VictorJuiz/thesis huggingface dataset:
Measuring and understanding grain boundary properties of engineering ceramics
Keywords: FIB
alumina
microcantilever beams
ceramics
fracture
focussed ion beam
residual stress
microscale testing
silicon nitride

This thesis aims to measure the mechanical properties of ceramics on the microscale using microcantilever beams. Focussed Ion Beam milled triangular cross-sectional beams (approximately 3 x 5 x 20µm) were fractured using a nanoindenter to measure the Young’s modulus, fracture strength, and fracture toughness. By developing the technique with a sapphire bicrystal, it was found that the mechanical properties could be successfully ascertained if correction factors were used. Experiments and theoretical work showed that sapphire and polycrystalline alumina beams undergo moisture assisted sub-critical crack growth when tested in air. Whilst corrections for the Young’s modulus have been previously reported, this is the first reported attempt to correct for the notch tip residual stress and the first to consider sub-critical crack growth.
Once these factors were characterised using the sapphire bicrystal, the technique was applied to a range of different ceramics, such as polycrystalline α-alumina and silicon nitride. These are the first reported direct measurements the grain boundary toughness of these ceramics using microcantilever beams.
The grain boundary toughness was correlated with the macroscopic fracture properties and the characteristics of the ceramic (grain boundary composition, impurities, and fracture mode). Two grades of α-alumina were used and the macro- and micro-scale properties extensively compared. The damage evolution during uniaxial compression of alumina was investigated in depth, and compared to a previous reported microcrack evolution model using the measured grain boundary toughness. Investigation of whether deformation twins formed during loading was undertaken and the phenomenon was shown to not occur.
Moving beyond their mandates? How international organizations are responding to climate change
Keywords: development
displacement
international relations
international organisations
climate change

Inter-governmental organisations (IGOs) are given mandates by states to perform particular tasks: from refugee protection to the management of migration to promoting development. As new global challenges arise, such as climate change, these organisations must decide whether to ignore them or change in response. But what drives inter-governmental organisations to move beyond their mandates, if it is not their member states? International Relations offers a limited account of if and how they will respond to new issue areas. Principal-agent theory treats IGOs as units with fixed preferences to expand and maximise their tasks and scope (Hawkins et al. 2006; Nielson and Tierney 2003; Pollack 2003). Meanwhile, sociological institutionalism argues that IOs are driven by a logic of appropriateness and staff will only support expansion if it fits coherently with their organisational identity and culture (Barnett and Coleman 2005). I build on these two theories and propose that IGO behaviour should be explained by organisational type. IGOs exist along a spectrum from normative to functional ideal-types. Normative IGOs have supervisory status over a body of international law, seek moral legitimacy and follow a logic of appropriateness. Functional IGOs are projectised organisations which seek pragmatic legitimacy and adopt a logic of consequences. I illustrate how IGO type interacts with the status of the new issue area to determine the timing, nature and extent of organisational change. I focus on the responses to climate change of three inter-governmental organisations: the United Nations High Commission for Refugees, a normative organisation; the International Organisation for Migration, a functional organisation; and the United Nations Development Programme, a hybrid organisation. IGO type has important implications for IR scholars and policy-makers as we look to these institutions to provide global solutions to global issues such as climate change, migration, refugees and development.
Commentary on Midrash Rabba in the sixteenth-century: the Or ha-Sekhel of Abraham ben Asher
Keywords: Midrash

