Machine tool’s productivity and ability to produce a component of the required quality is directly influenced by its dynamic stiffness at the tool center point. Lack of dynamic stiffness may lead to unstable regenerative chatter vibrations which are detrimental to the performance. The chatter vibrations are influenced by the changing structural dynamics of the machine as the tool moves along the tool path, resulting in position-varying machining stability of the system. Evaluation of these varying dynamics at the design stage is a complex process, often involving the use of large order finite element (FE) models. Complexity and computational costs associated with such FE models limit the analyses to one or two design concepts and at only a few discrete positions. To facilitate rapid exploration of several design alternatives and to evaluate and optimize each of their position-dependent dynamic behavior, a generalized bottom-up reduced model substructural synthesis approach is proposed in this thesis. An improved variant of the component mode synthesis method is developed and demonstrated to represent higher order dynamics of each of the machine tool components while reducing the computational cost. Reduced substructures with position-invariant response are synthesized at their contacting interfaces using novel adaptations of constraint formulations to yield position-dependent response. The generalized formulation is used to evaluate the position-dependent behavior of two separate machine tools: one with a serial kinematic configuration, and another with hybrid serial-parallel kinematics. The reduced machine model is verified against full order models and is also validated against measurements by including joint characteristics in the model. The effects of position and feed-direction-dependent compliances on machining stability are investigated by using a novel position and feed-direction-dependent-process-stability performance criterion that evaluates the productivity of machine tools in its entire work volume. Parameters limiting the target productivity levels are identified and modified; and, the complete dynamics are rapidly re-analyzed using the developed models. Optimal design modifications are shown to increase productivity by ~35%. The proposed methods in this thesis enable efficient simulation of structural dynamics, stability assessment as well as interactions of the CNC and cutting process with the machine tool structure in a virtual environment. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

In an attempt to reduce emissions and enhance the performance of a lean - burn, spark ignition engine, the effect of charge motion within the combustion chamber has been examined. The two most prominent charge motions are those of intake generated swirl and compression generated squish. A great deal of previous research work has focused individually on these charge motions, but very little has been done with respect to a detailed study of the combined effects of these phenomenon. The objective of this research is to determine if an optimum combination of squish and swirl intensity exists, and if so what the effects on performace and emissions are. The method by which this would be achieved was entirely experimental. The tests were run using a Ricardo - Hydra Research engine fuelled by natural gas. It required the design and construction of a swirl producing intake system followed by calibration on a steady flow test bench by means of a paddle- wheel anemometer. This resulted in swirl numbers in the range of 0 -1.6 at speeds in the range of 1000 - 2500 rpm. The variation in squish intensity was achieved by the insertion of piston crowns with the desired squish intensity. The squish was radial in nature produced by a bowl-in-piston configuration and a flat cylinder head. Squish ratios used were 0% , 30% , 50% and 70% which could be achieved using a 10.2:1 compression ratio. The testing was cycled through all possible squish and swirl combinations producing a set of emissions and performance data. Initially tests were conducted at WOT, using SAE correction factors for minor fluctuations in intake temperature and pressure. However a second set of part load tests conducted at an intake manifold pressure of 95 kPa produced more meartingful results due to less variations in intake conditions. definite optimization of engine torque and emissions was determined at various squish and swirl intensities and noted at all speed conditions. The effects were most prominent at higher relative air - fuel ratio (RAFR) where improvements in performance were up to 5%. Over the range of RAFR 1.0 - 1.4 benefits were found to vary from 1% - 5% in torque. The exhaust emissions results were less promising due to the increase in NO[sub x] as torque increased, and only a slight THC reduction with increased swirl intensity was noted. Noticeable trends were the benefit of a higher squish ratio as the charge became leaner, as well as when the speed was increased. Increased swirl intensity produced beneficial results with the higher squish requiring a lower swirl intensity to reach the optimum combination. A significant reduction in MBT timing was found as swirl no. was increased at all operating conditions. This reduction in MBT timing persisted after performance optimization had occurred indicating the beneficial effect of swirl on the initial burn time, but less benefit is obtained from the main burn time. The research project has brought to light a number of unexpected aspects of squish and swirl interaction, and has consolidated trends which were expected from previous research. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

