13,269 results for UC Research Repository

  • Urban Tree Diversity - Taking stock and looking ahead

    Morgenroth, J.; Östberg, J.; Konijnendijk van den Bosch, C.; Nielsen, A.B.; Hauer, R.; Sjöman, H.; Chen, W.Y.; Jansson, M. (2016)

    Journal article
    University of Canterbury Library

    The first International Conference on Urban Tree Diversity hosted in June 2014 by the Swedish University of Agricultural Science in Alnarp, Sweden highlighted the need for a better understanding of the current state of urban tree diversity. Here we present and discuss a selection of urban tree diversity themes with the intention of developing and sharing knowledge in a research area that is gaining momentum. We begin by discussing the specific role of species diversity in ecosystem service provision and ecosystem stability. This is followed by exploring the urban conditions that affect species richness. Having determined that many ecosystem services depend on urban tree species diversity and that urban environments are capable of supporting high species diversity, we conclude by addressing how to govern for urban tree diversity.

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  • Politics as creative pragmatism: rethinking the political action of contemporary university students in Aotearoa New Zealand

    Nissen, Sylvia Esther (2017)

    Doctoral thesis
    University of Canterbury Library

    This thesis reconsiders the political action and agency of contemporary university students in Aotearoa New Zealand. Although the twenty-first century has witnessed a global growth in student protest (Brooks 2017), there does not seem to have been a noticeable increase in political activism among New Zealand students, with critics variously labelling students as apathetic, selfish, distracted or disinterested (Green 2015; McClennen 2015). However, this thesis argues there is more to contemporary New Zealand student political action and attitudes than has been previously understood. The political attitudes of New Zealand students are examined through 70 in-depth interviews with students at New Zealand’s eight universities, supplemented by observation in the period 2014 to 2015. The thesis provides a conceptual framework of ‘3 Ds’ for understanding the experiences of contemporary students that inform their political action: desires for different types of politics, demands of contemporary university environments and doubts in an era of political ambiguity. This framework challenges and extends dominant theoretical explanations of student political action in the early twenty-first century, specifically theories of agency, political economy and social network analysis. In advancing a ‘3 Ds’ framework, this thesis also identifies a particular form of political agency emerging among New Zealand students that can be synthesised and understood through a concept of ‘creative pragmatism’. Creative pragmatism is a term advanced here to describe a ‘realistic’ orientation among students towards their social world, and their creative but cautious negotiation of political environments. The term also acknowledges a willingness amongst students to rethink how they engage politically, while retaining a strong ideal that a ‘different politics is possible’.

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  • Novel N-heterocyclic carbene ligands for use in asymmetric catalysis

    Kerr, Will (2017)

    Doctoral thesis
    University of Canterbury Library

    This investigation sought to establish new and adaptable methods for incorporating an enantiomeric component into NHC ligands and to develop novel precatalyst prototypes capable of asymmetric induction for use in transition metal mediated catalysis. This thesis details the fulfilment of these objectives through the design, synthesis and characterisation of forty‐eight previously unreported compounds including twenty‐six new NHC proligands and fourteen NHC complexes. NHC derivatives of the chiral mono‐terpene camphor are explored in Chapter 2, primarily through the synthesis of a series of bornyl‐acetamide linked NHC proligands, demonstrating expedient incorporation of an enantiomeric moiety by acetamide linkage. Bornyl‐acetamide NHC complexes of Ag(I), Pd(II), Pt(II) and Ru(II) are studied and structural elucidation supported by comparison with the Pd(II) and Pt(II) complexes of an achiral cyclohexyl‐acetamide analogue (Chapter 3). Chapter 4 introduces metallo‐ NHC proligands derived from imidazo[4,5‐f][1,10]phenanthroline, capable of backbone coordination of a ruthenium‐polypyridine component. Alternatively, use of an acetamide‐tether provides metallo‐NHC proligands of 5‐acetamido‐1,10‐ phenanthroline and 4‐acetamido,2,2’‐bipyridine (Chapter 5). Also outlined is the synthesis of several remarkable hetero‐dinuclear NHC complexes in addition to the effective enantiomeric resolution of a metallo‐NHC proligand. The performance of selected systems in an asymmetric Suzuki coupling is examined in Chapter 6. Several of the organic‐NHC ligands elicit comparable activity to reported systems, however, product formation is not observed when using an acetamide‐linked metallo‐NHC ligand. This is most likely related to amide‐group coordination which occurs readily for the metallo‐NHC ligands compared with the bornyl and cyclohexyl analogues. Such conclusions are supported by the comprehensive structural elucidation of all NHC complexes prepared in this thesis, providing evidence for the behaviour of catalytic intermediates involving these ligands.

