VictorJuiz/thesis huggingface dataset:
Dynamic modelling of overhead power lines for electric trains
Keywords: dynamic modelling
differential-algebraic equation
electric train
pantograph
pantograph-catenary
train

Electric and hybrid trains are popular across Europe and many overhead lines have been installed. The train collects electrical power from a high-voltage contact wire using a pantograph, which is a metal framework attached to the roof of the train. The contact wire is supported by a messenger wire through a series of vertical droppers, while registration arms maintain the horizontal stagger of the contact wire. The modelling of the pantograph-catenary interaction is an important part of overhead-system design and it is desirable to maximise the speed of simulation software while maintaining realism.
A Galerkin approach, also known as modal analysis, is used to solve the Euler-Bernoulli wire equations, as opposed to the typical finite-element methods. This approach was chosen to improve simulation speed and allow dynamically chosen velocity profiles to be modelled. Elimination of variables is then used to reduce the index-three differential-algebraic equation to an ordinary differential equation after eigenvector decomposition is used to diagonalise the system.
The model is validated against the 2002 and 2018 European Standards for pantograph-catenary simulation. Each of these standards provides an idealised model of an overhead system and requires that the simulation software produce results that are in agreement with the standard’s benchmark. The model is then tested against real data from the Old Dalby test track.
The model is shown to produce realistic results at excellent simulation speeds. The final model includes up to two pantographs, contact-wire transitions and dropper unloading. The equations used to produce the model are explained in detail, many results are presented and numerous ideas to further improve the model are described.
Interfacial strategies for improved solid-state lithium batteries
Keywords: lithium nitridothiophosphate
nitride electrolyte
SSB
lithium metal anode
SLEI
dendrite
critical current density

This project aims to help facilitate the step change in battery energy density (per volume) needed for improved consumer electronics and greatly increased electric vehicle adoption. The work in this thesis is focussed on enabling a lithium metal electrode to be successfully employed in a rechargeable battery as a negative electrode by using a protecting solid electrolyte.
In Chapter 4, the viability of using a solid-electrolyte (Li3N) to protect a lithium metal anode is explored and the phenomena that occur at this metal/ceramic interface during the passage of current are determined.
Chapter 5 explores a novel strategy of using a solid-electrolyte (Li3N) as a separator in a solid-electrolyte/liquid-electrolyte hybrid battery. By using liquid electrolyte, the cathodic instability of Li3N, as well as the volume expansion issues of cathodes with solid-electrolytes and the self-discharge problems associated with Li3N should theoretically be eliminated. The universality of solid-electrolyte/liquid-electrolyte interfacial phenomena are also examined by investigating an alternative solid-electrolyte (LLZTO) with a state of the art liquid-electrolyte used in commercial Li+ ion batteries (LP30).
Chapter 6 explores the chemistry of Li3N·P2S5 solid-electrolytes, as it is speculated that the electrochemical reduction of a nitrogenous electrolyte would form an SEI rich in Li3N, and would therefore produce self-healing and low resistance SEIs in contact with Li.
Challenges in probing inflation with primordial gravitational waves
Keywords: cosmology
primordial gravitational waves
cosmic microwave background
foregrounds
inflation

It is still not yet understood how structure in the Universe was seeded. The theory of inflation provides a framework to understand the origins of structure as quantum fluctuations of the vacuum, whilst maintaining an attractive simplicity, and giving a natural explanation of how the Universe is so flat, homogeneous, and isotropic. If inflation occurred, it would have produced a gravitational wave background, indirectly observable today through its effect on the polarization of the cosmic microwave background.
We present a new model for the polarized microwave sky, combining data from the Planck and WMAP satellites, and legacy radio surveys, with theoretical models for Galactic foreground SEDs. We present an example use-case of this model by forecasting the effect of Galactic foregrounds on a future satellite mission.
We then move on to consider an extension to the simplest inflationary scenario in which an additional set of SU(2) gauge fields are present during inflation, and may source a chiral gravitational wave background. We show that future CMB missions will not be able to distinguish such a scenario from the simplest single field slow-roll model using standard two- point statistical techniques, and that space-based laser interferometers will provide a complementary probe by constraining the short wavelength behavior of the blue-tilted gravitational wave spectrum.
Finally, we demonstrate the efficacy of a new method to account for complex Galactic foregrounds in the analysis of high-sensitivity polarized CMB data from the upcoming Simons Observatory. We first show that ignoring the spatial variation could lead to a false detection of a gravitational wave background, and that this can be corrected for by introducing additional parameters describing the spatial variation of the foreground spectral energy dependence.
Collective motion in active nematic liquid crystals
Keywords: Active Nematic Fluids
active nematic liquid crystals
Active Nematics
Active Matter
Soft Condensed Matter Theory

