13,067 results for Doctoral

  • Nutrition and Reproductive Condition of Wild and Cultured New Zealand Scallops (Pecten novaezelandiae)

    Wong, Ka Lai Clara

    Doctoral thesis
    Auckland University of Technology

    The New Zealand native scallop, Pecten novaezelandiae, is a species with a high economic value as a wild catch and has good potential for cultivation. As a mean to enhance the future of this growing shellfish industry, this thesis set out to investigate the nutritional requirements of P. novaezelandiae in relation to reproductive conditions, and determined the physical and biological factors that affect the condition of this scallop species in the wild and cultivated environments. Adult scallops (Pecten novaezelandiae) were sampled from six populations in the Hauraki Gulf (Auckland, New Zealand) in the spawning season (October 2014), in order to evaluate the scallop reproductive condition and nutritional state across the populations. Results showed a spatial variation in reproduction condition (VGI and gonad index), with a higher number of mature scallops in populations closer to the shoreline, where higher food availability may be found. Conversely, nutrient content in scallop somatic tissues (adductor muscle carbohydrates and digestive gland lipids) did not vary across the populations, but was strongly associated with reproductive status of individual scallops (VGI). Nutrient (carbohydrates, proteins and lipids) storage and utilization were investigated within scallops from two sites in the Hauraki Gulf, bi-monthly over a year (2012−2013). In addition, sediment samples were also taken to evaluate the potential for re-suspended nutrients as a food source for scallops. Water samples were collected for seston and chlorophyll a analyses. Isotope analyses (carbon and nitrogen) and proximate analyses were conducted for the gonad, adductor muscle and digestive gland of wild P. novaezelandiae, sediment samples and the seston (1.2−5μm, >5μm). Isotope analyses revealed distinctly different signatures in suspended sediment and scallop tissues, indicating that re-suspended nutrients were unlikely to contribute to the diet of scallops. Nevertheless, seston (particularly the small fractions) signatures were closely related to scallop tissue samples, suggesting that it is likely to be the main food source for the wild P. novaezelandiae. Scallops from the two sampling sites exhibited similar reproductive cycles and utilization of nutrients. Gametogenesis started in winter, and took place at the expense of carbohydrates stored in adductor muscles. Spawning events were recorded in spring (October−November) and summer (January−March), and the energy demand required during spawning events was supported by digestive gland protein. Gonad re-maturation between spring and summer spawnings were supported by the utilization of digestive gland lipids. The reproductive condition and nutrient content of scallops were then studied during the spawning season (October 2013) in wild populations and within experimental conditions (fed with a commercial microalgal diet; Shellfish Diet 1800®) in an aquaculture laboratory, in order to identify condition and nutrient requirements for scallop cultivation in New Zealand. Field scallops (feeding on natural food sources) spawned just before the end of the experiment, while experimental animals reached gonad maturity at the end of the experiment, but did not spawn. The trend in gonad maturation for field and experimental animals indicates that there was a lag time of about 2 weeks, and that this lag is likely due to nutritional stress associated with the shift from natural food sources to the mixed microalgal formulated diet provided in the laboratory. Results indicate that experimental scallops had lower nutrient (carbohydrates, protein, lipids and total energy) reserves stored in adductor muscle tissues compared to wild animals, but both field and experimental animals utilized muscular reserves (especially carbohydrates and protein) to support reproductive activity. The fatty acid profiles revealed that polyunsaturated fatty acids (PUFA) were found in significantly lower quantities in gonad tissues of scallops from the laboratory compared to those in the field. This thesis shows that P. novaezelandiae utilizes energy reserves from both adductor muscle and digestive gland to cover the full cost of gametogenesis. In addition, cultivation environments using microalgal diets are conducive to condition P. novaezelandiae, but the optimal nutrient requirements for an efficient aquaculture production of this species needs further investigation. It is recommended by this thesis that future investigation on the conditioning requirements for P. novaezelandiae will be the next step for New Zealand scallop fisheries.

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  • Design foundations: Towards a model of style grammar in creative drawing

    Sweo, Jennie (2017)

    Doctoral thesis
    Victoria University of Wellington

    A style grammar is a principled rule set that governs the organization of very complex ideas. It allows for the examination of underlying structures which are often times obscured. Style grammars have been developed for many fields such as writing, fashion and architecture but to date there is no style grammar for creative drawing. The research identifies the necessary visual features and core traits associated with each feature towards developing such a model for creative drawings. Then operational measures are defined using the computer to extract and measure the core traits of those features towards developing a model of style grammar in drawing. These visual features include line, tone, and depth. Core traits include line length, line width, line expressiveness, local tone, global tone, texture, pattern, outline, shape, and position. A multidimensional scaling (MDS) using input from 27 subjects, 10 art experts and 17 novices, supported the overall list of visual features and added the dimension of smudge to the list. A second MDS sort discusses issues with images and large art categorical sorts from the standpoint of both human perception and machine measures that were obtained using feature extraction. It was concluded from the results of the second MDS that large art categories were too broad to be useful in evaluating measures to develop the model. Further analysis was run using only drawings from three artists, two impressionists to compare similarity and one expressionist for dissimilarity to determine if the machine measures of the core traits of the visual features were able to differentiate smaller groupings of consistent drawing styles. Using the computer allowed for systematic and objective procedures to be used to obtain measures. The multinomial logistic regression showed high significance for all the traits except marginal significance for line length and no significance for depth. Binomial logistic regressions run on each pair of artists showed high significance for all the traits except depth. The combined positive results of the first MDS card sort and the binomial and multinomial regression analysis provide proof of concept and offer strong support towards the development of a model of style grammar for creative drawings. Implications for teaching drawing using the identified visual features and core traits are offered. The outcomes and analysis provided in this research currently support a general practice rule in design reuse and intelligent borrowing that suggests first smudge, then depth, then tone, and then line quality are the most significant elements to use for style comparison. Discussions for future research including improved measures and other types of perception testing are provided towards further development of the model.

