VictorJuiz/thesis huggingface dataset:
Improving the performance and reproducibility of lead - tin perovskite absorbers toward all-perovskite tandem solar cells
Keywords: narrow band gap
lead-tin
tandem solar cells
DMSO-free
perovskites
precursor phase
photovoltaics

This thesis explores a subset of hybrid perovskites that incorporate tin into their crystal lattice alongside lead. Hybrid perovskite semiconductors have gained global interest over the past decade due to their remarkable optoelectronic properties, and excellent power conversion efficiencies, which now compete with well-established commercial technologies. By incorporating tin, these materials can achieve band gaps far narrower than their pure-lead counterparts. This property makes lead-tin perovskite materials suitable for the construction of all-perovskite tandem solar cells to improve power conversion efficiencies beyond the theoretical limit for a single junction device. Although these materials are promising and have been successfully demonstrated to achieve high power conversion efficiencies, they are still far below their theoretical efficiency and comparatively few studies have been conducted on how to maximise the potential of this class of materials. The work presented in this thesis explores three topics utilising an FA0.83Cs0.17Pb0.5Sn0.5I3 absorber. In the first instance a bulk passivation strategy is investigated with the aim to reduce non-radiative recombination in the absorber material, using several thiocyanate additives that are found to successfully enhance the photoluminescence quantum efficiency of the material and improve charge carrier diffusion length. Proceeding this, the influence that selective contact materials have on non-radiative recombination is explored culminating with a passivation strategy at the interface with the electron transport material. This led to enhanced performance of resulting devices. Chapter 5 details the fabrication of 2T-monolithic tandem solar cells. The successful resolution of fabrication issues, and optimisation of the lead-tin sub-cell generated highly efficient tandem solar cells. The final experimental chapter in this thesis investigates the removal of DMSO from the lead-tin precursor ink due to its ability to oxidise Sn2+ to Sn4+, which can cause detrimental effects within the material. This is achieved by the addition of the ammonium halide salt DMACl. It is shown that highly oriented thin films can be fabricated with enhanced grain sizes leading to a much-improved device stability, in air, of over four times that of the device utilising DMSO.
Unravelling the degradation pathways and charging mechanism in the Li-O2 battery: the role of singlet oxygen

Keywords: Rechargeable batteries
Singlet Oxygen
Li-O₂ batteries
Li-air batteries

Lithium-oxygen batteries (LOBs) have attracted immense research interest as they have the highest theoretical energy density among the advanced battery systems. Achieving such high energy densities can substantially reduce the need for fossil fuels, enable greater use of renewable energy, and revolutionise the transportation sector. However, due to the complexity of oxygen reduction and evolution reaction chemistries and reactivity of reduced oxygen species, LOBs still need significant improvement in their fundamental understanding to overcome the electrolyte and cathode stability issues.
In the Thesis, firstly, the redox mediated charging process was studied to understand the mechanism to enable fast charging with low overpotentials and side reactions. It is demonstrated that the redox mediated oxidation follows Marcus theory of electron transfer and the rate limiting step is the first 1-electron oxidation, Li2O2 → LiO2. The kinetically dominant step is the LiO2 disproportionation. It is also shown that the singlet oxygen (1O) yield does not correlate with the amount of degradation. This casts doubt on whether 1O2 is the main cause of degradation in LOBs.
Secondly, due to the discrepancy in 1O and electrolyte degradation amounts, the stability of the common LOB salts and solvents towards 1O2 were tested. It is shown that tetraglyme-LiTFSI, one of the most widely used electrolytes, is stable towards 1O2 under chemical conditions. In the LOB literature, 1O2 is mainly detected and quantified using DMA, a 1O2 trap. Here, it is revealed that DMA can react with superoxide depending on the salt-solvent combination and DMAO2, the reaction product of 1O2 with DMA, can degrade into by-products depending on the solvent environment.
Finally, the stability of the electrolyte and the cathode towards 1O2 under electrochemical conditions and the real cause of faradaic efficiency loss are investigated. It is demonstrated that 1O2 is not the main source of degradation and fresh Li2O2 surfaces is the culprit. This finding should redirect the focus of LOB research from avoiding 1O2 to developing electrolytes inert towards peroxide and peroxide-derived side products for an electro/chemically stable cell.
Sublinear rigidity of lattices in semisimple lie groups
Keywords: metric rigidity
Lie groups
sublinear neighbourhoods
Quasi-isometry
SBE
sublinear bilipschitz equivalence
quasiisometry
lattices
discrete subgroups of Lie groups
buildings

