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Regional Railway Dwell Time Management – New Methods and Insights
No full textDwell time, which is the period a train remains stationary at a station platform to enable passenger boarding and alighting, is a deceptively simple yet critically influential factor in railway operations. This thesis presents a comprehensive investigation into dwell time dynamics within regional railway systems, with a particular focus on the operational environment of the regional railway of Victoria, Australia. Despite the established importance of dwell time in metropolitan railway planning, regional railway networks which are generally characterised by lower service frequencies, conductor-led dispatch protocols (that is the process a train conductor must complete before the driver can start closing the doors), heterogeneous passenger markets, and infrastructural constraints, remain significantly under-examined in academic and practical discourse. This thesis seeks to address this gap by offering theoretical insight, empirical evidence, and an applied modelling framework tailored to the unique demands of regional railways.The research begins by exploring the historical, technological, and operational evolution of railways, establishing the critical role of dwell time within broader transport planning and timetable robustness. Rail networks, particularly in high-growth regional corridors, must now contend with increasingly complex interdependencies between infrastructure capacity, service reliability, and shifting passenger behaviour. As regional railways become central to sustainable transport agendas, particularly in light of post-pandemic decentralisation trends and lifestyle-driven migration to peri-urban areas, effective dwell time management emerges as a key lever for enhancing performance and passenger satisfaction.Through a comprehensive literature review (see Chapter Three), the thesis identifies major conceptual and methodological gaps in existing dwell time modelling practices. The field is currently fragmented across three primary methodological streams that are statistical regression, simulation-based models, and emerging machine learning techniques. These approaches, however, predominantly focus on high-frequency metropolitan networks whilst mostly neglect the distinctive operational realities of regional railways (such as rollingstock and operational procedures). To bridge the divide between academic modelling and operational relevance, the thesis proposes a novel decision-support framework that guides rail agencies in selecting and implementing appropriate dwell time models. This framework aligns modelling strategy with six contextual dimensions (see Chapter Four). By doing so, it provides a pragmatic tool to translate theoretical insights into operational practice, especially for resource-constrained regional operators (i.e. operators that may not have the relevant personnel or not have the appropriate information systems infrastructure).A major empirical component of the study involves video-based analysis of passenger behaviour and train operations at two Victorian regional railway stations of Cobblebank and Rockbank (see Chapter Two). This method yielded high-resolution data from nearly 400 services and revealed significant behavioural and procedural insights. Notably, passengers tended to cluster around a limited number of train doors, leading to localised congestion and uneven platform utilisation. Platform design features such as shelter placement and access points strongly influenced passenger distribution, further affecting boarding and alighting times.A particularly novel discovery was the “blinded phenomenon,” wherein conductors lacked sufficient visibility to confirm passenger movement completion during peak periods (see Chapter Five). This operational bottleneck, absent in more automated metro environments (due to measures to assist the driver such as a live CCTV console on the platform), underscores the need for both technological enhancements (e.g. CCTV coverage, AI-assisted dispatch tools) and revised platform design to mitigate unintentional delays. These findings highlight some key differences to metropolitan railway operations and the need for context-specific dwell time evaluations.In response, the thesis evaluates the performance of five widely cited statistical dwell time models, originally developed for metropolitan/suburban networks, against real-world regional rail data (see Chapter Six). The findings consistently demonstrate that these models underpredict actual dwell times due to failure to account for operational components like door interlock durations, conductor interventions, and platform visibility constraints. The legacy models’ assumptions based on metropolitan or suburban operational conditions proved incompatible with regional realities.To address these limitations, this thesis develops the Regional Dwell Time (RDT) Model (see Chapter Seven). This hybrid model is composed of a linear regression model calibrated on empirical data that estimates passenger flow time through the peak door, with the addition of operational constants that better reflect the operation realities of a regional railway. The RDT Model integrates boarding and alighting counts at the peak-use door with additive