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  • Modes and Progression of Tool Deterioration and Their Effects on Cutting Force During End Milling of 718Plus Ni-based Superalloy Using Cemented WC-CO Tools

    Razak, Nurul Hidayah

    Doctoral thesis
    Auckland University of Technology

    Understanding the detailed progression of cutting tool deterioration and how deterioration affects cutting force (F) during milling of difficult-to-cut Ni-based superalloys is important for the improvement of machinability of the alloys. It also serves to clarify whether and how an F-based method for monitoring tool deterioration is possible. This understanding is however far from sufficient, as is explained in this thesis after a comprehensive review of the literature. The aim of the present research is thus to determine and explain the modes and progression of tool deterioration and how cutting forces may vary due to the various deterioration features of the cutting tool edge. Experimentally, the study started by using a typical milling condition with both uncoated and coated cemented carbide (WC-Co) tools. Milling was conducted in either dry or wet conditions. After each pass of a selected distance, the tool was examined in detail in the same manner. Thus, tool deterioration could be monitored more closely and failure mechanisms could be identified and explained. Following on the study on determining the modes of tool deterioration, the progress of deterioration and cutting forces during milling were carefully monitored. Through analysing the monitored tool deterioration features and measured force data, how edge wear, chipping and breakage in cutting edge and beyond the edge contribute to the variation of cutting forces could be studied and better understood. Furthermore, experiments have also been conducted using workpiece in a hardened state. It has been observed that the commonly recognised build-up layer in the initial stage does not significantly affect the tool deterioration process. Instead, from the beginning of milling, cutting forces/stresses could cause small chipping locally in the initially sharp cutting edge. Fracturing locally with cracks propagating outside the cutting edge along the flank face in the subsurface region could also take place and was consistent with the direction of the cutting force. There was an initial period of time during which a number of microcracks had initiated in and near the cutting edge on the rake face side. These cracks soon propagated resulting in extensively fracturing and blunting of the tool. Coating of the tools had provided little protection as in the cutting edge area the coating had broken away soon after milling started. The major tool failure mode was Co binder material having heavily deformed to fracture, separating the WC grains. Loss of strength in binder material at cutting temperatures is also discussed. As would be expected, the general trend of how F increased as the number of pass (Npass) increased agreed with the general trend of increasing flank wear (VB) as Npass increased. However, the F-VBmax plot has shown a rather poor F-VBmax relationship. This was the result of the different modes of tool deterioration affecting VBmax differently, but VBmax did not represent fully the true cutting edge of the deteriorating tool insert. Chipping and breakage of the inserts confined in the cutting area, resulting in the significant blunting of the edge area, causing a high rate of F increase as VBmax increased and completely deteriorated 6 minutes within of milling time. Fracturing along the face of thin pieces effectively increased VBmax without increasing the cutting edge area and without further blunting the edge, thus no increase in F was required. The high rate, meaning high ∆F/∆VBmax, results from the effect of the edge deterioration/blunting on the reducing the effective rake angle and thus increasing F is suggested and discussed. The use of coolant has not been found to affect tool deterioration/life and cutting force. Explanation for this will be given considering the deformation zone for which coolant does not have an effect. An increase in feed rate has reduced the tool life and the mode of deterioration has become more edge chipping/fracturing dominant, leading to a better F-VBmax relationship. Finally, it has been observed that the rate of tool deterioration is not higher when the hardened workpiece material is used. The modes and progression of deterioration of tools using hardened workpiece were determined to be comparable to those when annealed workpiece was used. Furthermore, the trends of increase in cutting force as milling pass increases have been observed to be similar for both workpiece material conditions. Interrupt milling experiments followed by hardness mapping has indicted that the workpiece hardened state has not affected the deformation area significantly, although increase in hardness in a similar amount in the severe deformed region has been found for both cases. It is suggested that temperature increases in the narrow deformation zone to be similar for both workpiece conditions and at high temperatures hardening mechanisms do not operate, and thus cutting force values do not differ significantly. Furthermore, the modes and rate of tool deterioration on the hardened workpiece was comparable to the annealed workpiece.

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  • Associations between language, false belief understanding and children's social competence

    Buehler, Daniela (2016)

    Doctoral thesis
    University of Canterbury Library

    The current longitudinal study explores associations between language and social competence. Specifically, I examine whether language variables, such as using and hearing mental state words and specific aspects of communication, are linked to social competence through the social skill of perspective-taking and the ability to understand that other people might hold a false belief. A cohort of 67 children were assessed at three time points. The initial assessment took place at ages of 24–30 months; and the first follow-up assessment occurred at ages of 41–49 months, and the outcome assessment took place when the children were aged 52–60 months. Data were collected through standardised tests of language and cognition, coded spontaneous play-based language samples, a nonverbal false-belief task and parental questionnaires that represent aspects of Cavell's (1990) social competence model. The findings indicated that mothers' connected communication played a role in their children's social development. Mothers who more often referred to their 2-year-old child's utterances, reformulated, elaborated or answered to them in an appropriate manner described their children as socially more advanced later in development compared to mothers who were less connected in communication with their child. However, mothers' connectedness in communication with their children was no longer a significant predictor once the children's expressive and receptive language abilities were added to the regression model. Children's expressive vocabulary including words to refer to mental states at the age of two years was a predictor of their social competence at five years. Children who produced more words in general and more often used words to refer to their own and others’ mental states such as emotions, desires or cognition at two years had fewer social difficulties at five years than children who produced fewer words and made fewer references to mental states. No relationship was found among mental-state talk, communication connectedness and false-belief understanding and between false-belief understanding and social competence. These findings indicate that being able to express oneself and to refer to mental states helps young children to interact more effectively in the social world. Therefore, considering the impact that early language competency has on social development identification of children with language difficulties becomes even more important.

