VictorJuiz/thesis huggingface dataset:
Exploiting ion-charged dielectrics for high efficiency solar cell architectures

This thesis studies the production and performance of p-type inversion layer (IL) Si solar cells. IL cells use an electric field to induce an inversion layer and create a pn junction. Compared with the mainstream diffused pn junctions, the advantages of field-induced junctions include lower fabrication costs and less carrier recombination. IL cells have been studied since the 1970s. In previous work, intrinsic charge in dielectric materials has been used to induce the inversion layer. However, the charge density was not high enough to induce a sufficiently conductive junction emitter (n-type surface layer). In this thesis, a field and temperature-assisted ion migration method was used to incorporate a controllable amount of positive ionic charge into dielectric thin films and fully exploit IL cells.
The ion migration method was first used to induce an electron accumulation layer on n-type substrates. The lowest accumulation layer sheet resistance (Rsh) obtained is 950 W/sq, which is the lowest reported in the literature. A model was developed in Sentaurus TCAD to study the formation and properties of field-induced layers. The simulation results suggested that the Rsh is determined by charge density, band-tail interface state density, and illumination. With optimised charge density and interface parameters, the lowest IL Rsh that can be achieved in the dark is 1.1 kW/sq. Although such Rsh is ~7 times higher than that of typical n-type phosphorous-diffused emitters (150 W/sq), the cell performance evaluated by device simulations is not limited by the high Rsh. The simulation model comprises a field-induced emitter and a PERC-like structure at the rear. The best simulated IL cell shows an efficiency of 24.8%, comparable to the best predicted for PERC. This indicates that field-induced emitters can perform as well as P-diffused emitters.
Proof-of-concept IL cells were fabricated via laser doping, annealing, ion migration, and light-assisted electroplating. The formation and uniformity of the field-induced emitter were confirmed by taking a photocurrent map of the IL cell. The champion cell presents an efficiency of 10.8%, demonstrating that IL cells can be fabricated using the ion migration method. Although the efficiency is low, simulation results suggest that an efficiency of as high as 24.8% can be achieved with optimised processing. With low fabrication costs and high potential cell efficiencies, field-induced emitters can become competitive alternatives to P-diffused emitters in commercial applications.

Keywords: ion migration
inversion layer cells
dielectrics
charge-induced emitter
silicon solar cells
Advisor: Bonilla Osorio, R
Wilshaw, P
Panoptic dual-use management: preventing deliberate pandemics in an age of synthetic biology and artificial intelligence

Powerful new technologies can have profound global security implications. In this thesis, I investigate how advances in synthetic biology and artificial intelligence could have dual-use potential and enable the deliberate release of pandemic pathogens. I review risks from synthetic biology based on case studies on wildlife virus discovery, viral engineering for vaccine design, and viral engineering for gene therapy. For assessing impacts of artificial intelligence, I consider large language models and biodesign tools. I find that related advances can create new methods to engineer pathogens and make such capabilities increasingly accessible to non-specialists.
These risks are not well captured by existing risk mitigation measures. I argue that the management of dual-use virological research is currently defined by oversight of individual research projects. This is effective for addressing high-risk research but fails to address risks from a more diffuse set of research and technologies with dual-use potential.
To help mitigate these risks, I introduce the idea of panoptic dual-use management. Inspired by methodologies to reduce carbon emissions, panoptic dual-use management involves treating associated dual-use risks as negative externalities and creating appropriate incentives so they are accounted for in decisions between projects. I explore ways in which such incentives could be created for various stakeholders. For instance, funding bodies could use dual-use risks as a tiebreaker between projects on the brink of getting funded, a practice which would incentivise researchers to preferentially propose projects with lower dual-use risks. To realise this proposal, I sketch out a framework for assigning tiered dual-use scores to virological research.
I conclude by highlighting the importance of combining different dual-use management approaches across stakeholders and geographies to establish an effective complex of overlapping mitigation regimes.