constants that represent key operational processes. It achieves significantly higher predictive accuracy than legacy models whilst maintaining simplicity, transparency, and practical intuition. Its structure enables local recalibration and aligns with agencies’ typical resource capacities, making it suitable for integration into planning workflows, scheduling systems, and performance forecasting tools.The thesis advances the theoretical landscape of railway operations by redefining dwell time as a hybrid construct shaped by both behavioural fluidity and fixed procedural anchors. It introduces the idea of a dwell time modelling lifecycle, encompassing development, deployment, feedback integration, and institutional readiness reframes dwell time modelling as a socio-technical rather than purely mathematical exercise. Methodologically, the study pioneers a scalable, video-based analytics framework for data-scarce environments, offering a viable alternative to smartcard (i.e. digital ticket/fare) or APC-dependent methods.The study's limitations which include its reliance on two station locations, absence of demographic data, and exclusion of real-time variables are acknowledged, and form the basis for future research priorities. These include expanding to interchange stations and termini, integrating real-time operational and crew data, and adopting more dynamic modelling approaches such as digital twins and machine learning-enhanced simulations. Furthermore, behavioural insights could be deepened through human factors research, including accessibility barriers and psychological drivers of boarding behaviour.Ultimately, this thesis offers a foundational contribution to the understanding and optimisation of dwell time in regional railways. It provides both a theoretical reframing of dwell time modelling and an operational tool that is ready for application. By shifting focus from high-density metros to underserved regional contexts, this research supports the development of smarter, more responsive, and equitable transport systems capable of meeting the evolving mobility demands of decentralised, post-pandemic societies.</p
Control measures for neglected tropical diseases: vaccine updates
No full textINTRODUCTION: Infectious diseases like neglected tropical diseases (NTDs) have seen a rapid surge in recent times, threatening public health. These diseases impose a significant global health burden, affecting individuals, particularly in tropical locations characterized by low-income populations. The comprehensive compilation of NTDs includes an array of bacterial, viral, and parasitic infections. The prioritization of 20-NTD action plans in 2020 was undertaken by the WHO to acknowledge their importance. Infections such as leishmaniasis, schistosomiasis, and human African trypanosomiasis exhibit high rates of mortality. This highlights the pressing need for collaborative initiatives aimed at addressing these diseases and minimizing their detrimental impact on susceptible populations.
AREAS COVERED: The etiology, types of NTDs, and management strategies, particularly vaccinations are discussed. The limitations of the available vaccines and the scope of development of novel formulations are also covered.
EXPERT OPINION: The emergence of vaccines for NTDs poses significant challenges, mostly arising from the complex developmental phases of diverse diseases, inadequate resources for research, minimal involvement from the pharmaceutical industry, and the wide spectrum of infections, impeding vaccine development. Advancements in technology have improved vaccine quality, which could lead to the development of personalized vaccines tailored to individual susceptibility to specific NTD pathogens.</p
Beyond AI4DB: A Practical Exploration of Learned and Classical Techniques for Query Optimization in Database Systems
No full textModern database systems face growing performance challenges due to increasingly complex
data and the limitations of hand-crafted heuristics. The emerging field of AI for
Databases (AI4DB) investigates how machine learning techniques can be applied to core
DBMS components, such as indexing, cardinality estimation, and query optimization, to
improve adaptability, accuracy, and efficiency. While these approaches show significant
promise, their practical deployment often faces challenges such as integration overhead
and limited generalization. To address these limitations, this thesis explores a practical
spectrum of techniques, encompassing both learned and classical methods, that are designed
to operate effectively in realistic database settings and deliver robust performance.
First, we address the foundational task of data access by revisiting learned indexes
in the disk-resident setting. Through systematic evaluation, we show that state-of-the-art
in-memory learned indexes fail to outperform traditional B+-trees on disk due to I/O inefficiency,
costly structural modifications, and suboptimal storage layouts. To overcome
these limitations, we propose AULID, a fully on-disk updatable learned index that combines
learned models in inner nodes with B+-tree-style leaf nodes. This hybrid design
reduces tree height and lookup I/O while supporting efficient updates and scans, achieving
superior performance and storage efficiency across a wide range of workloads.
