Impact of Precipitation on Millimetre Wave Fixed Links and Mobile Measurement

Millimetre wave communication stands at the forefront of technological innovation, underpinning the development of fifth-generation and subsequent communication networks. Despite its promise, the propagation characteristic of millimetre wave radio links is significantly compromised by rain attenuation, an important factor during link budget calculations. This thesis undertakes a comprehensive investigation into the impact of precipitation on mmWave fixed links and mobile measurements, combining empirical weather data analysis with advanced channel sounding techniques to unravel the dynamics between rainfall and signal attenuation. Central to this research is the deployment of a PWS100 laser disdrometer, a high-resolution meteorological instrument, to capture annual rainfall statistics encompassing intensity, duration, and drop size distribution (DSD). Complementing this, an advanced channel sounder operating at 25.84 GHz (K-band) and 77.52 GHz (E-band) was implemented to measure real-time signal attenuation across a 35-meter terrestrial link. These datasets enable an examination of how raindrop microphysics such as size, velocity, and the interaction with electromagnetic waves at mmWave frequencies. This thesis evaluates established DSD models, including the Marshall-Palmer exponential model, log-normal distribution, and gamma distribution, to assess their fidelity in representing observed rainfall patterns in the Durham region, UK. While the Marshall-Palmer model offers simplicity, its limitations in capturing small-droplet dominance (<1.5 mm) under stratiform rain conditions are highlighted. On the other hand, the gamma distribution demonstrates superior adaptability to diverse rain regimes, accommodating both the skewed droplet populations of convective storms and the narrower spectra of prolonged stratiform events. This finding underscores the necessity of region-specific DSD model calibration, particularly in temperate climates characterized by mixed precipitation types. This thesis encompasses annual statistics of rain events, focusing on intensity, duration, and drop size distribution. This thesis employs various distribution models, including the Marshall and Palmer, log-normal, and gamma distribution models, to fit the collected DSD data and evaluate their suitability for representing rainfall patterns. A key finding of this thesis is the significant role of the wet antenna effect on short communication links and the importance of selecting appropriate scattering methods for the calculation of rain attenuation. The study reveals that the ITU-530 model may not be entirely suitable for short links and that a combination of Mie and Rayleigh scattering methods provides more accurate predictions for millimetre wave frequencies. Overall, this research contributes to a better understanding of the complex interactions between rain and millimetre wave signals, offering valuable insights for the development of robust communication systems capable of operating efficiently under various weather conditions. The results of this research has also led to two journal publications and serval conference papers

North Atlantic Climate Reconstruction during a Warm Event from the Last Glacial Revealed through Geochemical Analysis of a Scottish Flowstone.

Dansgaard-Oeschger (DO) warm events were interstadial intervals during the last glacial period characterised by abrupt increases in Northern Hemisphere temperature above background glacial conditions, followed by a gradual return to a stadial state. The mechanisms driving these rapid warming events, their spatial extent, and their influence on global climate cycles remain a focus of current research. Developing a clearer understanding of the triggers and controls of past climate states is critical for improving interpretations of contemporary forcing mechanisms and their cascading impacts on climate variability. This research presents new evidence for DO-12 warming at higher latitudes than previously recognised, based on a new flowstone chronology from Scotland. This chronology aligns well with SIOC19, supporting its adoption as the dominant chronology for the last glacial period. A novel method for reconstructing palaeotemperature and hydrological variability is introduced, derived from the temperature dependency of DMg and the degree of Prior Calcite Precipitation (PCP) occurring within the flowstone analogue. The reconstructed temperature range is notably large, with one possible explanation being the presence of an alternative subarctic climate regime in Scotland during DO-12. Spectral analysis of NAO-band cycles identifies a potential dampened meridional temperature gradient and stronger subtropical forcing during DO-12, attributed to northwards shifts in key Atlantic climate mechanisms. Overall, the results of this study contribute to a refined understanding of DO-12, its timing and spatial influence, the behaviour of the NAO under abrupt warming, and the resultant impacts on European climate. More broadly, this research enhances knowledge of climate cycle dynamics and the thresholds and cascade effects associated with rapid forcing changes, providing new insight into how these processes manifested during the last glacial period