Although it has been argued that indoor workers in fact make up the majority of the sex industry, most of the literature on the transition out of sex work has looked at street-based workers. This interview-based qualitative research project aims to fill that gap. As such, this thesis examines the trajectories, challenges and strategies of women who transitioned or are in the process of transitioning from criminalized indoor sex work (escorting, erotic massage and domination) to the mainstream labour market. Using Ebaugh’s role exit theory and Goffman’s conceptualization of stigma, intersectional feminist analysis and labour theory, I position the transition as a re-negotiation of self, involving conflicts in identity and class location. My findings suggest that the transition out of sex work is characterized by multiple, parallel work trajectories, wherein the women were successfully able to transfer skills they had acquired in sex work to the mainstream labour market.

Amidst a considerable body of literature on erotic dance, the voices of third parties, that is, the people who organize, supervise, manage or coordinate the labour of dancers, seldom appear. Yet, these third parties provide a setting and services that are vital to dancers’ entrepreneurial success. Furthermore, perceptions of third parties as exploitative and coercive perpetuate framings of erotic dance – and sex work in general – as harmful, which in turn invisibilize dancers’ work, as well as their skills, labour rights and grievances. Drawing from qualitative interviews with 15 third parties and 15 dancers, as well as regional regulatory texts, this dissertation seeks to trouble these stigmatic assumptions by shedding light on the work of third parties and the organization of labour in Ontario’s erotic dance sector. Mapping the occupational roles and relationships amongst third parties (e.g., managers, bouncers, disc jockeys) reveals the organizational structure and peripheries of the strip club. Through this map, we see how third parties together form the organizational structure, which operates as a parallel entity to dancers who, as independent contractors, are for the most part responsible for their own work activities and income. At the same time, because dancers and third parties must equally provide quality service to their shared customers, they are both interdependent on, and independent of, each other. This relationship ‘plays out’ through occupational and situationally adaptive performances, which reiterate and resist normative gender, racial, and class scripts to produce the ‘party’ environment of the strip club. Simultaneously ambiance and organizational culture, the ‘party’ environment shapes third parties’ and dancers’ occupational performances for, and perceptions of, each other. The continuity of performance required to maintain this environment also results in third parties reproducing certain regulatory discourses and mechanisms in their surveillance and rule enforcement practices, and disregarding and subverting others, which in turn impacts upon dancers’ safety. Third parties’ relationships with each other and dancers are also permeated by stigma, stereotypes and perceptions of risk that echo regulatory and broader social discourses. These findings demonstrate that third parties’ engagement with regulation and normative discourses are deeply inter-related and impact the quality of the services they provide to dancers. On this basis it is argued that the context and conditions of dancers’ labour will be improved by rethinking narrow-minded regulatory frameworks and social norms.

