VictorJuiz/thesis huggingface dataset:
Numerical modelling of tunnelling processes for assessment of damage to buildings
Keywords: settlement
tunnelling

The development and implementation of a complex numerical model for the determination of the damage to masonry buildings resulting from tunnelling settlements is described in this thesis. The current methods of damage prediction do not, in general, take into account the stiffness and weight of the surface structure. The model addresses this deficiency by explicit inclusion of the structure. Three-dimensional finite elements are used to model the ground with a non-linear, elasto-plastic soil model based on kinematic hardening. Tunnel linings are modelled using a novel overlapping elastic shell element: volume loss being simulated by shrinkage of linings coincidentally with excavation. Structures are modelled as collections of facades comprised of plane stress elements using a non-linear material model for masonry, similar to elastic-no tension. In developing the three-dimensional model, its two-dimensional counterpart is also studied. While the beam and shell elements used for linings (in two- and three-dimensions respectively) have the advantage of no rotational degrees of freedom the need to model boundary conditions at the element stiffness level complicates implementation. Tests using the shell elements show them to be satisfactory for the purpose of modelling tunnel linings. Results from a small number of analyses are given for construction of a straight tunnel beneath simple masonry structures. It is shown that the effect of the building on settlements depends heavily on its location in plan with respect to the tunnel axis. Predictions of crack patterns using the model for these analyses show that facades which the tunnel passes under first are less damaged than those later in the excavation sequence. Both of these conclusions serve to demonstrate that the problem can only be realistically modelled using three-dimensional methods. At present, however, the computer resources required to run the three-dimensional model are considerable.
Molecular mechanisms of premature ageing in a worm model of human Werner syndrome
Keywords: Ageing
Werner syndrome
genetics
genomic instability
RecQ helicase
C. elegans
longevity

Investigating the biological basis of ageing is both fascinating and medically relevant, as we strive to understand both how organisms age, and how our knowledge might be put to good use in an increasingly long-lived human population. Despite the complexity of ageing biology, it is very striking that longevity, in a wide variety of organisms, can be modified by manipulating single genes. In this thesis, I investigate phenotypes associated with mutations in C. elegans homologues of human WRN, the gene mutated in the progeroid Werner syndrome (WS).
Mutant phenotypes in the worm recapitulate aspects of the pathophysiology observed in WS patients, including premature ageing, genomic instability, and sensitivity to DNA damaging agents. wrn-1 overexpression, on the other hand, appears to enhance longevity, suggesting that wrn-1 acts as a bona fide anti-gerontogene. The combination of wrn-1 mutations with mutation in the worm p53 homologue, cep-1, unexpectedly triggers a novel and very striking enhanced lifespan and healthspan phenotype, termed synthetic super-viability (SSV). The SSV phenotype is modulated by various environmental inputs such as temperature stress.
The data presented here can be incorporated into a model in which stress sensing (involving p53) is the crucial determinant of longevity outcomes. Several theories of ageing incorporate the idea that 'that which does not kill us, makes us stronger' - encapsulated in a biological sense in the idea of hormesis, a physiological shift in response to stress. Here, this hypothesis is expanded to include the notion that intrinsic responses to stress may themselves act to limit lifespan - too much of a good thing can be bad.
Semiconductor colloidal quantum dots for photovoltaic applications
Keywords: photovoltaic
PbS
colloidal quantum dots

This thesis studies lead suphide (PbS) colloidal quantum dots and their photovoltaic applications.
Different sizes of PbS QDs were synthesised and characterised using absorption spectroscopy and transmission electron microscopes. PbS QD Schottky junction devices were fabricated with AM1.5 power conversion efficiency up to 1.8 %. The Schottky junction geometry limits the device performance. A semiconductor heterojunction using ZnO as an electron acceptor was built and the device efficiency increased to 3%. By studying the light absorption and charge extraction profile of the bilayer device, the absorber layer has a charge extraction dead zone which is beyond the reach of the built-in electric field. Therefore, strategies to create a QD bulk heterojunction were considered to address this issue by distributing the junction interface throughout the absorber layer. However, the charge separation mechanism of the QD heterojunction is not clearly understood: whether it operates as an excitonic or a depleted p-n junction, as the junction operating mechanism determines the scale of phase separation in the bulk morphology. This study shows a transitional behaviour of the PbS/ZnO heterojunction from excitonic to depletion by increasing the doping density of ZnO.
To utilise the excitonic mechanism, a PbS/ZnO nanocrystal bulk heterojunction was created by blending the two nanocrystals in solution such that a large interface between the two materials could facilitate fast exciton dissociation. However, the devices show poor performance due to a coarse morphology and formation of germinate pairs. To create a bulk heterojunction where a built-in electric field could assist the charge separation, a TiO2 porous structure with the pore size matching with the depletion width was fabricated and successfully in-filled by PbS QDs. The porous device produces 5.7% power conversion efficiency, among one of the highest in literature. The enhancement comes from increased light absorption and suppression of charge recombination.
British, Chinese, and Tibetan representations of the Mission to Tibet of 1904
Keywords: 1904
Younghusband
Mission
Tibet
China

