VictorJuiz/thesis huggingface dataset:
Volcanism as an active planetary process on Venus
Keywords: Volcanology
Modelling
Venus

Volcanism has been a crucial planetary process in the evolution of Venus, shaping the surface and contributing to the formation of the atmosphere and clouds. Some of the key outstanding questions are whether or not volcanism is active today, and what range of volcanic styles have occurred in the past or may occur in the future. This project uses three methods of investigating these questions. Firstly, computer modelling is used to simulate volcanic processes under Venusian conditions using a steady-state, isothermal, homogeneous flow model. It was found that the addition of CO2 to an H2O-driven eruption reduces the H2O requirement for explosive activity, and that eruptions possible on Venus may be detectable in Venus Express data. Next, radar datasets from both Venus and Earth were investigated with the aim of assessing relationships between differing volcanic deposits on Venus and their likely mode of formation, and using trends in the Earth radar data to inform us of what the Venus observations may be telling us. It was found that, in some cases, regional-scale radar observations may be useful in identifying deposit types, but the data used in the study were insufficient to define a globally applicable deposit identification scheme, pending further study. Finally, mapping and spatial analysis of volcanic features and rifts was performed to evaluate the nature of the interaction of volcanism within the global tectonic environment. Spatial relationships are consistent with aspects of the directional model of Venus' evolution, favouring a shift from globally dispersed, relatively small-scale, volcanism spread randomly across the planetary surface towards a gradually more rift-focused distribution indicative of a corresponding shift in global tectonic regime. These various strands are brought together here in order to contribute to our further understanding of volcanism as a fundamental Venusian planetary process.
Small scale mechanics applied to nuclear materials
Keywords: Micromechanics
Small scale mechanics
Ion Irradiation
Iron
Grain Boundaries
Nuclear Fusion
Elasticity
Nanoindentation

Ion implantation is increasingly used as a cost effective and safe alternative to neutron irradiation in the study of materials for future nuclear applications. However, the micron-sized layers of radiation damage necessitate the use of small scale testing techniques to obtain mechanical properties data from these materials. This thesis explores such techniques, highlighting the relative merits and limitations of nanoindentation, and the deflection of FIB-machined specimens, in a variety of applications.
As a simple starting point, the effect of crystal orientation on nanoindentation hardness and modulus is explored in a pure Fe polycrystal, with selected indents examined further post-test by HR-EBSD and AFM. Hardness in grains with &LT;111&GT; and &LT;110&GT; surface normal directions is found to be &Tilde; 20 % higher (&Tilde; 1.1 GPa) than those with &LT;100&GT; surface normals (&Tilde; 0.95 GPa), whilst no discernible trend is seen for modulus.
A novel L-shaped micro-cantilever technique is developed and used to extract single crystal elastic constants within a single grain of Fe. A computational routine minimising the difference between experimental data and the response of an FE model is used to extract such constants, with a good agreement between experiment and literature found after two runs.
Slip transfer across grain boundaries is studied in unirradiated and ion-irradiated samples using nanoindentation. Grain boundaries in the irradiated specimen show less resistance to slip transfer, and the presence of dislocation bursts associated with the operation of dislocation sources in adjacent grains is reduced compared to the unirradiated sample.
Finally, the effects of size and orientation on plastic properties are examined in FIB-machined micro-cantilevers. Two different functions are used to fit flow stresses evaluated at different maximum strains to beam width, and compared. Cantilevers orientated for multiple slip are observed to have lower flow stresses than those aligned for single slip with a Schmid factor of 0.5.
The work in this thesis highlights the importance of both types of small scale mechanical test in providing information of relevance to candidate materials for nuclear applications. Nanoindentation is able to quickly probe mechanical characteristics, but at the expense of a well-defined stress state under the indenter tip, whereas FIB-machined specimens can provide a simpler stress state to test, for higher costs of time and instrument usage.
Educated youth in Kenya: negotiating waithood by greening livelihoods
Keywords: neoliberal subjectivities
young people
waithood

