1,463 results for Thesis, 2011

  • Te Hiima : Reverend A. J. Seamer and his Māori mission

    Cervin, Georgia R (2011)

    Honours Dissertation thesis
    University of Otago

    Description: vi, 59 leaves : ill., ports. ; 30 cm. Notes: Cover title. "October 2011". University of Otago department: History. Thesis (B.A. (Hons.))--University of Otago, 2011. Includes bibliographical references.

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  • Cross-language phonetic priming in bilinguals.

    Sun, Keyi (2011)

    Masters thesis
    University of Canterbury Library

    This thesis looks at cross-language phonetic priming effects on late L1-dominant bilinguals, with different degrees of proficiency within the group. The participants in the study are 14 Chinese-English late bilinguals, whose production of vowels and consonants in different priming language contexts was analysed. The 14 speakers were divided into two groups based on their language proficiency. Information collected from questionnaires in two different languages was used to divide them into the two groups. They were required to participate in the experiment in two different sessions. On one occasion the interviewer spoke English to them and this was followed by their English reading and Chinese reading; whereas on the other occasion the interviewer spoke Chinese and the subjects did the opposite reading order from the first condition. Significant results of the analyses show that non-early, L1-dominant bilinguals do not differ in proficiency across priming conditions. Both groups show significant changes as the result of language priming for exactly the same vowels and the same consonants. Significant changes in the production of the sounds reveal interference between certain L2 sounds and their L1 counterparts. However, near significant results also show an unexpected direction of changes in production in L2, which may have been caused by experimenter identity. Furthermore, transfer effects of L1 on L2 found only among high proficiency speakers suggest that inhibitory control is dependent on L2 proficiency.

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  • Novel Organic Carbon Monoxide Releasing Molecules as a Potential Treatment for Triple Negative Breast Cancer

    Gunatunga, Kishan (2011)

    Undergraduate thesis
    University of Otago

    Carbon monoxide (CO) plays a role in many physiological and pathophysiological processes as a second messenger. Emerging evidence reveals the potential CO has as a therapeutic agent as it has been implicated in the modulation in a range of intracellular functions including apoptosis and proliferation. In the case of cancer, specifically triple negative breast cancer (TNBC), there is very little information regarding the effects of this molecule. Here we hypothesize that the targeted delivery of CO to a tumour will result in an anti-cancer effect in TNBC. The current study examines a novel class of compounds termed organic CO releasing molecules (CORMs) (CO-1 – CO-8) and previously published metal containing CORMs (CORM-2), as potential treatments for TNBC. Firstly a wide range of synthesised novel organic CORMs were screened for toxicity in MDA-MB-231 cells, a model for TNBC, and the lead compound CO-1 was identified from a range of 8 potential candidates (CO-1 – CO-8). Analysis of cell viability data revealed that CO-1 (1 – 200 μM) resulted in significant reductions in cell viability with an IC75 value of around 5 μM in the MDA-MB-231 TNBC cell line, while the by-product of CO-1, BP-1, demonstrated no residual cytotoxic effects. Time course and gas chromatograph-mass spectrometry (GC-MS) studies revealed that the compound released CO at a slow rate with a half-life in vitro between 9 and 24 hours. The ability of CO-1 and CORM-2 to modulate cell death via the induction of apoptosis was demonstrated using Annexin V conjugated to fluorescein (FITC) and propidium iodide (PI) staining followed by FACS analysis. CO-1 was able to induce apoptosis in MDA-MB-231 cells at both low (10 μM) and high (200 μM) concentrations (6% and 6% respectively) with no apoptotic or necrotic effects being observed when cells were treated with the by-product of CO-1, BP-1. The transition metal containing CORM-2 (200 μM) did not increase apoptotic markers compared to control, however treatment of cells with its “inactive” counterpart iCORM-2 (200 μM) resulted in a significant increase (7%) in apoptosis. In addition high (200 μM) but not low (5 and 10 μM) concentrations of CO-1 and CORM-2 produced a significant increase in the percentage of cells with a damaged mitochondrial membrane (3% and 5% for CO-1 and CORM-2 respectively), indicating that CO may have some concentration specific effects in vitro. High (200 μM) concentrations of both CO-1 and CORM-2 were also shown to induce mitochondrial damage in the MDA-MB-231 cell line and further to the potential anti-cancer effects of the novel compound CO-1, we have shown that low (10 μM) concentrations of the molecule causes a 1.2-fold and 1.4-fold increase in caspase 3 and p53 expression and a 1.2-fold increase in caspase 3 activation. The safety of both organic and transition metal CORMs were also assessed in the renal epithelial MDCK cell line. In MDCK cells treated with CO-1 (10 and 200 μM), COM-2 and iCORM-2 (20 and 100 μM) showed histopathological changes indicative of cell death were observed. These changes were not present in cells treated with the by-product of CO-1, BP-1. Interestingly the changes in histological architecture in MDCK cells treated with iCORM-2 appeared more extensive and severe that in cells treated with the active form of the compound CORM-2. Furthermore treatment of MDCK cells with low (10 μM) concentrations of CO-1, 20 and 200 μM CORM-2 and 200 μM iCORM-2 resulted in G2/M cell cycle arrest in the MDCK cell line. The current study proved CO-1, to be a safe and efficacious pharmacological agent with the ability to induce a cytotoxic and cytostatic effect in the MDA-MB-231 and MDCK cell line with no residual toxic effects resulting from treatment of cell with the by-product of CO-1 (BP-1). Our findings cast doubt over the notion that existing transition metal CORMs in their “inactive” form are not without biological effects. Therefore the current study has shown that novel organic CORMs have a combination of properties that translate into a desirable and potential treatment for TNBC.