In this thesis I prove metric rigidity results for lattices in real semisimple Lie groups without compact factors and with trivial centre. Let G be such a group. The first result is that if the sublinear neighbourhood of a discrete subgroup of G contains a lattice, then it is itslef a lattice. In case the group G does not admit real rank 1 factors, I prove that the classses of uniform and non-uniform lattices of G are SBE-complete, generalizing the well known quasi-isometric completeness of these classes.
Individualising the use of radiotherapy for the treatment of people with Hodgkin lymphoma
Keywords: decision-making
risk estimation
radiotherapy
late-effects
hodgkin lymphoma

Hodgkin lymphoma is a cancer of the lymphatic system that typically affects young adults. Chemotherapy and radiotherapy are both highly effective treatments, and 80-90% of patients now become long-term survivors, living long enough to experience late toxicities. Radiotherapy in particular has been shown to increase the long-term risk of cardiovascular disease and second malignancies, and recent trials have attempted to identify patients in whom radiotherapy can be omitted. Omission of radiotherapy has, however, been shown to substantially increase the chance of Hodgkin lymphoma recurrence. The decision about whether or not to use radiotherapy for an individual patient therefore involves weighing up the proven benefit against the potential risks of late toxicity.
The aim of this thesis is to understand the decision-making process about radiotherapy, and provide data that can be used to inform patients and clinicians at various steps. I explore patients’ and clinicians’ experience of radiotherapy decision-making, and propose a new decision-making model that fits this context. I present a comprehensive summary of the late toxicities of radiotherapy, including the dose-response relationships that can be used to estimate risks from modern radiotherapy. I report the radiation dose received by abdominopelvic organs in a historic cohort of Hodgkin lymphoma survivors, and show how the data has been used to estimate the dose-response relationship for the risk of colorectal cancer. Finally, I present a multivariable linear regression model that estimates the dose a patient’s heart would receive from radiotherapy using measures available at the time of their diagnosis. I use the model to estimate individual patient’s risk of ischaemic heart disease, and show its accuracy is greatest in the medium heart dose range, where the balance of the benefits and risks of radiotherapy are most uncertain.
Overall, this thesis helps inform individualised decision-making about radiotherapy by highlighting how clinicians can support patient involvement in decisions and providing methods to help individualise risk estimates of radiotherapy late toxicity.
The critique of Kantian Epistemology in the early religious philosophy of S. L. Frank
Keywords: Semyon Frank
Russian Philosophy
philosophy of religion
Kant

