VictorJuiz/thesis huggingface dataset:
High resolution characterisation of oxidation mechanisms in polycrystalline nickel based superalloys
Keywords: Atom Probe
Oxidation
Dwell Fatigue
Oxidation Mechanisms
Alloy design
Superalloys

In order to withstand the demanding conditions experienced at the heart of modern jet turbine engines, nickel based superalloys must combine extreme strength with resistance to temperature-dependent degradation mechanisms such as oxidation and fatigue. This is increasingly becoming a priority, as operating temperatures continue to be pushed higher due to tighter fuel economy and emissions targets.
A new generation of high temperature, damage tolerant superalloys has been developed which balances all of these properties through careful control of composition. For further alloy development, the relationship between oxidation kinetics and alloy composition must be established. Two elements in particular have been focussed on – titanium and niobium. Both of these elements are vital for maintaining high temperature strength; however Ti has been experimentally shown to increase rates of oxidation, while Nb has been implicated in accelerating dwell fatigue crack growth.
In order to study these composition-property relationships, a family of near identical superalloys have been created with varying titanium/niobium ratio, and subsequently characterised. Oxidation kinetics were studied using thermogravimetric analysis, which confirmed the link between titanium and oxidation, while also creating oxide scales for further characterisation. A variety of high-resolution techniques have been used to analyse these oxide scales on the smallest scales, revealing the location of titanium – some was found dissolved in chromia oxide scales as expected – but much more was found segregated to grain boundaries within the oxide. Ion transport along these grain boundaries may explain the oxidation kinetics better than the lattice diffusion mechanism previously assumed.
A number of fatigue crack tips also underwent examination, in an attempt to shed light on the mechanism by which niobium encourages dwell fatigue. While no evidence could be found for this, a number of analysis techniques have been developed and refined to hopefully aid these efforts in future.
Mechanisms for novel multidimensional choices in prefrontal cortex
Keywords: Primate
Novel choice
Ultrasound
Grid cells
Inference
fMRI

In this thesis the cognitive and neuro-computational bases of novel value-based decision-making in non-human primates are studied. Humans routinely perform choices among options that have not previously been experienced, using value expectations derived from their component attributes. Animal studies, however, are typically performed after extensive training ensuring familiarity with the task. Here we show how Rhesus macaques can readily perform value-guided choices among novel stimuli – if their components are known. An economic analysis of subjective biases is provided. Neuroimaging and causal techniques are then used to uncover a network centred in anterior medial frontal cortex (AMFC) underlying adaptive novel decisions. A first experiment, using fMRI with a binary decision task, reveals that orbitofrontal cortex is equally modulated by value in novel and familiar choices, but in contrast AMFC and dorsolateral prefrontal cortex (dlPFC) show a markedly different pattern of responses between conditions. A second experiment, using fMRI and single option trials, reveals how AMFC and dlPFC, but no other regions, encode representations of abstract value independent from its components (reward magnitude and probability), appearing across sessions with exposure to the novel options. Additionally, a pattern of hexagonal symmetry is found in AMFC activity, indicating a grid-like encoding of two-dimensional value space. Such a code provides a mechanistic explanation of how novel options’ values may be computed. A last experiment confirms this by showing that transiently disrupting AMFC with focused transcranial ultrasound impairs the use of an integrated representation of value when novel decisions are made. Together, these experiments bridge neuroscientific studies in humans and monkeys and reveal a neural basis for novel decision-making that has not previously been investigated in either species.
Mosul and Mosilu historians of the Jalīlī era (1726-1834)
Keywords: Iraq
Jalīlī
historiography
Mosilu
Jalīlīs
Mosul
historians

This work of regional history deals with the Ottoman town of Mosul in northern Iraq at a time when it was ruled by a local dynasty of walis, the Jalīlīs. The work falls into eight chapters covering: the urban geography of Mosul and the pattern of urban growth under the Jalīlīs (suqs, religious buildings, etc.); urban society (communities, officialdom, armed forces); the nature of the Mosuli economy and the role of the town in an intricate network of trade routes linking Persia to the Mediterranean and Asia Minor to the Gulf; political life in Iraq as it developed along the major arteries of communication encircling Mosul (influence of the walis of Bagdad, power of the Arab, Kurdish and Yazīdī tribes); the urban politics of notables (rise of the Jalīlīs, the "localisation" of political combinations, etc.); cultural life in Mosul (fundamental orientations as determined by the geopolitical situation of the area, the centres of cultural life in Mosul, the main fields of cultural production); a presentation of the Mosuli historians and historical production; and finally, an investigation into Mosuli perceptions of the history of the Ottoman Empire, the political entity of which Jalīlī Mosul was - - and felt itself to be - - an integral part.
Middle-class suburban lifestyles and culture in England, 1919-1939
Keywords: life
lifestyles
class
suburban
middle-class
20th century
culture
England
middle