Keywords: technology governance
biosecurity
pandemic virus
dual-use risks
artificial intelligence
pandemic prevention
dual-use dilemma
Advisor: Savulescu, J
Wilkinson, D
Relman, D
Esvelt, K
Business and contested authority in Colombia, 1996-2016

Businesses are prominent actors in areas of contested authority, yet they respond in varied ways to its challenges, from seizing expansion opportunities, negotiating with armed groups, working with state armed forces, or leaving altogether. What are the conditions that affect businesses in areas of contested authority, how do they respond, and what security outcomes do they experience? I argue protection quality – whether protection is reliable and affordable – and business power – a business’s capacity to deploy financial or political resources – are the key conditions that affect business security outcomes in areas of contested authority. Businesses respond through three pathways: they pursue accommodation by passively absorbing the costs of insecurity, they use voice to influence coercive actors to gain better protection, or they choose to exit by closing their business, seeking alternative protectors, or leaving altogether. The underlying conditions create four distinct security outcomes: coexistence, entanglement, survival, and victimisation. I present a series of cases across Antioquia and Valle del Cauca in Colombia from 1996-2016, comparing the conditions, responses and outcomes for agricultural firms, capital-intensive enterprises, neighbourhood shopkeepers, and mining companies. When protection quality and business power are high, businesses maintained a state of coexistence with coercive actors. When business power is high, yet protection quality is low, businesses experience entanglement with coercive actors. When protection quality is good, but businesses have less power, they experience survival, and when businesses have low power and poor protection, they experience victimisation. I draw from interviews with businesspeople, business association officials, journalists and observers gathered over the course of fieldwork in 2019, supplemented by newspaper articles, court documents, government data, and secondary sources.

Keywords: Conflict
Business
Contested authority
Civil war
Colombia
Advisor: Friedrichs, J
Gledhill, J
Fisher-Hartwig asymptotics and log-correlated fields in random matrix theory


This thesis is concerned with establishing and studying connections between random matrices and log-correlated fields. This is done with the help of formulae, including some newly established ones, for the asymptotics of Toeplitz, and Toeplitz+Hankel determinants with Fisher-Hartwig singularities.
In Chapter 1, we give an introduction to the mathematical objects that we are interested in. In particular we explain the relations between the characteristic polynomial of random matrices, log-correlated fields, Gaussian multiplicative chaos, the moments of moments, and Toeplitz and Toeplitz+Hankel deter- minants with Fisher-Hartwig singularities. Chapter 1 is based on joint work with Jon Keating [FK21], Tom Claeys and Jon Keating [CFK23], and Isao Sauzedde [FS22].
In Chapter 2, based on joint work with Jon Keating [FK21], we establish formulae for the asymptotics of Toeplitz, and Toeplitz+Hankel determinants with two complex conjugate pairs of merging Fisher-Hartwig singularities. We prove those formulae using Riemann-Hilbert techniques, which are heavily inspired by the ones used by Deift, Its, and Krasovsky [DIK11], and Claeys and Krasovsky [CK15].
In Chapter 3, based on joint work with Jon Keating [FK21], we complete the connection between the classical compact groups and Gaussian multiplicative chaos, by showing that analogously to the case of the unitary group first estab- lished by Webb [Web15], the characteristic polynomial of random orthogonal and symplectic matrices, when properly normalized, converges to a Gaussian multiplicative chaos measure on the unit circle.
In Chapter 4, based on joint work with Tom Claeys and Jon Keating [CFK23], we compute the asymptotics of the moments of moments of random orthogonal and symplectic matrices, which can be expressed in terms of integrals over Toeplitz+Hankel determinants. The phase transitions we observe are in stark contrast to the ones proven for the unitary group by Fahs [Fah21].
In Chapter 5, based on joint work with Isao Sauzedde [FS22], we establish convergence in Sobolev spaces, of the logarithm of the characteristic polynomial of unitary Brownian motion to the Gaussian free field on the cylinder, thus proving the dynamical analogue of the classical stationary result by Hughes, Keating and O’Connell [HKO01].

