VictorJuiz/thesis huggingface dataset:
Monolayers of cationic surfactants at the air-water and oil-water interfaces

Monolayers of the cationic surfactant hexadecyltrimethylammonium halide (CTAX, where X = F-, Cl-, Br-, and I-) have been studied at the air-water and oil-water interfaces. At the air-water interface, the effects of the halide counterion and the addition of counterion were investigated. Sum-frequency spectroscopy (SFS), ellipsometry, and surface tensiometry indicated that the counterion changed the efficiency and effectiveness of the surfactant, both decreasing in the order of Br- > Cl- > F-. The addition of salt in the form of 0.1 M KX was found to reduce the cmc but had little effect on the limiting area per molecule attained at the cmc, which increased from 44 Å2 for CTAB to 65 Å2 for CTAC and ca. 94 Å2 for CTAF. Neither SFS nor ellipsometry provided any firm evidence for specific effects of the halide ions on the structure of the surfactant monolayers. For CTAB monolayers in the absence of excess electrolyte, the effect of area per molecule on the sum-frequency (SF) spectra was studied.
Mixed monolayers of CTAB and tetradecane at the air-water interface exhibit a first-order phase transition from a conformationally disordered to a conformationally ordered state as the temperature is lowered. The phase transition occurs ca. 11 °C above the bulk melting point of tetradecane.
A new experimental arrangement is described for acquiring SF spectra from surfactants at the oil-water interface. The key features of this approach are the stabilisation of a thin oil film between a sapphire prism and an aqueous phase, and the use of total internal reflection to enhance the total signal and discriminate against signals from other interfaces in the system. With this new methodology, the first SF vibrational spectra of surfactant monolayers at an alkane-water interface were obtained. Surface tensiometry was used to characterise the monolayers further. The structure of CTAB monolayers at the hexadecane-water interface was determined by SFS and compared with monolayers of CTAB at the air-water interface. At low concentrations, CTAB/hexadecane showed the expected features in the C–H stretching region, characteristic of a conformationally disordered monolayer. As the bulk concentration approached the critical micelle concentration, the spectra changed to one characteristic of a more ordered, upright conformation. Ellipsometric measurements supported this conclusion. This qualitative structural change is not observed in analogous monolayers at the air-water interface or CCl4-water interface, or in surfactant solutions in contact with a hydrophobic solid surface.

Keywords: oil-water interface
sum-frequency spectroscopy
sum-frequency generation
ellipsometry
interfacial tension
interfacial monolayer
surface tension
surfactant monolayer
cationic surfactant
air-water interface
mixed monolayer
Advisor: Bain, C
Enduring challenges of statebuilding: British-led police reforms in Sierra Leone, 1945-1961 and 1998-2007

This study analyzes two British-led police reforms in Sierra Leone from 1945-1961 and 1998-2007, exploring how reinterpretations of sovereignty, security and statehood affected strategies of statebuilding over time. Tracing the effects of reform from the first to the second period, it focuses on three practical questions facing reformers: what kind of coercive capacity the police should be invested with (force); where they should be and for what purposes (territoriality); and in what relation they ought to stand with nonstate policing actors (legitimate authority). A key finding is that reinterpretations of security and sovereignty to center on internal threats and state-society relations served to channel more international attention and resources to police forces in weak states. From a relatively restricted field whose impulses came from policing experiences in other colonies and in Britain, recent post-conflict police reforms were informed by knowledge about economic growth, social mobility and global security. However, strategy was muddled when donors committed to conflicting agendas entered the fray. As a result, the latest reform was profoundly shaped by negotiations of the meaning of key concepts like ‘security’. The second part of the study draws on insights about reform to address debates on intervention and sovereignty. Against the image of Western-led interventions suspending local sovereignty, it is argued that the colonial legacy allowed the Sierra Leonean government to prolong and deepen the recent intervention. Contrary to the image of Sierra Leone’s international relations as exploitative and personalized, the study explores how policing became a field where new and legitimate links with the outside world were established after reform.

Keywords: security
Statebuilding
police
sovereignty
governance
Sierra Leone
Advisor: Hood, C
Anderson, D
Recognition of antigen and superantigen by cytotoxic lymphocytes

