90,549 results

  • Gold-based Nanomaterials: Spectroscopy, Microscopy and Applications in Catalysis and Sensing

    Adnan, Rohul (2015)

    Doctoral thesis
    University of Canterbury Library

    The birth of nanotechnology era has revolutionized materials science, catalysis and field of optoelectronics. Novel and unique phenomena emerge when material dimensions are reduced to ultra-small size regime and enter nanometre (2-100 nm) realm. Such novel materials are expected to replace bulk materials, offering lower cost of manufacturing and enabling progress in many areas such as solar cell, drug delivery, quantum communication and computing, catalysis and sensing applications. With the progress in nanomaterial synthesis and fabrication, the need for the state-of-art characterization techniques became obvious; such techniques help to establish a complete understanding of the nature and interactions of nanosized materials. In this thesis, the first part focuses on the synthesis of gold and ruthenium clusters, namely Au8, Au9, Au101, Ru3, Ru4 and AuRu3, using the well-established synthetic protocols in the literature. Apart from the standard lab-based characterization techniques such as nuclear magnetic resonance (NMR), UV-visible spectroscopy (UV-vis) and Fourier Transform Infra-red (FTIR), a less explored but useful technique far infra-red (far IR) spectroscopy, available at the Australian Synchrotron (AS), was employed to investigate the vibrational modes in these clusters. Peaks in the experimental far IR spectra were assigned unambiguously to specific vibrations by comparing with the ones generated via DFT calculations with the help of collaborators, group of Professor Gregory Metha, University of Adelaide. For the Au9 cluster, three significant gold core vibrations are observed at 157, 177 and 197 cm-1 in the experimental spectrum. In the case of the Ru3 cluster, only a single ruthenium core vibration is identified within the spectrum, at 150 cm-1 with the calculated force constant, k = 0.33 mdyne/Å. The Ru4 cluster exhibits two metal core vibrations at 153 and 170 cm-1 with force constants of 0.35 and 0.53 mdyne/Å, respectively. Substitution with a gold atom yielding a mixed metal AuRu3 cluster shifts the core transitions toward higher wavenumbers at 177 and 299 cm-1 with an increase in force constants to 0.37 and 1.65 mdyne/Å, respectively. This is attributed to the change in chemical composition and geometry of the metal cluster core. A combination of the DFT calculations and high quality synchrotron-based experimental measurements allowed the full assignment of the key transitions in these clusters. Next, these clusters were fabricated into heterogeneous catalysts by depositing on different metal oxide nanopowders. Synchrotron X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) studies were performed at the Australian Synchrotron and the Photon Factory synchrotron in Japan to investigate the electronic structure of Au8, Au9 and Au101 on TiO2 catalysts. The XPS analysis reveals that “as-deposited” Au8 and Au9 retain some un-aggregated clusters while Au101 show bulk-like gold. These findings are in line with TEM observations, where the aggregates (large particles, > 2 nm) of Au8, Au9 and Au101 are hardly seen under HRTEM. UV-visible diffuse reflectance spectroscopy (UV-vis DRS) studies show the absence of localised surface plasmon resonance (LSPR) peaks in these “as-deposited” clusters, suggesting they are below 2 nm in size. Importantly, the XAS spectrum of “as-deposited” Au9 clusters estimates that 60% of pure, un-aggregated Au9 clusters and 40% of bulk gold in the sample. Upon calcination under O2 and combined O2 and H2 (O2-H2), Au8, Au9 and Au101 clusters form larger nanoparticles (> 2 nm) with the appearance of LSPE peak in UV-vis DR spectra. In addition, majority of the phosphine ligands (that stabilise the gold core) dislodge and form phosphine oxide-like species by interacting with oxygen on the TiO2 surface. The third part focused on testing the catalytic performance of the supported Au8, Au9, Au101, Ru3, Ru4 and AuRu3 clusters on different TiO2, SiO2, ZnO and ZrO2 in benzyl alcohol oxidation. Au101-based catalysts display the highest catalytic activity with a turn-over frequency (TOF) up to 0.69 s-1. The high catalytic activity is attributed to the formation of large Au nanoparticles (> 2 nm) that coincides with the partial removal of capping ligands. Au8 and Au9 clusters which contain NO3- counter anions are found to be inactive in benzyl alcohol oxidation. Further work shows that the presence of NO3- species diminishes the catalytic activity. Monometallic ruthenium clusters, Ru3 and Ru4, are found to be inactive yet the bimetallic AuRu3 clusters are active in benzyl alcohol oxidation, suggesting the synergistic effect between ruthenium and gold metal. Investigation of catalytic testing parameters reveals that tuning selectivity of the product is possible through manipulating the reaction temperature. Finally, a joint experiment with Prof. Wojtek Wlodarski’s group at RMIT, Melbourne was undertaken to test the sensing ability of Au9 clusters for hydrogen detection. Au9 clusters were deposited onto radio-frequency (RF) sputtered WO3 films at two different concentrations; 0.01(S1) and 0.1(S2) mg/mL. It was found that the optimal temperatures for sensor S1 and S2 were 300 °C and 350 °C, respectively. The sensor with lower Au9 concentration (S1) displays a faster response and recovery time, and a higher sensitivity toward H2. HRTEM studies reveal that the sensor S1 contain a significant population of sub-5 nm Au nanoparticles which might be responsible for a faster rate of H2 adsorption and dissociation. The key finding in this study suggest that the addition of catalytic layer such as ultra-small Au9 clusters results in improved sensitivity and dynamic performance (response and recovery time) of H2 sensors. In summary, this thesis demonstrated that cluster-based nanomaterials have wide range of applications spanning from catalysis to sensing. Further improvements in material synthesis and use of multiple complimentary characterization techniques allowed better understanding of the nature of the key active species (metal nanoparticles) assisting design of catalysts and sensors with enhanced performance.