Between the wars, approximately three million houses were constructed by private builders, the majority for owner-occupation. Many of these houses were located in new suburban estates, catering for an expanding white-collar middle class. Alongside the growth of these new suburbs, there emerged a virulent if composite indictment of inter-war suburbia. Although the critics did not focus exclusively on suburbia, they frequently claimed that suburbia's environment and values exacerbated problems which were more widespread within society. The result, it seemed, was a life that was isolated, philistine, overly materialistic, and obsessed with status. This thesis challenges that picture. It focuses on six areas of suburban life on which the critics were particularly vocal. These areas centre on, or grow out of, suburban domestic life: the suburban environment, house interiors, the life of the housewife, the experience of mothers and children, primary education, and recreation.
The main conclusion is that contemporary criticism of suburban life was often unjustified. Although speculative builders may have covered the countryside with ugly and badly-planned estates, the inter-war suburbs satisfied both the desire for bucolic seclusion and the demand for a safe place to rear children. The much-denigrated suburban semi catered successfully for the needs of the small family, incorporating modernity and efficiency without the uncompromising symbols of modernism. The suburban housewife did not feel imprisoned within a regime of unremitting domestic drudgery; she usually accepted her role as logical and satisfactory. Far from preferring consumer goods to children, middle-class parents revealed a concern for their offspring which extended even to following expert advice that was over-rigorous and insensitive. True, some of these parents sent their children to private schools which were physically and educationally unsatisfactory. But they did so because they believed that such institutions offered the best prospects - both educational and social - for their children's future advancement. Private education was simply one element of a middle-class attachment to privatised values. Yet privatised values did not preclude gregarious activity. For middle-class suburban recreation reveals a wealth of both family-centred and communal activities, defying the pessimistic image of a demoralised and isolated people forced exclusively onto solitary and 'mechanised' amusements.
The nature of teaching and learning when using a painting as a central stimulus across the curriculum
Keywords: art education
creativity
creative and cultural learning
art
creative teaching

The study qualitatively explores why and how five UK primary schools operationalised a project that uses a painting as a central stimulus for teaching and learning across the curriculum, as promoted by the Take One Picture scheme run by the National Gallery, London. On analysis, it was found that teachers at two of the schools mainly approached Take One Picture primarily as an art project, whilst teachers at the three other schools mainly approached the scheme in a more cross-curricular way.
Using a multiple within-case analysis approach, data was collected through interviews and a questionnaire from 25 teachers to explore teachers’ understanding of the Take One Picture scheme and their expectations for undertaking a project. This data, alongside data from log journals compiled by the teachers, was used to explore the operationalisation of projects teacher-by-teacher. In addition, pupil outcomes, as perceived by the teachers and actual pupil outcomes contained in the log journals, were analysed to consider whether teachers’ expectations were borne out.
It was found that on the whole teachers planned for their expectations and these were realised in pupil outcomes. However, in some cases where teachers expressed an expectation to encourage creativity or to follow pupil interests, this was not apparent in the way they planned or in pupil outcomes. Furthermore, the nature of teaching and learning in these projects was shown to be heavily teacher-led. Also, these projects tended to be planned by teachers in the schools that took a primarily art-based approach. In contrast, projects that were more cross-curricular showed greater signs of encouraging individuality and originality from pupils. These latter projects regularly involved experiential strategies, as characterised by Dewey (1938), identified in the study as (i) encouraging individual responses from pupils beyond the parameters of practising an art technique, and (ii) making connections between the painting and other stimuli and/or known pupils’ previous learning experiences. The analysis suggests that the inclusion of experiential strategies both helps to encourage creativity (if the definition of creativity used includes the concept of originality) and increase cognitive challenge. In addition, the data shows that those teachers who worked in partnership with artistic practitioners, or had art expertise themselves, tended to plan in a more instructional, less experiential way.
Overall, the study offers a contribution to knowledge by showing that in art education some teaching and learning strategies seem more effective than others in providing opportunities for pupils to develop creative skills, and that these strategies link to high cognitive demand.
Security of mixed reality systems: authenticating users, devices, and data
Keywords: Mixed Reality
Mixed Reality Security
Cyber Security
Systems Security
Virtual Reality
Cyber-physical systems security
Computer Systems Security
Augmented Reality Security
Augmented Reality