Human cytotoxic T lymphocytes (CTL) recognize antigen in the form of short peptide fragments presented by Human Leukocyte Antigen (HLA) class 1 molecules. The HLA B27-restricted CTL response to Influenza A virus is directed against a single nine amino acid epitope within the viral nucleoprotein NP383-391.
Influenza A-specific CTL lines and clones, generated from the peripheral blood of three unrelated individuals, exhibited remarkable fine specificity for NP383-391, failing to recognize synthetic variants containing single amino acid substitutions at positions 1, 4, 7 or 8. The sequences of rearranged T cell receptor (TCR) alpha and beta chain genes showed remarkable conservation of variable and joining gene segment usage, and also of non germline-encoded B chain residues proposed to interact with peptide, even between clones from unrelated individuals. Correlation of fine specificity for peptide with TCR alpha chain usage suggested a possible orientation for the TCR/HLA/peptide ternary complex in this immune response. The finding of restricted TCR usage in the HLA B27-restricted CTL response to influenza A virus has implications for the study and potential therapy of HLA B27 associated autoimmune disease.
The TCR heterodimer from one clone was expressed in a rat basophil cell line and shown to confer specificity for HLA B27 + NP383-391.
Influenza A-specific CTL were also shown to recognize bacterial superantigens in an MHC class II dependent but unrestricted manner. A rapid screening assay for candidate superantigens was developed and used to identify a novel superantigen produced by Clostridium perfringens. This superantigen was found to have a unique specificity for human TCRβ chains.

Advisor: McMichael, A
Unconventional futures: anticipation, materiality, and the market in oil shale development

This thesis offers a political geography of unconventional energy development through a study of a particular fossil fuel resource called oil shale. Having long occupied a critical place in the politics and economy of certain states, most notably in Estonia, oil shale is now widely known as an ‘unconventional’ resource that is yet to become technically possible, commercially viable and socially acceptable to exploit. Following the movement through which oil shale becomes both unconventional and conventional, the thesis traces the resource through a series of geo-scientific, economic and political interventions. This study is based on analysis of technical literature and policy documents along with ethnographic fieldwork, interviews, and site visits conducted in Estonia, Colorado, Utah, Jordan, London and Brussels. Drawing together relational accounts of natural resources in political ecology and economic geography with insights from Science and Technology Studies, this project both contributes to critical research on the carbon economy and to recent debates on the concepts of materiality, anticipation, and marketization in social sciences. The thesis proposes a relational conceptualization of resource materiality, situating oil shale in multiple and conflicting forms which derive from geographically disparate practices in both resource assessment and technological development. The future of oil shale exploitation is not pre-determined by the process of global resource decline, nor is it precluded by international demands to move towards lower-carbon futures. Rather, it is determined through the conjunction of different future-oriented economic and political calculations that are entangled with resource materials and associated technological systems. Developing a non-essentialist account of markets as socio-technically distributed arrangements, the thesis argues that these rival calculations influence the design of market rules for both energy and emissions trading. The thesis concludes that what counts as ‘unconventional’ is not given, but continues to be both created and contested at the same time as it is ‘conventionalized’.

Keywords: materiality
Utah
marketization
energy politics
unconventional oil
oil shale
natural resources
Jordan
futures
Estonia
energy geographies
Advisor: Barry, A
The treatment of emotion in Jane Austen and Charlotte Brontë

(Note: this summary does not exactly follow the physical organisation of the thesis. I expect the reader to read the two appendices between Chapters 1 and 2: this is therefore where I include their arguments below.)
Charlotte Brontë wrote some memorable criticism of Jane Austen. What particularly affronted her was Jane Austen's treatment of emotion. This suggests grounds for comparison. If conducted historically the comparison makes more sense. It also helps to consider the novel as 'conjectural history', i.e. to assign (some) novels not to the category of make- believe (creating imaginary worlds which only make sense if certain conventions are accepted), nor that of lying (evoking possible but partial worlds for consolation), but that of guesswork (considering what might have happened in this world).
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State-society relations and regional role: comparing Egypt and South Africa

The study explains the regional roles of Egypt and South Africa in the last two decades by reference to the state’s relationship with society, a variable that has long been underplayed in international relations and foreign policy literature. It suggests that the different character of this relationship in each country has shaped the opportunities and constraints affecting the foreign policy choices of both the state and societal institutions in the two countries.
The study adopts a cross-disciplinary approach using debates on state capacity and its relationship with regime type in comparative politics and political economy to understand and evaluate the two countries' foreign policies in their respective regions.
After analysing the impact of state-society relationships on the regional role conceptions of the state and societal actors, the study compares the performance of these actors in two case studies; the Palestinian-Israeli conflict in the case of Egypt and the Zimbabwean crisis in the case of South Africa. It concludes that although the role of each state in resolving its respective regional conflict has been less than effective, the post-apartheid democratic dispensation has provided opportunities for South African social forces to play roles that complemented, checked and balanced the role of the state, compared to their Egyptian counterparts.
On the other hand, the soft authoritarian Egyptian state used its role in the Palestinian-Israeli conflict to maintain the international alliances that helped to sustain its domestic control. This constrained the state's foreign policy options. It made marketing peace as 'a strategic choice' and containing resistance movements the priorities of Egypt's intervention in the Palestinian issue. The co-optation of the Egyptian business community and the exclusion of Islamist forces by the state weakened their roles in conflict resolution, depriving the state of tools of effectiveness.
In the case of South Africa, racial politics, the ANC's liberation movement psyche, and the domination of the presidency over foreign policy making have hindered the promotion of NEPAD's principles of democracy and respect for human rights in the case of Zimbabwe. However, South African civil society played a crucial role in supporting its Zimbabwean counterpart, holding the South African state accountable to its foreign policy principles and its democratic institutions, and intervening where the state's role was missing or insufficient.

