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Mapping cross-national conceptions of essential energy to advance housing energy justice - Transcripts
No full textThe project entailed qualitative research from focus groups and urban tours. The study leveraged the cross-national collaboration of the WELLBASED project. WELLBASED was a European Union Horizon 2020 project that was trialling energy poverty interventions between 2021 and 2025 across six cities: Leeds (UK), Valencia (Spain), Heerlen (Netherlands), Edirne (Turkey), Obuda (Hungary) and Jelgava (Latvia). The study captured and compared the WELLBASED professionals’ perceptions of essential energy.</p
Toxicity of Chemicals in Unconventional Gas Wastewaters to Selected Australian Freshwater Invertebrates
No full textUnconventional gas extraction utilises hydraulic fracturing involving high-pressure water, silica
sands, and other additives to extract natural gas from underground reservoirs. This process produces
large volumes of chemically complex wastewaters, which must be managed or treated to reduce
toxicity. Spills and leaks from storage and transporting these waters are potential avenues of exposure
for freshwater invertebrates. The mechanisms and magnitude of toxicity of these wastewaters have
become an emerging research field to address this knowledge gap. Subsequently, the knowledge
gained provides greater insight into potential environmental implications that enable better
management and informed decisions.
The research presented in this thesis attempted to evaluate and further understand the toxicity of these
wastewaters by first comprehensively reviewing and evaluating common chemicals found in these
wastewaters (Chapter 2) and selecting the least studied and/or those predicted to have effects on native
freshwater species, especially in combination, to study experimentally. The selected chemicals were
barium, o-Cresol and sodium chloride. The chemicals barium (ensuring confounding effects of sulfate
reacting with barium were addressed) and sodium chloride were evaluated for their chronic toxicity
as single and binary chronic exposures to measure survival (parents) and reproductive effects (number
of neonates) using the water flea Ceriodaphnia dubia (Chapter 3). Results indicated barium and
sodium chloride at concentrations found in onshore unconventional gas wastewaters and further
diluted in impacted surface waters reduced the population of C. dubia. In a surface water
environment, there could be a potential shift in species composition to those that are more tolerant to
barium and sodium chloride. The acute toxicity (survival) of all three chemicals was also assessed as
single chemical exposures, and binary and ternary mixtures using the freshwater shrimp Paratya
australiensis, in combination with sub-lethal assessments using the enzyme assays glutathione S-
transferase, acetylcholinesterase and sodium-potassium adenosine triphosphatase (Chapter 4). These
enzyme assays provided a more sensitive indicator for sub-lethal perturbations from these chemical
exposures. These enzymes have roles in detoxification, nerve signalling, energy and osmoregulation.
Adverse changes to enzyme activity have implications for reducing shrimps’ overall fitness. Shrimp
in the environment may become more susceptible to illness or increased predation pressures.
The concentrations of barium and sodium chloride tested (Chapters 3 and 4) were environmentally
relevant, particularly to enclosed surface water environments impacted by inorganically/metal-rich
wastewaters from shale gas (Chapter 2). Reproduction was adversely affected in C. dubia at ≤16
mg/L of dissolved barium. However, parent C. dubia survival was unaffected at these concentrations,
suggesting that dissolved barium caused a shift in energy or cellular resources away from
reproduction. Relatively small additions of sodium chloride (approximately 200 mg/L) increased
reproduction, but further additions (approximately 400 mg/L) were detrimental to reproductive output
and parent survival. A portion of the binary barium and sodium chloride combinations suggested
some antagonistic interactions (Chapter 3), though a more comprehensive assessment is needed.
Shrimp acute (96-hours) survival was reduced from 10 mg/L dissolved barium, 5.4 mg/L o-Cresol
and 3100 mg/L sodium chloride. Mortality occurred more gradually across the concentrations tested
for dissolved barium (10 to 105 mg/L) and sodium chloride (approximately 1000 to 6000 mg/L),
while a sharp increase in mortality occurred from o-cresol exposure from 5.4 to 21.8 mg/L. Synergism was observed in binary mixtures of barium and o-Cresol. The o-Cresol and sodium chloride binary
combinations showed greater synergistic responses than barium and sodium chloride exposures.