This thesis presents the first critical analysis of the early religious philosophy of Semyon Liudwigovich Frank (1877-1950). The analysis aims to demonstrate that Frank’s early philosophy contains a powerful attack on Kantian epistemology and later Kantian thought. Although the methodology here is primarily intellectual-historical, attempt is made throughout to present Frank’s thought as a ‘powerful’ rebuttal, precisely by re-emphasising its philosophical merits. Frank remains drastically undiscovered in Western philosophy of religion and his highly original and carefully developed epistemology deserves a thorough examination.
The analyses of Frank’s work are preceded by intellectual-historical accounts of Frank’s previous alignment with Neo-Kantianism and the essential broader context of the key treatise of his early period, The Object of Knowledge. The analyses themselves reconstruct Frank’s philosophy in seven chapters, which critically address key areas of his thought. The six arguments which stand out as ‘powerful’ are Frank’s epistemological argument for our ‘knowledge’ of all things, the argument from consciousness, the arguments from syllogism and predication, Frank’s original Ontological Argument, and finally the argument from universals. The fourth and final section takes a more evaluative approach and defends two aspects of Frank’s thought in light of contemporary philosophy of religion: Frank’s apophaticism and his realism of universals.
In light of these considerations, it can be concluded that Frank’s early religious thought, as presented in The Object of Knowledge, should be considered, first and foremost, as a powerful attack on the Kantian epistemology which Frank himself had once professed.
Bayesian methods for battery state of health estimation
Keywords: lead-acid
Gaussian Process regression
battery state of health
parameterisation
li-ion
bayesian methods

Estimating the state of health of battery energy storage systems is key to their operational safety and reliability, both of which affect lifetime cost. However, accurate estimation of state of health remains challenging, as measurement techniques used in laboratory environments are not available in real-world operating environments. In this work, a framework is developed that combines the relative strengths of commonly applied model- and data-driven approaches to state of health estimation. Gaussian process regression, a flexible Bayesian method of learning arbitrary functions from input-output data, is applied to estimate the parameters of low-order battery models as functions of internal states, operating conditions and lifetime. The approach is first motivated by the difficulty of parameter identification for physics-based battery models from real-world data. Then it is shown how electrical equivalent circuit models can be extended to include parameter dependencies on operating conditions and lifetime in a data-driven manner. The framework is then applied to two different usage scenarios. First, internal resistance is estimated for a fleet of solar-connected lead-acid batteries located in sub-Saharan Africa, where the resulting health metric is shown to provide an early indication of end-of-life failure. Second, a first-order RC circuit, coupled with a one-state thermal model, is parameterised in a joint process that also simultaneously estimates battery states, using data from a Li-ion cell under laboratory conditions. The only prerequisite was the cell-level open-circuit voltage versus charge curve and, in the case of the Li-ion cell model, a single thermal parameter. Given this, the method is agnostic to chemistry and battery construction. Enabling robust and fast state of health estimation for large fleets of batteries has the potential to `close the loop' in terms of battery energy storage system design. Instead of performing laboratory-based ageing experiments, field data can be used directly to determine factors that affect battery life. By incorporating this information into fault diagnosis and health-aware battery management systems, safety and reliability will be improved. Furthermore, with deeper understanding of degradation in the real world, better design of energy storage systems will ultimately lead to better cost efficiency through reduced over-engineering.
A self-inflating vp/mma hydrogel expander as a potential treatment for Crohn’s Disease problem
Keywords: vinyl pyrrolidone
GI Tract
Short Bowel Syndrome
Hydrogel Tissue Expander
methyl methacrylate
Crohn's disease

Crohn’s disease (CD) is associated with chronic inflammation in regions throughout the gastrointestinal (GI) tract but is most likely to develop at the end of the small intestine and the first part of the colon. A single massive resection or multiple repeated resections in CD leads to short bowel syndrome (SBS). Therefore, a novel treatment to cure SBS is needed. Poly (vinyl pyrrolidone-methyl methacrylate) hydrogel is chosen as a self-inflating expander device to address the issue of inadequate functional intestinal length in SBS. The hydrogel employs mechanotransduction, wherein mechanical force elongates the intestine and activates cellular mechanisms regulating growth. In this study, the VP/MMA hydrogel was designed by varying the composition ratio of each monomer and size. The ratios of VP to MMA were 95:5wt%, 90:10wt%, and 85:15wt%. The shape of hydrogel was cylindrical with the sizes of 12mmD & 3mmL (A), 6mmD & 3mmL (B), 6mmD & 6mmL (C), 6mmD & 9mmL (D), 3mmD & 3mmL (E). These variables influenced the pore size structure, swelling capacity, swelling force, and mechanical property. Finally, the hydrogel with a composition ratio of 85:15 wt% VP/MMA (VP85) was chosen for ex vivo and in vivo studies. The reason is due to the pressure generated during swelling (77.9 kPa) close to the required stress value to stretch the small intestine (78.9 kPa). Due to the small size of the rat intestine, the 2mmD & 2mmL hydrogel was chosen. A stretched segment of the intestine was found to lengthen 2.5-folds from the original length on days 1 and 7. Histological intestine sample after being stretched using hydrogel showed a significantly greater muscularis thickness, crypt depth and villous height.
Laser-accelerated ions and their applications
Keywords: plasma physics
ion acceleration