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  • Development and Analysis of a Solar Humidification Dehumidification Desalination System

    Enayatollahi, Reza

    Doctoral thesis
    Auckland University of Technology

    In this thesis, an investigation was performed in order to understand the performance of a solar humidification dehumidification (HDH) desalination system. Initially, a mathematical model of the system, including solar water heater, condenser, economizer and long duct humidifier was developed. Using a sensitivity analysis, it was found that improving the intensities of heat and mass transfer in the humidifier would significantly enhance the yield of the system. This led to the development of a novel cascading humidifier, in which air was directed through a series of falling water sheets. An experiment was performed to first identify and characterise flow regimes in the crossflow interactions, and from this, to develop correlations to describe the heat and mass transfer for such interactions. Four flow regimes were identified and mapped based on the Reynolds number of the air and the Weber number of the water. Subsequently, Buckingham’s π theorem and a least squares analysis was employed to develop a series of empirical relations for Nusselt and Sherwood numbers. This led to the proposal of three new dimensionless numbers named the Prandtl Number of Evaporation, the Schmidt Number of Evaporation and the Lewis Number of Evaporation. These describe the transfer phenomena in low temperature evaporation processes with crossflow. Finally, the new correlations for Nusselt and Sherwood numbers were used to develop a model of a cascading humidifier, incorporated in a solar HDH system. It was found that a cascading humidifier enhances the yield of the HDH system by approximately 15%, while reducing the evaporation area to approximately a quarter of that required in a long channel humidifier.

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  • The Role of Ecology and Molecular Evolution in Shaping Global Terrestrial Diversity

    McBride, Paul Derek

    Doctoral thesis
    Auckland University of Technology

    The density of species varies widely across the earth. Most broad taxonomic groups have similar spatial diversity patterns, with greatest densities of species in wet, tropical environments. Although evidently correlated with climate, determining the causes of such diversity differences is complicated by myriad factors: many possible mechanisms exist to link climate and diversity, these mechanisms are not mutually exclusive, and they may overlap in the patterns they generate. Further, the importance of different mechanisms may vary between spatial scales. Generating uneven spatial diversity patterns in regions that are below equilibrium species richness requires either geometric or historical area effects, or regional differences in net diversification. Here, I investigate the global climate correlates of diversity in plants and vertebrates, and hypotheses that could link these correlates to net diversification processes, in particular through climate-linked patterns of molecular evolution. I first show strong climate–diversity relationships only emerge at large scales, and that the specific correlates of diversity differ between plants and animals. For plants, the strongest large-scale predictor of species richness is net primary productivity, which reflects the water–energy balance at large scales. For animals, temperature seasonality is the strongest large-scale predictor of diversity. Then, using two clades of New World passerine birds that together comprise 20% of global avian diversity, I investigate whether rates and patterns of molecular evolution can be linked to diversification processes that could cause spatial diversity patterns in birds. I find that most substitution rate variation between phylogenetically independent comparisons of avian sister species appears to result from mutation rate variation that is uncorrelated with climate. I provide evidence of nearly neutral effects in mitochondrial coding sequences, finding a significant, negative correlation between non-synonymous substitution rates and population size. Using phylogenetically independent comparisons, I also find that birds in low temperature seasonality, and isothermal environments, and birds with small elevational ranges have increased non-synonymous substitution rates, indicative of relaxed purifying selection. Other climate variables have no direct effect on molecular evolution. Molecular evolutionary patterns are dominated by mutation rate variation. Recovered patterns were stronger when mutation rate variation was controlled, indicating that such variation is a source of noise in analyses, and may be generally problematic across short genetic distances for analyses using mitochondrial genes. I bring these findings together with emerging literature to outline a framework for understanding net diversification patterns. Maintaining adaptations to climate, and the limits of those adaptations have population-genetic consequences that can affect lineage persistence and the processes of speciation and extinction in a fashion that is consistent with observations at multiple levels of diversity.

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  • Narrating connections and boundaries : constructing relatedness in lesbian known donor familial configurations.

    Surtees, Nicola Jane (2017)

    Doctoral thesis
    University of Canterbury Library

    In a time of unprecedented possibilities for intimate life, lesbian known donor reproduction is an emerging form of kinship practice. While experienced as unique to the biographies of particular lesbian couples, known donors and their partners, practices of relatedness occur against the background of neoliberal discourses, processes of normalisation and legislative frameworks that are increasingly responsive to the rights claims of lesbian parents. This thesis investigates this phenomenon in contemporary New Zealand. Examining the meanings attached to cultural constructs such as ‘kinship’, ‘family’, ‘parenthood’, ‘motherhood’ and ‘fatherhood’, the thesis illustrates how familial boundaries and sets of relations are narratively constructed. The research draws on interviews with 60 women and men across 21 lesbian known donor familial configurations at different stages of forming family through known donor insemination, focusing in depth on nine core family narratives. Participants included lesbian parents and parents to be, gay and heterosexual known donors, and partners of donors. The thesis argues that participants are innovative in conformity and through constraint. Although the participants live amid the same dominant heteronormative public narratives, they are differently normative. They pursue different familial scenarios, which creates different possibilities for lesbian couple and parenting selves and identities relative to donors and their partners. The picture emerging suggests donors and partners remain supplementary to lesbian couples. How their status is expressed is a central theme of the thesis that demonstrates the power of neoliberal agendas of personal responsibility, freedom, agency and choice. Tensions between a sense of empowerment and constraint in family-building activities are closely linked to these agendas. Contributing to debates about the operation of homonormativity in a neoliberal context, this thesis explores the discursive power of heteronormative family models and the implications of this for innovation in the intimate lives of same-sex and heterosexual subjects.

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  • Numerical modelling of groundwater - surface water interactions with the Double-Averaged Navier-Stokes Equations.