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  • Geotechnical aspects of the 2016 Kaikōura Earthquake on the South Island of New Zealand.

    Stringer ME; Bastin S; McGann C; Cappellaro C; El Kortbawi M; McMahon R; Wotherspoon L; Green R; Aricheta J; Davis R; McGlynn L; Hargraves S; Van Ballegooy S; Cubrinovski M; Bradley B; Bellagamba X; Foster K; Lai C; Ashfield D; Baki A; Zekkos A; Lee R; Ntritsos N (2017)

    Journal article
    University of Canterbury Library

    The magnitude Mw7.8 ‘Kaikōura’ earthquake occurred shortly after midnight on 14 November 2016. This paper presents an overview of the geotechnical impacts on the South Island of New Zealand recorded during the postevent reconnaissance. Despite the large moment magnitude of this earthquake, relatively little liquefaction was observed across the South Island, with the only severe manifestation occurring in the young, loose alluvial deposits in the floodplains of the Wairau and Opaoa Rivers near Blenheim. The spatial extent and volume of liquefaction ejecta across South Island is significantly less than that observed in Christchurch during the 2010-2011 Canterbury Earthquake Sequence, and the impact of its occurrence to the built environment was largely negligible on account of the severe manifestations occurring away from the areas of major development. Large localised lateral displacements occurred in Kaikōura around Lyell Creek. The soft fine-grained material in the upper portions of the soil profile and the free face at the creek channel were responsible for the accumulation of displacement during the ground shaking. These movements had severely impacted the houses which were built close (within the zone of large displacement) to Lyell Creek. The wastewater treatment facility located just north of Kaikōura also suffered tears in the liners of the oxidation ponds and distortions in the aeration system due to ground movements. Ground failures on the Amuri and Emu Plains (within the Waiau Valley) were small considering the large peak accelerations (in excess of 1g) experienced in the area. Minor to moderate lateral spreading and ejecta was observed at some bridge crossings in the area. However, most of the structural damage sustained by the bridges was a result of the inertial loading, and the damage resulting from geotechnical issues were secondary.

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  • The Frequency and Type of Talk in Three New Zealand Families at Dinnertime

    Indugula, Pragnya (2017)

    Masters thesis
    University of Canterbury Library

    Language is an important aspect of communication and a parent is a child’s first teacher. The more variety of talk the parents use, the more opportunities children will get to imitate that language and therefore widen their vocabulary. This study was based on the work of Hart and Risley (1995). The purpose was to observe the frequency and type of talk, the number of encouragements and discouragements, and the non-verbal interactions that occurred at the homes of dinnertime in three New Zealand middle and high income Families. Each family consisted of two adults and two children aged between 3 and 6 years. Data was collected via videotape. The results indicate that the higher income families had a higher frequency of talk and used more variety of talk. Contradictory to previous studies, the middle income family used more encouragements than discouragements with their children while the higher income families used more discouragements to encouragements. The middle income family also used the lowest number of non-verbal interactions. There was little exploratory talk included in the dinnertime conversations between family members. An implication of these findings is that, in order for children to extend their vocabulary, families could use more exploratory talk so that this could occur.

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  • The Power of Robot Groups with a Focus on Persuasive and Linguistic Cues

    Brandstetter, Jürgen (2017)

