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Language learning experiences and the identities of adolescent Chinese heritage language learners in England
Get PDFGlobalisation has intensified population mobility worldwide, contributing to feelings of displacement and lack of belonging, particularly in migrant communities. Identity has become a focus in language education research. This study investigates how the identities of adolescent Chinese heritage language learners in England (aged 12–16) are constructed and negotiated through their learning experiences of different languages and language varieties.
Chinese heritage language learners refer to those with a family or ancestral heritage to Chinese language varieties. Identity is understood here as an understanding of his or her relationship to the world across time and space. The research addresses three research questions: (1) What are adolescent Chinese HL learners’ attitudes towards their languages and language varieties, and what may inform their attitudes? (2) How are the motivations and emotions of adolescent Chinese heritage language learners constructed and developed in the context of their heritage language learning? (3) How do adolescent Chinese HL learners negotiate their identities in the context of their languages and language varieties?
The study is informed by a social constructionist paradigm and uses a bricolage approach to the theoretical framework, drawing together concepts and theories from different disciplines, including language ideologies, Motivational Self System, and Social Identity Theory.
A qualitative methodology was adopted, involving 10 Chinese families across England, with one parent participating in each case. Each family took part in four semi-structured interviews. A drawing activity (language portraits) was conducted in the first interview to explore linguistic repertoires, emotions and identities. Interview topics included language practices, support strategies, learners’ motivation, emotions, and intergenerational dynamics. The social constraints of the Covid-19 pandemic were also considered. Thematic analysis revealed key themes including: the privilege of Mandarin Chinese over other HL varieties; English as the dominant language in England; reconsidering Chinese character writing skills; translanguaging and fluidity of adolescent Chinese HL learners’ identities.
The findings contribute to understanding the identities of adolescents in Chinese heritage families in relation to their linguistic repertoires. This study has implications and recommendations for heritage language education and family support practices in multicultural England
From Grove to Goods: A Diachronic Study of Tree Fruits and Their Value-Added Products in the Eastern Mediterranean and Armenia from 10,000 to 700 BCE
No full textThis dissertation examines the diachronic development of tree fruit processing and its role in ancient economies across the Eastern Mediterranean and Armenia (10,000–700 BCE). By integrating archaeobotanical data, processing equipment analysis and comparative ethnographic studies, it traces the transition of grapes, olives, figs, pomegranates and dates from local consumption to large-scale production of value-added commodities such as raisins, wine, vinegar and oil. The study addresses key questions on the extent of tree fruit exploitation, technological advancements, regional variations and the economic significance of these commodities.
A major contribution of this study is its interdisciplinary methodology, which integrates archaeobotanical evidence, material culture and ethnographic analogies. The use of GIS to map botanical remains enables spatial and temporal analyses of fruit exploitation, while assessments of historical processing techniques and the mechanical efficiency of pressing equipment provide insights into labour organisation, production scales, and technological choices in ancient communities. To deepen this analysis, mechanical engineering principles are applied to evaluate processing equipment in terms of usability, operational ease, efficiency, labour demands, pressure dynamics, processing time, production volume and product quality. Finally, a case study from the Urartian region introduces a novel framework for identifying absent or underrepresented production technologies, demonstrating that the lack of physical remains does not necessarily equate to an absence of industrial activity.
