VictorJuiz/thesis huggingface dataset:
The properties of nitrogen in silicon
Keywords: dislocation
nitrogen
diffusion
silicon

The behaviour of nitrogen in silicon is investigated using the dislocation unlocking technique. Specimens containing well-ordered arrays of dislocations are isothermally annealed for a controlled duration, during which nitrogen segregates to and pins the dislocations. The stress required to unlock the dislocations is then measured by three-point bending at elevated temperature. By analysing the dependence of this unlocking stress on anneal duration and temperature, information about nitrogen's transport and interaction with dislocations can be deduced. Experiments are performed at anneal temperatures of 500 - 1050C using float-zone silicon with [N] = 2x10^15 cm^-3. The results are analysed to give an expression for nitrogen's effective diffusivity of D = 173,000 exp(-3.24eV/kT)cm^2 s^-1 in the 500 - 750C range, showing for the first time that nitrogen transport at low temperatures behaves in the same way as measured at higher temperatures by other groups using secondary ion mass spectrometry. If analysed in terms of monomer-dimer dissociative transport, the results give a nitrogen monomer diffusivity of D_1 = 28 exp(-(1.1 to 1.4 eV)/kT) cm^2 s^-1, which is similar to that found by another analysis in the literature. The measurements also show that nitrogen's dislocation locking strength measured at 550C is dependent on anneal temperature, peaking at 600 - 700C and falling towards zero above 1000C. The dislocation unlocking technique itself is also investigated and characterized. It is found that the measured unlocking stress is dependent on the three-point bend duration, falling with increasing duration. Analysis of these results in terms of the theory of release of dislocations from pinning points indicates that nitrogen dislocation locking is likely to be by an atomic species. This effect also has implications for the results of previous nitrogen dislocation unlocking experiments, and the technique has been modified so that a standardised set of conditions is used for every test. Other measurements show that nitrogen's dislocation locking effect is lessened by the presence of transition metal contamination, and that dislocation velocity in silicon may be affected by the nitrogen present in the material. A modified dislocation unlocking technique is developed to measure dislocation locking from near-surface ion-implanted impurities. Results from heavily N-implanted silicon show that nitrogen implantation can provide additional dislocation locking strength to that already given by the oxygen in the material. The scale of the dislocation locking effect in these experiments may provide evidence that nitrogen's effective diffusivity is reduced at high concentrations, indicating that nitrogen transport may be by a dissociative mechanism.
The statuettes and amulets of Thonis-Heracleion
Keywords: Delta
lead
votives
underwater
statuettes
Egyptian
cult
bronzes

This study catalogues and analyses 329 statuettes and amulets from Thonis- Heracleion, a sunken city off the coast of Egypt that flourished between the 7th and 2nd centuries BC. This is the first study of votive statuettes and amulets from the Late and Ptolemaic Periods that presents a comprehensive corpus from a single site, complete with detailed catalogue entries and photographs. Although some of the most exceptional pieces were previously published in an exhibition catalogue, the majority are unpublished and it is the first time they have been studied and viewed as a whole.
The material includes not only Egyptian-style bronzes, which are typical dedications of this period, but also a range of other materials including lead, terracotta, faience, and limestone. Some figures are represented in foreign style and attest to a small hellenized community at the site. By viewing multiple categories of votive material laterally and in context, important conclusions about cultural interactions and cult practice at Thonis-Heracleion come to light.
Chapter One details the find context of the statuettes and amulets, followed by a discussion of their types and the cults to which they attest in Chapter 2. Chapter 3 outlines the objects’ primary functions and demonstrates the ways that lead and bronze were utilised differently. Chapter 4 focuses on bronze and lead production methods, particularly methods of replicable production that are indicative of technological exchange with other Mediterranean cultures. Finally, in Chapter 5, I look at how the votives reflect the cultural community at Thonis-Heracleion, and how they compare to others at sites throughout Egypt. Each chapter highlights how the archaeological context informs us about cultural interactions between Egyptians and Greeks and about the dynamics of cult practice at a Delta site in the Late and Ptolemaic Periods.
The Middle Eastern novel in English: literary transnationalism after orientalism
Keywords: English Literature
Middle Eastern Literature
Postcolonial Studies
World Literature

