VictorJuiz/thesis huggingface dataset:
Novel pneumatic circuit for the computational control of soft robots
Keywords: soft robotics
pneumatic circuit
computation
magnetorheological elastomer

Soft robots are of significant research interest in recent decades due to their adaptability to unstructured environments and safe interaction with humans. Soft pneumatic robots, one of the most dominant subsets of soft robots, utilize the interaction between soft elastomeric materials and pressurized air to achieve desired functions. However, the systems currently used for signal computation and pneumatic regulation often make use of rigid valves, pumps, syringe drivers, microcontrollers et al. These bulky and non-integrable devices limit the performance of pneumatically-driven soft robots, carrying challenges for the robot to be miniaturized, untethered, and agile. This DPhil aims to develop pneumatic circuits that can be integrated into the soft robot bodies while performing both onboard computation and control.
This thesis presents our contributions towards the aforementioned objective step by step. Firstly, we designed a 3D-printable bistable valve with tunable behaviours for controlling soft pneumatic robots. As an integrable control device, the valve stores one bit of binary information without requiring a constant energy supply and correspondingly controls a pneumatic chamber. Secondly, in order to reduce the number of valves required to control multi-chamber soft robots, we introduced a modular approach to design multi-channel bistable valves based on the previous work. Thirdly, in order to achieve continuous pressure modulation with integrable devices, we designed a soft proportional valve, utilizing the continuous deformation of Magnetorheological Elastomer (MRE) under magnetic flux. Apart from the analogue activation manner, this design also ensures a fast response time, operating at a time scale of tens of milliseconds, much shorter than the mechanical response time of most soft pneumatic actuators. Fourthly, to achieve onboard proportional control of multi-chamber soft robots, we developed an MRE valve array with an embedded cooling chamber. Physical experiments showed that our MRE valve array ensured the independence and accuracy of each valve unit within it, with a significantly lowered temperature of 73.9 o
C under 5 minutes of operation. Lastly, we developed an open-source software toolbox supporting the design of integrable pneumatic logic circuits to enhance their accessibility and performance. The toolbox comes with a graphical user interface (GUI) to take users' desired logic functions in the form of a truth table and a set of 2D space constraints related to the available space onboard the robot. It then schedules the pneumatic circuit which performs the desired computation within the space constraints and produces a 3D-printable CAD file that can be fabricated and used directly.
The work presented in this thesis enables the community to simplify the process of integrating control devices into soft pneumatic robots, thereby paving the way for a new generation of fully untethered and autonomous soft robots.
Random convex hulls and kernel quadrature
Keywords: hypercontractivity
nyström approximation
random convex hulls
kernel quadrature
cubature

Discretization of probability measures is ubiquitous in the field of applied mathematics, from classical numerical integration to data compression and algorithmic acceleration in machine learning. In this thesis, starting from generalized Tchakaloff-type cubature, we investigate random convex hulls and kernel quadrature.
In the first two chapters after the introduction, we investigate the probability that a given vector θ is contained in the convex hull of independent copies of a random vector X. After deriving a sharp inequality that describes the relationship between the said probability and Tukey’s halfspace depth, we explore the case θ = E[X] by using moments of X and further the case when X enjoys some additional structure, which are of primary interest from the context of cubature.
In the subsequent two chapters, we study kernel quadrature, which is numerical integration where integrands live in a reproducing kernel Hilbert space. By explicitly exploiting the spectral properties of the associated integral operator, we derive convex kernel quadrature with theoretical guarantees described by its eigenvalue decay. We further derive practical variants of the proposed algorithm and discuss their theoretical and computational aspects.
Finally, we briefly discuss the applications and future work of the thesis, including Bayesian numerical methods, in the concluding chapter.
Identification and characterisation of chloroplast 3C and 4C monocarboxylate and dicarboxylate transporters involved in the C4 cycle
Keywords: Photosynthesis
C4 photosynthesis
Chloroplast transporters

