VictorJuiz/thesis huggingface dataset:
Development of an aerosol-CVD technique for the production of CNTs with integrated online control
Keywords: chemical vapour deposition
carbon nanotubes
aerosol-assisted chemical vapour deposition
carbon nanomaterials

This dissertation summarises the study of different aspects of the aerosol-assisted chemical vapour deposition (AACVD) technique for the production of multi-wall carbon nanotubes (MWCNTs). Upscaling the synthesis while retaining the quality of MWCNTs has been a prime objective throughout the work. A key aspect of this work was the study of different growth parameters and their influence on the homogeneity of the products across the reactor. The effect of the precursor composition on the yield and quality of MWCNTs were also investigated. It was shown that the synthesis rate can be significantly (60 – 80 %) increased by tuning the composition of the precursor. Moreover, by optimising the synthesis recipe and using a larger reactor, the synthesis rate and efficiency of the precursor were increased fivefold (up to 14 g/hr) and twice (up to 88 %) respectively. Large area (up to 90 cm2), mm-thick carpets of MWCNTs which were both free-standing and on substrate were produced. The carpets could withstand normal handlings without tearing apart, making them suitable for macroscopic characterisations and applications. By in-situ qualitative and quantitative gas analysis of the atmosphere of the reactor, the thermocatalytic cracking behaviour of 25 precursors was investigated and a mechanism for successive formation of different hydrocarbon fragments inside the reactor was proposed. A number of dedicated gas analysis methods and apparatuses such as a probe for zone-by-zone gas analysis of reactor and a heated chamber for preparation of standard gas analysis samples were developed to explore some of the least investigated aspects of the thermocatalytic cracking of precursors. Mapping the reactor revealed that some single-wall and double-wall carbon nanotubes (SWCNTs and DWCNTs) were also produced near the exhaust of the reactor. The SWCNTs were partly covered by fullerene-like species and resembled different forms of carbon nanobuds. In addition, the effect of the electron beam on the interaction of the SWCNTs and the fullerene-like species was studied in situ using high-resolution transmission electron microscopy (HRTEM).
The string axiverse and cosmology
Keywords: physics
astrophysics
cosmology
string theory

This thesis studies the cosmology of ultra-light scalar fields with masses in the range 10−33 eV ≲ m ≲ 10−18 eV and their effects on cosmology. The existence of such fields is motivated by the theoretical framework of the "String Axiverse". All types of string theory contain multiple axion fields associated with antisymmetric tensor fields compactified on closed cycles in the compact space. Since the masses of these fields scale exponentially with the volume of the cycle, it is possible for them to be naturally light. We study the effects of these fields as a component of the dark matter and show analytically and numerically that they cause a suppression of structure formation on cosmological scales set by the inverse mass. We show that it will be possible with future galaxy redshift and weak lensing surveys to detect an ultra- light field comprising of order a percent of the total dark matter. If such a field is allowed to couple to the geometry that provided its mass via a phenomenological scalar potential for the axion and modulus, then the expansion of the universe can be altered significantly. In particular, we find that it is possible to have multiple epochs of accelerated expansion over a large region of parameter space, and to have a flat universe with a big crunch in the distant future. Finally, we address the issue of isocurvature perturbations in axion cosmologies, and demonstrate that in the ultra-light case the power spectrum is effected. This may have implications for the conclusions made about fine tuning in the axiverse in relation to a potential detection of tensor modes in the CMB that are different to the case of a standard axion.
Aerodynamic and mechanical performance of a high-pressure turbine stage in a transient wind tunnel
Keywords: aerodynamics
turbomachinery
transient wind tunnel
mechanical performance of a high pressure turbine stage

Unsteady three-dimensional flow phenomena have major effects on the aerodynamic performance of, and heat transfer to, gas-turbine blading. Investigation of the mechanisms associated with these phenomena requires an experimental facility that is capable of simulating a gas turbine, but at lower levels of temperature and pressure to allow conventional measurement techniques. This thesis reports on the design, development and commissioning of a new experimental facility that models these unsteady three-dimensional flow phenomena. The new facility, which consists of a 62%-size, high-pressure gas-turbine stage mounted in a transient wind tunnel, simulates the turbine design point of a full-stage turbine. The thesis describes the aerodynamic and mechanical design of the new facility, a rigorous stress analysis of the facility’s rotating system and the three-stage commissioning of the facility. The thesis concludes with an assessment of the turbine stage performance.
Roman diet and nutrition in the Vesuvian region:  a study of the bioarchaeological remains from the Cardo V sewer at Herculaneum
Keywords: Herculaneum
Archaeology
food
Pompeii
Italy
nutrition
diet
Roman
archaeobotany
fish

