VictorJuiz/thesis huggingface dataset:
Velocity and attenuation structure of the mantle: constraints from differential properties of shear waves

Although much progress has been made in determining the three dimensional distribution of seismic wave velocities in the Earth, substantially less is known about the three dimensional distribution of intrinsic attenuation. In this study variations in attenuation and shear velocity of the Earth's mantle are constrained using measurements of differential travel time and attenuation.
The data are broadband displacement SH seismograms filtered to have energy in the period range 8 to 20 s. Broadband data are used as they should allow a more accurate estimation of body wave attenuation to be made. The seismograms are obtained from over 600 globally distributed earthquakes of magnitude, Mw, 5.5 or greater.
Two new methods for determining differential travel times and differential t* values from multiple S phases are presented. The first of these, referred to as the "waveform fitting method" is used to analyse approximately 4300 SS and S waveforms and around 1000 SSS and SS waveforms resulting in differential SS-S and SSS-SS travel times, and corresponding values of differential attenuation represented by t*. The second method, referred to as the "spectral ratio method" is used to analyse approximately 3200 SS and S and around 900 SSS and SS waveforms.
The differential travel times and t* values are inverted to obtain models of the lateral variation of shear velocity and lateral variation of q(mu) where q(mu) =1/Q(mu). The models explain the data well but have limited depth resolution. The velocity models show good correlation with previous studies, in particular, low velocities are observed underlying spreading ridges and convergent margins and high velocities are observed under continental regions. The q(mu) model shows shield regions to be less attenuating than PREM, with ridges appearing as highly attenuating features.
Models of shear velocity and attenuation are also obtained by combining the body wave dataset of this study with the surface wave datasets of Van Heijst (1997) and Selby (1998).

Keywords: upper mantle
S-waves
attenuation
Advisor: Woodhouse, J
The art of Chinese management?

An empirical study was undertaken (a) to examine the characteristics, influencing factors, and effectiveness of a distinctive Chinese management model adopted by the newly founded private enterprises in mainland China, as well as (b) to test the "fit" notion in contingency theory. The study was based on a random sample of 124 standardized personal interviews with CEOs of Chinese industrial and service companies in Beijing and Shanghai. The standardized questionnaire mainly contained the Aston structure scales (Pugh and Hickson 1976) and Khandwalla's (1977) management schedules. Besides, three case examples were studied including one state-owned bank and two private enterprises. Using AMOS structural equation modeling, size, masstechnology and uncertainty, as well as CEO need for achievement, environmental constraints and selected Chinese characteristics, were specified as influencing factors of "bureaucracy" and managerial practices, which included strategic orientation, leadership style, decision-making, communication and subcontracting. Another model analyzed the influence of various key success factors on organizational effectiveness.
The findings provided support for the re-adoption of a distinctive Chinese management model in private companies, characterized by autocratic leadership, low formalization, "Chinese entrepreneurship" and network-based "webs". Private enterprises also tended to readopt and emphasize traditional Chinese family-related values. The distinctiveness of this model was, ceteris paribus, due to this emphasis on familism, which had a direct impact on organizational design and an indirect influence through its negative association with company size, which in turn significantly covaried with organizational design. This family-based ownership model was positively associated with organizational effectiveness. As regards contingency theory, the "traditional" fit hypotheses could not be rejected. In addition, less effective companies were not necessarily in "misfit". "Appropriate" structure, together with an optimizing planning style and firm age, were positively associated with performance. Managerial recommendations were codified in a CHINA strategy framework for high effectiveness.
Finite differences for the convection-diffusion equation

The solution of convection-diffusion problems is a challenging task for numerical methods because of the nature of the governing equation, which includes a non-dissipative component and a dissipative component. Once the convection-diffusion equation is discretised, it is usual to observe oscillations in the computed solution regardless of whether these might be expected in the original physical situation. Mostly these oscillations are the result of numerical instability. This thesis centres on this fundamental difficulty: the numerical stability of finite difference discretisation of a convection-diffusion equation.
The existence of an exact evolution operator for the constant coefficient convection diffusion problem is the framework we use to derive new finite difference schemes in one and two dimensions and also, when a high-order scheme is considered, to derive numerical boundary conditions. The influence of numerical boundary conditions on the stability of a general scheme is one of the main themes. The stability analysis is done mostly by using the von Neumann method and the matrix method. The Godunov-Ryabenkii theory is also applied to the one dimensional case.
In two dimensions we deduce different forms of second-order (Lax-Wendroff) schemes and third-order (Quickest) schemes. We apply some of those schemes to a Navier-Stokes problem by running experiments to illustrate the practical stability region, showing how results from a simpler case presented in previous chapters carry over to the more complex case.

