Living Together

Aotearoa New Zealand is experiencing a crisis of socio-economic inequity rooted in a speculative housing market that transforms homes and territories into commodities. This transformation is underpinned by a powerful fiction: that private property and domestic space are natural, evolutionary outcomes of human development. Yet, as this thesis argues, such beliefs are neither neutral nor inevitable. They are the parts of historical processes that imposed ownership, enclosure, and hierarchy onto land and life

Investigation of soft suspension reaction wheel assembly spacecraft vibrations

Reaction wheel assemblies (RWAs) are the primary source of attitude control onboard spacecraft. The soft suspension RWA has an inherent design trade-off regarding the soft suspension’s stiffness that influences the impact dynamics and the loads that the RWA motor bearings may experience during launch. In orbital operation, these units often emit mechanical vibrations into the spacecraft’s structure, disturbing sensitive equipment. The advantage of incorporating a soft suspension system into a RWA is to reduce the quasi-static loads (QSLs) applied to the unit’s motor during launch, and to a lesser extent, to filter microvibrations in orbit. This thesis outlines the current state-of-the-art literature, component-level optimisation of soft suspension RWAs, and microvibration characterisation. It then considers the vibro-impact dynamics problem due to the chaotic launch environment. The primary goal is to predict the worst-case shock loads that sensitive components, such as motor ball bearings, may experience. Employing experimental paradigms and finite element models, a predictive mathematical model for a 2-Degree of Freedom (DoF) impact system is presented. The 1-DoF experimental setup validates a time-marching mathematical model which is extended to 2-DoF and subsequently validated using finite element analysis. The model is able to predict impact magnitudes that the RWA, especially sensitive components such as motor bearings, may experience during launch. Shocks occurring in the RWA during launch have the potential to damage the unit, causing additional unwanted disturbances, and offset the RWA applied torque axis with respect to the spacecraft’s axis resulting in attitude positioning errors subsequent to manoeuvres. This research develops a discrete model framework, with an experimentally derived coefficient of restitution, to predict bearing loads for an off-the-shelf motor employed in a soft suspension RWA providing the basis for a numerical design tool, to investigate optimal wheel-casing gap size to minimize contact shock magnitude and frequency. The parametric study demonstrated that an optimal gap size can be theoretically chosen to minimise the mean shock magnitude and frequency with respect to the system parameters and vibration input. The effective non-dimensionalisation of a complex power spectral density (PSD) by using a substitute uniform PSD with equal root mean square (RMS) allows broader theoretical consideration of various PSDs in the parametric study

Plasma-Induced Reactive Compatibilization of Polypropylene/Polyamide 6 Blends

The immiscible nature of most polymers causes challenges while formulating blends due to their interfacial tension and uncontrolled phase separation. Reactive compatibilization addresses this issue by introducing interconnecting groups, thereby reducing interfacial tension and stabilizing the morphology. This study investigated the use of a nonequilibrium atmospheric pressure air plasma jet (APPJ) during the extrusion process as a reactive compatibilization method for polypropylene (PP) and polyamide 6 (PA6) blends. As a proof of concept, we first evaluated the effect of plasma on the chemical structure and mechanical properties of PP and PA6. Attenuated total reflectance Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy analysis of the plasma-treated PP (pPP) revealed distinct peaks corresponding to hydroxyl and carbonyl stretching vibrations, confirming the presence of polar functional groups. Blends of PP/PA6 with 20/80, 50/50, and 80/20 weight ratios, with and without polypropylene grafted maleic anhydride (PP-g-MAH) as a compatibilizer, were compared to pretreated (PTIP) and in situ treated (PTB) blends. The PTIP blends demonstrated a significant increase in tensile strength and modulus compared with the untreated blends. Scanning electron microscopy of plasma-treated PP/PA6 blends revealed an excellent morphology akin to PP-g-MAH blends. Unlike PTB and untreated blends, the PTIP blends exhibited a continuous phase morphology. Compared to PTB blends, the plasma pretreatment in PTIP blends ensured comprehensive generation of reactive functional groups, resulting in significantly improved interfacial interactions and enhanced stress transfer during subsequent blending. FTIR spectroscopy at the Australian Synchrotron indicated that plasma-treated and PP-g-MAH compatibilized blends exhibited comparable molecular orientations at the interfaces. These findings demonstrate the effectiveness of plasma treatment in the reactive compatibilization of PP/PA6 blends, offering a sustainable method to enhance blend compatibility in polymer recycling processes