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  • The development and applications of a micro-gap perforated electrode flow through cell

    Nath, Hilary (2011)

    Doctoral thesis
    University of Waikato

    Electrochemical techniques provide convenient and environmentally compatible ways of bringing about chemical transformations. However they generally lose their economic viability when used with low conducting electrolyte systems. This has limited their usefulness in the treatment of water and wastewater. Increasing the electrolyte concentration of these systems is not an option as it is with industrial processes such as the chlor-alkali process. Cell resistance is the major limiting factor. Cell resistance can be reduced by reducing the inter-electrode gap. A novel micro gap perforated electrode flow through (PEFT) cell has been developed for efficient and cost effective treatment of aqueous systems of low ionic strength. The PEFT cell is an undivided flow through design which encompasses both parallel plate and porous electrode features. It consists of plate electrodes and flow is both through the electrodes and parallel to the surfaces of the two electrodes. The perforations in the electrodes and the short flow distance between the electrodes allow the inter-electrode gap to be reduced to 50 microns and less without causing excessive resistance to hydraulic flow. With reduced electrical resistance, effective electrochemical treatment of natural water and other low electrolyte systems is possible. The PEFT cell was first applied to overcome a local water supply problem, the Waikato region’s iron and manganese contaminated bore waters. These waters form stable colloidal suspensions during slow air oxidation. The problem can be overcome by rapid electrochemical oxidation using the PEFT cell. Electrochemical oxidation was found to be more effective and efficient than chemical oxidation allowing removal of iron and manganese to meet drinking water standards with minimal formation of disinfection by-products (DBP). Electrochemical oxidation of water and wastewater systems is brought about principally by chlorine mediated indirect oxidation processes. A 240 µm gap PEFT cell, with a graphite anode was used for chlorine generation. It produced chlorine at current efficiencies above 60% with an energy consumption of 4.83 kWh/kg of chlorine from a 0.5 mol/L NaCl solution. This result compares well with industrial hypochlorite production using an undivided cell. Chlorine mediated electro-oxidation of effluents was successfully demonstrated by the degradation of textile dyes in water. Complete single pass electrochemical decolourisation of indigo carmine (IC) dye effluent containing 0.35 mol/L NaCl was achieved using a graphite anode PEFT cell. Energy consumption was 0.8 kWh/m3 or 8.3 kWh/kg of dye. This is an order of magnitude less than the energy consumption reported for colour removal using graphite anodes. It is comparable or lower than most colour removal work carried out using metal oxide coated dimensionally stable anodes (DSAs) and boron doped diamond (BDD) anodes. Reduction of pH from 7 to 3 reduced the energy consumption for decolourisation of IC dye by 50% and also increased the TOC removal by 20%. When NaSO4 was used as the electrolyte rather than sodium chloride, colour removal was much less effective. A single pass through a 50 µm gap PEFT cell with a stainless steel cathode and a graphite anode operated at 5.5 V achieved a 6 log inactivation of Escherichia coli bacteria in a water sample containing only 1.7 mmol/L of chloride ions. The power consumption was 0.5 kWh/m3 of water. The narrow inter-electrode gap allows high electric fields to be produced from low applied voltages. When the cell was operated at above 5.0 volts, a synergistic electric field effect was observed. Specific lethality of the chlorine was increased to at least 50 L/(mgmin), approximately two orders of magnitude higher than in the absence of the field. Increased specific lethality means that disinfection can be achieved at much lower free available chlorine levels than previously possible. This reduces the risk of DBP formation. Improved current efficiencies and reduced energy consumption for electrolysis at low electrolyte concentrations were achieved by partial insulation of the active anode surface of a 50 µm gap PEFT cell. This electro-catalytic effect was consistent with enhanced transport of the electroactive species to the active part of the electrode, reducing concentration and resistance overpotentials. In the electrochemical production of chlorine from 0.85 mmol/L NaCl at a current density of 2 mA/cm2, current efficiency was tripled and power consumption was reduced by a factor of two, relative to the cell without the anode modification. The reduction in the inter-electrode gap to 50 µm and less has allowed the production of electric field strengths greater than 10 kV/cm from applied voltages of less than a 100V. Field strengths between 1and 10 kV/cm are known to cause reversible electroporation whereas irreversible electroporation occurs above 10 kV/cm. Evidence for irreversible electroporation was provided by the 6 log inactivation of Escherichia coli (in the absence of chlorine) at an applied electric field of 22.5 kV/cm generated in a 40 µm gap PEFT cell by a 90 V DC supply. The energy consumption was 430 J/mL and without cooling, the temperature remained below 42oC. Inactivation was achieved by 20 hydrodynamically generated DC pulses. The low applied voltage, the elimination of the need for pulsed electric fields, avoidance of external cooling and the simplicity of the experiment bring commercial non thermal electro-pasteurisation one step closer.

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  • The black monk and the blue mystic : the writings and monochromatic paintings of Ad Reinhardt and Yves Klein

    Leiby, Bora Kim (2011)

    Other thesis
    University of Otago

    This dissertation is an examination of the monochromatic paintings and associated writings of Ad Reinhardt (1913-1967) and Yves Klein (1928-1962). Since its inception in 1918, the modern monochromatic painting has continued to fascinate, puzzle, and even upset viewers. Despite this, artists continue to explore this form. It would be unrealistic to assume that there is one artistic ideology that motivates all monochromatic painters. Trying to uncover all varying ideologies would be too difficult and require research based on the subjective writings of critics and historians. In an attempt to understand the monochrome from the artist's perspective I have analysed texts written by the artists regarding their own artwork. Not only did Reinhardt and Klein paint monochromatic images at the same time in history, but both documented their creative processes in writing. I have examined two edited collections of texts by these artists: Art-as-Art: The Selected Writings of Ad Reinhardt (1975) and the English translation of Overcoming the Problematics of Art: The Writings of Yves Klein (2007). The body of this dissertation uncovers similarities and differences in regards to formal aspects, functional roles, and sources of inspiration associated with these paintings. These include artistic rules regarding colour and line, the intended function of art in life, and a shared affinity for Eastern philosophy and aesthetics. While far from uncovering any universal monochromatic ideology, this examination provides some background on and appreciation for the creative process of monochromatic painting and a basic understanding of the reaction to the form.