This study compares the morphological characteristics and swimming performances of a sympatric species pair of threespine stickleback in order to gain an understanding of the processes involved in their divergence. The fishes are young (13,000 years old), morphologically distinct, and inhabit different niches in the lake (Paxton Lake, Texada Island, British Columbia). Experiments were conducted to compare the steady swimming and escape fast-start performances of these fishes. I tested predictions of two hypotheses: 1) Selection has acted on the steady swimming ability of limnetics, and therefore I predicted that limnetics have greater steady swimming performance than benthics. 2) The specialization for steady swimming has compromised the fast-start performance of limnetics; consequently I predicted that benthics have greater fast-start performance than limnetics. As predicted, limnetics had greater steady swimming performance than benthics. The mean regression of the logarithm of fatigue time (F.T.) on swimming speed (U, in body lengths/second) for limnetics [Log (ET.) = 5.24 - 0.46U] was significantly higher (p <0.05) than that for benthics [Log (F.T.) = 3.77 - 0.43U]. The streamlined shape (to reduce drag), larger pectoral muscles (to provide power), and larger pectoral fin areas (to provide thrust) all contribute to the higher performance of limnetics. However, the fast-start performance of the two fishes was not significantly different for any linear parameter (pooled mean values for total fast-start: duration 0.049 s, distance 0.034 m, maximum velocity 1.10 m/s, and maximum acceleration 133.9 mIs2). With large, caudally placed fins limnetics achieved equal fast-start performance to the deeper bodied benthics. The prevailing view of functional morphology in fishes is that adaptations for high performance in one swimming mode compromise those for high performance in the other swimming modes. For example, optimal characteristics for fast-starts are thought to trade-off against optimal traits for manoeuvering and steady swimming. However, both of the sticklebacks studied here were capable of good manoeuverability and fast-start performance. The propulsive systems of these fish aie decoupled; consequently there is no trade-off between adaptations for these swimming modes. Limnetics achieved high performance in all three swimming categories with no compromise between good steady swimming and fast-start ability. The differences in prolonged swimming performance are linked to morphological and habitat differences. I suggest that selection due to differential resource use has lead to divergence of body form and therefore of steady swimming performance. However, the results of this study also suggest that selection from predators has lead to maintenance of high performance in fast-start swimming. Predation pressure is probably similar on these fishes; consequently selection would favour traits which enhance high escape fast-start performance in both species. / Science, Faculty of / Zoology, Department of / Graduate

Molecular-beam mass spectrometry (MBMS) is a technique that is used to measure stable and radical species within flames, and thus it is a strong tool for understanding the formation and destruction pathways of precursors to PAH and soot. Using MBMS and modeling techniques, three well-chosen premixed flat flames have been characterized. Fuel-lean ethylene flames with and without added allene were mapped to help elucidate the C3H3 self-combination route to benzene formation, and a cyclohexane flame was characterized due to the abundance of cyclohexane within real fuels such as gasoline. Benzene is the precursor to PAH and soot whose formation is the rate-limiting step, and thus knowledge of its formation route is paramount. The flames characterized include an undoped fuel-lean (&phis; = 0.70), C2H4/O2/56.4% Ar flame (30.00±0.01 Torr and ub-300 = 30.6 cm/s), an allene-doped fuel-lean (&phis; = 0.69), 0.19 % C3H4/C2H 4/O2/56.54 % Ar flame (30.00±0.01 Torr and ub-300 = 30.6 cm/s), and a stoichiometric (&phis; = 1.00) cyclohexane/O2/32.5% Ar flame (30.00±0.01 Torr and ub-300 = 35.0 cm/s). Mole fraction profiles of 31, 35, and 70 stable and radical species were measured within the three flames, respectively. They are modeled with overall good agreement between the model and data. Comparison of both fuel-lean ethylene flames shows that benzene was detected in the allene-doped flame but not in the undoped ethylene flame, strongly suggesting the importance of C3 routes to benzene. Reaction path analysis showed that benzene in the allene-doped flame is mainly formed through propargyl self-combination as described by the kinetics of Miller and Klippenstein (2003). Examination of the cyclohexane flame showed high concentrations of benzene. A reaction path analysis showed that benzene is mainly formed instead by the dehydrogenation of cyclohexane. Experiments done at the Advanced Light Source of Lawrence Berkeley National Laboratory show that the isomeric C6H6 composition in the allene-doped flame consisted of 20% fulvene, 45% benzene and 35% 1,5-hexadiyne, while the cyclohexane flame consisted of 99.5% benzene and 0.5% fulvene. This difference in isomeric composition strongly points to the difference in benzene formation pathways in the two fuels.