Unmanned Aerial Vehicle Propeller Noise

This paper gives an overview of work investigating the noise produced by the propellers used on small multi-rotor unmanned aerial vehicles (UAVs) which has been recently undertaken at the University of Auckland. There are a number of different physical mechanisms by which these propellers generate noise and these have been studied using computational and analytical modelling and experimental measurements. Sources of noise which are covered in this paper are: steady loading and thickness noise sources for isolated and shrouded propellers; unsteady blade motion; turbulent inflow for isolated and shrouded propellers; unsteady loading due to propeller-strut interaction; and the unsteady loading on the blades of a contra-rotating propeller. The paper also describes some recent work undertaken to develop a standardised method for measuring noise from UAVs which includes assessing the suitability of ground-board mounted microphones for outdoor noise measurements and identifying appropriate metrics for quantifying UAV noise. The paper concludes with suggestions for future work

Effectiveness of a Pharmacist-Led Intervention on Inappropriate Omeprazole Continuation Following ICU Discharge

Background: Omeprazole is frequently prescribed for stress ulcer prophylaxis (SUP) in critically ill patients. However, inappropriate continuation beyond intensive care unit (ICU) and hospital discharge is common, increasing the risk of adverse effects and healthcare expenditure. Although this issue is well documented in international studies no published research has evaluated targeted de-prescribing interventions in the New Zealand context. Aim: This study aimed to evaluate the effectiveness of a pharmacist-led intervention in reducing inappropriate omeprazole continuation among adult patients discharged from ICU. Primary objectives were to evaluate the prevalence of inappropriate omeprazole continuation at ICU discharge, hospital discharge, and six-months after discharge. The secondary objective was to calculate the direct medication cost savings. Methods: A retrospective, single-centre cohort study was conducted in three parts: (1) implementation of an ICU pharmacist-led intervention involving SUP education for staff, clinical pharmacist medication chart reviews, and an omeprazole indication documentation stamp; (2) retrospective data was collected before (Cohort 19, n=84) and after (Cohort 23, n=82) the intervention; and (3) calculation of direct medication cost savings. Cohort 19 comprised of eligible patients admitted between 1 March 2019 and 31 October 2019, whereas Cohort 23 included admissions from 23 March 2023 to 31 May 2023. Adults’ ≥18 years, who received at least, one dose of omeprazole during ICU admission were included. Patients with a pre-existing indication for acid suppression therapy, post cardiothoracic surgery, or pregnant were excluded. Results: SUP was initiated in over 90% of reviewed patients (Cohort 19 76/84, Cohort 23 80/82). Post- intervention; documentation of indication improved significantly from 17.9% to 76.8% (p<0.001), and discontinuation rates during ICU admission increased from 36.8% to 76.3% (p<0.001). Inappropriate continuation decreased significantly at ICU discharge from 50.7% to 7.1% (p<0.001), with similar improvements observed at hospital discharge (30.6% to 7.1%) and six-months post discharge. Direct medication cost savings totalled NZD $4,072.18 (excl GST). Conclusion: A structured, pharmacist-led intervention significantly reduced inappropriate omeprazole continuation across all transitions of care, enhancing medication safety, reducing polypharmacy, and achieving measurable cost savings. This model may inform national and local SUP deprescribing strategies in critical care settings

Selective Quantification of Charged and Neutral Polyfluoroalkyl Substances Using the Total Oxidizable Precursor (TOP) Assay