    Doctoral thesis
    University of Canterbury Library

    Today the HRI community generates a lot of knowledge on how one robot affects one human, and how one robot affects multiple human listeners. Much less knowledge is available on how robots affect the human language and how this language change can affect human attitudes and behaviours. This language effect is of particular interest for when we get into a situation where a major part of the human population has robots, as we are now experiencing with the ubiquity of smartphones. In this case, the questions are: What happens if all robots were to use the same words? For example, when they all use the same source as their dictionary. Will robots be able to affect the word choices of the human population, and what are the implications of connotation-laden vocabulary? Even more interesting, will this word choice affect the attitudes and behaviours of the human population? Through all those questions a central question for this thesis emerged: "Are Robots able to influence a group of people via the usage of language?" To find out if this might be possible, we developed three connected experiments. In the first, the effect of peer pressure on humans created by robots is explored, focusing on how this peer pressure affects the language of a person. To see if and how this influence of robots works, the effect of the robots was compared against that of human actors. The results of the ex- periment showed that the actors could indeed influence the participants as predicted, however, no such influence could be shown by the robots. It was concluded that the reason the robots did not affect the humans was that the participants did not feel that they belonged to the robots group. In the second experiment, a robot and human group setting was created. In this experiment, the robot tried to influence the human language. Important here to mention is that the experiment measured if the language of participants was affected by the robot influence, even after the interaction and without any robot in the room. It was also mea- sured if the word chosen by the robot had an influence on how a person would perceive the discussed object. The outcome of the experiment was successful, and showed that the group building worked and the robot was able to affect the human language, even after the interaction was over. It further showed that robots were able to affect the hu- mans attitude toward objects simply by using positive or negative connoted synonyms for a particular object. In the third and last experiment, the question was: Can many robots affect the language of a whole human population? To answer this, different parameters were measured: How many humans need robots so that the robots could manipulate the whole human populations language? And does it matter which persons in the human population will get a robot - whether it be a person who is very well connected or a person who is poorly connected, for example? Since we are currently not in a time where a huge number of people actually have robots, a simulation was created. The outcome of the simulation was that on average only 11% of the human population needed robots to affect the language of 95% of the human population. Finally, to further deepen the knowledge on how simple language change can affect human attitude and behaviour a literature review is added. This review focuses particularly on persuasion via language, which includes effects like gender neutral versus non-gender neutral language. The conclusion of this thesis is that in certain situations, a group of robots is able to affect the language, and in turn the behavioural responses, of the majority of the human population.

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  • The European Union's rights-based approach: helping Pacific communities to overcome gender-based violence?

    Brown, Eva (2017)

    Masters thesis
    University of Canterbury Library

    Gender equality is a fundamental human right and consequently the foundation to achieving sustainable development. As human beings, women and girls, men and boys, are all entitled to living a life of dignity, free of want or fear. Unfortunately, many societies around the world continue to be organised in ways that discriminate individuals on the basis of their gender. Gender-­‐based violence is a perverse manifestation of gender inequality that directly affects many women and girls in societies around the world and is a detrimental factor to achieving sustainable development. The European Union (EU) is a leading advocate for human rights and gender equality on the global stage. In an effort to strengthen and integrate human rights into development, the EU followed other development actors in underlining its commitment to applying a rights-­‐based approach (RBA) to all development cooperation. Meaning that human rights are both incorporated as a means and as a goal of development policies and projects. As a donor in the Pacific, the EU has identified gender equality and the particular issue of gender-­‐based violence as focal areas. This study focuses on the impact of the EU’s RBA on the capacity of civil society to promote gender equality and counter gender-­‐based violence in Melanesian societies. Dominant patriarchal societies tend to tolerate gender-­‐based violence, creating a challenging environment to promote gender equality and women empowerment. Furthermore in these particular societies, human rights and culture are perceived as conflicting concepts. Local civil society is therefore a vital partner for the EU in order to reach local communities and influence policy outcomes. This study undertakes a type of impact assessment in order to identify how an EU RBA is filtering down to the community-­‐level in Melanesia. Semi-­‐structured interviews with leaders of local civil society and policy-­‐makers in Suva, Fiji provided the study with an insight into what the EU is actually doing on the ground. A desk-­‐based analysis of EU policy documents including regional and national indicative programmes for Melanesia were mapped and cross-­referenced with interview data to identify potential gaps between policy rhetoric and action at a community and civil society levels. As an enabler of development, the EU and their newfound approach, have the potential to strengthen civil society capacity to overcome barriers in advocacy for women’s rights. However despite positive intentions in policy, impact on the ground is very much determined by community engagement and is potentially personality-­‐driven. This study investigates the role of the EU both in rhetoric and action in an effort to draw attention to the possible gaps between theory and practise in EU development in the Pacific.