Keywords: South African Foreign Policy
Egyptian Foreign Policy
Regional Powers
Egyptian Politics
South African Politics
Advisor: Mustapha, AR
Rhetoric or reality?

This thesis explores the recent introduction of restorative justice into the youth justice systeminEngland. Itexaminesthehistoricalandpoliticalcontextfromwhichcurrent youth justice policies have emerged and aims to evaluate how this new system is functioning 'on the ground' several years after being implemented. Specifically, the primary aim of the research is to investigate final warnings and referral orders. The findings are based on an in-depth study of one Youth Offending Team (YOT). The research adopted a predominantly qualitative, case study based method utilizing techniques of observation, informal conversations, formal interviews with the young offenders and their supporters as well as with authority figures who are amongst those responsible for policy and practice in the youth justice system. The substantive chapters of this thesis focus on the delivery of final warnings, referral order panel meetings, victim participation, and the structural, cultural and political influences on YOT practice. This research concludes that at present, restorative practices in England are seriously compromised. However, simply because these programmes experience difficulties, they should not necessarily be considered a failure. The present failures in practice are not related to the philosophical foundation of these programmes or even to the way in which they have been set up. Rather, the current shortcomings in practice are due mostly to a failure of implementation on the part of the YOT. The final warning and referral order programmes, if improved, have the potential to become an effective first encounter with the criminal justice system and to impact positively on many first time offenders.
The cyclical behaviour of wages

In 1938 Dunlop challenged the assertion in the General Theory that wages moved countercyclically. The resulting debate on the cyclical movement of wages deserves study as an episode in the history of economic thought. This is done in chapter 2 which reviews the theoretical issues and chapter 3 which reviews the empirical work.
To understand this history requires some analysis of the meaning and significance of the debate.
At one level the debate can be interpreted as the search for a 'stylised fact'. This is apparently an empirical question and part of the thesis will be concerned to use data for various countries, time-periods, cycle phases, and industries to examine whether there is any systematic cyclical pattern in wage movements.
The conclusion of the empirical analysis is that there is no such empirical regularity.
At a second level the debate was theoretical. The empirical observation that wages moved procyc1ica1ly was thought to falsify a prevailing theory. What is interesting about this debate is the light it sheds on the response of economists to apparent falsification.
A third level of the debate is the issue of inference. Keynes tended to treat theory as prior, attacking 'pseudo natural science procedures'. Keynes was not opposed in principle to statistical work informing theory: although in practice he did not attempt the empirical investigation into cyclical wages for which he called. Thus from a different methodological standpoint Burns and Mitchell criticise the theorist who 'often stops before his work is finished'. Current econometrics would emphasise the need for identifying assumptions before estimates could be used to test hypotheses. In this framework, the implications for theory of any reduced form regularity would be ambiguous in the absence on non-data based identifying assumptions.
This thesis uses the history of the debate and the empirical analysis to illustrate these themes of observation, theory and inference.
Phase and interference phenomena in generalised probabilistic theories

Phase lies at the heart of quantum physics and quantum information theory. A quantum bit is qualitatively different from a classical bit as it allows for the coherent superposition of possibilities, which demonstrate different behaviours depending on the phase between them. These behaviours constitute as interference phenomena, and lie behind the existence of algorithms in quantum computing which are arguably faster than the best classical alternatives. The concept of phase is deeply steeped in the structure of Hilbert spaces: the mathematical framework that underlies quantum theory. What if quantum theory did not hold in all scenarios, or was only a limiting case of some broader theory? In this case, would we still be able to meaningfully talk about phase and interference?
In this thesis, we will adopt an operational generalisation of quantum theory known as the framework of generalised probabilistic theories. We will provide a reasonable definition of phase in this framework. Using this, we shall explore single-particle interferometry set-ups (particularly Mach-Zehnder interferometers): experiments whose output is highly dependent on the phase between the spatially disjoint branches through which a particle might be traversing. By applying physically-motivated locality considerations, we identify the crucial role that the uncertainty principle and its generalisations play in quantum theory as an enabler of non-trivial interference. By taking into account relativity of simultaneity, we will also provide a physical motivation for why standard quantum theory provides the best description of the location of a particle traversing such a system. Finally, we apply our generalised definition of phase in the related context of particle exchange behaviour, and identify a method for classifying post-quantum particles.
All of this will demonstrate that phase between possibilities and its consequences are not uniquely quantum phenomena. Much of the behaviour we might ascribe to phase in quantum theory in fact holds generally true for phase in probabilistic theories.

