VictorJuiz/thesis huggingface dataset:
Return of high skilled migrants: an empirical investigation into the knowledge transfer process of two organizations in New Delhi, India
Keywords: Economic Development
Return Migration
Knowledge Transfers

Against the backdrop of the brain drain-brain gain debate, this thesis explores certain facets of the return migration phenomenon. Drawing on several theories, the decision to return among high skilled migrants is likely to be influenced by the prospect of using their overseas-acquired knowledge to secure a better livelihood back home. While ample consideration is given to motivations to return, the choice of employer and issues adjusting to the work and social surroundings, the main objective of the research is to understand migrants' transfer of overseas-acquired knowledge upon their return to India.
Given the interdisciplinary nature of the topic, the scope of the thesis is focused on returnees working in two organizations in New Delhi—Fortis Escorts Hospital and Research Centre (EHIRC) and Tata Consultancy Services' Government Industry Solutions Unit (GISU). Adopting a mixed methods approach, survey data and case interviews are analyzed to address the core research question: “How and in which ways do returnees transfer their newly acquired knowledge, skills and experiences in employing organizations?” A key hypothesis is that returnees' social ties affect the extent and nature of knowledge transfers and thus confer intended benefits and may lead to unintended consequences for their organizations.
The analyses pit McPherson's (2001) principle of homophily in social networks against Granovetter's (1973) weak ties hypothesis to grasp the role of returnees in knowledge transfers within EHIRC and GISU. Results drawn from data collected on returnees, non-migrants and transnationals strongly confirm that social ties—strong, intermediate or weak—affect the transfer of knowledge to stakeholders in their organizations. The contribution of this thesis to the existing body of research is to shed light on both the potential and limitations of returnees as a conduit for transferring knowledge, upgrading skills and relaying insights to non-migrants, teams or units in the workplace.
Life after guns: the life chances and trajectories of ex-combatant and other post-war youth in Monrovia, Liberia
Keywords: Ex-combatants
Liberia
Youth
Post-war

This thesis is about the life chances and trajectories of ex-combatant and other youth in post-war Monrovia, Liberia. In it I present the results of a qualitative inquiry into the relationship between shifting structural conditions and youth agency in the aftermath of 14 years of civil war. Much of the literature concerned with ex-combatant “reintegration” remains a-theoretical and fails to situate their experience within the contours of transition from structures in armed groups to structures in post-war society. It is rife with normative assumptions about how ex-combatants should “return” to civilian life. The ex-combatant trajectories detailed in this study challenge this literature reflecting neither “reintegration” nor “return.” Instead, they highlight how ex-combatants negotiate a complex environment in which structural norms, values, and relationships converge and conflict after war. To demonstrate this, the thesis presents an analysis of the relationships between structural constraints and youth agency among youth who fought, and others who did not. In so doing, it provides a situated analysis of post-war society which is often missing in the literature concerned with ex-combatants. The empirical material shows the significance of interdependent relationships at the level of the family and the household. It is “wealth in people” at this proximate level that supports survival and enables socio-economic mobility, with implications for social respect. Without patronage through family and kin, socio-economic possibilities diminish significantly. This means that options available to many ex-combatants are limited after war, as they are often unable or unwilling to be incorporated into families and former communities. Their navigation of the post-war social terrain reflects efforts to survive and maintain respect through patrimonial relationships within and outside of their structured networks from war. Some retain the status and respect they achieved in war through relationships maintained from their years of conflict. Others were able to survive and achieve respect through new or renewed relationships with families and extended kin. Life chances and trajectories emerge from embedded positions within structured social relations that are produced and reproduced in the aftermath of conflict. With this work, I argue that social processes are vital to any theorisation about life after war.
Computer simulation of the homogeneous nucleation of ice
Keywords: ice
homogeneous nucleation
rare event
Monte Carlo
simulation
water

In this work, we wish to determine the free energy landscape and the nucleation rate associated with the process of homogeneous ice nucleation. To do this, we simulate the homogeneous nucleation of ice with the mW monatomic model of water and with all-atom models of water using primarily the umbrella sampling rare event method. We find that the use of the mW model of water, which has simpler dynamics compared to all-atom models of water, but is nevertheless surprisingly good at reproducing experimental data, results in very reasonable agreement with classical nucleation theory, in contrast to some previous simulations of homogeneous ice nucleation. We suggest that previous simulations did not observe the lowest free energy pathway in order parameter space because of their use of global order parameters, leading to a deviation from classical nucleation theory predictions.
Whilst monatomic water can nucleate reasonably quickly, all-atom models of water are considerably more difficult to simulate, primarily because of their slow dynamics of ice growth and the fact that standard order parameters do not work well in driving nucleation when such models are being used. In this thesis, we describe a local, rotationally invariant order parameter that is capable of growing ice homogeneously in a biassed simulation without the unnatural effects introduced by global order parameters, and without leading to non-physical chain-like growth of 'ice' clusters that results from a naïve implementation of the standard Steinhardt-Ten Wolde order parameter. We have successfully used this order parameter to force the growth of ice clusters in simulations of all-atom models of water.
However, although ice growth can be achieved, equilibrating simulations with all-atom models of water is extremely difficult. We describe several approaches to speeding up the equilibration in all-atom models of water to enable the computation of free energy profiles for homogeneous ice nucleation.
Methods, rules and limits of successful self-assembly
Keywords: simulations
Monte Carlo
proteins
Colloids
self-assembly