Ternary mixtures were highly synergistic. However, the three enzyme assays (glutathione S-
transferase, acetylcholinesterase and sodium-potassium adenosine triphosphatase) generally showed
inconclusive trends. This was thought to result from high sample variability since wild-collected
shrimp were used for the experiments, and replication of samples was reduced due to the high
mortality of shrimp in higher concentration treatments.
After investigating select and prominent chemicals in unconventional gas wastewaters, research
progressed to investigating chronic toxicity of a shale gas flowback wastewater sample using the
water flea Daphnia carinata (Chapter 5) and Paratya australiensis (Chapter 6) to provide further
environmental context to the previous work on the toxicity of select chemicals within these
wastewaters (Chapter 3 and 4). Daphnia carinata showed significantly increased reproduction at
0.5% dilution of this water sample. Still, reproduction was reduced at lower and higher test
concentrations, likely due to an interaction between this wastewater sample's salinity and water
hardness. Increased reproduction was linked with increased size (length) of individuals, which was
generally promoted by the wastewater compared to its major ion salinity controls and control group
across different aged D. carinata. It was interpreted that the chemically complex inorganic-rich
wastewaters at these dilutions provided additional nutrients that supported growth. Sub-lethal
oxidative stress activity was measured using the biochemical assays of glutathione S-transferase, lipid
peroxidation, reactive oxygen species and superoxide dismutase. Generally, activity in the wastewater
treatments was either reduced non-significantly or significantly compared to the control and major
ion salinity control, with a clear trend observed with reactive oxygen species activity decreasing with
exposure to increasing wastewater concentrations. Metabolomics and lipidomics assessment showed
the wastewater sample caused greater perturbations in both lipid and metabolite compounds in D.
carinata compared to those in the salinity control. Paratya australiensis (Chapter 6) was not
adversely impacted regarding increased mortality from exposure, except at the highest 1%
wastewater. At these dilutions, the toxicity shifted to a suspected iron-oxyhydroxide particle in the
wastewater, clogging and damaging gill tissues, reducing respiration, causing hunger and eventually
death. These same shrimps showed greater metabolite and lipid perturbations, and central carbon
metabolism metabolites were generally enriched in this treatment compared to other more dilute
wastewater samples, as well as the salinity controls and control. Key metabolic pathways were
enriched in shrimp exposed to the wastewater, indicating a shift towards fat and protein degradation.
In conclusion, the results of this research present substantial evidence that unconventional gas
wastewater chemicals or whole untreated samples from this industry can be toxic to freshwater
invertebrates and, importantly, at dilutions relevant to surface waters impacted by spills or leaks of
these wastewaters. These wastewaters can also be highly variable in chemical composition and thus
vary in toxicity. Further research on the toxicity of these wastewaters could involve a mesocosm
approach using freshwater biota. This would further increase environmental relevance as predator-
prey interactions are considered and abiotic conditions are better simulated to those in surface water
ecosystems.</p
Paradoxes in Cross-functional Innovation Teams: How Designers Transcend Individual Level Tensions to Enhance Collaboration
No full textDesign has emerged as critical to successful innovation yet integrating design preferences with those of other disciplines proves challenging. This research aims to understand how individual designers experience interdisciplinary collaboration in the context of a cross-functional innovation team, and subsequently how they work to manage collaborative tensions. A qualitative, abductive approach has been taken, through n=58 semi-structured interviews with designers and non-designers working in cross-functional innovation teams. Following existing research in the field, a paradox perspective has been adopted to investigate collaboration tensions. It was found that designers experience paradoxical tensions associated with paradoxes of performing and belonging when collaborating with non-designers, which are brought to saliency due to factors in the cross-functional team environment. It was found that designers may interpret paradoxical tensions through the lens of their design remit, navigating paradoxical collaboration tensions by engaging as either a designer or a team member (or ideally, both). In doing so designers were able to both demote (relent on) and promote (advocate for) their design remit in relation to their team member role. Practices were identified that enabled designers to confront, and ultimately transcend paradoxical collaboration tensions. Practices which did not enable the transcendence of paradoxical collaboration tensions were also identified. This research contributes to theory by extending our understanding of how paradoxes emerge for designers in cross-functional innovation teams, and how these paradoxes can be engaged at the individual level. In particular, this research introduces a new paradoxical framing: Demotion vs Promotion. Further, it offers practical suggestions to enhance interdisciplinary collaboration by designers to improve innovation outcomes.</p