Findings indicate a gradual, regionally diverse transition influenced by ecological conditions, processing innovations and socio-economic factors. Early societies consumed fruits, with scant evidence of processing but by the Chalcolithic and Bronze Ages, increased archaeobotanical remains and simple installations point to early surplus production. In the Late Bronze and Iron Ages, the emergence of large-scale pressing equipment, including lever and weight presses, marked a shift toward organised, trade-oriented production. Regional disparities reveal different trajectories in fruit processing, with advanced installations yielding greater efficiency and standardisation, supporting extensive trade networks, while small-scale methods persisted in balancing subsistence needs and surplus trade. This research deepens our understanding of ancient horticultural economies, technological evolution and the socio-economic impacts of fruit processing
The Influence of Synthetic Gelatine on the Transient Loading and Response of Aluminium Panels Subjected to Blast Loading
Get PDFThis thesis has investigated the influence synthetic gelatine has on the structural response of aluminium panels from blast loading. To support this investigation, the compressive properties of synthetic gelatine in quasi-static and high-strain rate loading were characterised. Quasi-static compressive properties were determined experimentally using uniaxial compression experiments. The surface finish was found to affect the repeatability of these results, and friction was found to affect the stiffness response. Split-Hopkinson-pressure-bar experiments were conducted to explore high-strain rate loading. The experiments proved challenging at low velocities, with stress equilibrium not always being reached. The experiments found that the peak stress increased as the strain rate of the experiment increased. A numerical model was created for both these loading conditions, and good agreement was found with the experiments.
A novel experimental setup was developed using stereo-imaging to measure the effect synthetic gelatine has on the response of a clamped aluminium plate to an explosion. The addition of gelatine reduced the peak displacement and velocity of the target plate. It was also found to increase the time to peak displacement and velocity. These effects increased as the thickness of synthetic gelatine was increased. The gelatine was found to cause a lot of oscillations of the plate long after the loading had finished, lasting over 50 ms. The experimental setup was adapted to investigate the behaviour of deformable plates and synthetic gelatine in buried explosions. The plate responded later in the buried tests, but the peak transient displacement and velocity were found to be the same for a free-air and a buried charge. Showing that a shallow buried charge produces a similar effect on the target plate as the equivalent free-air charge in far-field explosions.
A simplified numerical simulation of blast-loaded hybrid gelatine/aluminium panels was developed to investigate the influence of gelatine on loading further. The model was found to correlate well with the free-air experimental data. Stresses were found to propagate across the width of the gelatine in the model, possibly causing the complex oscillations seen in the plate velocity data. This numerical model is a step toward understanding how a blast wave from an explosion propagates through synthetic gelatine
Temperature and structural effects on singlet fission and intersystem crossing in organic semiconductor systems
Get PDFIn this thesis, we investigate the fundamental mechanisms that contribute to triplet exciton generation in organic molecular systems, such as singlet fission, triplet-triplet annihilation, and intersystem crossing. We examine the effects of external conditions such as magnetic fields and temperature, as well as internal factors such as molecular structure, on exciton behaviours and triplet generation process.
We initially studied the temperature and magnetic field dependence on photoluminescence of a diF-TES-ADT singlet fission system. We showed, through magnetic field-dependent photoluminescence spectroscopy and a range of different optical and magnetic resonance spectroscopic techniques, that singlet fission to form a weakly bound triplet pair state is highly temperature-dependent in this material. Then, we investigated the photophysical properties of different tetracene derivatives in solution, as well as illustrated the mechanism of triplet formation using excitation wavelength-dependent transient absorption spectroscopy. By providing a comprehensive analysis of the excited state dynamics, we showed excitation-dependent behaviour in a newly synthesized tetracene dimer and some monomers, displaying unique characteristics, along with the detection of ultrafast intersystem crossing triplet formation.