C4 photosynthesis is a highly efficient form of photosynthesis that utilises a biochemical pump to concentrate CO2 around rubisco. This biochemical pump is dependent on multiple transport steps to move metabolites between organelles and between cells. However, the transporters that carry out several of these transport steps have evaded identification or characterisation. This lack of molecular characterisation is a major gap in our understanding of terrestrial photosynthetic biology, and also represents a significant barrier to attempts to engineer C4 photosynthesis into C3 crop species to improve yield. This thesis aims to address this problem and identify and characterise some of the missing transporters of the C4 pathway. The first half of this thesis is focussed on the characterisation of the HATCH1 transporter, demonstrating its function in E. coli and assessing the impact of the loss of this transporter (and its paralog) on C4 photosynthesis in Setaria viridis. Ultimately, I demonstrate that HATCH1 is involved in, but not necessary for, C4 photosynthesis and likely acts redundantly with other unknown transporter(s). The second half of this thesis concerns the identification and molecular characterisation of putative metabolite transporters of the C4 cycle in Zea mays. Whilst HATCH1 and HATCH3.1 were identified as candidate C4 cycle transporters, in planta data does not support this. In vitro and in planta data suggest a potential role for another candidate transporter in transport of C4 cycle metabolites at the chloroplast envelope of the bundle sheath cell. Together the results from this thesis increase our understanding of intracellular metabolite transport in C4 plants, and bring us closer to being able to engineer this trait into C3 plants.
Development of functional group tolerant and room temperature hydrogen borrowing enolate alkylation reactions
Keywords: iridium
methodology
borrowing hydrogen
ketone alkylation
hydride
organic chemistry
organometallic
mechanistic studies
general
complexes
photochemistry
enolate alkylation
functioal group diverse
alcohols
catalysis
room temperature
hydrogen borrowing
mild

This thesis describes work completed to expand the scope of hydrogen borrowing enolate alkylation reactions. It was hypothesised that the development of a room temperature reaction would allow utility of a breadth of chemical space previously undemonstrated in these reactions at high temperatures (80–180°C). The first strategy to achieve this was via the generation of excited state intermediates of the hydrogen borrowing cycle using visible light energy and a designed catalyst. A room temperature visible light driven reaction was realised and detailed mechanistic studies unveiled the role of visible light.
Later a light independent room temperature reaction was discovered and further developed to vastly expand the usable chemical space in hydrogen borrowing enolate alkylation reactions. A diverse range of nitrogen rich heterocycles were also demonstrated at higher temperatures (85°C) and mechanistic studies explained the need for anaerobic conditions in the reaction at room temperature.
Tailored nanocrystal catalysts
Keywords: epitaxial strain relaxation
scanning tunneling microscopy
strontium titanate
heteroepitaxy
finite-element method
x-ray photoelectron spectroscopy

The thesis explores the synthesis, characterization, and simulation of the heteroepitaxial monometallic (Ni, Ag, Pd) and bimetallic (Ni@Ag) systems on SrTiO3 substrates.
In monometallic systems, the morphology of nanocrystals is shaped by the combined influence of thermodynamics and kinetics. Factors like crystal volume, metal species, substrate terminations, deposition temperature, post-annealing temperature, and duration collectively influence the nanocrystal’s shape. Extended post-annealing shows a strain relaxation characterized by increased crystal height.
In some monometallic systems, a transition is observed from multi-twinned nanoparticles to single crystals. Comparisons across these systems reveal that factors such as surface/interface energy, elastic constants, surface stress effect, and twin boundary energy collectively influence the critical size at which this transition happens.
The synthesis of Ni@Ag core-shell nanoparticles on SrTiO3(001) is achieved via sequential deposition and annealing at 500◦C. Scanning tunneling microscopy (STM) images highlight a transition from mixed shapes to uniform truncated pyramidal shapes with increased annealing temperature. The h/l ratio analysis, based on STM images, further suggests a core-shell structure. X-ray photoelectron spectroscopy (XPS) results display a pure Ni peak only in the annealed sample, and the selective Ag removal by sputtering rules out the possibility of Ni-Ag alloy formation.
The strain energy in the Ni and Ni@Ag systems was simulated using the finite-element method. The strain energy displays a layered distribution. A simulation for the observed heightening effect for strain energy relaxation is provided. In the Ni@Ag-SrTiO3(001) system, the Ag shell consistently exhibits compressive strain, while the Ni core shows tensile strain. The simulations further reveal that the smaller height-to-length ratio in Ni@Ag, in comparison to the pure Ni core, results from the compressive strain in the shell, corroborating previous experimental findings.
These findings broaden our understanding of heteroepitaxial systems on SrTiO3 substrates and the influence of epitaxial strain on morphologies. This knowledge serves as a stepping-stone towards enhanced synthesis of tailored nanomaterials for a broad range of applications.
Development and non-equilibrium functions of a supramolecular oscillator
Keywords: organic synthesis
supramolecular
autocatalysis
systems chemistry
origin of life