Advancing Detection Strategies for Emerging Pesticides in Surface Waters
No full textRecent advancements in pesticide development have led to the emergence of bioactive compounds, posing potential risks to non-target organisms and ecosystems. Despite global monitoring initiatives, deficiencies in sampling, analysis, and risk assessment hinder the identification of novel pesticides and associated risks. This research addresses these challenges through a comprehensive approach, integrating innovative sampling techniques and robust analytical methodologies.
Chapter 2 served as a foundational element, providing a detailed literature review. It began with an examination of emerging pesticides approved for use in Australia, addressing associated concerns and constraints within the regulatory process. The chapter then transitioned to environmental water monitoring, delving into the significance of passive sampling technology for pesticide surveillance in aquatic systems, along with an assessment of its various designs and limitations. The latter sections concentrated on sampling and extraction techniques in chromatographic analysis. The chapter concluded with an evaluation of chromatographic techniques and the potential of high-resolution mass spectrometry for environmental pesticide monitoring. Through this, Chapter 2 not only provided a succinct overview of the current landscape but also guided the development of effective methodologies in subsequent chapters.
In Chapter 3, a novel method prioritised pesticides for monitoring by combining registration data with laboratory monitoring capacity. Applied in Victoria, Australia, this approach identified 144 pesticides, emphasizing the need to broaden monitoring beyond traditional categories. The study introduced a refined prioritization model that considers both potential toxicity to local ecosystems and the likelihood of local usage, serving as a practical starting point for environmental practitioners and researchers. This method supports a periodic prioritization model that enables the continuous identification of new pesticides, aligning with the evolving landscape of pesticide products and catchment land-use activities.
Chapter 4 validated the prioritization method in Greater Melbourne, employing passive sampling devices and suspect screening via ultra high-performance liquid chromatography (UPLC)-high resolution mass spectrometry (HRMS). This approach effectively identified 21 potential pesticides, confirming the presence of five emerging pesticides in Australian surface waters for the first time. The study highlights the efficacy of passive sampling in detecting sporadic pollution, covering a range of polarities, and offering a valuable alternative to conventional methods like grab sampling. The integration of HRMS technology in a suspect screening approach proves robust and efficient for screening numerous potential pesticides in environmental water monitoring and risk assessment programs.
Chapter 5 delved into the seasonal occurrence of fungicides within the Greater Melbourne area (GMA), emphasizing the impact of weather events on pesticide transport. The study recommends thorough monitoring before and after significant rainfall events to enhance understanding of novel fungicide behaviour within surface water systems. The findings underscore the importance of continuous and long-term monitoring of recently registered fungicides, considering their potential impact on aquatic organisms.
Chapter 6 introduced a novel analytical method based on Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction and UPLC tandem mass spectrometry (MS-MS), to accurately quantify four novel fungicides in surface water systems at environmentally relevant concentrations. The method's sensitivity, precision, and repeatability are demonstrated through validation, emphasizing its reliability for environmental analysis. Application of the method to real-world surface water samples from Greater Melbourne reveals varying concentrations of the detected fungicides, with notable implications for environmental impacts and potential risks to non-target aquatic organisms.
