VictorJuiz/thesis huggingface dataset:
Motion estimation using radiofrequency scattering of a parallel transmit coil for cardiac magnetic resonance imaging at 7T

Magnetic resonance imaging (MRI) at ultra-high magnetic field strengths offers an increased signal-to-noise ratio (SNR) and has the potential to boost the MR image resolution. Cardiovascular applications remain challenging, as high-resolution image acquisitions are still too slow to capture a fast moving organ like the heart. Synchronisation of the acquisition to the heart motion is necessary to acquire an image over several consecutive heartbeats. The current gold-standard method for cardiac synchronisation is the electrocardiogram (ECG), which measures the electrical activity of the heart. Magnetohydrodynamic effects of the blood flow interfere with the ECG measurement and can affect reliable gating, which is particularly significant at higher magnetic field strengths.
The work of this thesis presents new motion estimation methods that are based on radiofrequency (RF) scattering of a parallel-transmit coil and directly assess the heart motion, independent of the electrical activity of the heart. A cardiac motion signal is derived with a high SNR and with a number of potential gating features, which have a high accuracy when compared to ECG gating. No additional motion-monitoring hardware is needed other than the commercially available pTx system. Different RF pulse designs are proposed to integrate the scattering measurements into the normal MR image acquisition to estimate cardiac and respiratory motion in real-time on the MRI scanner. The integrated cardiac-respiratory motion framework is combined with a new MR imaging acquisition strategy to acquire high-resolution, 3D images of the heart during free breathing.

Keywords: S-Matrix
Radiofrequency Scattering
Motion Estimation
Advisor: Hess, A
Robson, M
Endohedral fullerenes as standards for portable atomic clocks

Highly stable and accurate frequency sources underpin a wide range of modern technologies. For many applications, there is a need to develop clocks with low size, weight and power (SWaP). Significant effort has been expended in miniaturising existing atomic clock architectures, but the various limitations inherent to contemporary designs incentivise further exploration of novel architectures.
Here, I investigate endohedral fullerenes as possible frequency references in future portable atomic clocks. Firstly, I detail the instrumentation developed to acquire the low-field data presented in this thesis. I then show that the endohedral fullerene 15N@C60 possesses a magnetic field-insensitive "clock transition" with fclock ≈ 38.6 MHz at a field Bclock ≈ 0.8 mT. This measurement is the first observation of a clock transition in a molecular spin system at room temperature, and it enables me to estimate the stability of an fullerene-based clock. The predicted performance is very poor, and I discuss potential strategies to address this problem.
I also investigate the hyperfine coupling as a function of pressure. The measured shift (dA/dP ≈ 3.5 × 10-4 Hz Pa-1) is too small to be a useful tunable parameter with which to offset the temperature coefficient of a fullerene-based atomic clock. However, it does ensure that such a clock would be reasonably insensitive to atmospheric pressure fluctuations. Using this datum I make the first experimental estimate of the compressibility of an isolated fullerene cage.
On the basis of the research performed in this thesis, I believe that the outlook for fullerene-based frequency standards is poor. They are fundamentally limited by their low frequency clock transitions and broad linewidths relative to the atomic frequency standards used in contemporary portable atomic clocks. This is due to their small hyperfine interaction and the coupling between the electron spin and degrees of freedom that are absent in atomic systems.

Keywords: Endohedral fullerene
Electron paramagnetic resonance
Allan deviation
Atomic clock
N@C60
EPR
Frequency reference
Electron spin resonance
ESR
High-pressure EPR
Solid-state
SWaP
Magnetic resonance
Quantum
Spectrometer
Advisor: Briggs, G
Laird, E
Mol, J
Part II of the Parmenides and its reception in Metaphysics, Iota: identity and non-identity

Demonstrating that Aristotle is a careful reader of Plato whose interest does not merely lie in rejecting the ideas of his teacher is not a task that has been ignored by scholars. However, surprisingly, there has been no extensive attempt to approach Aristotle’s reception of Part II of the Parmenides in this way. One of my overall aims in this thesis is to correct this by demonstrating that Aristotle’s engagement with the first and second deductions of the Parmenides in Metaphysics, Iota 3 is sophisticated and complex. My second aim is also one that has been unattempted: to show that in both texts, we uncover important lessons for contemporary metaphysicians. My final goal is to show that my exploration of both texts has significance for our understanding of the Parmenides and Metaphysics, Iota and the study of Plato and Aristotle more generally. In achieving this, I focus on the treatment of numerical identity and non-identity in the first and second deductions of the Parmenides and Metaphysics, Iota 3.
The thesis falls into five chapters. In the first, I settle some important preliminary questions.. In the second, I uncover definitions of identity, non-identity, similarity and dissimilarity in both texts and argue that we might think they could aid contemporary proponents and opponents of a ‘strict’ Leibniz’s Law. In my third chapter, I explore whether this is in fact possible. My fourth chapter concerns two laws of identity and non-identity that seem uncontroversial but which we might worry Plato and Aristotle violate in Part II and Iota. My final chapter deals with identity and non-identity in the context of wider discussions of relativity in Plato and Aristotle. I conclude by showing that I have met all three of the overall aims of this thesis.