This thesis presents and analyses Chinese, Tibetan, and British sources relating to the British Mission to Tibet of 1904. It balances accounts provided by the British officers and men with modern Chinese sources. It analyses both polarised sides of the history, whilst remaining critical of all sources.
British historical accounts analysed in chapter one are balanced with Chinese narratives that present the Mission as an invasion of the Motherland and its unity. Chapter two examines the role of propaganda in modern China, and how different media are used to guide the Tibetan and Chinese populations’ understanding of their history and nation.
Chapters three and four provide an original translation of Bod kyi rig gnas lo rgyus dpyad gzhi’i rgyu cha bdams bsgrigs, a textbook written from a Chinese nationalistic perspective. The introductory chapter providing the Chinese narrative of the build-up to the Mission is studied in chapter three, and chapter four analyses the bloody advance into Tibet.
The translation and analysis in chapter five of the letters of the Dalai Lama to the King of Nepal, the Tongsa Pönlop, and the Chögyal of Sikkim place the Mission in pan-Himalayan context, and show how the Tibetan Government sought to counter the Mission. It is the first study to provide a historical Tibetan perspective of events.
Chapter six analyses the divisive issue of looting during the Mission. It examines the psychology of those who looted Tibet, and the role the items taken play in shaping the image of Tibet in the West. Modern Chinese propaganda sources from the new media are analysed in chapter seven, and demonstrate how they have been used to compliment and propagate the established narrative. The conclusions analyse the impact of the Mission, and the lessons that may be learnt for those that play the ‘New Great Game.’
The Qiyan in the early Abbasid period
Keywords: classical arabic
oriental
slavery
middle eastern

The thesis deals with the legal status of the qiy̅an as slaves in Islam; describes their nationalities, education and training as singers, instrumentalists and versifiers. It considers their place in the cultural life of the host society. A substantial part of their poetry with particular attention to some of the leading figures is reproduced in translation. A review of that poetry is included, showing the bulk of it to consist of clever epigrams exchanged in public or semi-public maj̅alis, bearing the hallmark of virtuosity and social jousting or party games. Another theme is that the introduction of the qiy̅an into the Abbasid cultural life led to the development of elegiac-erotic poetry. A parallel review of the musical scene, with special reference to some leading exponents, shows the influence of the qiy̅an in the development of new “popular”, unconventional styles of singing. The institution of the qiy̅an in all its artistic manifestations is viewed as essentially a business catering for men in pursuit of pleasure: caliphs, aristocrats and, most commonly, the class of cultured well-to-do chancery scribes. The bulk of the poetry which the established men poets composed in praise of the qiy̅an is seen as publicity material, and substantially produced to commission. The effect of the qiy̅an on the free-born women of their age, as well as historically, is considered; and some comparison is drawn between them as poets and singers. By way of further comparison the geisha and the hetaira of Ancient Greece are alluded to. A chapter is devoted to the decline and fall of the qiy̅an institution in the East and its partial transfer to Arab Spain.
The contribution of new radiocarbon dating pre-treatment techniques to understanding the Middle to Upper Palaeolithic transition in Iberia
Keywords: Paleolithic
Archaeology
Neanderthal
Aurignacian
Mousterian
Palaeolithic
Radiocarbon