The hybrid approach of passive sampling, grab water sampling, and advanced analytical techniques, as demonstrated in Chapters 4, 5, and 6, enhances the understanding of pesticide occurrence in regional surface water systems. Insights from these chapters underscore the need for continuous and long-term monitoring, especially for recently registered pesticides, contributing to robust ecological risk assessments.
My research proposes a proactive monitoring framework, periodically aligning with new pesticide approvals, and emphasizes the importance of global collaboration and data sharing for comprehensive risk assessments. Future recommendations include refining prioritization methodologies, optimizing passive sampling techniques, and further improving analytical capacities for detecting novel pesticides. Overall, this research contributes valuable insights to the field of pesticide monitoring in surface waters and lays the foundation for effective environmental management and regulatory initiatives.</p
Methods and outputs JIBE model
No full textThrough the JIBE project (Joining Impact models of transport with spatial measures of the Built Environment), we have developed agent-based transport simulation models (ABMs) capable of depicting complex urban systems. These ABMs model how street-level built environment exposures influence behaviour, accessibility and health with high spatial and demographic granularity. By forecasting travel itineraries, behaviours, exposures, and health for a synthetic population of individuals, these ABMs allow us to simulate scenarios of interest to health and transport planners. These presentations include an introduction to the projects, methods and outputs. </p
Novel Responsive Lipid Nanoparticles for Multidrug-Resistant Organism Therapeutics
No full textMultidrug-resistant organisms (MDROs) are a type of microorganism that have evolved defences against many classes of antibiotics. Given the limited ways of treating MDRO-associated infections, they are now considered a threat to global health. Thus, research for the next generation of antimicrobial technologies is focusing on developing targeted therapies against which harmful bacteria cannot acquire resistance. Research on lipid nanoparticles (LNPs) with cationic lipids shows promise as treatment tools for addressing these drug resistance challenges.
This project aims to develop novel LNPs with tuneable surface charges and inverse lyotropic liquid crystalline mesophases, both known to promote membrane fusion and interaction. The hypothesis is that by tuning these two properties (charge and mesophase) using different compositions of helper lipids and cationic/ionisable lipids, the formulated novel LNPs can effectively interact with specific MDROs. The lipids used in the study included monoolein (MO) as the main structure-forming lipid, which can self-assemble to a range of lyotropic liquid crystalline mesophases, including the fascinating cubic and hexagonal phases known to promote membrane fusion, 1,2-dioleoyl-3-trimethylammonium propane (DOTAP; a cationic lipid), ALC-0315, and SM-102 (two ionisable lipids).
The LNPs exhibited typical particle sizes and good dispersibility. After a month of storage, some LNPs displayed decreasing particle sizes, indicating lipid rearrangement and particle aggregation without significant deterioration. Notably, the LNPs possessed a positive surface charge under specific conditions, making them potentially interactive with negatively charged cell membranes. This positive charge was dose-dependent and remained stable over time, highlighting the potential biological significance of the size and surface charge of LNPs. The study also delved into the pH-responsive behaviour of the LNPs, showing that the chemical composition and concentration of added lipids, as well as pH conditions, influenced the internal mesophases of the LNPs. Furthermore, adding oleic acid (OA) to LNPs enhanced their interactions with microorganisms, leading to changes in particle size, surface charge, and structural transitions and potentially impacting microorganism interactions.
Among the tested LNPs, SM, and DOTAP showed the most significant inhibition of E. coli growth, with other LNPs exhibiting moderate toxicity. Cellular confocal laser scanning microscopy imaging indicated that MO and ALC LNPs had similar toxicity, while DOTAP and SM LNPs showed notably stronger antimicrobial effects. The addition of OA to LNPs significantly enhanced their antimicrobial activity against E. coli; extended incubation further confirmed the impact of OA-containing LNPs on bacterial growth, highlighting their potential as effective antibacterial agents.
