16168 research outputs found
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Dynamic mud deposition along the fluvial–tidal transition zone in the Waihou River, Aotearoa New Zealand
No full textThe fluvial–tidal transition zone (FTT) is a critical interface where complex interactions between river flow, tides, and sedimentation shape geomorphic systems and influence the dynamics of aquatic environments. However, few previous studies have integrated real‐time hydrodynamic data with sedimentary deposits. In particular, the range of depositional conditions over which mud accumulates remains poorly constrained, and little is understood about how these deposits are preserved in the stratigraphic record. To address this knowledge gap, we examined co‐located hydrodynamic instrument data and sedimentary deposits from the lower Waihou River, Aotearoa New Zealand. Results reveal that “dynamic mud” events, including fluid mud and rapidly deposited mud, dominate the spatial and temporal record, with few “static mud” events in which mud is deposited through gravitational settling. We suggest that dynamic mud conditions with the potential for deposition may occur throughout the tidal cycle, although cyclic tidal successions are never fully preserved. Many of the trends in sedimentation observed in studies of larger systems are not present in this small muddy river system, indicating the significance of climatic and river‐flow characteristics on the sedimentary record. This work underscores the importance of studying systems of multiple sizes across diverse climatic regimes to establish holistic facies models to reconstruct geological history accurately
A critical thinking thematic framework and observation tool for improved theory and developing secondary teachers’ instructional practice: Proof of concept
No full textTheoretical understandings of critical thinking, including how it is positioned and developed across educational contexts, remains contentious. While critical thinking features across school curricula internationally with increasing prominence as an educational priority for young people, efforts to explore and develop secondary teachers’ practices of critical thinking reveal diverse theoretical influences and instructional approaches, without reaching a consensus model of best practice. To address this, a new critical thinking thematic framework was developed towards reconciling theoretical tensions within the question of: what is critical thinking?, so that understandings of what it might look like as part of teacher instructional practice can be developed. Together with this thematic framework, a critical thinking observation tool and thematic coding guide were constructed to code and analyse teacher interview and classroom observations in order to guide a year-long investigation of secondary teachers’ beliefs and practices of critical thinking.
Applied across multiple studies within a design-based research project, this critical thinking thematic framework enabled the effective exploration and dissemination of secondary teachers’ perceptions and instructional practices of critical thinking across English, Social Science and Science subject contexts. Engaged as a community of practice, and supported with contextualised evidence, 28 participant teachers across five New Zealand secondary schools were able to reflect their beliefs and practices for future planning. Significant shifts in the frequency and conceptual nature of teachers’ beliefs and practices of critical thinking in response to professional development across repeated measures suggest that the Critical Thinking Thematic Framework and Observation Tool can be employed to produce consistent and reliable coding of beliefs and practices with effective researcher training
Demonstration of a strategy to create hybrid materials with stochastic 3D mesostructures
No full textA strategy to create hybrid materials with stochastic 3D mesostructures is proposed. The strategy entails the combination of commodity materials significantly different in terms of length-scale and their processing via induction sintering. Materials composed of a ferrous filaments mesostructure embedded in a sintered titanium microstructure are manufactured as representative example. The study shows that the presence of the random 3D mesostructure prevents the catastrophic fracture by impact of the hybrid materials
Tatua biosolids project
No full textThis study investigates the potential of waste activated sludge (WAS) as a sustainable and cost-effective soil amendment for agricultural use. Through field trials, glasshouse experiments, and laboratory analyses, the research evaluates the effects of WAS on soil properties, plant growth, nutrient dynamics, and heavy metal content, comparing its performance with other organic amendments such as vermicast, chicken litter, and SustaiN™, a commercial fertilizer.
The findings reveal that WAS application significantly enhances plant growth and yield. It also improves soil fertility by increasing organic matter content and promoting root development, though its high mineralization and nitrification rates necessitate careful management to minimize nitrogen losses. Heavy metal analysis indicates that while WAS contains elevated levels of metals like chromium and lead, these remain within permissible limits and do not significantly impact plant uptake.
Cost analysis highlights WAS as the most economical option at $120/ha/yr, compared to significantly higher costs for other amendments. However, the study identifies gaps in understanding odour management, long-term environmental impacts, and the effects of WAS on livestock health, which warrant further investigation.