The Or ha-Sekhel of Abraham ben Asher (Venice, 1567) is of great importance in the history of the study of midrash because it is the first book in which Genesis Rabba was accompanied by commentaries, one spuriously attributed to Rashi and the other written by Abraham ben Asher himself. The composition of a commentary on a midrash was something of a novelty in the mid-16th-century; immediate precedents are hard to identify. Yet, several such commentaries and a large number of prints of Midrash Rabba were published at this time, suggesting that the status of this ‘anthology of midrashim’ was undergoing a period of transition. The need for a correct text and the explanation of obscure vocabulary was foremost in the minds of interpreters such as Issachar Berman of Poland. However, the increasing importance of midrash in the sermons of the Iberian immigrants to the Ottoman Empire also inspired the composition of more discursive commentaries. The homiletic nature of Abraham ben Asher’s expositions suggests that they should be seen in this context. His incorporation of an earlier commentary falsely attributed to Rashi into the Or ha-Sekhel might be understood as an effort to ground his innovative presentation of Genesis Rabba as a text requiring thorough study and the guidance of learned commentators in the work of Rashi himself. Understanding the way Abraham ben Asher has compiled these texts in the Or ha-Sekhel sheds new light on the pervasive interest in midrash in the 16th-century and the outpouring of commentaries on Midrash Rabba at this time.
Investigation of landslide-induced debris flows by the DEM and CFD
Keywords: Discrete Element Method (DEM)
Computational Fluid Dynamics (CFD)
landslide hazards
dimensional analyses
3D DEM plane strain condition
DEM-CFD coupling
terrestrial / submarine landslides
granular column collapse model

In recent years, the increasing impacts of landslide hazards on human lives and lifeline facilities worldwide has advanced the necessity to find out both economically acceptable and useful techniques to predict the occurrence and destructive power of landslides. Though many projects exist to attain this goal, the current investigation set out to establish an understanding of the initiation and propagation mechanisms of landslides via numerical simulations, so that mitigation strategies to reduce the long-term losses from landslide hazards can be made.
In this research, the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) have been used to investigate the mechanical and hydraulic behaviour of granular materials involved in landslides. The main challenge is to provide rational analyses of large scale landslides via small scale numerical simulations. To solve this problem, dimensional analyses have been performed on a simple granular column collapse model. The influence of governing dimensionless groups on the debris runout distance and deposit height has been studied for the terrestrial and submerged granular flows.
3D DEM investigations of granular flows in plane strain conditions have been performed in this research. The input parameters of the DEM model have been calibrated by the numerical triaxial tests, based on which, the relationships between the microscopic variables and the macroscopic soil strength properties are analysed. Using the simple granular column collapse model, the influences of column aspect ratio, characteristic strain, model size ratio and material internal friction angle on the runout distance and deposit height of granular materials have been examined. Additionally, the deformation and energy evolution of dry granular materials are also discussed. The DEM-CFD coupling model has been employed to study the mechanical and hydraulic behaviour of highly mobilized terrestrial / submarine landslides. This model has been validated via numerical simulations of fluid flow through a porous soil sample and grain batch sedimentations. The simulations of granular flows in the submerged environment have led to some meaningful insights into the flow mechanisms, such as the mobilization of sediments, the generation and dissipation of excess pore water pressures and the evolution of effective stresses.
Overall, this study shows that the proposed numerical tools are capable of modelling the mechanical and hydraulic behaviour of terrestrial and submarine landslides.
Fast iterative solvers for PDE-constrained optimization problems
Keywords: saddle point systems
preconditioning
numerical linear algebra
PDE-constrained optimization

In this thesis, we develop preconditioned iterative methods for the solution of matrix systems arising from PDE-constrained optimization problems. In order to do this, we exploit saddle point theory, as this is the form of the matrix systems we wish to solve. We utilize well-known results on saddle point systems to motivate preconditioners based on effective approximations of the (1,1)-block and Schur complement of the matrices involved. These preconditioners are used in conjunction with suitable iterative solvers, which include MINRES, non-standard Conjugate Gradients, GMRES and BiCG. The solvers we use are selected based on the particular problem and preconditioning strategy employed.
We consider the numerical solution of a range of PDE-constrained optimization problems, namely the distributed control, Neumann boundary control and subdomain control of Poisson's equation, convection-diffusion control, Stokes and Navier-Stokes control, the optimal control of the heat equation, and the optimal control of reaction-diffusion problems arising in chemical processes. Each of these problems has a special structure which we make use of when developing our preconditioners, and specific techniques and approximations are required for each problem. In each case, we motivate and derive our preconditioners, obtain eigenvalue bounds for the preconditioners where relevant, and demonstrate the effectiveness of our strategies through numerical experiments. The goal throughout this work is for our iterative solvers to be feasible and reliable, but also robust with respect to the parameters involved in the problems we consider.
Determining the structures of halogenated marine natural products by total synthesis
Keywords: total synthesis
natural product synthesis
structure determination
synthetic organic chemistry