Advisor: Coope, U
Judson, L
Two seconds, one frame

This practice-led research explores what I have come to term ‘cruel images’, and how to treat them as object and subject through the making of art. Cruel images imply a degradation of sorts: images that represent politically degraded subjects in turn get materially degraded through mediation and passage from one medium or file type to another, which degrade the subject further by virtue of being seen, or passed over. The methodology of this research lies in handling and re-editing found archival materials in post-production, whereby knowledge is produced through an extreme closeness to the materiality of an image and the dialectics of montage. The thesis explores the notion of cruel images, in their various angles, forms, and conditions, with the aim of contributing knowledge at the threshold of looking at, or looking away from, images of violence, taking writers and image-makers of colonized contexts, such as Palestine, as historic cases in point. My quest to critically explore the critical and material grounds of the cruel image was prompted by a single shot excavated from a found obsolete Soviet film collection of hundreds of film reels in Jordan. It was a two-second shot that the Palestinian photographer and cinematographer Hani Jawharieh filmed during the aftermath of the 1967 war with Israel. The image served as a foil for analysing questions around images of violence at large, by way of handling digitized materials to question whether watching, analysing, and disseminating the archival image of the dead can help us to understand the contemporary condition of sharing, handling, and reacting to the “immaterial” image of violence today. The writing and practice components of this project inform each other. The rhythm of the writings take inspiration from the rich lexicon of the Arabic word natq—which means to utter; to speak, to pronounce, to use one’s voice when one otherwise couldn’t. The practice component, meanwhile, is a series of film works that aim to treat the afterlife of cruel images.

Advisor: Martin, D
Gardner, A
Public Private Partnerships and public law in China

Public Private Partnerships (PPPs) as one form of government contracts engaging the private sector in infrastructure development have been practised worldwide. Since 2014, PPPs were promoted by the Chinese Central Government with unprecedented strength, and booming PPP practice gives rise to a legal inquiry: how PPP contracts should be conceived in the current system of government contracts in China, which is characterised by a distinction between administrative contracts and private contracts? Contextualising PPPs in the landscape of China’s political economy, investigating policy rationales, regulation and practice of PPPs as well as examining the existing legal debate over the nature of PPP contracts in China, this Thesis argues that PPPs should be classified as administrative contracts to enhance government accountability and better achieve the public interest.

Advisor: Craig, P
Authoritarian regimes and the co-optation of Islam: Kazakhstan and Russia

National and subnational authoritarian regimes with Muslim majorities prefer to co-opt rather than repress Islam in order to bolster their legitimacy, limit bargaining partners, deter mobilization, and gather information. Authoritarian regimes also elect to co-opt other potential sources of opposition besides religion due to similar incentives. Religion, however, is a unique source of potential opposition given its high salience relative to other forms of identity. Repression or overt co-optation of the majority religious identity holds a higher potential to foster an opposition movement based on religious identity. In order to deter this threat, national and subnational regimes frequently create a separate religious institution for Islam. Kazakhstan, a national authoritarian regime, and Tatarstan, Russia, a subnational authoritarian regime, both attempt to co-opt the majority religious group, Islam, through quasi-governmental agencies. Quasi-governmental agencies reduce transparency and provide a semblance of official distance between co-optation efforts and the regime. However, the different layer of institutional structures between national and subnational authoritarian regimes spurs each type of regime to pursue different strategies. Given the regime juxtaposition between Tatarstan and Russia, Tatarstan more frequently pursues co-optation through unofficial and extra-legal means. Alternatively, a higher level of institutions does not exist in Kazakhstan. Thus, there is a higher degree of harmony between the law and policies on religion. In addition to using a quasi-governmental agency, both regimes attempt to securitize Islam by framing regime associated religious sources as the panacea to extremism and other negative influences. Muslims in Kazakhstan were more likely than Muslims in Tatarstan to report using religious sources approved by the regime. This is likely because Kazakhstan had a wider array of tools at hand to co-opt Islam. However, a majority of Muslims in neither case cited securitization narratives to justify why they chose to use governmental religious sources.