In conclusion, WAS demonstrates strong potential as a viable alternative to traditional fertilizers, offering a balance between cost-effectiveness, nutrient availability, and environmental sustainability. Future research should focus on long-term field trials, expanded crop studies, advanced nitrogen monitoring, and economic feasibility to optimize its use in diverse agricultural systems. This study contributes to the growing body of knowledge on sustainable soil amendments, providing valuable insights for farmers, policymakers, and researchers aiming to enhance agricultural productivity while minimizing environmental risks
Microstructural evolution of UNS S32205 duplex stainless steel during cold rolling and subsequent annealing
No full textWe followed the microstructural evolution of UNS S32205 duplex stainless steel during cold rolling up to 79% reduction in thickness and at early stages of isothermal annealing at 1080ºC. Qualitative analysis of peak broadening and kernel average misorientation (KAM) parameter obtained by X-ray diffraction (XRD) and electron backscatter diffraction (EBSD), respectively, indicated a higher work hardening of austenite. Strain-induced martensite was not detected within this strain range by using X-ray diffraction and DC-magnetisation measurements. Two particular rolling thickness reductions were chosen for recrystallisation studies; i.e., 43% and 64%. After annealing for 1 min, primary recrystallisation occurred in ferrite (42% of recrystallised grains for 43% cold rolling), whereas austenite only recovered. For a reduction of 64%, the recrystallised fraction of ferrite did not change significantly, while austenite reached a recrystallised fraction of 43%. Full recrystallisation is noticed after annealing for 3 min for both conditions resulting in a bamboo-like grain structure
Establishing a conceptual model for residential development in New Zealand
No full textThere is growing concern among planners, policymakers, regulators, urban economists, and the general public that the contemporary housing market is failing to either provide an adequate supply of affordable housing. Mainstream thought attributes the ‘housing crisis’ primarily to the restriction of new housing supply by the planning system, creating an impetus to deregulate and liberalise urban land use through programmes of mass upzoning like the Auckland Unitary Plan. However, current models of urban land use change often ignore the way that diversity in developer behaviour and decision-making may affect development and land use outcomes. Significant features of this developer diversity in a New Zealand context include the strong and growing role of Māori in development and the importance of small homeowners and investors.
There is also growing concern that contemporary housing development does not adequately account for natural hazard risk and the future impacts of climate change. There is a lack of research investigating how developers react to natural hazard risks, mapping, and policy settings.
To remedy this weakness in the literature, this research identified and analysed diversity in the behaviour and decision-making of housing developers in New Zealand when deciding whether to purchase, develop, and/or sell sites. Special attention was given to sites subject to significant natural hazard risk(s) and the impact of policy interventions intended to control or manage development in at-risk areas. This was achieved through a review of the existing conceptual models of development and typologies of developers in the literature and a series of surveys and interviews with diverse developers throughout New Zealand. It outlines key conceptual features of the housing sector in New Zealand and proposes a new typology of housing developers that is specific to this context.
Key findings include the significant diversity that exists between developer types in the prioritisation of key variables and values that determine whether they choose to invest in an at-risk site; diversity of reactions to natural hazard risks and disparities in the efficacy of common risk communication tools between regions; and the vital role of the insurance sector in determining future land use change patterns and natural hazard risk exposure.
This research reveals the importance of a detailed and nuanced understanding of diverse developer behaviour and decision-making for future policymaking land use change modelling. It also highlights regional and local disparities in developer responses to current natural hazard mapping projects and the vital role of the insurance sector in determining future land use change patterns and natural hazard risk exposure by influencing in the site selection and development behaviour of housing developers
Using undrained cyclic triaxial tests to examine liquefaction resistance of historically liquefied pumiceous volcanic-ash soil materials and back-estimate prehistoric earthquakes.
No full textBack-analysis of ground motion characteristics, such as earthquake magnitude and peak ground accelerations, in paleoliquefaction studies are most commonly based on empirical CPT- and/or SPT-based correlations that estimate the liquefaction resistance of soil materials of relevance. Laboratory triaxial cyclic tests have not been explored for this purpose to date. Our study investigates the liquefaction resistance of three different beds (with differing grain-size distributions and pumice content) of a single rhyolitic (high-silica) volcanic-ash layer, referred to as Mamaku tephra, that was deposited ~8000 calendar years ago and preserved in lake sediments in multiple extant lakes in the Hamilton lowlands, North Island, New Zealand.