The Roman town of Herculaneum, due to its burial by the eruption of Vesuvius in AD79, provides the rare opportunity to study the diet of middle and lower class Romans living in an urban context in mid-1st century AD Italy. Knowledge concerning Roman diet, prior to the growth of bioarchaeology in the 1960s and 1970s, was derived from the ancient texts and focused primarily on the elite diet. The diets of the poorer classes have often been considered monotonous and unhealthy and consequently, malnutrition is believed to have been widespread in urban centres. Collaboration between the numerous sub-disciplines of bioarchaeology, including archaeobotany and zooarchaeology, has begun to take place amongst scholars working on the Vesuvian sites and diet is currently being studied using a more holistic approach. The ancient sources act as a secondary resource and it is now the physical food remains that play a crucial role in examining Roman diet and associated topics such as trade, health and nutrition.
This thesis investigated the bioarchaeological remains from the Cardo V sewer that ran beneath the shop/apartment complex of Insula Orientalis II in Herculaneum. It is the first large scale study to combine both new and existing bioarchaeological material from Herculaneum in an effort to provide the site with its own bioarchaeological data set, particularly with regards to food and diet. In total, 220L of soil was examined for carbonized and mineralized seeds, seashells, eggshells and fish bones. 194 taxa were identified, included including 94 botanical, 45 fish, 53 shellfish and two bird taxa. 114 of the 194 taxa can be considered edible foodstuffs. The statements of the ancient authors concerning dietary diversity have been examined in light of these findings and found to be comparable. The material displayed little taphonomic bias when compared to Pompeian bioarchaeological assemblages. The excellent preservation of the material, combined with data from modern food sciences, has allowed for much needed interpretation to take place in the areas of health and nutrition. The variety of cereals, fruits and seafood indicate close connections with the nearby land and sea and consequently, the economic implications of such extensive resource exploitation have been considered. A nutritional analysis of the finds have shown that diets were nutrient dense and healthy, enabling the people of Herculaneum to achieve modern day stature as well as survive and recover from illness. Thus it can no longer be assumed that those of moderate means ate an unhealthy and monotonous diet, that malnutrition was widespread in urban centres, and finally, that descriptions of foodstuffs in the ancient sources apply only to the wealthy.
Dangerous Politics
Keywords: risk
New Labour
penal policy
dangerousness
British politics
judiciary
pressure groups
criminal justice

The thesis constitutes a detailed historical reconstruction of the creation, contestation and subsequent amendment of the Imprisonment for Public Protection sentence, the principal ‘dangerous offender’ measure of the Criminal Justice Act 2003. Underpinned by an interpretive political analysis of penal politics, the thesis draws on a detailed analysis of relevant documents and 53 interviews with national level, policy-oriented actors. The thesis explores how actors’ conceptions of ‘risk’ and ‘the public’ interwove with the political beliefs and political traditions relied upon by the relevant actors. It is argued that while there was general recognition of a ‘real problem’ existing in relation to dangerous offenders, the central actors in the creation of the IPP sentence crucially lacked a detailed understanding of the state of the art of risk assessment and management (Kemshall, 2003) and failed to appreciate the systemic risks posed by the IPP sentence. The creation of the IPP sentence, as with its subsequent amendment, is argued to highlight the extreme vulnerability felt by many government actors. The efforts of interest groups and other pressure participants to have their concerns addressed regarding the systemic and human damage subsequently caused by the under-resourcing of the IPP sentence is explored, and the challenge of stridently arguing for substantial change while maintaining ‘insider’ status is discussed. As regards senior courts’ efforts to rein in the IPP sentence, it is argued that the increasingly conservative nature of the judgments demonstrate that the judiciary are not immune from the creep of a ‘precautionary logic’ into British penal politics. Regarding the amendment of the IPP sentence, the Ministry of Justice’s navigation between the twin dangers of a systemic crisis and a political crisis are explored. In conclusion, the IPP story is argued to demonstrate a troubling ‘thoughtlessness’ by many of the key policymakers, revealing what is termed the ‘banality of punitiveness.’ The potential for a reliance on political beliefs and traditions to slip into this thoughtless state, and possible ways of ensuring that such policy issues are engaged with in a more inclusive and expansive manner, are discussed.
"Not to offer himself again and again": an exegetical and theological study of repetition in the letter to the Hebrews
Keywords: Second Temple Judaism
New Testament
repentance
repetition
epistle to the Hebrews
cult
baptism
sacrifice
early Christianity