Second, we develop practical cardinality estimators tailored to complex data types
where traditional methods often fall short. For high-dimensional data, we introduce a
reference-based framework that estimates query cardinality using a small set of representative
reference objects. Within this framework, we propose two complementary methods:
one non-learning-based and one learning-based. For string data, we propose a classifier-based
estimator that reformulates the cardinality estimation task for LIKE queries as a classification problem. The method integrates a novel stacked filter-based architecture
with formal error guarantees, delivering accurate and efficient estimates while significantly
reducing construction overhead compared to existing approaches.
Third, we enhance the query optimizer’s plan selection process without modifying the
underlying optimizer. We propose a practical two-stage framework. In the first stage,
Plan Candidate Generation, we retrieve high-quality execution plans from a precomputed
pool using similarity-based search. In the second stage, Plan Ranking, we apply a list-wise
neural ranking model to select the most efficient plan from the candidate set. This approach
leverages plan reuse and contextualized ranking to improve end-to-end query performance
while preserving the compatibility and stability of existing optimization frameworks.
These contributions collectively demonstrate that practical performance improvements
can be achieved by thoughtfully applying both learned and classical techniques. By targeting
realistic deployment scenarios and emphasizing modularity, robustness, and efficiency,
this thesis offers actionable solutions that advance the practical frontiers of AI4DB.</p
Controllability in Complex Network Systems with Switching Topology
No full textControllability in complex network systems (CNSs) has attracted much attention due to their extensive applications such as power grids regulation, formation task of unmanned air vehicles and cooperative surveillance. These networks are often dynamically changing due to the complex environment in practice. Hence, the CNSs with switching topology are used to describe such circumstances. Although the existing research on the controllability of CNSs has been paid much attention by many researchers, there are still some further problems worth exploring. For example, the structural controllability of CNSs with periodic switching topology (CNSs-PST), the state controllability involving switching time sequence for CNSs-PST, and the application of controllability in fractional-order switching CNSs under the influence of delay are still not discussed. These problems are necessary and important in CNSs.
In this thesis, we will first investigate the relationship between structure controllability and state controllability, and then study the controllability in CNSs with switching topology from the following several topics.
The first part of this thesis is aimed to investigate the structural controllability in the CNSs-PST from two aspects. It should be noted that PST has been widely observed in both natural and engineered systems. For instance, in industrial automation or robotic systems, tasks may be periodically allocated, leading to periodic changes in the cooperative topology of automated devices. However, existing studies on CNSs-PST primarily focus on stability issues. To date, how the periodic switching mechanism affects the controllability of CNSs remains unclear, particularly in large-scale CNSs. In light of this, this part first addresses the structual controllability problem in complex network systems with strictly periodic switching topologies (CNSs-SPST), i.e., both the topology structures and edge weights undergo simultaneous periodic switching. We establish the structural controllability conditions based on some existing notions, such as temporal dilation, temporal walk, -walk theory. Then, we further address the structual controllability problem in complex network systems with generally periodic switching topologies (CNSs-GPST), i.e., the topology structures undergo periodic switching and edge weights may undergo non-periodic switching. A condition to judge structural controllability is obtained, which only requires to analyse the topology of the joint graph in a single period for CNSs-GPST. This part is pivotal as it systematically addresses the unexplored relationship between periodic switching mechanisms and structural controllability in CNSs, bridging a critical knowledge gap for both strict and general switching scenarios. Finally, several numerical examples are presented to validate the theoretical results.