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  • Investigating stratigraphic evidence for Antarctic glaciation in the greenhouse world of the Paleocene, eastern North Island, New Zealand

    Tayler, Michael James Stewart (2011)

    Masters thesis
    University of Waikato

    Early Paleogene (Paleocene-Eocene) climate was significantly warmer than today, with the poles generally considered to have been free of ice. These greenhouse conditions ended in the earliest Oligocene when the formation of the circum-Antarctic seaway between Antarctica and Australia had widened sufficiently to allow thermal isolation of the Antarctic continent and expansion of ice sheets to sea level. The associated invigorated Southern Ocean circulation patterns have been deemed responsible for formation of the Marshall Unconformity (32-29 Ma), a prominent hiatus in many Early Oligocene sedimentary sections in the wider New Zealand region. However, some recent studies have suggested there may have been short periods of significant Antarctic glaciation prior to opening of the circum-Antarctic seaway, including in the Late Paleocene at c. 58-57 Ma, referred to in this study as the “Late Paleocene event” (LPE). This study investigates the origin(s) of sedimentary sequences from four eastern North Island early Paleogene sections with the aim of determining whether any links can be made between the nature of the sediment facies and their bounding contacts with ice sheet growth on Antarctica. A late Paleogene section that records a possible occurrence of the Early Oligocene Marshall Unconformity has also been studied with the aim of comparing lithologic features from the site with those in the early Paleogene study sections. Methods used include detailed logging and description of sedimentary strata, and petrographic, mineralogical, grain size, elemental, stable carbon and oxygen isotope, organic carbon content, micropaleontologic, and palynofacies analyses. In the study sections the LPE is represented by dark grey, brown-grey, or black, occasionally glauconitic, non-calcareous mudstone, often with relatively high organic matter contents. Geochemical proxies indicate that during deposition of these lithologies siliceous microbiota were the dominant primary producers in the overlying surface ocean waters, suggesting a period of cooling and enhanced upwelling occurred at the time. Additionally, relative sea-level curves formulated for the studied sections through the Paleocene show three falls in sea level, the last of which coincides with the LPE. The relative sea-level curves are considered to represent eustatic changes in sea level and thus the fall that coincides with the LPE may record development of continental ice on Antarctica. The two interpreted falls in sea level prior to the LPE are also commonly associated with dominantly siliceous productivity and may record precursor cooling events. The occurrence of possible “dropstones” in Early to Late Paleocene strata at one section may also record fluctuations between glacial and interglacial conditions prior to, and possibly within, the LPE. There is presently inconclusive evidence for the Akitio River section recording the Early Oligocene Marshall Unconformity, but the glaucony bearing unit that has been suggested to mark the event is similar to some LPE lithofacies and is associated with an episode of increased biosiliceous productivity, supportive of climate cooling. Collectively these features suggest that the LPE may be associated with marked cooling and continental ice development on Antarctica, well before the circum-Antarctic seaway had widened sufficiently to allow thermal isolation of the Antarctic continent. This suggests that Antarctic ice sheet growth is less reliant on ocean heat transport than currently believed, and other mechanisms, such as draw down of atmospheric CO2, may also be involved. Other results from this study of less relevance to early Paleogene marine climate but of interest to general eastern North Island geology include the possible identification of Awhea Formation and Waipawa Formation at the Pahaoa coastal section in Wairarapa; interpretations of the depositional environments for the lithofacies in the study sections, involving dominantly hemipelagic upper to lower slope mudstone with occasional mass emplaced sandstone and pelagic limestone deposits; a suggested mechanism that led to organic matter enrichment in the Waipawa Formation; a possible explanation for the lateral transition of thick deposits of organic rich mudstone to relatively thin deposits of greensand and glauconitic mudstone; possible explanations for lateral variations in redox conditions; the possible correlation of an Early Eocene olistrostromic unit at Pahaoa with an olistrostomic unit farther south, suggestive of a major tectonic episode; and confirmation of an anomalous trend, noted by previous studies on several Paleocene-Eocene sections, within the Wanstead Formation of increasing terrigenous sediment input during a transgressive period.

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  • An investigation into environmentally responsible beverage packaging

    Herdering, Katrin (2011-05-04)

    Masters thesis
    Auckland University of Technology

    In this dissertation I construct and evaluate the business case for environmentally responsible beverage packaging as part of a sponsored project with both a theoretical and applied orientation. Theory on corporate sustainability and the win-win paradigm is investigated in the context of building a business case for environmental sustainability. My overall research question examines the likelihood that a win-win situation could be achieved in the most plausible business case for the introduction of an environmentally responsible beverage pack. Information for this project was derived through discussions with employees from six different departments at the sponsoring company and with 12 external current and potential value chain partners who may or may not be involved in any future introduction of a bioplastic beverage pack. Considerable background information was also researched as a basis for understanding the complexities of bioplastic beverage packaging and the assessment of a corporate environmental initiative. Regarding data analysis I took a reflective and pragmatic approach by assessing the above information against the background of my theoretical knowledge gained from relevant academic literature. I then decided on useful information to answer the research questions. I constructed the most plausible business case and assessed this case from an environmental and a financial perspective for further discussion with key stakeholders. Major findings include the multifaceted barriers opposing the introduction of an environmentally responsible beverage pack. These barriers threatening the realisation of a financial win encompass the high initial investment, compromised material properties, and the complexity of engaging value chain partners. The realisation of an environmental win is particularly threatened by the lack of management commitment to sustainability. I find that these factors make the establishment of a win-win situation particularly hard and are likely to result in trade-offs at the expense of sustainability. However, the difficulty in defining the impact of such a sustainability initiative on both environmental and financial performance hinders a precise assessment of whether a win-win situation could be established from the business case at present. I suggest that a major implication of my research for theory is the need for further development of metrics that support managers in holistically evaluating the financial impact of sustainability initiatives. Regarding recommendations to the sponsoring company, I acknowledge that at present, the business case for sustainability which I constructed in this project is unlikely to be strong enough to lead to the implementation of environmentally responsible beverage packaging. The practical value of my project is currently being assessed by the sponsoring company. At the very least, the research raised the sponsoring company´s executives’ awareness for necessary future steps if the company wanted to contribute to sustainable development.