Keywords: generalised probabilistic theories
theoretical physics
foundations of quantum theory
information theory
quantum physics
Advisor: Vedral, V
Surface-electrode ion traps for scalable quantum computing

The major challenges in trapped-ion quantum computation are to scale up few-ion experiments to many qubits and to improve control techniques so that quantum logic gates can be carried out with higher fidelities. This thesis reports experimental progress in both of these areas. In the early part of the thesis we describe the fabrication of a surface-electrode ion trap, the development of the apparatus and techniques required to operate it and the successful trapping of 40Ca+ ions. Notably we developed methods to control the orientation of the principal axes and to minimise ion micromotion. We propose a repumping scheme that simplifies heating rate measurements for ions with low-lying D levels, and use it to characterise the electric field noise in the trap.
Surface-electrode traps are important because they offer a route to dense integration of electronic and optical control elements using existing microfabrication technology. We explore this scaling route by testing a series of three traps that were microfabricated at Sandia National Laboratories. Investigations of micromotion and charging of the surface by laser beams were carried out and improvements to future traps are suggested. Using one of these traps we also investigated anomalous electrical noise from the electrode surfaces and discovered that it can be reduced by cleaning with a pulsed laser. A factor of two decrease was observed; this represents the first in situ removal of this noise source, an important step towards higher gate fidelities.
In the second half of the thesis we describe the design and construction of an experiment for the purpose of replacing laser-driven multi-qubit quantum logic gates with microwave-driven ones. We investigate magnetic-field-independent hyperfine qubits in 40Ca+ as suitable qubits for this scheme. We make a design study of how best to integrate an ion trap with the microwave conductors required to implement the gate and propose a novel integrated resonant structure. The trap was fabricated and ions were successfully loaded. Single-qubit experiments show that the microwave fields above the trap are in excellent agreement with software simulations. There are good prospects for demonstrating a multi-qubit gate in the near future. We conclude by discussing the possibilities for larger-scale quantum computation by combining microfabricated traps and microwave control.

Keywords: ions
ion trappping
electrode
quantum physics
Advisor: Lucas, D
Scales of variability of atmospheric aerosols

Aerosols have a significant effect on the global radiation budget through their interactions with radiation and clouds. However, estimates of their effect are the dominant source of uncertainty in current estimates of total anthropogenic effect on climate. A major cause of this uncertainty is the high degree of variability of aerosol properties and processes that affect their lifetime. Prediction of the aerosol effect on climate depends on the ability of three-dimensional numerical models to accurately estimate aerosol properties. However, a limitation of traditional grid-based models is their inability to resolve variability on scales smaller than a grid box. Past research has shown that significant aerosol variability exists on scales smaller than these grid-boxes, which can lead to discrepancies between observations and aerosol models.
This thesis uses a synthesis of aerosol observations, global climate model (GCM) data, and a new aerosol modelling technique implemented within a regional-scale model to quantify the important scales of aerosol variability and the extent to which different sub-grid scale processes contribute to discrepancies in aerosol modelling.
Analysis of black carbon (BC) plumes from aircraft observations shows that BC plumes represent a large portion of total BC mass and typically exist on scales of 65{ 100 km. Comparison of observed plume scales to those simulated by GCMs at multiple resolutions show that GCMs overestimate the scales of along- ight-track variability by 64% at the highest resolution. Variability is shown to be greater near sources than in remote regions, indicating that models may benefit from higher resolutions in regions of high emissions. Additionally, GCMs at all resolutions show higher variability in the latitudinal direction than the longitudinal direction, suggesting that capturing latitudinal variability may result in greater improvements in aerosol modelling.
This work additionally presents a novel technique to allow one to isolate the effect of aerosol variability from other sources of variability within the model. Processes most affected by neglecting aerosol sub-grid variability are gas-phase chemistry and aerosol uptake of water through the aerosol/gas equilibrium reactions. The inherent non-linearities in these processes result in large changes in aerosol parameters when aerosol and gaseous species are artificially mixed over large spatial scales. These changes in aerosol and gas concentrations are exaggerated by convective transport, which transports these altered concentrations to altitudes where their effect is more pronounced. Future aerosol model development should focus on accounting for the effect of sub-grid variability on these processes at global scales in order to improve model predictions of the aerosol effect on climate.

Keywords: aerosol variability
aerosol
Advisor: Stier, P