asymmetric VFM machine topologies, incorporating both asymmetric PM arrangements and asymmetric rotor core structures, are proposed and investigated. The electromagnetic performance under both flux-enhancing and flux-weakening magnetization states, including open-circuit characteristics, torque and torque components, CPSR and efficiency maps, magnetization characteristics, and unintentional demagnetization withstand capability, are analyzed and compared with those of the existing benchmark machines employing the same stator, rotor diameter, stack length, and PM volume. The comparison confirms that the asymmetric designs can enhance torque through MFS effect and by mitigating the demagnetization cross-coupling effect of CPMs on VPMs. Furthermore, the asymmetric designs can improve FR capability and thereby increase overall efficiency by enlarging the volume of VPM. All proposed topologies are fabricated and tested for validation.
Although the investigation is conducted on small-scale machines, the design guidelines for VFM machines can been established from this thesis, and the proposed topologies are considered promising candidates for EV applications
"The outdoors has opened her world up." - Exploring the experiences of children and young people with Profound and Multiple Learning Disabilities who access nature spaces and outdoor learning.
Get PDFOutdoor learning is incorporated into the curriculum of many educational settings, supported by research highlighting numerous benefits this can have for some children and young people (CYP) (Coates & Pimlott-Wilson, 2019; Hussein, 2017a). However, there is currently little understanding of the experience and potential impact of the outdoors for CYP with Profound and Multiple Learning Disabilities (PMLD).
Multisensory experiences have been identified to be a crucial element in the development and wellbeing of CYP with PMLD (Grace, 2018). Separate research identifies the outdoors as spaces in which multisensory experiences can be naturally accessed (Hart, 2003). However, there is again a lack of research investigating the capacity of outdoor environments to create multisensory experiences for CYP with PMLD.
This study aims to add to this understanding by exploring the experiences of CYP with PMLD accessing outdoor spaces. Through a social constructionist approach, ethnographic participant observations were utilised within one Forest School and one Sensory Garden accessed by CYP with PMLD. Interpretations of the experience were developed in collaboration with practitioners who knew the CYP well. Three semi-structured interviews were also conducted with practitioners who facilitate access to outdoor learning for CYP with PMLD.
Field notes and transcripts were analysed using Reflexive Thematic Analysis. Themes highlighted several aspects of the outdoor experience for CYP with PMLD; these include it being a relational space that supports equality and agency, whilst also enabling benefits such as improved communication, engagement, movement, and pain/healthcare management. Multisensory experiences can be accessed outdoors through natural resources, and are felt to be more meaningful than those experienced indoors. The outdoors is also perceived to be a space that CYP with PMLD enjoy being in, helping to change a culture of marginalisation and exclusion. Implications for practitioners, Educational Psychologists, and systemic change are explored, alongside suggestions for future research
Reference ≠ Endorsement / Archives, Intertextuality and Identity
No full textABSTRACT
REFERENCE ≠ ENDORSEMENT / ARCHIVES, INTERTEXTUALITY AND IDENTITY
This project explores archival poetics, absence and identity, expansively redefining the archival by extending conventional notions [a repository of documents] to embrace ‘theoretical archives’ which, I argue, include literary genres, ‘state apparatuses’[1], language and mass culture. The critical thesis interrogates works by Maggie Nelson, Ann Carson, Susan Howe, Claudia Rankine and Jeff Hilson, explaining why these authors treat the archival with suspicion, questioning the validity of its truth claims. Informed by thinking which includes Andrea Brady, Judith Butler, Charles Knight, Jacques Derrida, Kate Eichhorn, Audre Lorde, Marjorie Perloff, M NourbeSe Philip and Denise Riley, it examines the archival in terms of specific problematics: documentation as gendered, structurally racist and ‘governmental space’[2], controlled by a plutocratic elite. Giving equal weight to creative and source texts highlights the emotional and ethical work in the authors’ reshaping of original materials, uncovering a reframing of content to create a living archive populated with those previously un-, under- or misrepresented. My poetry collection Reference ≠ Endorsement complements the cultural work done by the five authors in widening the scope of what constitutes archival practice, positing an alternative archive through six sequences exploring domestic objects – ‘Bread’, ‘Candles’, ‘Bookshelves’, ‘Plates’, ‘Bedding’ and ‘Dining Table’ – interwoven with reflective mini-essays. Mining quotidian items from fabrics and furniture to instruction manuals and product packaging, it discovers among breadcrumbs and wax drips, tableware and nylon sheets the significance of the everyday in documenting our society and the dislocated selves consistently denied by ‘official’ apparatuses. Both elements aim to extend the thinking about poetry’s ability to challenge how and what we document and create new possibilities for the representation [re-presentation] of selves, expanding on discussions about the relevance of archive in works by Nelson, Carson, Howe, Rankine and Hilson, and offering another creative voice advocating for a more blended, inclusive, organic approach.
[1] Louis Althusser, ‘Ideology and Ideological State Apparatuses (Notes towards an Investigation), marxists.org https://www.csun.edu/~snk1966/Lous%20Althusser%20Ideology%20and%20Ideological%20State%20Apparatuses.pdf [accessed 15 November 2022].
