Development of Radar and Optical Tracking of Near-Earth Asteroids at the University of Tasmania

We detail the use of the University of Tasmania’s (UTAS) optical and radio telescopes to conduct observations of near-Earth asteroids from 2021 to 2024. The Canberra Deep Space Communication Complex transmitted a radio signal at 7159.45 MHz, with the radar echo detected by the UTAS radio telescopes. The method of accounting for the Doppler shift between the stations and the near-Earth object is described so that others can implement a similar program. We present our results, with confirmed detections of 1994 PC1 and 2003 UC20 asteroids using the Hobart and Katherine 12-m antennas, demonstrating the feasibility of using small radio telescopes for these observations. Additionally, the recently upgraded Ceduna 30 m antenna was used to detect 2024 MK. Data collected from other observatories, such as Tidbinbilla, as well as the UTAS radar tracking of the moon are also presented in the context of demonstrating the means of applying these Doppler corrections and the accuracy of each method. Optical observations conducted in this period are also detailed as they complement radar observations and aid in refining the orbit parameters

Developing and validating a positive mental health scale for the global south construction industry: the construction industry positive mental health inventory (CI-PMHI)

Purpose: Promoting positive mental health is increasingly being encouraged as the focus of research and policies on the mental health of construction personnel. Most measures of mental health, however, typically use negative indicators such as depression and anxiety and are not specifically developed for the construction workforce, especially those with a Global South background. These limitations have made it challenging to measure construction personnel’s positive mental health. The purpose of this study was, therefore, to develop a scale for measuring the positive mental health of construction personnel with a Global South background. Design/methodology/approach: Guided by Keyes’ two-continua model of mental health, the study objectives were addressed through a mixed-methods study using the case of Ghana. Qualitative data collected from eight key stakeholder groups using 16 interviews and two rounds of focus group discussions were analysed thematically. Quantitative data were obtained through a survey of 425 construction personnel and analysed using confirmatory factor analysis and correlation analysis. Findings: Thematic analysis revealed a four-dimensional structure of positive mental health, namely, emotional, psychological, social and spiritual. Confirmatory factor analysis and correlation analysis of the results indicated good instrument validity and reliability. Originality/value: Existing measures of positive mental health are based on a three-dimensional model, i.e. emotional, social and psychological well-being. By including spiritual well-being, this study proposes a four-dimensional measurement model as a more comprehensive and promising measure to use in surveys of positive mental health among the construction workforce, especially those with a Global South background, and to develop suitable interventions for them

Soft Conductive Stitching of Carbon Fibre Reinforced Composites for Electrical Conductivity Enhancement

Carbon fibre reinforced polymer (CFRP) has become dominant in aerospace structural materials due to its lightweight and high specific strength. However, its low electrical conductivity, particularly in the through-thickness direction, limits its application in areas requiring conductive structures, such as lightning strike protection (LSP), electromagnetic interference (EMI) shielding, and structural health monitoring. Stitching has emerged as a low-cost and effective method to enhance the interlaminar fracture toughness and can be used to increase electrical conductivity of the composites by incorporating conductive materials, thereby promoting the multifunctionality of the structural composites. Nonetheless, the primary concern is the potential reduction in the in-plane mechanical strength. Additionally, comprehensive studies investigating both the electrical and mechanical performance of stitched composites remain limited. This work aims to address these gaps by conducting an in-depth study using soft conductive yarns to enhance electrical conductivity while maintaining sufficient mechanical strength. The study first focused on investigating the effects of stitching parameters, including yarn type and stitch density on electrical and mechanical properties. One of the silver-coated low-stiffness yarns significantly improved electrical conductivity and mode I interlaminar fracture toughness. The study demonstrated that a marginal reduction of tensile strength can be achieved by adjusting the stitching density. Hence, both electrical and mechanical can be tailored to meet specific requirements. The effects of stitch parameters were further investigated the electrical and mechanical properties by implementing the silver-coated yarn stitching in a grid pattern due to the potential to provide uniform deformation distribution and reduce anisotropy of in-plane properties. High-voltage impulse testing was also conducted to evaluate the effectiveness of stitched composites for lightning strike protection (LSP) applications. At the highest stitch density (smallest grid size), the stitched composites offered similar protection under high-voltage condition to commercial metallic mesh materials. However, the specimen with the smallest grid size exhibited the greatest reduction in in-plane mechanical properties compared to baseline composites. To further enhance electrical conductivity while retaining mechanical strength, surface modification was integrated with lower stitch-density composites. In this study, a thin silver-coated carbon fibre veil was combined with stitching to provide more conductive paths on the surface. After high-voltage testing, integrating a conductive veil with stitching showed residual flexural strength comparable to metallic mesh composites. This approach allowed the stitched composites to achieve high conductivity and fracture toughness while retaining sufficient mechanical strength for LSP application without the necessity of very small grid stitching. This work provides new contributions on the impact of stitching parameters using soft conductive yarns on the electrical and mechanical performance of the composites, which is essential for developing structural composite design for applications where current dissipation is significant. Additionally, critical stitch parameters for protecting composites under the high-voltage conditions were obtained. A novel approach using an integrated silver-carbon conductive layer together with the conductive stitching revealed that the primary lightning strike protection mechanism was attributed to current dissipation from the strikes’ impact location to the conductive yarns. This developed design of the through-thickness reinforcement method offers the advantage over conventional lightning strike protection materials by improving delamination resistance, reducing the potential of galvanic corrosion associated with traditional copper materials, and highlighting the multifunctionality of the stitched composites for electrical applications. The developed composites have the potential for lightning strike protection while maintaining sufficient structural capability for aerospace and automotive applications