Advisor: Sobey, I
The theological vision of Reinhold Niebuhr's "The irony of American history"

Reinhold Niebuhr remains at the center of a national conversation about America's role in the world, and commentators with divergent political and religious positions look to his 1952 work, The Irony of American History, in support of their views. In this study, Scott R. Erwin argues that an appreciation of Niebuhr's theological vision is necessary for understanding the full measure of Irony and his perspective on life more broadly. Such a study is important because many individuals reading Irony today fail to acknowledge the central role that his Christian beliefs played in his writings. Niebuhr described his theological vision as being 'in the battle and above it,' and, it was this perspective that led Niebuhr, in Irony, to assert that America must both take 'morally hazardous action' in combating the aggression of the Soviet Union and engage in critical self-evaluation to prevent the country from assuming the most odious traits of its Cold War foe.
Niebuhr developed his theological vision over the course of the 1930s and 1940s through engagement with Christian doctrine, as most readily seen in his academic works such as The Nature and Destiny of Man, and engagement with current events, as seen in his many journalistic writings during this period. By focusing primarily on Niebuhr's writings between 1931 and 1951, Erwin traces the development of his Christian interpretation of human nature and history, establishes how it informed his theological vision, and reveals how that theological vision underlay his writings on current affairs.

Keywords: Reinhold Niebuhr
American Foreign Policy
Theology and Politics
Advisor: Rasmussen, J
Land, distributive politics and rural governance in reform China

This thesis is concerned with distributive politics arising from land development and territorial changes in reform China. It adopts a historical institutionalist approach in examining the evolution of rural institutions, with a specific focus on the rural shareholding cooperative and the village joint stock company. It argues that despite the move towards the market in the reform era, core elements of the state socialist redistributive economy imposed upon rural society in the Maoist era have been sustained and reproduced in the two reform-era institutions. The re-collectivisation of the village through the shareholding reform has provided the institutional foundations for the continued deployment of redistributive power and the reproduction of paternalistic relations that generate expectations of the fulfilment of an implicit social contract.
This thesis argues that while the reforms have helped to hold the village together in the midst of drastic territorial change, the very operation of the institutions may be generating endogenous pressures for change as they heighten propensity of power abuse and produce unequal distributive outcomes. These internal contradictions were exacerbated by the checun gaizhi reform, which abolished grassroots organisations of self-governance and created semi-private entities, which by their straddled nature were not subjected to any effective mechanisms of checks and balances. This privatisation of rural governance has profound implications on rural outcomes. By comparing and contrasting the divergent trajectories undertaken by three villages that shared similar characteristics, this thesis sheds light on some of the deeply problematic aspects of rural governance in contemporary China.

Keywords: China
urbanization
politics and government
land use
rural development
Advisor: Thornton, P
New techniques in nuclear magnetic resonance

The effect of short, strong radiofrequency pulses on the nuclear spin system is examined. Providing the durations of the pulses are short with respect to coupling constants within the spin system, they may be described by simple rotation operators which are exponential functions of the angular momentum operators. Operator algebra can be used to define the interaction of such pulses with the spin system, and the mutual interaction of a sequence of pulses. The case of a simple coupled spin system is examined in detail and it is found that a vector model can be used to describe the motion of the expectation values of the observables. This model also allows treatment of such 'non-classical 1 effects as coherence transfer and multiple-quantum coherence. The proposal is also made that certain types of pulse imperfection may be compensated by using specially constructed sequences of small numbers of pulses, which are termed 'composite pulses'. Their compensatory action is illustrated by computer simulation, and by experimental results. In the case of certain symmetrical composite pulses, operator algebra can be used to understand their overall effect in the presence of pulse imperfections, suggesting their use in such critical applications as multiple spin echo trains. Another class of symmetrical composite pulses provides rotations by arbitrary angles around the z-axis of the rotating reference frame, and is expected to be of use in multiple-quantum spectroscopy.

