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Research Commons is the University of Waikato's open access research repository, housing research publications and theses produced by the University's staff and students.
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Item The TOHU framework: Sensing and interpreting tohu to heal from trauma(Journal Article, Elsevier, 2024)This hypotheses article presents understandings and practices of tohu (signs) in the personal, eco-environmental, and spiritual wellbeing of Māori. Tohu can be observed in the natural, social, physical, or spiritual environment, and within a Māori worldview provide important ways of understanding and responding to phenomena. Wānanga (shared dialogue and debate) were held with seven Māori clinical psychologists from He Paiaka Tōtara (Māori Psychologist Network) and two mātauranga Māori specialists to explore their experiences, knowledge, and perspectives about tohu, with their insights collected through online information sharing. Our wānanga goals were to inform the creation of a therapeutic framework to address patu ngākau, psychological and spiritual trauma experienced by Māori. The results identified that tohu are located within the person and their environment, and the importance of exploring how tohu are interpreted. We propose a TOHU acronym as a framework for understanding and addressing the multifaceted impacts of patu ngākau.Item Characterisation and prediction of state of health of rechargeable batteries(Thesis, The University of Waikato, 2024)Electrochemical impedance spectroscopy (EIS) is used extensively in battery research, but usually at frequencies that do not reflect real-world usage patterns. This has resulted in equivalent circuit models (ECMs) that are over-complicated, and suboptimal battery management systems. It is logical to measure batteries at frequencies reflecting their daily or weekly charge-discharge cycles, i.e., of the order of microhertz. This is generally not done, however, because of difficulties that include extreme measurement durations and the need for care to avoid issues such as charge distribution problems, charge drift, and the risk of overcharging or flattening the battery. This research demonstrates the feasibility of extra-low frequency (ELF) EIS measurement using standard, non-specialised measurement equipment, and the optimisation of frequency domain data through the superimposition of small-signal measurement tones on larger square wave currents. Study of charge movement rates in the frequency domain and voltage responses in the time domain in batteries indicates connections between voltage sweep rate in cyclic voltammetry (CV) and current magnitude in incremental capacity analysis (ICA). The key factor determining what the investigator sees, e.g., reversibility of electrode processes or evidence of individual electrochemical reactions, is rate of movement of charge. Thus, controlled current can be used to obtain CV-type data from a battery, something that would be hazardous if done conventionally using a voltage ramp. Repeatable, low-error EIS measurements at ELFs are essential for inferring battery ECM components, including constant phase elements (CPEs). The fractional order of a CPE is linked to battery state of health (SoH) and energy efficiency. This thesis shows that efficiency measurements with waveforms representative of real battery usage can be used to track battery SoH accurately.Item Exploring approaches to support pacific student success in secondary schools(Thesis, The University of Waikato, 2024-01-01)The New Zealand education system has historically fallen short in addressing the needs of Pacific students, specifically at secondary school as they advance towards National Certificate of Educational Achievement (NCEA) levels. Efforts to improve the education of Pacific students have often focused on institutions making changes based on their own assumptions of what students need, without adequately involving students' own views. This thesis argues that attention should be directed towards the perspectives of Pacific students and how they can be motivated and encouraged to succeed in education. The study highlights the crucial role of teachers and how appropriate practices are used to develop their understanding of Pacific cultures to help these students thrive. The research aimed to uncover effective strategies employed by two secondary schools to promote Pacific students’ success. It explored Pacific students' views on their teachers' roles in their education and their interpretations of success in relation to their goals. Data collection was conducted through Talanoa sessions that embraced Teu le vā as an acknowledgement of mutual respect for each other’s space. Talanoa was carried out with Pacific students using two fa’afaletui, and with two Pacific liaison teachers using semi-structured interviews. Thematic analysis was used to organise the data and identify themes. Three key findings resulted from the study. Firstly, building on existing research demonstrated the integration of Pacific cultural values within the wider school curriculum. This approach supported and promoted effective relationships between