VictorJuiz/thesis huggingface dataset:
Planar heterojunction perovskite solar cells via vapour deposition and solution processing
Keywords: Perovskite
Hybrid inorganic-organic
Solution processing
Solar cells
Vapour deposition

Hybrid organic-inorganic solar photovoltaic (PV) cells capable of directly converting sunlight to electricity have attracted much attention in recent years. Despite evident technological advancements in the PV industry, the widespread commercialisation of solar cells is still being mired by their low conversion efficiencies and high cost per Watt. Perovskites are an emerging class of semiconductors providing a low-cost alternative to silicon-based photovoltaic cells, which currently dominate the market. This thesis develops a series of studies on “all-solid state perovskite solar cells” fabricated via vapour deposition which is an industrially-accessible technique, to achieve planar heterojunction architectures and efficient PV devices.
Chapter 2 presents a general outlook on the operating principles of solar cells, delving deeper into the specific operational mechanism of perovskite solar cells. It also explores the usual methods employed in the fabrication of perovskite thin films. Chapter 3 describes the experimental procedures followed during the fabrication of the individual components constituting the device from the synthesis of the precursors to the construction of the functioning perovskite PV devices. Chapter 4 demonstrates pioneering work involving the dual-source vapour deposition (DSVD) of planar heterojunction perovskite solar cells which generated remarkable power conversion efficiency values surpassing 15%. These significant results pave the way for the mass-production of perovskite PVs. To further expand the range of feasible vapour deposition techniques, a two-layer sequential vapour deposition (SVD) technique is explored in Chapter 5. This chapter focusses on identifying the factors affecting the fundamental properties of the vapour-deposited films. Findings provide an improved understanding of the effects of precursor compositions and annealing conditions on the films. Chapter 5 concludes with a comparison between SVD and DSVD fabricated films, highlighting the benefits of each vapour deposition technique.
Furthermore, hysteretic effects are analysed in Chapter 6 for the perovskite PV devices fabricated based on different structural configurations. An interesting discovery involving the temporary functioning of compact layer-free perovskite PV devices suggests the presence of a built-in-field responsible for the hysteresis of the cells. The observations made in this chapter yield a new understanding of the functionality of individual cell layers. Combining the advantages of the optimum vapour deposition technique established in Chapter 4 and Chapter 5, with the enhanced understanding of perovskite PV cell operational mechanism acquired from Chapter 6, an ongoing study on an “all-perovskite” tandem solar cell is introduced in Chapter 7. This demonstration of the “all-perovskite” tandem devices confirms the versatility of perovskites for a broader range of PV applications.
Incremental sheet forming: modelling and path optimisation
Keywords: metal forming
path optimisation
incremental forming
limit analysis
rigid plastic

Incremental sheet forming (ISF) is a novel metal shaping technology that is economically viable for low-volume manufacturing, customisation and rapid-prototyping. It uses a small tool that is controlled by a computer-numerically controlled sequence and the path taken by this tool over the sheet defines the product geometry. Little is currently known about how to design the tool-path to minimise geometric errors in the formed part. The work here addresses this problem by developing a model based tool-path optimisation scheme for ISF. The key issue is how to generate an efficient model for ISF to use within a path optimisation routine, since current simulation methods are too slow. A proportion of this thesis is dedicated to evaluating the applicability of the rigid plastic assumption for this purpose. Three numerical models have been produced: one based on small strain deformation, one based on limit analysis theory and another that approximates the sheet to a network of rods. All three models are formulated and solved as second-order cone programs (SOCP) and the limit analysis based model is the first demonstration of an upper-bound shell finite element (FE) problem solved as an SOCP. The models are significantly faster than commercially available FE software and simulations are compared with experimental and numerical data, from which it is shown the rigid plastic assumption is suitable for modelling deformation in ISF. The numerical models are still too slow for the path optimisation scheme, so a novel linearised model based on the concept of spatial impulse responses is also formulated and used in an optimal control based tool-path optimisation scheme for producing axisymmetric products with ISF. Off-line and on-line versions of the scheme are implemented on an ISF machine and it is shown that geometric errors are significantly reduced when using the proposed method. This work provides a new structured framework for tool-path design in ISF and it is also a novel use of feedback to compensate for geometrical errors in ISF.
In the shadow of politicisation
Keywords: liberalisation
services market
European policy-making

