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[In Press] Smoke : enablers and barriers for sustainable engagement with local Aboriginal communities
No full textFor many years, activists in Early Childhood Education and Care (ECEC) have called for the sector to engage closely with Aboriginal and Torres Strait Islander families and communities. However, less is documented on how mainstream services might achieve authentic, sustained engagement at a local service level. This paper showcases educators who connect with local Aboriginal community members/Elders as a central plank of their ECEC practice. In sharing their account, we examine what engagement looks like and what makes it possible. We have used Indigenous methodologies and the Theory of Practice Architecture (TPA) as theoretical lenses for exploring the policy, and organisational arrangements that sustained their engagement practices. We discuss the theoretical and practical implications of the research
Dominance of particulate organic carbon in top mineral soils in cold regions
No full textThe largest stocks of soil organic carbon can be found in cold regions such as Arctic, subarctic and alpine biomes, which are warming faster than the global average. Discriminating between particulate and mineral-associated organic carbon can constrain the uncertainty of projected changes in global soil organic carbon stocks. Yet carbon fractions are not considered when assessing the contribution of cold regions to land carbon–climate feedbacks. Here we synthesize field paired observations of particulate and mineral-associated organic carbon in the mineral layer, along with experimental warming data, to investigate whether the particulate fraction dominates in cold regions and whether this relates to higher soil organic carbon losses with warming than in other (milder) biomes. We show that soil organic carbon in the first 30 cm of mineral soil is dominated or co-dominated by particulate carbon in both permafrost and non-permafrost soils, and in Arctic and alpine ecosystems but not in subarctic environments. Our findings indicate that soil organic carbon is most vulnerable to warming in cold regions compared with milder biomes, with this vulnerability mediated by higher warming-induced losses of particulate carbon. The massive soil carbon accumulation in cold regions appears distributed predominantly in the more vulnerable particulate fraction rather than in the more persistent mineral-associated fraction, supporting the likelihood of a strong, positive land carbon–climate feedback
Feasibility study of expanded clay aggregate lightweight concrete for nonstructural applications
No full textIn nonstructural infill panels, common materials like expanded polystyrene panels face fire susceptibility, autoclaved aerated concrete (AAC) incurs high production costs, and traditional bricks come with a significant carbon footprint and weight. So, there is a requirement for infill panels that are not just resilient and lightweight but sustainable as well. This study seeks to address these issues by introducing sustainable and lightweight expanded clay aggregate (ECA) in concrete. Firstly, eight ECA mix designs were prepared by integrating fly ash and kerosene with clay, and ECA with a bulk density of 0.59 g/cm³ and compressive strength of up to 1.73 MPa were prepared. The lightest ECA mix was then chosen to explore their use in lightweight aggregate concrete (LWAC) along with fly ash as a secondary cementitious material. The resulting LWAC had a minimum density of 1,050 kg/m³ and a compressive strength of 6.8 MPa, fulfilling the standard requirements of a minimum of 3.5 MPa for nonstructural concrete
Young people's experiences of the Northern Rivers 2017 flood and its effects on their mental health
No full textObjective: To explore young people's (YP) experiences of catastrophic flooding in the Northern Rivers area of northern NSW in 2017 and its effect on their mental health. Design: Content analysis of free-text survey responses (written responses to open questions, rather than selecting a response option). Setting: Northern Rivers NSW. Participants: YP aged 16–25 years who were Northern Rivers residents at the time of the 2017 flood. Results: YP found their flood experience to be novel and challenging. They expressed worry, distress, anxiety, and worsened pre-existing mental health issues as a result of the flood. YP reported a number of primary stressors (inadequate preparedness, warning and support during the flood) and secondary stressors (loss/damage of property and possessions, financial strain and disruptions to daily life) which potentially contributed to poor mental health. Some YP reported positive outcomes from their flood experience, notably increased community connectedness and personal resilience. However, they also expressed concern for the future, particularly potential reoccurrence of extreme floods as well as climate change. YP conveyed a desire for better community involvement to improve preparedness for future floods and a clear motivation to take action on climate change. Conclusion: The flood was a challenging experience for YP which was commonly described as negatively affecting their mental health. Understanding what YP view as significant events or issues arising from their personal flood experience may help target support mechanisms and services to maintain their mental. More focus on community-based initiatives to improve disaster preparedness can support mental health in YP
Productive disruptions : supporting diversity and anti-racism in the workplace through multi-level organisational strategies