Finally, we investigated the photophysical properties of a new synthesis macrocyclic parallel pentacene dimer. This dimer demonstrated an ultrafast intramolecular singlet fission process and selective generation of the quintet states. It also exhibits the longest room-temperature coherence time of a quintet state, to our knowledge at the time of publication, of 648ns
Exploring the correlation between conspiracy theories and vaccine intentions: Characteristics, dynamics, and strategies to generate resistance to it
Get PDFConspiracy theories are considered as one of the factors that influence vaccine propensity. Not only specific vaccine conspiracy theories, those who endorse conspiracy theories in general or having conspiracy mindsets, for instance: “The government agencies monitor all citizens” can influence vaccine evaluation. During the COVID-19 pandemic, conspiracy theories became a prominent issue, gaining a significant amount of attention from psychology and public health scholars. Numerous studies have demonstrated a significant association between conspiracy theories and vaccine hesitancy where increases in conspiracy theories correspond to higher levels of vaccine hesitancy. Why do conspiracy theories influence vaccine hesitancy? What possible factors might strengthen or weaken the correlation between variables? What are potential strategies to generate resistance to anti-vaccine conspiracy beliefs? This thesis will address these by testing specific hypotheses to explore the correlation between conspiracy theories and vaccine intentions, providing current evidence to understand the association between them. By relying on cross sectional and longitudinal data, four studies were conducted to provide evidence to explore the association between the study variables. The first study examined the confirmation bias hypotheses where anti-vaccine conspiracy beliefs were presumed as an expressive responding-an intention to accept misinformation to reinforce their pre-existing beliefs. This hypothesis suggests that those who endorse conspiracy theories may not genuinely believe in the conspiracy proposition. Unfortunately, study 1 failed to test this hypothesis due to non-significant effects of the experimental treatments. We continued to follow up this hypothesis in study 2 using the the data from the Trust in Scientists & Science-Related Populism (TISP) project initiated by Harvard University. Here, we tested the confirmation bias hypotheses from study 1 using non-experimental approaches and found that correlation between vaccine conspiracy beliefs and vaccine intentions was stronger in those who mistrust scientists. In study 3, we explored the correlation between conspiracy mentality and vaccine intentions with longitudinal panel data from the COVID-19 Psychological Research Consortium (C19PRC) project initiated by University of Sheffield, Ulster University, University College London, University of Liverpool and Royal Holloway University of London. This study extended the correlational analysis between conspiracy mentalities and vaccine intentions and found social events as the possible moderator where the correlation between conspiracy mentalities and vaccine intentions were stronger during the initial introduction of COVID-19 vaccines in December 2021. For the final study (study 4), we replicated Banas et al. (2023) to re-examine the effect of inoculation messages on anti-vaccine conspiracy attitudes. Although we failed to replicate the significant effect of the original study, this replication provided a valuable contribution for the inoculation theory
Mechanistic dissection of Vps45's function(s) using mutations underpinning Severe Congenital Neutropenia
Get PDFSevere congenital neutropenia (SCN) is a rare haematological disorder defined by a reduction in neutrophils, the white blood cells that fight infection. SCN patients are susceptible to opportunistic bacterial infections that become life-threatening. In 2013, Stepensky and colleagues identified the first mutation in the VPS45 gene associated with SCN V, these patients displayed an increase in apoptosis (programmed cell death) in their neutrophils and resistance to treatment. Most SCN patients have regular granulocyte-colony stimulating factor (G-CSF) treatment to manage symptoms, however patients with SCN V are subject to much more invasive bone marrow transplants to treat their condition. In addition to this SCN causing VPS45 mutation, 4 more have since been identified. Until this point Vps45 had been well-characterised as a membrane trafficking protein in yeast and more recently has been implicated in autophagy, whether these functions are related to SCN is unknown.
In this project I investigated how Vps45 is involved in increased apoptosis in cells using the model organism, Saccharomyces cerevisiae (budding yeast) by characterising the different roles of Vps45. Using yeast strains with VPS45 mutations analogous to the mutations identified in SCN V patients, I used three physiological assays to investigate the role of Vps45 in membrane trafficking, autophagy and apoptosis. By dissecting the roles of Vps45 in different processes in the cell I have identified a potential model for Vps45’s role in protection from apoptosis, characterising this role of Vps45 and its known interactors in different mechanisms will eventually lead to a more suitable treatment for SCN V patients
Automated Analysis of Textual Comments in Patient Reported Outcome Measures
Get PDFPatient-reported outcome measures (PROMs) are questionnaires that capture the patients' perspective on their health-related quality of life. PROMs contain open-ended questions, where they can provide free text comments on information they deem important regarding their outcomes and unmet needs. The PROMs comments are underexplored, largely due to the time and resource demands to analyse them and the current approaches’ inability to scale to large datasets and to compare outcomes across datasets. Addressing these gaps, this thesis aims to automate the analysis of PROMs comments to gain insights into the additional information provided in patients’ free text comments.