Keywords: Islam
co-optation
subnational
Kazakhstan
authoritarian regimes
Russia
religion and politics
authoritarianism
CIS
Advisor: Sasse, G
Towards practical metal-organic framework materials: Operando and in situ studies by leveraging synchrotron and neutron sources

Metal-Organic Frameworks (MOFs) are a new class of porous materials with dozens of potential future practical applications. This thesis strives to bring that future nearer by leveraging synchrotron and neutron sources to study MOFs for next generation dielectrics, catalysts and sensors. A novel approach to measuring broadband dielectric functions of pelletised MOF powders using specular reflectance Fourier Transform Infrared (FTIR) spectroscopy is developed. MIL-53(Al) is investigated as a model system, and ab initio calculations for dielectric functions of its large pore and narrow pore phases show good agreement with experimental data. Rapidly synthesised Pd@MOF composites based on the OX-1 material are developed and investigated using a combination of FTIR, inelastic neutron scattering and x-ray absorption spectroscopy. The Pd@OX-1 structure is shown as a step towards next generation heterogenous single-metal-site catalysts, where Pd atoms reside selectively on benzene rings of the linkers and are recaptured during catalytic cycles. The ZnQ@OX-1 composite is studied using in situ transmission FTIR spectroscopy to identify key vibrational modes responsible for its photo-chemical sensing of acetone, and to probe the limits of its sensitivity. It is shown that ZnQ@OX-1 is a promising competitor for the currently best performing metal oxide-based sensors. Quantum tunnelling methyl rotors inside ZIF-8 pores are used as more exotic sensors for gas molecules adsorbed into its pores. The importance of chemical interactions of N2 and Ar molecules are highlighted by shifts in neutron powder diffraction patterns, while the likely importance of specific adsorption sites is brought to bear by inelastic neutron scattering spectra, which reveal shifts in energies of the quantum tunnelling methyl rotors. The ‘gate opening’ phenomenon is reclassified as ‘gate blocking’ based on these operando experiments. Overall, this thesis develops practical MOFs and extends the toolbox for their further advancement.

Advisor: Tan, J
Impartiality in international adjudication

Impartiality is generally accepted as central to the rule of law, indispensable for legitimacy and effectiveness, necessary for legal interpretation and fundamental for fair treatment. But there are key issues that remain unresolved: What should impartiality mean in the context of international adjudication? How can one proceed to identify the principles and rules of impartiality? Why do different international courts and tribunals apply different rules and standards of impartiality?
By providing an understanding of the concept of impartiality, this thesis seeks (1) to explain the pluralism of the principles and rules of impartiality and the insufficiency of the legal norms to guarantee the full achievement of impartiality, and (2) to illustrate the relationship between the functions and characteristics of different international courts and tribunals and the principles and rules of impartiality that correspondingly apply to these courts and tribunals.
Moreover, the thesis seeks to identify the principles and rules of impartiality to be applied by international courts and tribunals when the statutes of these judicial organs do not specify the principles and rules to be applied. The thesis recognizes the inherent indeterminacy in answering this question as a result of the argumentation structures composed of induction and deduction underlying the source-based approach in international law, but nonetheless proceeds to employ analogical reasoning to clarify further the content of principles and rules of impartiality applicable to international courts and tribunals. The thesis also identifies functions and characteristics of international adjudication that can be utilised to decide what principles and rules of impartiality are applicable to different forms of international adjudication.

Advisor: Sarooshi, D
Parameterizing models of collective cell spreading

The study of how cell populations grow and spread is integral to understanding and predicting the invasion of cancer, the speed of wound repair and the robustness of embryonic development [20, 81, 96]. However, the extent to which cell populations grow and spread is governed by multiple processes, including motility, proliferation, adhesion and death, making it difficult to elucidate the relative contributions of these processes to the growth and invasion of a cell colony [106]. As such, in vitro cell biology assays are routinely used to probe the mechanisms by which cells interact, and the key processes involved in the growth and expansion of cell colonies. These in vitro assays generally involve seeding a population of cells on a two-dimensional substrate, and observing the population as the individual cells move and proliferate and the density of the monolayer increases towards confluence. A useful approach to interpret the results of these assays involves using a mathematical model that incorporates mechanistic descriptions of processes such as cell motility and proliferation. By parameterizing and validating the models using quantitative data from in vitro assays it is possible to provide quantitative insights into the mechanisms driving the growth and spreading of a cell population, and make experimentally testable predictions. However, it is not always clear how best to choose the experimental design, nor which summary statistics of the data to collect, in order to accurately and efficiently parameterize and validate models. The importance of various experimental design choices in arriving at testable predictions and outcomes are evaluated in this thesis, for a variety of models, cell types and currently employed experimental protocols. The use of inference is demonstrated for the first time in a previously developed force-based mathematical model, extended to account for proliferation.

