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Measurement of the vector boson production cross sections at √s = 13.6 TeV with the ATLAS detector
No full textThe measurement of the inclusive W and Z boson production cross sections, and their ratios, are presented using 29 fb of pp collision data at a centre of mass energy of √s = 13.6 TeV, collected by the ATLAS detector at the Large Hadron Collider (LHC). The measured fiducial cross sections for W → ℓν, W → ℓν and Z → ℓℓ boson production are 4250 ± 150 pb, 3310 ± 120 pb, and 744 ± 20 pb, respectively, where the total uncertainties on the fiducial cross sections are reported. The ratios of top-antitop quark pair to W boson fiducial cross sections are also presented. These measurements are compared to Standard Model predictions calculated at next-to-next-to-leading order in the strong coupling, next-to-next-to-logarithmic accuracy and next-to-leading-order electroweak accuracy, where good agreement is found between the measurements and predictions. The large cross sections of the W and Z bosons, coupled with the clean final states from their leptonic decays, allow excellent experimental precision to be achieved in their measurements.
The upgrade of the ATLAS detector, undertaken in preparation for the third LHC data-taking period currently underway, has led to the improvement of various sub-components of the detector, including the Level-1 Calorimeter Trigger, which now has access to higher granularity information from the electromagnetic calorimeter. A novel set of energy corrections applied to the Level-1 Calorimeter Trigger as a result of this upgrade are also presented in this thesis, which contribute to the increased efficiency of single electron triggers for the ATLAS detector during the third LHC data-taking period
Innovations for the prevention of ocular surface scarring
Get PDFBackground Corneal scarring from various diseases is a leading cause of blindness globally and considered a priority by the World Health Organisation. Microbial keratitis (MK) is the commonest cause, often associated with regionally distinctive risk factors such as trauma in agricultural workplaces in lower- and middle-income countries versus ocular surface disease in upper- and middle-income countries. MK’s impact on working-age people means the burden of disease is vast considering it impacts the productivity. There are no approved medical therapies to prevent or reverse corneal scarring, and the only sight restoring options involve corneal transplantation or implantation, which necessitate access to specialised eye-care infrastructure and long-term healthcare service engagement. As such, there is an unmet need for non-invasive and easily accessible treatments for MK.
Aims
To investigate a novel mechanism through which decorin inhibits fibrosis in corneal fibroblasts in vitro; horizon scanning for other approved or developmental therapies for corneal scarring; to conduct a human clinical trial of decorin to prevent corneal scarring in patients with MK. The COVID-19 pandemic considerably delayed the development of this intervention, therefore additional aims were added to determine the impact of the pandemic on the project. These oriented understanding the UK public’s perception and health seeking behaviours with regards to eye symptoms in the pandemic, and finally understanding the impact of the pandemic on MK patients attending a tertiary eye care centre.
Methods A mixed methods study including a systematic scoping review, an in vitro investigation of decorin’s mechanism, a survey of public perceptions, a clinical cohort study and an early phase clinical trial. Results Eye health was a primary concern for the UK population who demonstrated proportionality of health seeking behaviour in response to eye symptoms of varying severity. The severity of MK during the pandemic was found to be no different compared to pre-pandemic times. No approved treatment for
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corneal fibrosis exists. Decorin is one such candidate which is imminently due to enter human clinical trials, with the potential to change the corneal fibrosis landscape. Decorin did not induce or inhibit autophagy in primary human corneal fibroblasts however the results helped to generate novel hypotheses for further investigations. Conclusions Although some of decorin’s mechanisms of action are yet to be elucidated, understanding the significant mechanistic checkpoints in corneal fibrosis are key, thus mechanistic studies have been incorporated into the clinical trial. Well-designed clinical trial outcome measures are required to generate robust evidence for the adoption of novel therapeutics that have the potential to change lives around the world. The public were reportedly apprehensive about volunteering for eye research, therefore researchers must be proactive in reassuring patients.