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  • Relative Brauer groups of torsors of period two

    Creutz, B. (2016)

    Journal article
    University of Canterbury Library

    We consider the problem of computing the relative Brauer group of a torsor of period two under an elliptic curve. We show how this problem can be reduced to finding a set of generators for the group of rational points on the elliptic curve. This extends work of Haile and Han to the case of torsors with unequal period and index. Our results also apply to torsors under higher dimensional abelian varieties. Several numerical examples are given.

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  • Numerical Modelling of the Micromechanical Behaviour of Catastrophic Long Run-Out Rock Avalanches

    de Graaf, Kim L. (2016)

    Doctoral thesis
    University of Canterbury Library

    Long runout rock avalanches occur in steep mountainous areas, typically due to the effects of heavy rain, freeze-thaw cycles or seismic shaking among others. The runout is renowned for travelling a large horizontal distance in comparison to the vertical fall height and the extent is largely determined by the volume of source rock. The material dynamically disintegrates during runout depositing angular fragments surrounded by rock flour and preserving the original stratigraphy. The propagation mechanism of long runout rock avalanches has been debated for over a century. The majority of the mechanical theories suggested to explain the long runout behaviour may focus on a particular aspect noted from one or several events, however, do not properly explain the angularity of the grains within the deposit or the possible internal behaviour of the avalanche. This thesis aims to investigate the fragmentation theory of rock avalanche propagation from a soil mechanics perspective. The rapid application of load and high speed shearing is postulated to cause the dynamic fragmentation of debris, where the rapid movement of fragments and fines reduces effective stress and therefore friction, increasing mobility. Material then moves rapidly until all available kinetic energy has been dissipated or no further dynamic fragmentation can occur. The potential influence of multiple dynamic fragmentation events occurring at once provides useful information for the prediction and extent of rock avalanches, along with micro scale behaviour of rock under rapid loading and high speed shearing for mining purposes. Discrete Element Modelling (DEM) via the use of PFC3D has been utilised to undertake oedometer and shear box testing of idealised samples. These tests are used to represent dominant mechanisms that occur in the two key periods of a long runout rock avalanche — the fall (modelled by high strain rate oedometer testing) and the runout (modelled by high speed shear box testing). Synthetic and fully calibrated bonded particle models are used to investigate the response of rock boulders under these conditions. The calibrated materials of sandstone, weak chalk and extremely weak chalk were chosen to represent typical large and small scale long runout events. Numerical oedometer testing reveals that the application of high strain rates normal to the ground surface produces fast and significant breakage along with a noticeable response in kinetic energy and a reduction in mobilised friction. The additional kinetic energy remains available in the system for a longer period of time than that produced by semi-static strain rates. The high strain rate oedometric tests suggest that dynamic fragmentation occurs under fast loading rates. It is plausible that dynamic fragmentation in a sturzstrom due to rapid loading at the transition point from fall to runout can enhance mobility. High speed shear box testing indicates a significant rise in normal and shear stresses resulting in intense crushing and dilation rather than dynamic fragmentation. Kinetic energy produced from breakages is quickly dissipated through dilation and does not remain in the system long enough to influence mobility. The majority of the shearing is likely to occur in a small zone at the base of the debris. The minimal mixing of layers during the shear testing and substantial dilation supports the observed preservation of stratigraphy and increase in debris volume seen at the majority of sturzstrom sites.

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  • Transport infrastructure performance and management in the South Island of New Zealand, during the first 100 days following the 2016 mw 7.8 “Kaikōura” earthquake.

    Davies AJ; Sadashiva V; Aghababaei M; Barnhill D; Costello SB; Fanslow B; Headifen D; Hughes M; Kotze R; Mackie J; Ranjitkar P; Thompson J; Troitino DR; Wilson TM; Woods S; Wotherspoon L (2017)