Elatenyne, a brominated C15 acetogenin isolated from the red Laurencia elata marine algae, was originally assigned a pyranopyran structure. Previous total synthesis of the pyranopyran structure has found this assignment to be incorrect. During this work the revised 2,2’-bifuranyl skeleton of elatenyne was suggested, but this skeleton has 32 possible diastereomers. The most likely diastereomer of elatenyne was predicted using computational 13C NMR chemical shift calculation in combination with the possible stereochemical outcomes from the proposed biosynthesis.
Chapter 1 introduces the structural misassignment of natural products and describes the misassignment of elatenyne as well as a related chloro enyne. The use of computational methods and biosynthetic postulates to aid structure elucidation are also discussed. Chapter 2 describes the first generation synthesis of cross metathesis coupling partners required for the synthesis of elatenyne from D-mannitol.
Chapter 3 describes the completed total synthesis of elatenyne, along with three derivatives and the (E)-isomer of elatenyne; itself a natural product. A comparison of the synthetic data with the isolation data for the natural products is presented, as well as comparison with the synthetic material of Kim and co-workers whose concurrent biomimetic total synthesis is also presented.
Chapter 4 describes the modular nature of the devised synthetic route to access any diastereomer of elatenyne and its application to related 2,2’-bifuranyl natural products.
'Civilising' China: visualising wenming in contemporary Chinese art
Keywords: urbanisation
biopolitics
contemporary China
wenming
civility
digital culture

This study examines how the discourse of wenming (civilisation/civility) has been visualised throughout twentieth century Chinese art, with a particular emphasis on contemporary practice. Originally linked to concepts of modernity and change in the early twentieth century I argue that wenming continues to be of crucial importance in understanding how contemporary China wishes to be seen by the rest of the world. Through a series of close visual readings and case studies I explore how wenming attained considerable saliency as it was invoked to address a range of artistic and political reforms which resulted from China's socioeconomic transformations. Individual chapters focus on the work of Sun Yuan and Peng Yu, Liu Gang, Wang Jin and Ai Weiwei amongst others. Taken together they provide an emic account of artistic praxis that seeks to understand contemporary art from China on its own terms.
The study begins by examining how wenming was visualised in the early twentieth century. It then charts what happened to the term after the founding of the PRC in 1949 and how its appearance in locations such as Taiwan and Hong Kong provide sites of contention and alterity to mainland wenming discourse. It analyses how the bifurcation between material civilisation and spiritual civilisation that gained prominence following the economic reforms of the 1980s reconfigured the visual art of this period. Then, turning to a single art work, it theorises the relationship of wenming to an emerging corporeal politics. Finally, it explores how the discourse of wenming is being visually articulated in contemporary China as a result of these developments and traces its interaction with consumer culture, urbanisation and the politics of the internet.
The celebrity gossip column and newspaper journalism in Britain, 1918-1939
Keywords: National Identity
Celebrity Culture
Class
Popular Print Culture
Gender
Interwar Britain