The thesis developed a novel patient-centric approach, including quantitative analysis of natural language processing (NLP) models and qualitative feedback from domain experts and patients. Two frameworks have been proposed to gain insights into patient comments from cancer PROMs datasets (prostate and colorectal cancer).
The first original framework is developed to classify free text comments in PROMs with prevalent themes in PROMs identified using a scoping review (Cancer Pathways & Services, Comorbidities, Daily Life, Physical Function, Psychological & Emotional Function, and Social Function). Weakly supervised text classification methods were adopted to label the PROMs comments. The interpretability of the models and the overall utility of the approach have been assessed with PROMs researchers and patients.
The second framework provides a novel application of large language models to summarise groups of PROMs comments. A systematic approach is proposed to generate prompts for summarising groups of PROMs comments and to automatically assess the quality of the resultant summaries. The human evaluation highlights summary features needed to facilitate meaningful analysis.
The approach of this thesis effectively assessed the success of NLP methods to analyse PROMs comments beyond technical robustness, revealing their overall impact and the broader implications for adoption
Analysis of particle deformation during impact deposition
Get PDFParticle impact is a common occurrence in numerous applications that involve handling and processing of powders. Depending on the impact details, it can have various implications for a process, e.g. it can affect the flow behaviour of powders due to kinetic energy dissipation, or influence the particle-particle and particle-substrate bonding mechanism, and consequently, the quality of the final film in coating processes such as cold spraying (CS). Thus, investigating the impact phenomenon is important for understanding and improving the efficiency of such processes. However, experimental investigation of particle impact is precarious, especially at high velocities, as the event takes place in an extremely short span of time. Therefore, numerical simulations provide a great means for the analysis of the phenomena taking place throughout impact. Discrete Element Method (DEM), Finite Element Method (FEM) and Molecular Dynamics (MD) are amongst the popular numerical methods used to date for the simulation of particle impact. However, these methods have certain limitations when dealing with the problem of impact, especially at large deformations. On the other hand, a method known as the Material Point Method (MPM) can be utilised to overcome such drawbacks. As MPM has seldom been used for the simulation of particle impact, it is adopted in the current work to carry out a comprehensive study of the impact phenomenon, especially when large deformation is concerned. Most studies on high-velocity impact processes like CS often overlook the influence of particle mechanical properties and density. Therefore, the present work considers a wide range of material properties and impact velocities to investigate their effect on the impact deformation behaviour.
To this end, MPM simulations are carried out for the impact of an elastic-perfectly plastic particle on a rigid wall. The results are analysed by focussing on variables and expressions that characterise the particle’s plastic deformation and rebound behaviour. It is observed that the plastic deformation of the particle is primarily governed by the incident kinetic energy and yield strength of the material. On the other hand, the recovery of deformation and material’s resistance to it-particularly at small deformation-are intuitively influenced not only by these factors, but also by the material’s Young’s modulus. Empirical equations are suggested for the prediction of the coefficient of restitution and the compression ratio of the particle, leveraging dimensionless groups. Subsequently, the capability of Artificial Intelligence (AI), specifically Machine Learning (ML) techniques, in identifying the underlying trends in the simulation data and refining the empirical equations is examined. Accordingly, the simulation results are introduced to a hybrid AI framework, which successfully recognises meaningful relationships, when presented with the already identified dimensionless groups. The limitations of the framework are then highlighted, and recommendations are made for further improvement. In the end, impact experiments are carried out to assess the accuracy of the numerical simulations and empirical equations. Elastic impact is first examined using elastic balls to validate the simulation predictions against experimental measurements. Elastic-plastic impact is then investigated using metal particles impacted in a custom-built impact device, with the measured compression ratio and coefficient of restitution compared to empirical predictions. Lastly, the applicability of the empirical compression ratio equation to high strain rate impacts is evaluated by depositing fine copper particles via aerosol deposition. The results confirm that the simulations accurately model the elastic impact, and the empirical equations can reasonably predict the compression ratio. However, the predicted coefficient of restitution is underestimated compared to the experimental values, though it performs better than a number of other theoretical/empirical equations. It is also found that the compression ratio at high strain rates is better predicted by a higher representative yield strength, attributed to work hardening dominating the overall deformation. The study combines numerical modelling, AI-driven analysis, and experimental validation, contributing to a deeper understanding of particle impact behaviour
Recovering teacher practices and student experiences of practical work in school science, 1944-1988
Get PDFDespite a resurgence in scholarly interest, the impact of school education in science remains under-researched. Histories of British school science have considered developments to policies and curricula but have excluded in-school events, inadvertently implying that large-scale changes were implemented smoothly.