    Journal article
    University of Canterbury Library

    At 00:02 on 14th November 2016, a Mw 7.8 earthquake occurred in and offshore of the northeast of the South Island of New Zealand. Fault rupture, ground shaking, liquefaction, and co-seismic landslides caused severe damage to distributed infrastructure, and particularly transportation networks; large segments of the country’s main highway, State Highway 1 (SH1), and the Main North Line (MNL) railway line, were damaged between Picton and Christchurch. The damage caused direct local impacts, including isolation of communities, and wider regional impacts, including disruption of supply chains. Adaptive measures have ensured immediate continued regional transport of goods and people. Air and sea transport increased quickly, both for emergency response and to ensure routine transport of goods. Road diversions have also allowed critical connections to remain operable. This effective response to regional transport challenges allowed Civil Defence Emergency Management to quickly prioritise access to isolated settlements, all of which had road access 23 days after the earthquake. However, 100 days after the earthquake, critical segments of SH1 and the MNL remain closed and their ongoing repairs are a serious national strategic, as well as local, concern. This paper presents the impacts on South Island transport infrastructure, and subsequent management through the emergency response and early recovery phases, during the first 100 days following the initial earthquake, and highlights lessons for transportation system resilience.

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  • Locating Ourselves: An analysis and theoretical account of strategic practices of identity and connection in Aotearoa/New Zealand’s Pacific news media

    Ross, Tara (2017)

    Doctoral thesis
    University of Canterbury Library

    This thesis sets out to explore the under-researched field of New Zealand’s Pacific media to yield insights into Pacific media and audiences, and what makes media ‘ethnic’. It draws on theories about identity, practice and the audience, and a qualitative multi-method approach grounded in Pacific people’s actual voices and practices. It breaks new ground on Pacific media, which have not been studied in such depth or from a broad audience perspective, and reveals that Pacific media are highly diverse and face considerable challenges, including a significant demographic shift among their intended audiences. It adds to the scholarship on ethnic media, first, by revealing tensions within Pacific media practice (including a tension between Pacific and journalistic fields), which helps to problematise scholarly assumptions about ethnic media, and, second, by suggesting a model of Pacific media as a media of identity negotiation. It finds that Pacific media are powerful symbolic referents of Pacific identity and key sites where producers and audiences negotiate community and belonging through various locative practices, often in ways that establish tighter connections than in mainstream media. This is notwithstanding that the range of ‘Pacific’ identities represented in Pacific media can be narrow and risk excluding New Zealand-born Pacific youth. This study further suggests that societal-wide ideas of journalism and publicness are more central to Pacific audiences’ assessments of Pacific media than may have been accounted for to date. Pacific groups are positioned narrowly in New Zealand publicness, including by funders’ whose focus on Pacific media in terms of ethnicity and culture tends to overlook audiences’ demand for in-depth news, innovation and diverse content. This study concludes that viewing ethnic media within categories of ethnicity or culture (as do funders, scholars and, often, media producers) risks exaggerating the ‘otherness’ of ethnic minority groups. Instead, we need to reorient our efforts to categorise ethnic media away from a fixation on difference and towards people’s actual media practices to better reflect people’s multiple and complex realities.

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  • Listening to disordered speech results in early modulations of auditory event-related potentials

    Theys C; McAuliffe MJ (2017)

    Conference Contributions - Published
    University of Canterbury Library

    In the last decade, research on motor speech disorders has increasingly taken into account the bidirectionality between speaker and listener. Listening to disordered speech (e.g., dysarthria) may result in substantial phonemic uncertainty. In turn, a larger set of potential word target candidates may be activated—contributing to intelligibility deficits. To resolve this uncertainty, a combination of both bottom-up and top-down processes are thought to play a role (Liss, 2007). The goal of the present study was to investigate the contribution of these processes by analysing listeners’ neurophysiological processing when listening to dysarthric speech. Thirty healthy native English speakers (12 males, 18-44 years) participated in a speech perception experiment while undergoing 32-channel EEG recording. Similarly to Obleser and Kotz (2011), we focused on the auditory N100 as a marker for earlier sensory processing and the N400- like peak representing information on later cognitive-linguistic processes. Participants listened to 55 moderate hypokinetic dysarthric sentences and 55 control sentences. The experiment was repeated one week later to investigate the effects of repeated exposure to disordered speech. The amplitudes and latencies of the event-related potentials over Cz were analysed. Repeated measures GLM statistics of the N100 with speech type (dysarthria vs. control) and test session as independent variables showed a main effect of speech type, with increased amplitude (Fampl(28)=12.18, p<.01) and decreased latency (Flat(28)=6.77, p=.02) when listening to dysarthric versus control speech. There was no significant main effect of test session or interaction effect. In contrast, no significant effects of speech type and test session were observed on the amplitude of the N400-like peak. For latency, only a significant interaction effect was present (Flat(28)=4.16, p=.05), evidenced by decreased latency for dysarthric sentences during the first test session, and the reverse during the second session. The N100 results show that the quality of the auditory signal in naturally degraded dysarthric speech influences early sensory auditory processing, indicating an increase in the initial allocation of neurophysiological resources (Obleser & Kotz, 2011). The N400 latency results show that later, more cognitive-linguistic processes are not only influenced by the degradation of the signal itself but also by the amount of exposure to that signal, a finding consistent with previous behavioural research on dysarthric speech (Borrie et al., 2012).