The second part of this thesis develops new state controllability conditions for CNSs-PST with respect to dwell time. Firstly, a necessary and sufficient condition is proposed to determine how dwell times influence the state controllability by using the algebraic and geometric knowledge of matrix. Next, based on the obtained controllability condition, we further establish several state controllability criteria that will not be affected by dwell time for CNSs-PST under special constraints. This implies that the state controllability of CNSs-PST remains even when the dwell time changes. Compared with existing studies, the results in this section explore the intrinsic connection between dwell time and controllability of switched CNSs. This provides novel insights for stability analysis and controller design of such systems. Moreover, the investigated model serves as a fundamental framework. If practical factors such as time delays and impulsive effects are further incorporated, the proposed results can be extended to broader scenarios. Finally, several numerical examples are presented to confirm the theoretical results.
The third part of this thesis is to apply the controllability theory to fractional-order switched multi-agent systems with input delay. Due to the complexity of multi-agent working environment, the dynamic characteristics of some natural or engineering phenomena may not be described by integer order dynamical systems, but can only be explained by the cooperative behavior of intelligent individuals in fractional order dynamics. In light of this, the relevant controllability conditions are established for fractional-order switching multi-agent systems with input delay (FOSMASID) by resorting to the algebraic method. First, we obtain the solution representation of FOSMASID over every subinterval by using the Laplace transform and mathematical induction. Next, by introducing the Gramian matrices over every subinterval, we establish the controllability conditions without requiring all impulse-dependent matrices to be nonsingular. Furthermore, based on the relevant matrix theory, we further establish a controllability condition that is necessary and sufficient by introducing the form of a row of Gramian matrices. In the last, a numerical example with three subsystems is worked out to illustrate the theoretical results.</p
Development of Bioactive Compounds Enriched Malted Milk Powder by Incorporating Selected Germinated Cereals and Pulses
No full textAt present, people are seeking ready-to-eat food products which have optimum nutritional value as well as health benefits due to urbanisation, loss of traditional food culture, concern about personal health led by the busy lifestyle, and increase the risk of non-communicable diseases. Hence, the development of functional foods has become a trend that can improve human well-being. Cereals and pulses are considered as functional food ingredients of providing proteins, carbohydrates, dietary fibres, vitamins, minerals, and phytochemicals such as polyphenols and flavonoids. Though cereal and pulses provide nutritional value, antinutritional factors such as oxalate, phytates and saponins and protease inhibitors limit their nutritional quality and bioavailability of nutrients. Therefore, researchers applied various processes to improve nutritional quality of cereal and pulses such as dehulling, cooking, germination, soaking and fermentation. Among all processes, gemination can be used as an economical, environmentally friendly and effective way to enhance the nutritional value and functional properties of cereal and pulses. Germination alters seeds’ biochemical and physical properties and enhances bioactive compounds due to enzymatic action during germination. Germinated seeds are considered beneficial and superior to non-germinated seeds due to their increased antioxidant activity and nutritional value. Germination also improves digestibility, leads to the formation of new bioactive compounds, and helps mask unpleasant flavours and odours. Hence, germinated cereal and pulses can be used as a potential functional food ingredient rather than a raw type.
This study primarily aimed to develop a malted milk powder enriched with bioactive compounds from germinated cereals and pulses, intended as a grain- and dairy-based functional beverage. It also investigated the bioavailability and bioaccessibility of nutrients and bioactive compounds, with and without zinc fortification, using a simulated in vitro digestion model.
In the first stage of this research, the investigation of the optimum germination condition which gives maximum bioactive compounds was carried out. The selected cereal and pulses (rice, maize, green gram and soy) were germinated for 2, 4, 6 and 8 days at 30 ºC after steeping 12 hrs in tap water. The ungerminated cereal and pulses were used as the control. Then the germinated cereal and pulses were ground into fine particles. The highest total polyphenol content, flavonoid content was obtained in 8 days germinated cereal and pulses compared to control type. The lowest IC50 concentrations for DPPH and ABTS radicals and high FRAP activity were obtained in 8 days germinated cereal and pulses indicating the highest antioxidant activity.