Advisor: Freeman, R
Supersymmetry and electroweak fine tuning

Low scale supersymmetry (SUSY) is a compelling solution to the electroweak hierarchy problem. However, increasingly strong limits on the masses of superpartners, first from LEP and now the LHC, mean that the simplest models require significant fine tuning. This thesis is dedicated to the study of a possible alternative low energy superpartner spectrum, natural SUSY, in which only superparticles directly involved in stabilising the electroweak scale are light, alleviating collider limits and potentially reducing tuning.
After reviewing how low scale SUSY is motivated by the hierarchy problem, we build a model of SUSY breaking and mediation that successfully generates a natural SUSY spectrum. This also suppresses the first two generation fermion Yukawas, and leads to small parameters in the hidden sector, which are required for successful SUSY breaking. A challenge in models of natural SUSY is raising the physical Higgs mass to 125 GeV, and we study the possibility that this could occur through the addition of a singlet to the theory. If stops are very light, the coupling of the singlet to the Higgs needs to be so large that it becomes nonperturbative before the scale of grand unification, raising the concern that precision gauge coupling unification may be upset. However, we find that this is not necessarily the case. Rather it is possible this could correct for the present &bsim; 3% discrepancy in the two-loop minimal supersymmetric model's unification prediction.
We then turn to the fine tuning in models of natural SUSY, emphasising that this should be measured with respect to the theory's ultraviolet (UV) parameters. We show that the first two generation sfermions can be made relatively heavy, beyond LHC reach, without introducing tuning. However, the gluino generates a significant tuning through the stops during the renormalisation group flow. As a result, there is no fine tuning benefit in reducing the stop masses below (50 - 75)% of the weak scale gluino mass, and we obtain strong lower bounds on the tuning of theories compatible with collider limits. We also study theories with Dirac gauginos, which have relatively low fine tuning even if the scale of mediation is high. Finally, we consider the effect of relaxing a common assumption and allowing the hidden SUSY breaking sector to modify the running of the visible sector soft masses. This may plausibly occur in realistic models and could dramatically reduce the fine tuning of SUSY theories.

Keywords: Supersymmetry
Advisor: March-Russell, J
Fertility decline in Japan since the 1970s

This study investigates the influence of socio-economic and attitudinal factors on recent changes in marriage and fertility in Japan. Using macroand micro-data (collected especially for this research), the study examines the validity of three main theories: (1) the New Home Economics theory; (2) Easterlin's theory; and (3) the ideational (or attitudinal) theory in detemining Japanese marriage and fertility behaviour.
The findings of this study show that socio-economic factors exert a substantial effect on Japanese marriage and fertility behaviour. More specifically, an increase in women's earning capacity raised their marriage age, lowered the level of their fertility, and lengthened their birth intervals. This evidence is in agreement with the New Home Economics theory. On the other hand, relative economic status also affected Japanese marriage and fertility behaviour. An improvement in the economic situation of young adults encouraged them to marry earlier, and to have more children. These findings support Easterlin's theory. However, comparing the two theories, the longitudinal trend of marriage and fertility pattern in Japan is better explained by the New Home Economics theory than Easterlin's theory. The level of women's wages had a relatively stronger impact on these patterns than their relative economic status.
The findings also reveal that attitudinal factors play a significant role in determining Japanese marriage and fertility behaviour. As women became less committed to traditional norms and values, they married later, had fewer children and lengthened their birth intervals. Likewise, the reinforcement of women's individualistic attitudes raised their marriage age, lowered the level of their fertility, and delayed their entry to parenthood. This evidence indicates that marriage and fertility pattern in Japan cannot be due entirely to socio-economic factors. Comparing socio-economic and attitudinal factors, the former had a greater influence on marriage and fertility behaviour than the latter. We conclude from the findings of this study that Japanese marriage and fertility behaviour are affected both by socio-economic and attitudinal (ideational) factors, but the influence of the latter is secondary.
Diving behaviour and activity patterns of the invasive American mink, Neovison vison

Semi-aquatic mammals have evolved to forage in both aquatic and terrestrial environments, and they generally lack locomotor specialisation for either. Having relatively unspecialised adaptations, some semi-aquatic species are generalist foragers, and their activity and diving patterns provide insight into constraints on their foraging behaviour.
The recent miniaturisation and improved accuracy of logging devices allow remote data collection from small (<1kg), shallow-diving species. The development of analytical methods has lagged behind technological advances (and techniques developed for fully aquatic animals do not account for the variability of behaviour typical of semi-aquatic animals and their switching between terrestrial and aquatic environments). I applied and developed novel analytical techniques to identify activities and diving patterns of a semi-aquatic mustelid, the American mink (Neovison vison), fitted with Time-Depth Recorders (TDRs). Using a hidden Markov model (HMM) algorithm allowed me to classify dives into three states to identify clustering, and describe sequential diving patterns by mink. TDRs were used to determine active/inactive periods on the basis of rapid TDR temperature changes, and this method was validated empirically. Having developed this methodology, I applied it to 18 datasets collected from 14 mink in lowland England. Terrestrial activity of mink was positively related to ambient temperature (across both sexes), however aquatic activity, especially diving, appeared to be more influenced by daylight than by temperature. Mink showed intersexual differences, with males being more nocturnal and more active on land, and females more diurnal, and more persistent in diving. There was considerable variability between sexes and individuals.
This is the first study to use HMM to classify the dives of a semi-aquatic animal, and the first to use TDR temperature records to identify mammalian activity patterns. These methods will be generally applicable to animals that make rapid transitions between environments and have thus far been difficult to study.