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  • Managing Non-Traditional Security Concerns in the Context of Competing Maritime Claims: A Path to Peace or a Road to Nowhere

    Scott, K. N. (2014)


    University of Canterbury Library

    The South China Sea (SCS), which extends over 3.5 million kilometres with an average depth of 2000 metres1 has become synonymous with intractable territorial and maritime delimitation disputes with the disagreement over the Spratly Archipelago (involving six nations - China, Taiwan, Vietnam, Malaysia, Brunei, Philippines) and the Paracel Archipelago (3 nations – Vietnam, China and Taiwan) being the most high profile of the disputes. What I would like to do in this paper, as part of this project, is to explore the extent to which a focus on non-traditional security concerns actually represents a viable pathway either to the resolution of the territorial and maritime delimitation disputes between the competing claimants or to the development of a long term interim solution whereby a framework is developed allowing states to manage the region without resolving those disputes.

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  • Small business tax compliance burden : what can be done to level the playing field.

    Ma, David (2015)

    Masters thesis
    University of Canterbury Library

    One of the major issues associated with taxation are the costs incurred by taxpayers when they comply with their tax obligations, this is particularly important for smaller business taxpayers. Compliance costs are found to be regressive, falling with disproportionate severity on smaller businesses. This trend can be found across the globe and more importantly, in New Zealand. Prior research has shown that the severity of the regressiveness has increased over time. The current, “one-size-fits-all”, approach used in the New Zealand tax system, and others alike, have created undue complexity for small businesses. This study reviews small business tax regimes and concessions currently implemented (or proposed) in different countries to relieve the compliance burden for smaller businesses. Australia, South Africa, the United Kingdom and the United States have either implemented a separate tax regime, or offers tax concessions to smaller business taxpayers. New Zealand on the other hand, presents minor ad hoc tax concessions for small business taxpayers, but since 2009, there have been proposals to change this system. This study evaluates and compares all the implemented (or proposed) regimes and concessions of the selected countries. Following from the case studies, interviews are conducted with tax professionals that have worked closely with smaller businesses, in order to shed light on the possibility of implementing a similar regime in New Zealand. The findings show that a small business tax regime has many avenues to consider, however, there is general consensus that suggests small business taxation should be kept as simple as possible. This thesis puts forward a baseline for further discussion and development of a small business regime to reduce compliance costs for smaller businesses.

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  • Investigation and Prediction of the Sound Transmission Loss of Plywood Constructions

    Wareing, Robin Richard (2015)

    Doctoral thesis
    University of Canterbury Library

    The sound transmission loss of a range of plywood panels was measured to investigate the influence of the orthotropic stiffness of the plywood panels. The plywood panels were tested as single and also double leaf partitions, with a range of stud configurations. A new method was developed for predicting the sound transmission loss of single leaf partitions with both orthotropic and frequency dependent stiffness values. The sound transmission loss was evaluated for two significantly different sample sizes. The observed influence of the sample size on the measured sound transmission loss was profound. The construction of the partition was shown to significantly affect the influence of the sample size on the sound transmission loss. A qualitative analysis based on existing published research of the contributing factors is presented, and methods for adjusting the results for the small sample size for comparison with the large results were developed. The influence of a range of acoustic treatments of lightweight plywood partitions was investigated. The treatments involved internal viscoelastic materials and decoupled mass loaded barriers in various arrangements. The attachment between the treatment and the plywood panel was found to influence the sound transmission loss significantly. A prediction method based on published models was modified to allow the influence of the treatments to be included. Reasonable agreement was achieved between the predicted and measured results for a wide range of samples. A prediction method was developed that accounts for the influence of orthotropic, frequency dependent material parameters. This method utilised an adaptive, numerical integration method to solve an analytical formulation for the sound transmission loss. The influence of the finite sample size was accounted for using an expression for the finite panel radiation impedance. The finite panel radiation impedance was predicted analytically and an approximation was also presented. The presence of a significant source room niche was accounted for by applying an appropriate limit to the integration range of the angle of incidence. The prediction methods developed are compared with the measured transmission loss results from both the small and large test facilities. Good agreement was seen for some of the predicted results. Generally the agreement within the coincidence region was worse than for the rest of the transmission loss curve. The inclusion of orthotropic and frequency dependent stiffness values significantly improved the agreement within the coincidence region.