Since the first studies of target-normal sheath acceleration around the year 2000, production of energetic ion beams from intense laser-matter interactions has been investigated in great depth. New acceleration mechanisms such as radiation pressure acceleration, collisionless shock acceleration, the hybrid breakout afterburner mechanism, and special regimes such as light-sail radiation pressure acceleration have been discovered and demonstrated. Applications of ion beams produced by these mechanisms range from common diagnostic techniques for laser plasma interactions to industrial radiography and even—albeit needing significant improvements to predictability and reproducibility before this can be realised—their proposed use in medical treatments like hadron therapy, which if successful could significantly reduce the cost to hospitals of hosting such therapies. I present work on three topics around laser-accelerated ion beams and their applications: Firstly, I present an experiment which sought to demonstrate acceleration of ions from a laser-driven collisionless shock within a plasma produced from low-density plastic foam. This acceleration mechanism produces ions with a narrow energy spectrum, compared to the more well-established target-normal sheath acceleration. Despite limitations to the accessible experimental conditions, I present evidence that ions were accelerated with the narrow energy spectrum characteristic of this mechanism. Secondly, I introduce the reader to an important application of fast ion beams: the proton radiography diagnostic. This diagnostic is used to measure the electromagnetic fields present in a plasma through their influence on a beam of protons as it traverses the plasma. I explain the theory of proton radiography and describe a laser-plasma channelling experiment on which proton radiography was used to probe the magnetic fields associated with a laser-produced plasma channel. I demonstrate the analysis of some proton radiographs using an improved solver I have implemented in a community analysis package. Finally, I propose improving the information accessible to the proton radiography diagnostic by making observations of the plasma from several different directions, a procedure I term ‘proton tomgraphy’. I then derive methods of improving the quality of data recovered from proton tomography. Compared to standard tomographic algorithms I achieve an orders-of-magnitude improvement in reconstrution quality of synthetic data when very few lines of sight are available
Do women only have rights when it is economically profitable? Limits of the legislative rationality behind international women’s rights
Keywords: feminist theory
human rights
critical theory
international law
critique of political economy

The thesis studies how capitalist logic is ingrained in the fabric of women’s rights; and argues that it limits women’s rights’ ambitions and possibilities to emancipate women. The inquiry is based on two case-studies of adopting international women’s rights: the UN Convention on Marriage (UNCM) granting women a right to reject forced marriage; and CEDAW, granting women a right to family planning in its Art. 16 e). The thesis, in the context of the case-studies, shows that a combination of capitalist imaginaries of women’s needs, means of emancipation and the deference to ‘autonomous’ economic forces are imprinted in the legal form of women’s rights. These imaginaries come together in a core unemancipatory dynamic of the rights. This dynamic is such that the aim of the legal form signified under ‘rights’ is not women’s attainment of power or entitlements, but a creation of conditions for women to join the course of ‘autonomous’ economic forces which will then presumably lead to this attainment. This technology within the rights then functions to distribute emancipation and subordination according to the structures of patriarchal and racial capitalism. This perspective helps explains why poor and non-Western women are structurally subordinated by and within the merit of the mentioned rights, despite these rights being adopted to empower these exact women.
How bilingual language experience shapes the infant lexicon: implications for word learning and lexical access
Keywords: infant research
cognates
bilingualism
vocabulary questionnaire
language development

