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The opposite of sudden
No full textDr Gascoigne explored how gestural movement in drawing relates to constructed movement in animation. The practice-led research engaged Buddhist ideas of non-attachment to challenge production norms of control, value, and ownership. Focusing on materiality and the moving body, creative outcomes contribute new practice methodologies for drawn animation
Plasma-based strategies for biofilm control
No full textOn a fundamental level, plasma is generated when a powerful energy source is used to excite matter (e.g., gas or vapour) to a stage beyond that of gases, where the molecules constituting the original matter are fragmented and a cocktail of chemically and biologically reactive charged and unstable particles is produced. These species then react with any surface they come in contact with, be it that of a liquid, solid substrate, or membrane proteins of the living organism, the reactions promoted by catalytic activity of plasma-generated electromagnetic radiation and heat. In the area of biofilm control, these reactions can be harnessed to engineer surfaces that prevent the initial stages of biofilm formation, or to create environmental perturbations and induce metabolic, genetic and epigenetic modulations sufficient to kill bacteria that manage to attach to these surfaces. This work considers several important aspects of plasma treatment that thus far may not have received due attention -the effect of physical environment, i.e., surface topography and electrical properties of the substrate on the quality of biofilm-retarding costings, and on inactivation efficacy, biofilm removal, and recolonization potential in the case of direct plasma treatment. This work demonstrates that the properties of bioactive polymer coatings assembled from terpinene-4-ol and tea tree oil on the surface of substrata with different surface morphology under low-pressure plasma conditions differ, in some instances substantially. This difference in bioactivity arises from the non-uniform assembly of the polymer on the surfaces with features of certain dimension and distribution under plasma conditions due to the non-uniform delivery of building and etching species from the gas phase to the surface. This research also demonstrates that atmospheric pressure plasma treatment used to remove biofilms from surfaces inadvertently changes the properties of the substrata, with the nature and extent of these changes being dependent on the chemical and morphological properties of the substrata. Here, the chemistry of the surface appears to play a critical role. The significance of these changes in defining cell-surface interactions is dependent on the type of substrata, e.g., biocide eluting versus contact killing, as well as on the properties of cells and cell culture conditions. For certain combinations of material and plasma-treated media, the antimicrobial activity of the substrata is enhanced. This provides a possible path for the design of more effective systems of active materials and decontamination (maintenance) treatments based on plasmas. In addition, this work also demonstrated that in some cases, sub-lethal doses of plasma exposure on Pseudomonas aeruginosa and Staphylococcus aureus bacterial cells potentially enhances their ability to recolonise surfaces, and renders cells more resilient to subsequent plasma treatments. The response is different for cells from different species, as well as for cells grown as mixed cultures. This is an important consideration for real-life uses of plasma treatment on implants, where implant ageing through wear and corrosion, and associated pitting and cracking may provide cells with ‘safe heavens’ to evade lethal doses of plasma
Living as rotten girls: women’s affects and queer fandom in China
No full textThis thesis explores the affective life of “rotten girls,” female fans of queer masculinity and male homosocial eroticism in post-socialist Chinese patriarchy. It studies interactions among three major stakeholders in the Chinese cultural realm: the fans, the state, and commercial media enterprises. I address these interactions from the perspective of the fans, a community in which I am also a participant. This research is necessary for two reasons. First, queer fandom has become extremely popular in China and requires more scholarly scrutiny than it has received to date. Queer fan culture is increasingly commercialised, but it is also more controversial under state censorship. I explore these power dynamics by examining women’s production and consumption of queer masculinity and of male homosociality in fan videos and other media texts. Second, there is a lack of nuanced understanding of fans of queer fan culture in both media and academic discourses. Female fans of queer media texts are marginalised and pathologised in Chinese mass media while in existing scholarship, they are represented in a moral dualism of compliance/resistance. This research goes beyond these essentialised assessments of the fans’ initiatives, capturing the subtle twists and turns in the fans’ everyday (fannish) life in ways that highlight their agency.
Under an umbrella agenda of research into women’s affective lives, this thesis asks two linked sub-questions:
1) How do the women fans engage with queer representations of men in new media?
2) How do these engagements shape their identities as fans and as women in post-socialist China?