teachers and Pacific students to achieve success as Pacific. Secondly, it highlighted that success for Pacific students was a collective endeavour that encompassed their cultural values, families, and broader Pacific communities. Thirdly, it pointed out that teachers deepened their understanding of Pacific cultural values through specific cultural frameworks. These frameworks included the Kāinga Tongan model, Tapasā, and the Pacific Values framework, that consequently improved knowledge and enhanced the engagement and academic success of Pacific students.Item Investigation into strain propagation to determine preserve regions for compliant mechanisms(Thesis, The University of Waikato, 2024)This thesis aims to improve the theoretical modelling of compliant mechanisms. The conclusions drawn from this work will help designers understand sources of error associated with strain propagation when designing with lumped compliance. Compliant mechanisms have increased in popularity as they allow for designs that feature lower part counts, increased precision and reduced manufacturing costs. Although using theoretical models to design compliant mechanisms is a useful tool, there is an assumption that only the nodes in a compliant mechanism undergo strain. This is not the case. There is strain occurring outside of the node in a region called the preserve region. The preserve region’s impact on the theory is greatly under-explored in the literature. The preserve region’s size, shape, and impact were found and quantified for a range of critical node types. This was done through the use of FEA software by altering the model of a simple, compliant mechanism. The size of the preserve region changed based on the thickness and the fillet used, with an increase of thickness from 4mm to 8mm, causing the radius of the arc that encompasses the preserve region to grow from 8.5mm to 13mm. The shape was also found to be an ellipse, irrespective of the node’s geometry. The preserve region’s impact on the theoretical models was also quantified. It was found that the thickness has the most drastic effect on the compliance values of the node, increasing the error from 20.53% to 102.18% when the thickness was increased from 4mm to 8mm. This work shows the importance of considering the preserve region when creating theoretical models of compliant mechanisms. When properly considered, this research shows that the error between the theoretical and the FEA values can be greatly reduced.Item How energetic constraints shape plant and soil invertebrate communities(Thesis, The University of Waikato, 2024)The Metabolic Theory of Ecology (MTE) and its predictions of the scaling of average population body mass with abundance and energy use are some of the most widely observed and studied biological relationships. However, the scaling exponent value of these relationships have been widely debated and found to vary considerably among various ecological communities and the ecosystems they occupy. Additionally, adherence to MTE predictions is widely contingent on its underlying assumptions and the variables used to describe these relationships. My thesis aims to provide a comprehensive analysis of the size–density and size–energy use scaling relationships of soil invertebrate and tree communities to shed light on the environmental and biological factors underpinning their observed exponents. To do this, I tested whether predictions of size–density scaling derived from MTE are dependent on ecosystem reassembly processes throughout succession and organism life history traits within trees and soil invertebrates. I also analysed size–density and size–energy use scaling in soil invertebrate food webs across four geographical locations to investigate the universality of size–density scaling relationships and their likelihood of accurately indicating energetic equivalence in soil communities of primary and secondary consumers. Additionally, I compared two measures of energy use to investigate size–energy use relationships: population metabolism and trophic energy fluxes in food webs. My findings suggested that size–density scaling, although related to energy use in ecological communities, is likely a poor indicator of energetic equivalence alone, but in combination with size–energy use scaling relationships can provide powerful insights into the energetic structuring of these communities. Additionally, size–density scaling exponents vary considerably across ecosystem succession and organism life form, and expectations should reflect these conditions. Energy flux as an estimate of energy use within communities for analysing size–energy use relationships was a more precise estimate compared to metabolism as it better captures the true energetic demands of organisms, particularly for secondary consumers which face stronger energetic constraints. Finally, analytically estimating energy fluxes with a trophic level–specific focus better captured the differences in patterns of energy use between these trophic levels compared to when they were pooled. Ultimately, this thesis provides new directions for exploring energetic equivalence in terrestrial communities.
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