Based on the results obtained from the first stage of the research, 8 days germinated cereal and pulses was selected to formulate the malted milk powders. To obtain the malt mix, 35 % of rice, 35 % of maize and 30 % of green gram which germinated for 8 days were mixed together and obtained malt mix were incorporated into fresh pasteurised liquid milk at three different malt mix to milk ratios of 40:60, 50:50, and 60:40. The malted milk slurry was dried by using the vacuum oven at 50 ºC under 50 mbar pressure for 24 hrs and crushed it into fine powder. The obtained malted milk powder formulations were subjected to characterisation of nutritional, physical and bioactive compound analysis. Increasing the proportion of germinated malt mix in malted milk powder significantly (p < 0.05) enhanced protein, polyphenol, flavonoid content, antioxidant activity, and mineral levels, while reducing fat content compared to powders made with ungerminated mixes. These improvements are attributed to enzymatic hydrolysis during germination, which boosted nutritional quality and bioactivity. Notable changes in microstructure and protein secondary structure also contributed to better dispersibility and solubility. However, formulations with germinated mixes exhibited a darker colour.
In the next step of the research project, all six malted milk formulations were subjected to the in vitro gastrointestinal digestion. Polyphenol and Flavonoid content progressively increased across oral, gastric, and intestinal digestion phases, with MM 60:40 formulations exhibiting superior bioaccessibility compared to CMM samples. Germination-induced enzymatic activity was identified as a key factor in breaking down polyphenol bound complexes, promoting easy exposure to digestive enzymes than CMM samples. The antioxidant activity, measured through DPPH radical scavenging assays, showed a significant rise throughout digestion, aligning with the release of polyphenols and flavonoids. Amino acid bioavailability also improved, with the intestinal phase driving the highest release, supported by enzymatic hydrolysis and reduced starch-protein interactions. SDS-PAGE analysis confirmed extensive protein hydrolysis, particularly in germinated samples, resulting in smaller peptides and free amino acids. Furthermore, mineral bioavailability (Na, K, Mg, Ca, Zn, and Fe) significantly improved in MM formulations due to the reduction of antinutritional factors like phytic and oxalic acids. The intestinal phase displayed the highest mineral absorption, aided by pancreatic enzymes and casein phosphopeptides (CPP), which maintained mineral solubility.
In the final stage of the project, the impact of zinc (Zn) fortification on the nutritional and functional properties of malted milk powder formulations was examined as a strategic response to the global challenge of micronutrient deficiencies. Zinc fortification in malted milk powders significantly enhanced the initial extractable total polyphenol content (TPC), flavonoid content (TFC), and antioxidant activity, particularly in formulations incorporating germinated malt mixes (Zn-MM). MM 60:40 consistently showed the highest bioactive compound levels and antioxidant potential across digestion phases. Zn fortification likely stimulated polyphenol biosynthesis through Reactive Oxygen Species (ROS)-mediated stress and improved solubility of bioactives by altering matrix interactions. However, despite these improvements, Zn fortification occasionally reduced bioactive compound bioavailability during digestion, likely due to complex formation which can reduce solubility. Nevertheless, antioxidant activity (DPPH) remained elevated in Zn-fortified samples, suggesting the presence of stable, functional antioxidant complexes.
Amino acid release varied by phase and formulation, with MM 60:40 showing the highest intestinal bioavailability. Some amino acids strongly bound to Zn (e.g., Cys, His, Asp), limiting their release. Mineral bioavailability, particularly for Zn, Na, Ca, and K, improved during digestion, especially in Zn-MM 60:40. Dialyzable Zn content in this formulation reached 2.20 mg /20 g, covering ~18.6% of the adult RDI. While one serving fell short of delivering half the Recommended Dietary Intake (RDI), 3-4 servings could meet the target. Zn fortification also altered protein secondary structure by reducing β-sheets and increasing random coils, enhancing protein flexibility, solubility, and digestibility.