Impact of COVID on proposed thesis
The COVID-19 pandemic considerably impacted the implementation of the trial, which remains indefinitely delayed. Moreover, the university laboratories were closed for several months shutting down any in vitro work. Finally, I was seconded onto the wards to deal with patients of the pandemic. Therefore, additional project aims were required to determine the impact of the pandemic on the trial, ophthalmic conditions and research. The first new objective was therefore to understand the UK public’s perception of eye symptoms and health seeking behaviours with regards to eye symptoms in the pandemic, as well as their willingness to volunteer for research. The second was to determine the impact of the pandemic on MK patients’ clinical outcomes at a tertiary eye care centre
An approach for monetisation of social impacts accruing from rural roads
Get PDFThis PhD thesis is about finding the best methodology to be used in attaching value to social benefits accruing from rural roads through Monetisation of social benefits and costs. This PhD thesis specifically discusses the valuation of social benefits in monetary terms. The monetization of social benefits may be used in prioritizing maintenance of rural roads in low-income countries a process currently not taken care of by many available valuation methodologies. The closest of these is the Road Economic Decision Model (RED), a World Bank methodology which considers low volume roads but not rural roads with traffic volumes less than 50 vehicles per day. The thesis consists of literature review on the methodology techniques, proposed methodology for carrying out the research, the case study to assess the implementation of the proposed methodology and a discussion on the findings as well as the recommendations for further research. The available literature indicates that Sub-Saharan Africa has approximately 700,000 kilometres of rural roads, with half of them in poor condition. These rural roads however are characterized by poor maintenance regimes, low funding and in many instances limited management. Despite inadequate maintenance, rural roads contribute significantly to the economic and social development of the areas they traverse as well as provision of access to markets and amenities such as schools, health centers, religious centers, tourism centers and farmlands. Despite rural roads being drivers of development in the communities they serve, decision makers are reluctant to allocate adequate funding for the improvement and maintenance.
The literature also shows that there is no dedicated monetizing methodology for social benefits accruing from rural roads, however there are a number of techniques in use for other sectors such as environment, water and agriculture. In lieu of this, there is need to develop a methodology which can be used to monetize the social benefit from rural roads. Based on the theory of change process, the outcomes are assessed, and the associated impacts as well as the social return on investments (SROI) ratio are calculated. The SROI ration measures the value of the benefits or costs in line with the investment in monetary terms. To demonstrate the effectiveness of SROI technique, a case study in Kamuli district in Uganda was adopted, field work carried out using survey tools and the respective data collected and collated for analysis.
Results for all ten roads surveyed indicated positive correlation in the figures obtained through SROI calculations. The results provided proof that SROI can be used to monetise social benefits accruing from rural roads. It’s however, important to note that monetization based on SROI is not void of limitations. There is need to validate the data inputs, analysis and modelling. Valuation of social benefits should be considered as an ongoing process other than an event. Therefore, Monetisation of social benefit for a given community be carried out regularly
Tools to detect and characterise circumbinary exoplanets
Get PDFCircumbinary exoplanets, those planets orbiting around a binary star, are a fascinating class of exoplanet which, while prevalent in science fiction (e.g. LucasFilm et al. 1977), were only confirmed to exist in 2011. Circumbinary planets are particularly useful as a controlled experiment for planet formation since certain theorised planet formation mechanisms around single stars are not available to planets orbiting binaries. In this thesis I develop tools better to detect and understand circumbinary planets, and then deploy these across different stages of binary evolution and to various types of data. Chapter 1 provides an introduction to the field of exoplanet research and to circumbinary planets specifically.
Chapter 2 contains an introduction to Bayesian statistics and its use in model comparison for exoplanet detection. The various code contributions that I have made, in particular to kima are also described in Chapter 2. One contribution is the BINARIESmodel, tailored to analysis of radial velocity data of binaries and circumbinary planets. This model includes general relativistic and tidal corrections for close binaries; the apsidal precession of the binary as a free parameter; and the ability to analyse double-lined binaries which have two simultaneous radial velocity timeseries. Other contributions to kima are models to fit eclipse timing variations and Gaia astrometry.
Chapter 3 and Chapter 4 present results on main-sequence binaries. Chapter 3 is focused on double-lined binaries, which includes radial velocities confirming the detection of a circumbinary planet around TIC 172900988 and an analysis of a sample of double-lined binaries showing that new spectral disentangling methods allow us to obtain more precise and more accurate radial velocities than previously. A discussion of future circumbinary planet detections with Gaia data is also included. Chapter 4 divulges results from the BEBOP survey for circumbinary planets. Results include individual systems with planet detections and candidates, the BEBOP-3 system is highlighted. Other results from BEBOP are included, presenting the growing population of circumbinary planets. This population is compared to previous results from samples of transiting circumbinary planets.
Circumbinary planets have been claimed orbiting post main-sequence binaries, I revisit a famous example of a post common-envelope binary HW Virginis, which has claimed planets from eclipse timing variations, in Chapter 5. The eclipse timing variations are studied to test whether there are credible planetary signals in the data, and Gaia-Hipparcos astrometry is used to find marginal evidence for the existence of a planet in the system. Predictions are also made in Chapter 5 for how future Gaia data releases will allow for confirmation or refutation of many of the claimed eclipse timing variation systems like HW Vir.