    Dark, A. L. (2017)

    Doctoral thesis
    University of Canterbury Library

    The ability to model groundwater and surface water flows as two interacting components of a single resource is highly important for robust catchment management. Existing methods for spatially-distributed numerical modelling of flow in connected river-aquifer systems treat rivers and aquifers as separate sub-domains, with different governing equations for the flow in each. Mass-fluxes exchanged between the sub-domains are modelled using one of several coupling methods, which do not accurately represent the physics of the flow across the interface between the surface and subsurface flows. This can be problematic for model stability and mass conservation. This thesis investigates the feasibility of modelling interacting surface water and groundwater flows in a single domain, using a single system of equations. It is shown that the governing equations in existing numerical models for river and aquifer flow can be derived from the Navier-Stokes Equations. A time- and space-averaged form of Navier-Stokes Equations, the Double-Averaged Navier-Stokes (DANS) Equations, can be used to model both groundwater and surface water flows. The volume- averaging process allows the porous medium to be represented as a continuum. A novel two-dimensional numerical model is developed from the DANS Equations to simulate flows in connected groundwater and surface water systems. The DANS equations are solved using the finite-volume method. The model simulates two-dimensional flow in a vertical slice. This allows the horizontal and vertical velocity components and pressure to be modelled over the depth of a stream and the underlying aquifer or hyporheic zone. The model does not require the location of the interface between surface and subsurface flows to be specified explicitly: this is determined by the spatial distribution of hydraulic properties (permeability and porosity). The numerical model handles the transition between laminar and turbulent flows using an adaptive damping approach to modify the terms in a single-equation turbulence model, based on a locally-defined porous Reynolds number, Rep. This approach removes the need to specify a priori whether flows in any part of the domain are laminar or turbu lent. Turbulent porous media flows can be simulated. The model is verified for porous-media and clear-fluid flows separately, before being used to simulate coupled groundwater - surface water flow scenarios. For porous-media flows with low Rep the numerical model results agree exactly with Darcy’s Law. The value of Rep at which the model results begin to deviate from Darcy’s Law is consistent with published values. For turbulent clear-fluid flows the time-averaged velocity and turbu lent kinetic energy (TKE) results from the numerical model are ver ified against a RANS model and published data. A good match is achieved for both velocity and TKE. Energy grade-line slopes for free-surface flows simulated in the numerical model are a reasonably good match to equivalent results to the one-dimensional hydraulic model HEC-RAS. Idealised river-aquifer interaction experiments are conducted in a lab- oratory flume to provide verification data for the numerical model. An innovative combination of optical flow measurement and refractive- index-matched transparent soil is used to measure two-dimensional velocities and turbulent statistics in laboratory flow scenarios that simulate flow in both losing and gaining streams, and the underlying connected porous layer. The “gaining stream” laboratory scenario is replicated using the numerical model. The model simulates the key features of the mean flow well. Turbulent statistics deviate substantially from the laboratory results where vertical velocities across the surface-subsurface interface are high, but are a better match elsewhere. The “losing stream” laboratory results are unable to be reproduced with the numerical model. Results for a similar scenario with lower outflow velocities are presented. These results are qualitatively consistent with the laboratory results. The numerical model is expected to perform better in simulations of field-like conditions that involve less extreme gradients than the laboratory scenarios.

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  • Gender, class and modernity : reproductive agency in urban India.

    Kohli, Ambika (2017)

    Doctoral thesis
    University of Canterbury Library

    The decreasing female child sex ratio in contemporary India is often linked to the small family norm. However, the decline of sex ratio has raised interesting questions regarding women’s involvement in decision making in the context of female-foeticide and managing family size. Are women victims or actors while making their reproductive choices? What are their reproductive interests, and how do they achieve them? This study investigates how urban-middle class women from Delhi and Haryana make reproductive decisions in regards to family formation in modern urban neoliberal society. Motherhood, abortions, and gender relations are discussed with reference to the main themes of son-preference, increasing social status of daughters, family planning, family building strategies, reproductive health and well-being. Further, because of the prevalence of son-preference it is crucial to understand what kind of status daughters are accorded in contemporary urban Indian society. This study addresses this by looking at participants’ differing perceptions and expectations for their daughters and sons, and in particular how daughters are treated. The status of daughters is documented through an examination of current forms of gender discrimination against them, and also the different kinds of opportunities that they are provided by their parents. These issues are explored through a qualitative study of the reproductive decision making of 45 educated married urban middle-class mothers from Delhi and Yaumuna Nagar (region of Haryana), India. Snowballing was used to recruit participants, and the fieldwork was carried out during two visits to India. I chose Delhi and Haryana because both of these regions have collective and patriarchal family structures. For instance, in these regions joint families are quite common among the middle-class and fathers or a male family member are often the head of the family. Furthermore, Delhi and Haryana have a low female child sex ratio, as recorded in the 2011 census, but have shown slight improvement in comparison to 2001 figures. Therefore, this study will provide insights into how women practice their reproductive agency in highly collective and patriarchal settings of their affinal families. These families are in the process of rapid socio-cultural changes, including change in gender roles and opportunities for daughters. I will examine women’s decision making process, including practices of negotiating and resistance strategies they develop. xvi I will then discuss how women engage with different forms of modern, spiritual and traditional technologies in order to maintain their reproductive health and well-being, and how they attempt to give birth to a son while maintaining the norm of small family size. This will suggest that society and technology are mutually constitutive. Finally, I will explore how social transformation has influenced the gender relationships which are discussed in relation to daughters’ improving status and also the different forms of discrimination currently used against them. However, throughout the research the patriarchal nature of urban neoliberal Indian society and the idea that a man is needed to support a woman and for her protection has been highlighted.

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  • Developing a flood hazard analysis framework in the Cuvelai Basin, Namibia, using a flood model, remote sensing, and GIS.

    Persendt, Frans C. (2016)