In this thesis, I investigate how the words known by bilingual toddlers affect their learning of new words. I explore phonological and semantic connections both within and between languages. I analyse vocabulary questionnaire data collected via parent report for bilingual and monolingual toddlers growing up in the UK. Firstly, I show that while bilinguals’ English vocabulary size lags behind that of monolinguals, conceptual vocabulary size is similar across groups. Notably, when words across both languages are added together, bilinguals understand many more words compared to monolinguals. Bilinguals’ vocabularies include words with the same meaning across languages (translation equivalents). I found that if a word is known in one language (e.g., English "dog"), they have a high likelihood of also learning its translation equivalent (i.e., Spanish "perro"). Additionally, the acquisition of translation equivalents may be supported by systematicity between phonology and meaning. Even monolingual adults are able to make use of cross-linguistic similarity to guess the meaning of unfamiliar foreign words. I show that bilingual toddlers learn cognates (translation equivalents with phonological overlap) earlier than non-cognates, suggesting that toddlers can make use of cross-linguistic similarity to support word learning. Toddlers also display sensitivity to semantic connections in their language(s). Using semantic network analyses, I show that high frequency words and words that have a large number of associative connections to other words are learnt earlier by toddlers than words with low frequency and few connections to other words. The words within a toddlers’ lexicon also have dense connectivity with each other, much more than would be expected if associative patterns in the learning environment had no impact on word acquisition order. Findings from this thesis highlight how bilingual toddlers can capitalise on phonological and semantic connections between words to facilitate learning two languages in parallel.
Multi-level proteomics profiling of virus-restrictive and -permissive cellular environments to discover novel regulators of virus infection
Keywords: proteome
interferon alpha
RNA bound proteome
transcriptome
phosphoproteome
HEK293
mass spectrometry
permissive
HEK293T
restrictive
virus infection

Viruses rely on host cell resources to replicate and propagate. To mitigate, human cells can express a diverse set of antiviral proteins to combat virus infection. Understanding the host proteins that aid or repress virus infection can be instrumental for the development of novel antiviral strategies. This recent decade has witnessed rapid developments in discovering host proteins that regulate virus infection. However, our current knowledge of the landscape of host proteins that drive or restrict virus infection remains largely incomplete. Here I employed a multi-level proteomics analysis to identify novel regulators of virus infection in a model system that comprises cells highly permissive to viruses (HEK293T), cells at steady-state (HEK293), and cells restrictive to viruses (HEK293 stimulated with interferon alpha (IFN-α)). This analysis examines changes in protein and RNA abundance, phosphorylation, and RNA binding across different cellular states. Whole-cell proteomic analysis revealed that HEK293T cells are depleted of well-established antiviral factors and enriched in proteins that interact with viral protein and RNA, which could explain its high permissiveness to virus infection. Proteome-wide comparative analysis also highlights that a number of proteins exhibit distinct expression patterns across permissive, steady-state, and restrictive cellular states, including genes that have not been previously associated with IFN-α response. Further analysis comparing cellular proteome and transcriptome discloses substantial discordances between protein- and RNA-level responses after IFN-α stimulation. The analysis of RNA-bound proteome (RBPome) shows, for the first time, that IFN-a stimulation alters the protein-RNA interaction landscape in human cells. An in-depth phosphoproteomic analysis of IFN-α stimulated cells provides evidences that IFN-α could regulate the cellular RBPome through phosphorylation of RNA binding proteins. By integrating evidences from multiple levels, I have selected and generated stable expression cell lines for 19 candidate genes to test their potential regulatory roles in viral fitness. Collectively, this study provides an information-rich dataset that examines host determinants of virus-permissive or restrictive cellular states from multiple levels. This could be a valuable source for further analysis and validation studies to discover regulators of virus infection.