This thesis analyses the content, tone, form and authorship of the national newspaper gossip column 1918-1939, as a new means through which the qualities of the popular press in this period can be more closely defined. Often dismissed as an example of the sensational, Americanization of early twentieth-century popular culture, the celebrity gossip column has been loosely grouped with the friendly, informal language and bolder formatting of the ‘New Journalism’ of the late nineteenth century and the development of the dramatic ‘human-interest’ stories of ‘everyday life’ in the interwar period (LeMahieu, 1988; Wiener, 1988). Through a comparative study of six newspapers including the Daily Express, Daily Mail and News of the World, I analyse the changing representation of the celebrity subject, and, originally, the shifting character and persona of the gossip columnist. Whereas some historians have analysed the content of newspapers without considering the questions of the newspaper’s production, I analyse newspaper employment records, gossip columnists’ memoirs and their unpublished letters and diaries to define the specific economic, social and cultural circumstances which, I argue, influenced their public portrayal. Also, in examining the unpublished correspondence between editors, proprietors and columnists and the burgeoning print culture of journalistic training manuals and professional memoirs, I provide a history of the press’s professionalization in this period. The national popular press has often been used as a historical source to define national character and national identity in the interwar period (Bland, 2008; Kohn, 1992). By scrutinizing the content and production of the gossip column and particularly the class, behaviour, interactions and subject matter of the columnist, I argue that the gossip column presented a version of ‘Britishness’ that was not so inward-looking and domesticated as so many accounts of interwar Britain suggest.
Neuroprotection gene therapy in retinal degeneration
Keywords: RETINAL DEGENERATION
GENE THERAPY
NEUROPROTECTION
X-linked inhibitor of apoptosis

Retinal degenerative disease, which includes age-related macular degeneration and retinitis pigmentosa, is the main cause of blindness in developed countries. Degeneration of the retinal pigment epithelium (RPE) and photoreceptor cells through apoptosis is believed to be the main mechanism of cell death. X-linked inhibitor of apoptosis (XIAP) is an endogenous anti-apoptotic protein that mediates its effects through the inhibition of caspases - the proteins regulating the final stages of apoptosis. The neuroprotection of XIAP has been demonstrated in various neurodegenerative models. Retinal gene therapy based on adeno-associated virus (AAV) has recently been proven safe and effective in clinical trials of Leber's congenital amaurosis. However, studies are very limited so far about AAV-mediated XIAP effect on degeneration of the RPE and photoreceptor cells.
In this thesis, a comprehensive study of AAV-mediated XIAP was performed in the RPE and photoreceptor degenerative models. First, an oxidative stress model was investigated using H2O2 in a human RPE cell line. Second, AAV2-mediated XIAP conferred marked protection on the RPE cells against H2O2 induced apoptosis. Third, an in vivo analysis using confocal scanning laser ophthalmoscope was applied to the NaIO3 induced retinopathy in two transgenic mice (NRL-GFP and B6TGOPN1LW-EGFP). However, subretinal injection of AAV2-XIAP did not rescue photoreceptor cells in the NaIO3-treated animals. Finally, AAV8-XIAP was tested in a rhodopsin mutant mouse line with retinal degeneration (the Rho-/- B6TGOPN1LW-EGFP mouse) but did not reveal any protection on cone photoreceptors. Overall the work in this thesis indicates a limited protection of AAV-mediated XIAP on the RPE and photoreceptor cells in the degenerative models used. XIAP based gene therapy may be helpful for RPE preservation in atrophic AMD, but it needs further research.
The role of ERAP1 and HLA-B27 in ankylosing spondylitis pathogenesis
Keywords: ERAP1
HLA-B27
Ankylosing Spondylitis

HLA-B27 and ERAP1 are the two strongest predisposing genetic factors to Ankylosing Spondylitis (AS). As a key aminopeptidase in MHC class I presentation, ERAP1 potentially contributes to AS pathogenesis through altering HLA-B27 peptide presentation. In this thesis, I first studied the effect of AS-associated ERAP1 variation on its enzyme activity in vitro. Trimming of two N-terminally extended HLA-B27 epitopes was decreased by K528R mutation; the effect of R725Q was however substrate-dependent. I also investigated the effects of ERAP1 silencing on the repertoire of peptides bound to HLA-B27 and on peptide presentation to Cytotoxic T lymphocytes (CTLs). In both HeLa.B27 and C1R.B27 cells, the proportion of 9mer peptides, the canonical MHC class I peptide length, was decreased by ERAP1 silencing whereas the percentage of longer peptides (11-13mer) was increased. Surprisingly, following ERAP1 silencing, C-terminally extended versions of 9mer and 10mer peptides were readily identified. In both HeLa.B27 and mouse fibroblasts expressing HLA-B27, ERAP1 silencing/knockout reduced recognition by KK10-specific HLA-B27-restricted CTLs following recombinant vaccinia viral infection or transfection with minigenes expressing KK10 precursors. Interestingly, KK10 CTL recognition following extended KK10 minigene transfection was reduced in the presence of the AS protective variant, K528R-ERAP1 compared to wildtype ERAP1. The effects of ERAP1 inhibition (Leucinethiol), silencing (siRNA & shRNA) and introduction in ERAAP-/- cells on cell surface HLA-B27 expression were also studied. My finding validates the role of ERAP1 and HLA-B27 interaction in AS pathogenesis indicated by GWAS. ERAP1 inhibition could potentially be used for treatment in AS and other ERAP1-associated diseases.
Pax terra mariqve: rhetorics of Roman victory, 50 B.C. -  A.D. 14
Keywords: War
Roman Imperialism
Peace
Roman History