Chapter 6 describes the use of apsidal precession measurements of binaries in greater detail and how such a measurement can be used to predict the presence of a circumbinary planet and glean information about its orbital configuration. I present the analysis of a rare binary brown dwarf which is found to have a retrograde apsidal precession, and show that ruling out all other possibilities it must be due to a circumbinary planet on an orbit inclined at 90 degrees to the orbital plane of the binary.
Concluding remarks are made in Chapter 7
Synthesis and characterisation of S = 1/2 kagome magnets in metal-organic frameworks
Get PDFMagnetic frustration is a phenomenon that may occur in materials when the arrangement of magnetic atoms in a structure results in competing magnetic exchange interactions. One example of this is the kagome arrangement, featuring corner sharing triangles of magnetic atoms, this motif is expected to generate magnetic frustration in cases where antiferromagnetic order is present. In this thesis, several magnetic kagome containing metal-organic frameworks were investigated. This diverse class of materials, comprised of magnetic metal nodes and organic ligands, provides the opportunity to examine the bulk magnetic behaviours that arise due to the use of distinct geometries, such as the kagome, which is anticipated to host interesting magnetic characteristics at low temperatures. In our initial investigation, we focus on a single member of the Cu(CO)(x)·2ClO family of metalorganic frameworks, where x represents a ditopic ligand such as bis(3-pyridyl)acetylene. This metal-organic framework features Cu, CO kagome layers which are coordinated by the ditopic ligands to form a three-dimensional network. Using X-ray and neutron diffraction techniques, along with magnetic susceptibility measurements, we were able to definitively characterise the crystal structure and magnetic properties of this MOF. The magnetic properties we describe were consistent with those observed in other compounds belonging to the same Cu(CO)(x)·2ClO family, where ferromagnetic and antiferromagnetic order coexist.
In our second investigation, we study the impact of eliminating covalent bonding between the kagome layers. To do this, we explore two additional systems with the formula Cu(CO)(x)·2ClO, where x represents a monodentate ligand such as methylpyridine or 2,4-bipyridine. These monodentate ligands give rise to a non-covalent, stacked arrangement of Cu, CO kagome layers, which were expected to suppress or eliminate magnetic exchange interactions between nearest neighbour kagome layers, forming a magnetic quasi-two-dimensional kagome structure. Using X-ray/neutron diffraction, heat capacity, and magnetic susceptibility measurements, we were able to confirm the existence of ferromagnetic exchange interactions within the kagome layers, with no evidence for antiferromagnetic exchange interactions between layers. Furthermore, we extend our investigation by exfoliating these three-dimensional materials to the monolayer limit, tracking success using atomic force microscopy. Our observations reveal compelling evidence for the successful exfoliation to a monolayer; however, further examination is required for the confirmation of crystallinity and magnetic activity.
In our final investigation, we explore the impact of altering intra-plane exchange pathways on magnetic exchange interactions within a kagome lattice by synthesising a two-dimensional MOF with the formula Cu(CO). This material features no inter-plane coordination and employs a distinct superexchange pathway anticipated to accommodate antiferromagnetic exchange interactions. By conducting high-resolution X-ray powder diffraction measurements, we were able to dispel contradictory findings from the literature, with our data suggesting a space group assignment. Furthermore, by examining heat capacity, magnetic susceptibility, and muon spin relaxation data, we observe no sign of a well-defined long-range ordered ground state. This suggested that this system may host an exotic magnetic ground state at low temperature, one such as the elusive quantum spin liquid state.