Active matter is based on understanding the physical mechanisms that give rise to large scale flows in aggregates of self-propelling particles. If the particles have a head-tail, or nematic, symmetry, then their structure resembles that of a passive nematic liquid crystal. However, unlike passive liquid crystals, the active injection of energy into the system by the particles’ self-propulsive motion results in collective motion, which gives rise to a class of fluids known as active nematic fluids. Experimental examples of such fluids include cytoskeleton biopolymers, bacterial suspensions, and cell monolayers. The topic of this thesis is to understand the physical mechanisms that result in, and how to control the often-times turbulent, collective motion of active nematic fluids.
First, continuum simulations are used to investigate how confinement can tame the motion of an active nematic fluid in a closed channel, and then compared to results from experiments. By regulating the width of the channel, which screens the active flows, we find a novel flow state and recover a variety of flow states. The characteristic wavelength is found to be dependent on the channel width but independent of the activity.
Secondly, we examined how active nematic droplets can migrate towards a chemical source that regulates the activity. The active nematic droplet is found to direct flows towards its interface, which when coupled to the symmetry breaking in the chemical field, results in a net migration towards the chemical source. We find that while small and large droplets migrate with the same root-mean-square velocity, the larger droplets are more direct in their migratory motion.
Finally, we apply the theory of active nematics at the cellular level by modelling a cluster of distinct cells using a multi-phase field approach. We drive the motion within the cluster using nematic forces that orient towards the direction of least cell-cell contact, as motivated by contact-inhibition-of-locomotion. Cell clusters are found to display a rich variety of dynamics, ranging from jammed and fluid-like motion in confluence, to wound healing and migration in open space.
Women and seventeenth-century manuscript culture : miscellanies, commonplace books, and song books compiled by English and Scottish women, 1600-1660
Keywords: song books
17th century
seventeenth-century
manuscript culture
manuscripts
commonplace books
miscellanies

The thesis analyzes the extent to which English and Scottish women participated in the thriving manuscript culture of the first half of the seventeenth century. It considers in detail the manuscripts of four women, paying particular attention to the poetry they have chosen to copy, alter, or create. In the first three chapters the following manuscripts are examined: the commonplace book of Ann Bowyer (Bodleian Library Ashmole MS 51), Lady Anne Southwell's miscellany (Folger Shakespeare Library MS V.b.198), and the miscellany of Constance Aston Fowler (Huntington Library MS HM 904). The fourth chapter examines women's participation in the musical life of England and Scotland, with a special focus on the song book of Lady Margaret Wemyss (National Library of Scotland Dep. 314/23).
Each of these manuscripts reflects in some way the personality of its compiler, but also the literary community of which she formed a part. This thesis considers both the material communities of like-minded people to which these women had access, and also the intellectual literary networks in which women could participate.
Women from the "middling sort," the gentry, and the aristocracy are all represented in the sample of manuscripts examined in the thesis. Puritan, via media or "Anglican," and Catholic positions are evident from the manuscripts. The women who compiled them lived in England, Ireland, and Scotland. A remarkably large range of women participated in manuscript culture, but the factors of class, religious affiliation, and location influenced the type of literary worlds which these women could tap into.
Poems circulating in manuscript often invited alteration, appropriation, and response. I argue that manuscript circulation could offer women and men a malleable medium for their reading and writing, but that this type of literary dissemination has particular significance for women, who traditionally were not encouraged to express themselves through the written word.
The writings of Walter Sickert and the new art criticism
Keywords: Walter Sickert
art criticism

This thesis looks at the writing and the painting of Walter Sickert and in particular at his part in the critical debate in art at the end of the nineteenth and the beginning of the twentieth centuries. Falling between the period in which Ruskin’s theories of art had been influential on the work of contemporary painters and the advent of the Modernist orthodoxy heralded by the writing of Roger Fry and Clive Bell, this period was viewed with extreme pessimism by many of the art critics of the day. The younger generation of English painters was looking towards France for its ideas, and an examination of the New Art Criticism reveals the influence of French art criticism. Sickert’s earliest art criticism is largely unknown but examined here, in the context of the other New Critics, it reveals the full extent of his understanding of French art and the significance he attached to the subject matter of paintings. It also helps to explain why he later found the theories of Fry and Bell so noxious. By examining Sickert’s earliest writing on art and by following the development of his ideas through both his painting and his later writing it is possible to place his late, and somewhat idiosyncratic, paintings within the context of a consistent ideology. While Sickert’s ideas may have appeared somewhat reactionary at the time, the subsequent decline of the Modernist ideology and the aesthetics that have developed since, all suggest that Sickert’s theory and practice was striving towards a definition of modern painting defined by its concern with the modern human condition.
The Theravādin doctrine of momentariness : a survey of its origins and development
Keywords: momentariness