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  • Reducing codebook loss with reconfigurable receive antennas

    Afsheen, U.; Smith, P.J.; Martin, P.A. (2016)

    Journal article
    University of Canterbury Library

    In this study, a reconfigurable antenna codebook feedback (FB) scheme is investigated to reduce precoding codebook loss without increasing the number of FB bits. Analysis and simulations show that increasing the number of receive antenna states (S) has the same effect as codebook size expansion when the codeword and state selection is based on minimising the distance between channel and codeword. In addition, the authors propose an optimum selection approach. The signal to noise ratio (SNR) and rates achieved with perfect FB in a traditional nonreconfigurable antenna system, can be exceeded with only S = 2, using the proposed optimum selection. In fact doubling S gives an approximate SNR gain of 40% compared with S = 1. The authors also consider the effects of channel estimation errors and correlated antenna states. The authors show that the performance losses due to correlation can be quantified with a simple closed form result.

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  • Effects of sheep grazing exclusion on alpine tall tussock grassland

    Norton, D.A.; Young, L.M. (2016)

    Journal article
    University of Canterbury Library

    Substantial areas of alpine tall tussock grasslands are being retired from grazing as part of Crown pastoral lease tenure review because of the perceived negative impact of grazing livestock. However, relatively little is known about the effect of sheep exclusion on these grasslands. We analysed data from five grazing exclosure plots over a 6-year period to examine the effect merino sheep have relative to hares and rabbits in alpine tall tussock grasslands used for summer grazing. Unfortunately, because of snow damage to fences, we were unable to detect any significant hare and rabbit effects. Over the time of this study, there was no evidence for significant vegetation recovery after exclusion of sheep grazing. This may be because of other grazing animals in the system, or the low stocking rates and non-random grazing behaviour of merino ewes. There was, however, a significant increase in the cover of exotic herbs Pilosella officinarum and P. praealta and a significant decrease in the cover of native tussocks Festuca novae-zelandiae and Poa colensoi regardless of grazing exclusion. While this pattern has been previously documented in studies at lower elevations and usually with a history of burning, our results demonstrate that alpine grasslands with no burning history can also be invaded by Pilosella spp. over relatively short time frames. Replicated grazing exclosure trials such as the one described in this paper are important for providing objective information on both long-term trends in vegetation composition and the impacts of grazing animals in alpine grasslands as a basis for making informed decisions on their future management.

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  • Some aspects of molybdenum halide chemistry

    Gainsford, G.J. (1969)

