VictorJuiz/thesis huggingface dataset:
Extrusion processing of chocolate crumb paste

This project considers the co-rotating twin screw extrusion of a confectionery paste comprising powdered proteins, sugars, water and fats. As is the case with many food industry products, this process has been developed experimentally with little quantitative understanding of how variations in processing conditions influence the formation of the extrudate. A variety of techniques have therefore been developed to characterise and quantify the dispersive mixing, distributive mixing and rheological flow properties of this complex, multiphase, viscoelastic, unstable material. These techniques have then been utilised in a pilot plant extruder study of the mechanics of mixing and paste formation during extrusion, considering the influence of both processing conditions and screw profile. The internal evolution of paste microstructure has been successfully tracked along the length of screw profile using dead-stop extractions of the screws.
A rigorous off-line assessment of shear yield strength behaviour using cone penetrometry has shown the use of conventional off-line rheometers to be unviable due to rapid post extrusion hardening. This highlighted the need for an in-line rheological measurement technique for continuous extrusion analysis where the extruded material is severely time dependent and not extractable. In pursuit of this, a novel arrangement of bender elements is proposed and trialled, to rapidly characterise material parameters of viscoelastic pastes. A second technique looking to extend the application of shear wave interface reflection to multiphase pastes is also trialled.
A novel analysis of thermogravimetric data (TGA) has generated a viable index of distributive mixing, suitable for use on complex multi-component materials where thermal decomposition temperatures of the components are not well defined. Quantitative image analysis of pastes using scanning electron microscopy (SEM), optical microscopy protein staining and a novel application of multiphoton microscopy (MPM) have been used to visualise paste microstructure and quantify dispersive mixing.
From the pilot plant extruder study, the application of these techniques was successful in mapping the evolution of paste mixing and the resulting microstructure, as well as identifying key differences between pastes mixed by twin screw extrusion and batch mixing.

Keywords: Shear Wave Rheometry
Pastes
Thermogravimetric Analysis
Cone Penetrometry
Food Engineering
Twin Screw Extrusion
Multiphoton Microscopy
Mixing Analysis
Foods
Advisor: Martin, P
Martin, C
Becoming global race women: the travels and networks of black female activist-intellectuals, 1920-1966

This thesis explores how a group of Caribbean and African American activist-intellectuals became global race women in the early to mid twentieth century. Global race women, is the term I use to describe middle-class, public women of African ancestry who were committed to aiding the progress of the darker races, especially, but not exclusively, blacks. They frequently travelled, both literally and imaginatively, which allowed them to develop a cosmopolitan sensibility, forge multiracial coalitions with Africans, Asians, Caribbeans, and Europeans, and practice transnational activism. Their globalism saw them identify, think, and act on a global basis that was tied to the global African diaspora. But it did not distract them from the local considerations that shaped their politics. For global race women, the global and the local were intertwined.
This study centres on three protagonists including the Jamaican writer and broadcaster Una Marson (1905-1965), the Martiniquan journalist Paulette Nardal (1896-1985), and the American anthropologist and writer Eslanda Robeson (1895-1965). While the three women did not call themselves global race women, they embodied its characteristics. Their identities as global race women saw them grapple with the race and gender problem as a global phenomenon. They participated in race-based civil rights organisations, anti-fascist campaigns, the League of Nations, United Nations, feminist, and women’s groups. By embracing a range of strategies, they forged networks that crossed ideological, religious, racial, and gendered divisions. The original contribution this thesis makes is the argument that physical or imagined travel and overlapping global social and professional networks were critical to the practice of becoming a global race woman. The significance of this work lays in its placing of black women at the centre of globally connected conversations about cosmopolitanism, anti-fascism, transnational activism, feminism, the end of empires, and the long global freedom struggle between the 1920s and 1960s.

Keywords: black activist-intellectuals travel
networks
Advisor: Tuck, S
Keire, M
Bristol society in the later eighteenth century with special reference to the handling by computer of fragmentary historical sources

