VictorJuiz/thesis huggingface dataset:
Tuning the electrical and optical properties of two dimensional materials

The emergence of 2D materials inspires the pursuit of all-2D materials based devices which are predicted to outperform those with conventional architectures and materials. To achieve this goal, thorough understanding of the fundamental electrical and optical properties of 2D materials separately and the ability to manipulate these properties via external modulation methods are essential.
Graphene can perform as transparent electrodes, yet suffering from its high sheet resistance. It was demonstrated that it can be greatly reduced via doping iron (III) chloride solution onto graphene film with high optical transmission at visible range if an optimal dopant solution concentration was employed. Doping with nanoscale spatial resolution was then achieved with the help of aberration-corrected transmission electron micro- scope, allowing in-situ observation of the atomic structures of doped regions, which possess unique properties predicted by DFT calculations.
Transition metal dichalcogenides (TMDCs) can perform as active materials due to their sizeable bandgap. Therefore, the focus of this thesis then shifted to the investigation of WS2 . Three different methods were employed to alter the optical properties of WS2 . Firstly, the photoluminescence (PL) of WS2 presents layer dependent response towards lateral electric field, with PL quenching in monolayer and PL enhancement in bilayer. The results of temperature dependent PL measurement ruled out the joule heating effect. A possible mechanism based on the inter-valley electron transfer induced recombination pathways modification was then proposed.

Advisor: Warner, J
The rise of a manuscript culture and the textualization of discourse in early China

This thesis analyses a change in the ways people composed and engaged with texts during the Warring States (481-221 BCE) period in Early China. It examines changes in the textual sphere as a result of an emergent manuscript culture, that is to say, the increased spread and reliance on manuscript texts for the communication of ideas. This shift moved away from the predominantly oral, commemorative, and ritual use of text in earlier periods, and provided key elements that would function in the text based discourse of the early empires. It influenced the way text across a variety of genres of writing was used and understood, structured and composed, and how it was collected and combined to form new arguments.
I focus on texts from the Documents 書, and Odes 詩 genres, in addition to philosophical texts dealing with the past, and collections of sayings and arguments dealing with questions from cosmological to ethical issues. These materials form the mainstay of Warring States intellectual discourse, and exemplify the following textual developments: 1) the rise of collecting materials into compilations; 2) the emergence of genre classification; 3) the development of new authorship functions, 3) an increase in textual structuring and the integration of lore about the past, 4) the development of commentarial traditions, 5) the emergence of an explicit, self-reflexive understanding of writing and transmission, 6) advances in material structuring of manuscript-texts that interrelate form and content.
The analysis is based primarily on excavated materials not edited during the early empires, and engages with comparative and interdisciplinary theory. It argues against models solely based on transmitted sources, which explained Warring States developments as a response to socio-political contexts. Instead, it posits developments in the textual culture itself as a necessary condition to explain the changes in intellectual discourse of the period.

Keywords: Manuscript Studies
Early China
Warring States
Manuscript Culture
Advisor: Meyer, D
Field induced assembly  of paramagnetic colloidal particles

The assembly of paramagnetic colloidal particles in the presence of an external magnetic field is studied with optical video microscopy. The first half of this thesis concerns chain formation, which occurs at relatively low surface coverages, and the second half concerns network formation, happening at relatively high surface coverages. First, we study the irreversible aggregation kinetics of two-dimensional paramagnetic colloidal particles in the presence of an in-plane magnetic field at low packing fractions. In particular, we study the packing fraction and field dependence of the mean cluster size. We compare experimental results to the predicted scalings for diffusion limited and deterministic aggregation respectively. It is shown that the aggregation kinetics for our experimental system is consistent with a deterministic mechanism. Next, we establish a direct relation between the distribution of coordination numbers of particles and the mean cluster size using simple statistical considerations. Empirically, a shifted geometric distribution of cluster sizes is observed, consistent with a discrete compound Poisson growth process. This is corroborated by simulations in which the initial spatial distribution of particles is controlled. The generality of our approach is demonstrated by applying it to a more complex clustering processe in two dimensions. Then we investigate the structural properties of magnetorheological networks. The size distributions, orientational ordering and spatial distribution of voids is investigated and compared to random fiber theory. In the fiber phase, the segment length distribution is characterised, as well as the distributions of fiber widths and orientations. These network properties are interrelated such that the entire growth process of fibrous networks can be summarised in terms of a single length scale. We follow this length scale in time for a range of fields and concentrations, investigating the dynamics of the network coarsening. Finally, we propose a link between random fiber theory and the coordination number statistics of particles that make up the network. We show that the fraction of particles with a coordination number less than 6 is key in quantitatively predicting the area of voids. Additionally, we show that clusters of 2 and 4 coordinate particles correspond to segments of the network, 6 coordinate particles represent a population of filled voids, and that singly coordinated particles are a sensitive diagnostic tool to probe the initial aggregation mechanism.