No full textRacism in the workplace occurs at both the interpersonal and institutional level in terms of prejudiced attitudes and behaviours and avoidable and unfair differences in hiring, retention and opportunities for training and promotion. Many organisations have stated commitments to workforce diversity; however, work-related racism remains the most common forms of reported discrimination. Rather, efforts to increase workforce diversity will fail in the absence of measures to address discriminatory attitudes, behaviours, practices and cultures. Current approaches also lack strategic development, including knowledge of how to implement workforce diversity and anti-racism strategies at multiple organisational levels. Specifically, there is less understanding of measures to support structural level change. This article aims to advance both theoretical and empirical understanding of racism and anti-discrimination in the workplace. We do this by presenting a multi-level framework for understanding and addressing workplace racism. We also study the implementation of a meso-level workplace diversity and anti-discrimination assessment within two local government organisations in Australia. Findings revealed the importance of implementing strategies across multiple organisational levels and establishing accountability for commitments to diversity and anti-racism practice. Despite its structural and universal drives, we argue that racism can be disrupted through the presence of diversity in the workplace and anti-racism intervention
Predicting the residual compressive strength of concrete exposed to elevated temperatures using interpretable machine learning
No full textThe accurate prediction of residual compressive strength (RCS) of concrete plays a critical role in assessing concrete con- structions’ safety and structural integrity following exposure to elevated temperatures. Existing ensemble models exhibit RCS prediction capabilities, yet they are constrained by their opaque nature. This research endeavors to develop an intelligible model for RCS by employ- ing five ensemble machine-learning models, namely, random forest (RF), adaptive boosting (AdaBoost), gradient boosting (GBoost), light gradient boosting (LGBoost), and extreme gradient boosting (XGBoost), and integrating Shapley additive explanations (SHAP) to as- certain the precise importance of each input variable in forecasting the RCS of concrete under elevated temperature conditions. The input variables encompass concrete type, compressive strength, aggregate type, water-cement ratio, heating type, heating rate, maximum core temperature, and cooling type. Model performance is appraised using established performance metrics such as mean absolute error (MAE), mean squared error (MSE), root-mean squared error (RMSE), and coefficient of determination (R2). The analytical results exhibit the efficacy of employing machine-learning models in accurately predicting the RCS of concrete under elevated temperature conditions. Among the implemented models, XGBoost demonstrated the highest performance, yielding an R2 value of 0.876, closely trailed by the LGBoost model at 0.871. The SHAP analysis elucidates the crucial role of core temperature, water-cement ratio, heating rate, and compressive strength in determining the RCS of concrete
Biomedical data analytics and visualization : a methodological framework
No full textBiomedical data analytics have become a major decision-making aid for the diagnosis and treatment of diseases. Computational and visual analytics enable effective exploration and making sense of large and complex data through the deployment of appropriate machine learning and statistical analytics methods, meaningful visualisation, and human–information interaction. This chapter serves as a tutorial that provides guidelines, discussion, and reviews on methods and technologies that have been used for biomedical data analytics. We discuss the major processes of biomedical data analytics that are required to produce effective analytical outcomes. The chapter covers comprehensive discussions on computational analytics strategies, including feature selection, feature extraction, and clustering. Methods and several aspects of visual analytics and interactive visualisation in biomedical data analytics are also thoroughly explained and illustrated, including scatter plots, heat maps, parallel coordinates, network and graph visualisations, tailored visualisation, and visualisation in emerging technologies (such as virtual reality and augmented reality), as well as the human aspect of visualisation
Influence of amino-functionalized carbon nanotubes and acrylic triblock copolymer on lap shear and butt joint strength of high viscosity epoxy at room and elevated temperatures
No full textThis study investigates the effectiveness of incorporating different amino-functionalized carbon nanotubes (CNTs) and acrylic triblock copolymer (BCP) into an aerospace-grade relatively high-viscosity epoxy (EA9396) resin to enhance the lap shear and tensile butt-joint strength at room and elevated temperatures (90 ◦C). To address the common issue of nanoparticle agglomeration in epoxy resin, which is exacerbated by its relatively high viscosity, a novel processing method was developed. This method involves ozone oxidation followed by functionalization with either polyethyleneimine (P + oz-CNTs) or a polyamine hardener (H + oz-CNTs). The functionalization not only ensures uniform dispersion of carbon nanotubes (CNTs) but also enhances their chemical reactivity with both the epoxy and block copolymer (BCP) matrix. The bonding performance of the epoxy, incorporating functionalized CNTs and BCP, was evaluated using single lap shear and tensile butt-joint tests. The results emphasize the substantial enhancement of both lap shear and butt-joint strength in the BCP-modified epoxy with the incorporation of functionalized CNTs (P + oz-CNTs and H + oz-CNTs), evident at both room temperature and 90 ◦C. At ambient conditions, the lap shear strength of the nanocomposite adhesives (P + oz-CNT + BCP EA9396 and H + oz-CNT + BCP/EA9396) exhibited significant improvements of 40 % and 48% respectively. At 90 ◦C, both formulations demonstrated a 20 % increase in lap shear strength. Furthermore, considerable advancements were observed in butt joint strength, with enhancements of 22 % (P + oz-CNT + BCP/EA9396) and 28 % (H + oz-CNT + BCP EA9396) at room temperature. Importantly, compared to the unmodified epoxy, the butt joint strength displayed even more remarkable improvements of 49 % (P + oz-CNT + BCP/EA9396) and 42 % (H + oz-CNT + BCP/EA9396) at 90 ◦C. The analysis of fracture studies showed that introducing amine functionalization resulted in a more consistent dispersion of CNTs and enhanced the ability of the BCP/EA9396 to undergo plastic deformation. The study further demonstrates that functionalization with PEI and amine hardener reduces CNT pull-out, which enhances energy dissipation mechanisms and increases lap shear and butt joint strengths