Mixed reality devices continuously scan their environment in order to naturally blend the virtual objects with the user’s real-time view of their physical environment. Given the potential of these technologies to profoundly change how individuals interact with their environments, many of the largest technology companies are releasing their mixed reality systems and devoting significant resources towards achieving technological leadership in this field.
However, due to the recency of the first commercially available mixed reality devices and their specific interaction channels, existing research has yet to provide practical proposals to achieve many of the core security objectives. Furthermore, given that these devices continuously analyze their environment using multiple front-facing cameras, when designing secure system it becomes necessary to reassess the commonly assumed threat models.
In this thesis, we aim to bridge this gap by focusing on secure authentication on mixed reality headsets. Taking into account the stronger assumed adversary models and the interface capabilities of existing mixed reality devices, we propose methods for user and device authentication, as well as show how these devices can be used to secure one’s interactions with legacy systems.
Considering that mixed reality headsets are starting to support gaze tracking, in this thesis we propose, build a prototype and experimentally evaluate the use of reflexive eye movements as a biometric modality that is well suited as an authentication method on MR headsets. As an added benefit, the reflexiveness and predictability of one’s eye movement responses makes it possible to incorporate the biometric measurements into challenge-response protocols. This allows the system to prevent replay attacks, one of the most common attack vectors on biometrics.
Furthermore, given the many multi-user applications of mixed reality technologies that rely on direct communication between users’ devices, in this thesis we research secure and usable methods to mixed reality headsets. We propose a practical pairing protocol, implement a system prototype using two commercially available mixed reality headsets and evaluate its security and usability.
Finally, we show that front-facing cameras of mixed reality headsets can also serve as the means of securing legacy electronic systems. We therefore build and evaluate a prototype of a system that uses a trusted device with video capture and analysis capabilities to authenticate the data that the user inputs when using a potentially compromised local client to communicate with a remote server.
Measuring operational realities of security and privacy for deployed avionics
Keywords: Avionics
Aviation
Flight simulation
Wireless security

Despite being renowned as an exceptionally safety-conscious industry, aviation has been slow to address the cyber security threat. A critical point has been reached whereby systems which were designed many years ago are in wide use, but lack meaningful security measures. Meanwhile, it has become easy to acquire and use tools which enable potential attackers to listen to---and even tamper with---these systems. Like many safety-critical industries, aviation lacks the ability to rapidly redeploy systems. This creates a situation where known-vulnerable systems must be kept and, even worse, heavily relied upon.
The work in this thesis focusses on two topics: analysis of a well-established and heavily used general-purpose avionic communication system, and a first look at a method to analyse and prepare for attacks caused by a lack of security measures on avionics.
For the former, we focus on the Aircraft Communications Addressing and Reporting System (ACARS). We show that it has very few deployed security solutions, and the instances such solutions have been used are weak. As a consequence, we demonstrate the impact of the lack of meaningful confidentiality protection for non-commercial aviation actors---military, government and business aircraft. We show that even when efforts are made to protect privacy elsewhere, they stand a significant chance of leaking data via normal ACARS usage.
Moving to the cockpit, the second topic attempts to begin to address one of the current unknowns in the area of aviation cyber security - how attacks on avionic systems might affect the way the aircraft is flown. In this, we used a flight simulator to create the cockpit-based effects of attacks on three important systems. Using these, we created scenarios in which the aircraft was under attack and invited 30 Airbus A320 pilots to take part.
Whilst the current state of security and privacy in aviation is far from ideal, we believe that methods to provide security in the near- and long-term are achievable. Privacy in the near-term is somewhat harder, but steps towards it in the longer term are underway.
Cancer cell cycle modulation by metabolic gene expression and role of photoreceptor phosphodiesterase 6H in cancer cell growth
Keywords: cell cycle
cancer metabolism
phosphodiesterase