This study addresses these research questions through a transcultural affective framework, facilitated by thematic analysis of semi-structured interviews with fans, and textual analysis of multiple media materials including fan videos, mass media reports, and social media discussions in and around queer fan culture. Four dimensions of the fans’ lives stand out, namely 1) how they perceive the mainstreaming of queer fandom and debates surrounding queerbaiting; 2) how they produce and consume queer representations of men in fan videos on the Bilibili platform; 3) how they negotiate senses of identity in their everyday fan activities; and 4) how they live through multiple patriarchal norms in their new media usage.
By detailing the dynamics of these issues, this research makes several major contributions. First, this thesis puts forward the original concept of “post-socialist structure of feeling” to trace the fans’ shared, often intuitive patterns of engagement in a mainstreamed queer fandom in post-socialist China. Second, it positions Chinese queer fandom as an affective heterotopia, a place that is located simultaneously in China’s socio-cultural norms and constantly bypasses the confinements of those normative discourses. Third, it parses the features of and power relations around “soft masculinity” widely consumed in contemporary Chinese pop culture. It closely examines the particular genre of danmu (laid-over comments) fan videos, as well as the characteristics and significance of rotten girls as killjoys in China’s post-socialist patriarchal system. Together, this research presents an affective, hence dynamic scene of women’s life in Chinese queer fandom, contributing to global fan studies and queer China studies
A digital twin concept to improve travellers ‘door-to-door’ travel experience
No full textThis research project investigates the development of an advanced digital travel model that optimises travellers’ door-to-door travel experience by avoiding travel disruptions, especially for travel chains including air transport.
Digital tools and technologies available to facilitate travel are typically application and airline/ airport specific. There is not a single digital tool that a traveller can use to manage their entire travel processes. Separate travel tools focus on individual transport modes and lacking connectedness between different travel stages. A major cause of traveller frustration is unexpected disruptions that can have significant direct consequences in extended travel time and extra cost. Secondary consequences are missed business opportunities or social events. Existing travel models or tools cannot adequately forecast potential disruption nor provide support to change itinerary to avoid delay. Besides, the modern traveller demands seamless travel flow, smooth transfer, customised travel plans, flexible options, and a holistic travel experience. These needs and demands reflect the key features of door-to-door travel.
To address these gaps, a framework for door-to-door travel companion has been developed that allows travellers to choose their optimal itineraries based on, for example, time or cost. Once travel is in progress, the door-to-door travel companion monitors progress and provides a notification if there is significant deviation from the planned itinerary and a missed connection is likely. The traveller then has the option to select an alternative route or travel mode, thereby avoiding potential disruptions. This feature distinguishes the door-to-door travel companion from other travel models or digital travel tools like Google Maps.
A door-to-door travel companion prototype has been built based on this framework and validated on a number of travels by independent travellers with a mix of travel modes. The door-to-door travel companion enables travellers to positively interact with the aviation industry, and it optimises traveller experience on both long-haul and short-distance flight travel routes by avoiding disruptions. This door-to-door travel companion was developed using a digital twin concept, adopting simulation and information technology to support travel digitalisation and optimisation. Its functionality, usefulness, and practicality have been evaluated by completing a series of research activities, contributing to the finalisation of this project.
The door-to-door travel companion assists travellers to avoid missed connection in advance, satisfying travellers’ travel demands and needs. The performance of the door-to-door travel companion has been validated through tests with travellers, confirming positive satisfaction and experience. Therefore, the research on the door-to-door travel companion is meaningful since it conforms to the industry development trend and market demands, changing the way of modern traveller travel.
This research and its outcomes provide a clear guideline for improving traveller satisfaction, involving digital technology in the aviation industry’s development, and contribute to the knowledge body of the research on door-to-door travel. Therefore, the research is in demand
Development of raman spectroscopic analysis techniques to assess quality biomarkers in fish
No full textThis thesis explores the use of Raman spectroscopy for efficient and non-destructive chemical analysis of fish in aquaculture and wild capture. The research focuses on developing novel methods to measure quality parameters such as lipids, proteins, carotenoids, and histamine levels. By combining Raman spectroscopy with chemometrics, new analytical techniques are developed. The thesis demonstrates the successful measurement of fish components through the skin using spatially offset Raman spectroscopy (SORS) and quantification of carotenoids and lipids using defocused Raman spectroscopy. Surface enhanced Raman spectroscopy (SERS) is employed for histamine analysis, and SORS enables the evaluation of packaged fish quality. The methods presented in this thesis have the potential to enhance production efficiency and reduce wastage in fish and food production
Development of oxide electronics based on two-dimensional materials derived from liquid metals
No full textTransparent and flexible electronics have been integrated in our daily life in many forms of applications. The contributions of such technologies range from displays, wearables, automotive circuits, solar cells, and the list goes on. To date, several materials have been investigated to be used in a thin-film transistor (TFT), a key component enabling these applications. Among them, two-dimensional (2D) oxides possess outstanding chemical and physical properties as well as offer a wide range of bandgaps i.e., they can be studied as conductors, semiconductors, and insulators.