Advisor: Dullens, R
Aarts, D
Goblet cell differentiation in colorectal cancer

Colorectal stem cells give rise to three cell types in the colorectal crypt: enterocytes, enteroendocrince cells and goblet cells. In colorectal cancer this stem cell differentiation is dysregulated and absence of differentiation usually confers a worse prognosis for the patient. In order to understand goblet cell differentiation in colorectal cancer we first investigated novel goblet cell markers. REG4 was found as a marker through examination of our microarray data on 96 colorectal cell lines and confirmed through flow cytometry and immunohistochemistry. Dll4 was also examined as a potential goblet cell marker but instead stained a separate population of cells that may prove to either influence goblet cell differentiation or be goblet cell progenitors. We then examined the roles of goblet cell differentiation regulators such as Notch and the homeobox genes CDX1 and CDX2 in colorectal cell lines. Treatment of colorectal cell lines with inhibitors of the Notch pathway, including the γ-secretase inhibitor DBZ and anti-Dll4, increased the number of goblet cells. Knockdown of CDX1 and CDX2 decreased the number of goblet cells in goblet cell producing cell lines. Further research will elucidate the mechanisms by which these regulators influence differentiation, which could yield a treatment for colorectal cancer; inducing goblet cell differentiation and abating further tumor growth.

Advisor: Bodmer, W
Inequalities in child development in Peru: evidence about its origins and the effects of policy interventions on parental behaviour

This thesis examines two topics related to the prevalence of unequal developmental outcomes among children of different socioeconomic backgrounds in Peru. The first topic focuses on the origins of these inequalities by measuring the relative importance of school and early childhood influences for the emergence of cognitive development gaps between urban and rural children. I use rich longitudinal information on cognitive achievement, household and school characteristics, and a novel decomposition strategy. Results reveal that observable school influences occurring between ages 6 and 8, account for a significant share (around 35% and no less than 28%) of the difference in cognitive skill. The share attributable to differences in the early childhood environment is important but no larger than 50%. I also discuss how the proposed decomposition strategy compares to other linear decomposition methods and why it is less prone to biases than those employed so far in the literature. The second topic is related to the effects and mechanisms behind early childhood development interventions that seek to improve the home environment through a change in parental behaviour. I use data on parenting practices and caregiver beliefs regarding the importance of parent-child interactions collected from the control and treatment groups of families randomized for the evaluation of a home-visiting programme recently launched at scale in rural Peru. I find that this intervention produced a positive effect on the quality of the home environment (d = 0.5; p &LT; 0.01) and shifted caregiver behaviour increasing their participation in educational play activities with the child (d = 0.3; p &LT; 0.01). I also explore the constraints that limit caregivers' behavioural change. I find that treatment effects are not significant among the poorest caregivers and that they exhibit a positive wealth gradient. Further, I find evidence suggesting that caregiver beliefs condition their responses to treatment.

Advisor: Dercon, S
Rolleston, C
The coastal interface: Lesbos and Anatolia

This thesis is a regional history of Lesbos and the adjacent regions of Troas and Aiolis in NW Turkey during Greco-Roman antiquity. This area represents a zone of transition between the Mediterranean and inland Asia Minor, and therefore provides us with a case study of how regions which lie at the margins or beyond the theoretical framework of Horden and Purcell's The Corrupting Sea (2000) function. Rather than defining the area of study simply in terms of physical geography, I instead argue that we can identify a region which I term the coastal interface that is characterized by the overlapping and intermingling dynamics of the maritime and terrestrial worlds. This zone of transition can extend out to sea to include nearby islands which are orientated towards the mainland, for example Lesbos in the case of my thesis, or equally it can stretch inland up river valleys or along other routes of communication to places which, although out of sight of the sea, were nevertheless profoundly influenced by their connection to the maritime world. The chapters of the thesis aim to demonstrate that the concept of the coastal interface can help illuminate the social and economic history of communities living within this region, with Chapters 1-3 focusing on the Troad and Chapters 4-7 looking at Lesbos. The subjects covered include Hellenistic Ilion and the koinon of Athena Ilias (Chapter 1), Theophrastos as a source for the social and economic history of the forests of Mt. Ida (Chapter 2), large-scale state-directed horse breeding in the middle Skamander valley (Chapter 3), Mytilene's peraia in coastal Anatolia from the seventh century down to 427 (Chapter 4), Mytilene's minting of billon and electrum coinage in the fifth century (Chapter 5), the refoundation of the Lesbian koinon in the early second century BC (Chapter 6), and the Aiolian aspect of Mytilenaian identity in the first centuries BC and AD (Chapter 7).