Cross-listing refers to firms listing their equities on more than one stock exchange. Cross-listing is an interesting topic of international finance. This is because along with the deeper integration of the global financial market, we should see lesser importance of geographic factors. Thus, the motivations and effects of listing a firm on exchanges of different regions should have essential economic implications. The reputation bonding hypothesis suggests that U.S. cross-listing improves the information environment of a firm because of the higher disclosure standard and more analyst coverage. The legal bonding hypothesis argues that U.S. cross-listing improves the investor protection and corporate governance of a firm since the firm is under more stringent law and regulation. The firm growth hypothesis points out that U.S. cross-listing lowers the external capital cost of a firm and thus enables the firm to achieve a higher growth rate. Using a sample with 12532 firms of 23 developed regions from 2006 to 2011, this thesis tests the three hypotheses of cross-listing. Firstly, my empirical results show that a cross-listing on the U.S. exchanges improves the equity returns predictability of institutional investors. I find a stronger positive correlation between the changes in institution ownership level and future equity returns of U.S. cross-listed firms. This suggests that the information environment is improved after a U.S. cross-listing. However, the improvement in information environment exists only in non-crisis period. Secondly, the results support the firm growth hypothesis. The U.S. cross-listing event only has a positive effect on equity returns of firms with younger age and lower dividend yield. This effect becomes less obvious during the crisis period. Thirdly, the legal bonding effect of U.S. cross-listing only exists during the crisis period, when the financial market is volatile. During the crisis period, a U.S. cross-listing increases the equity returns of the firms form non-common-law regions, but not the firms from common-law regions.

Bibliography: pages 272-287. / This study attempts an analysis of the form and content of the opposition of the Roman Catholic Church in South Africa to the policy and practice of apartheid during the period 1948-1989. It is argued that the divisions, tensions and contradictions of the Catholic Church reflect the socially divided character of the broader society. It is suggested that some of the policies, teachings and social practice of the South African Catholic Church serve to reproduce and reinforce the existing societal relations of domination, thus contributing to the hegemony of the dominant social group, while others undermine the same and point toward a transformation of social relations in a democratic society. In some instances the Church has contributed to the nascent hegemony of the dominated group. Literature focusing on the Catholic Church during times of social upheaval is reviewed. Recent analyses of the role of the Christian Churches in apartheid South Africa are considered. Various approaches to the Sociology of Religion are discussed and the relevance of a contextual approach to the analysis of the Church is argued. Gramsci's concept of hegemony as a tool of political analysis is discussed. A brief .historical overview of the Catholic Church in South Africa is given. It is contended that the Catholic Church in South Africa must be understood in terms of its colonial, missionary and racist history. An ecclesiological overview of the Roman Catholic Church in terms of its - history, traditions, organization, authority structures, governing procedures and beliefs is sketched. The ·social Teaching' of the Catholic Church during the twentieth century is outlined. The importance of the Second Vatican Council, the emergence of the Theology of Liberation and the increasing centrality of social justice in Church teachings is discussed. The implications of these developments for the pastoral practice of the Church is emphasized. The response of the Catholic Church to the introduction and implementation of 'separate development' is considered. Content analysis is used as a research method. The study therefore falls within the realm of hermeneutic or interpretative sociology. The gradual transition from an attitude of paternalism to committed involvement in the anti-apartheid struggle is traced. The Catholic Church's response to the Bantu Education Act, which was the primary focus of its opposition to apartheid in the 1950's, is evaluated. The challenge of the Black Consciousness movement is acknowledged. It is argued that the realities of apartheid society have had a profound impact on the Church, severely compromising its unity. The related processes of reform, repression and resistance are examined. It emerges that while the Church's championship of human rights has been unequivocal, its support for some of the strategies employed in the struggle against apartheid has been more tentative. It is argued that the Catholic Church's participation in the anti-apartheid struggle has facilitated a growth in ecumenism and increased contact with secular organizations. The Catholic Church has become part of a broad anti- apartheid alliance. It is suggested that while there have been important changes in the Church's self-understanding and perception of its role in, and pastoral mission to, society, these changes have been uneven and ambiguous. They have not been reflected throughout the Church and have underlined the divisions within the Church. There has been considerable reluctance on the part of many white Catholics to endorse the anti-apartheid stance of the hierarchy. However, the S.A.C.B.C.'s commitment to social justice is in tune with modern Catholic social teaching. Finally, it is argued that the Catholic Church has challenged white domination and undermined the hegemony of apartheid in South African society.