The self-assembly of structured particles into monodisperse clusters is a challenge on the nano-, micro- and even macro-scale. While biological systems are able to self-assemble with comparative ease, many aspects of this self-assembly are not fully understood. In this thesis, we look at the strategies and rules that can be applied to encourage the formation of monodisperse clusters. Though much of the inspiration is biological in nature, the simulations use a simple minimal patchy particle model and are thus applicable to a wide range of systems. The topics that this thesis addresses include: Encapsulation: We show how clusters can be used to encapsulate objects and demonstrate that such `templates' can be used to control the assembly mechanisms and enhance the formation of more complex objects. Hierarchical self-assembly: We investigate the use of hierarchical mechanisms in enhancing the formation of clusters. We find that, while we are able to extend the ranges where we see successful assembly by using a hierarchical assembly pathway, it does not straightforwardly provide a route to enhance the complexity of structures that can be formed. Pore formation: We use our simple model to investigate a particular biological example, namely the self-assembly and formation of heptameric alpha-haemolysin pores, and show that pore insertion is key to rationalising experimental results on this system. Phase re-entrance: We look at the computation of equilibrium phase diagrams for self-assembling systems, particularly focusing on the possible presence of an unusual liquid-vapour phase re-entrance that has been suggested by dynamical simulations, using a variety of techniques.
Art after Auschwitz. Dimensions of ethics and agency in responses to genocide in post World War II art practice
Keywords: visual cultures
art
genocide scholarship
cultural studies
Adorno
memory
art and resistance
critical theory
art practice
art history
genocide
genocide studies
art and complicity

Rather than being located in a field of art that addresses genocide through assumptions connected with identity issues or activism, this thesis of an artist’s exploration of artistic response to genocide in post World War II art practice, is informed by the emerging field of genocide scholarship. Seeing a parallelism between the concerns of genocide scholars and artists who respond to genocide, this thesis is an interdisciplinary study of art positioned alongside the field of genocide scholarship, as theorised by scholars such as Donald Bloxham and A. Dirk Moses. In addressing genocide through broader historical trends, periods and structures, it assumes that artists who respond to genocide share with genocide scholars a concern about genocide at a secondary level and share the potential to create illumination in the field. This thesis explores art practices that address genocide conceptually through structure and material. The central claim of this thesis is that recent and contemporary art practices, here discussed, show a concern to respond to genocide as an ethical response, and that they do so by engaging with the complexity of abstract issues such as complicity and agency. The initial analysis of Adorno’s discourse on ethics, as it relates to response in art, sets up a level of complexity for two further investigations that interrogate the discourses of victim representation and lens-based documents of genocide through ethics and agency. Together these provide an analytical framework for the project. Close readings informed by genocide scholarship, of art practices including those of Jimmie Durham and Francis Alÿs, take forward notions in the existing critical field. These readings yield not only the evidence that demonstrates a commitment to creating ethically based art through conceptually informed practice, in artists responding to genocide, but also the value of a cultural critique that is informed by genocide scholarship.
Inscribed within the image: the visual character of early Christian mosaic inscriptions
Keywords: epigraphy
inscriptions
Latin
Greek
mosaics
Late antique art