This thesis prioritises two bodies of evidence to scrutinise in-school events in English secondary school laboratories: a collection of school apparatus from the Science Museum, and 30 oral histories from teachers and former students. Where previous accounts have failed to surface evidence of in-school activity, these sources offer insight into the distinct perspectives of teachers and former students. I present a dual narrative of both stakeholder groups’ experiences, using case studies of teachers’ handmade school equipment and former students’ frequently recalled practical work.
I examine the period between 1944 and 1988 in which secondary schooling expanded significantly, offering opportunities for creative teaching and a broad range of student experience. Throughout this period, state intervention increased as teachers’ input into curriculum and policy change reduced. This thesis will consider how large-scale changes impacted experiences within schools, and vice versa.
In this dual narrative I illustrate how teachers creatively made and adapted apparatus to gain agency, have fun, and to connect with their professional community. Never previously explored, I highlight how these practices may have influenced the demands for and approach to Nuffield Physics, as well as the consistency of this practice regardless of large-scale externally imposed changes.
Former students’ oral histories reveal the long-lasting sensory and sentimental impact of doing practical science. Impactful practical work surpassed expectations, whether routine experiments that offered responsibility and agency, or infrequent and shocking experiences. Surfacing teachers’ and students’ in-school experiences demonstrates what remains of value throughout lifetimes and thus has implications for the Science Museum as it employs its collection in the future
Nowcasting Convective Weather: Evaluation, Development and Application of Techniques
Get PDFConvective storms produce hazardous conditions that can lead to natural disasters such as flooding and landslides. Their societal and economic impacts are felt throughout the world, particularly in vulnerable tropical regions. Providing effective early warnings for such events requires accurate short-term prediction — a major challenge in meteorology, especially in the Tropics, where numerical weather prediction models have low skill. Nowcasting fills this capability gap by rapidly generating weather predictions with lead times on the scale of minutes to hours.
This thesis presents advances in convection nowcasting, including satellite-based solutions for the Tropics and the extension of traditional nowcasting techniques to flood prediction. First, traditional nowcasting tools, which are typically radar-based, are applied to the Maritime Continent – a tropical region that experiences regular convective activity – using satellite brightness temperature retrievals, a viable alternative to radar data, which is scarcely available in this region. Overall, these tools demonstrate skill in nowcasting propagating convection up to 4 hours in advance, but struggle to capture the initiation and growth of convection over mountainous regions during the afternoon period. Next, a novel satellite-based machine learning nowcasting tool, SII-NowNet, is introduced. SII-NowNet produces skilful nowcasts of convection initiation up to 2 hours in advance and convection intensification up to 3 hours in advance, over the Maritime Continent. Using Zambia as an example region, SII-NowNet shows that it can generalise well to a previously unseen tropical region without any re-training. Finally, traditional nowcasting techniques are applied to develop N-FOREWARNS, a surface water flood nowcasting tool that generates useful flood risk maps up to 3 hours in advance. N-FOREWARNS is both quantitatively verified and qualitatively assessed by expert users, demonstrating added value to existing operational capabilities.
Overall, the nowcasting developments presented in this thesis show the potential to strengthen early warning systems via improved nowcasting tools and thereby enhance resilience to hazardous weather in vulnerable communities
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