This thesis explores the use of language, myth creation, and the development of American civil religion to construct a national identity. It analyzes the role of religious language in imagining an identity for the American people, with Protestant Christianity being a driving force for this rhetoric. Throughout this thesis, I argue that specific historical figures have become symbols of American identity, creating an American cult that venerates these figures as sacred icons. This thesis traces the historical development of thought as it relates to American political figures taking on mythical and legendary status in the minds of the citizens. The role of monuments and memorials in Washington, D.C., as capsules into the past and symbolic representations of what is essential to the American people, is also explored. I argue that monuments and memorials have artistic perspectives and use specific imagery that shows how the designers want their audience to view and interpret the events and people who are the subject of the piece and how notions of national identity are projected onto monuments, memorials, and symbols. The thesis also examines the growing phenomenon of far-right nationalism in the United States and how President Trump used populism and rhetoric of American civil religion to strengthen his support. I also explore the variations of patriotic participation through protests by Colin Kaepernick and the Black Lives Matter Movement showing the diverse nature of national identity and civic contribution. The thesis also delves into the importance of the military in the United States and how soldiers have become a symbol of American patriotism and identity. By highlighting the role of religion, language, and mythology in shaping national identity, this thesis sheds light on the complex interplay between culture, history, and identity in the United States.

High-pressure die casting of semi-solid aluminium-silicon alloys is used in the automotive industry to manufacture components, like housings, brackets, and bars. It is commonly known that during high-pressure die casting, defect bands may be created that follow the contour of the component surface. These bands consist mainly of a eutectic phase. This phenomenon is also observed in semi-solid metal slurry high-pressure die casting. These bands could lead to premature failure of the component in service. The origin of these bands is not fully understood and so this research focuses on investigating these bands and their origins further. A series of casting trials were conducted with varying plunger velocity. Subsequent investigation using optical and scanning electron microscopy showed that a change of the plunger velocity alters the number of bands present in the samples. Energy dispersive X-ray spectroscopy revealed that a measurable difference in aluminium quantity across the band was noticed and it was postulated that aluminium migrates towards the component centre. Therefore, different mechanisms responsible for particle migrations found in literature were investigated and assessed quantitatively using experimental data and information from published literature. It was found that the Saffman lift force and the Mukai-Lin-Laplace effect were the mechanisms that were most likely to cause such a migration of aluminium. Further experimental investigation is recommended to identify which of the two mechanisms is ultimately responsible for the migration and to optimise the high-pressure die casting procedure to minimise defect band formation. / Produktion av högtrycksgjutning av halvfasta aluminium-kisellegeringar används i fordonsindustrin för att tillverka komponenter, som exempel till kåpor, konsoler och stag. Det är allmänt känt att defektband kan formas under högtrycksgjutning som följer konturen av komponentytan. Dessa band består huvudsakligen av eutektisk fas. Detta fenomen har också observerats vid högtrycksgjutning produktion av halvfast slurry. Potentiellt kan dessa band leda till en försämring av komponentens mekaniska egenskaper och resultera i ett förtida brott. Ursprunget av dessa band är inte helt kartlagda och det är därför viktigt att fokusera ytterligare på denna forskning och att undersöka dessa band och deras ursprung. En serie med gjutningsförsök genomfördes med varierande kolvhastighet. Efterföljande undersökning med optisk- och svepelektronmikroskopi visade att en förändring av kolvhastigheten förändrar antalet band som finns i proverna. Energidispersiv röntgenspektroskopi avslöjade en mätbar skillnad i aluminiumkvantitet över bandet, och det antogs att aluminium migrerar mot centrum av komponenten. Därför undersöktes och utvärderades olika mekanismer som ansvarar för partikelmigrationer som finns att finna i litteratur med hjälp av experimentella data och information från publicerad litteratur. Det visade sig att Saffman lyftkraft och Mukai-Lin-Laplace effekten var de mekanismer som mest troligen orsakade migration av aluminium. Ytterligare experimentella försök rekommenderas för att identifiera vilken av dessa två mekanismerna som i slutändan är ansvarig för migrationen. Detta för att optimera gjutningsprocessen och därmed minimera uppkomsten av defektband.