Repetition has received a bad press in certain streams of theological tradition; this reception has in part been caused by, and has in turn affected, readings of the Letter to the Hebrews, which speaks about repetition in ways unique in the New Testament. The present study addresses the insufficient critical attention paid to repetition in Hebrews, challenging the assumption that it functions uniformly and negatively throughout the letter, and exploring the variety of ways in which Hebrews presents repetition. The plurality of prophetic speech displays God’s manifold kindness in the old covenant; such speech is not opposed to but is fulfilled in Christ’s coming, and its ongoing repetition in the new covenant through citation and exposition serves to promote and explicate that event. Repeated mutual encouragement is essential to persevering in the Christian life and avoiding apostasy. And the regular entry of the Levitical priests into the outer sanctuary of the tabernacle in Heb 9.6 foreshadows the continual access to God achieved through Christ. Where repetition has a negative or contrastive role in the author’s argumentation, it does not cause inefficacy but rather indicates a weakness whose source is elsewhere – and which, moreover, is revealed fully only in the light of the Christ event. The uniqueness of Christ and of his death construed as a sacrifice, developed from concepts of singularity in Day of Atonement and early Christian crucifixion traditions, forms a unifying strand in the letter’s Christology. Rather than functioning in simple opposition to repetition, this singularity corresponds to continuity and eternity, and is developed at times in contrast to, and at times in correspondence with, repetition. The study thus offers a reappraisal of repetition in Hebrews, laying the foundations for renewed appreciation of the importance of repetition for theological discourse and religious life.
Characterisation and targeting of stem cells in myelodysplastic syndromes
Keywords: stem cells
myelodysplastic syndromes

Understanding which cells within a cancer are responsible for its initiation and propagation is vital if we are to achieve cure. If cancer stem cells are the only population able to sustain a tumour long term, designing therapeutic strategies to target this population will give medical science the best chance of long-term cure. Significant controversy remains over the existence of cancer stem cells, predominantly due to the lack of a sensitive human cancer stem cell assay. This thesis investigates whether two haematological malignancies, myelodysplastic syndromes (MDS) and chronic myelomonocytic leukaemia (CMML) can only be driven by rare and distinct cancer stem cells. We have demonstrated that low and intermediate-1 risk MDS is driven solely by the stem cell (Lin- CD34+ CD38- CD90+ CD45RA-) by developing a novel genetic approach, tracing all somatic mutations and karyotypic abnormalities back to this population.
Prior to this study, very little was known about the clonal architecture of CMML. By performing detailed phenotypic, functional, molecular and genetic analysis of patients with CMML, we were able to demonstrate that the most likely candidate driver cell in these patients was also the stem cell rather than any of the down-stream progenitors.
Currently, effective therapeutic strategies for MDS or CMML are very limited. Allogeneic stem cell transplantation is the only potential cure and not suitable for most patients. Cancer stem cells, including MDS stem cells are known to be highly quiescent and selectively resistant to therapy. Having demonstrated that both MDS and CMML were driven by stem cells, we developed a novel therapeutic targeting strategy. Using the thrombopoietin receptor agonist, Romiplostim, we were able to activate stem cells and enhance their subsequent sensitivity to chemotherapy dramatically. This approach may facilitate improved remission rates and prevent cancer stem cell driven relapse in many diseases.
Application of magnetic resonance for non-invasive phenotyping of mice with altered metabolism
Keywords: heart failure
MRS
mouse
ATP
adenine nucleotides
ribose
creatine
MRI
AGAT