The burgeoning scholarship on African youth indicates that young people are experiencing difficulties in attaining social adulthood and spend extended time in waithood – a period of economic and job insecurities that is becoming a permanent marker of their youth, affecting their life trajectories and future aspirations (Honwana, 2012; Locke & te Lintelo, 2012). Youth waithood involves navigating precarious conditions arising under neoliberalism and its economic liberalization reforms, and developing new subjectivities resulting from the acquisition of extra skills set, maintaining social networks, and engaging in new political formations (Jeffrey, 2008).
Informed by concepts of neoliberal subjectivities, opportunity spaces, and Bourdieu’s forms of capital, I conducted qualitative research with university students in six public universities, and with educated young farmers in Western, Eastern, and Central regions of Kenya. I investigated how Kenyan youth navigate waithood by occupying new opportunity spaces opened up by student environmentalism and agricultural entrepreneurialism – two areas that have been reconfigured by global discourses of environmental change, green jobs, and agricultural transformation.
My findings show that the occupational aspirations of educated youth were changing to include navigation strategies of portfolio occupations, tarmacking, and side-hustling. Within the new opportunity spaces, these youth realized neoliberal subjectivities that enabled them to garner capitals through self-making, entrepreneurialism, and reworking of elite distinctions. Student environmentalists’ navigation strategies included acquiring environmental knowledge and work experiences; joining networks of environmental professionals; and participating in environmental anti-politics. Educated young farmers embraced ideologies of portfolio occupations and green livelihoods. They also relied on the reconfigurations of gendered identities and the rural-urban divide, competitive individualism, and associational life to rework their occupational aspirations and maintain elite distinctions in society.
In sum, negotiating youth waithood is a complex, intertwined, and uncertain process involving flexibilities and chance opportunities to access, maintain, and utilize capitals. The emergent subjectivities remain insecure, unstable and do not necessarily guarantee exiting waithood.
Public reasoning and reciprocity: reconceptualising accountability in the arm's length governance of emerging biotechnologies in the UK
Keywords: PPI
ethical expertise
expertise
telehealth
QALY
cost effectiveness
sex selection
public consultation
cognitive enhancement
patient and public involvement

In the UK, public access to emerging biotechnologies is largely regulated by three government bodies that operate at arm's length from democratically elected representatives: the Human Fertilisation and Embryology Authority (HFEA), the National Institute for Health and Care Excellence (NICE), and the Medicines and Healthcare Products Regulatory Agency (MHRA). Purposefully situated beyond traditional lines of electoral accountability, how can these independent bodies (commonly referred to as 'quangos') conceptualize and demonstrate their accountability to the public in regulating technically complex and morally controversial technologies? After articulating this general theoretical tension between independent and accountable decision-making in the arm's length context, I illustrate how it generates distinct, practical challenges within the HFEA, NICE and the MHRA.
To navigate this general tension and address its practical ramifications, I invoke political theories of public reason and deliberative democracy, as well as recent attempts to apply these theories to the governance of biotechnologies. Through a critical analysis of these accounts, I articulate a new framework for 'public accountability as reciprocity' in the arm's length context. Its four, process-oriented conditions, of 1) reciprocal reasoning, 2) acceptance of deliberative disagreement, 3) voting, and 4) fostering the means of deliberative resistance, affirm the goal of identifying mutually acceptable reasons for collective decisions, but take seriously the fact that characteristics of emerging biotechnologies will often confound such attempts. Taken together, these conditions provide a more theoretically robust and normatively legitimate approach than existing accounts, notably 'accountability for reasonableness.'
Next, I translate the theoretical claims of this framework into practice, illustrating how its conditions may be fruitfully applied towards the resolution of the practical challenges identified within the HFEA, NICE, and MHRA. In the HFEA, public accountability as reciprocity provides a robust approach to moral reasoning in the body's deliberations and resituates the role of public consultation. In NICE, it suggests a justifiable and properly tailored role for patient involvement in technology appraisals. Finally, in the MHRA, it explains why a growing number of devices defy the institution’s traditional assessments of safety and effectiveness and offers reforms to its regulatory boundaries.
I conclude with a set of policy recommendations for creating and operating arm's length bodies, as well as an account of broader contributions to the literature on public reasoning, the concept of 'ethics expertise,' and the practice of patient and public involvement.
Donkey work: redefining the Democratic Party in an 'age of conservatism,' 1972-1984
Keywords: U.S. Congress
Liberalism
U.S. Democratic Party
U.S. Political History