Keywords: biotelemetry
activity patterns
time-depth recorders
diving behaviour
American mink
Advisor: Macdonald, D
Hart, T
Passing through time: painting and cinema in the works of Julian Schnabel

THIS STUDY examines the intersection of painting and cinema through the oeuvre of American artist Julian Schnabel. A controversial painter who came to prominence in the contemporary art world of the eighties, the study begins by contextualizing Schnabel within the art critical debates of the period. Addressing and revising the perceived reputation of the artist, the first chapter re-positions Schnabel predominantly as an inheritor of various traits of post-war American painting, in particular the somatic, affective and existential treatment of the canvas characteristic of action painting.
The body of the study proceeds to compare the ways in which Schnabel’s cinematic practice borrows, extends and thus affirms many of his painterly approaches. Examining his four major film works (Basquiat, Before Night Falls, The Diving Bell and the Butterfly and Miral) in tandem with his paintings, these chapters plot major confluences between the two media, in particular Schnabel’s overall use of a subjective, phenomenological method. Crucially, this aesthetic approach is shown to be in the service of an existential as opposed to epicurean aim, as it is most overtly expressed in his use of the objet trouvé and the dedication.
The study ends by changing the vector of analysis to trace how Schnabel's foray into the cinema may have influenced the aesthetic of his paintings, and subsequently how a reproductive medium such as film is able to push the boundaries of painting, not necessarily to announce its death.
Ultimately, the goal of this study, beyond the monographic examination of a single artist, is to propose ways in which the medium of film has contributed to an evolving understanding of visual representation. For, unlike the modernist premise, the assumption is that it is precisely through the interaction and absorption of various formats that a medium can change, evolve and expand.

Keywords: visual arts
fine art
painting
film
cinema
Julian Schnabel
Advisor: Reed-Tsoscha, K
Studies of some volatile compounds of main group elements

Methylzinc tetrahydroborate, [MeZnBH4], has been prepared by two routes and the structure of the solid determined by X-ray crystallography to reveal helical polymers in which MeZn and BH4 units alternate. The latter functions as a bidentate ligand with respect to each of the adjacent metal atoms. Investigation by mass spectrometry and matrix isolation shows that the vapour consists of an equilibrium mixture of monomeric and dimeric species. The pattern of infrared bands for the monomer is characteristic of a bidentate BH4 group, a finding consistent with the results of DFT calculations. Disproportionation into [Me2Zn] and [Zn(BH4)2] is a common feature of the chemistry of methylzinc tetrahydroborate, although it has been possible to isolate and characterize the adduct [MeZnBH4.SMe2].
The reaction between [B4H10 and [Me2Zn] in the gas phase affords colourless acicular crystals of [(MeZn)2B3H7] in yields of ca. 10%. This compound has been characterized by chemical analysis and by NMR and vibrational spectroscopy. X-ray crystallography reveals that the product is a dimer, [(MeZn)2B3H7]2, featuring two distinct zinc environments. Two B3H7ZnNe ligands, formally derived from B3H8 by replacement of a µ2-H by a µ2-ZnMe unit, each function in a bis(bidentate) manner linking together two other MeZn centres through pairs of Zn-H-B bridges.
The structures of several aluminium tetrahydroborates in the solid phase have been investigated by X-ray diffraction. The structure of dimethylaluminum tetrahydroborate has been shown to consist of helical polymeric chains in which Me2-Al and BH4 units alternate. Here, too, the BH4 groups exhibit bidentate ligation with respect to each of the adjacent metal atoms, although the degree of interaction between the metal centre and the BH4 group is somewhat less than in [MeZnBH4 ]. Solid aluminium tris(tetrahydroborate) exhibits two phases with a transition temperature in the range 180-195 K. Each phase is made up of discrete Al(BH 4 )3 units, the principal differences relating to the packing of the individual molecules. In the a phase the Al(BH 4 )3 molecules display an angle of 78.2° between the AlB3 and Al(µ-H)2 planes and are disposed about a 21 crystallographic screw axis; in the ß phase the molecular units conform to D3h symmetry.
Dimethylindium octahydrotriborate, [Me2 lnB3 H8 ], has been synthesized by the reaction between trimethylindium and tetraborane(10) and characterized by chemical analysis and by NMR and vibrational spectroscopy. X-ray diffraction of a single crystal reveals that the solid consists of [Me2 lnB3 H8] units, although there is evidence of charge separation in the sense [Me2ln]+[B3 H8 ]- and of secondary interaction between terminal hydrogen atoms and adjacent indium centres. The infrared spectrum of the matrix-isolated vapour is consistent with a monomeric structure similar to that of [Me2 AlB3 H8].

Advisor: Downs, A
Downs, T