Paleoliquefaction features observed in the silty and sandy beds of the Mamaku tephra indicate seismic activity in the past. With our main aim being to back-analyse potential prehistoric earthquakes that might have caused the paleoliquefaction features in Mamaku tephra (and other lacustrine tephras), the following steps were taken:
(1) the liquefaction resistance of the three Mamaku tephra beds with different grain sizes and pumice contents from one site (Lake Areare, northern Hamilton lowlands) was investigated using undrained cyclic triaxial testing;
(2) a framework extending the laboratory liquefaction resistance results of the tested Mamaku beds at Lake Areare to other Mamaku tephra deposits in the lake sediments across the lowlands was proposed; and
(3) the equivalent peak ground acceleration and earthquake magnitude that would have caused liquefaction of all the lacustrine Mamaku tephra deposits across the lowlands (in 13 lakes) were estimated using available empirical correlation methods. A discussion about the limitations of the proposed framework alongside the qualitative implications on the results is also provided. It was found that the Mamaku tephra deposits are very vulnerable to liquefaction and require very low triggering peak ground acceleration to liquefy, i.e., amax in the range between 0.02 and 0.08 g through the range of magnitudes, M = 5–8.5
Global perspectives on open banking: Regulatory impacts and market response
No full textThis study investigates the adoption of open banking across several diverse global jurisdictions, focusing specifically on regulatory and market implications. Employing a comparative analysis, we examine the dual nature of open banking as both a regulatory framework and a technological innovation, exploring how different regulatory approaches shape its implementation and market reception. Results indicate significant variation in market responses to open banking announcements, presenting evidence of the underlying factors driving these disparities, such as the role of regulatory environments, technological infrastructures, and bank size in shaping market reactions
Applying the perceived creepiness of technology scale to social robots
No full textDesigning positive robot experiences requires an understanding of users' perceptions and meeting their needs in an ethical manner. However, despite best intentions, users have strong positive or negative reactions to robots, either finding them ''cute'' or ''creepy''. The Perceived Creepiness of Technology Scale (PCTS) was designed for evaluating how creepy a technology appears to a user on first encounter. In this paper we applied the PCTS to a cross-section of social robots to measure their perceived creepiness and evaluate the strengths and weaknesses of PCTS when applied in a Human-Robot Interaction (HRI) context. We demonstrate that while a robot may not be perceived as creepy initially, it can have underlying unethical practices inherent in its design which is not well captured by the PCTS. This emphasises the need for better HRI practices to ensure creepiness is appropriately assessed in the social robot domain
Development of extrudable hydrogels based on carboxymethyl cellulose–gelatin complex coacervates
No full textThis study investigates the 3D extrusion printing of a carboxymethyl cellulose (CMC)–gelatin complex coacervate system. Various CMC–gelatin coacervate hydrogels were prepared and analyzed to achieve this goal. The impact of the CMC–gelatin ratio, pH, and total biopolymer concentration on coacervation formation and rheological properties was evaluated to characterize the printability of the samples. Turbidity results indicated that the molecular interactions between gelatin and CMC biopolymers are significantly pH-dependent, occurring within the range of pH 3.7 to pH 5.6 for the tested compositions. Confocal Laser Scanning Microscopy (CLSM) confirmed the presence of coacervates as spherical particles within the optimal coacervation range. Scanning electron microscopy micrographs supported the CLSM findings, revealing greater porosity within this optimal pH range. Rheological characterization demonstrated that all CMC–gelatin hydrogels exhibited pseudoplastic behavior, with an inverse correlation between increased coacervation and decreased shear viscosity. Additionally, the coacervates displayed lower tackiness compared to gelatin hydrogels, with the maximum tackiness normal force for various CMC–gelatin ratios ranging from 1 to 15 N, notably lower than the 29 N observed for gelatin hydrogels. Mixtures with CMC–gelatin ratios of 1:15 and 1:20 exhibited the best shear recovery behavior, maintaining higher strength after shear load. The maximum strength of the CMC–gelatin coacervate system was found at a biopolymer concentration of 6%. However, lower biopolymer content allowed for consistent extrusion. Importantly, all tested samples were successfully extruded at 22 ± 2 °C, with the 1:15 biopolymer ratio yielding the most consistent printed quality. Our research highlights the promise of the CMC–gelatin coacervate system for 3D printing applications, particularly in areas that demand precise material deposition and adjustable properties