Semiconducting oxide materials can also be subdivided into n-type and p-type semiconductors, in which the former has electrons as a majority charge carrier while the latter relies on holes. A great body of research has been carried out to explore and study n-type oxides while very few p-type oxides have been reported. Despite challenges in the search and synthesis of high mobility p-type oxides, both n-type and p-type semiconductors are required to realise the full spectrum of functional oxide electronics. This thesis focuses on studying a novel high mobility p-type oxide, namely tellurium oxide (β-TeO2).
Aside from the general need for the development of high-quality p-type oxide materials, in recent years, 2D semiconductors have also become a key research focus. 2D materials offer various notable and outstanding characteristics including remarkable carrier mobility, optical transparency, mechanical flexibility, lateral strength, etc. Moreover, their properties can be further modified through varying the thickness and surface functionalisation. Layering different 2D materials on top of one another also leads to a heterostructure which results in hybrid properties that are not observed in each individual material.
Several approaches have been established to isolate 2D oxide materials, yet some still possess limitations in cost, time, as well as high fabrication temperature. Nonetheless, liquid metals and their alloys have now emerged as another route to produce 2D materials at relatively low temperature with simplicity. The rapid self-limiting oxidation process of liquid metals in response to exposure to an oxygen-environment, following the Cabrera-Mott model, results in the formation of an ultrathin oxide layer on the surface of molten metal. This oxide skin can be exfoliated from the parent liquid metal with ease and transferred onto a desired substrate. To date, a variety of liquid metal-based transfer techniques based on this mechanism have been developed, which led to the development of a number of 2D oxides.
This thesis employed liquid metal-based synthesis principles to further expand the 2D oxides library. The material of interest in this thesis is β-TeO2, which has been predicted based on DFT calculations to be a high mobility wide bandgap p-type semiconductor. The first technical chapter of this work reports the synthesis of 2D β-TeO2 by isolating it from a molten selenium-tellurium alloy through a specifically developed synthesis technique. The material exhibited indeed a high hole mobility which was assessed through both back-gated field-effect transistor (FET) and Hall effect measurements.
The crystal structure of ultrathin β-TeO2 was also found to be non-centrosymmetric, rendering it a potential piezoelectric material. As such, piezoresponse force microscopy (PFM) analysis was subsequently performed to broaden the versatility of β-TeO2, and the results are in a good agreement with the hypothesis. Nanosheets with three different thicknesses were analysed and exceptionally high vertical piezoresponse coefficients (d33) were observed, with the highest value being obtained from the thinnest β-TeO2 sheet.
Another interesting 2D material that has been successfully isolated using liquid metal-based techniques and which is now widely studied is 2D Ga2O3. Recently, 2D Ga2O3 derived from liquid gallium has been reported to be a promising dielectric candidate as well as being capable of protecting materials underneath the oxide layer from further fabrication steps. Therefore, the material was integrated in H-diamond MOSFETs where two layers of the material were required to fully encapsulate an active region. The results have shown that double-printed dielectric Ga2O3 worked effectively as a gate dielectric material and exhibited excellent stability. The final stage of this work investigated the fabrication of a top-gated FET utilising β-TeO2 as a semiconducting channel and Ga2O3 nanosheets as a dielectric material. Despite considerable effort being dedicated towards realising this device architecture, a functioning device has not been acquired yet. The challenges that were encountered are discussed in detail and further suggestions that may allow realising this device in future work are provided.