The overall conclusion of this research is that metal-organic framework chemistry provides an excellent experimental route to characterising physical examples of theoretically significant magnetic models
“To his finger-tips a fighting man”: toxic masculinity in fin-de-siècle imperial gothic literature
Get PDFIn our modern times, toxic masculinity has become a buzzword spouted by the media, scholars, and the woman on the street venting to her friends. Many conceive of this as a new phenomenon in which a small subset of men are regressing to cavemen mentality as a reactionary response to newfound gender ideologies that have proliferated in modern society. “To His Fingertips a Fighting Man:” Toxic Masculinity in Fin-de-Siècle Imperial Gothic Literature aims to refute this notion of toxic masculinity as a modern phenomenon by looking at its underpinnings in the late Victorian era. The rise of the New Woman, threats to British imperialism, and an increasingly visible immigrant class constituted significant concerns to white men’s traditionally unquestioned place of power at the fin de siècle. I highlight how figures of change like the New Woman and imperial subjects were demonized in literature of the period in an attempt to foster suspicion and animosity toward their growing autonomy. Through an exploration of Imperial Gothic texts, I demonstrate how divisive rhetoric was weaponized against women and people of color in order to justify their continued subjugation under patriarchal control. I also exhibit toxic masculinity as not simply limited to the extreme misogyny, racism, and violence that most people today associate with the term, but instead illustrate how discourses that patronize, dehumanize, or alienate marginalized groups are implicated in toxically masculine culture. I exhibit toxic masculinity as insidious due to the antagonistic relationships that it fosters between men within the dominant society and everyone with whom they interact. I additionally show how toxic masculinity harms men within the dominant culture by limiting them to a narrow expression of supposedly appropriate masculinity. The discursive techniques that I analyze in fin-de-siècle texts are remarkably similar to those used by toxically masculine men today, proving a consistency to these beliefs that belies the century plus difference between them
Educating ethical value and virtuous emotion through pop song lyrics
Get PDFThis thesis presents a case for acknowledging the ethical value that pop lyrics hold with philosophical seriousness and educational benefit. I acknowledge this ethical value by considering the aesthetic features of pop lyrics that carry emotion and ethical meaning. In doing so, I argue that pop lyrics engage us emotionally and are suitable tools for exploring themes of emotion and ethics. The thesis forms a conclusion that is educationally focussed with regard to the potential that pop lyrics hold for emotion education and moral education, giving example lesson plans for formal classroom settings, but also encouraging further exploration in non-formal and alternative settings.
I have situated this thesis at the intersection of the fields of philosophical aesthetics, pop studies and virtue and emotion education. This positioning had two intentions – to draw on the scholarly expertise across each discipline and to refocus that expertise onto pop lyrics; arguing for more philosophical consideration of pop as a legitimate form of mass art and literary insight, pursuing insights into pop culture and pop music studies that embrace moral and emotional perspectives and that the ethical value of pop lyrics provide valid tools for structured and meaningful emotional and moral education.
The work of Adam Bradley informed the origins of this thesis; his work on the linkages between rap music and spoken word (2009) and how we can see pop lyrics as poetry worthy of poetic analysis (2017). This work, rooted in the English literature and language discipline, but does not embrace any moral or ethical notions. Where scholars of pop music have considered the emotion contained within songs and its affect on listeners, this is often without wider application of any moral educational dimension and certainly without consideration of how pop lyrics can assist with the development of virtue literacy. Work by leading scholars of pop studies, philosophy and other narrative literature, such as Simon Frith (1988; 1998), Noël Carroll (1998; 2000) and David Carr (2005; 2023) have embraced the emotional affect that pop can have, which has laid fertile ground on which this thesis builds. This thesis builds on existing work, brings these separate disciplines together and situates itself at the intersection of aesthetics and ethics of pop music. It shows how aesthetics and emotions can and do interact in pop and showcases how and where emotional value and ethical value that lyrics can and do hold come together.
I conclude with an educational application; taking example lyrics and putting them into a lesson plan template and demonstrating how they can be used in a classroom setting as part of a formal character education provision
Development of antimicrobial metal alloys
Get PDFWith rising rates of orthopaedic implant infections and antimicrobial resistance, novel methods to combat these clinical challenges are greatly needed. This thesis focusses on producing an inherently antimicrobial material to offer a localised solution for infection prevention.
Ti-Cu alloys are investigated as potential candidates for biomedical alloys due to their evidenced antimicrobial efficacy. This thesis contributes knowledge to understanding what microstructural features drive the antimicrobial efficacy of Ti-Cu alloys and demonstrates that additive manufacturing may be used to amplify these effects.
Initially, arc melted specimen of Ti-11.5 (wt.%) Cu and Ti-33 (wt.%) Cu were manufactured and heat treated to examine the influence of microstructural refinement to fine tune antimicrobial efficacy. Larger (approximately 5 µm), rounded TixCu precipitates had increased antimicrobial efficacy, compared to nanoscale and elongated precipitates, though no specimen showed efficacy towards E. coli.
Further investigations using powder metallurgy and additive manufacturing demonstrated that processing routes markedly affect microstructure and copper ion release, enhancing antimicrobial potency. Notably, AM-fabricated alloys with only 3 wt.% Cu exhibited significant antimicrobial efficacy against both S. aureus and E. coli. Improvements in their responses to native bone cells were also prominent, with cell viability of 78 % and 51 % after 7 days for Ti-3Cu and Ti-11.5Cu respectively. However, concerns around the long-term biocompatibility of Ti-11.5Cu due to the ion release mechanism must be considered.