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  • A Capabilities Solution to Enhancement Inequality

    Swindells, Fox (2014)

    Masters thesis
    University of Canterbury Library

    Human enhancements will dramatically alter individuals' capabilities and lead to serious harm if unregulated. However, it is unclear how states should act to mitigate this harm. I argue that the capabilities approach provides a useful metric to determine what action states should take regarding each enhancement technology. According to the capabilities approach, states are responsible for ensuring their citizens are able to function in certain ways that are essential to human life. I consider the impact of a range of enhancements on individuals' capabilities in order to determine what actions states should take regarding each technology. I find that in order to be just and prevent harmful inequality, states will need to ensure many enhancements are available to their citizens. I also explore a range of other regulations aimed at harm prevention. Considering the impact of enhancement technologies on human capabilities, and the appropriate regulatory options for states, under the guide of the capabilities approach allows me to demonstrate that the capabilities approach can provide valuable, realistic, advice to guide public policy in response to enhancement technologies.

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  • Refinement and Normalisation of the University of Canterbury Auditory-Visual Matrix Sentence Test

    McClelland, Amber (2015)

    Masters thesis
    University of Canterbury Library

    Developed by O'Beirne and Trounson (Trounson, 2012), the UC Auditory-Visual Matrix Sentence Test (UCAMST) is an auditory-visual speech test in NZ English where sentences are assembled from 50 words arranged into 5 columns (name, verb, quantity, adjective, object). Generation of sentence materials involved cutting and re-assembling 100 naturally spoken ‟original” sentences to create a large repertoire of 100,000 unique ‟synthesised” sentences. The process of synthesising sentences from video fragments resulted in occasional artifactual image jerks (‟judders”)‒quantified by an unusually large change in the ‟pixel difference value” of consecutive frames‒at the edited transitions between video fragments. To preserve the naturalness of materials, Study 1 aimed to select transitions with the least ‟noticeable” judders. Normal-hearing participants (n = 18) assigned a 10-point noticeability rating score to 100 sentences comprising unedited ‟no judder” sentences (n = 28), and ‟synthesised” sentences (n = 72) that varied in the severity (i.e. pixel difference value), number, and position of judders. The judders were found to be significantly noticeable compared to no judder controls, and based on mean rating score, 2,494 sentences with ‟minimal noticeable judder” were included in the auditory-visual UCAMST. Follow-on work should establish equivalent lists using these sentences. The average pixel difference value was found to be a significant predictor of rating score, therefore may be used as a guide in future development of auditory-visual speech tests assembled from video fragments. The aim of Study 2 was to normalise the auditory-alone UCAMST to make each audio fragment equally intelligible in noise. In Part I, individuals with normal hearing (n = 17) assessed 400 sentences containing each file fragment presented at four different SNRs (-18.5, -15, -11.5, and -8 dB) in both constant speech-shaped noise (n = 9) and six-talker babble (n = 8). An intelligibility function was fitted to word-specific data, and the midpoint (Lmid, intelligibility at 50%) of each function was adjusted to equal the mean pre-normalisation midpoint across fragments. In Part II, 30 lists of 20 sentences were generated with relatively homogeneous frequency of matrix word use. The predicted parameters in constant noise (Lmid = 14.0 dB SNR; slope = 13.9%/dB ± 0.0%/dB) are comparable with published equivalents. The babble noise condition was, conversely, less sensitive (Lmid = 14.9 dB SNR; slope = 10.3%/dB ± 0.1%/dB), possibly due to a smaller sample size (n = 8). Overall, this research constituted an important first step in establishing the UCAMST as a reliable measure of speech recognition; follow-on work will validate the normalisation procedure carried out in this project.

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  • “You Want To Capture Something that Will Make People Change”: Rhetorical Persuasion in The Cove, Whale Wars, and Sharkwater.