Overall, this thesis introduces 2D β-TeO2 as one of the first high mobility semiconducting p-type oxides and high d33 piezoelectric material. These results also emphasise the potential of liquid metal-based synthesis routes in providing opportunities to study stratified and non-stratified 2D materials. The findings of this thesis will open up new avenues for exploring β-TeO2 and other liquid metal derived 2D materials as well as their potential application in oxide electronics technologies
On-camera cataloguing and verification systems for video surveillance, and its application for law enforcement
No full textTechnological advancement and a changing cultural approach to security have led to the rapid expansion of surveillance video usage in almost all areas of modern life, including public safety and law enforcement investigations. This has resulted in the generation of enormous amounts of video data in many separate jurisdictional environments, becoming a multi-faceted problem encompassing issues such as data management, individual privacy rights, data retrieval and verification as well as transparency of process. This thesis investigates specifically the problems associated with video data produced in the law enforcement context, such as data authentication in a legal sense, integrity verification in a technical sense, and identification of video samples distributed by legal entities. It examines the perspective of Law Enforcement Agencies and develops a novel technology-based solution for addressing these requirements through a distributed audit-based system combining elements of existing protocols in a new way.
A new system to enable large scale identification and verification of video data from capture through to the conclusion of the data’s life cycle is proposed, designed, and tested in both lab and real-world environments. This work explores existing mechanisms such as digital watermarking and blockchain and evaluates their viability when implemented on the camera itself. Mechanisms are implemented on the camera and tested interacting with centralised network-based services, and tests are conducted to evaluate effectiveness of such technologies in law enforcement deployment scenarios. These tests measure scalability, detection efficiency and viability. The resultant proposals use elements of digital watermarking, signal processing, blockchain, message queuing, statistical analysis and object detection. Focus is on a system capable of being deployed in as wide an array of industry standard hardware and Video Management Systems as possible. Hardware and governance limitations are additionally factored into the proposed design.
A prototype of this new system is implemented and independently evaluated in a law enforcement environment by a government agency to determine if such an approach can contribute to addressing identified issues by delivering an adaptable, vendor neutral and effective audit mechanism appropriate to these environments. As such, investigation specific deployment scenarios are considered including real time streaming, store and retrieve deployments and body worn video systems. This evaluation is conducted within real world conditions and the feedback provided contributes towards answering a series of industry focused research questions
Structural investigations on rare earth oxides & scandates under extreme conditions of pressure and temperature
No full textRare Earth elements and their oxides have been of vast interest due to their strategic importance and extensive applicability. However, the successful implementation of these materials can be ensured only when their stability under different experimental conditions is established. This is because, many of the applications of such materials involve their operation under extreme thermodynamic conditions such as temperature and pressure or even under hostile chemical environments, high radiations exposure, high electric and magnetic fields, chemical bonding related wear and abrasion etc. It is well known that changes in pressure or temperature, may result in changes to the microstructure or even structural phase changes, all of which would directly alter their properties. The current work, therefore, focuses on understanding the influence of externally applied pressures or temperatures on the structural stability of rare earth sesquioxides and rare earth scandates.
The research presented in this thesis involves the synthesis of rare earth scandates using the solid-state method, their characterization as well as comprehensive study of the structural behavior of rare earth sesquioxides and rare earth scandates under extreme thermodynamic conditions of pressure and temperature. The investigations were carried out on three rare earth sesquioxides namely Eu2O3, Lu2O3 and Tm2O3 and rare earth scandates DyScO3 and GdScO3. The materials were characterized using a suite of material characterization tools including Raman spectroscopy, X-ray diffraction, Scanning electron microscopy and Energy dispersive X-ray spectroscopy. The high-pressure effects were investigated using high energy synchrotron X-ray diffraction and Raman spectroscopy studies. External pressure was applied on the samples using the Mao-Bell type diamond anvil cell (DAC). The effect of the nanocrystalline nature on the phase transition pressure as well as bulk modulus were studied using Raman spectroscopy. The mode Grüneisen parameters were estimated from high pressure Raman studies. While scandates exhibited good structural stability under pressure, the rare earth oxides transformed to either monoclinic or hexagonal phases. The anharmonic behavior of these materials at low temperatures was studied using the variations in the phonon modes using liquid nitrogen from 80 to 440 K. Phonon softening as well as broadening of the Raman modes were observed with an increase in temperature from 80K onwards for most of the materials. Further, values of the explicit as well as implicit anharmonicity were also calculated. The three-phonon decay process was found to be predominating and anharmonic contributions were significantly higher than lattice contributions to the total anharmonic behavior. The effect of temperature variation on the Phonon lifetime was also explored. Further, Tm2O3 also demonstrated asymmetric phonon line shapes which are investigated and found to be occurring due to a weak Fano-interference effect.