This thesis researches the variation in levels of liberalisation within the European services market, focusing in detail on four selected service sectors (i.e. postal services, electricity services, healthcare services and the services covered by the Services Directive) from 2001 until 2011. In this thesis, I propose a model of European integration capable of explaining the exact levels of liberalisation in each service sector. I argue that the level of liberalisation can be explained by looking at the drivers of integration (i.e. expected economic benefits from further integration and the level of supranational activity), which determine the societal demand for further integration and the shape legislators’ preferences and constraints, and the intervening influence of adhoc politicisation (i.e. the influence of public opinion through mass mobilisation). To illustrate this, this thesis applies a two-tiered approach of analysis. First, it explains the context in which the legislation is made to understand the economic implications of the proposed legislation, the level of supranational activity preceding the tabling of the legislation and the preferences of all actors involved. Second, taking preferences as exogenously given, this thesis applies a method of process tracing to study in detail the negotiations between legislators – the amending stage of the legislation. The case studies show that the drivers are crucial to explain the general demand for integration and at the same time show how politicisation, taking various guises, influences the level of liberalisation – primarily by altering legislators’ relative power. Particularly interesting is that politicisation can affect the negotiations even in absence of politicisation actually materialising causing some legislation to be made in the ‘shadow of politicisation’. These findings confirm existing explanations of European integration and add new insights as to how we can understand the process of European integration more generally.
Novel adenoviral vectored vaccines and the implications of viral diversity in therapeutic strategies against Hepatitis C Virus infection
Keywords: adenoviral vectors
vaccines
viral sequence
T cells
Hepatitis C Virus

Hepatitis C virus (HCV) is a major global pathogen estimated to infect over 170 million people worldwide. A recent study has shown that vaccination with adenoviral vectors, based on rare human and simian serotypes encoding the non-structural (NS) proteins of HCV, induces highly potent, multi-specific and durable T cell responses in healthy human volunteers. In this thesis I assess the safety and immunogenicity of these vaccines (ChAd3–NSmut and Ad6-NSmut), for the first time in HCV infected patients. This work also explores whether vaccine-induced T cell responses target in vivo circulating HCV antigens and common naturally occurring epitope variants.
Patients with treatment naive chronic genotype 1 HCV infection were vaccinated (i.m.) with ChAd3-NSmut and Ad6-NSmut in a heterologous prime boost schedule, either with or without current IFN and ribavirin (IFN/RBV). Epitope-specific T cell responses were defined by fine mapping using HCV peptides. Circulating viral genomic sequence was determined in vaccinated patients at baseline and at any point of viral relapse. Cross-reactivity of vaccine-induced T cell responses was determined in T cell assays, using peptides corresponding to both circulating host virus and common population HCV epitope variants. An in vitro dendritic cell /T cell priming model was used to identify possible candidates for a cross-reactive vaccine immunogen at the most immunodominant epitope, NS31406.
33 patients were vaccinated. Vaccination was well tolerated. At the highest vaccine dose (2.5 x 1010vp) vaccine-induced T cell responses were detectable in 11/20 patients receiving concurrent IFN/RBV and 2/4 patients receiving vaccination alone. In total 14 antigenic targets were identified, 2 of which have not previously been described. However, T cell responses were of lower magnitude and more narrowly focused than those observed in healthy volunteers vaccinated with the same regimen.
Analysis of viral sequence showed that in many cases vaccine-induced T cells did not target the circulating virus. At the most immunodominant epitope (NS31406), T cells induced by vaccination failed to target common circulating genotype 1 HCV variants. An in vitro model suggested that in order to target all genotype 1 sequences at this epitope, it would be necessary to insert both a genotype 1a and 1b version of this epitope into a vaccine immunogen.
Vaccination with adenoviral vectors induces T cell responses in patients with chronic HCV infection, however immune responses are attenuated compared with healthy volunteers. Ultimately a successful therapeutic or prophylactic vaccine strategy will rely on inducing responses that target conserved or cross-reactive epitopes.
Extensions of the case-control design in genome-wide association studies
Keywords: gwas
association tests
genome-wide association studies

The case-control design is one of the most commonly used designs in genome- wide asociation studies. When we increase the sample size of either the controls or, more importantly, the cases, the power of whatever test we use will certainly increase. However increasing the sample size, means that addi- tional individuals need to be genotyped and this implies extra financial costs. However, nowadays with the emergence of genetic studies, a large number of genetic data are available at low or no extra cost. Even though those data may not be completely relevant to the current study, they can still be used to increase the probability to identify true associations. Furthermore, additional information, non-necessarily genetic, can also be used to improve the power of a method.
In this thesis we extend the case-control design in order to take ad- vantage of such types of additional data and/or information. We discuss three designs; the case-cohort-control, the kin-cohort and the super-case– case–control–super-control designs. For each of these, we present methods that are adjusted or modified versions of standard case-control methods but we also propose novel ones developed with those extended designs in mind. Ultimately, we describe how those methods can be used in order to increase the power of association tests, especially compared to similar methods of the case-control design.
Reading for pleasure in Britain: trends, patterns, and associations
Keywords: sociology of culture
lsype
taking part
reading for pleasure
bcs70