Advisor: Thonemann, P
An action research investigation into peer and self-assessment strategies and their effectiveness in enhancing student learning in GCSE Geography

The aim of the research is to examine the use of peer and self-assessment strategies (PASA) within the Geography classroom. It adopts a broad definition of PASA which considers any student-led reflections about work quality to be examples of PASA.
PASA strategies are frequently heralded in the literature as having the potential to have significant long term impacts on student learning and student agency. Despite this, there is very little use of such strategies within the school in this study and very little understanding of teacher and student perspectives of such an approach to formative assessment.
This study begins with a literature review to critically evaluate the evidence for the effects of PASA on student learning. It examines the conditions under which such practices can enhance student learning and explores some of the subject-specific issues concerning the use of PASA in Geography.
The study took the form of two action cycles; working collaboratively with two other Geography teachers over a term to introduce Year 9 students to PASA activities. The student and teacher responses to these action cycles were interpreted, allowing short term implications for the action research to be acted upon as well as identifying longer term implications for my understanding of the issue and subsequent practice.
The study’s findings indicate that the improvement purpose of the feedback provided in PASA was not valued by the students in the study. However, it appeared that PASA did enhance students understanding of the anatomy of quality in Geography with the result that they had a clearer picture of progression. It seemed that this anatomy of quality was found to be more effective when it was subject-specific rather than specific to the actual phenomena being taught. The research also reflected the dynamic interconnection between the personal and school-related level and policy-level factors. In this study students' personal experiences of assessment had not taught them that their own views or opinions on their work are valid. Whilst incorporation of PASA at a classroom level is possible, the findings indicate that unless this is supported by wider school and policy level factors, it is unlikely that students would be receptive to their use.

Keywords: MLT
Geography
MLT2016
Stranded assets and environment-related risk

This thesis represents the first comprehensive attempt at providing conceptual and scholarly coherence to the topic of stranded assets and the environment. Over the last five years the topic has risen up the agenda and has become of significant interest to scholars and practitioners alike, as it has influenced a number of pressing issues facing investors, companies, policymakers, regulators, and civil society in relation to global environmental change.
The thesis reveals how the topic developed and emerged, notably through a unique first-person account based on autoethnography and close dialogue. Four self- contained papers demonstrate the wide applicability of stranded assets, and further existing, relatively well-developed literatures (namely carbon budgets and stranded costs) and also two much less developed literatures (namely the calibration of climate policy to minimise stranded assets and policy mechanisms to quickly and efficiently strand assets).
Though a significant amount has been written on stranded assets over a short period, there remain significant gaps in the literature. The thesis identifies substantial research opportunities, particularly to better connect our understanding of physical and societal environment-related risks; to improve our knowledge of perception and behaviour in relation to the creation and management of stranded assets; to expand the scope of work into new sectors and geographies; and to place stranded assets in an appropriate historical perspective.
Stranded assets is, if anything, a geographical concept. The thesis makes the case for economic geography as the disciplinary home for stranded assets. The sub-discipline can both contribute to the development of stranded assets as a scholarly endeavour and itself benefit from interacting with a topic that intersects with some of the most pressing contemporary issues related to environmental sustainability.