Before carrying out any measurement, calibration of the instrument being used is one of the most important aspects to ensure reliability of measurements. Preliminary work on Raman metrology, a recent and highly upcoming metrological area, was carried out. Raman metrology involves various aspects of Raman spectrometer calibration, resolution, intensity correction, effect of laser source wavelength etc. In the present work, the spectrometer calibration in the full spectral range of 100-3500 cm-1 was investigated. The various materials/chemicals as mentioned in ASTM guidelines have been used as calibrants and subsequent studies have been carried out. The spectral range was divided into low, middle, and high wavenumber ranges and the effects of calibration in each wavenumber range were studied. Also, the importance of right choice of calibrant has been highlighted with a need to ensure linearity in the spectrometer motors
Machine learning method for radio frequency identification
No full textThe increasing interest in exploring robust transmitter authentication methods to enhance digital communication security has led to the emergence of physical layer authentication, a technique leveraging the intrinsic characteristics of a device to generate its fingerprints. This research investigates the feasibility of employing RF fingerprinting, as a physical layer authentication technique, in combination with deep learning algorithms to achieve transmitter device authentication. It proposes a transform technique called density trace plot (DTP) to efficiently exploit device-identifiable fingerprints resulting from physical layer imperfections. Notably, DTP operates directly on the raw received in-phase/quadrature signal, requiring no demodulation or decoding.
However, authentication relying solely on deep learning is susceptible to authentication attacks from malicious adversaries. Given that a trained deep learning classifier, or any other classification machine learning model in general, always tries to map the input into one of the known classes, it is not equipped with the capability to detect malicious input. In response to this vulnerability, this research takes an additional step by incorporating radio frequency (RF) fingerprinting for spoof detection. Specifically, the study assesses the effectiveness of various adversarial neural networks (ANNs), including the variational autoencoder (VAE) and the generative adversarial network (GAN), in detecting spoofing attempts. This evaluation encompasses both simulated investigations and experimental testing.
This thesis goes on to propose a framework for achieving rogue transmitter detection and legitimate device authentication for chirp modulation, particularly for LoRa applications. Considering that LoRa utilizes chirp modulation, which differs from other popular modulation schemes, it is essential to validate the framework's feasibility in LoRa system separately. Specifically, the continuous wavelet transform (CWT) is identified as a suitable technique for extracting fingerprints from LoRa signals. Once again, CNNs and GANs are leveraged to detect spoofing and authenticate transmitters
How social media is used as a disclosure medium during a crisis: a study of social media disclosures and practices before and during the COVID-19 pandemic
No full textThis study examined the use of voluntary disclosure on social media to understand the strategic response to COVID-19 and examined the influential factors and institutional pressures organisations faced when disclosing on social media. The study adopted a two-phase qualitative approach. Phase one used content analysis to understand voluntary disclosures by international organisations on social media. Phase two comprised semi-structured interviews with individuals involved in the decision-making process related to social media to better understand the pressures faced when disclosing on these platforms. The two phases provided evidence to understand how and why social media was used for making voluntary disclosures prior to, and during, COVID-19. Content analysis findings indicated that organisations utilised social media to make disclosures that contained decision-relevant information, but rarely disclosed anything negative in nature. Content analysis during the COVID-19 pandemic revealed a decrease in posts at the early stage of the pandemic. Subsequently there were major changes in disclosure, driven by less advertising, and an increase in social disclosures. Interviews noted evidence of institutional forces influencing the content and timing of social media disclosure, and evidence of strategic responses to institutional pressures were found. Acquiescence was the most common strategic response noted, but instances of compromise, avoidance, and defiance were also noted. This study adds to published literature on institutional theory by linking social media disclosure during COVID-19 to institutional pressures. The strategic tactics used can inform the development of guidelines and policy on the use of social media during a crisis. The findings could assist accounting educators and future professional accountants to unlock the potential of social media to facilitate dialogic accounting and extend the practice of accounting to support the management of future crises