Keywords: Gaussian Multiplicative Chaos
Riemann-Hilbert Problems
Log-Correlated Fields
Toeplitz and Toeplitz+Hankel Determinants
Mathematical Physics
Fisher-Hartwig Singularities
Random Matrix Theory
Complex Analysis
Advisor: Keating, J
Ring-theoretic properties of augmented Iwasawa algebras

Let p be a prime, G be a p-adic Lie group and k be a field of characteristic p. The augmented Iwasawa algebra kG is a noncommutative algebra extending the construction of the Iwasawa algebra of a compact p-adic Lie group. In this thesis we investigate the ring-theoretic properties of augmented Iwasawa algebras.
We prove that a split-semisimple group over a p-adic field F has a coherent augmented Iwasawa algebra if and only if its root system is of rank one, and deduce that kGLn(F) is coherent precisely when n is at most two. We also characterise when certain solvable p-adic Lie groups have a coherent augmented Iwasawa algebra. When kG is a coherent ring, the category of finitely-presented smooth representations of G over k is abelian. We give a module-theoretic characterisation of the latter property, and hence give examples of p-adic Lie groups for which it fails. These results are achieved by developing the theory of augmented Iwasawa algebras in detail, including their relation to smooth and admissible representations of G.
The Iwasawa algebra of a compact p-adic Lie group is always an Auslander-Gorenstein ring. Thus finitely-generated modules over Iwasawa algebras have a canonical dimension. Let G be a compact p-adic Lie group whose Lie algebra is isomorphic to a split simple F-Lie algebra. We prove that whenever F is a non-trivial finite extension of the p-adic numbers, kG has no modules of canonical dimension one. Consequently kG has a module of canonical dimension one only if the Lie algebra of G is isomorphic to sl2(Qp). As a corollary we obtain a new upper bound on the Krull dimension of kG.
When G is an arbitrary p-adic Lie group, any smooth admissible representation V is the dual of a kG-module M, finitely-generated over the Iwasawa algebra of a compact open subgroup of G. The canonical dimension of M measures the rate of growth of invariant subspaces of V. We prove a canonical dimension-theoretic criterion for V to be a finite length representation. We deduce that the finite length smooth admissible representations of GL2(Qp) with central character are precisely those whose duals have canonical dimension at most one. Finally, let F be a non-trivial finite extension of the p-adic numbers, G = GLn(F), and V be a smooth admissible representation of G with central character. A combination of our results shows that V has finite length if its dual has canonical dimension two.

Keywords: Canonical dimension
Smooth representations
Noncommutative rings
Langlands programme
Completed group algebras
Coherent rings
p-adic Lie groups
Advisor: Ardakov, K
Passionate correction: the theory and practice of modernist revision

The early twentieth century in literature was a period of second chances. James Joyce and Virginia Woolf each spent a decade on their first novels, discarding complete drafts along the way; Henry James took three years to revise his already published work for the New York Edition. The poets fared no better. The Waste Land, Ezra Pound's first Canto, W. H. Auden's Collected Poems, and Marianne Moore's Complete Poems were all multiply rewritten.
This dissertation examines the importance of textual revision to Anglo-American modernism. I ask why modernist writers revised so laboriously, what modes of selfediting they preferred, and how they figured the process of textual genesis. Revision is not normally understood as an activity exceeding the idiosyncrasies of individuals. My work shows that it can and should be historicized as a form of cultural practice. In the first chapter, I discuss and criticize available models for theorizing revision. In subsequent chapters, I make use of methods from genetic criticism and social text editing to analyze the process of textual development from early manuscript drafts to final published editions.
The modernist practice of revision was enabled by changes in technology and the literary marketplace in the 1890s. At the same time, revision is an exemplary figure for modernism itself. By rereading a text, the revising writer pays homage to what is already there, but rewriting devalues and may even destroy the original version. This oscillating movement answers to a fundamental tension or puzzle in modernist thought between innovation and tradition, "making it new" and nostalgia for the past.
Where pre-twentieth century writers were uncertain and uneasy about the benefits of revision, modernist writers tend to portray textual change in positive terms as an inevitable process of "gradual betterment." Literary critics and editors have gladly adopted this teleology. At the same time, the most famous acts of modernist revision display a surprising pleasure in textual destruction. In chapters on Henry James, Virginia Woolf, T. S. Eliot, and W. H. Auden I explore the relationship between textual practice and early twentieth-century ideas about progress, selfhood, efficiency, and organic form.