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  • Exploring Operational Managers’ logic around trade-offs related to sustainability

    Daubenschuez, Tobias (2011-06-21)

    Masters thesis
    Auckland University of Technology

    This dissertation investigates how managers perceive trade-offs in relation to sustainability. The dissertation results from a research project with both a theoretical and applied orientation, following the argument that both in business and in theory, a “win-win paradigm” of sustainability prevails. According to the win-win paradigm, the extent of a company’s environmental and social commitment is principally restricted by its positive economic value. Drawing on a practical case, this dissertation contributes to this new and underexplored field of research around the win-win paradigm of sustainability. The dissertation 1) investigates the win-win paradigm with regard to the business case to be made for adoption of a particular initiative; and 2) explores operational managers’ logic around trade-offs related to sustainability. Academic and practitioner literature regarding sustainability, the win-win paradigm and sustainability-related trade-offs was reviewed, as was the context for business decisions. Data collection was based on in-depth interviews with operational managers from four different companies with an interest in a particular sustainability initiative. The data were analysed thematically and integrated with the afore-mentioned literature to inductively develop a series of hypotheses. The dissertation confirms that companies are trapped within the limits of the win-win paradigm of sustainability. Externally-oriented initiatives are regarded as more likely to overcome financial boundaries than are internally-oriented initiatives. It is found that the specifics of an industry determine the scope of the win-win zone for companies. The dissertation moreover argues that competitive forces reinforce the boundaries of the win-win paradigm and that the win-win zone is likely to expand in future in the particular initiative at the centre of this dissertation. Visible problems, which affect companies in exploiting their environmental and economic (win-win) opportunities, can be grounded in the hidden context of stakeholder-related trade-offs. These trade-offs stem from a lack of incentives for involved stakeholders. The recognition of these trade-offs is impeded by a lack of communication.

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  • Material properties and microstructures of Electron Beam welding similar and dissimilar titanium alloys

    Mitchell, Ryan James (2011-11-23)

    Masters thesis
    Auckland University of Technology

    Titanium is considered one of the best engineering materials for industrial applications with the different alloys offering a range of properties, which include low density, high fatigue life, corrosion resistance and high strength. Electron beam welding (EBW) is a high energy density welding process that occurs in an inert high vacuum environment. Welding of dissimilar metals or alloys offers the opportunity to take advantage of different material properties in different areas of a single part. The research aim of this master’s project was to identify the properties and microstructure of electron beam welding similar and dissimilar titanium alloys. Similar and dissimilar titanium alloy butt joint welds were created using an electron beam process. The welds consisted of commercially pure titanium (CP Ti), α+β alloy Ti6Al4V (Ti64) and β alloy Ti5Al5V5Mo3Cr (Ti5553). Microstructure was studied through the use of metallography and optical microscopy. Electron microprobe microanalysis (EPMA) was performed to identify the chemical composition across the welded samples. Mechanical testing was performed on welded samples to study the joint integrity and fracture characteristics. A scanning electron microscope investigation was performed on the fracture surface to reveal their fracture modes. Visually acceptable crack free electron beam welds were achieved for all similar and dissimilar combinations of titanium alloys. EPMA (electron microprobe microanalysis) scans showed that the dissimilar welds were well mixed with consistent composition across their fusion zones. Microhardness profiles of similarly welded CP Ti and Ti64 showed no significant change of the hardness in HAZ or fusion zones. Similarly welded Ti5553 alloy microhardness profiles showed softening in the HAZ and fusion zones. Dissimilar welds with Ti5553 showed a significant increase in hardness in the fusion zone. Most weldments exhibited mechanical properties comparable to the base metal, with negligible loss in ductility exhibited during tensile testing. Ti5553 to Ti64 and Ti5553 to Ti5553 weldments both failed prematurely below the tensile strength of both materials and exhibited very little elongation. Porosity was observed in the Ti5553 to Ti64 fusion zone. Early investigation using the Aramis system showed some confidence of significant elongation occurring in the fusion zones of similar and dissimilarly electron beam welded Ti5553.