    Doctoral thesis
    University of Canterbury Library

    Worldwide, more than 40% of all natural hazards, and about half of all deaths, are the result of flood disasters. In the Cuvelai River Basin (CRB), northern Namibia, flood disasters have increased dramatically over the past half-century, along with associated economic losses and fatalities. The increase in hydro-meteorological hazards such as floods are mainly attributed to intense urbanisation, changing land-use patterns and a changing climate. These hazards are exacerbated in semi-arid and data-sparse (SADS) regions such as the CBR, because of declining and/or non-existent hydro-meteorological infrastructure. In addition there is a lack of long-term continuous records that is needed to enhance the implementation of traditional flood risk management strategies, whether structural or non-structural, to mitigate hydro- meteorological hazards. This thesis developed a systematic framework that has quantified the uncertainties associated with the hydrological cycle that preclude the development of flood risk management strategies. The framework is based on free-data and open-data and software that is available online. It used remotely sensed data validated against ground-based observational data, where available. The particular components of the hydrological cycle that are assessed are: precipitation, surface runoff (discharge), surface water extent and surface water movement pathways (drainage networks). Hydrologic modelling was used to model the water fluxes in order to derive basin as well as flood characteristics of the study area. The framework can be used as a benchmark for the development of flood risk management policies that will enable SADS regions to mitigate the severe effect hydro-meteorological disasters in the Anthropocene. The flood hazard analysis framework (FHAF) developed for this study consists of two steps: (a) preliminary analysis and (b) hazard estimation. The preliminary analysis enable the development of a hydro-meteorological (floods and droughts) archive using different data sources as well as identifying where more analyses are needed to reduce uncertainty while hazard estimation provide the frequency and magnitude of the hazard. As a result of the growing concern about flood risk, identifying the extreme precipitation events that cause hydro-meteorological disasters is essential. Hence, the preliminary analysis step of FHAF developed a database (a). An up-to-date and broad analysis of the trends of hydro-meteorological events within the CRB was performed. The derived events were also validated against data from other sources. The risk estimation step involved components of the hydrologic cycle that are crucial in determining flood risk and that play an important role in enhancing uncertainty. Precipitation is one of these crucial components, to estimate and validate, especially in the trans-boundary SADS CRB. Four commonly used operational satellite-based rainfall estimation (SBRE) products were rigorously validated and inter-compared on monthly, seasonal, and annual timescales. Rainfall data from gauged stations were compared against SBREs as well as simulated data from a Regional Climate Model (RegCM4) model. Point-to-nearest-pixel and pixel-to-pixel methods were used to validate gauge data against high spatial resolution (0.25o) SBREs data for a period from 2008 to 2014. Validation was performed on a monthly, seasonally, and annual basis as well as taking the long-term mean, whilst error statistics were used to determine the accuracy of the SBREs when compared to the observed rainfall gauge values. Results indicated good statistical relationships between the ground-based gauge stations for some SBREs. Results will help to understand, and ultimately expand, our understanding of the climatologies within this SADS region and will also provide valuable information on the error structures of SBRE products that might be ingested into hydrologic models for water resource management. The results also help to quantify the improvements (bias correction) that are needed for these SBRE products to be useful for water resource and risk management applications. The second component, surface water pathways (drainage networks), is imperative to determine flood inundation extent, which relate to hazards. Also, accurate delineation of drainage networks is crucial for hydrological modelling and hydraulic modelling, and the comprehension of fluvial processes. Channels from topographic maps (blue lines) were compared to those from hydrologically corrected and uncorrected light detection and ranging (LiDAR) DEMs (digital elevation models), heads-up digitised channels from high-resolution digital aerial orthophotographs, field-mapped channels and auxiliary data. The maximum gradient deterministic eight (D8) GIS algorithm was applied to the corrected and uncorrected LiDAR DEMs using two network extraction methods: area threshold support and curvature/drop analysis. Results will aid national mapping agencies in SADS regions to modernise their national hydrography datasets and to account for changing land surface conditions that can affect channel spatial arrangements over time. The third component, deals with the amount, frequency, and magnitude of surface water runoff (discharge). Sustainable management of water resources as well as mitigating hydro- meteorological natural hazards such as flooding and drought requires the precise understanding of the spatio-temporal distribution of water especially in SADS regions where data from various global datasets are used to compensate. Results suggested that input data be ingested in hydrological models especially if the data are to be used especially for water resources estimations and for understanding flood-producing processes. The last component, surface water extent (flood inundation), was also estimated in this study. The mapping of spatial inundation patterns during flood events is important for environmental management and disaster monitoring. This study detected and compared the spatial extent of flood inundation at the peak of three major flood events (2008, 2009, and 2011) in the CRB. The study follows a multi-spectral and multi-sensor approach to identify the flood inundation for each flood event at peak modelled discharge. Results indicated that the quantification of flooding spatial extent can help to provide valuable information to FHAFs and hence potentially improve hydrologic prediction and flood management strategies in ungauged catchments. Furthermore, given the globally availability of satellite- based precipitation and river discharges, this proof-of-concept study can have substantial implications on flood monitoring and forecasting in ungauged basins throughout the globe.

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  • The spectra of transition-metal ions in solids

    Johnstone, I.W. (1975)

    Doctoral thesis
    University of Canterbury Library

    The results of an investigation of the Raman and infrared spectra of cobaltous ions in cadmium-chloride, cadmium-bromide, and manganese-chloride, and of cobalt-chloride are presented. The cobalt ions substitute for the cation in these crystals and experience a trigonal crystal-field which splits the lowest ⁴T₁g (⁴F) cubic-field term into six Kramers doublets with energies in the range 0-1200 cm⁻¹. The Raman spectra, measured as a function of temperature and of cobalt concentration show all five single ion electronic transitions together with several lines due to cobalt ion pairs. The infrared spectra comprise both magnetic-dipole allowed electronic transitions and electric-dipole allowed vibronic lines and bands. They confirm the identity of the electronic transitions seen by Raman scattering and also yield information concerning the lattice modes of the host and the possible interactions within cobalt ion pairs. The strong field matrices of the trigonal crystal-field and Zeeman interactions are calculated for the d³ (d⁷) configuration and quantitatively explain the experimental data. The crystal-field analysis provides single ion wavefunctions for further calculations which successfully explain the spectra of antiferromagnetic CoCl₂ and exchange coupled colbalt pairs in CdCl₂ (Co²⁺) and CdBr₂ (Co²⁺). A preliminary investigation of the infrared absorption of an oxygen-induced impurity site in CdCl₂-type crystals is also presented.