    Stewart, Jessica (2014)

    Masters thesis
    University of Canterbury Library

    Dolphins, whales, and sharks are some of the world’s most iconic animals. Yet, many people will only ever see these animals via the media. The media, then, hold significant power in creating, modifying, or reaffirming the imaginaries around various species which, in turn, influences how much concern is given to matters related to their welfare and conservation. Given the environmental and ecological concerns presently facing the ocean, protecting, conserving, and preserving the marine ecosystem is vital, and time is of the essence. Through the work of activists, three specific marine wildlife issues have received a lot of publicity across various forms of mainstream media: the killing of dolphins in Taiji, Japan for their meat; Antarctic whaling; and the practice of shark-finning. Three activist films, namely The Cove (2009), Whale Wars (2008-), and Sharkwater (2006), are centred on these issues, and filmmakers attempt to compel viewers to support the activists’ protectionist cause. In order for this goal to have a chance of coming to fruition, rhetorical arguments must be carefully crafted. Yet, the study of rhetoric in animal-focused activist films is still an understudied research area. This thesis contributes to this area of research by using the aforementioned films as case studies by applying Aristotle’s rhetorical proofs of ethos, pathos, and logos to analyse the rhetorical arguments. Ethos is demonstrable when the activists construct themselves as credible, moral heroes and the animals as possessors of positive traits worth protecting, and the hunters as immoral villains. The graphic imagery of animal death appeals to pathos to stir strong bodily and emotional responses such as sadness, and disgust in order to mobilize audience support for cause. Lastly, these films appeal to logos through the use of culturally authoritative discourses such as those of biology, western conventional medicine, and the legal system. This thesis essentially argues that these texts work rhetorically and discursively to persuade audiences to feel a connection with and sympathy towards the animals; to be supportive of the activists; and to prompt antipathy towards the hunters and industry spokespeople.

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  • The temperature dependence of the far-infrared-radio correlation in the Herschel-ATLAS

    Smith, D.J.B.; Jarvis, M.J.; Hardcastle, M.J.; Vaccari, M.; Bourne, N.; Dunne, L.; Ibar, E.; Maddox, N.; Prescott, M.; Vlahakis, C.; Eales, S.; Maddox, S.J.; Smith, M.W.L.; Valiante, E.; de Zotti, G. (2014)

    Journal Articles
    University of Canterbury Library

    We use 10,387 galaxies from the Herschel Astrophysical TeraHertz Large Area Survey (HATLAS) to probe the far-infrared radio correlation (FIRC) of star forming galaxies as a function of redshift, wavelength, and effective dust temperature. All of the sources in our 250 μmselected sample have spectroscopic redshifts, as well as 1.4GHz flux density estimates measured from the Faint Images of the Radio Sky at Twenty centimetres (FIRST) survey. This enables us to study not only individual sources, but also the average properties of the 250 μm selected population using median stacking techniques. We find that individual sources detected at 5 in both the H-ATLAS and FIRST data have logarithmic flux ratios (i.e. FIRC q parameters) consistent with previous studies of the FIRC. In contrast, the stacked values show larger q , suggesting excess far-IR flux density/luminosity in 250 μm selected sources above what has been seen in previous analyses. In addition, we find evidence that 250 μm sources with warm dust SEDs have a larger 1.4GHz luminosity than the cooler sources in our sample. Though we find no evidence for redshift evolution of the monochromatic FIRC, our analysis reveals significant temperature dependence. Whilst the FIRC is reasonably constant with temperature at 100 μm, we find increasing inverse correlation with temperature as we probe longer PACS and SPIRE wavelengths. These results may have important implications for the use of monochromatic dust luminosity as a star formation rate indicator in star-forming galaxies, and in the future, for using radio data to determine galaxy star formation rates.

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  • World Internet Project Trends in NZ

    Smith, P

    Conference item
    Auckland University of Technology

    No abstract.

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  • Carving a niche for minority language media studies not so easy. Book Review of ‘Social Media and Minority Languages: Convergence and the Creative Industries’, edited by E. Gruffydd Jones and E Uribe-Jongbloed

    Smith, P

    Journal article
    Auckland University of Technology

    Whenever a new field of research emerges a lot of shuffling and sorting of knowledge is required to establish a niche, to define its boundaries, to encourage acknowledgement of the area and to stimulate debate concerning the application of various methodologies and theoretical frameworks. This is the case with Social Media and Minority Languages: Convergence and the Creative Industries. The catalyst for the book’s production, as implied by the title, is the technological advancement of social media, the resulting convergence of media in the digital age, and perhaps most importantly the positive and negative effects these have on minority or minoritised languages. Yet in reviewing its 17 chapters by more than 30 authors, it is clear the overall objective appears to be strongly focused on the reinforcement of Minority Language Media (MLM) as a field of study distinct from mainstream media studies because of its specific concern with ‘how media can be used to help languages’ (p. 255).