In the last ten years it has become apparent that the radiocarbon dating method can significantly underestimate the age of samples > 25 ka BP because routine pre-treatment protocols may not remove sufficient contaminants. In response, new pre-treatment protocols have been proposed, and two in particular, ultrafiltration of bone collagen and ABOx-SC of charcoal, show promise. This thesis has tested whether these methods effectively remove contaminants without adding carbon in the laboratory. Subsequently it used them, alongside careful selection of humanly modified material and Bayesian statistical analysis, to test the radiocarbon-based chronology of the Iberian Middle to Upper Palaeolithic transition.
Both protocols were found to effectively remove environmental contaminants, but add small amounts of laboratory-derived carbon. Using known age standards, a correction has been calculated for the ultrafiltration protocol to counter the effect of the laboratory-derived carbon. A similar correction could not be made for the ABOx-SC protocol due to uncertainties in the age of the standards and underlying chemical processes. However, the effect of such contamination did not have a significant effect on the chronologies developed for the sites examined in this thesis.
96 new radiocarbon dates have been obtained from the Iberian Middle to Upper Palaeolithic transition. A further 50 dates recovered from the literature and are regarded as reliable. The most alarming finding of this thesis is that routine pre-treatment protocols may cause dates to be underestimated by more than 10 ka 14C years. The implication of offsets of this magnitude in Iberia is significant: whereas a prolonged survival of Neanderthals south of the Ebro valley has been observed in the published dataset, this study could not replicate such ages. Preservation did not allow the arrival of anatomically modern humans to be dated in the south. However, using typological arguments and the chronology constructed for the north of the Peninsula, it is unlikely that they were present in this region before 38,080 – 36,680 cal BP (95% probability). This implies a temporal gap of at least 4,490 – 12,740 cal years, although it is unclear whether this is due to taphonomic factors or is a real period of abandonment. This pattern contrasts to northern areas of the Peninsula where the Aurignacian appears at 42,330 – 40,980 cal BP, shortly postdating the start of the Châtelperronian and end of the Mousterian.
It is hoped that the chronology produced will warn against the use of radiocarbon dates produced using poor pre-treatment protocols and has laid the foundations from which a more accurate and more precise chronology can be built in the future.
The influence of invariant natural killer T cells on myeloid-derived suppressor cell generation and function
Keywords: iNKT
Myeloid-derived Suppressor Cells

The absence of invariant Natural Killer T cells (iNKT cells) in mice infected with Influenza A virus (flu) has previously been shown to augment the expansion of Myeloid-derived suppressor cells (MDSCs), a bone marrow derived population that powerfully suppress the development of viral and tumor immune responses. Moreover, iNKT cell adoptive transfer into flu-infected mice has been shown to abolish the expansion and flu-induced suppressive activity of the MDSCs in a CD1d- and CD40-dependent manner. However, the mechanisms by which this relatively small subset of T cells influence myelopoiesis and MDSC differentiation remain largely unknown.
In this manuscript we firstly better define the MDSCs found in flu-infection as IL-10-secreting neutrophils that can suppress T cell proliferation. We then go further to show that the flu-induced ability to suppress T cells is acquired as early as the level of the Granulocyte-Macrophage Progenitors (GMPs) in the bone marrow and that iNKT cells can not only abrogate the suppressive activity of the IL-10-secreting neutrophils in the periphery but also that of the GMPs by a direct CD1d-dependent GCSF-mediated crosstalk.
MDSC expansion has previously been shown to be associated with the expression of the myeloid-related protein S100A9, and the mechanism of action of granulocytic-MDSCs shown to be ARG1-dependent. We built upon both these findings to show that iNKT cells influence the expansion and function of the MDSCs in part by regulating S100A9 and ARG1 expression. Following this we then showed for the first time that the acute phase protein Serum Amyloid A (SAA), shown to increase during flu-infection, has a dual reciprocal role: having the ability to up-regulate S100A9 and ARG1 in myeloid cells and differentiate IL-10-secreting suppressive neutrophils, while simultaneously facilitating the ability of the MDSCs to crosstalk with iNKT cells in a CD1d-dependent GCSF-mediated manner to abrogate the SAA-induced suppressive activity.
All together the data highlights the complexity of the immune response and the role iNKT cells play in influencing the differentiation of MDSCs during demand-driven myelopoiesis. More importantly however, it further affirms that research into harnessing the immunomodulatory capacity of iNKT cells remains an exciting prospect in bolstering future vaccination strategies and should continue to be pursued.
Axiomatic studies of truth
Keywords: logic
Proof theory
philosophy of language
Theory of truth

In contemporary formal theory of truth, model-theoretic and non-classical approaches have been dominant. I rather pursue the so-called classical axiomatic approaches toward truth and my dissertation begins by arguing for the classical axiomatic approach and against the others. The classical axiomatic approach inevitably leads to abandonment of the nave conception of truth and revision of the basic principles of truth derived from that nave conception such as the full T-schema. In the absence of the general guiding principles based on that nave conception, we need to conduct tedious but down-to-earth eld works' of various theories of truth by examining and comparing them from various points of view in searching for satisfactory theories of truth. As such attempt, I raise two new criteria for comparison of truth theories, make a proof-theoretic study of them in connection to the foundation of mathematics.
Organic Brønsted acid-catalysed enantioselective N-acyliminium cyclisation cascades
Keywords: organocatalysis
Bronsted
enantioselective
cascade
acid
phosphoric
binol
indole
asymmetric
N-acyliminium
cyclisation