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  • Young People’s Experience of Post-Separation Fathering Where the Father has been Violent to the Mother

    Nelson, Pamela (2017)

    Doctoral thesis
    Victoria University of Wellington

    My intention in undertaking this research was to examine young people’s experiences of living with their father following parental separation where their father has been violent to their mother. To date there is little knowledge of children’s post-separation experiences of fathering or of the parenting abilities of partner abusive men. This study takes a feminist approach and is informed by scholarship on family issues, childhood studies and the sociology of the child. The study was guided by hermeneutic phenomenology and thematic analysis was used to analyse the data. Twenty young people aged 18 to 26 took part in the study and face to face interviews were carried out over a one year period. The findings revealed that some fathers were overly punitive in their parenting style with a number of fathers continuing to be physically and/or emotionally abusive to their children. Authoritarian or permissive parenting practices were also identified and a number of fathers were shown to be neglectful, making little effort to bond with their children or provide quality care. In cases where fathers were unable to accept the break-up and move on this was also shown to have an adverse effect on their ability to parent effectively including an inability to co-operate with children’s mothers. In contrast, the majority of mothers were shown to be central to children’s lives undertaking most of the caring responsibilities. Mothers also recognised children’s changing needs as they grew older, encouraged autonomy, and contributed to children’s social development and maturity by trusting their judgement. However, this was not necessarily a protective factor against difficulties that participants have experienced as young adults. A time-share or full-time arrangement was revealed as being the most problematic for children although weekend contact could also pose a risk where pre-separation violence towards children had been severe. The study concluded that a safe outcome for children will require a shift away from a father’s right to contact, emphasising instead children’s right to a life free from abuse.

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  • Carbon and root system architecture : key regulators in nitrogen uptake in Lolium perenne L. and Brassica napus L.

    Guo, Qianqian (2017)

    Doctoral thesis
    University of Canterbury Library

    Nitrogen (N) is an essential macronutrient that limits plant yield and productivity. In order to increase crop yield, considerable amounts of nitrogenous fertilizers are applied to agriculture systems each year. However, about 25-70% of the applied fertilizer in ecosystem has been leached and released to the environment, in the form of NO, N₂O and NH₃, aggravating environmental pollution. Therefore, increasing nitrogen use efficiency in agriculture systems is essential to maintain the food production while alleviating the deleterious environmental effects of applied N. The mechanisms linking C/N balance to N uptake and assimilation are central to plant responses to changing soil nutrient levels. Defoliation and subsequent regrowth of pasture grasses both impact C partitioning, thereby creating a significant point of interaction with soil N availability. Using defoliation as an experimental treatment, the dynamic relationships between plant carbohydrate status and NO₃⁻-responsive uptake systems, transporter gene expression and N assimilation were investigated in Lolium perenne. High- and low-affinity NO₃⁻ uptake were reduced in an N-dependent manner in response to a rapid and large shift in carbohydrate remobilization triggered by defoliation. This reduction in NO₃⁻ uptake was rescued by an exogenous 1% glucose supplement, confirming the carbohydrate-dependence of NO₃⁻ uptake. The regulation of NO₃⁻ uptake in response to the perturbation of plant C/N was associated with changes in expression of the nitrate high-affinity transporter LpNRT2.1b. Furthermore, NO₃⁻ assimilation appears to be regulated by the C/N balance, implying a mechanism that signals the availability of C metabolites for NO₃⁻ uptake and assimilation at the whole-plant level. This study also shows that cytokinins are involved in the regulation of nitrogen acquisition and assimilation in response to the changing C/N ratio. Root architecture is also a crucial component that impacts the capacity of plants to access nutrients and water. By using the recently developed package RootNav, comprehensive morphological changes in root system architecture in response to different N sources were investigated in Brassica napus. In order to avoid a light-induced morphological and physiological responses affecting whole plant growth, an existing solid agar vertical-plate system was modified so that to allow roots to be shielded from light without sucrose addition and the emerging shoot to be grown without direct contact with the medium, thereby mimicking more closely the environmental conditions in nature. The results of 10-days-old B. napus seedlings showed that total root length, LR density and root exploration area decreased with increasing external NO₃⁻ concentrations from 0.5 mM to 10 mM. The application of 0.5 mM NO₃⁻ induced more branching in the root system relative to the treatments with higher N concentrations (5 mM and 10 mM). The proportion of biomass allocation occupied by roots was greater in the low NO₃⁻ treatment relative to the high NO₃⁻ treatments, reflecting the fact that plants invested more resources in their roots when nutrient uptake from the environment was limited. In treatments of increasing NH₄⁺ concentration from 0.5 mM to 10 mM, primary root length, total root length, LR branching zone, LR density and root exploration area were reduced. These results indicated that NH₄⁺ toxicity usually leads to a stunted root system in B. napus, whereas a low concentration of NH₄⁺ is an optimal nitrogen resource for plant growth. Increasing L-glutamate concentration from 0.01 mM to 0.1 mM suppressed primary root length, whilst the LR branching zone did not change in the different L-glutamate treatments, suggesting that L-glutamate even at micromolar level could arrest primary root growth and LR branching in B. napus. By using in situ ¹⁵N isotope labelling, morphological and molecular phenotypes generated pharmacologically were employed to investigate whether the impacts of contrasting root traits are of functional interest in relation to N acquisition. Brassica napus L. were grown in solid medium containing 1 mM KNO3 and treated with cytokinin, 6-benzylaminopurine, the cytokinin antagonist (PI-55), or both in combination. The contrasting root traits induced by PI-55 and 6-benzylaminopurine were strongly related to ¹⁵N uptake rate. Large root proliferation led to greater ¹⁵N cumulative uptake rather than greater ¹⁵N uptake efficiency per unit root length. This relationship was associated with changes in C and N resource distribution between the shoot and root, and in expression of BnNRT2.1. The root/shoot biomass ratio was positively correlated with ¹⁵N cumulative uptake, suggesting the functional utility of root investment for nutrient acquisition. These results demonstrate that root proliferation in response to external N is a behaviour which integrates local N availability and systemic N status in the plant. In conclusion, using two major economic forage species, L. perenne and B. napus, this thesis illuminates the impacts of carbon and root system architecture on N uptake. This work contributes to our understanding of the mechanisms regulating N uptake and will help further in efforts to improve nitrogen use efficiency.

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  • An integrated water-electricity market design for multi reservoir, mixed operation.