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  • Effects of combined bronchodilators and oscillations on the the airway smooth muscle response

    Mathur, Meha (2011-07-22)

    Masters thesis
    Auckland University of Technology

    The current study aims to investigate the combined effects of oscillations and bronchodilators on the dynamics of the isolated contracted airway smooth muscle. Current day asthma treatments commonly use bronchodilators such as Isoproterenol to reduce the symptoms of asthma. Previous studies have shown the ability of length oscillations (such as those occurring during tidal breathing and deep inspirations) to have a bronchodilatory effect on normal activated airway smooth muscle both in vitro and in vivo. However, this effect is absent or transient in asthmatic airway smooth muscle. Although, many studies have been conducted to possibly understand the role of oscillations on the airway smooth muscle (ASM) dynamics, the exact mechanism is still unclear. Many studies have been conducted to look at the effects of length oscillations or perturbations on the contracted ASM dynamics, along with separate set of studies investigating the behaviour of ASM in the presence of bronchodilators. This study is novel in the sense that it experimentally investigates the effects of bronchodilators combined with length oscillations of varying parameters on the isolated airway smooth muscle. The experimental data suggest that the combined effect of the bronchodilator Isoproterenol and length oscillations is higher than that of each when applied alone. This response has been tested by varying the amplitudes and frequencies of the oscillations. The relaxation of the ASM subsequent to the application of oscillations was found to be proportional to the amplitude, but independent of the frequency of oscillations. This study gives more insight into the role of bronchodilators and oscillations (such as while breathing) on the contracted airways in an optimal goal of developing a new treatment methodology for asthma.

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  • Development of a novel humidifier for air breathing devices

    Brizio, Pablo Joaquin (2011-07-21)

    Masters thesis
    Auckland University of Technology

    Continuous positive pressure of air on the airways (CPAP) is the most common treatment for the obstructive sleep apnea syndrome. Humidification of the air applied to the patient improves patient compliance by preventing congestion and nasal and throat dryness. Most humidifiers used in CPAP systems are traditional heating-type humidifiers which consume large amount of energy. In this thesis, a non-traditional humidification technique was developed to be used in various respiratory supportive device applications such as CPAP therapy. Atomization processes were reviewed and ultrasonic atomizers were found to be the most suitable in terms of power consumption, droplets size distribution of the spray generated and size of the device. Four setups were used for experiments with these atomizers using five frequencies (1.5, 1.7, 2.1, 2.6 and 3.0 MHz). The experiments demonstrated that excitation with sine pulses has better efficiency than square pulses. In order to avoid overheating of the ultrasonic atomizer, the pulses must be sent in bursts and the frequency at which this bursts are sent (duty cycle) was proportional to the heating of the transducer. The droplet size distribution was measured by three different methods (photographic, impact and optic) and it did not have a significant change with the power applied to the transducer. The power did have a direct relationship with the atomization rate. Ultrasonic transducers with resonant frequency of 1.5 MHz are recommended for this application since the generated droplets have a small diameter (which facilitates its evaporation). The complexity of a driving circuit also increases with the frequency. Ideally there should be no water droplets in the air supplied to the patient. The evaporation of the droplets was mathematically modelled and experimentally tested to determine if the air that will be supplied needs to be heated to reach the fully evaporation. With an airflow rate of 60 L/min, the full evaporation of the droplets was reached in a relatively short distance (0.05 m) compared with the normal separation between the equipment and the patient (1.50m). There is no need to use a heater achieve such evaporation of the droplets. In this device, the pathogen risk could be reduced with the use of hydrophobic filters. This work demonstrates that ultrasonic transducers are capable of atomizing sufficient quantities of water for this application with low power consumption.

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  • Feasibility of using miniaturised electromagnetic actuator in small air pumps

    Wang, Lei (2011-06-21)

    Masters thesis
    Auckland University of Technology

    The feasibility of using an electromagnetic actuator as an important part in a portable diaphragm air pump is investigated. The ideal electromagnetic actuator will have capabilities of producing large deflection and high tuneable frequency. These two characteristics make the actuator very attractive for the present application. Much effort has been put into the development of the proposed diaphragm air pump because it is easily integrated into the complex system. The characteristics of the magnetic field of the electromagnetic coils are thoroughly investigated in order to complete the design optimization for the proposed electromagnetic actuator. As the base of the design optimization for the proposed planar and cylindrical coils, the proposed model of magnetic field distribution for a circular current loop is developed. The design optimization for various parameters of planar coils was thoroughly investigated. Approximate approaches to determine the electromagnetic forces are discussed. Models for diaphragm deflection were determined. The fluid model for evaluation of flow rate form the output of diaphragm pump was developed. The feasibility of using nozzle/diffuser elements as components of air pumps is investigated. The geometry of nozzle/diffuser elements was designed and the chamber configuration for the proposed electromagnetic air pump was determined. The proposed air pumps, including the electromagnetic actuator, PDMS (polydimethylsiloxane) diaphragm, and chamber and nozzle/diffuser elements were built. Several experiments were conducted to investigate the performances of the proposed electromagnetic actuator including the deflection of diaphragm and frequency characteristics. The flow rate of the proposed air pump was measured. In conclusion this study supplies solid evidence of achievements using electromagnetic actuators in air pumps.

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  • Thermomechanics, material flow and microstructure evolution during Friction Stir Processing of light cast alloys

    Cui, Song (2011-11-28)