There has been little interest in eighteenth century urban history in England and particularly in the significance of patterns of urban social structure during the transition from a traditional to a modern society. One reason for this is the intractable and fragmentary nature of the sources for this precensus period. In this study three types of source, a town directory, a Parliamentary Poll Book and the city rate and national tax returns for Bristol in 1774/5, were collated using nominal record linkage techniques to give a body of information which covered 80% of the city's heads of household. With the use of this database and various computer techniques occupation, sex, wealth, place of residence and voting allegiance were analysed. The results suggest that a professional or leisured suburban group was by this date well established in distinct areas of the city. The supremacy of the traditional élite, the overseas merchants, was challenged by this group, although the merchants themselves were in part joining the suburban dwellers. Poorer Bristolians still concentrated in dockside parishes and in parts of the city which were becoming increasingly unfashionable and homogeneous as the richer men moved out, though this process was not very far advanced and there was still a degree of mixing in the older city parishes. The economic structure of the city was changing with increased emphasis on services, professions and distribution. This increased disparities in wealth within the city and between the city and its hinterland and gave the ability to the rich to further their isolation from the poor by moving to the suburbs. The 1774 election pointed to the continuing importance of traditional influences (here of religion) In society, but also confirmed suggestions that the professions and distributors were drawing away from the mass of the populace. A revision of previous interpretations of the nature of Bristol society is necessary to accommodate this growing and important group - the emergent middle class. The thesis shows that a comprehensive computer-based study can make usable dubious sources (in particular fiscal records) and use them to revise interpretations of English urban communities at this date.
A growth and management model for coniferous plantations in East Africa

A mathematical model is presented for growth and yield of Cupressus lusitanica, Pinus radiata and Pinus patula growing in the highlands of Kenya, Uganda, Tanzania, and Malawi, based on permanent sample plot data. Stand dominant height is predicted by a log/reciprocal function of age and site Index. Initial diameter distributions are predicted by spacing at a dominant height of 7 metres and generated by a Weibull function. The diameter distribution of stems is simulated by a vector of 10 cumulative percentiles which are incremented over each growth period by a function based on relative basal area, dominant height, and tree dominance. Relative basal area is defined in terms of maximum basal area, which. itself is modelled by a Chapman-Richards function in terms of dominant height. Dominance is defined as the ratio of tree diameter to stand dominant diameter. Thinnings are simulated by a novel and efficient algorithm that takes some trees from all size classes but is biassed to the smaller stems, although the degree of bias varies with thinning intensity. Tree volumes are determined by a new tree taper function using a quadratic/cosine model of relative height and relative sectional area. An algorithm is presented based on the taper function for subdividing stand volume into classes determined by log diameter and length. Validation of the model showed that diameter increment and height prediction, as well as the thinning routine were very accurate over a wide range of stand conditions; but the taper function was biassed towards underestimation of larger sizes and required re-fitting by a suitable method of weighting, whilst the initial distribution estimation required an additional variable to account for some of the variation occurring in practice. Two computer programs and a subroutine library are presented in the Appendix. VYTL-2 is a program to produce variable yield tables; whilst PYMOD is a forecasting program for multicompartment forests.
Examining Sen's capability approach to development as guiding theory for development policy

The purpose of this dissertation is to examine to what extent Sen's freedom-centred view of development, with its existing theoretical foundations, offers sufficient theoretical insights for guiding development policies towards the enhancement of human freedoms.
The theoretical part of the dissertation focuses on the three foundational building stones of Sen's freedom-centred view of development. First, the capability approach sets the evaluation space of development in the capabilities that people have reason to choose and value, but by doing so, it is argued that Sen's capability approach contains tensions between human freedom and human well-being that can be loosened by thickening this evaluation space with a substantial view of human well-being. Second, the capability approach views individual agency as central in development, but because of the socio-historical dimension of human freedom and agency, it is argued that concepts of collective capabilities and of socio-historical agency are more central in promoting human freedoms. Third, promoting human freedoms cannot be dissociated from democratic policy-making. But because the link between the two is not necessary, it is argued that the capability approach's consequentialist evaluation of human well-being will have to be thickened by a procedural evaluation which assesses the exercise of political freedom through certain normative principles of decision-making.
The empirical part of the thesis illustrates these theoretical arguments through the analysis of two case studies, Costa Rica and the Dominican Republic. The case studies particularly point to a country's socio-historical agency, or collective capability in promoting human well-being, through socio-historical narratives. These narratives assess a country's collective capability in promoting human freedoms by looking at the country's socio-historical reality, and how its members have appropriated that reality in the course of the country's history, opening up or closing down opportunities for realising policy decisions towards the removal of unfreedoms.