The experiments demonstrated the effectiveness of MO, ALC, and SM LNPs in inhibiting methicillin-resistant Staphylococcus aureus (MRSA) growth. In particular, MO exhibited strong inhibitory effects on bacterial growth, surpassing positively charged LNPs containing ionisable and cationic lipids. The incorporation of OA in LNPs enhanced the inhibition of MRSA in short-term PBS treatment but not during long-term broth treatment. Notably, DOTAP LNPs, with or without OA, were less effective against MRSA than other LNPs, raising questions about the role of inverse lyotropic liquid crystalline structures in LNPs and their bacterial interactions.
Finally, the interaction and inhibitory effects of LNPs were assessed on sensitive and resistant (to amphotericin B and fluconazole) strains of Cryptococcus neoformans. The determinants affecting LNP–fungi interactions are multifaceted, encompassing LNP composition, physicochemical attributes, fungal strains, and growth conditions. Despite these challenges, a consistent trend emerged, highlighting the fusogenic cubic phase, especially that of MO, as a top attribute for disrupting fungal cell walls, even though these walls are more rigid than cell membranes. Positively charged LNPs tended to have a greater disruptive effect on fungi.
LNPs possess stable positive surface charges and can be further enhanced with the addition of OA to improve interactions with microorganisms. In summary, the findings indicate that LNPs with fusogenic cubic phases and positive surface charges hold promise as versatile antimicrobial agents with potential applications in addressing MDRO challenges.</p
Development and Evaluation of a Multilayered Small-Diameter Vascular Graft for Limb Ischemia
No full textDespite extensive research on tissue-engineered and artificial small-diameter vascular grafts, with the exception of the expanded polytetrafluoroethylene (ePTFE) and polyester (PET) artificial grafts no other newly engineered grafts have proved to be clinically viable. The ePTFE and PET grafts have been found to occlude within less than 5 years after implantation due to the formation of thrombosis and intimal hyperplasia. Intimal hyperplasia is triggered mainly by compliance mismatch between the native artery and the implanted artificial conduit as well as bio incompatibility of the graft surface. Therefore, in this study we aimed to fabricate a biostable, multilayered small-diameter vascular graft with optimised compliance and an antithrombotic luminal surface.
Three polymers (polymethyl methacrylate (PMMA), polydimethyl siloxane (PDMS) and thermoplastic polyurethane (TPU)) were selected for the fabrication of the vascular graft utilising electrospinning, taking into consideration their biostability and biocompatibility. TPU and PDMS, well known for their elasticity, were selected to impart optimal mechanical properties while PMMA served as a carrier polymer to impart nonlinearity to the overall structure due to its brittleness. The first section of the study optimised the fabrication technique including polymer concentrations, solvent utilised and their combinations as well as selection of the most suitable electrospinning parameters. The developed nanofibers were then characterised in terms of the physical, morphological and mechanical properties. The optimal PMMA:PDMS ratio of 1:3 was selected and utilised throughout for all the remaining investigations. Coaxial electrospinning with TPU as the core was utilised to address the limited extensibility observed when using only PMMA and PDMS. The incorporation of TPU in the fibres resulted in enhanced elasticity and strength. These coaxially electrospun nanofibers were then used as the mechanically reinforcing layer of the vascular graft. TPU was further added as the outer layer to anchor the artificial conduit to the surrounding tissue. For the luminal layer MXene nanoparticles were added to the PMMA: PDMS fibres to enhance the wettability and impart radiopacity to the vascular graft. The effect of adding the nanoparticles were then investigated in terms of hemo and biocompatibility. To further enhance functionality of the luminal surface two strategies were then used aiming to deter protein and platelet adhesion and enhance the rate of endothelialisation. The PMMA:PDMS nanofibers were then functionalised with heparin using a polydopamine bridge, resulting in enhanced antithrombotic properties. The polymer 2-Methacryloyloxyethyl phosphorylcholine (MPC) was also grafted onto the nanofiber surface to deter protein and platelet adhesion. Results showed that the MPC successfully deterred both protein and platelet adhesion as well as endothelial cell adhesion. The final section of the study utilised simulations to better understand the effect of biomechanical mismatch between the vascular graft and the native artery. Variations in the elasticity of the vascular conduit were found to have profound effects on the wall stress of the native artery, mainly at the anastomosis.