Together, this study demonstrated that germination significantly enhances the nutritional, functional, and structural properties of cereal and pulses. Incorporating germinated blends into milk not only improved polyphenol and flavonoid content, antioxidant activity, amino acid and minerals but also their bioavailability along the enhanced protein digestibility. Zinc fortification further amplified the antioxidant potential and mineral content, particularly in germinated formulations like MM 60:40, despite some reductions in bioaccessibility of bioactive compounds due to complex formation.</p
Performance Enhancement of Titanium-Composite Joints through 3D-Printed Micro-Pin Reinforcements
No full textFibre Reinforced Polymer (FRP) composites are used across a broad range of engineering applications. Currently, Carbon Fibre Reinforced Polymer (CFRP) composites within aircraft structures have grown considerably, thereby driving significant technological advancements in the manufacturing and processing of composite structures in aerospace engineering. CFRPs offer a high strength-to-weight ratio and superior in-plane specific stiffness relative to monolithic metallic alloys. The integration of CFRPs into metallic-composite hybrid joints is widely adopted in many critical load-bearing structures using adhesive bonding and mechanical fasteners (i.e. bolts, rivets). However, adhesive bonding requires meticulous surface preparation to avoid debonding along the bond line and consequently catastrophic failure of the joint, while mechanical fasteners increase localised stress, leading to overly conservative design and therefore increased structural weight. To extend the life cycle of defence capabilities across air, land and sea platforms, it is critical to understand and address the limitations within conventional joining techniques through the development of innovative joining technologies.
The aim of this PhD was to expand the research of Selective Laser Melting (SLM) titanium (Ti-) micro-pins as an alternative through-thickness joining technology for hybrid titanium-composite joints. The focus of this thesis was to determine the Modes I and II interfacial fracture toughness properties to develop and validate a macro-scale unit-strip Finite Element (FE) model, and to enhance the damage tolerance of aerospace-standard joints. Investigations emphasised the experimental response of Ti-pinned joints compared to unpinned specimens, with the intent to further understand the strengthening and failure mechanisms of Ti-pins under varied loading conditions. The analyses were supported by analytical tools, including Scanning Electron Microscopy (SEM), high-resolution Computer Tomography (µ-CT) and Digital Image Correlation (DIC).
The literature review chapter of this dissertation outlined conventional through-thickness joining techniques – including mechanical fasteners and adhesives – to provide context for state-of-the-art hybrid metal-composite joining. A thorough review was subsequently conducted, focusing on innovative contemporary metal-composite through-thickness joining technologies. Key research contributions associated with each joining technique were examined to identify existing research gaps, with particular attention given to the production of micro-sized pins produced via Additive Manufacturing (AM); from which the core research questions of this study were formulated.
The first research chapter (CHAPTER 3) reported the Mode I and Mode II interfacial fracture toughness properties of titanium-composite joints reinforced with SLM Ti-micro pins. As part of an industry collaboration, joint configurations incorporating film adhesives were also investigated. This chapter provided a detailed description of the manufacturing process for the SLM Ti-pins and joints, as well as the specific composite lay-up adapted from an existing aerial platform. Compared to the control (unpinned joint), the joint configuration featuring only Ti-micro pins exhibited the highest Mode I steady-state fracture toughness, achieving a 18-fold increase (4.62 kJ/m2 compared to 0.25 kJ/m2). Pinned joints enhanced Mode I interfacial fracture through the formation of large-scale bridging zones and strong mechanical interlocking with the composite adherends. Under Mode II loading, the joint configuration containing both pins and film adhesive exhibited the greatest performance, with an almost 12-fold enhancement in steady-state fracture toughness (4.01 kJ/m2 compared to 0.34 kJ/m2). The key toughening mechanisms under Mode II loading include large-scale shear bridging zones, snubbing and fibre-matrix crushing; however, the tricot mesh within the film adhesive further enhanced the bond line adhesive strength. These findings confirmed that SLM Ti-micro pins significantly improve resistance to interfacial fracture under both Mode I and Mode II loading conditions.