Perfluoroalkyl acid (PFAA) precursors are a diverse subclass of per- and polyfluoroalkyl substances (PFASs) that can be transformed into PFAAs of public health concern. Unlike strongly acidic PFAAs, precursors can be anionic, cationic, neutral, or zwitterionic. Precursor charge affects the environmental fate, but existing quantification techniques struggle to ascertain the abundance of compounds within each charge group. To fill this gap, we developed and validated a solid-phase extraction procedure that separates precursors by charge and quantifies the sum of the precursors in each fraction with the total oxidizable precursor (TOP) assay. Method performance was demonstrated by spiking known concentrations of ten precursors into aqueous film-forming foam (AFFF)-impacted groundwater, municipal wastewater, and soil samples. Precursor fractionation and recovery were greater in groundwater and soil samples than in wastewater. Use of the method provided results that were consistent with expectations based on precursor transport properties. In surficial soils near an AFFF source zone, anionic precursors with five or fewer perfluorinated carbons accounted for about 95% of PFASs, but less than half of PFASs in the underlying groundwater. In municipal wastewater influent, the sum of precursors exceeded the sum of PFAAs and was approximately equally distributed among all charge fractions

Co-erupted Plutonic Enclaves in Dacitic Magma at Belfond Volcano, Saint Lucia, from an Amphibole and Plagioclase Perspective

Amphibole and plagioclase phenocrysts in dacite with plutonic enclaves co-erupted at 13.6 ka from Belfond Volcano, Saint Lucia, provide insights into the dynamics of the magmatic system beneath the volcano. Three textural types of amphibole are present in the enclaves. Type 1 are normal zoned with a high-Mg core (11 – 15 wt%) and a thin, less magnesian rim. Type 2 are non-zoned, with little variation in MgO (~9 wt%). Type 3 have mafic cores with a patchy zoned texture consisting of low (12 – 13 wt%) and high (14 – 16 wt%) MgO zones. In contrast, all amphibole in the host dacite is cummingtonite. Three textural types of plagioclase are also identified in the enclaves. Type 1 are oscillatory zoned with a compositional range of An43 – 92. They generally lack a calcic core and most exhibit sieve texture in the outer mantle. Type 2 have a compositional range of An44 – 83, are oscillatory zoned and have a relic calcic interior (~An70) that has been resorbed and partly replaced by more sodic compositions (~An50). Type 3 have a compositional range of An45 – 94 and have a wide calcic interior (~An90) with diffuse or no zoning and a sodic rim (~An45 – 50). The dacite contains Type 1 and Type 2 plagioclase phenocrysts only. Equilibrium melt compositions determined from amphibole are mostly rhyolitic. The cores of the amphibole phenocrysts are consistent with nucleation in a less silicic melt, while rhyolitic melt compositions are estimated from outer-rim zones. Ca/Na ratios of plagioclase show that the sodic domains grew in a rhyolitic melt. In contrast, the calcic domains nucleated in a melt more calcic (and mafic) than the magmas erupted at Belfond. Melts modelled from Mg in plagioclase indicate that the phenocrysts re-equilibrated in a rhyolitic melt with a MgO content of ~0.2 – 0.5 wt%. This suggests that the phenocrysts were stored at elevated magmatic temperatures. Pressure and temperature conditions based on amphibole indicate two staging depths within the crust– a shallower system at ~5 km (~140 MPa) and temperature of ~800°C; and a deeper system at ~15 km depth (~400 MPa) and temperature of ~900°C. The shallower system correlates with more silicic melts as estimated from amphibole, while the deeper system correlates to more mafic melts. Phenocryst zoning patterns suggest that most amphibole and plagioclase phenocrysts nucleated in the mafic melt of the deeper system and later grew in the silicic melt in the shallower system. Cummingtonite originated in a hydrous and low-pressure zone of the magmatic system, indicating a separate magmatic evolution. This broadly aligns with previous models based on zircon chronology indicating prolonged storage. However, although the enclaves and dacite are co-magmatic, they evolved along distinct pathways

The Effects Of Different Earphone Types On Sound Localisation With And Without Music

Background: Sound localisation is essential for spatial awareness and safe environmental navigation. Impaired localisation can contribute to pedestrian injuries and fatalities, particularly in urban settings. One potential factor affecting localisation accuracy is the use of earphones. Therefore, this thesis examines how different earphone types and listening conditions influence localisation accuracy. Methods: Twenty normal hearing participants were recruited and seated at the centre of a room, surrounded by 12 loudspeakers positioned 1 meter away. Participants completed a localisation detection task, identifying the source of a car horn being presented in a randomised, counterbalanced order across the speakers. The localisation task was assessed in three conditions: (1) no earphones, (2) music played through earbuds, and (3) music played through open-ear earphones. Results: Results indicated increased localisation errors when participants used earphones, particularly for sounds originating from frontal speakers (speakers 12, 1, 2). However, no significant impairment was observed for sounds presented from rear-end speaker positions, suggesting that auditory cues from behind remained relatively unaffected. Additionally, no significant differences in localisation performance were found between earbuds and open-ear earphones. Conclusion: In summary, results indicated that earphones did introduce localisation errors, particularly at frontal sound origins, which may have implications for pedestrian safety, emergency alert system design, and intervention strategies. Future research should explore the impact of various earphone designs, the long-term effects of earphone use on spatial hearing, and the role of earphone-specific features in localisation performance