Between the fourth and the seventh centuries CE, Christian patrons erected thousands of churches, chapels, and monasteries in cities and villages across the Mediterranean, decorating the apses, walls and floors of many of these structures with figural and geometric mosaics. These late antique Christian mosaics have been studied for their iconography, their Graeco-Roman components, and as evidence for the religious beliefs of newly-Christian patrons. However, art historians largely have ignored the ways that texts, inscribed within the visual field and composed of the same mosaic material, functioned as images in Christian spaces. For the first time, this thesis assembles the foundations of a comprehensive catalogue of early Christian mosaic inscriptions, places them back into the physical spaces in which they were meant to be read, and analyzes how these texts functioned both verbally and visually for the late antique reader/viewer, against the backdrop of Graeco-Roman traditions. I first examine the ekphrastic components of Christian inscriptions and look more closely at the different ways in which texts work with and against images and spaces, encouraging the viewer to react physically and mentally. Second, I study the language of light used by the inscriptions, and argue that this language linked text to the material of mosaic and enabled patrons to make complex statements about their cultural erudition and religious affiliation. Third, I investigate the functions and visual forms of short tituli which label scenes or name figures to simplify, authenticate or transform static images into narratives in motion. Finally, I turn to the frames of the inscriptions and contend that different forms conveyed powerful visual arguments. By writing these texts back into their mosaics, this thesis argues that texts and images were inseparable in the period, and that text written into images performed and played in more complex ways than has been previously thought.
Local elites and local coinage: elite self-representation on the provincial coinage of Asia 31 BC- AD 275
Keywords: Roman Provincial Elites
Roman Asia Minor
Ancient Numismatics

The focus of this thesis is the nature of the interaction between the civic elites and the civic coinage for which they were responsible. The Roman Province of Asia provides the ideal context for the study of local elites and their coinage because of the prevalence and prominence of the names of individual local notables, henceforth known as eponyms, recorded in civic coin legends. By combining the study of the function of coin eponyms and the prosopographical analysis of individual eponyms in the epigraphic record, it is possible to identify and explain the profound changes that affected civic coin production in the first three centuries AD. Local elites perceived coinage not only in terms of a functional means of exchange, but as a medium for personal and civic display. In this way the local elites exploited coin iconography in ways that paralleled other media of monumental display. New coin legends were developed, which identified explicitly the dedicatory nature of the coinage and the iconographic repertoire of coin types was radically expanded to express the cultural agendas and priorities of the civic elites.
The first half of the thesis is devoted to the study of the relationship between office holding and coinage and the development of coin legend formulae during the first three centuries AD. The pattern and distribution of the various legend formulae is analysed in order to determine the extent of the eponym’s involvement in the production of coinage. In particular, this section intends to establish the extent to which coinage production was funded privately. The fourth chapter is arranged into a series of case studies discussing individual cases of personalized coin iconography. The final chapter of the thesis outlines how the civic elite’s conceptualization of coinage changed over the course of this period. It is argued that contact with the Roman monetary tradition affected civic elites’ attitude to coinage and that this manifested itself in the iconography and the fabric of the coins themselves.
Visible light commuinications using optical OFDM
Keywords: MIMO
OFDM
VLC

This thesis presents an investigation into designs and developments of indoor visible light communication (VLC) systems using orthogonal frequency division multiplexing (OFDM) schemes. The novel contribution of this thesis is a development of a visible light communication system that incorporates OFDM and imaging-diversity multiple-input multiple-output (MIMO) techniques, which allows robust transmissions on multiple channels at high data rates.
The characteristics of VLC systems are presented, one of which is VLC communications channel exhibits high Signal-to-Noise Ratio (SNR). The major constraint however, is the low modulation bandwidth of typical high power white LED sources.
The performance of OFDM as a modulation scheme is investigated. OFDM offers the possibility for bit and power loading to increase bandwidth efficiency, as well as a straightforward equalisation in time and frequency domains to compensate the low pass frequency response of the LED. This allows transmission rates of up to ~310Mbps at a BER of 2x10-3 on a single-channel link using 16- QAM DCO-OFDM. Further increase in data rates for this transmission is constrained by the available signal power due to a dynamic range limitation at the receiver. An increase in signal power will results in the OFDM waveform to be clipped, which incurs a clipping noise.
MIMO systems offer a linear capacity gain to a number of transmission channels in an ideal configuration. These systems mitigate the dynamic range limitation, as power is divided between multiple channels. The performance of a MIMO transmission system is investigated under the same dynamic range constraint. A 4-channel MIMO transmitter is built using four sets of transmitter components of the single-channel link. An imaging system is used to separate the received optical power onto multiple detectors, and MIMO processing relaxes the requirements for precise mechanical alignments. The experiment has shown that the imaging MIMO system further improves data rates and transmissions of up to ~1.1Gigabit/s at a BER of 2x10-3 are achieved. To the best of the author’s knowledge, this is the highest reported for an indoor VLC MIMO-OFDM transmission. Also presented is an analysis of MIMO system scalability to provide room-wide coverage.
Finally, this thesis presents an extended analysis of several other optical OFDM approaches, and concludes with recommendations of future work to increase the data rates of indoor VLC systems.
A causal perspective on random geometry
Keywords: hep-th