The idea of the impermanence and transience of life is absolutely fundamental to Buddhist teachings. The first of the Three Characteristics (ti-lakkhana, dukkha, anatt), 'impermanence', is a doctrine constantly and emphatically insisted upon in the canonical texts. The radical and extended interpretation of this doctrine gave rise to the idea that the world is not made of enduring substances with changing qualities. Rather, reality is made only of events that flash into and out of existence, not only through the causal power of their chief cause but also through the influence of an entire causal complex. This is referred to as ksanikav¡da, the doctrine of momentariness.
There is disagreement among Buddhist thinkers about the exact meaning of the doctrine of momentariness. Some thinkers hold that no conditioned phenomenon can endure for more than a single moment, after which it stops existing. Others, though, argue that momentariness is not incompatible with duration; things are produced, endure and disappear. In particular, the Theravadins attempts to model the thought process in terms of the relative duration of material and mental phenomena. In fact, the Theravādin exegetes hold that a moment of matter lasts for as long as sixteen or seventeen thought moments.
The central part of this thesis examines the origin and development of this version of the doctrine of momentariness. There is difficulty in establishing when it appeared. Some scholars think that the Theravādins did not develop the doctrine early on in their history. They believe that it may have been interpolated into Theravādin textual sources at a later date, possibly by Buddhaghosa in the fifth century CE. I take quite a different position. My hypothesis is that the Theravādin doctrine of momentariness was embedded in the early Sinhalese commentaries. To prove it, I have made a close study of the textual evidence. All of it seems to confirm that the doctrine was formed early in the Theravādin tradition and that Buddhaghosa did not introduce the doctrine.
In its attempt to trace the textual history of the Theravādin doctrine of momentariness, this thesis contributes to the study of the early history of Buddhist thought, by examining the parallel textual sources of the early Southern and Northern traditions (between the first century BCE and the second century CE) before they are formalised, in the Visuddhimagga and the Abhidharmako'abh'sya respectively, in the fifth century CE.
The neurological consequences of non freezing cold injury
Keywords: Threshold tracking (nerve excitability testing)
Neuropathy
Small fibre neuropathy
Non freezing cold injury
Neuropathic pain
SCN9A

Non-freezing cold injury is a clinical syndrome characterised by altered sensory perception following prolonged exposure to cool temperatures. Acutely there is loss of sensation but after several hours or days, pain emerges in the distal extremities, which may last months or years after injury. The pain is characteristically more severe when the affected skin is cooled, at temperatures that would not have elicited pain before injury. The condition is well known in the military, most notoriously in The First World War as “Trench Foot”. New cases are still seen in the British Military in the 21st Century. There has never been a detailed study to address the neurological phenotype of patients with chronic symptoms. In this thesis 80 such patients underwent neurological phenotyping and assessment for the presence of neuropathic pain. The data in this thesis provide clear evidence for the presence of a sensory neuropathy with severe neuropathic pain due to small fibre neural injury, as demonstrated by abnormalities on quantitative sensory testing and reduced intraepidermal nerve fibre densities. Soldiers of African heritage have long been recognised to be predisposed to injury, raising the question of whether there could be a genetic contribution to this syndrome. Using a whole genome sequencing approach, a variant in the voltage gated sodium channel gene, SCN9A, was found to be over-represented in the cohort. Furthermore, in cellular electrophysiology experiments, the variant bestowed gain of function effects on HEK293 cells, but only at cool temperatures, providing a molecular correlate for the cold-aggravated pain seen in patients. Assessment of axonal excitability by threshold tracking suggests that there may be a reduction in slow potassium current, which has been shown to associate with neuropathic pain and cold allodynia. This thesis provides an evidence base for assessment and management of patients and suggests abnormalities in both sodium and potassium channel function, which warrant further research. This could have important implications for targeted therapy.
Wide deep neural networks
Keywords: initialization
signal propagation
deep learning
gaussian processes
neural networks