Advisor: Stewart, F
Italy and the League of Nations: nationalism and internationalism, 1922-1935

This thesis investigates the relationship between Fascist Italy and the League of Nations (LoN) during the interwar period, with a particular focus on the years from 1922 to 1935. This relationship was contradictory, shifting from moments of active collaboration to moments of open disagreement. The existing historiography on the Italian membership of the League has not reflected this oscillation in policy, focusing disproportionally on the crises Italy caused at the League. However, Fascist Italy remained in the League for more than 15 years, ranking as the third-largest power, and was fully engaged in the institution's work. This dissertation investigates the dynamics that developed between Fascist Italy and the LoN through a systematic study of the Italians involved. In so doing, it contributes to the historiography of the LoN and of the Italian foreign policy in the interwar period. The thesis argues that there was more to the Italian membership of the LoN than the Ethiopian crisis. It reveals the extent of the Italian presence and activity in the institution from the beginning, and demonstrates that the organization was more important to the Italian government than previously recognized. Membership of the League was essential to guarantee Italy international legitimation and recognition. Through an active appropriation of internationalism, the Italian government hoped to obtain practical benefits in the colonial sphere. The thesis uncovers the depth and variety of interactions between nationalism and internationalism in the case of Italy and the League, establishing that they did not oppose each other but rather interacted. This dissertation illustrates the complexity of being an Italian working in the League, as well as the grey areas between nationalism and internationalism evident within individual experiences. Finally, it shows the continuity of actors and expertise in Italy's international cooperation between the interwar and the post-1945 period.

Keywords: internationalism
History of International Organizations
League of Nations (History)
Fascist Italy
International Relations (20th century)
Europe-Foreign Relations-1918-1945
nationalism
Advisor: Clavin, P
Evaluation of a potential vaccine against hyperinvasive serogroup B Neisseria meningitidis by assessment of the effects of surface-expressed Opacity-associated proteins on the immune system

Neisseria meningitidis causes 500,000 cases of meningitis and septicaemia annually worldwide, with a mortality rate of approximately 10%. Most disease in developed countries is caused by serogroup B infection, against which there is no universal vaccine. Opa proteins are major meningococcal outer membrane proteins, and a limited number of Opa variants have been associated with hyperinvasive serogroup B meningococci, suggesting their use as a potential novel vaccine. Immunisation of mice with recombinant Opa elicited high levels of meningococcal-specific serum bactericidal antibody (SBA), demonstrating proof in principle of this approach. Opa proteins mediate bacterial adherence to host cells and modulate human cellular immunity, and there are conflicting data regarding their effects on CD4⁺ T cells.
opa genes from N. meningitidis strain H44/76 were cloned into the plasmid vector pBluescript, disrupted using antibiotic resistance cassettes and transformed into H44/76 to sequentially disrupt the four opa genes. This produced a unique panel of 15 isogenic Opa-deficient strains, including an Opa-negative strain, which enabled investigation of the immunomodulatory role of surface-expressed Opa proteins.
There was no consistent effect of Opa expressed on the surface of OMVs and inactivated bacteria on CD4⁺ T cells, with significant heterogeneity of responses between individuals. The rate of Opa phase variation was between 10-3 and 10-4, and increased 180-fold following transformation of bacteria with unrelated DNA.
These data support further investigation of Opa as a potential meningococcal vaccine component, and highlight the importance of host and bacterial factors in the development of OMV vaccines.

Keywords: Neisseria meningitidis
serogroup B
vaccine
T cell
homologous recombination
phase variation
Opa protein
Advisor: Pollard, AJ
Spectroscopic analysis of primeval galaxy candidates

This thesis presents spectroscopic observations of z ≥ 7 galaxy candidates in the Hubble Ultra Deep Field, which were selected with HST WFC3 imaging, using the Lyman-Break technique. Four z-band (z ≈ 7) dropout galaxies were targeted with Gemini/GNIRS, one z-band dropout galaxy and three Y -band (z ≈ 8 − 9) dropout galaxies with VLT/XSHOOTER, and 22 z-band dropouts with VLT/FORS2, where 15 of the latter are strong candidates. No evidence of Lyman-α emission is found, and the upper limits on the Lyman-α flux and the broad-band magnitudes are used to constrain the rest-frame equivalent widths for this line emission. Amongst the targeted objects, observations were made of HUDF.YD3, a relatively bright Y -band dropout galaxy likely to be at z ≈ 8 − 9 on the basis of its colours in the HST ACS and WFC3 images. Lehnert et al. (2010) observed this galaxy using the VLT/SINFONI integral field spectrograph and claim that it exhibits Lyman-α emission at z = 8.55. In observations of this object described in this thesis, which were made with VLT/XSHOOTER and Subaru/MOIRCS, this line was not reproduced despite the expected signal in the combined MOIRCS & XSHOOTER data being 5σ. Hence it appears unlikely that the reported Lyman-α line emission at z > 8 is real.
Accounting for incomplete spectral coverage, in total (across all spectro- graphs) 9.63 z-band dropouts and 1.15 Y -band dropouts are surveyed to a Lyman-α rest-frame Equivalent Width better than 75 ̊A. A model where the fraction of high rest-frame equivalent width emitters follows the trend seen at z = 3−6.5 is inconsistent with these non-detections at z = 7−9 at a confidence level of ∼ 91%, which may indicate that a significant neutral HI fraction (χHI) in the intergalactic medium suppresses the Lyman-α line at z > 7. In particular, the lack of detection of Lyman-α emission in this spectroscopy is compared with results at lower redshift by Stark et al. (2010), who derive a mapping between Lyman-α fractions and χHI based on radiative transfer simulations by McQuinn et al. (2007). These results suggest a lower limit of χHI ~ 0.5.