    Doctoral thesis
    University of Canterbury Library

    Chemical and X-ray crystallographic studies of molybdenum(II) halides, which are based on the well-known (Mo₆C1₈)⁴⁺ cluster, have been carried out. Contrary to previous reports, the reactions of 2,2'-bipyridyl with the halides (Mo₆C1₈)C1₄ and (Mo₆C1₈)I₄ yield, even under mild conditions, bipyridylium salts of chloromolybdic(II) and iodomolybdic(II) acids respectively: (BipyH)₂((Mo₆C1₈)X₆) where X = C1, I and Bipy = 2,2'-bipyridyl. The reactions are complicated by the formation of mixtures of products, which are mainly various crystalline forms of the bipyridylium salts. An amorphous product may be a true mono-bipyridyl complex. An unusual oxidation occurs during the reactions of triphenylphosphine (Ph₃P) and triphenylarsine (Ph₃As) with (Mo₆C1₈)C1₄ and (Mo₆C1₈)I₄. Infra-red spectral and X-ray powder photographic studies show that the oxidized ligand complexes, (Mo₆C1₈)x₄(Ph₃Z0)₂ (X = Cl, I; Z = As,P), are formed except under conditions in which both molecular and chemically-bound oxygen is rigorously excluded. The conditions required to coordinate more than two neutral unidentate ligands to the (Mo₆C1₈)⁴⁺ cluster have been examined. It proved possible to obtain new ionic complexes under a range of conditions. The six-fold coordination of the (Mo₆C1₈)⁴⁺ cluster is maintained in these compounds (e.g. ((Mo₆C1₈)I₃(triphenylphosphine oxide)₂(pyridine))⁺I⁻) by the ionization of one or more of the terminal halogen atoms in the molybdenum(II) halide starting material (e.g.(Mo₆C1₈)I₄). The X-ray single crystal structures of two isomorphous salts, (BipyH)₂(( (Mo₆C1₈)X₆) (X = C1,I), have been solved using the difference Patterson method. To solve another crystalline modification of the chloro-salt, the (Mo₆C1₈) cluster was constrained to its established geometry with its centroid fixed at the origin of the unit cell. This rigid group of atoms was then rotated by the least-squares refinement of the three orientation-defining angles. The three structures contain discrete ((Mo₆C1₈)X₆)²⁻(X = C1,I) and (C₁₀H₉N₂)⁺ (bipyridylium) ions. The anions consist of highly-symmetric (Mo₆C1₈) clusters (Mo-Mo = 2.606, Mo-C1 = 2.48 Ao), with six terminal halogen atoms (X) bound by single covalent bonds to the molybdenum atoms (Mo-Cl = 2.423, Mo-I = 2.737 Ao). The bipyridylium cations are twisted from perfect cis conformations in all three structures. The average dihedral angle between the two rings is 13 degrees. Further details of the geometries of the anion and cation are discussed. The ionic packing in the three crystals is dominated by the bulky anions. These are arranged in expanded "hexagonal close-packed" layers with the cations centred on approximately trigonal holes in this array. The two crystalline modifications of the chloro-salt differ in the orientation of the bipyridylium cations in these layers.

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  • Communities and interactions in nineteenth-century Scottish and English toxicology.

    Easton, Holly (2017)

    Masters thesis
    University of Canterbury Library

    The nineteenth century was a crucial period of development for toxicology in Britain, during which several great toxicologists rose to prominence. These toxicologists facilitated the creation of communities and intellectual networks of toxicology that operated throughout Scotland and England. Despite this crossover, previous scholarship has tended to focus on either Scotland or England, rather than both together. In assessing toxicology in both countries, this thesis aims to provide a new perspective on toxicology as it was used in criminal investigations. By tracking the development of toxicology over the nineteenth century in Scotland and England, this thesis examines how different aspects of toxicology were performed both within and across national borders. Despite the pressures exerted by the different national frameworks of law and education in each country, toxicology developed along a similar trajectory in each, a process that is examined using two toxicologists as focal points. Robert Christison and Alfred Swaine Taylor were the most eminent toxicologists in Scotland and England respectively, and through their positions of authority had enormous influence over the growing body of toxicology practitioners. This thesis uses them to examine the communities and intellectual networks that emerged within the body of toxicology practitioners, and changes in toxicological practice. This approach reveals the interdependency of expert toxicologists and ordinary practitioners across Britain. The writings of Christison, Taylor, and other toxicologists in medical journals and textbooks are the most important sources in this thesis, because they allow reconstruction of the situations and reactions of ordinary medical men, who made up the bulk of toxicology practitioners.

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  • The politics of privatizing water services : in theory and practice.