Green engineered cementitious composites with enhanced tensile and flexural properties at elevated temperatures
No full textThis study provides new insights in the design of green hybrid polyethylene (PE)-steel fibre reinforced high strength engineered cementitious composite (HSECC) with superior tensile and flexural strength at both ambient and elevated temperatures. Blends of high volume of ground granulated blast furnace slag (GGBFS), dolomite powder and fly ash were utilized to achieve a 60 % cement replacement for the HSECC mixes. These mixes were then exposed to 20–600 °C and a total of 210 specimens were tested to assess their residual tensile stress–strain behaviour, flexural load–displacement response, and toughness. Results indicate that high volume of GGBFS can be very effective in limiting the surface damage and retaining high strength at elevated temperatures. A combination of 1.5 % PE-0.75 % steel with quaternary blend of GGBFS, dolomite and fly ash demonstrated at least 60 % and 40 % retention in tensile and flexural strength at 600 °C, respectively. This was significantly better than the strength of the traditional control silica fume mix considered in this study as well as results reported in many previous literatures on HSECC. Microstructural examination was further conducted to understand the mechanism of fibre deterioration and justify the resulting change in pseudo-hardening behaviour with temperature rise. Findings obtained in this study clearly demonstrated the effectiveness of PE-steel fibre hybridisation at elevated temperature and confirmed that with right binder selection, superior tensile and flexural performance can be achieved even with a very high cement replacement level
The performance of renewable energy infrastructure
No full textPurpose: Renewable energy infrastructure is an important asset class in the context of reducing global carbon emissions going forward. This includes solar power, wind farms, hydro, battery storage and hydrogen. This paper examines the risk-adjusted performance and diversification benefits of listed renewable energy infrastructure globally over Q1:2009–Q4:2022 to examine the role of renewable energy infrastructure in a global infrastructure portfolio and in a global mixed-asset portfolio. The performance of renewable energy infrastructure is compared with the other major infrastructure sectors and other major asset classes. The strategic investment implications for institutional investors and renewable energy infrastructure in their portfolios going forward are also highlighted. This includes identifying effective pathways for renewable energy infrastructure exposure by institutional investors. Design/methodology/approach: Using quarterly total returns, the risk-adjusted performance and portfolio diversification benefits of global listed renewable energy infrastructure over Q1:2009–Q4:2022 is assessed. Asset allocation diagrams are used to assess the role of renewable energy infrastructure in a global infrastructure portfolio and in a global mixed-asset portfolio. Findings: Listed renewable energy infrastructure was seen to underperform the other infrastructure sectors and other major asset classes over 2009–2022. While delivering portfolio diversification benefits, no renewable energy infrastructure was seen in the optimal infrastructure portfolio or mixed-asset portfolio. More impressive performance characteristics were seen by nonlisted infrastructure funds over this period. Practical reasons for these results are provided as well as effective pathways going forward are identified for the fuller inclusion of renewable energy infrastructure in institutional investor portfolios. Practical implications: Institutional investors have an important role in supporting reduced global carbon emissions via their investment mandates and asset allocations. Renewable energy infrastructure will be a key asset to assist in the delivery of this important agenda for a greener economy and addressing global warming. Based on this performance analysis, effective pathways are identified for institutional investors of different size assets under management (AUM) to access renewable energy infrastructure. This will see institutional investors embracing critical investment issues as well as environmental and social issues in their investment strategies going forward. Originality/value: This paper is the first published empirical research analysis on the performance of renewable energy infrastructure at a global level. This research enables empirically validated, more informed and practical decision-making by institutional investors in the renewable energy infrastructure space. The ultimate aim of this paper is to articulate the potential strategic role of renewable energy infrastructure as an important infrastructure sector in the institutional real asset investment space and to identify effective pathways to achieve this renewable energy infrastructure exposure, as institutional investors focus on the strategic issues in reducing global carbon emissions in the context of increased global warming