Keywords: high-redshift universe
astrophysics
Lyman-alpha emission
galaxy formation
physics
starburst galaxies
reionisation
observational cosmology
galaxy evolution
high-redshift galaxies
galaxies
Advisor: Bunker, A
Blood oxygen level dependent imaging of cerebral mesostructure

In this thesis I investigate blood oxygen level-dependent (BOLD) MRI methods of imaging the cerebral blood volume (CBV), mean vessel radius and oxygen extraction fraction (OEF). Through the investigation of these individual techniques a new framework is proposed for the simultaneous measurement of all three parameters, providing a comprehensive assay of the cerebral mesostructure.
A new method for the segmentation of blood filled voxels from the sagittal sinus is presented. The implemented method is completely automated and thus removes user bias in voxel selection. The segmentation method is used in a volunteer study to calculate CBV from a hyperoxic challenge according to an existing technique. CBV measurements from this study are found to be significantly overestimated. However, a new derivation of the hyperoxic CBV equation is presented that reveals significant errors in the original method, corresponding to the observed overestimates in CBV. Modelling studies are presented that investigate the discrepancy in reported BOLD MRI measurement of mean vessel size. A significant degree of the variation in the results is found to arise from the noise sensitivity of the analysis methods. This finding is confirmed with experimental data from healthy volunteers that show good agreement with the modelling studies.
Comprehensive modelling of the BOLD response to hyperoxia and hypercapnia is used to develop a new framework for OEF calculation. The new method is based on the calibration of the BOLD signal response against a change in intravascular susceptibility. The OEF calculation is extended by introducing a spin-echo readout into the acquisition scheme. This extension of the acquisition scheme provides a further independent probe of the BOLD signal, enabling the simultaneous calculation of the mean vessel size and CBV. The new framework is shown to provide OEF and vessel size estimates over a wider range of physiological parameters, providing greater scope for the clinical implementation of these techniques.

Keywords: MRI
Oxygen Metabolism
Advisor: Bulte, D
Subdegree growth rates of infinite primitive permutation groups

If G is a group acting on a set Ω, and α, β ∈ Ω, the directed graph whose vertex set is Ω and whose edge set is the orbit (α, β)G is called an orbital graph of G. These graphs have many uses in permutation group theory. A graph Γ is said to be primitive if its automorphism group acts primitively on its vertex set, and is said to have connectivity one if there is a vertex α such that the graph Γ\{α} is not connected. A half-line in Γ is a one-way infinite path in Γ. The ends of a locally finite graph Γ are equivalence classes on the set of half-lines: two half-lines lie in the same end if there exist infinitely many disjoint paths between them.
A complete characterisation of the primitive undirected graphs with connectivity one is already known. We give a complete characterisation in the directed case. This enables us to show that if G is a primitive permutation group with a locally finite orbital graph with more than one end, then G has a connectivity-one orbital graph Γ, and that this graph is essentially unique. Through the application of this result we are able to determine both the structure of G, and its action on the end space of Γ.
If α ∈ Ω, the orbits of the stabiliser Gα are called the α-suborbits of G. The size of an α-suborbit is called a subdegree. If all subdegrees of an infinite primitive group G are finite, Adeleke and Neumann claim one may enumerate them in a non-decreasing sequence (mr). They conjecture that the growth of the sequence (mr) is extremal when G acts distance transitively on a locally finite graph; that is, for all natural numbers m the stabiliser in G of any vertex α permutes the vertices lying at distance m from α transitively. They also conjecture that for any primitive group G possessing a finite self-paired suborbit of size m there might exist a number c which perhaps depends upon G, perhaps only on m, such that mr ≤ c(m-2)r-1. We show their questions are poorly posed, as there exist primitive groups possessing at least two distinct subdegrees, each occurring infinitely often. The subdegrees of such groups cannot be enumerated as claimed. We give a revised definition of subdegree enumeration and growth, and show that under these new definitions their conjecture is true for groups exhibiting exponential subdegree growth above a prescribed bound.

Advisor: Neumann, P