This thesis focuses on a short period of time between 50 B.C. to A.D. 14, which is marked by the increased prominence of pax as a central concept within the victory rhetoric of the period. The period is one of immense political and social upheaval and change that was to dictate the power structures of the Roman world, and one of the ways in which this change was conceptualised was through the language of peace.
In this thesis I examine pax as a concept within the Roman empire and as part of an discourse on the nature of Roman imperialism. This examination considers not just the development of pax as a concept over time, but also how it was variously conceptualised and presented to different audiences and in different locations. This focuses the examination of pax on understanding what the term as an expression of Rome’s imperium meant to various peoples within the Roman empire, how it was expressed and for what reasons. As David Mattingly has recently emphasised the nature of Roman imperialism changed radically over time (‘Imperialism, Power, and Identity: Experiencing the Roman Empire’ (2011)). This study of the different rhetorics of peace offers new insight into this changing nature.
Beyond the specific examination of pax as a part of imperial discourse within the late Republic and early Principate, this study raises questions about the way we think about concepts in the ancient world. Rather than talking about a single development or evolution over time, we should rather consider concepts as constantly active and changing in time. Our view of the ancient world and the way in which it was conceptualised should not be a static one, but one where the meaning and value of words give us insights into how individuals and communities expressed and explained changing social and political conditions.
G2 geometry and integrable systems
Keywords: 53C38
Hitchin component
53C07
G2
53C29
parabolic geometry
special Lagrangian
coassociative
Higgs bundles
53C43

We study the Hitchin component in the space of representations of the fundamental group of a Riemann surface into a split real Lie group in the rank 2 case. We prove that such representations are described by a conformal structure and class of Higgs bundle we call cyclic and we show cyclic Higgs bundles correspond to a form of the affine Toda equations. We also relate various real forms of the Toda equations to minimal surfaces in quadrics of arbitrary signature. In the case of the Hitchin component for PSL(3,R) we provide a new proof of the relation to convex RP²-structures and hyperbolic affine spheres. For PSp(4,R) we prove such representations are the monodromy for a special class of projective structure on the unit tangent bundle of the surface. We prove these are isomorphic to the convex-foliated projective structures of Guichard and Wienhard. We elucidate the geometry of generic 2-plane distributions in 5 dimensions, work which traces back to Cartan. Nurowski showed that there is an associated signature (2,3) conformal structure. We clarify this as a relationship between a parabolic geometry associated to the split real form of G₂ and a conformal geometry with holonomy in G₂. Moreover in terms of the conformal geometry we prove this distribution is the bundle of maximal isotropics corresponding to the annihilator of a spinor satisfying the twistor-spinor equation. The moduli space of deformations of a compact coassociative submanifold L in a G₂ manifold is shown to have a natural local embedding as a submanifold of H2(L,R). We consider G2-manifolds with a T^4-action of isomorphisms such that the orbits are coassociative tori and prove a local equivalence to minimal 3-manifolds in R^{3,3} = H²(T⁴,R) with positive induced metric. By studying minimal surfaces in quadrics we show how to construct minimal 3-manifold cones in R^{3,3} and hence G₂-metrics from equations that are a set of affine Toda equations. The relation to semi-flat special Lagrangian fibrations and the Monge-Ampere equation is explained.