Finally, to address concerns around the mechanical mismatches that may lead to aseptic loosening, the potential for developing a Ti-Mo-Cu alloy was explored. Using low laser energy densities and post-processing heat treatments, successful Mo diffusion was achieved. This led to fabrication of promising alloy systems with 100 % antimicrobial efficacy. These findings underscore the importance of compositional tuning and role of heat treatments in optimising both the mechanical integrity and biological functionality of titanium alloys for advanced biomedical applications
Primary school Governor training: exploring the fitness for purpose of the content and mode of delivery in England
Get PDFIt is clear that the role of governance volunteers has grown exponentially, with levels of responsibility and accountability higher than ever before. This has contributed to a move away from the stakeholder-based model of governance seen in previous years to a skills-based one in which governing bodies actively recruit Governors based on their pre-existing skillsets. However, given the level of accountability involved in the role, the question arises as to whether these skills are in themselves adequate in preparing Governors to perform the role of Governor effectively or whether additional skills should be taught that enable them to have a better understanding of the educational landscape.
Adopting a mixed-method approach enabled the research to explore the perceptions of both Governors and senior leadership teams (SLT) with regards to the role Governor training plays in effective school governance. The aim of the research was to identify the current provision of Governor training, how this provision was perceived by both SLT and Governors in terms of quantity, quality, and its contribution to effective governance.
It was clear that whilst most Governors and SLT considered the overall quantity of provision to be ‘good’, there were concerns over the quality, with many referring to the “basic” or “generic” nature of training that they had experienced. There were calls for the quality of training to be improved and modernised. Many Governors felt that for training to be beneficial it needed to be relevant, contextualised, and utilise practical examples. However, for SLT the focus lay on ensuring training clarified boundaries and roles. One area that both Governors and SLT agreed was essential, was the importance of induction training for establishing knowledge at the very beginning of a governor’s tenure
Rereading the Qurʾān: The modern methodologies of Muḥammad Shaḥrūr and ʿAdnān al-Rifāʿī
No full textThis thesis critically examines the methodologies of two contemporary Syrian thinkers, Muḥammad Shaḥrūr and ʿAdnān al-Rifāʿī, who adopt unconventional approaches to reread the Qurʾān. It aims to lay the groundwork for a new methodological framework for engaging with it. Shaḥrūr and al-Rifāʿī challenge the authority of Islamic tradition, particularly the Ḥadīth, considering it neither divinely revealed nor a legitimate source of legislation. Both employ a multidimensional methodology that draws on language, mathematics, philosophy, among other fields, applying these disciplines to the interpretation of the Qurʾān and to demonstrating its divine origin through an analysis of both its content and structure.
The thesis evaluates the validity of their claims concerning the Islamic tradition and the Qurʾān, along with the criteria and methods they use to support these claims. It also assesses the novelty of their methodologies in rereading the Qurʾān. In light of the lack of critical studies on al-Rifāʿī’s methodology, integrating it with Shaḥrūr’s more widely recognized framework may help develop a new approach to reread the Qurʾān. To this end, the thesis adopts a composite methodology—descriptive, critical, analytical, and comparative—incorporating theological and philosophical reasoning alongside historical perspectives. It also situates their ideas within broader academic debates, including historical-critical and theological frameworks.
This thesis contributes to Islamic thought and Qurʾānic studies by redefining the criteria of al-naṣṣ al-ilāhī (divine text) - a form of waḥy- and offering a new understanding of the concept of Sunna. It also introduces new concepts, such as a reinterpretation of the term ʿarabī, and refutes several prevailing claims about the Qurʾān. Furthermore, it develops alternative frameworks to replace the traditional reliance on Ḥadīth-based disciplines—frameworks that seek both to reinterpret the Qurʾān and to affirm its divine origin through its content and structure.
The thesis concludes that Shaḥrūr’s and al-Rifāʿī’s claim—that the Ḥadīth and related disciplines (ʿilm al-nāsikh wa-l-mansūkh, ʿilm asbāb al-nuzūl, and ʿilm al-qirāʾāt) are human-made—is well founded. However, their work lacks conclusive proof of the Qurʾān’s divine nature, even though their criteria and methods provide a compelling case against it being a human construct. Notably, the novelty of their methodology lies in the parallel examination of the Qurʾān’s internal structure—such as its linguistic and mathematical composition—and its external features, including orthography and āya separators, as well as the use of a multidisciplinary lens. This approach leads to new insights into the text’s meaning and origin. The thesis proposes a new framework for rereading the Qurʾān, setting aside Islamic heritage and prioritizing its content and structure through an evolving, multidisciplinary approach
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