[2] Ana Baeza Ruiz, ‘Museums, archives and gender’, Museum History Journal, 11.2 (October 2018), 174-187 (p. 175) https://doi.org/10.1080/19369816.2018.1529268
"I'd say that sliding-in is a good technique, but…”: An interpretative phenomenological analysis (IPA) exploring the parental lived experiences of supporting the facilitation of the sliding-in technique as a school-based intervention for their child with selective mutism (SM).
Get PDFBackground:
Selective Mutism (SM) is an anxiety-related psychopathology that impacts an individual’s ability to verbally communicate in particular social circumstances, despite communicating in others. Although having a growing research basis, in comparison to other developmental neurodiverse disorders (e.g. ASD) it is still limited, constraining understanding and the ability to identify and appropriately support those with SM. Existing research exploring interventions focuses largely on clinical settings which adopt quantitative methodology and as such gaps exist regarding the use of qualitative methodology which explore lived experiences of interventions for those directly involved.
Methods/ participants:
This research adopts a critical realist stance and employs Interpretative Phenomenological Analysis to explore parents’ lived experiences in supporting the implementation of the Sliding-in Technique as a school-based intervention for their child with SM. A total of five participants, all mothers within the UK, were interviewed using semi-structured interviews.
Analysis/findings:
Individual Personal Experiential Themes were identified for each participant, before exploration of patterns across accounts, led to the development of four group experiential themes. These GETs – the complex demands, perils of progression, the need for resilience and perseverance, and navigating the wider systemic obstacles –captured the tumultuous experiences parents faced while supporting the facilitation of the SiT. Despite these challenges, parents also recognised the meaningful progress their child made, highlighting its potential benefits when appropriately supported.
These GETs were then examined in relation to the research questions and existing literature and theory, with particular focus upon the impact on parental identity and motivation with specific link to the stress and coping model. These findings reveal nuanced insights into the SiT and highlight the need for clear guidance, consistent school collaboration, and enhanced emotional support for parents involved in school-based interventions for SM. Strengths and criticisms as well as implications and suggestions for future research are also discussed
Exploring the Lived Experiences of Volunteers and Peer Volunteers in Healthcare
No full textPart One: Literature Review
Peer support involves individuals with similar lived experience supporting those less advanced in their recovery. These roles provide valued contributions to healthcare. However, summaries of research so far have not attended to the experiences of voluntary peer support. This review aimed to identify current research on peer volunteers. Searches via four databases revealed 15 studies; 11 were analysed using ‘thematic synthesis’ and four were described using ‘narrative synthesis’. Four themes emerged around peer volunteers’ experiences, motivations, role benefits and challenges. Results highlighted the perspective change and personal growth peer volunteers experience, and the challenges faced around forming relationships and managing demand. Volunteering enabled flexibility and occupational purpose. Thus, the peer volunteer role requires clearer definition, to enhance role clarity and future research, and improved support structures informed by clinical psychology.
Part Two: Empirical Study
Research illustrates how volunteers in mental health care in the United Kingdom (UK) provide invaluable support for people with complex mental health needs. They are a helpful resource for professional healthcare systems who have limited finances, and volunteers form part of UK healthcare planning. Understanding the experiences of these volunteers is important to enhance the sustainability of this support. Seven volunteers working with people with complex mental health needs were interviewed by the researcher. Data were analysed using ‘interpretative phenomenological analysis’ and four themes emerged. Volunteers found it hard managing distress and felt relied upon by professional services. Some volunteers managed their wellbeing through sharing amongst those within their organisation, they also turned to family and friends. Volunteers’ sense of personal growth and community outweighed the negatives, however, if this changed, they would consider leaving. This research highlighted the need for personalised support, enhanced organisational understanding of wellbeing needs, and for professional services to maintain awareness of voluntary sector needs during healthcare planning
An initial investigation into the effects of facial feminisation surgery on the voice
Get PDFTransfeminine people may choose to undergo facial feminisation surgery: an umbrella term covering a range of procedures that aim to alter the appearance of facial features, thereby potentially affecting characteristics of the vocal tract. However, effects of facial feminisation surgery on the voice are relatively understudied. This means that little information is available to people considering undergoing these procedures, about the potential impact on their voice. Such information is of particular relevance to people who use their voice professionally, such as singers. Previous work on the vocal effects of other facial surgeries also neglects to acknowledge the variety of factors that scholars in linguistics, and in particular sociolinguistics, have shown to affect the voice. This thesis presents an analysis of the effects of facial feminisation surgery on a transfeminine professional singer through a single case study. This task is approached from three different angles. First, the acoustic changes in the participant's voice are identified, through an acoustic analysis of speech and singing data collected from her before and after surgery. Then, the results of an experiment which aimed to identify the extent to which other people could perceive a change in her voice following the surgery are presented. Finally, the participant's own perception of the effects that the surgery had on her voice are explored, through a thematic analysis of longitudinal interview data. The results of the acoustic analysis and perceptual experiment suggest that facial feminisation surgery can have an impact on the voice, and the qualitative analysis suggests this may not only be as a result of the altered characteristics of the vocal tract, but also as a result of the altered social context. This research, then, provides an argument for including sociolinguistic methods in analysis of the impact of surgery on the voice
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