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  • An evaluation of seasonal variations in footwear worn by adults with inflammatory arthritis: a cross-sectional observational study using a web-based survey

    Brenton-Rule, A; Hendry, GJ; Barr, G; Rome, K

    Journal article
    Auckland University of Technology

    Background: Foot problems are common in adults with inflammatory arthritis and therapeutic footwear can be effective in managing arthritic foot problems. Accessing appropriate footwear has been identified as a major barrier, resulting in poor adherence to treatment plans involving footwear. Indeed, previous New Zealand based studies found that many people with rheumatoid arthritis and gout wore inappropriate footwear. However, these studies were conducted in a single teaching hospital during the New Zealand summer therefore the findings may not be representative of footwear styles worn elsewhere in New Zealand, or reflect the potential influence of seasonal climate changes. The aim of the study was to evaluate seasonal variations in footwear habits of people with inflammatory arthritic conditions in New Zealand. Methods: A cross-sectional study design using a web-based survey. The survey questions were designed to elicit demographic and clinical information, features of importance when choosing footwear and seasonal footwear habits, including questions related to the provision of therapeutic footwear/orthoses and footwear experiences. Results: One-hundred and ninety-seven participants responded who were predominantly women of European descent, aged between 46–65 years old, from the North Island of New Zealand. The majority of participants identified with having either rheumatoid arthritis (35%) and/or osteoarthritis (57%) and 68% reported established disease (>5 years duration). 18% of participants had been issued with therapeutic footwear. Walking and athletic shoes were the most frequently reported footwear type worn regardless of the time of year. In the summer, 42% reported wearing sandals most often. Comfort, fit and support were reported most frequently as the footwear features of greatest importance. Many participants reported difficulties with footwear (63%), getting hot feet in the summer (63%) and the need for a sandal which could accommodate a supportive insole (73%). Conclusions: Athletic and walking shoes were the most popular style of footwear reported regardless of seasonal variation. During the summer season people with inflammatory arthritis may wear sandals more frequently in order to accommodate disease-related foot deformity. Healthcare professionals and researchers should consider seasonal variation when recommending appropriate footwear, or conducting footwear studies in people with inflammatory arthritis, to reduce non-adherence to prescribed footwear.

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  • Therapeutic Approaches in the Attenuation of Seizure-Induced Cardiomyopathy

    Andreianova, Anastasia Alexeevna (2015)

    Masters thesis
    University of Otago

    Single subcutaneous administration of Kainic acid (KA) in the rat produces significant levels of seizure activity, including head tremors, salivation and tonic-clonic convulsions. Using electrophysiological quantitative techniques which measure electroencephalographic (EEG) as well as electrocardiographic (ECG) trace activity following KA administration, the effects of seizure activity on the function of the heart were assessed over a 48 hour period. In addition, histopathological analysis was carried out in order to determine whether the ongoing seizure activity produced significant changes in ventricular myocardium indicative of irreversible cardiomyopathy. In order to determine the potential mechanism of action of KA-induced cardiac damage, a further two animal groups were examined. The groups consisted of animals pretreated with either atenolol or clonidine. The two different drugs were used in order to isolate systems involved in cardiac damage, where atenolol acts specifically in the periphery, while clonidine is known to act in the central nervous system. Analysis of EEG and concomitant ECG traces, during and following seizure activity demonstrated significant changes in heart rate (HR) as well as associated HR parameters compared to baseline. Upon further histological observations it was apparent that at 48 hours following KA administration, ischaemia was present as well as evidence of inflammatory cell infiltration, tissue tearing and oedema compared to saline treated animals. Further assessment of pretreated animal groups lead to the conclusion that atenolol was not protective against KA-induced cardiac damage in the rat while clonidine was. These findings propose that the mechanism by which KA-induced seizure activity results in cardiomyopathy is through modulation of brain centres associated with cardiac control, as opposed to KA binding to peripheral cardiac receptors as previously suggested.

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  • GREEN Grid Choice Modelling preliminary report

    Williams, John Richard (2014)

    Conference item
    University of Otago

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  • El camino se hace caminando: Using Participatory Action Research to evaluate and develop Peace Education practice in a Secondary School in Northern Nicaragua

    Kertyzia, Heather (2015)