Deep neural networks have had tremendous success in a wide range of applications where they achieve state of the art performance. Their success can be generally attributed to three main pillars: their natural back-propagation structure which allows time and resources efficient gradient computation; recent advances in optimization theory which have led to the development of fast training algorithms; and availability of computationally efficient software (neural networks frameworks such as PyTorch and Tensorflow), hardware (Graphics Processing Units(GPUs), and more recently Tensor Processing Units(TPUs)).
Deep neural networks are now the model of choice for many practitioners. As a result, there is a growing research interest in their theoretical properties. Classical results from approximation theory ensure that neural networks, even with a single hidden layer, are universal approximators, provided the model is big enough. From an optimization point of view, the loss surface of a deep neural network is generally highly non-convex, posing a big limitation on what results from Optimization theory can be applied to such models. Therefore, little is known about the local minimas, the saddle points, and the convergence of gradient based method (e.g. Stochastic Gradient Descent), with these models. Another interesting and understudied research topic is that of randomly initialized neural networks. Indeed, random neural networks provide a compelling framework that offers, in many cases, a simplified short-cut to understand theoretical properties of neural networks at initialization and Bayesian neural networks. Against this backdrop, the research presented in this thesis focuses on the theoretical properties of randomly initialized wide deep neural networks. It provides a comprehensive analysis of these models at initialization, leveraging a duality between random wide neural networks and Gaussian processes. Particularly, the research here presented pays careful attention to the role of the initialization hyperparameters, the activation function, and the neural architecture in the behaviour of these models. This level of depth allows for the derivation of principled guidelines for the training and designing of deep neural networks.
Wilkie Collins and the politics of adaptation on the Victorian stage
Keywords: copyright
adaptation
Wilkie Collins
intellectual property
theatre
Victorian literature and culture

As the sensation novel was reclaimed by literary critics and cultural historians as a legitimate site of academic inquiry in the mid-twentieth century, Wilkie Collins’s canonical works became the topic of much scholarly interest. His works have consistently been identified as the locus of a plethora of narrative and formal innovations that have irrevocably shaped how we understand both the Victorian novel and its successors. As this thesis will demonstrate, however, Collins’s writing for the stage – in particular dramatising his own novels – had a more significant influence on his career than has previously been acknowledged. By reading those dramatic works alongside their novelistic versions and against the landscape of Victorian theatre, this thesis refines our understanding of this canonical novelist while also demonstrating the interrelatedness of the novel and the stage for Victorian readers, writers, audiences, and critics.
The central proposition of this thesis is that our understanding of cultural production in the nineteenth century has been shaped by literary criticism’s insistent focus on the novel, and that research attuned to the amorphous formal boundaries that characterised the careers of Victorian writers reveals the mutually constitutive relationship between the novel and the theatre. In offering a chronological account of Collins’s theatrical writing, this thesis demonstrates how the social, psychological, and political complexity woven into the fabric of his novels gets adapted, repurposed, and represented in their dramatic versions, revealing both their narrative complexity and investment in the social and political ethos of Collins’s England.
The theological power of film: embodiment, time, and the work of Andrei Tarkovsky
Keywords: Andrei Tarkovsky
Theology
Philosophy of Religion
Embodiment
Time
Film Theory
Phenomenology

This thesis contributes to the interdisciplinary study of theology and film. It recognises that the prevailing methodologies in this study seldom prioritise questions about the formal properties of cinema as an artistic medium, and so overlook several productive and substantial questions for the theologian: What theology and theological practice does cinematic art give rise to? What are the perceptual and affective potentials of film for theology, and what, if anything, is theological about the cinematic medium itself? In condensing and synthesising these inquiries, I offer this central research question: What is the theological power of film? By prioritising these questions, this thesis engages in theological-cinematic analysis which aims to render a properly theological account of the medium of film. This account constitutes a shift away from the ‘textual’ analysis of film, towards an ‘experiential’ analysis of the art form itself. As such, this is not a matter of ‘applying’ theological concepts to film. Rather, ‘the theological power of film’ designates the medium’s power to express, signify, prime and perform certain conceptual and theological practices. In this way, the film experience is the proper subject of an inquiry into the theological power of film, and so this thesis adopts a phenomenological method, drawing on a major project of recent cinematic theory: film-phenomenology. Foregrounding the body in the film experience through the Merleau-Pontian concept of the body-subject, I argue for an understanding of cinema as a haptic and somatic medium of perception-cum-expression. The embodied nature of the art form also reveals the distinct temporality of film, for our embodied being in the world is indissolubly connected with our being in time. The films and writings of Andrei Tarkovsky emerge as the fulcrum of my response, as his work becomes a singular illustration of the theological power of film.