Changes in myocardial energetics have been implicated in the pathophysiology of heart failure (HF). However, the precise contribution of creatine (Cr) / phosphocreatine (PCr) / creatine kinase (CK) energy buffer and transfer remains unclear. The aim of this thesis was to study the effects on murine cardiac function of both impairment and enhancement of creatine metabolism.
In order to longitudinally follow the cause and effect relationship of myocardial creatine concentration, a non-invasive method of quantification was required. Cardiac Cr levels measured in vivo by 1H-MRS were therefore compared with gold-standard invasive HPLC and found to correlate over a wide-range (r2=0.91). 1H-MRS was reproducible for measuring Cr levels in the heart, brain, and skeletal muscle.
The cardiac phenotype of a novel model of creatine depletion, the AGAT-/- mouse, was characterized using in vivo MRI, 1H-MRS and LV catheterisation, under conditions of gradually reducing Cr concentrations; zero Cr; and attempted phenotype rescue with dietary Cr. For the first time in the heart, the rate of Cr turnover was quantified (~3 % per day) and demonstrated that cardiac function was preserved even when creatine levels reduced by ~70-90%. Total absence of myocardial Cr induced impairment of inotropic and lusitropic cardiac function and reduced inotropic reserve. Cardiac dysfunction was only partially rescued by replenishment of the Cr pool, suggesting this to be a consequence of long-term adaptations to chronic low Cr.
Finally, we tested the hypothesis that combined elevation of myocardial creatine and ribose would be beneficial in a mouse model of chronic HF by increasing cardiac energy availability. Despite an increase in myocardial ribose concentration, this did not prevent loss of total adenine nucleotides (TAN), and there was no improvement in post-infarct LV remodeling or function. Future studies are needed to explore alternative approaches for maintaining TAN in combination with total creatine.
Citizens at war: the experience of the Great War in Essex, 1914-1918
Keywords: civilians
morale
World War I
recruitment
Essex
Great Britain

This thesis examines the experiences and attitudes of civilians in Essex during the First World War, 1914-1918. Through these it explores the reasons for people’s continued support for the war and how public discourse shaped conceptions of the war’s purpose and course and what sacrifices were needed and acceptable in pursuit of victory. This combination kept the war comprehensible and enabled people to continue to support it.
Vital to getting a picture of how the war was understood is an account of the role of the local elites that sought to shape popular knowledge and attitudes about the war. The narratives of the war, the discourse of sacrifice, and elites’ roles evolved with events at home and at the front.
Chapter 1 deals with the initial reactions to the war and growing acceptance of the major war narratives. The second and third chapters address two of their major features: attitudes towards the enemy and volunteering for the armed forces. The fourth chapter addresses the changes to the war's narratives and ideas of sacrifice as casualties and hardships increased from 1916, while Chapter 5 provides an in-depth case study of local military service tribunals. The final chapter deals with the crises of 1917-18, which covered both the expected course of the war and the image of equal sacrifice, and how local and national elites overcame these problems.
The successful depiction of the Great War as necessary, just, winnable, and fought against an evil enemy allowed civilians to accept sacrifices in order to win. An evolving discourse of sacrifice framed what was expected of and acceptable to civilians. Local elites played an essential role: advocating sacrifice and endurance for the national cause while also working to ensure that sacrifices were minimised and borne equally. This combination of framing the war and mitigating its effects was vital in maintaining civilian support for the war effort.
Boundary layer transition in hypersonic flows
Keywords: supersonic
transition
boundary layer
turbulent
turbulence
hypersonic
gun tunnel
tripped flow
Ludwieg tube
scramjet
flat plate
laminar

Boundary layers are an important consideration in hypersonic vehicle design, influencing both heat transfer and drag characteristics. It is advantageous to be able to control precisely where turbulent transition in boundary layers occurs in the intake of a scramjet, the propulsion mechanism of choice for hypersonic air-breathing engines.
The present study examined transition on a flat plate representing a scramjet intake at hypersonic velocities. Experiments were carried out with Mach 5.1 flow over the plate, to provide an analogy with the intake design for the air breathing propulsion system of the Long-Term Advanced Propulsion Concepts and Technologies (LAPCAT) Mach 8 configuration. The flat plate was fabricated and mounted in the Oxford University Gun Tunnel, instrumented with thin film heat transfer gauges to measure the heat transfer rate as a proxy for the existence of turbulence in the flow over each gauge. MATLAB simulations of turbulent spot formation and propagation were created in order to design a suitable array of heat-transfer gauges and the necessary analysis software to characterize spots in terms of spreading angle and trailing- and leading-edge velocities. This analysis software was demonstrated on the simulated turbulent spot signals.
The flat plate was tested using the Gun Tunnel’s Ludwieg Tube with Isentropic Compression (LICH) mode both with smooth and cylindrically “tripped” leading edges. Heat transfer data were processed and analyzed. While individual turbulent spots were not detected in the experimental data, the average heat transfer data for the smooth edge can clearly be seen to move from laminar, nearly matching the Pohlhausen laminar result for Stanton number in terms of Reynolds number at hypersonic velocities, to turbulent transition by the end of the plate. The tripped heat transfer data seem to indicate the rapid onset of transition and overshoot, followed by a re-laminarization and ultimately convergence with the untripped result as both approach the Van Driest turbulent solution for Stanton number in terms of Reynolds number at hypersonic velocities.