Advisor: Simpson, M
Baker, R
A witness to pain: Samuel Beckett and post-war Francophone drama

This thesis examines how Beckett stages physical pain in his early theatre plays, arguing that Eleutheria (1947, pub. 1995), En attendant Godot/Waiting for Godot (1952/1954), Fin de partie/Endgame (1957), Happy Days/Oh les beaux jours (1961/1963), Play/Comédie (1964) and Not I/Pas moi (1972/1975) generate intensely sceptical readings of sympathetic or redemptive forms of witnessing. These plays raise questions about our capacity both to communicate our own physical suffering, and to comprehend – or in some cases even to perceive – another’s pain. They prompt us to interrogate the utopian ideas of empathetic witnessing and of the theatre auditorium as a site of intimate communion, which were popularised after World War II and which still linger in public consciousness and contemporary criticism. Bringing together Anglophone and Francophone scholarship, this project resituates Beckett’s early plays in the long aftermath of World War II in France, reading them as part of a post-war drive in Francophone literature to formulate new ways of negotiating the extreme wartime and post-war experience of witnessing others’ pain. I offer a comparison of Beckett’s plays with the work of four contemporary Francophone artists: Albert Camus, Pablo Picasso, Eugène Ionesco, and Marguerite Duras, each of whom, like Beckett, lived out World War II in France as non-native non-combatants. I explore how these plays construct a live encounter with the human body within the paradoxically intimate distance of the theatre auditorium, drawing the spectators’ own responses unsettlingly into question. This comparative examination combines close textual analysis with consideration of recorded audience responses to the staging details of specific productions, ranging from Roger Blin’s 1953 première production of En attendant Godot at the Théâtre de Babylone through to Vahid Rahbani’s unlicensed 2005 staging of Eleutheria in Tehran and Jess Thom’s 2018 staging of Not I at the Battersea Arts Centre.

Keywords: suffering
war
France
Beckett
pain
Francophone
Advisor: Jones, S
Quantitative analysis of complex materials using non-negative matrix factorisation

The properties of a material are unquestionably linked to its structure. Thus, in or- der to wholly understand, or even predict, a material’s properties we must establish a complete understanding of its structure. Developing this understanding becomes particularly challenging when a material comprises multiple components. Experi- mental measurements of complex materials are often complicated as they contain contributions from different components, and interpreting measurements of complex materials in terms of their individual components is a well established problem. This thesis concerns a newly developed multivariate analysis technique designed to break up experimental datasets and describe them in terms of a number of indi- vidual components. The algorithm at the heart of this is called Matrix Metropolis Factorisation (MMF)—it combines Metropolis Monte Carlo minimisation into a non- negative matrix factorisation algorithm to produce a robust and versatile method for decomposing experimental datasets. This thesis comprises applications of this methodology to the structural characterisation of complex materials. Active pharmaceutical ingredients (APIs) are often intentionally prepared in an amorphous form to improve drug solubility and bioavailability. Total scattering and PDF measurements have been used to study these disordered materials. I then show how MMF analysis of PDF data enables: (i) structural characterisation of the amorphous API in a complex preparation, (ii) determination of the maximum API loading level capable of inhibiting crystallisation, and (iii) identification of drug design strategies for improving stability of the amorphous form. Next, a number of mixed-metal framework materials are considered. Through MMF analysis of infrared spectroscopy data the distribution of neighbouring cations pairs is determined as a function of composition for three formate perovskite families, and Cd-doped ZIF-8. Atomistic pictures of domain formation are developed for each material which may, in principle, enable tuning of ferroelectric and sorption behaviour. Finally, I identify the existence of a locally ordered domain structure that persists above the magnetic ordering temperature of a simple cubic ferromagnet. MMF analysis of radial spin-correlation function data was used to determine regions of ferromagnetic order within a largely disordered paramagnetic phase. The systems considered each have complex structures that are governed by short- range interactions and can be described in terms of a small number of components. In each case, MMF analysis is used to identify these components, including those that cannot be measured in isolation. Fundamentally the same methodology is applied to data from different experimental techniques to probe the local structure of each system.

Keywords: Metropolis Monte Carlo
Total scattering
Pari distribution function
Non-negative matrix factorisation
Multivariate analysis
Complex materials
Advisor: Goodwin, A