While the deregulation of cancer metabolism through oncogenic signalling, and the effect of the latter on proliferation and cell cycle control are widely studied, little is known on how metabolism in cancer cells leads to cell cycle control and progression. This project aimed to identify metabolic genes whose inhibition causes cell cycle arrest, which would allow further study of candidate genes in the context of cancer metabolism and cell proliferation. The screen was conducted with a custom siRNA library targeting metabolic genes commonly amplified in primary tumours, as well as those known to be involved in the key regulatory points of metabolic pathways.
Results show that TCA cycle, fatty acid metabolism and nucleotide metabolism are especially important during the transition into S phase, whereas enzymes of electron transport chain, glycolysis and pentose phosphate pathway are significant for the completion of both G1 and G2 phases. Among the genes whose knockdown caused G1, cone phosphodiesterase 6H (PDE6H) of the retina was selected for further study as a novel controller of cancer cell cycle and metabolism, recognised for a role in controlling retinal metabolism.
Besides causing G1 cell cycle arrest and disruption of G1/S checkpoint mechanism, PDE6H knockdown induced apoptosis and mitochondrial dysfunction. PDE6H depletion also inhibited cell proliferation and lowered basal levels of cellular metabolism. In xenograft experiments of PDE6H CRISPR/Cas9 knockout HCT116 cells we showed that PDE6H deletion slowed down tumour growth and improved animal survival. PDE6 inhibition via a drug, zaprinast, caused similar increase in tumour hypoxia and necrosis as well as an inhibition of tumour cell proliferation. Our results report PDE6H as a controller of cancer cell metabolism and proliferation, making it a potential target for therapy.
Martyrology: a critical examination of the role of theological traditions in the narrative construction of the martyr
Keywords: Latin America
Religion
Canonisation
Discipleship
Book of Revelation
Sacrifice
Imitatio Christi
Witness
Praxis
Suffering
Aquinas
El Salvador
Saints
Social Constructivism
Asceticism
Social Narratives
Martyrology
Acts of the Apostles
Radicalisation
Christian Persecution
Martyrdom
Gospel of John
Political Theology
Romero
Benedict XIV
Death
Odium Fidei

This thesis presents a socio-theological analysis of the process by which a martyr is made and presents an analytical framework for a theological analysis of martyrdom, as well as demonstrating the fruits that such analysis can bring. Building on the social constructivist view that the martyr is a narrative construct and martyrdom a particular way of imagining an individual’s death rather than an historical event, this thesis demonstrates the operation of theological conceptualisations of the meaning and significance of martyrdom, which it terms martyrologies. These martyrologies profoundly affect how the martyr is imagined and consequently the model of discipleship they represent to others. Martyrs have a unique power to validate a cause and to embody the possibility of extreme conviction and resistance in a way which can mobilise and radicalise their communities.
This thesis argues that critical analysis of these martyrologies is therefore imperative if we are to understand their role in defining the martyr and therefore shaping the way that the martyr’s community interpret and engage with their reality. Four martyrologies, rooted in the emergence of martyrdom in the early church, are presented and, through their critical examination, a methodological framework for their future analysis is exhibited and recommended. The theological ideas sustaining these martyrologies are shown to be radicalising, morally challenging, and logically and theologically incoherent. Most importantly, this thesis attends to the phenomenon of popular martyrdom, particularly prevalent in Latin America. It explains the martyrology responsible and, controversially, shows why this martyrology is in fact entirely orthodox, challenging the Church’s opposition to it. It also shows, however, that its claim that the basis for martyrdom can be a political cause makes this martyrology not only a threat to political theology, but even a potentially radicalising tool.
Connecting past and present: the archaeology of the contemporary past in the glades of Embobut, Kenya
Keywords: Forests
Landscape
Indigenous
Kenya

At its most basic, this project aims to explore the recent archaeology and history of Sengwer communities and the Embobut Forest in the Cherangani Hills, Kenya, in order to better understand how they conceptualise their ‘indigeneity’. Such work is especially relevant in Cherangani given recent attempts by Kenya’s national government to move the Sengwer from the forest within the context of the ‘National Resource Management Project’ funded by the World Bank. These evictions resulted in a legal case hinged upon the issues of conservation and ‘indigeneity’, partly due to a change in the World Bank status of the Sengwer from ‘Indigenous People’ to a ‘Vulnerable and Marginalised Group’. This alteration was rejected by the Sengwer not least because the term ‘Indigenous People’ is both a part of a much larger, international dialogue and alludes to a relationship between humans and their landscape in a way that ‘Vulnerable and Marginalised Group’ does not. Thus, the Sengwer have been attempting to re-assert their right to live in Cherangani by drawing upon a range of historical and cultural ideas that demonstrate the importance of the relationship they bear with their landscape.
Unfortunately, realising this aim has been hindered by a lack of wider intellectual interest, since no academic studies have hitherto explored the history, archaeology or ethnography of the Sengwer in any detail. As such, I have worked with the Sengwer community in order to conduct a diachronic analysis of how they have constructed their landscape and engaged with their forest environment. In turn, a more rigorous understanding of the temporality and materiality of the Embobut landscape as understood from the ground up helps contextualise what has become a complicated and contested narrative of landscape modification over the past century. Indeed, different perspectives of deforestation and conservation as gleaned from government reports and activist documents illuminates how landscape change is multifaceted, not only being caused by shifting livelihoods of the people residing there, but also the imposition of conservation boundaries by the colonial Forest Department in the early twentieth century. Ultimately, then, my work aims to bring a more materially centred approach to help better comprehend how the Embobut Forest has changed in conjunction with different perceptions, understandings and experiences of the landscape.