Optical Nanopore Sensors for Quantitative Analysis of Dilute Analytes

Nanopore sensors are a promising class of devices for single-molecule quantification of biomarkers. They have been successfully used to detect small molecules, nucleic acids and proteins. However, there are still some challenges that limit nanopore sensors in practical applications, for example, long response time and lack of specificity in complex biological media. The nanopore blockade concept has been developed to overcome these challenges. The specificity was improved by using antibodies to label magnetic nanoparticles and nanopore surface. The particles after incubating with biological sample to capture the target were driven to the nanopore surface using an external magnetic field to reduce the wait time. When the target was present in solution, an immunosandwich was formed. Non-specific blockade events were distinguished from specific blockade events based on the ability to pull the particles out of the pore via the application of magnetic field. Counting the number of blocking and unblocking events provided selectivity to the target. Unfortunately, this assay only archived semi-quantitative at best due to a limited number of pores (typically 9) since the electrical noise increased with a larger number of pores. To enable the nanopore blockade sensor to be truly quantitative, an optical readout technique was used rather than the traditional ionic current readout method. Using fluorescent nanoparticles and wide-field microscope allowed to monitor hundreds of nanopores on a single array simultaneously, making this assay truly quantitative. Furthermore, modifying the nanopore surface with an aptamer instead of antibody showed a better benefit in terms of detecting not only single target but also multiple proteins at the same time. Utilizing an aptamer unlocked the ability to bind to multiple targets and different colours of fluorescent particles functionalized with different antibodies targeting to different proteins, enabled this optical nanopore sensor to be able to quantify multiple targets in rapid time. In summary, this dissertation provides the fundamental and primarily results in using nanopore assays to quantify not only a single biomarker but also multiple ones in rapid time. This is an important step towards the use of nanopore blockade sensors for the ultra-sensitive detection of multiple biomarkers in practical applications

“It's not just running the test”: Operator experiences of implementing a decentralised hepatitis C point-of-care testing program in Australia

Background: The decentralisation of hepatitis C virus (HCV) point-of-care testing is a core part of Australia's strategy to meet WHO elimination targets. However, little is known about the experiences of providers implementing these interventions and thus what is needed to improve integration. The study aim was to understand operator experiences, including the challenges and enablers, of implementing point-of-care testing as part of a National Point-of-Care Testing Program. Methods: Providers who were enrolled in the National Program and qualified to perform point-of-care testing were invited to participate in semi-structured qualitative interviews between April and August 2023. Data were analysed according to iterative categorisation and themes were organised according to Service delivery, Resources, and Governance—elements of the Health Systems Dynamics Framework. Results: Of the 31 participants, most were from New South Wales (n = 17), were practicing clinicians (n = 18), worked in outpatient or community health clinics (n = 21), and had no previous experience using a molecular point-of-care testing device (n = 24). Many participants struggled to deliver HCV testing and treatment according to national HCV management guidelines. Some participants avoided using the point-of-care testing device altogether. Others found it challenging to manage the administrative load of delivering the National Program, including planning outreach and following-up clients. These challenges were exacerbated by workforce shortages, difficult-to-navigate IT systems, and a lack of specific implementation advice from Program leadership. Conclusions: This study illustrates several challenges to and enablers of adopting a decentralised HCV point-of-care testing program, highlighting the need to further explore what providers require to effectively implement these interventions