Keywords: stranded assets
Advisor: Clark, G
A study on the effect of grain boundary elements on polycrystalline superalloys

Polycrystalline nickel-based superalloys substantially derive their mechanical properties from the strength of their grain boundaries. Carbon and boron are the main grain boundary strengthening elements and they play a critical role on the performance of superalloys. However, how these grain boundary elements enhance the mechanical properties of polycrystalline superalloys is not well understood. This thesis presents information about the impact of carbon and boron additions on the mechanical properties of two superalloys suitable for land-based gas turbine applications. New findings with high scientific and industrial relevance that will improve our understanding about the grain boundary elements during the design of new superalloys are presented. High-resolution characterisation methods were used to study the effect of boron on the grain boundary character of a new polycrystalline superalloy. Boron was found to alter substantially the grain boundary character by controlling phase precipitation. Different boron contents were also studied and correlated with the mechanical properties; creep performance was found to vary with boron content. In addition, in-situ studies at elevated temperatures were used to rationalise the effect of boron on improving the mechanical properties of superalloys. The main deformation mechanisms taking place were identified and presented. Finally, the effect of carbides on crack initiation and propagation under complex stress and temperature cycles was studied in detail for a conventional cast superalloy. Carbides were found to have a detrimental effect by serving as crack initiation sites on superalloys for power generation applications. In overall, the findings suggest that boron rather than carbon is the crucial grain boundary strengthener for superalloys used in industrial gas turbines.

Keywords: superalloys
grain boundaries
Advisor: Reed, R
Effective Professional Learning: An inquiry into the impact of 'collaborative' training interventions on the professional development of teachers in their second year of teaching

Retention of beginning teachers is an ongoing priority in education. In my Research and Development project, I investigated which learning resources beginning teachers most valued in their second year of teaching in order to learn more about how best to support and retain them.
Significant empirical evidence suggested that teacher collaboration could have a positive impact on practice and I therefore decided to introduce a new, collaborative element to an existing programme for teachers in their second year at my school. My research questions were:
1. What is the impact of using 'collaborative' training interventions on professional learning in the second year of teaching?
2. What do second year teachers' view as the most effective learning resources in their second year of teaching?
Five teachers peer-observed each other twice during the year; and offered feedback. Following observations, teachers took part in a semi-structured interview reflecting on their experiences of collaboration. Qualitative methods were chosen in order to collect rich and personalised data.
Findings confirmed that teachers responded positively to collaborative training interventions but not to peer-observations in and of themselves. Findings also supported empirical evidence of the highly individualised nature of support needed for each individual practitioner. Further, a complex interaction of factors impacted significantly on what teachers perceived to be meaningful and useful training.
Implications for future training were found to need to take into account diagnostic, collaborative, reflective and affective elements in order to satisfy the needs of a diverse teacher cohort.

Keywords: MLT2016
MLT
Tetramates as antibacterial and anticancer core scaffolds

This thesis is concerned with the synthesis of small molecules that mimic tetramate- and pyrrolidinone-containing natural products, and the evaluation of their antibacterial and anticancer properties.
Chapter 1 exposes the need for new antibiotics due to the emergence of resistance to current drugs, and it discusses the value of the natural product inspired approach for drug discovery. It also gives an overview of the structure, synthesis and biological properties of the natural products pramanicin and oxazolomycin, both of which contain a pyrrolidinone core.
Chapter 2 describes an efficient synthetic route which allowed the preparation of a library of acyltetramates via Grignard addition to a Weinreb amide. This route was also used to prepare mimics of the acyl chain of pramanicin, comprising dienones and epoxy-enones of different lengths, and of the left-hand segment of oxazolomycin.
In Chapter 3, reduction of the tetramate core of different closely-related systems was performed, and it was found that the diastereochemical outcome could be controlled by appropriate choice of substituents in the bicyclic system. Preparation of reduced acyltetramates was only successful via hydrogenation of the Weinreb amide and subsequent Grignard substitution.
Chapter 4 describes the introduction of β-lactones to pyrrolidinones. Conditions for the selective formation of either spiro- or fused-β-lactones were found, which relied on the activation of the precursor β-hydroxyacid, accessed via N,O-acetal deprotection and ester saponification of the bicyclic systems. Further functionalisation of these analogues to mimic oxazolomycin was thwarted by the instability of some of the intermediates.
Finally, the biological properties of the analogues are discussed in Chapter 5. The antibacterial activity against Gram-negative E. coli and Gram-positive S. aureus was examined using the holeplate method, which showed that the aliphatic lipophilic tetramates were the most potent inhibitors, with selective Gram-positive activity. An anticancer high-content screen was also designed, but only weak activities of the synthesised compounds were observed against four cancer cell lines.

Keywords: antibacterial
Advisor: Moloney, M