Investigating the mechanism of action of thioesterbased polymyxin B variants in different membranes using molecular dynamics simulations

Antimicrobial resistance poses a serious threat to global public health, and polymyxins remain one of the last-choice treatments for drug-resistant Gram-negative bacterial infections. The emergence of multidrug-resistant bacteria and the spread of resistance genes such as mcr-1 have further exacerbated this challenge. However, the dosedependent nephrotoxicity of polymyxins limits their clinical application, creating an urgent need for low-toxicity and effective polymyxin variants. This study employed all-atom molecular dynamics simulations to investigate the interactions between Polymyxin B3 and three thioester-containing polymyxin variants with polymyxin-sensitive and resistant inner and outer membranes of Eschericia coli. Specifically, we aimed to explore: (1) the mechanism of action of polymyxins; (2) the pEtN-mediated resistance mechanism; and (3) the differences in membrane interactions between thioester-containing polymyxin variants and Polymyxin B3. The results support that polymyxins act through the self-promoted uptake mechanism, progressing through three key stages: attraction, binding, and insertion. The positively charged L-2,4-diaminobutyric acid residues form strong electrostatic interactions with negatively charged phosphate groups on the membrane surface, followed by Mg²⁺ displacement, weakening of the hydrogen bond network, and ultimately, insertion of the hydrophobic tail into the membrane core, leading to membrane destabilization. pEtN modification reduces the net negative charge of lipid A, weakens the electrostatic attraction between polymyxins and the membrane, enhances lipid A crosslinking, increases membrane rigidity, and inhibits polymyxin binding and insertion. The thioester-containing polymyxin variants exhibited distinct membrane interaction properties. The CAD variant demonstrated the strongest binding affinity and membrane interactions, while the DMBA and BAS variants, due to their shorter hydrophobic tails, had reduced binding affinity and insertion capability. Overall, this study provides detailed insights into the mechanism of action and resistance of polymyxins, offering theoretical guidance for the design of novel polymyxin variants with improved efficacy and reduced toxicity, and contributing to antimicrobial resistance research

Kia Māori te Whakaako i te Tiriti o Waitangi: Connecting ākonga Māori to te Tiriti o Waitangi

This thesis generates new knowledge in relation to the research question: How can kaiako Māori (kaiako) support ākonga Māori (ākonga) to develop a greater understanding of, and connection to te Tiriti o Waitangi (te Tiriti) and the rangatira signatories? This qualitative study is grounded in Te Tai Tokerau perspectives and includes interviews with educators (n=4) who whakapapa to Te Tai Tokerau. The analysis is based on semi-structured in-depth interviews with three tumuaki (principals) and one kaiako (teacher), a core body of literature produced by Te Tai Tokerau scholars, a Kaupapa Māori theoretical paradigm, and Pūrākau methodology. Based on the research findings, three key discussion points are presented in relation to the importance of 1) developing relevant kaiako knowledge of te Tiriti, 2) utilising Māori language, culture, customs, principles and values in teaching te Tiriti, and 3) whakapapa, tino rangatiratanga and mana motuhake in connecting ākonga to te Tiriti and the rangatira signatories. This thesis culminates in the introduction of a new framework called Toitū te Tiriti i te Kura Framework, which was developed from the research findings. This framework is designed to support kaiako in teaching te Tiriti to ākonga from Te Tai Tokerau and is accompanied by a set of recommendations for its implementation. These findings reiterate the importance of whakapapa (genealogical connections) to Te Tai Tokerau and te ao Māori (Māori worldview) in teaching and understanding te Tiriti and the rangatira signatories