This thesis concerns the development of the first BINOL phosphoric acid (BPA) catalysed enantioselective N-acyliminium cyclisation reactions and their incorporation into domino sequences that allow for the construction of architecturally complex enantioenriched polycycles in a single step from easily accessible starting materials. More specifically, this thesis deals with the discovery of a BPA-catalysed enantioselective N-acyliminium cyclisation cascade of enol lactones and tryptamines. Its extension to a doubly catalysed process involving gold(I) to cycloisomerise alkynoic acids and a BPA to effect the enantioselective N-acyliminium cyclisation is presented. In addition, the exploitation of this method in highly diastereo- and enantioselective N-acyliminium cyclisations of oxoacids and tryptamines and in a site isolated base-catalysed Michael addition / acid-catalysed N-acyliminium cyclisation cascade is described. A study on the proposed mechanism and model for the origin of enantioselectivity is discussed, based on experimental data and a computational study. As a separate part of our programme, the development of a new class of stronger Brønsted acids, chiral benzenesulphonic acids, is described. The optimisation of the synthetic routes as well as the synthesis of a library of acids is presented and their assessment in precedented reactions is discussed.
Stochastic agent-based modelling for reality
Keywords: discrete choice
agent-based model
National Park

This D.Phil. thesis develops a new agent-based simulation model to improve the results of analysis, which solely uses discrete choice modelling, as well as to analyse the effects of a road user charging scheme for the Upper Derwent Valley in the Peak District National Park. The advantages of discrete choice analysis are well known. However, results with these conventional conventional approaches, which conduct analysis solely with discrete choice models, can be biased if interaction and learning effects are significant. The Minority Game, in which agents try to choose the option of the minority side, is an appropriate tool to deal with these problems. The situation in the Upper Derwent Valley can be explained with economic game theories and the Minority Game. The two approaches mutually help to analyse the situation in the Upper Derwent Valley leading to the development of a stochastic Minority Game. The stochastic Minority Game was tested with an online game (questionnaire), which was played 3,886 times by response in all around the world. The practical part of this thesis examines the components of the stochastic Minority Game with the data collected around the Upper Derwent Valley. The main data was collected using a stated preference survey. Overall, 700 questionnaires were distributed and 323 of them were returned (i.e. a return rate of 46.1 %). In the practical part, the agent-based model has four sub modules: 1) Multinomial mixed logit model for mode choice, 2) Binary logit model for parking location choice, 3) Markov queue model for parking network, and 4) the Minority Game for parking congestion and learning. This simulation model produces comprehensive outputs including mode choices, congestion levels, and user utilities. The results show that the road user charging scheme reduces car demand in the Upper Derwent Valley and ensures a reduction in congestion at the parking areas. The model also shows that an exemption will increase the utilities of elderly visitors without substantially sacrificing those of younger visitors. In conclusion, the simulation model demonstrated that oversimplification in conventional approaches solely using discrete choice models gave significant biases when real world problems were analysed.
Advanced optoelectronic characterisation of solar cells
Keywords: impedance spectroscopy
polymer solar cells
quantum dot solar cells
solar cells

Optoelectronic characterisation techniques are assessed in their application to three solar cell systems.
Charge injection barriers are found in PbS/ZnO colloidal quantum dot solar cells through the use of temperature dependent current-voltage and capacitance-voltage measurements. The injection barriers are shown to complicate the Mott-Schottky capacitance analysis which determines built-in bias and doping density. A model that incorporates depletion capacitance and a constant capacitance arising from the injection barriers is given to explain the Mott-Schottky plots. The junction mechanism at the PbS/ZnO interface is found to transition from excitonic to p-n behaviour based on the amount of UV photodoping the cell has received. External quantum efficiency analysis at different photodoping times reveals a growing charge collection region within the material, demonstrating the shift to p-n behaviour. This is further supported by the observance of depletion capacitance behaviour after, but not before, UV photodoping.
Defects within GaAs cells containing InAs quantum dots are found to enhance the sub-bandgap performance of the cell using external quantum efficiency analysis. This is verified by illuminated current-voltage analysis using a 1000 nm high pass optical filter to block photons of larger energy than the bandgap. Using capacitance-voltage analysis, high temperature rapid thermal annealing is shown to induce defects in dilute nitride cells, which explains the drop in open circuit voltage compared to lower temperature annealed cells.
The doping level of polymer solar cells exposed to air is found to increase with continued exposure using Mott-Schottky capacitance analysis. Current-voltage measurements show the formation of an Al2O3 barrier layer at the polymer/aluminium interface. The usefulness of capacitance-voltage measurements to probe the polymer/fullerene interface is investigated in thermally evaporated thiophene/C60 cells.