    Doctoral thesis
    University of Otago

    Peace education (PE) is included in the cross-curricular themes of the Nicaraguan curriculum, yet in the Secondary School in Northern Nicaragua (SSINN) where this research was conducted there was varied implementation by teachers. The SSINN was selected for this research due to particular problems with violence. Based on a critical and post-development theory perspective and using participatory action research (PAR) methodology, teachers, school psychologists and administrators were led through a facilitated process of reflection upon the culture of peace/violence in the SSINN and teacher practice. This was guided by the concepts of education about (content), for (skills and behaviours) and by peace (pedagogy). PAR is guided by a series of principles that allow for flexibility and response to participant needs. In this case SSINN educators and I engaged in a process of building trust, gathering reconnaissance data, developing action plans and taking action. This was guided by our unofficial motto ‘the path is made by walking’ (el camino se hace caminando), implying that we were learning as we worked together and the process had to be adaptable to new circumstances. Through workshops and coffee chats we evaluated staff definitions of a culture of peace, priorities in relation to peace values, behaviours and content, and teacher practice in regards to peace principles. As part of the reciprocal process, educators gave feedback and directed the research, which was designed to emphasize educator voice and minimize the neo-colonial imposition of values from outside actors. In this way I sought to balance critical theory’s need to take action for positive change with post-development theory’s prioritizing of local educator voice. The primary goals of the research were to develop an understanding of how PE was practised in the SSINN and, if the educators requested it, to provide support in taking positive action for change, while assessing the effectiveness of the PAR methodology. In the beginning the educators had differing definitions of a culture of peace, but they were very consistent in their ideas of what content, skills and values should be included in PE. Although they regularly mentioned problems that were directly relevant to students’ lives that should be addressed in the classroom, not all of the teachers were actively doing this. Due to a lack of resources, time, teacher stress and overcrowding, many teachers were unable to translate those ideas into action. Also due to those factors, many teachers fell into habits of traditional teaching practice that were inconsistent with peace pedagogy. Recognizing these issues, the teachers requested workshops on non-violent communication and conflict transformation in the hope that that knowledge would aid them to more positively manage behaviour. They also created and implemented an action plan. Although positive steps were taken, this was the first stage of a long-term process of change. Partnering with local non-governmental organizations (NGOs) has provided the possibility of the continuation of the process; nevertheless those NGOs have stated that they need continued external support. This flexible PAR methodology was effective at exploring and developing PE practice in the SSINN, and has the potential, if continued, to lead to fundamental positive change.

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  • A multi-modal device for application in microsleep detection

    Knopp, Simon James (2015)

    Doctoral thesis
    University of Canterbury Library

    Microsleeps and other lapses of responsiveness can have severe, or even fatal, consequences for people who must maintain high levels of attention on monotonous tasks for long periods of time, e.g., commercial vehicle drivers, pilots, and air-traffic controllers. This thesis describes a head-mounted system which is the first prototype in the process of creating a system that can detect (and possibly predict) these lapses in real time. The system consists of a wearable device which captures multiple physiological signals from the wearer and an extensible software framework for imple- menting signal processing algorithms. Proof-of-concept algorithms are implemented and used to demonstrate that the system can detect simulated microsleeps in real time. The device has three sensing modalities in order to get a better estimate of the user's cognitive state than by any one alone. Firstly, it has 16 channels of EEG (8 currently in use) captured by 24-bit ADCs sampling at 250 Hz. The EEG is acquired by custom-built dry electrodes consisting of spring-loaded, gold-plated pins. Secondly, the device has a miniature video camera mounted below one eye, providing 320 x 240 px greyscale video of the eye at 60 fps. The camera module includes infrared illumination so that it can operate in the dark. Thirdly, the device has a six-axis IMU to measure the orientation and movement of the head. These sensors are connected to a Gumstix computer-on-module which transmits the captured data to a remote computer via Wi-Fi. The device has a battery life of about 7.4 h. In addition to this hardware, software to receive and analyse data from the head-mounted device was developed. The software is built around a signal processing pipeline that has been designed to encapsulate a wide variety of signal processing algorithms; feature extractors calculate salient properties of the input data and a classifier fuses these features to determine the user's cognitive state. A plug-in system is provided which allows users to write their own signal processing algorithms and to experiment with different combinations of feature extractors and classifiers. Because of this flexible modular design, the system could also be used for applications other than lapse detection‒any application which monitors EEG, eye video, and head movement can be implemented by writing appropriate signal processing plug-ins, e.g., augmented cognition or passive BCIs. The software also provides the ability to configure the device's hardware, to save data to disk, and to monitor the system in real time. Plug-ins can be implemented in C++ or Python. A series of validation tests were carried out to confirm that the system operates as intended. Most of the measured parameters were within the expected ranges: EEG amplifier noise = 0.14 μVRMS input-referred, EEG pass band = DC to 47 Hz, camera focus = 2.4 lp/mm at 40 mm, and total latency < 100 ms. Some parameters were worse than expected but still sufficient for effective operation: EEG amplifier CMRR ≥ 82 dB, EEG cross-talk = -17.4 dB, and IMU sampling rate = 10 Hz. The contact impedance of the dry electrodes, measured to be several hundred kilohms, was too high to obtain clean EEG. Three small-scale experiments were done to test the performance of the device in operation on people. The first two demonstrated that the pupil localization algorithm produces PERCLOS values close to those from a manually-rated gold standard and is robust to changes in ambient light levels, iris colour, and the presence of glasses. The final experiment demonstrated that the system is capable of capturing all three physiological signals, transmitting them to the remote computer in real time, extracting features from each signal, and classifying simulated microsleeps from the extracted features. However, this test was successful only when using conventional wet EEG electrodes instead of the dry electrodes built into the device; it will be necessary to find replacement dry electrodes for the device to be useful. The device and associated software form a platform which other researchers can use to develop algorithms for lapse detection. This platform provides data capture hardware and abstracts away the low-level software details so that other researchers are free to focus solely on developing signal processing techniques. In this way, we hope to enable progress towards a practical real-time, real-world lapse detection system.