This thesis investigates reading for pleasure in Britain from a variety of perspectives, in the context of popular concerns surrounding levels of readership, particularly among young people, and consists of four substantive chapters.
The first chapter reports how book sales and library circulation have changed, and what predicts readership in the Taking Part survey. I show that claims surrounding changes in reading in Britain may be overstated, although the number of issues from British libraries has fallen, and that while the predictors of readership are largely as expected, there are some important results surrounding social status, and ethnic differences in children.
The second chapter investigates changes in young people’s reading behaviour, using the Longitudinal Study of Young People in England. I show that changes in young people’s reading cannot be explained through a displacement effects account, and that socioeconomic differences in readership do not increase as panel members get older.
In the third chapter, I investigate whether the relationship between reading for pleasure and educational attainment can be explained through cultural capital, and extend this with occupational attainment, using the 1970 British Cohort Study. I show a relationship between reading for pleasure and occupational attainment net of education, and I show that this relationship seems to have a cultural dimension beyond a cognitive effect account.
In the fourth chapter, I show that the relationship between leisure in adoles- cence and educational and occupational attainment is not driven purely by highbrow activities, as on a certain understanding of Bourdieu: in particular, I show a relationship between occupational attainment and middlebrow activities.
Religion in Tacitus' Annals
Keywords: Tacitus
Roman historiography
Roman religion
Annals
cultural memory

I examine how religion is presented in the Annals of Tacitus, and how it resonates with and adds complexity to the larger themes of the historian’s narrative. Memory is essential to understanding the place of religion in the narrative, for Tacitus constructs a picture of a Rome with ‘religious amnesia.’ The Annals are populated with characters, both emperors and their subjects, who fail to maintain the traditional religious practices of their forebears by neglecting prodigies and omens, committing impious murders, and even participating in the destruction of Rome’s sacred buildings. Alongside this forgetfulness of traditional religious practice runs the construction of a new memory – that of the deified Augustus – which leads to the veneration of living emperors in terms appropriate to gods. This religious narrative resonates with and illuminates Tacitean observations on the nature of power in imperial Rome. Furthermore, tracing the prominence of religious memory in the text improves our understanding of how Tacitus thinks about the past, and particularly how he thinks about the role of the historian in shaping memory for his readers.
I consider various religious categories and their function in Tacitus’ writings, and how his characters interact with them: calendars (do Tacitus’ Romans preserve or change the traditional scheduling of festivals?), architecture (what determines the building of or alterations to temples and other religious monuments?), liturgy (do they worship in the same ways their ancestors did?), and images (how do they treat cult statues?). I analyze the patterns of behaviour, both in terms of ritual practice and in how Tacitus’ characters think about and interpret the supernatural, and consider how Rome’s religious past features in these patterns. The thesis is structured according to the reigns of individual emperors. Four chapters chart Tiberius’ accession, Germanicus’ death, its aftermath, and Sejanus’ rise to power; one chapter examines the religious antiquarian Claudius; and the final chapter analyzes Nero’s impieties and their consequences.
Control and observation of DNA nanodevices
Keywords: strand displacement
synthetic reaction networks
DNA nanotechnology

The uniquely predictable and controllable binding mechanism of DNA strands has been exploited to construct a vast range of synthetic nanodevices, capable of autonomous motion and computation. This thesis proposes novel ideas for the control and observation of such devices. The first of these proposals hinges on introducing mismatched base pairs into toehold-mediated strand displacement – a fundamental primitive in most dynamic DNA devices and reaction networks. Previous findings that such mismatches can impede strand displacement are extended insofar as it is shown that this impediment is highly dependent on mismatch position. This discovery is examined in detail, both experimentally and through simulations created with a coarse-grained model of DNA. It is shown that this effect allows for kinetic control of strand displacement decoupled from reaction thermodynamics.
The second proposal improves upon a previously presented strand displacement scheme, in which two strands perform displacement cooperatively. This scheme is extended to be cascadable, so that the output of one such reaction serves as input to the next. This scheme is implemented in reaction networks capable of performing fundamental calculations on directed graphs.
The third proposal is exclusively concerned with a novel observation methodology. This method is based on single-molecule fluorescence microscopy, and uses quantum dots, a fluorescent type of semiconductor nanocrystal, as a label. These quantum dots display a set of characteristics particularly promising for single-molecule studies on the time- and length scales most commonly encountered in DNA nanotechnology. This method is shown to allow for highly precise measurements on static DNA devices. Preliminary data for the observation of a complex dynamic device is also presented.
A study of atom and radical kinetics
Keywords: master equation
equilibration
dissociation
rate constants
vinyl
sensitivity analysis
equilibrium
radicals
hydrogen
combustion
diffusion
association
atoms
oxygen
FACSIMILE
ethyl
allyl
methyl
CHEMKIN
enthalpy
density of states
kinetics
nonlinear