Lipids are an important class of chemicals which appear simple in isolation, but collectively show complex supramolecular dynamics. Biology uses lipids ubiquitously and this thesis demonstrates ways in which chemical systems of lipids can emulate traits found in living systems. The primary theme of this thesis is how synthetic, metastable lipids can generate unexpected complexity, for example through emergent selection mechanisms and unique chemically oscillating systems.
Chapter 1 gives a general introduction to self-reproducing lipids both in the context of prebiotic chemistry and as a source of valuable systems-level behaviour. Physical autocatalysis is introduced and presented as a central principle in origins of life research and for related applications. Special consideration is given towards the generation of structural complexity and out-of-equilibrium concepts, both which are important hallmarks of life.
Chapter 2 describes an investigation into competition between self-reproducing lipids. Mixtures of lipids which continuously form and breakdown over time revealed two selection mechanisms, one of which involved an unexpected reaction pathway for some lipids, at the expense of competitors. This work showed new ways that simple chemicals may have become dominant species in prebiotic environments.
Chapter 3 introduces a unique supramolecular oscillator based upon autocatalytic micelles. The development of this system and its core principles are discussed in detail. Supported by high resolution kinetics and other control experiments, the underpinning mechanism of the oscillator is explored. This system has several properties which set it apart from other chemical oscillators and will be a source of interesting chemical systems in the future.
In Chapter 4, the responsivity of the oscillator is used to transduce information in waves of chemical concentration. Fine control over the frequency and period over the waveforms is shown. Chapter 5 uses the oscillator to guide the transport of chemical cargo between phases, as a demonstration of the potential spatiotemporal control that is possible with such systems.
Do leaders matter? International conflict, leader traits, and leader selection
Keywords: leaders
counterfactual
leader selection
international conflict

Why do leaders start conflicts? The bulk of IR tends to look outside of leaders, focusing on institutional and structural forces. Where there is more uncertainty is whether the factors within leaders might also influence their decision to start conflicts. Thus, this thesis asks the question: To what extent do the personal traits of leaders influence their decision to start international conflicts? Recent literature has found that several traits of leaders strongly predict conflict initiation, such as military experience and age. However, these findings may be biased if leaders with these traits are more likely to be selected into environments where the probability of conflict is greater. Yet, this problem of selection has not been given enough attention in previous research. To deal with the problem of selection, I develop a unique strategy, which I call the “counterfactual leader strategy.” The core idea of this strategy is that each time a leader is selected in reality, there is a counterfactual world in which someone else was selected instead. I call these individuals “counterfactual leaders” and the traits of these individual can be used as a “placebo” to indirectly test for bias. Since the counterfactual leaders' traits should not be associated with conflict initiation, any association reveals bias in the traits of leaders. Using an original dataset on leaders and counterfactual leaders between 1945 and 2004, I find that several traits of counterfactual leaders predict conflict in the same way as those traits among leaders. I argue this is because states that frequently engage in conflict are more likely to have candidates with these traits due to demographics and thus have a higher probability of selecting a leader with one, even if by chance. Therefore, I argue traits do not influence leaders’ decision to start conflicts, and what matters instead is the environment they are selected into.
Commenting on ancient texts: interpreters and their audience in the Graeco-Roman world
Keywords: papyrology
ancient Egypt
bibliology
Greek paleography
commentaries
classical philology
ancient scholarship

The present study offers the first comprehensive work on papyrus commentaries in the context of ancient scholarship. Each chapter treats a different aspect of these texts. In Chapter 1 I provide the reader with a general overview of the main features of ancient commentaries in terms of content and layout, analysing a selection of examples focusing on different literary genres and comparing them to their modern counterparts. In Chapter 2 I study the material characteristics of papyrus commentaries, i.e. handwriting, use of the recto / verso, presence / absence of abbreviations, corrections, lectional and critical signs, and physical reinforcements of the papyrus. Chapter 3 takes into account the other main ‘exegetical typologies’ (treatises, marginal annotations, paraphrases, hypotheses, diegeseis), and studies in particular their similarities and differences with respect to commentaries. Finally, Chapter 4 investigates the contexts of production, use, and safekeeping of papyrus commentaries, i.e. whether they could belong to students, teachers, or scholars, and could be kept in public or private libraries and collections. This study intends to offer a better understanding of how ancient people read and studied their ‘classics’ in the light of the fundamental testimony of papyrus fragments.
An edition of Svipdagsmál
Keywords: Old Norse
Old Norse poetry
Svipdagsmál
edition
manuscripts