Framing Charles Fellows's Lycian Collection in the British Museum: Geopolitics and Cultural Identities in the 19th Century

This PhD dissertation investigates the framing of Lycia in the 19th century, with particular attention to the collection and reception of the Lycian antiquities in the British Museum. The analysis begins with a historical contextualisation of the period, focusing first on how Charles Fellows, a middle-class gentleman from a mercantile family, endeavoured to establish authority in antiquarianism by utilising his discoveries in Lycia and offering his services to the Trustees of the British Museum in collecting antiquities for the Museum. This requires a comprehensive understanding of Victorian Britain, during which the middle class was gradually finding a place in society through reforms such as the 1832 Reform Act and the expansion of educational and professional opportunities. Yet, it was still not fully accepted in elite and aristocratic circles. The analysis then turns to the process of acquiring a firman (an imperial decree) from the Ottomans, which permitted the collection of the Lycian antiquities. This study contextualises the firman within the broader geopolitics of the Ottoman Mediterranean, thus also discussing the dynamics of Anglo-Ottoman relations in the first half of the 19th century. The analysis demonstrates how British influence was effective at the Ottoman court, relying on colonial leverage and the deterrent power of the Royal Navy. This section also raises the question of why the Ottomans allowed Britain to remove a substantial number of antiquities from Lycia, and how they themselves framed antiquities within their imperial territory in the broader context of Franco-British competition over antiquities collecting since the beginning of the century. From this point, the study focuses on how the Lycian antiquities were collected through two military-backed expeditions between 1841–1842 and 1843–1844. In these expeditions, the Royal Navy not only transported the antiquities from the region but also excavated and dismantled them. Fellows was a key figure in these operations, superintending activities in the field. This section explores the role of collecting Lycian antiquities in the transition from early antiquarian methods to proto-archaeological practices, considering their impact on the value and integrity of the monuments. Once the antiquities arrived at the British Museum, new debates emerged concerning their display. From its founding in 1759 until the arrival of the Lycian collection, the Museum had followed an exhibition doctrine that prioritised picturesque ideals, aiming to present antiquities in an aesthetic manner while showcasing their Hellenic features. This approach was shaped by Britain’s appropriation of Classical Greek civilisation, in cultural competition with France, which—by contrast—focused on Roman heritage under Napoleon. The Lycian antiquities, with their Near Eastern and local iconographic elements, did not fit neatly into this model. This dissertation investigates how the Museum framed these antiquities and examines Fellows’s role in pushing the institution to shift its approach from an aesthetic to a more ‘scientific’ one, prioritising historical context over the beau idéal in display. The final part of the dissertation explores how the exhibition doctrine of the British Museum evolved towards a perceived scientific approach based on constructing a ‘Great Chain of Art’, following Winckelmann. It examines the context of the Lycian antiquities, considering whether they were seen as a link in that chain or relegated to the periphery. It also discusses the dismantling of their dedicated gallery in light of shifting attitudes in museums and archaeology towards the end of the century

Exploring Early Childhood Teachers’ Occupational Well-Being Experiences within Professional Learning Communities: A Mixed-Methods Study in Mainland China