This thesis argues that much of the political historiography is mistaken in portraying the post-1960s United States as a nation moving inexorably to the right. It also argues that historians should not understand the Democratic Party as being in terminal decline between 1972 and 1984, marginalised by a coalescing conservative Republican majority.
Indeed, taking as its focus the U.S. Congress, this thesis asks why the remarkable resilience of the congressional Democratic Party has been overlooked by historians. It further asks why that resilience did so little to help the party in subsequent years. The Democratic revival in the elections of 1974 and 1976, so often dismissed as a post-Watergate aberration, was in fact an authentic political opportunity that the party failed to exploit. Exploring various Democratic factions within Congress that competed to shape their party's public philosophy, this thesis seeks to show how grander liberal ambitions were often subordinated to the logic of legislative politics and policymaking.
The underlying theme is the unsuitability of Congress as an arena for the discussion and refinement of post-Great Society liberalism. Again and again, the legislature displayed a remarkable facility for undermining iconoclasm and stalling policy experimentation. Institutional reforms in the early 1970s, supposed to reinvigorate the Congress and the congressional Democratic Party, actually succeeded only in intensifying the fragmentation of both. Congressional politics became more entrepreneurial and less party-oriented, leaving legislators with few incentives to look beyond their own political fortunes to the party’s future prospects.
Enduring Democratic strength in Congress meant that Capitol Hill remained at the centre of the party's efforts to reclaim its preeminent position in American politics. The fact that the Democrats never experienced a protracted period of minority status, as the Republicans did during much of the mid-twentieth century, left them ill-equipped and without a powerful incentive to think in broader terms about their party’s mission.
Maximising expected value under axiological uncertainty
Keywords: Decision Theory
Axiology
Moral Philosophy
Moral Uncertainty

The topic of this thesis is axiological uncertainty – the question of how you should evaluate your options if you are uncertain about which axiology is true. As an answer, I defend Expected Value Maximisation (EVM), the view that one option is better than another if and only if it has the greater expected value across axiologies. More precisely, I explore the axiomatic foundations of this view. I employ results from state-dependent utility theory, extend them in various ways and interpret them accordingly, and thus provide axiomatisations of EVM as a theory of axiological uncertainty.
Chapter 1 defends the importance of the problem of axiological uncertainty. Chapter 2 introduces the most basic theorem of this thesis, the Expected Value Theorem. This theorem says that EVM is true if the betterness relation under axiological uncertainty satisfies the von Neumann-Morgenstern axioms and a Pareto condition. I argue that, given certain simplifications and modulo the problem of intertheoretic comparisons, this theorem presents a powerful means to formulate and defend EVM. Chapter 3 then examines the problem of intertheoretic comparisons. I argue that intertheoretic comparisons are generally possible, but that some plausible axiologies may not be comparable in a precise way. The Expected Value Theorem presupposes that all axiologies are comparable in a precise way. So this motivates extending the Expected Value Theorem to make it cover less than fully comparable axiologies. Chapter 4 then examines the concept of a probability distribution over axiologies. In the Expected Value Theorem, this concept figures as a primitive. I argue that we need an account of what it means, and outline and defend an explication for it. Chapter 5 starts to bring together the upshots from the previous three chapters. It extends the Expected Value Theorem by allowing for less than fully comparable axiologies and by dropping the presupposition of probabilities as given primitives. Chapter 6 provides formal appendices.
Irradiation effects on the deformation of oxide dispersion strengthened steels
Keywords: fusion
irradiation
micromechanics
steel
fission
ODS
nanoindentation
ion implantation

This study concerns four high performance structural alloys designed to withstand the extreme temperature and irradiation environment inside fusion and fission fast breeder reactors: two Reduced Activation Ferritic Martensitic (RAFM) steels (Fe-14wt%Cr and a European standard alloy EUROFER97) and two equivalent Oxide Dispersion Strengthened (ODS) steels (Fe-14wt%Cr ODS (CEA ODS) and EUROFER ODS).
Neutron irradiation of the samples was impractical due to timescale and specific handling requirements for radioactive samples. Instead, ion implantation was used to simulate the helium and damage of neutron irradiation. Samples of each alloy were subjected to a range of ion implantations: 75appm He, 2000appm He, 2000appm He + 4.5dpa Fe and 2000appm Ne. The matrix of four materials and five implantation conditions was analysed using the following experimental techniques: nanohardness indentation, Vickers hardness testing, micropillar compression, microcantilever bending, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX).
These techniques were used to compare the properties of the unimplanted materials and their response to implantation. Yield stress (σy) was comparable across hardness testing and microcantilever bending, and consistently showed σy Fe-14wt%Cr &LT; EUROFER &LT; EUROFER ODS &LT; CEA ODS. When subject to helium implantation, 75appm He caused insignificant changes in σy while 2000appm He increased σy in all materials. This increase was most significant in Fe-14wt%Cr due to its low grain boundary density and lack of oxide/carbide particles. The particle dispersions in the other materials act as helium traps, preventing the formation of TEM visible bubbles and reducing the hardening effects of the helium.
Across all results it becomes clear that, although not to the degree of the ODS materials, EUROFER is more radiation resistant than Fe-14wt%Cr. It therefore appears that it is the presence of a complex microstructure including small grains and a distribution of oxide or carbide particles, rather than the specific inclusion of oxide nanoparticles, that provides RAFM steels with superior irradiation resistance properties.
Variety for security: A case study of agricultural, nutritional and dietary diversity among smallholder farmers in Western Kenya
Keywords: rural Kenya
agricultural biodiversity
food and nutrition security