Keywords: W. H. Auden
typewriter
modernism
T. S. Eliot
Virginia Woolf
Henry James
drafting
editing
revision
A computational corpus study of harmony in the music of Anton Webern

This thesis sets out to apply digital analysis to the music of Anton Webern, with the aim of quantifying elements of his harmonic style, and tracing their change across his practice. It is a corpus study, taking Webern’s 31 works with Opus numbers as its subject, and uses music21 for the data collection. Analytical subjects include distributions of pitch classes, intervals, and pitch-class sets; techniques for assessing these include clustering, regression analysis, and the Discrete Fourier Transform. Along the way, the thesis interrogates commonly-held assumptions about Webern’s music for which there is often little empirical evidence, and provides a multi-level perspective on the corpus, from the wide angle of whole-movement macroharmonies to the close-up detail of individual pitch-class sets. Chronologically, the results suggest that the advent of dodecaphony in Webern’s music had a limited effect on the surface features of the music he presented; rather that the major shift in his practice happened in his mid-period Lieder. Contra Allen Forte, I downplay the importance of octatonicism in his harmonic language in favour of a quartal quality, but in the process I explore the differing features between the various harmonic levels of Webern’s music.

Keywords: harmony
music analysis
pitch-class distribution
discrete fourier transform
corpus study
music21
atonal
pitch-class set
music information retrieval
serialism
Webern
computational musicology
dodecaphony
Advisor: Cross, J
Wittgenstein, criteria and the ineffability of consciousness

The present discussion seeks to determine the scope and nature of Wittgenstein's opposition to some prominent approaches to consciousness in contemporary philosophy of mind and cognitive science. We begin with some general remarks about this opposition, and in Chapter 1 appraise some prominent contemporary exemplars: Hacker & Bennett's (2003, 2007) Wittgensteinian critiques of attempts to study and define consciousness, and Searle (2007) and Block's (2007) opposing views. Their dispute hinges on whether Wittgenstein's notion of criteria yields a prima facie opposition to the distinction between consciousness and language (the 'being'/'saying' distinction) and more generally whether his later view is opposed to the ineffability of consciousness. We will demonstrate that while Wittgenstein's notion of criteria, properly understood, does provide a prima facie case against the 'being'/'saying' distinction (Chapters 2 and 3), there is an alternative sense in which Wittgenstein's view may endorse a notion of 'ineffable consciousness' importantly similar to that endorsed by Block (2007) and others. As such, Wittgenstein's position concurs neither with attempts by Block, Searle and others to distinguish consciousness from language, nor with claims such as Hacker and Bennett's which suggest a wholesale opposition to consciousness or its ineffability.

Keywords: philosophy of language
consciousness
MR Baker
Ludwig Wittgenstein
philosophy of cognitive science
John Searle
PMS Hacker
philosophy of mind
Ned Block
Improving GPs' knowledge of the benefits and harms of treatment to support decision making in multimorbidity: qualitative research and co-design of a novel electronic information resource

Background
General practitioners (GPs) regularly prescribe prolonged treatments for long-term conditions. However, GPs may benefit from further understanding of the absolute benefits and harms of these treatments, enhancing their ability to engage in shared decision-making and manage multimorbidity and polypharmacy.
Aim
To produce and evaluate a website to provide information on the benefits and harms of treatments for long-term conditions in a way that can be understood by GPs and potentially integrated into their practice.
Methods
The study consisted of three parts. First, a qualitative interview study and framework analysis with GPs exploring their attitudes to and understanding of the quantitative benefits and harms of treatments. Second, a participatory co-design process to design the website, coupled with a pragmatic approach to evidence collation to provide clinical content. Finally, an exploratory evaluation study of the website using online focus groups.
Results
The interview study reported findings on GPs’ understanding of quantitative information on the benefits and harms of treatments which informed the co-design research. The co-design research resulted in the creation of a website, www.gpevidence.org, which presents complex scientific information on treatment effect sizes and the nature and quality of the relevant clinical evidence.
The evaluation study showed that participating GPs were able to understand the clinical information on GP Evidence, and that in hypothetical scenarios this might change their prescribing practice. Some participants found some information confusing. There was limited evidence that this new information could be integrated into complex decision-making for multimorbidity and polypharmacy.
Conclusion
The aim of producing a website able to deliver information on the benefits and harms of treatments for long-term conditions to GPs was achieved. Further research is needed to evaluate the effect of GP Evidence in real-world practice.