Background and Aim Professional Learning Communities (PLCs) hold significant potential in promoting the occupational well-being (OWB) of early childhood educators. OWB experiences encompass not only individual professional skills but also the relationships and organisational support available within PLCs. Despite this holistic approach, the literature revealed a significant lack of interdisciplinary theoretical frameworks and mixed-methodological research to investigate teachers’ experiences of OWB within PLCs in mainland China, particularly within early childhood settings. Specifically, this study aimed to first examine the correlation between PLCs and OWB. It also focused on how different PLC practices shaped early childhood teachers’ experiences of OWB, with the goal of informing the conceptualisation and implementation of diverse PLCs that enhance their OWB. Design and Methods Grounded in pragmatist ontology, this thesis employed an exploratory sequential mixed-methods approach: a survey followed by in-depth interviews (Quan→QUAL). The literature review advocated for a holistic approach to OWB, viewing it as a multi-dimensional phenomenon, including philosophical, physiological, psychosocial, and social-cultural aspects. Spaces of Well-being Theory (SoWT) was utilised to theorise the multi-dimensional relationship between PLCs and OWB, implicating that PLCs can serve as integrated spaces to enhance teachers’ holistic OWB. The survey employed a sample of 772 early childhood educators in urban Chengdu to examine the prevalence, variability, and correlations between PLCs and OWB. Survey data were analysed using descriptive statistics, Pearson correlation, and hierarchical regression analysis. The interview method conducted four focus groups with sixteen teachers and nine one-on-one interviews featuring two principals and seven teachers, reflecting diverse demographic characteristics. The thematic analysis of the interview data was used to examine teachers’ and principals’ perceived factors of PLCs that impact teachers’ OWB. Meanwhile, ideal-type analysis was employed to compare the similarities and differences among the previously identified factors within PLCs, thereby guiding the conceptualisation and operationalisation of different PLC types that can enhance teachers’ OWB. Findings This thesis has sought a practically applicable holistic conceptualisation of early childhood educators’ OWB in Chinese context, to elucidate the implications for preschools in the conceptualisation and operationalisation of a PLC culture approach. The survey results revealed a significant positive multi-dimensional relationship between PLCs and preschool teachers’ OWB to address research question one. The subsequent interview results redefined OWB from a multi-dimensional conceptulisation to a more entangled and dynamic manner to answer research question two. The interview methods further identified seven key themes (perceived factors) that shape their OWB: collegial support, unity of purpose, collaborative leadership, relationships, holistic professional development, recognition of teachers as agents, and supportive services. The thesis then synthesised and integrated these seven themes into three ideal-type PLCs: the Autonomous PLC, the Structured PLC, and the Sustainable PLC. Specifically, three ideal-type PLCs, viewed as assemblages of individual, relational and community practices, were identified as having the potential to enhance teachers’ holistic OWB in response to research question three. Ultimately, by integrating these mixed-methodological results, this thesis proposed that the research agenda on OWB should be redefined to adopt a comprehensive and holistic PLC framework synergistically that shapes teachers’ OWB in a holistic and dynamic way

Density-dependent clock spectroscopy in arbitrary arrays of mesoscopic 88Sr ensembles

For frequency metrology experiments, the fractional uncertainty is a key figure of merit: generating correlations between atoms allows this value to improve up to linearly with the number of atoms being interrogated. This has been demonstrated elsewhere using long-range Rydberg interactions in arrays of single strontium atoms and ensembles of caesium atoms. In our experiment, we are working towards demonstrating spin squeezing long-range Rydberg interactions to generate entanglement between strontium atoms in mesoscopic (N < 5) ensembles, trapped in clock-magic arbitrary tweezer arrays. We are interested in investigating how the fractional uncertainty of spin-squeezed clock measurements varies with atom number, in the case that tweezer sites are not restricted to containing a single atom at most. We hope to determine the optimum average number of atoms per site within the Rydberg blockade radius as a function of number of sites. This thesis presents progress towards this goal, which has been made in two ways. First, we have developed a novel technique for loading vertically large (100 micron) tweezer arrays with uniform and linearly-varying distributions of atom numbers in as fast as 20 milliseconds. We are able to load individual sites with average populations of between one and ten atoms, and show variations in atom number of up to a factor of two between sites in the array. We outline a theoretical model which successfully predicts our experimental results. Additionally, we show the first measurement of the 5s2 1S0 → 5s5p 3P0 clock transition in our experiment. We present experimental measurements of this transition, investigating how the linewidth and linecentre of the measured frequency spectrum varies with trap depth, atom temperature, probe beam intensity, and atomic density. We consider theoretical models of the clock transition based on the motional states of atoms in a tweezer and on collisional effects, and use these to study the effects of motional dephasing on the measured spectrum in our experiment. With these results in hand, we look ahead to the future of our experiment