Agricultural biodiversity, commonly referred to as agrobiodiversity, is that part of biodiversity that is geared towards agriculture and food production. Agrobiodiversity is said to contribute much to food and nutrition, but there is lack of data confirming this, particularly from Eastern Africa. To assess the extent of agrobiodiversity on smallholder farms and in local markets and to connect these to food intake and perceptions of food security among smallholder farmers in Western Kenya, the thesis asks four main research questions: (i) What is the extent of food plant diversity in smallholder farms, the bio-physical and socio-economic factors influencing it and the contribution of this diversity to the household's food needs? (ii) What is the relationship between agricultural and dietary diversity? (iii) What linkages are there between agricultural and nutritional diversity? (iv) How does access to agrobiodiversity in local markets contribute to meeting household food needs and what is the extent of smallholder farmers' integration into these markets? Through a combination of focus group discussions, farm and market surveys conducted across three time points, results indicate that: (i) higher food plant species richness is found on farms managed by wealthier and older households. However, these households are not more food secure than the rest, (ii) while there is a lack of a strong relationship between agricultural and dietary diversity, dietary diversity is instead significantly influenced by socio-economic factors including a household's wealth status, ethnicity and education level, (iii) despite a diversity of locally available on-farm and market food species meeting existing macro-and micro-nutrient needs, there is a general lack of understanding of this diversity as food shortage months coincide with a lack of maize despite high availability of a diversity of other foods not only to replace the maize but also to contribute to a diverse diet, (iv) smallholder farmers rely on multiple food sources, with markets mainly for sourcing cereals, fruits and animal source foods. There is also low integration of smallholder farmers as sellers in local markets. Together, the four case studies show interlinkages across food availability, accessibility and utilisation, which when addressed with equal weight, could unlock local agrobiodiversity's potential as a path to food and nutrition security of smallholder farming households.
Mobile phone diffusion and rural healthcare access in India and China
Keywords: qualitative
technology
diffusion
survey
capability approach
grounded theory
health action
mobile phones
sequence analysis
mHealth
low- and middle-income countries
healthcare seeking
quantitative
local innovation
rural
mixed methods
digital divide
health behaviour
satellite-aided sampling
international development
healthcare pathways
China
healthcare
social implications
adoption
health system
India

Three decades of mobile phone diffusion, thousands of mobile-phone-based health projects worldwide ("mHealth"), and tens of thousands of health applications in Apple's iTunes store, but fundamental questions about the effect of phone diffusion on people’s healthcare behaviour remain unanswered. Empirical, theoretical, and methodological gaps in the study of mobile phones and health reinforce each other and lead to simplifying assumptions that mobile phones are a ubiquitous and neutral platform for interventions to improve health and healthcare. This contradicts what we know from the technology adoption literature.
This thesis explores the theoretical link between mobile phone diffusion and healthcare access; develops and tests a new multidimensional indicator of mobile phone adoption; and analyses the effects of phone use on people's healthcare-seeking behaviour. My mixed methods research design—implemented in rural Rajasthan (India) and Gansu (China)—involves qualitative research with 231 participants and primary survey data from 800 persons.
My research yields a qualitatively grounded framework that describes the accessibility and suitability of mobile phones in healthcare-seeking processes, the heterogeneous outcomes of phone use and non-use on healthcare access, and the uneven equity consequences in this process. Quantitative analysis based on the framework finds that mobile phone use in rural India and China increases access to healthcare, but it also invites more complex and delayed health behaviours and the over-use of scarce healthcare resources. Moreover, increasing phone-aided health action threatens to marginalise socio-economically disadvantaged groups further.
I present here the first quantitative evidence on how mobile phone adoption influences healthcare-seeking behaviour. This challenges the common view that mHealth interventions operate on a neutral platform and draws attention to potential targeting, user acceptance, and sustainability problems. The framework and tools developed in this thesis can support policy considerations for health systems to evaluate and address the healthcare implications of mobile phone diffusion.