In this thesis we investigate the importance of causality in non-perturbative approaches to quantum gravity. Firstly, causal sets are introduced as a simple kinematical model for causal geometry. It is shown how causal sets could account for the microscopic origin of the Bekenstein entropy bound. Holography and finite entropy emerge naturally from the interplay between causality and discreteness. Going beyond causal set kinematics is problematic however. It is a hard problem to find the right amplitude to attach to each causal set that one needs to define the non-perturbative quantum dynamics of gravity. One approach which is ideally suited to define the non-perturbative gravitational path integral is dynamical triangulation. Without causality this method leads to unappealing features of the quantum geometry though. It is shown how causality is instrumental in regulating this pathological behavior. In two dimensions this approach of causal dynamical triangulations has been analytically solved by transfer matrix methods. In this thesis considerable progress has been made in the development of more powerful techniques for this approach. The formulation through matrix models and a string field theory allow us to study interesting generalizations. Particularly, it has become possible to define the topological expansion. A surprising twist of the new matrix model is that it partially disentangles the large-N and continuum limit. This makes our causal model much closer in spirit to the original idea by 't Hooft than the conventional matrix models of non-critical string theory.
Asymmetric conjugate addition reactions
Keywords: organic chemistry
asymmetric synthesis
conjugate addition
chemical methodology

This thesis is concerned with the asymmetric conjugate addition reactions of a range of chiral nucloeophiles.
Chapter 1 introduces the conjugate addition reaction as a valuable carbon-carbon and carbon-heteroatom bond forming reaction in organic chemistry, and explores the asymmet- ric conjugate addition of a range of chiral and achiral carbon and nitrogen nucleophiles to a range of acceptors.
Chapter 2 explores the use of the N-benzyl-N-(α-methylbenzyl)amino group as a chi- ral auxiliary, by employing the attempted conjugate additions of both N-benzyl-N-(α- methylbenzyl)hydrazine and N -benzyl-N -(α-methylbenzyl)hydroxylamine as chiral ammo- nia and water equivalents respectively.
Chapter 3 describes the asymmetric and stereoselective preparation of a range of 4,4- disubstituted isoxazolidin-5-ones from the conjugate addition of lithium (S)-N-tert-butyl- dimethylsilyloxy-N -(α-methylbenzyl)amide. The isoxazolidin-5-ones are then globally de- protected via hydrogenolysis, giving rise to the corresponding β2,2,3-amino acids.
Chapter 4 focuses on the development of a protocol to effect the conjugate addition of a chiral aniline equivalent. The scope of the reaction is delineated by varying both the nu- cleophile and the α,β-unsaturated ester. Finally, cyclisation of the β-N-arylamino esters to the corresponding tetrahydroquinolines is explored, and an application to the synthesis of the natural product (−)-angustureine is presented.
Chapter 5 contains full experimental procedures and characterisation data for all com- pounds synthesised in Chapters 2, 3 and 4.
Principles of hydrogen catalysis in the presence of oxygen by a [NiFe] hydrogenase from E. coli
Keywords: mass spectrometry
reactive oxygen species
hydrogen
nickel-iron hydrogenase
oxygen isotopes
oxygen tolerance
oxidase

[NiFe] hydrogenases are metalloenzymes that act as highly efficient molecular electrocatalysts for the interconversion of protons and molecular hydrogen. Unlike any other known molecular electrocatalyst, the members of a subgroup of respiratory membrane-bound [NiFe] hydrogenases are able to maintain H2 catalysis in the sustained presence of O2. This O2-tolerance depends on the ability to respond to oxidative inactivation by O2 by exclusively forming rapidly reactivated active site states, thus implying a catalytic cycle in which O2 acts as a competing substrate to H2.
Using isotope ratio mass spectrometry it is proven that the O2-tolerant Escherichia coli Hydrogenase 1 responds to O2 attack by acting as a four-electron oxidoreductase, catalysing the reaction 2 H2 + O2 → 2 H2O, equivalent to hydrogen combustion. Special features of the enzyme’s electron relay system enable delivery of the required electrons. A small fraction of the H2O produced arises from side reactions proceeding via reactive oxygen species, an unavoidable consequence of the presence of low-potential relay centres that release electrons from H2 oxidation. While the ability to fully reduce O2 to harmless H2O at the active site to generate the rapidly reactivated state Ni-B, determines if a hydrogenase is O2-tolerant, the ratio of oxidative inactivation to reductive reactivation rates determines how tolerant the enzyme is.
It is shown by protein film electrochemistry that the (αβ)2 dimeric assembly of Hyd-1 plays an important role in O2-tolerance by aiding reactivation of one catalytic unit through electron transfer from the other. The teamwork between two redundant partners implicates a new role for dimerisation and represents a new example of cooperativity in biology.
Finally, the non-natural amino acid p-azido-L-phenylalanine was synthesised and incorporated into Hyd-1, testing the possibility of introducing labels at specific sites.