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  • Descriptions of coping with commonly occurring events by highly self-regulated boys living in earthquake-affected Christchurch

    Gillman, Solfrid Hessellund (2015)

    Masters thesis
    University of Canterbury Library

    Children are often overlooked in the aftermath of a natural disaster, and children’s use of coping strategies plays an important part in their post-disaster adaptation (Vernberg, La Greca, Silverman, & Prinstein, 1996). The aim of this qualitative study was to explore the coping strategies of children with adequate self-regulation skills and minimal behaviour problems, living in Christchurch following the major 2010 and 2011 earthquakes. This aim was achieved through the use of semi-structured interviews with five seven-year-old children, their parents, and their teachers. These interviews were analysed using Directed Content Analysis and results showed that children most often reported using active and adaptive coping strategies, followed by avoidant strategies. Results in the current literature regarding children’s coping suggest that children exposed to natural disasters are able to utilise strategies that involve some personal control over their environment and emotions, through the use of active and adaptive coping strategies. Findings from this study contribute to the current understanding of children’s use of coping strategies when faced with commonly occurring childhood upsets. Further research is required regarding the outcomes associated with the use of effective coping strategies following traumatic events.

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  • Geochemical variations in glauconitic minerals : application as a potassium fertiliser resource.

    Smaill, Joshua Ballantyne (2015)

    Masters thesis
    University of Canterbury Library

    Nutrients for plant growth are often limited in soil systems and additions are required in the form of fertiliser. Potassium is an essential macro-nutrient for plants and demands for K are expected to increase in the future. Glaucony is an abundant marine mineral which may provide an alternative K-rich fertiliser resource. The South Island of New Zealand contains deposits of glaucony-rich rocks which were deposited in the Early- to Mid-Cenozoic during periods of low sedimentation to the seafloor. Here, the geochemistry of glaucony from the Waitaki Basin (Otago), the Waipara Greensand (North Canterbury) and the Stoney Creek Limestone (Karamea) was examined using spatially resolved geochemical analysis and dissolution experiments. Grain-by-grain analysis using Laser Ablation Induction Coupled Plasma Mass Spectrscopy (LA-ICP-MS) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM + EDS) revealed that glaucony from all deposits were of the mature type and were enriched in K. Glaucony derived from growth inside faecal pellets was found to contain elevated K and Fe concentrations compared to bioclast hosted glaucony. These variations can be explained by the physical properties of host grains and sea-floor redox conditions at the time of precipitation, both of which increased ionic mobility into the zone of glauconitisation. Solubility analysis showed that K^{+} was released from glaucony more rapidly than any other element. Additionally, decreasing the pH and introducing an oxidising agent (i.e, birnessite which is ubiquitous in soil environments) accelerated K^{+} release 13-fold. Trace metals including Cr, Zn, Cu and Ni were present in the solid phase analysis, however further investigation revealed that these elements were released into solution in low concentrations and may present a source of micro-nutrients, not a soil contaminant. These results suggest that glaucony may offer a source of slow releasing K fertiliser, and the South Island of New Zealand is ideally situated as a place to consider using glaucony as a locally sourced, environmentally sustainable K resource for agriculture.

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  • How (Not?) to Adapt Chekhov: Adventures in Dramaturgy

    Ridley, Nathaniel (2014)

    Masters thesis
    Victoria University of Wellington

    Despite rapid growth of adaptation theory in the last two decades, there is a gap in the field. Books like Linda Hutcheon’s A Theory of Adaptation (2006) and Julie Sanders’ Adaptation and Appropriation (2006) approach adaptations from an audience’s perspective, describing the effects of the adaptation process and providing a robust taxonomy, identifying all of different forms that adaptation might take. They do not, however, describe the details of the process of adaptation itself, even though they often refer to the need for a process-oriented account of adaptation. Existing adaptation manuals focus on screen-writing, leaving someone with an interest in the specifics of adapting a play nowhere to turn. This paper begins to address this gap in the available knowledge by documenting the adaptation process involved in the creation of four new adaptations of Anton Chekhov's Uncle Vanya, targeted at a New Zealand audience. The experiments presented here confirm what is suggested by a survey of the reception of English-language adaptations of Chekhov: there is no single correct method for adapting a play. An adapter's greatest challenge can be identifying which strategy is appropriate for the conditions they face. This project experiments with different adaptive methods and strategies, developed by looking at other English-language Chekhov adaptations, including techniques of approximating the setting, language and themes to a target audience. I attempt to identify which methodologies will achieve the desired results, revealing a variety of different challenges, advantages and weaknesses inherent to each approach. Moreover, both the research and the experiments suggest how the success or failure of an adaptation depends on a variety of contextual factors, including the target audience's relationship with the adapted work, the dramaturgical characteristics of that work, and the abilities of the adapter.