Flow Battery Stack and System Design Modelling for Energy Storage

Flow batteries have been rapidly developing for large-scale energy storage applications due to their safety, low cost and ability to decouple energy and power. However, the high cost of large-scale experimental research has been a major hurdle in this development. As a result, modelling the stack and system is a more cost-effective approach for battery designs suitable for manufacturing real commercial-size battery stacks. This thesis aims to develop hydraulic, electrochemical and coupled stack and system models for flow batteries. The models cover two types of batteries: the vanadium flow battery (VFB), which is the most well-established flow battery and has been in commercial use for a few years, and aqueous organic flow batteries (AOFB), which have garnered increased research interest due to their potentially lower costs and customisable molecular structures. A dynamic model has been developed in MATLAB to rapidly simulate the stack and system performance over multiple cycles. The models can predict efficiencies, capacity fade and concentration variations for long-term operation. The results demonstrate that the capacity fade of the AOFB is predominantly impacted by ion crossover and active species degradation. The capacity fade can be mitigated by the accumulation of diffused ions across the membrane, which effectively suppresses further ion crossover. It is also crucial to consider the pressure balance when dealing with varying densities and viscosities of the anolyte and catholyte at different States of Charge. While the dynamic model provides rapid analysis of the stack and system over time, a 3D hydraulic stack model has been developed in COMSOL to demonstrate detailed velocity and pressure distributions in flow batteries at steady states. The model incorporates a parameterised geometry for the battery stack, allowing input parameters to be varied for different chemistries and stack designs. Simulations have shown that side gaps and porosity variations in the graphite felt can lead to preferential flow in low-resistance areas, resulting in insufficient flow rates in the active cell areas. Proposed countermeasures, including adjusting channel locations and applying dimples to the flow frame, have shown improved performance. The developed models provide valuable insights for the design of large-scale flow battery systems

It is never too late to stop smoking. Applying working estimates of smoking cessation on five-year overall survival gains after a cancer diagnosis

Background: Detailed data on five-year overall survival (5Y-OS) in relation to smoking cessation after a cancer diagnosis are sparse. Implementation of smoking cessation in cancer treatment centres is also sub-optimal. The aim is to provide working, numeric estimates of 5Y-OS outcomes in relation to quitting smoking to help inform patients with cancer. Methods: 5Y-OS data and hazard ratios (HR) from a moderately sized cohort study from Japan were used to derive survival benefits on Australian cancer survival scenarios ranging from 10 % to 90 % 5Y survival, using standard epidemiological formulas comparing survival in those who recently quit around the time of their cancer diagnosis in comparison to those who continued to smoke. Results: In a scenario of a cancer type with 90 % 5 y survival e.g. breast, prostate cancer, or melanoma, quitting smoking shows a gain in 5Y-OS of 10 %, and a gain in median survival of 2.1 years. In a scenario of 20 % 5 y survival (e.g. lung, liver, brain, or oesophageal cancer) recent quitting shows a 5Y-OS gain of 2 %, and a median survival gain of three months. Conclusion: The greater the survival at presentation, the greater the gain by quitting smoking. Future research should aim to produce estimates based on real-world data

Exercise adherence is associated with improvements in pain intensity and functional limitations in adults with chronic non-specific low back pain: a secondary analysis of a Cochrane review

Question: What is the association between exercise adherence and the effects of exercise on pain intensity and functional limitations in adults with chronic non-specific low back pain (CNSLBP)? Design: Systematic review with meta-analysis. Participants: Adults with CNSLBP. Intervention: Randomised controlled trials of exercise compared with no exercise (eg, usual care, placebo/sham or another conservative treatment). Adherence to exercise must have been reported. Outcome measures: Pain intensity and functional limitations. Results: This study included 46 trials with 56 exercise groups. High exercise adherence (80 to 100%) was associated with reduced pain intensity (0 to 100 scale) (MD –14.32, 95% CI –18.61 to –10.03, low certainty) and functional limitations (0 to 100 scale) (MD –8.08, 95% CI –10.68 to –5.49, low certainty). Moderate exercise adherence (60 to 79%) was not associated with reduced pain intensity (MD –4.53, 95% CI –9.39 to 0.34, very low certainty) or functional limitations (MD –2.75, 95% CI –6.00 to 0.51, very low certainty). Low exercise adherence (< 59%) was associated with reduced pain intensity (MD –5.33, 95% CI –10.00 to –0.66, low certainty) and functional limitations (MD –4.43, 95% CI –7.14 to –1.72, moderate certainty). Compared with low adherence, additional differences in outcomes for moderate and high adherence were mostly negligible. Conclusion: Higher exercise adherence is associated with larger improvements in clinical outcomes in adults with CNSLBP, although overall differences are small compared with lower adherence. Other factors besides adherence between the trials and exercise programs could explain these results. Further research is needed to determine the causal effect of exercise adherence on outcomes in adults with CNSLBP. Registration: PROSPERO CRD42023447355 and Open Science Framework https://osf.io/7p6dw/