    Mahakalanda, Indrajanaka (2016)

    Doctoral thesis
    University of Canterbury Library

    Water markets are often regarded as the most promising method of managing this increasingly important natural resource, but the literature on water market concepts is only emerging. Most of the focus is on physical trading arrangements, but financial property rights appear both conceptually and practically appealing, as a way to develop commercial and organizational arrangements to improve liquidity and ultimately increase efficient resource use. This thesis focuses on market arrangements to manage hydrology dependent surface water supplies, where consumptive and/or non-consumptive use occurs in a network with storage. Binding resource constraints create temporal and locational price differences. Moreover, the uncertainty about price differentials creates barriers to trade. Participant bids, reflecting their marginal use values, are assumed to be cleared by a benefit-maximising optimisation, such as Stochastic Linear Programming. This also creates price differences between locations, and time periods, and causes the market to accumulate a “settlement surplus” of rents associated with resource constraints. This thesis draws on the Financial Transmission Right (FTR) concepts developed for electricity markets to outline a general structure of financial hedging instruments that could be used to deploy this settlement surplus to hedge against price risks, across space and time. We also consider a swing option based approach, which bundles the above rights to create a virtual “slice of system” model that could be practically and conceptually appealing to both aggregated and disaggregated hydro reservoir systems. While only preliminary, our discussion of these options suggests that developments along these lines may be important in creating a water market environment that is acceptable to potential consumptive and non-consumptive participants. The remainder of this thesis is about the problem of intra-period consumptive and non-consumptive water allocation in a mixed-use catchment. We develop a deterministic nodal Constructive Dual Dynamic Programming (CDDP) procedure which implicitly clears a market determining both consumptive and non-consumptive water allocations, across all nodes in a catchment with a single reservoir. Consumptive users extract water from the system, so each unit of water flow can only be used for a single consumptive use. A non-consumptive user transfers water from one node to another, extracting some benefit, or incurring some cost. Arc flow bounds may limit the opportunities for using water at the nodes. Costs can be associated with arc flow bounds and distributary demands to represent in-stream and environmental reserve flows enforced using penalty costs. The algorithm constructs the intra-period demand curve for release by sequentially forming marginal water value curves at each node, passing these curves towards the reservoir. This approach can generate net demand curves representing all possible market-clearing solutions at nodal and user levels. It can also be used to construct net demand curves for water release from the reservoir, in each period, which could then be used in a stochastic inter-temporal CDDP model to construct marginal water value curves stored in the reservoir over an appropriate time horizon. Several variants on this approach are explored. We discuss extending the procedure to assess the marginal value of water stored in two inter-connected reservoirs in a mixed-use catchment. A “lower level” intra-period CDDP is applied to construct a two dimensional “demand surface” for transfer, representing the marginal benefit from net release into either end of the inter-reservoir chain between the two reservoirs. Then a higher level inter-period CDDP demand-curve-adding method could be deployed to strike the optimal trade-off between the current release demands for the inter-reservoir chain and other sub-trees leading from the two reservoirs and the future storage demands.

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  • Integrated response as a process for enhancing the incident command system

    Fakuade, Dolapo (2017)

    Doctoral thesis
    University of Canterbury Library

    The devastating societal impacts of disruptive events have emphasised the need for more effective and unified emergency response arrangements. While policies that guide strategies, measures or approaches are not lacking in the emergency sector, they tend to be inadequate for response and relatively ineffective during response to large-scale or unprecedented events. This research critically examines theoretical bases and practice systems for emergency response, in order to identify useful community functions which can be integrated with emergency management response. The aim is to develop an integrated response framework that can be adopted to improve response to disruptive events. The data for this research were gathered through case study analyses of communities in Christchurch, which provided context for and helped define the scope of community functions required for emergency response. Data were also collected in semi-structured interviews and focus group sessions with different community groups and organisations, emergency management professionals, and officials working in Christchurch City Council. The analysis indicates that relevant functions exist within communities, and that four types of community functions can be used for improving emergency management response. Community functions identified were seen to possess relationships, interactions and qualities lacking in the emergency sector; characteristics that are essential for operational command and control response processes. The major research outcome is the development of a framework that integrates community functions with command and control structure as a contribution to improving response to disruptive events.

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  • Scott’s and Shackleton’s huts : Antarctic heritage and international relations.

    Lintott, B. J. (2016)

    Doctoral thesis
    University of Canterbury Library

    Three British wooden huts remain on Ross Island, Antarctica from Scott’s and Shackleton’s expeditions: the Nimrod Hut and the Terra Nova Hut were operational bases with accommodation, laboratories, darkrooms and used as workshops while Discovery Hut was a general purpose storeroom, workshop and shelter. In 1957, the New Zealand Government decided that it would retain and maintain the huts in situ as a geopolitical statement to the United States of America that New Zealand remained firm in its Antarctic territorial claim. Throughout the Huts Project (1957 onwards) there have been two central issues. The first are the technical and financial challenges of retaining the huts (temporary wooden buildings) in their historical settings given that the Antarctic environment is one of the most hostile on the planet, and how they should be interpreted. Associated with this is a prevailing myth that items in the Polar Regions can remain frozen in a state of “timelessness”. This thesis argues that this misinformed the “Huts Project” in its early years (once removed from the ice, artefacts quickly began to decay) and that in the latest restoration many artefacts have been treated so as to reproduce their original appearance, removing the patina of age and compromising their authenticity. The second is how New Zealand has conducted its interrelationships regarding the huts with the United States of America and the United Kingdom. The United States is New Zealand’s strategic ally and provides logistical support for its Antarctic endeavours and whilst it respects the huts as being historic it does not accept that they could enhance a future Antarctic territorial claim by New Zealand. The United Kingdom retains a strong cultural interest in the huts and has diplomatically, morally and – to a limited extent – financially supported the Huts Project. The Huts Project has been successfully utilized in cultural diplomacy since its beginnings however, since 2000, two activities proposed by New Zealand related to the huts have not proceeded due to diplomatic concerns. This thesis provides the cultural and historical background to New Zealand’s decision in 1957 to retain the huts and the subsequent external factors which influenced the project. A review of how the concept of “timelessness” was developed and deployed leads onto the substantive chapters about the heritage aspects of the project. The huts are then considered in the context of international relations and how they have been utilized and affected by diplomatic concerns. The thesis concludes by considering the possible futures of the huts, e.g. climate change, and areas for future research on Antarctic heritage and international relations.