    Doctoral thesis
    Auckland University of Technology

    Friction Stir Processing (FSP) is a solid-state processing technique which can be used to refine and modify as-cast microstructures for superior properties. The aim of the present research is to investigate the following fundamental aspects associated with FSP cast Al and Mg alloys: the quantitative relationships between processing speeds (rotation and linear speeds: ω and v) and the thermomechanical responses (tool torque–M, power–P, specific energy–Es and material flow volumes–Vflow); the details of material flow/deformation and microstructural evolution during FSP of a cast Al-Si alloy; the mechanism governing the removal of Beta-Mg17Al12 particles during FSP of cast Mg-Al alloys. Experimentally, FSP of A356 cast alloy were performed with wide ranges of ω and v. M was measured during each FSP experiment, and temperature (T) at various locations were monitored for selected experiments. Based on M, P and Es were calculated. Stir zone areas (Aflow) were measured using the metallographic samples to estimate Vflow values. FSP experiments, using tool-pin-breaking technique, were conducted on A356 plates under two representative conditions. Macro-scale flow, micro-scale deformation, and microstructural evolution were studied by means of Electron Backscatter Diffraction technique. Pin-breaking FSP experiments were also conducted on AZ91/AM60 cast alloys during which T was monitored, based on which the thermomechanical and metallurgical explanations for the removal of Beta-Mg17Al12 particles were investigated. The relationship between M and ω is found to be well described by an exponential decay function: M = Mo + Mfexp(–nω); while the influence of v on M can be described reasonably well by linearly relating Mo, Mf, and n to v. Together with the consideration of temperature data obtained, M is shown to intimately relate to material flow resistance to tool motion. Thus n and Mf can be adjusted for alloying effect in the low ω range, while such effect diminishes as ω increases. It is shown that tool shoulder flow volume generated per revolution (VS–rev = Ashouderv/ω) relates to M, which can be interpreted as energy input per revolution, in a form of M = Mo + Mf[1 – exp(–γVS–rev)]. The tool-pin flow volume does not require a proportional amount of energy input. The larger diameter of the shoulder compared to the pin, coupled with higher material flow stress near shoulder region are the fundamental causes of this. A new flow mechanism that explains the formation of the non-ring nugget during FSP A356 was identified. It is shown that regardless of the processing condition, the highly refined portion of the nugget zone clearly segregates from the less refined portion. How this macro-segregation relates to the difference in flow regime inside and outside thread spaces is demonstrated in detail. The deforming dendrites located ahead of the pin were traced and based on this the strain and strain rate during FSP were directly estimated. The mechanism governing the recrystallization of α-Al dendrites was identified primarily as Geometrical Dynamic Recrystallization. Recrystallized α-Al grains around the pin displayed a dominating “A” shear texture, although the local “A” texture must undergo a degree of rotation to obtain the ideal “A” texture due to the local texture frame misaligned with the ideal texture frame. It was found that this misalignment is closely related to the direction of material flow at the location under consideration. Finally, detailed evidences suggest that the major mechanism governing the removal of the eutectic beta-Mg17Al12 particles is through a sequence of incipient melting of beta-phase, Al rich liquid wetting recrystallized α-Mg grain boundaries thus leading to a significant increase in liquid/solid interface, transfer of Al solute from liquid to interiors of α-Mg and the growth of α-Mg into the liquid (resolidification).

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  • The impact of an infant sleep education programme on breastfeeding rates

    Newlands, Alana Marie (2011)

    Masters thesis
    University of Otago

    Concerns have been expressed that infant sleep education programmes which aim to promote good sleep habits in the first six months of life may have negative effects on breastfeeding because altering infant sleep may decrease breastfeeding opportunities. To date, the effect of an infant sleep education programme on breastfeeding exclusivity and duration, and maternal breastfeeding satisfaction has not been investigated. The objectives of the present study were to determine in a sample of Dunedin, New Zealand infants whether: an educational programme to prevent the development of infant sleep problems in the first six months postpartum was associated with differences in the duration of exclusive or “any” breastfeeding, or maternal breastfeeding satisfaction, when delivered without (objective 1) or with (objective 2) a lactation consultant. If there was an effect of the infant sleep education programme (without or with a lactation consultant) on breastfeeding outcomes, the secondary objective was to determine: the characteristics of the infant sleep education programme that may explain the potential differences in the duration of exclusive or “any” breastfeeding, or maternal breastfeeding satisfaction (objective 3). The present study was an observational longitudinal analysis following 150 infants from birth until six months of age, randomised to the Control (n=50), Sleep education (n=50) or Combination (sleep education and lactation consultant) (n=50) groups of the Prevention of Overweight in Infancy (POI) study. Sleep education was given antenatally, at three weeks postpartum, and was available upon request. Lactation consultant support was given antenatally, at one week and four months postpartum, and was available on request. Questionnaire data were collected monthly to determine the duration of exclusive or “any’ breastfeeding to the nearest week, breastfeeding patterns, and maternal breastfeeding satisfaction (measured by the Maternal Breastfeeding Evaluation Scale). A 24 hour infant sleep diary was administered at three, 19 and 26 weeks postpartum to collect infant sleep and breastfeeding duration and frequency data. Exclusive breastfeeding was defined as the infant having only received breast milk and prescribed medications from birth. “Any” breastfeeding was defined as the infant receiving at least some breast milk in the previous week. Cox proportional hazard regression was used to determine if the infant sleep education programme, delivered without (Sleep group) or with (Combination group) a lactation consultant, was associated with differences in the duration of exclusive or “any” breastfeeding up to six months postpartum. Multiple linear regression was conducted to determine if the infant sleep education programme, delivered without or with a lactation consultant, was associated with differences in maternal breastfeeding satisfaction. In this interim analysis of data from the POI study, p-values less than 0.014 were considered to indicate statistical significance. There was no evidence that the infant sleep education programme, delivered without (Sleep group) or with (Combination group) a lactation consultant, had a significant effect on the duration of exclusive (p=0.26) or “any” (p=0.87) breastfeeding, or on maternal breastfeeding satisfaction (p=0.20) compared to the Control group (objective 1 and 2). Because there was no evidence of an effect of the infant sleep education programme on breastfeeding duration, or maternal breastfeeding satisfaction, the characteristics of the sleep education programme explaining differences in these outcomes were not investigated (objective 3). This study did not find evidence that the infant sleep education programme was associated with differences in breastfeeding duration, or maternal breastfeeding satisfaction. However, due to the small sample size, there is considerable uncertainty surrounding the results of this present analysis and clinical or practical differences in breastfeeding outcomes between the study groups cannot be ruled out. Further analysis with a larger study sample is required to determine whether infant sleep education programmes influence the duration of exclusive or “any” breastfeeding, or maternal breastfeeding satisfaction.