The second technical chapter (CHAPTER 4) presented a novel development and validation framework of a unit strip macro-scale FE model of the hybrid titanium-composite joints from CHAPTER 3. Unlike previous studies that employed 1D nonlinear spring elements to model the exclusive mode-dependent traction behaviour, this work incorporated an explicit geometric modelling technique of the Ti-micro pins. Validation of the FE model was performed using experimental results from CHAPTER 3, with the unpinned joint results serving as benchmarks for the pinned joints development. The FE model accurately predicted Mode I steady-state fracture toughness values within 7% and 2% of experimental results for unpinned and pinned specimens, respectively. Key toughening mechanisms, including pin pull-out, large-scale bridging formation, and lateral snubbing with increased frictional pull-out, were successfully captured. Mode II steady-state fracture toughness values were predicted within 9% and 10% of the experimental results for the unpinned and pinned joints, respectively. Mechanisms such as pin shearing, rising R-curve behaviour, crack-growth toughness and rapid crack growth were effectively represented. This chapter presents the successful validation of a macro-scale modelling framework that explicitly incorporates the primary toughening mechanisms associated with through-thickness reinforcements, as well as the damage evolution processes occurring within the hybrid titanium-composite joint.
The subsequent technical chapter (CHAPTER 5) evaluated the performance of hybrid joints, as introduced in CHAPTER 3, which were subjected to cyclic Mode I and Mode II interfacial fatigue loading. Experiments were conducted using cyclic, displacement-controlled conditions; additionally supplemented by single-pin pull-out and single-pin shear traction tests to assess the pin efficacy in both fatigue modes. Pinned joints demonstrated significantly higher strain energy release rates (SERR) at equivalent crack growth rates for both cyclic Modes I and II, with critical SERRs increasing by factors of 18 and 4, respectively. Results demonstrated that SLM Ti-micro pins substantially enhanced the fatigue life of hybrid titanium-composite joints, with critical strengthening mechanisms including crack bridging formation behind the crack tip, snubbing, and plastic-induced two-stage pin shearing. In addition to understanding the fatigue strengthening mechanisms, this chapter provided supporting fractographic evidence to enhance understanding of these underlying processes.
The final technical chapter (CHAPTER 6) examined the enhanced performance under tensile loading of three joint configurations featuring SLM Ti-micro pins: single step, double step, and symmetric lap joints. DIC was employed to evaluate strain contours across the bond line, demonstrating the effectiveness of the pins in reducing peel stress at critical run-out regions. Experimental results indicated that joint configurations with reduced loading eccentricity exhibited superior performance and minimised peel stress. The symmetric lap joint achieved the highest peak failure load, representing an 81% improvement over the pinned single-step joint. This configuration significantly reduced load path eccentricity, as confirmed by DIC, which revealed minimal transverse strain prior to failure. Joints subjected to higher peel stresses at run-out regions, such as the pinned single-step joint, displayed distinct pin fracture surface differences between run-out and lower peel stress areas, as supported by fractographic evidence. These findings offer valuable insights not only for mitigating disbonding issues in critical applications, such as multi-step lap joints in aerial platforms, but also for informing novel design strategies aimed at enhancing damage tolerance, load-bearing capacity, and extending the service life of dissimilar joined structures across a broad range of engineering applications.</p
Exploring the continuing effects of COVID-19 on tertiary screen production education in Australia
No full textThis article considers how the COVID-19 pandemic impacted tertiary-level screen production education in Australia. Six university educators across four Australian states present a series of critical thematic reflections, interrogating their lived experiences of teaching screen production courses during periods impacted by COVID-19 lockdowns and social distancing requirements. The analysis reveals the pandemic amplified areas like concept development and fundamental production skills using mobile devices, while more advanced technical skills and student collaboration suffered due to remote learning conditions. Managing health risks through COVID-safe protocols became a major priority. Student storytelling shifted towards shorter individual projects exploring themes of isolation, though some collectives producing anthology series also emerged. While some pandemic-driven changes like online meetings have persisted, the authors identify an ongoing need to foster students’ interpersonal skills and technical proficiency developed through collaborative, hands-on learning experiences. The diverse reflections highlight common challenges but also differences across states based on varying COVID-19 conditions and restrictions. Overall, the authors argue for balanced, responsive approaches going forward to equip graduates with frameworks to navigate screen industry shifts alongside changing student expectations around delivery modes.</p