Section I of this thesis establishes a text of the two Old Norse poems Gróugaldr and Fjǫlsvinnsmál, known collectively as Svipdagsmál (Sv). Previous editions are surveyed, discussing their use of the two MSS upon which the emended text offered by this edition is based, Stockholm Papp. 15 8vo and Rask 21 a (I.1). Reasons are given for the choice of these two MSS (out of the forty six MSS known to the editor) and the two MSS are described (I.2). The emended and normalised text is accompanied by a translation and summary apparatus (I.3), followed by a Commentary (I.4). A reconstruction is attempted of the history of the MS tradition (I.5). This reconstruction is based on computer collation of the MSS and database analysis of the collation, together with external evidence where available. The reconstruction confirms the choice of Stockholm Papp. 15 8vo and Rask 21 a: most of the other MSS appear descended from one of these two.
Section II gathers together analogues to the poems in Celtic, Icelandic and Scandinavian ballad tradition. The story was earlier an Irish mythical tale, itself an adaptation of an international popular tale of the "giant's daughter" type (II.2). Traces of this original tale are to be found in Icelandic popular tradition (II.3). The Scandinavian Ungen Svendal ballads seem derived from Sv itself (II.4).
Section III analyses the poet's use of Old Norse poetic and mythological materials. The poems are skilful studies in Eddic style (III.2) and the poet shows a deliberate creativity in the adaptation and invention of mythological material (III.3-5).
Evidence is presented for a date of composition in the early thirteenth century (IV.1). A study of the art of the poems shows a poet of rare skill (IV.2).
Measurement of oscillations in solar boron-8 neutrinos and studies of optical scattering in the SNO+ detector
Keywords: optical calibration
Bayesian Analysis
neutrino
particle physics
MCMC
neutrino oscillations
SNO+
solar neutrinos

SNO+ is a large-scale liquid scintillator experiment based in Sudbury, Canada, capable of probing many aspects of neutrinos. One major property of interest is the neutrino’s ability to oscillate between different flavours, an indirect demonstration that neutrinos must have mass.
This thesis performs the first ever measurement of oscillations from 8B solar neutrinos in the scintillator phase of SNO+. Assuming the current global fit flux of 8 B solar neutrinos, the neutrino oscillation parameter theta_12 was measured to be 38.9 degrees +8.0-7.9 degrees, using an initial 80.6 days of data. This result is consistent with the current global fit result of 33.44 degrees +0.77-0.74 degrees. A sensitivity study indicates that the precision of this result is capable of improving by at least a factor of two within two years of livetime.
On top of this, substantial improvements were made to all aspects of the optical calibration system known as SMELLIE. This is a series of optical-wavelength lasers whose light is emitted from optical fibres attached to the edge of the SNO+ detector. By developing a new analysis, this system was able to measure the scintillator extinction lengths as a function of wavelength and time in-situ for the first time. A new analysis was also built and demonstrated to observe changes in scattering and scintillator re-emission properties of the scintillator as a function of time and wavelength. Alongside this, major upgrades were made to both the hardware and simulation of the SMELLIE system, enabling higher-quality data to be taken, and simulations to be made with much greater speed.
Uneven pathways: three novel mechanisms of intergenerational transmission of (dis)advantages
Keywords: inequality
social stratification
intergenerational transmission of advantage
child development

This thesis advances the understanding of the socioeconomic inequalities in children’s development by examining three novel mechanisms of intergenerational transmission of (dis)advantages. These channels are founded on a dynamic understanding of the process of social reproduction. Each one is illustrated with reference to the cases of the UK or the US.
The first empirical chapter examines how parents respond to their children’s early physical health problems and delves into the enduring consequences of these parental responses. Using twins fixed effects models, the findings reveal that, on average, parents exhibit negative responses when their children face early health problems, and that these responses have a lasting negative impact on the children’s educational achievements. Surprisingly, the effect of health problems on parental responses does not vary across socioeconomic groups. The second study examines whether mothers adapt their level of cognitive stimulation as a response to children’s developmental declines, and whether this is a socially stratified process. The results obtained from a series of two-way fixed effects and fixed effects counterfactual models indicate that, on average, mothers respond to their children’s skills declines by reducing their cognitive stimulation. This pattern is especially pronounced within impoverished families or those with low educational levels. In the final empirical chapter of this thesis, attention shifts to exploring whether mothers’ occupation-specific skills influence the process of development of their children. Exploiting changes in mothers’ jobs during their children’s upbringing, the results suggest that mothers’ mathematical occupation-specific skills have a positive effect on children’s mathematical ability and that high-SES children especially benefit from the skills upgrading of their mothers.
This dissertation discusses the substantive implications of each of these mechanisms and tests them empirically. It is only by disentangling the complex combination of channels through which inequality is transmitted across generations that appropriate policy responses can be elaborated.