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  • The effects of joint flight attendant and flight crew CRM training programmes on intergroup teamwork and communication

    Ford, Jane Rosemary (2011)

    Doctoral thesis
    University of Otago

    The aim of this research is to assess and evaluate the effectiveness of Crew Resource Management (CRM) training programmes for enhancing teamwork and cooperation between flight attendants and pilots. CRM programmes have been defined as the use of all available resources to achieve a safe flight (Helmreich, Merritt & Wilhelm, 1999). CRM programmes were developed for pilots following a series of accidents in the United States in the 1970s which were attributed to ineffective (or non-existent) communication within the flight decks. CRM programmes were extended to flight attendants in the 1990s after accident investigations had determined that some crashes could have been averted if flight attendants had passed on safety critical information to the pilots (e.g., the 1989 British Midlands crash at Kegworth). Human error is attributed to 60-80% of air accidents (Shappell and Wiegmann, 2004; von Thaden, 2008). Studies 1 and 2 involved a 36-item questionnaire for flight attendants which was administered before and after the introduction of the new CRM training programme for flight attendants at a South Pacific airline. The participating airline is a major air carrier so it was possible to obtain large samples (500+) for each of these quantitative studies. The results showed that there had been a significant attitude change in the positive direction. Multivariate analyses also revealed that there were significant differences between fleet type flown, crew position flown and length of service (seniority). As predicted crews with a greater length of service displayed safer attitudes as measured by the FSAQ (Flight Attendants) Crews on the narrow-bodied A320 and B737 showed safer attitudes than their colleagues on the wide-bodied long-haul aircraft. Flight attendants in senior positions (ISD, ISC, and Purser) also displayed safer attitudes. Study 3 followed up on the significant positive attitude changes through a series of seventeen focus groups which involved 100 flight attendants. The purpose was to obtain high quality qualitative data on perceived barriers (and solutions) to communication between pilots and flight attendants. The major barrier identified was the locked flight deck door which meant that flight attendants could not see periods of high workload on the flight deck and there was difficulty in communicating safety critical information over the interphone due to noise and the lack of face-to face contact. Flight attendants suggested that one possible solution would be to install CCVT cameras so that the pilots could see that it was safe to unlock the door or see the flight attendants face. Another barrier was seen to be the lack of a whole pre-flight briefing on long-haul aircraft as flight attendants rarely had the opportunity to even see the pilots on the large B747 aircraft. A solution would be to have the whole team assemble in the area nearest to the flight deck for a quick two-minute briefing. The full briefing would still be between the Captain and the lead flight attendant who would then brief the flight attendant team. These data were then used to develop Study 4 which consisted of a 14-item questionnaire (FSAQ-Pilots) which provided data on the ways pilots viewed the barriers (and solutions) to intergroup communication. The results from this study showed that pilots safety attitudes varied according to fleet type flown, length of service, and crew position flown. Captains, pilots on narrow-bodied aircraft and pilots with a greater length of service all displayed safer attitudes than their colleagues. The qualitative data displayed the same solutions to barriers as the flight attendants had shown. The major barrier was once more the locked flight deck door and the installation of CCTV cameras was recommended. A whole team pre-flight briefing was also recommended. Study 5 followed up on these data by developing a CD Rom which contained five scenarios presented in video clip format. These short video clips involved a landing gear malfunction, drunken passengers, a medical emergency and an explosive decompression followed by an emergency landing. All these provided opportunities for both pilots and flight attendants to identify how they would show intergroup communication and cooperative teamwork. Pilots and flight attendants identified very similar patterns of communication which showed effective intergroup teamwork. Pilots and flight attendants with seven or more years experience; those in leadership roles (Captains, lead flight attendants ); and crews on B737 , B767, and A320 fleets showed significantly lower perceived ratings of danger, volatility, complexity, the role of the captain,, flight attendants and communication in the majority of the five video clips (as described in Chapter 7). Study 6 was an experimental intervention based on the social identity and social categorization theories which formed the theoretical framework for this thesis. According to these theories flight attendants would be more willing to engage in cooperative teamwork behaviours when their social (as opposed to personal) identities had been primed. Three subscales were identified through factor analysis. The subscale labeled intergroup cooperation showed significant differences between the groups when social (as opposed to personal) had been primed. Flight attendants in the social priming condition indicated that they would be more willing to engage in intergroup teamwork. The results supported the main hypothesis. Social identity theory has not been applied to flight crew teamwork previously. These data showed that joint CRM training is valued by both flight attendants and pilots, especially when joint training sessions enabled both groups to meet and hence break down barriers to communication; a major aim of CRM programmes.

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  • Reframing perceptions of anthropomorphism in wildlife film and documentary

    Adcroft, Jane (2011)

    Masters thesis
    University of Otago

    The influence of anthropomorphism in wildlife film and documentary is often misconstrued and underestimated. Critics of anthropomorphic techniques simplify them as pandering to an audience’s cultural ideologies and expectations. Anthropomorphism, including personification, characterisation and narrative structure, are nevertheless inseparable from the wildlife filmmaking process. Inherently subjective, nature on screen is depicted as per the production and post-production choices of the wildlife filmmaker. Furthermore, film, as a medium for entertainment, has ensured that representations of animals reflect those that are popular and will provide entertaining viewing for a particular audience. This anthropomorphism has great importance and potential influence in increasing audience numbers and has the potential to inspire conservation action through greater awareness and science communication. Understandings of anthropomorphism need to move away from criticism of its validity as a filmmaking technique and be reframed towards its potential to inspire audiences.

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  • The fishery trend and feeding capacity of the New Zealand Littleneck Clam, Austrovenus stutchburyi, in a southern New Zealand inlet.