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  • Electronic Conduction in Disordered Carbon Materials

    Cheah, Chun Yee (2015)

    Doctoral thesis
    Victoria University of Wellington

    Graphene, consisting of a single layer of carbon atoms, is being widely studied for its interesting fundamental physics and potential applications. The presence and extent of disorder play important roles in determining the electronic conduction mechanism of a conducting material. This thesis presents work on data analysis and modelling of electronic transport mechanisms in disordered carbon materials such as graphene. Based on experimental data of conductance of partially disordered graphene as measured by Gómez-Navarro et al., we propose a model of variable-range hopping (VRH) – defined as quantum tunnelling of charge carriers between localized states – consisting of a crossover from the two-dimensional (2D) electric field-assisted, temperature-driven (Pollak-Riess) VRH to 2D electric field-driven (Skhlovskii) VRH. The novelty of our model is that the temperature-dependent and field-dependent regimes of VRH are unified by a smooth crossover where the slopes of the curves equal at a given temperature. We then derive an analytical expression which allows exact numerical calculation of the crossover fields or voltages. We further extend our crossover model to apply to disordered carbon materials of dimensionalities other than two, namely to the 3D self-assembled carbon networks by Govor et al. and quasi-1D highly-doped conducting polymers by Wang et al. Thus we illustrate the wide applicability of our crossover model to disordered carbon materials of various dimensionalities. We further predict, in analogy to the work of Pollak and Riess, a temperature-assisted, field-driven VRH which aims to extend the field-driven expression of Shklovskii to cases wherein the temperatures are increased. We discover that such an expression gives a good fit to the data until certain limits wherein the temperatures are too high or the applied field too low. In such cases the electronic transport mechanism crosses over to Mott VRH, as expected and analogous to our crossover model described in the previous paragraph. The second part of this thesis details a systematic data analysis and modelling of experimental data of conductance of single-wall carbon nanotube (SWNT) networks prepared by several different chemical-vapour deposition (CVD) methods by Ansaldo et al. and Lima et al. Based on our analysis, we identify and categorize the SWNT networks based on their electronic conduction mechanisms, using various theoretical models which are temperature-dependent and field-dependent. The electronic transport mechanisms of the SWNT networks can be classed into either VRH in one- and two-dimensions or fluctuation-assisted tunnelling (FAT, i.e. interrupted metallic conduction), some with additional resistance from scattering by lattice vibrations. Most notably, for a selected network, we find further evidence for our novel VRH crossover model previously described. We further correlate the electronic transport mechanisms with the morphology of each network based on scanning electron microscopy (SEM) images. We find that SWNT networks which consist of very dense tubes show conduction behaviour consistent with the FAT model, in that they retain a finite and significant fraction of room-temperature conductance as temperatures tend toward absolute zero. On the other hand, SWNT networks which are relatively sparser show conduction behaviour consistent with the VRH model, in that conductance tends to zero as temperatures tend toward absolute zero. We complete our analysis by estimating the average hopping distance for SWNT networks exhibiting VRH conduction, and estimate an indication of the strength of barrier energies and quantum tunnelling for SWNT networks exhibiting FAT conduction.

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  • Protection Against Slavery in New Zealand

    Heesterman, Katja (2014)

    Scholarly text
    Victoria University of Wellington

    The European Court of Human Rights decision in CN v The United Kingdom highlighted that slavery remains a modern problem. It may no longer resemble the traditional picture of slavery dramatically presented by Hollywood but it is no less on an issue. Modern slavery is less visible; it is hidden away within homes, normal workplaces or in overseas factories. This paper argues that New Zealand’s current treatment of slavery is inadequate exemplified by the absence of prosecutions. Thorough protection of slavery requires clear definitions that courts can easily apply. This paper explores how the Bill of Rights could be used to remedy this situation. This paper argues for the application of the Drittwirkung concept to give a horizontal effect to a right against slavery. Furthermore it is argued that New Zealand is under positive obligations to actively prevent rights violations, not merely avoid them. These positive obligations are a key component of modern human rights jurisprudence and can be read into the New Zealand Bill of Rights Act 1990. This paper speculates that one action courts could take is to undertake the development of a tort action against slavery.

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