Keywords: primary care
multimorbidity
polypharmacy
shared decision-making
Advisor: Greenhalgh, P
Mahtani, K
Neff, G
Crocker, J
Wieringa, S
Benchmarking the Union post-Brexit: analysing the impact of Brexit on Scottish voters' attitudes towards independence

Brexit has both complicated and reignited the Scottish independence debate but its effect on public opinion is uncertain. This study seeks to address this empirical question and further our understanding of support for Scottish independence by assessing the over-time effect of Brexit on independence attitudes during the Brexit negotiation period. To do this, it exploits British Election Study panel data and uses a series of change-on-change and fixed effects models to estimate the relationship between voters’ Brexit evaluations and independence attitudes over the Brexit process period. In so doing, it also investigates heterogeneity between sub-groups of Scottish voters. Its findings suggest that voters’ assessments of Brexit’s success/failure (particularly regarding its economic consequences) did influence their independence attitudes over this period. They also show that Brexit mattered most to those voters whose support in a future independence referendum will prove decisive – i.e., previously uncertain and unattached voters. This thesis attributes these findings to the “benchmarking” approach which conceptualises public opinion about constitutional change in rational, relational and dynamic terms. Using BES panel data to look through the lens of relative government performance assessments and an original online survey experiment to look through the lens of relative economic performance evaluations, it demonstrates that the “benchmarking” mechanism can be applied to the Scottish setting. Thus, it argues that the “benchmarking” approach not only serves as a useful theoretical tool to better understand the dynamics of independence support but also provides a plausible explanation for the link between Brexit and independence attitudes. In so doing, this thesis contributes to the literature on Brexit and Scottish nationalism, fills a gap in the literature regarding sub-group heterogeneity and, by applying ‘benchmark’ theory to the sub-national context, speaks to the larger literature on the dynamics of support for separatist movements within multinational states.

Keywords: economic evaluations
Brexit
secessionism
public opinion
survey experiment
benchmark theory
Scottish independence
Advisor: Green, J
Investigating the behavioural significance of the claustrum

Sequestered deep beneath the cortex, the claustrum is the most densely connected structure in the brain. This tantalizing anatomy has spawned a wide range of hypotheses regarding the function of the claustrum, but technological and biological constraints have hindered research. In this thesis, I have investigated the activity and behavioural function of the claustrum. I developed a novel preparation for recording claustrum activity using two-photon calcium imaging of claustrum axons in dorsal cortex. I show that claustrum axons display stimulus-locked changes in activity following uni- and multimodal sensory stimuli. While some axons were selective to one sensory modality, most were promiscuously responsive to multiple sensory modalities. I then investigated the behavioural consequences of silencing the claustrum. I detected no effects of claustrum silencing on home-cage activity, circadian behaviour, or a battery of tests assessing a wide range of behavioural domains. Finally, I investigated the impact of claustrum silencing on two behavioural tasks. While I detected no effects on a reversal learning task, I found that claustrum silencing reduced animals’ sensitivity to multimodal stimuli in a classical conditioning-like paradigm. Collectively, these results support the hypothesis that the claustrum may be involved in processing multimodal information and highlight the need for more research into the function of the claustrum.

Keywords: in vivo calcium imaging
sensory neuroscience
neuroscience
behavioural neuroscience
claustrum
Advisor: Packer, A
Butt, S