    Kainamu, Ani (2011)

    Masters thesis
    University of Otago

    Austrovenus stutchburyi is one of the dominant bivalves of New Zealand’s soft shore sheltered habitats (Morton and Miller, 1968; McArdle and Blackwell, 1989). The total inlet biomass level of A. stutchburyi has not differed since the initial survey within Papanui and Waitati Inlets; however, the size class biomass level has differed over time. Most important to the future of the fishery is the juvenile clam biomass that has depleted in both Inlets and remained low with no evidence to predict future recruitment. The laboratory study showed that the population factors of size class and density of clams affect the clam filtration rates of phytoplankton, with faster clearance rates by large sized clams at high density. The laboratory and field data were combined and showed that the total inlet filter capacity was 20.8 mg per day and 3.0 mg per day of chlorophyll a is filtered by medium and large clams respectively. This fishery that is harvested by non-commercial and commercial harvesters shows uncertainty in the pattern of recruitment of juvenile clams. The commercial operation needs to consider methods of restocking the population to restore the level of biomass in this fishery. This information provides a baseline assessment for monitoring the health of an inlet, and further monitoring of this dominant species should be continued to ensure the maintenance of its role in this system. Since this current study is based on the latest survey of 2004 and 2007 within Papanui and Waitati Inlet respectively, the improvement in management and the restoration of this population is urgent.

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  • Shared spaces in New Zealand urban areas

    Shearer, David (2011)

    Masters thesis
    University of Otago

    The concept of shared spaces is gaining popularity around the world as an innovative approach to streetscape design. Shared spaces are streets which have very little separation between road users; meaning pedestrians, cyclists, and vehicles literally share the road space. Traffic control infrastructure is often removed from shared spaces to introduce a degree of uncertainty to urban streets, necessitating a more careful and courteous style of driving with the aim of increasing safety for all road users. Shared spaces are beginning to appear in New Zealand cities. This thesis provides a context of this introduction of shared spaces into New Zealand’s urban areas and the issues that may affect the success of shared space in New Zealand. This includes examining what shared spaces currently exist and how well they are functioning, as well as any proposed shared spaces. Local authorities were contacted to evaluate the position of local government with regard to the shared space concept. Also, the purported advantages and disadvantages of shared spaces are investigated in a New Zealand-specific context to gauge the appropriateness of the concept for the country. It was found that well designed shared spaces could enhance New Zealand’s urban areas by balancing the needs of all road users and creating more pedestrian friendly public spaces. However, more research needs to be undertaken to investigate the effect that shared spaces will have in New Zealand, and also to find ways to aid blind and visually impaired people in navigating the spaces. Three types of shared space have been suggested and case studies have been used to apply these suggestions in public spaces in Dunedin and Oamaru.

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  • The influence of exotic salmonids on native host-parasite dynamics

    Paterson, Rachel Anne (2011)

    Doctoral thesis
    University of Otago

    Native parasite acquisition provides introduced species with the potential to modify native host-parasite dynamics by acting as parasite reservoirs (with the ‘spillback’ of infection increasing the parasite burdens of native hosts) or sinks (with the ‘dilution’ of infection decreasing the parasite burdens of native hosts) of infection. Exotic salmonids are frequently shown to acquire native parasites; however, as research into the threats posed by exotic salmonids has largely focused on predation and competition, threats posed by shared native parasites are poorly understood. I used a multiple-pronged approach combining field observations, experimental infections and dynamic population modelling to investigate whether native parasite acquisition by exotic salmonids alters host-parasite dynamics in native fish populations from streams and lakes in New Zealand and Argentina. I also used a meta-analysis approach to investigate which trait(s) influence native parasite acquisition by exotic freshwater fish. My research demonstrated that two key factors strongly influence whether the dynamics of native parasites will be affected by exotic fish. On one hand, the competency of exotic fish for native parasites is an important determinant of whether native parasite populations are likely to increase or decrease. On the other hand, the relative abundance of the exotic species determines whether its competency for a native parasite will actually translate into altered native host-parasite dynamics, with highly abundant exotic species more likely to induce changes in native parasite dynamics. I also demonstrated how exotic species may be able to override the influence of low host abundance, or competency by altering native host behaviour. The meta-analysis suggested that traits known to influence parasite richness in native fish or invasion success of exotic species are not reliable predictors of native parasite acquisition by exotic fish. Instead, it is more likely that complex interactions between a variety of biological, geographical and historical factors govern parasite acquisition by exotic species, making it difficult to predict whether native parasites will be acquired.

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  • The Pursuit of Happiness

    Reid, Katherine Anne (2011)

    Masters thesis
    University of Otago

    Is the frequent monitoring of happiness in daily life actually detrimental to happiness? Current psychological literature suggests that explicit focus on happiness may actually be self-defeating (Schooler, Ariely, & Lowestein, 2003). The current thesis investigated the psychological effects of frequent self-monitoring of happiness outside the laboratory in daily life. A total of 223 young adults (92 men) from the University of Otago were randomly assigned to one of four experimental groups. Commercially available SMS text message software was used to send participants either one, three or six text messages per day for 13 days inquiring about their current level of happiness. A fourth control group also received six text messages per day inquiring about non-mood related experiences. Findings showed no differences in changes in momentary or trait happiness between the three experimental groups, suggesting no reactivity as a result of monitoring happiness overall. Conversely, group differences in changes in momentary happiness were moderated by personality variables self-esteem and dysphoria. Findings suggested that increased monitoring of happiness among those with low self-esteem and high dysphoria leads to a decrease in happiness over time. Interestingly, there was also some evidence that frequent reporting of non-emotional states led to a decrease in trait happiness among those low in self-esteem. Taken together, these findings suggest that the heightened focus on happiness throughout western society today may actually be detrimental to the happiness of those with greater vulnerability to lower mood – i.e. those with low self-esteem or high dysphoria.

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