This thesis focuses on the production, circulation, and reception of contemporary Middle Eastern literatures in Britain and the United States. I'm particularly interested in the novel form, and in assessing how both translated Middle Eastern novels and anglophone novels by migrant writers engage with dominant Anglo-American discourses of politics, gender, and religion in the region. In negotiation with Edward Said's Orientalism, I develop a materialist postcolonial critical model to analyse how such discourses undergird publishing and marketing strategies towards novels by Ibrahim Nasrallah, Hisham Matar, Yasmin Crowther, Orhan Pamuk, and others. I argue that as Middle Eastern novels travel, whether via translation or authorial acts of migration, across cultures and languages, they are reshaped according to dominant audience expectations. But, I continue, they also retain traces of their source cultures which must be brought to the surface in critical readings. Drawing on the work of David Damrosch, Pascale Casanova, Franco Moretti, and Aamir Mufti, I thus develop a reading practice, what I call 'post-Orientalist comparatism', that allows me to read past the domesticating strategies framing these novels and to newly reveal their more local, thus potentially transgressive, takes on Middle Eastern socio-political issues. I cumulatively suggest that Middle Eastern novels in English formally embody a dialectic of 'East' and 'West', of the local and the global, thus have important implications for our understanding of the English and world novel traditions.
I conceive of my thesis as a dual intervention into the fields of postcolonial studies and world literature. I am primarily concerned to reorient postcolonial theory around questions of Middle Eastern literary and cultural production, areas that have been traditionally neglected due to an entrenched, but unsustainable, anglophone bias. To do so, I turn to the work of Edward Said, and rethink the foundational problematic of Orientalism with an eye towards political, material, and cultural developments since 1978, the year in which Orientalism was first published, and towards the unique transnational positionality of the genre of the Middle Eastern novel in English. I also turn to theorists of world literature such as David Damrosch in order to develop a reading practice thoroughly attentive to issues of circulation, but, along the lines set out by Aamir Mufti, seek to interrogate their work for its occlusions of the impact of orientalist discourse in the historical development of the category of 'World Literature'. My thesis thus not only draws on postcolonial and world literary theory to analyse its object, the Middle Eastern novel in English, but also demonstrates how proper attention to this object necessitates a theoretical recalibration of these fields.
The dynamics of innovation contests using firm-hosted communities
Keywords: online community
innovation contests
crowdsourcing

Firms pursuing an open innovation strategy have increasingly turned to individuals as sources of new ideas. Two main approaches are often highlighted. First, firms can use online innovation contests, where individuals submit ideas in competition for a prize. Second, firms can use firm-hosted online communities, drawing from collaborative efforts of individuals with more intrinsic motivations to participate. A central challenge in both cases is that firms often struggle to sustain participation and effort of participants on an on-going basis. A third hybrid approach, where firms establish community-based innovation contests, has been largely ignored by research, but seems to help firms to engage participants on an on-going basis. This study focuses on community-based innovation contests to understand how firms engage communities to participate in contest over time. I conducted fieldwork at two firms that have successfully run them for many years, Chicago-based T-Shirt firm Threadless and Phoenix-based automotive firm Local Motors. Over ninety interviews with firm employees and community members, over six months of on-site observation at the two firms’ headquarters as well as internal documents and blog data have been collected and analysed. Based on this data the core of the thesis consists of three empirical chapters that examine how firms are able to engage the communities to participate in their contests on a regular basis. First, it shows that the addition of a community to contests increases contestants’ opportunities to learn. In experiential learning, contests provide experience whereas the community provides room for reflection and learning. These learning opportunities motivate contestants to come back and create contest entries on an on-going basis. Secondly, taking a social identity perspective, the research shows how the firms are able to engage the community members continuously by creating a joint firm-community identity. Lastly, it explains how these firms are able to influence community members’ perception of the tasks they are doing through the contest design. Firms are able to turn activities that have been traditionally regarded as work into a recreational activity.
Worker responses to work reorganisation in a deep-level gold mining workplace: perspectives from the rock-face
Keywords: workers
consent
agency
control
resistance
sociology
management