Determinants of Export Performance in the Digital Age

This thesis encompasses a dual-phase investigation into the dynamics of digitalization on export performance (EP), synthesizing insights from a meta-analysis and an empirical study to present an integrated research trajectory. Given that empirical findings on digitalization and EP have been inconclusive, the thesis includes a meta-analytic review to synthesize the empirical results reported in 106 independent samples involving 62,082 respondents across nearly 30 countries. Study 1 clarifies the direct impact of digitalization on EP by synthesizing previous research and testing this relationship empirically. Furthermore, it investigates digitalization types, contextual moderators, and method moderators affecting the impact of digitalization on EP. Study 1 finds (1) digitalization’s positive and significant effect on EP, (2) the impact of digitalization on EP is also subject to different moderators, including digitalization type (i.e., digital capabilities), contextual factors (i.e., institutions, export experience, development of the region, and industry), and method factors (i.e., back translation and strategy measurement). Building upon the meta-analytic review, Study 2 employs longitudinal data from Chinese listed firms to clarify the effect of digital capital (DC) on export intensity. Firms may have the resources to invest in DC; however, these investments’ effectiveness in generating export gains may be hindered by the complexity of their diverse business activities and entrenched organizational structures. This study explore DC’s potential risks in international market in detailed. Findings indicate that (1) DC’s costs overshadow its benefits in improving export intensity, (2) DC can be materialized when the firm’s digital orientation is in place, and (3) DC further reduces export intensity when the informal institutional distance is great. The findings offer novel evidence on how DC helps achieve sustainable competitive advantages in global markets. Practically, the upfront costs and organizational integration challenges signify that the greater the value of the DC investment, the more arduous its realization; the advantages derived from DC can vary, contingent upon strategic orientation and the institutional differences between home and foreign markets

Phenomenology and Human Rights: Experiencing the Self and Other as a Human

The purpose of this thesis is to sketch out a phenomenological account relevant to the theory of human rights. In contrast to orthodox approaches which conceptualise human rights as universal norms or legal provisions which exist ‘out there’ in the objective normative or legal space – to adopt a phenomenological approach to human rights is to recognise the ways that human rights are grounded at the experiential level. Thus, this thesis advances the position that being human is, first and foremost, something that is lived. And that for one to accept that they possess rights by virtue of being human—that defining feature that makes a right a human right—the humanness to which these rights attach cannot be an abstract category, but a meaningful part of their engagement with the self, other, and the world. Within this frame, this thesis is directed towards describing these spaces where human rights are experienced as meaningful and, additionally, identifying the necessary conditions for being able to take up these spaces of meaning. More specifically, this thesis adopts the implementation of human rights by the United Nations (UN) in peace formation as a limit case to examine the pre-reflective conditions for the experience of human rights. Putting classical and contemporary phenomenological literature in conversation with International Human Rights Law, UN policy documents, and human rights literature the thesis defines the embodied, intersubjective, and normative conditions for being able to experience the self and other as human rights holders. The thesis demonstrates an original contribution to knowledge by, first, adopting a phenomenological method or approach to law, and to human rights in particular. And second, by describing the pre-reflective conditions for being able to take up human rights as a way of experiencing the self and other

Strain Sensors Fabricated From Conductive Polymer Composites

Strain sensors are vital tools for ensuring the safety, performance, and efficiency of a wide range of systems and structures. There is a need for low cost yet highly sensitive strain sensors, as this is not available in the current commercial market. Conductive Polymer Composites (CPC) have the potential to fulfil this requirement due to their good processability, cost-effectiveness and tunable electrical properties. However, despite significant progress in recent years, there are still areas of CPC-based strain gauges which require further research before they can be used for practical applications. This thesis investigates carbon black and flexible epoxy resin (CB/epoxy) composites for use as strain sensors. The CB/epoxy composites are fabricated using a method which is low cost and easily scalable, and during environmental testing found to have a Temperature Coefficient of Resistance just three times the magnitude of traditional metallic strain sensors. The CB/epoxy composites are tested under cyclic strain and calculated to have a Gauge Factor (GF) up to eight times that of typical metallic strain gauges. Thin-film metallic strain gauges are also fabricated, analysed and tested under cyclic strain to provide a reference against conventional strain gauge technology. A design of a Rig for testing strain gauges under cyclic strain is also presented. A model for the electrical properties of the CPCs under strain is developed in order to give insight into the microscopic mechanisms that determine GF, offering a valuable potential tool for optimising CPC compositions to achieve enhanced performance. Currently few simulations exist for modelling the piezoresistive properties of CPCs. This thesis not only validates the potential of CPCs as a viable alternative to conventional strain gauges, but also lays the groundwork for further innovation in the design of highly-sensitive, cost-effective strain sensors