    Treliving, Victoria (2000)

    Masters thesis
    University of Canterbury Library

    Since the early 1980s, the phenomenon of privatization has quickly spread worldwide, changing the balance between the state and the market in favour of the latter. Its adoption questions and replaces the traditional roie of the state in providing and controlling certain public services. One formerly predominantly public service to be affected by privatization is piped water services, as it is commonly argued that private suppliers stimulate greater efficiencies and innovations than public suppliers. Most of those writing on this subject tend to focus narrowly on comparisons of public and private water companies in an attempt to argue that one or the other is best. Alternatively, some concentrate on the policy process through which privatization found favour. However, the thesis takes a very different approach to the analysis of privatizing water supplies, contributing to an area that has attracted little attention: its theoretical context and its implications for democratic politics. The aim of the thesis is to concentrate on, and extend, the types of assumptions - efficiency and innovation - inherent in arguments for privatization, thus providing a wide-ranging theoretical context in which to locate the privatization of water services. After discussing at some length exactly what comprises privatization, the thesis examines the theoretical foundations from which the policy originates. With reference to two case studies of privatization - Britain and Wales, which privatized water services in 1989, and New Zealand, which has not fully privatized its water, but is increasingly favouring more commercial practices - the thesis then illustrates how the theories have informed privatization in practice. The thesis concludes that privatizing water supplies . is an inappropriate extension of these theories because, first, they do not recognize the inherently non-commercial nature of water services and, second, because their implications for citizenship, and therefore democratic politics, are potentially very damaging.

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  • Readability and Quality of Web-based Information Related to Noise-Induced Hearing Impairment

    Johnson, Abigail (2017)

    Masters thesis
    University of Canterbury Library

    Aims: The purpose of this study was to assess the readability of online information pertaining to noise-induced hearing impairment (NIHI). This study aimed to answer several research questions: (1) What is the readability of online written information associated with searches related to NIHI? (2) Is the readability of online information significantly higher than the recommended 6th grade levels proposed by many researchers (Cheng & Dunn, 2015; Eloy et al., 2012; McInnes & Haglund, 2011; Misra, Kasabwala, Agarwal, Eloy, & Liu, 2012; Narwani, Nalamada, Lee, Kothari, & Lakhani, 2015; C. R. Patel, Sanghvi, Cherla, Baredes, & Eloy, 2015; Walsh & Volsko, 2008)? (3) Are there significant differences in the readability of NIHI-related online written material from different organisation origins (OOs)? (4) Are there significant differences in the readability of NIHI-related online material from different country origins (COs)? (5) Does webpage origin significantly interact with the presence of a Health On the Net (HON) certificate? Method: To answer the first four research questions, the researcher used five search terms derived from Google Trends that related to noise NIHI. These search terms were used to identify the first 10 relevant webpages associated with NIHI across 26 different English-language country coded top-level domains from Google. A total of 153 webpages were copied into Microsoft Word documents, which then underwent a readability analysis using Readability Studio (Oleander Software, 2012). To address the final research question, the researcher entered the root web address from each webpage into a HON search where the presence of a HON certification was determined. Results: The readability of the online information was significantly higher than recommended levels and the presence of a HON certificate was low. Webpages of a commercial origin were found to have significantly better readability than webpages of a governmental origin, across two out of the three readability measures used. There was no significant effect of CO on readability scores. The presence of a HON certificate was not significantly related to OO as per a chi-squared analysis; however, there was a significant interaction between the presence of a HON certificate and CO.

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  • Firing thyristors with negative firing angle using multilevel current reinjection concept: an experimental evaluation

    Das, B.P.; Watson, N.R.; Liu Y-H. (2016)

    Journal article
    University of Canterbury Library

    Thyristor based multilevel current reinjection (MLCR) current source converter (CSC) provides self-commutation capability to thyristors. It also has high quality line current waveform by accurately shaping the DC bus current using an auxiliary reinjection bridge. However the theoretical and PSCAD/ETDC simulation analysis do not take into account the inevitable stray capacitances and inductances which may influence the thyristor turnon/off and the simulation switching model may not represent the switching characteristics of the main bridge thyristors fully or accurately. Questions have been raised about the ability to achieve self-commutation with thyristors and the possibility of operating thyristors with negative firing angles. Therefore, it is necessary to experimentally verify whether neglecting the realworld artefacts actually impedes the performance of thyristor based MLCR CSC. The experimental results presented in this paper prove that the auxiliary reinjection circuit can force the thyristor to commutate independently from their respective line-to-line voltages and thyristor converter can operate with a negative firing angle.

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  • The Brooding Elitist Relationship-Wrecker: Tropes of Art and Artists on Narrative Television

    Joyce ZC (2017)

    Internet Publications
    University of Canterbury Library

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