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  • Upper atmospheric studies using radio meteors

    Wilkinson, Philip James (1973)

    Doctoral thesis
    University of Canterbury Library

    The atmospheric motions in the 80-110 km height region, and methods of measuring them are discussed. Wind measurements using radio meteor trails are then considered in greater detail and an account is given of the equipment at the field station of the Physics Department of Canterbury at Rolleston near Christchurch, as well as details of the data reduction methods used. An analysis of the errors associated with the collection of data indicates that approximately half the variance in an average of wind velocities observed in a thirty minute period is due to atmospheric variability. Results from the first year's observations suggest that the solar diurnal and semidiurnal tides are of roughly the same magnitude, this magnitude being in agreement with the latitudinal variations observed at other stations.

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  • Understanding Tsunami hazard knowledge and preparedness : before and after the 2010 Tsunami in Mentawai (Indonesia)

    Panjaitan, Berton Suar Pelita (2017)

    Doctoral thesis
    University of Canterbury Library

    This thesis is about the people from the Mentawai Islands (in Indonesia) in the context of disaster risk reduction. It results from a curiosity to deeply explore the tsunami hazard knowledge existing before the 2010 Mentawai tsunami occurred, and current tsunami preparedness. It also provides theoretical frameworks and key research concepts in relation to the issues. In order to understand the picture of Mentawai in the past and the present, the thesis also includes how the tsunami vulnerability progression has been formed. The progression presents from the era of solitary lives of the people, the era of destroying the traditional beliefs and tools, and up to the current era when the people live in unsafe locations. In order to obtain a full picture of the topics, a qualitative case study was designed with the consideration of how to plot and to show a number of illuminating facts. The people’s reflections and perspectives on their tsunami hazard knowledge before the 2010 tsunami occurred and devastated the islands, and their current tsunami preparedness, were examined. There were a number of substantial facts showing how the research participants captured, shared, and internalized explicit knowledge on tsunami hazards into their tacit knowledge. These processes occurred with little support from the district government and local non-government organizations, and were further impacted by their low socio-economic and educational status. The processes of the knowledge internalization were obviously influenced by their traditional beliefs and personal perceptions. Thus, the implications of the internalization were also different when it came to anticipating tsunami waves. Subsequently, the 2010 tsunami also brought different impacts to the participants. In the context of current measures, tsunami preparedness is applied differently at various levels, even though the people have experienced the 2010 tsunami. At the individual level, the participants mostly ignore their own preparedness, although some of the participants have specific personal efficacy and protective behaviour to avoid tsunami waves. At the household level, some would most likely leave their household members to save themselves, while others would try to help their family members. At the sub-village (dusun) level, the people tend to abandon the evacuation processes. Meanwhile, at the district level, although some important documents exist for the district government to follow, tsunami preparedness measures are less prioritized. The last parts of the study are how the local community of Mentawai can increase their capacity to encounter potential tsunamis. In the absence of modern technologies, the community has a number of traditional strategies to anticipate hazards and various opportunities to reduce their vulnerability. Developing coping capacity is essential for the people through implementing community early warning systems. These systems will provide risk knowledge, strategies to monitor the surroundings, understandable warning communication, and qualified response capability in the event of a tsunami. For the longer term, the leaders and the community need to work hand in hand to create an adaptive mechanism for living in Mentawai. This will be achieved by utilizing and reutilizing their traditional tools and strategies, and taking any opportunity to improve their livelihoods, and consequently, their coping and adaptive capacities to deal with tsunamis.

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  • The group theory of the harmonic oscillator with applications in physics.

    Haskell, T. G. (1972)

    Doctoral thesis
    University of Canterbury Library

    The possibility of the group SU₃ being used in the description of the (d+s)N and (d+s)npm many-electron complexes is examined by symmetrization of the Coulomb Hamiltonian. By dividing the Coulomb interaction into symmetry conserving and symmetry violating terms it is found that while the SU₃ scheme tends to give a better description in the (d+s)N case it shows no improvement over the configurational scheme in the (d+s)npm complex. The scheme is, however, very useful for the calculation of matrix elements of operators normally found in atomic spectroscopy and a complete set of symmetrized , scalar, Hermitian spin-independent two particle operators acting within (d+s)npm configurations is constructed. The radial wavefunctions of the harmonic oscillator are found to form a basis for the representations of the group 0(2,1) in the group scheme Sp(6,R) ⊃ S0(3) x 0(2,1). The operators Tkp = r2k are shown to transform simply under the action of the group generators. The matrix elements of Tkq and a selection rule similar to that of Pasternack and Sternheimer are derived. Finally the rich group structure of the harmonic oscillator is investigated and a dynamical group proposed which contains, as subgroups, the groups Sp(6,R), SU(3), H₄ and the direct product 0(2,1) x S0(3). Some remarks are made about contractions of groups, semidirect and direct products, and the generalization of the method to n-dimensions.

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  • Samoa: Exploring the Linkages Between Climate Change and Population Movements

    Flores-Palacios, Ximena

    Doctoral thesis
    Auckland University of Technology

    This Samoan study explores people’s experiences and understandings of climate change, including whether and how climate-related factors have influenced internal and international mobility patterns in the last 30 years. This interdisciplinary village and family-based study combined a Samoan worldview which acknowledges the place of traditional knowledge, values, beliefs and practices in people’s responses to climate change, and Western-based perspectives to set the knowledge base. Findings were: (a) that family resilience in dealing with the effects of climate change was grounded in fa’a Samoa norms including access to customary land and reciprocity, (b) that mobility has become an integral adaptation strategy as seen in relocation from coastal areas to inland customary lands, temporary and permanent migration to the capital, and overseas migration, and (c) that climate change effects have exacerbated differences among groups. Those with limited access to resources and support systems have fewer adaptation options and are less able to use mobility as an adaptive mechanism. The main implication for policy design is that the voices of people affected by climate change must be incorporated in both research and policy. While this may serve a political purpose, axiomatic also is that the voices carry considerable knowledge.

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