Advancing global mass timber construction - a decade of progress, challenges and future directions: A systematic literature review
No full textMass Timber Construction (MTC) is an umbrella term for a group of engineered timber products and a process for construction for a more sustainable built environment. Whilst MTC is seen as a viable substitution for more traditional carbon-intensive construction approaches, industry uptake and wider adoption are relatively slow. Despite the adoption challenges, substantial change has occurred in industry and research domains as MTC enters its second decade as a commercial offering around the world. A comprehensive systematic literature review was undertaken to clarify the complexities of the global MTC market, identify knowledge gaps and highlight barriers to wider adoption. The review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology/approach. A systematic review of 81 papers across 51 different journal publications spanning 10 years was conducted and five themes were interpreted. The outcomes from the review may support the next evolution of research activities and provide details for roadmaps for further advancement of MTC technology. The findings suggest several key recommendations to advance MTC adoption: implementing Translational Design and Construction (TDC) to accelerate industry applications; developing innovative solutions for housing needs; creating dynamic Environmental Product Declarations; incorporating Circular Economy principles; fostering interdisciplinary collaboration; building consumer confidence through education; establishing integrated urban policies; and enhancing durability through hygrothermal monitoring and advanced research.</p
Blended brown coal and Class F fly ash based geopolymer
No full textGeopolymer concrete has been shown to be a suitable option to overcome the challenges of carbon emissions from Portland cement (PC) and the landfill storage of brown coal fly ash (BCFA). Earlier studies have demonstrated that geopolymer bricks made with high-crystalline BCFA achieve strengths of 5–15 MPa, while geopolymer concrete reaches around 30 MPa, but both require curing at 120 °C. This temperature is impractical for commercial brick production, as most manufacturing facilities operate at a maximum of 80 °C. To address these issues this study examines the compressive strength and microstructural evolution of BCFA and Class F fly ash (FA) blended geopolymer mortar at 80 °C curing. The study employs different sodium hydroxide-to-sodium silicate activator ratios. The Na2O dosage is fixed at 15 % over a range of Alkali Modulus (AM), 1.0, 1.25, 1.50 and 1.77. The study utilizes an extensive range of characterization and microscopy techniques to study the evolution of the hydration process. The study identifies 15 % Na2O and AM 1.25 as optimum alkali activator dosages. This achieves a 40 % utilization of BCFA (B40–1.25) with a concrete strength of 39.40 MPa (7 days) and 38.97 MPa (28 days). In addition, this optimum design with 70 % utilization of BCFA attained strengths of 18.92 and 23.30 MPa at 7 and 28 days, respectively, suitable for brick production. The formation of N-A-S-H and/or C-A-S-H gel combined with the crystalline phases of the optimum mix (70 % BCFA and 30 % FA) are primarily responsible for achieving these strengths at the reduced curing temperature of 80 °C.</p
Computer-mediated representations: A qualitative examination of algorithmic vision and visual style
No full textTo the general public, text-to-image generators, such as Midjourney and DALL-E, seem to work through magic and, indeed, their inner workings are often frustratingly opaque. This is, in part, due to the lack of transparency from big tech companies around aspects like training data and how the algorithms powering their generators work, on one hand, and the deep and technical knowledge in computer science and machine learning, on the other, that is required to understand these workings. Acknowledging these aspects, this qualitative examination seeks to better understand the black box of algorithmic vision through asking a large language model to first describe two sets of visually distinct journalistic images. The resulting descriptions are then fed into the same large language model to see how the AI tool remediates these images. In doing so, this study evaluates how machines process images in each set and which specific visual style elements across three dimensions (representational, aesthetic, and technical) machine vision regards as important for the description and which it does not. Taken together, this exploration helps scholars understand more about how computers process, describe, and render images, including the attributes that they focus on and tend to ignore when doing so.</p