In the early 1990s, South Africa’s re-entry into the competitive global marketplace and the first non-racial elections brought significant changes to an industry previously plagued by the racialisation of the labour process. South Africa’s post-apartheid work order led to the restructuring of the gold mining workplace, with a greatly increased emphasis on efficiency, productivity and equity. This period saw a number of gold mines reorganising work through new forms of working practices aimed at creating new kinds of workers who could identify with the goals of the company by expending rather than withdrawing effort at the point of production. There was a shift in the attitude of worker responses to managerial practices, from coercion to consent in the day-to-day running of the production process.
This thesis examines worker responses to the reorganisation of work and their impact on worker and workplace productivity in a deep-level gold mine. At the core of this thesis are the perceptions, views, experiences and reactions displayed by underground work teams to management initiatives. The thesis highlights the significance of worker agency in managerially defined work structures – the capacity of underground gold miners to reshape and adapt management strategies in ways that make sense and enable them to maintain control over production and the effort-bargain.
The findings presented in this thesis, particularly the gold miners’ informal or coping strategy of making a plan (planisa), reveal that underground work teams are not merely passive or docile reactors to management initiatives. They find opportunity to manipulate (and where necessary, avoid) new forms of management control in a variety of innovative ways that enable them to reassert their power and autonomy over their working day. Underground gold miners are not simply appendages to nor alienated beings in the production process but are able to take control of the production process, independent of management prescriptions, in ways which may embody resistance, consent or a subtle combination of the two. The thesis calls attention to workers’ subjective orientation, agency and resilience to new work structures – not just as recipients but also as shapers of such new work structures within the politics, limits and contradictions of capitalist production systems.
Recalibrating ancient mythology for contemporary performance: the Mises en scène of the Mahabharata by Peter Brook and Les Atrides by Ariane Mnouchkine
Keywords: mythology
French theatre
directing
culture

There is consensus in academic circles that the directors Peter Brook and Ariane Mnouchkine have similar approaches to theatre practice and occupy the same position in the landscape of theatre production in France. Yet there have not been any in-depth studies that unpack the similarities and differences between the two practitioners. Considering their stature on the national French and international stages, such a gap of scholarship needed to be filled. By examining the specificities of their practices via the analysis of their two most emblematic productions, the Mahabharata and Les Atrides, this thesis hopes to provide an appraisal of their practices at a time when they are moving away from theatre. More specifically, this thesis looks at how the two directors transferred ancient archetypal and mythological narratives to the contemporary French stage. It considers how they used successful, parallel methodologies to adapt and render present an Ancient Sanskrit epic on the one hand (Brook), and Ancient Greek drama on the other (Mnouchkine). I uncover in their work the matrix for adaptation, located in the discourse of storytelling and in the post-Brechtian concept of estrangement, that I label ‘décalage’. Moreover, the thesis hopes to provide an appraisal of the supremacy of directors on the French stage in the nineteen eighties and advocates for the cultural necessity of theatre as an art form, at a time of crisis in France.
What makes dual career couples successful?
Keywords: Family Sociology
Dual Careers
Longitudinal
Panel

I use the German Socio-Economic Panel to explore three dimensions of couples' career success: career input (hours), career output (wages) and happiness. I focus on West German parents because, until recently, they faced low levels of state-level childcare support and adverse attitudes towards maternal employment.
I investigate the extent to which couples specialize in paid work in the long term. Previous approaches – even those using couple-level longitudinal data – failed to explore this fully, instead examining men and women separately, or a single transition. I develop a “dual curve” approach and find that even among the 1956-65 female birth cohort (which faced low state-level support for dual employment) only a fifth of all couples adopt full specialization in later life. A sizable proportion – a third – moves into dual fulltime employment, while half of highly educated couples adopt such employment. Highly educated women are not only less likely to permanently specialize but also more likely to try working full-time, possibly because their partners' comparative advantages are lower.
I explore whether the take-up of work hour flexibility relates to rises in both the respondent’s and their partner’s wages. Men and women benefit from working flexibly, even when controlling for selection into work hour flexibility with growth-curve and fixed effects analysis. Moreover, there is a positive cross-partner wage effect, which is particularly pronounced for mothers, suggesting that men – the main users of the policy – use this measure to support their wives' careers.
Are dual career couples (equal human capital investment) happier than specializing couples? I create a human capital measure to account for differential human capital during periods of non-employment, which has been ignored in past analyses. I find that women in dual career couples are unhappier when the child is young but happier later in life. Conversely, women who give precedence to their partner’s career in terms of human capital investment grow unhappier.
Multilocus sequence analysis of the pathogen Neisseria meningitidis
Keywords: evolution
pathogen
Neisseria meningitidis
meningitis
genetics