The Organisation of Ceramic Production in China from the Tang to the Ming Dynasties

The aim of this thesis is to use archaeological evidence to investigate the changing organisation of ceramic production in China from the Tang to the Ming dynasties (7th to 17th centuries). To do this the research applies statistical methods and GIS-based analysis to a data set from published sources of 2,379 production sites, located in major ceramic-producing areas, including Henan, Zhejiang, Fujian, and Jiangxi provinces, as well as 259 workshops identified at 97 sites across China. The thesis thus proposes a detailed outline of the organisation of production from the regional to the site level. At the regional level, the study explores the distribution of Ceramic Manufacturing Sites, the formation of Regional Production Centres, and the selection of product types, and how environmental and socio-economic factors influenced regional production patterns. The findings reveal that southern China generally exhibited a more dynamic pattern of regional development than the north, with socio-economic factors such as transport accessibility, labour availability, and market demand playing an increasingly significant role in shaping production landscapes. At the site level, the spatial arrangement of facilities within workshops reveals two distinct Workshop Types, each reflecting different levels of labour specialisation. The distribution of kilns and workshops indicates three Organisation Models, representing a spectrum from small-scale cooperation to highly specialised, site-wide collaboration. A general trajectory towards larger-scale and more specialised production is observed. This research presents the first large-scale quantitative synthesis of this topic, supported by GIS visualisation. It sheds light on long-term developmental patterns in regional production, labour organisation, and specialisation within the Chinese ceramic industry, offering new insights into the evolving structure of ceramic production

The role of the R-SNARE VAMP714 in Arabidopsis under salt stress

PIN-FORMED (PIN) proteins mediate the polar transport of auxin and require vesicle trafficking for their localisation and abundance at the plasma membrane. The work described in this thesis investigates the hypothesised role of the PIN trafficking component VAMP714, an R-SNARE, in these processes under salt stress, a stress with known auxin-mediated effects on root development. Salt stress induced VAMP714 transcription and altered its protein localisation from membrane-associated vesicles to diffuse cytosolic pools. At the same time, auxin responses became restricted to the root cap and PIN polarity was progressively lost. Native-promoter overexpression of VAMP714 maintained root elongation and restricted lateral root proliferation under salinity, whereas constitutive overexpression and knockout lines did not, indicating dosage sensitivity. Tolerance depended on polar auxin transport. Protein–protein interaction assays identified CTL1 as a partner of VAMP714 at trans-Golgi and early endosomal compartments. CTL1 was required for VAMP714 distribution and for PIN1, but not for PIN2, polarity. Salt stress induced CTL1 expression in roots, and exogenous choline modified a root-specific CTL1–VAMP714 regulatory loop, suggesting a lipid–SNARE module controlling auxin-carrier trafficking. Transcriptome analysis of vamp714 mutants revealed early changes in redox and vesicle trafficking genes, with CYP96A12 emerging as a candidate regulator. Protein interaction networks highlighted AP-3, SNAP29, SYP23, and MEMB11 as dynamic partners. ROS assays showed enhanced H₂O₂ accumulation in mutants, with compensatory catalase activity, indicating a role for VAMP714 in ROS compartmentalisation. Additionally, VAMP714 may be involved in, or associated with, the SOS-mediated response to salt stress under the conditions examined in this study. Ionomic analysis showed that salt increased Na⁺ concentrations and destabilised K⁺ and Ca²⁺ homeostasis in both wild type and mutants. Auxin treatments did not restore ionic balance but elevated Ca²⁺ independently of VAMP714. Inhibition of YUCCA-mediated auxin biosynthesis impaired ionic regulation in a VAMP714-dependent manner, while exogenous Ca²⁺ partially rescued growth through a parallel pathway. Together, these findings establish VAMP714 as a stress-inducible trafficking regulator that safeguards PIN polarity, shapes redox dynamics, and connects auxin signalling with SOS-dependent ion homeostasis during early salt adaptation