This thesis describes the measurement of rate constants for gas phase reactions as a function of temperature (285 ≤ T/K ≤ 850) and pressure (48 ≤ P/Torr ≤ 700). One or both reactants was monitored directly in real time, using time–resolved resonance fluorescence (for atoms) and u.v. absorption (for radicals). Reactants were produced by exciplex laser flash photolysis. The technique was used to measure rate constants to high precision for the following reactions under the stated conditions: • H+O2+He->HO2+He and H+O2−→OH+O, for 800 ≤ T/K ≤ 850 and 100 ≤ P/Torr ≤ 259. A time–resolved study was performed at conditions close to criticality in the H2–O2 system. The competition between the two reactions affected the behaviour of the system after photolysis, and the rate constants were inferred from this behaviour. • H+C2H4+He<-->C2H5+He (T = 800 K, 97 ≤ P/Torr ≤ 600). The reactions were well into the fall–off region at all conditions studied. At 800 K, the system was studied under equilibrating conditions. The study provided values of the forward and reverse rate constants at high temperatures and enabled a test of a new theory of reversible unimolecular reactions. The controversial standard enthalpy of formation of ethyl, DH0f,298 (C2H5), was determined to be 120.2±0.8 kJ mol−1. Master Equation calculations showed that reversible and irreversible treatments of an equilibrating system should yield the same value for both thermal rate constants. • H+C3H5+He->C3H6+He (T = 291 K, 98 ≤ P/Torr ≤ 600) and O+C3H5 −→ products (286 ≤ T/K ≤ 500, 48 ≤ P/Torr ≤ 348). Both reactions were pressure–independent, and the latter was also independent of temperature with a value of (2.0±0.2) ×10−10 cm3 molecule−1 s−1. • H+C2H2+He<-->C2H3+He (298 ≤ T/K ≤ 845, 50 ≤ P/Torr ≤ 600). At 845 K, both reactions were in the fall–off region; rate constants were used to determine the standard enthalpy of formation of vinyl, ¢H0f,298 (C2H3), as 293±7 kJ mol−1. The value of this quantity has until recently been very controversial. • H+CH4 <--> CH3+H2. The standard enthalpy of formation of methyl, DH0 f,298 (CH3), was determined by re–analysing existing kinetic data at T = 825 K and 875 K. A value of 144.7±1.1 kJ mol−1 was determined. Preliminary models were examined to describe the loss of reactants from the observation region by diffusion and pump–out. Such models, including diffusion and drift, should prove useful in describing the loss of reactive species in many slow–flow systems, enabling more accurate rate constants to be determined.
Enantiorecognition phenomena in asymmetric synthesis
Keywords: Organic synthesis

This thesis is concerned with investigations into applications of double asymmetric induction and parallel kinetic resolution in asymmetric synthesis.
Chapter 1 introduces enantiorecognition phenomena as a significant field in asymmetric synthesis. The main approaches in this field are described: double asymmetric induction, kinetic resolution, parallel kinetic resolution and dynamic kinetic resolution.
Chapter 2 describes investigations into the use of double asymmetric induction as a mechanistic probe to elucidate the reactive conformation of enantiopure α,β-unsaturated esters (derived from Corey’s 8-phenylmenthol auxiliary) and hydroxamates [derived from (S)-N-1-(1'-naphthyl)ethyl-O-tert-butylhydroxylamine] upon conjugate addition.
Chapter 3 describes investigations into the doubly diastereoselective organocatalytic intramolecular Michael cyclization of enantiopure enamides (derived from a 4-substituted-5,5-dimethyl-oxazolidin-2-one auxiliary) and α,β-unsaturated esters (derived from Corey’s 8-phenylmenthol auxiliary) using α-methylbenzylamine and its derivatives as the chiral catalysts.
Chapter 4 describes investigations into parallel kinetic resolution of acyclic γ-amino-α,β-unsaturated esters utilising a 50:50 pseudoenantiomeric mixture of lithium amides. To highlight the synthetic utility of the resultant β,γ-diamino esters, their elaboration to a range of 5-substituted-4-amino-pyrrolidin-2-ones is demonstrated and a concise synthesis of natural product (±)-absouline is performed.
Chapter 5 contains full experimental procedures and characterisation data for all compounds synthesised in chapters 2, 3 and 4.