Neisseria meningitidis is the bacterium responsible for meningococcal meningitis and septicaemia in humans. Meningococcal disease is primarily a disease of young children, characterized by rapid deterioration from first symptoms to death, with an 11% fatality rate and a global distribution. Patterns of genetic diversity in meningococcal populations provide an account of their evolutionary history and structure, which can be inferred by population genetics modelling. Understanding these phenomena can inform control and prevention strategies, and provides interesting case studies in evolution. The aim of this thesis is to develop population genetics techniques for inferring the evolutionary history of meningococci.
I begin by reviewing the field, and justifying the use of coalescent methods in modelling microparasite populations. Inference on carriage populations of meningococci under the standard neutral model and the neutral microepidemic model is performed using a modification to approximate Bayesian computation. AMOVA and Mantel tests are used to quantify the differentiation between carriage and disease populations, and the extent to which geography and host age structure carriage populations. The results are used to propose revised coalescent models for meningococcal evolution.
The role of natural selection in shaping meningococcal diversity is investigated using a novel method that utilises an approximation to the coalescent and reversible-jump Markov chain Monte Carlo to detect sites under selection in the presence of recombination. Having performed a simulation study to assess the statistical properties of the method, I apply it to the porB antigen locus and seven housekeeping loci in N. meningitidis. There is strong evidence for selection imposed by the host immune system in the antigen locus, but not the housekeeping loci which are functionally constrained. Finally I discuss the future direction of population genetic approaches to understanding infectious disease.
A lipid fusion based method for the single molecule study of ATP synthase
Keywords: Protein
Nanotechnology
ATP
Synthase
Darkfield
Lipid

ATP synthase is a ubiquitous transmembrane protein that utilises the free energy available from ion gradients across lipid membranes to synthesise adenosine triphosphate (ATP). It may be separated into two parts - the membrane-embedded (i.e. hydrophobic) FO and the hydrophilic F1. Each undergoes a rotary motion. Single-molecule studies on the rotation of the isolated hydrophilic F1 have been performed for many years; attempts to construct an experiment in which to view the rotation of the membrane-embedded F1FO complex under high space- and time- resolution (such as by attachment of a rotational probe) have not yet seen a satisfactory method emerge in the literature. Most particularly, a clear ability to generate and control a proton-motive force across the membrane in which the F1FO is sited is needed to probe ATP synthesis.
This thesis presents the development of a candidate method for such single-molecule studies.
By the use of a water-in-oil emulsion, giant unilamellar lipid vesicles are formed which entrap arbitrary components - including functionalised gold nanospheres of 60-100 nm diameter, which move freely in the internal space. A charge-based lipid fusion is developed, using mixtures of natural lipid extracts with anionic and cationic lipids. It is demonstrated that anionic giant vesicles fuse with cationic small vesicles with full content mixing and transfer of bilayer leaflets. It is shown that F1FO is functional in the cationic lipid mixture. Methods are shown to bind such a cationic proteoliposome to a surface and for it to fuse with an anionic giant vesicle containing functionalised gold nanospheres. Backscatter laser darkfield is used to search for rotation of the gold nanospheres under ATP hydrolysis conditions of the F1FO; unidirectional rotation is seen in one instance and other suggestive traces are shown with speculative analysis. Further work is proposed.
Silicon nanocrystals embedded in silicon carbide for tandem solar cell applications
Keywords: Silicon Nanocrystal
Electrical transport
Silicon Carbide
Solar Cell
Luminescence
Diffusion

Tandem solar cells are potentially much more efficient than the silicon solar cells that currently dominate the market but require materials with different bandgaps. This thesis presents work on silicon nanocrystals (Si-NC) embedded in silicon carbide (SiC), which are expected to have a higher bandgap than bulk Si due to quantum confinement, with a view to using them in the top cell of a tandem cell.
The strong photoluminescence (PL) of precursor films used to prepare Si-NC in SiC (Si-NC/SiC) was markedly reduced upon Si-NC formation due to simultaneous out-diffusion of hydrogen that passivated dangling bonds. This cannot be reversed by hydrogenation and leads to weak PL that is due to, and limited by, non-paramagnetic defects, with an estimated quantum yield of ≤5×10-7. Optical interference was identified as a substantial artefact and a method proposed to account for this.
Majority carrier transport was found to be Ohmic at all temperatures for a wide range of samples. Hydrogenation decreases dangling bond density and increases conductivity up to 1000 times. The temperature-dependence of conductivity is best described by a combination of extended-state and variable-range hopping transport where the former takes place in the Si nanoclusters. Furthermore, n-type background doping by nitrogen and/or oxygen was identified.
In the course of developing processing steps for Si-NC-based tandem cells, a capping layer was developed to prevent oxidation of Si-NC/SiC, and diffusion of boron and phosphorus in nanocrystalline SiC was found to occur via grain boundaries with an activation energy of 5.3±0.4 eV and 4.4±0.7 eV, respectively. Tandem cells with a Si-NC/SiC top cell and bulk Si bottom cell were prepared that exhibited open-circuit voltages Voc of 900 mV and short-circuit current densities of 0.85 mAcm-2. Performance was limited by photocurrent collection in the top cell; however, the Voc obtained demonstrates tandem cell functionality.