The successful development and fabrication of a highly elastic synthetic graft with nonlinear mechanical behaviour is a great advancement towards combating intimal hyperplasia in synthetic conduits. The ability to easily tune its elasticity by utilising the thickness of the artificial graft shows great potential in the fabrication of patient specific artificial grafts.</p
Australian Urban Observatory Paid Partnership Prospectus 2024
No full textThis is a propspectus that describes how the AUO is an intuitive digital liveability planning platform that transforms complex urban data into easily understood liveability indicators across 9 categories.</p
Investigation of Mycelium Composite for Acoustical Ceiling Tile Application
No full textMycelium composites have gained considerable attention for their environmental credentials. While there is much public enthusiasm surrounding the material, it has struggled to find widespread adoption. Packaging has been mycelium composites most successful application, but it remains niche and expensive. Mycelium composites have been considered for many construction applications such as brick, insulation, and boards, however these occupy an even smaller commercial niche and are mostly used artistically. Acoustic panels have gained growing commercial interest as they are non-structural and utilize mycelium composites’ good acoustic properties. However, acoustic ceiling tiles constructed of mycelium composites have yet to be researched given the higher product standards. This master’s research explores the feasibility of mycelium composites for use as an acoustic ceiling tile application. Feasibility is determined by characterizing mycelium composites’ strength and acoustic properties. Further, mycelium composites’ strength is explored by investigating spent brewer’s grain as an alternative substrate and hybridizing all sample types with hydrated gypsum.
The testing explored in this research aims to capture the various strength and acoustic properties of mycelium composites specific to acoustic ceiling tiles. Strength testing includes flexural, hardness, friability, and humidity deflection. Strength tests identified the most suitable sample for acoustic testing. Then acoustic testing was conducted to characterize the materials at both normal and random incidence. To do this an impedance tube, a small sound reverberation room and the two cavity analysis were used. The Armstrong Ultima acoustic ceiling tile was used the commercial baseline.
As mycelium composites are fabricated in a variety of ways, this research explored hybridization and substrates in the context of improving strength. For hybridization, samples were hybridized with hydrated gypsum at 10, 20 and 30 percent concentrations and tested for flexural and hardness strength. For substrates, spent brewer’s grain was examined in relation to the common hemp shive substrate and used in all strength tests but was not suitable for acoustic tests. All samples were then analyzed by computerized tomography and scanning electron microscopy. Together these results provide a complete picture of how one type of mycelium composite could perform as an acoustic ceiling tile.
Results and analysis indicate that while mycelium composites can meet acoustic ceiling tile standards, they are impractical for this application. Compared to the Armstrong Ultima ceiling tile, mycelium composites are weaker in flexural and hardness strength but slightly better in friability and humidity deflection. Acoustically, mycelium composites can be good absorbers however results are inconsistent, and the material itself is difficult to be made consistently. Further hybridization with gypsum does little to improve strength and its cost is prohibits its use at a large scale. The manufacturing time required for each sample further reduces its practical usage. The general conclusion from the literature review is that hybridization does not improve mycelium composite strength compared to high preforming unhybridized samples. For substrates, the commercially preferred hemp shive is a far more suitable substrate than spent brewers grain. Overall, this research suggests mycelium composites have enough strength and acoustic performance for an acoustic ceiling tile application but are generally impractical due to inconsistent performance, low dimensional tolerances, long manufacturing time, and low hardness.</p
