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An Integrated Model of Social Media Brand Engagement: A Case of Homebuyers in Vietnamese Luxury Residential Properties
No full textVietnam stands out as a remarkably social media-savvy country, boasting more than 72 million users in 2021. This figure is especially notable when considering the context of a global user base that exceeds 4.62 billion. The pervasive influence of social media has revolutionized the dynamics between brands and consumers, transitioning from simple online discussions to complex networks for interaction and engagement. Driven by technological advancements and evolving consumer needs, it now critically shapes brand perceptions and purchase choices. In the past, brands controlled the narrative around their products and services through traditional advertising. However, social media enables consumers to share their genuine brand experiences, fostering transparency and authenticity. This shift means consumers often trust peer reviews more than direct brand messages. To navigate this new landscape, brands are embracing genuine engagement on social media, showcasing their values, sharing exclusive content, and cultivating direct relationships with consumers. In the luxury residential property market, homebuyers often bypass traditional media due to its limited buyer-seller engagement and, instead, they turn to social media communities for insights from peers. This trend underscores the importance of buyer-seller engagement, which is essentially the process of building and maintaining positive relationships with potential and existing customers through regular interactions and communication. Significantly, it is a critical component of successful sales and marketing strategies as it helps to nurture relationships, generate leads, and close deals. Despite this, many property developers still prioritize traditional media marketing, which, unfortunately, potentially reduces transparency and hinders more effective interactions. Recent research has highlighted the critical role of firm-generated content and user?generated content, social media influencer endorsement, and self-image congruence in fostering brand interaction. Nonetheless, a comprehensive understanding of how precisely these elements influence brand trust and purchase intention through social media brand engagement remains elusive. In particular, the extant literature offers limited insights into consumer motivations behind engaging with diverse forms of firm- and user-generated content, escalating consumer scepticism towards social media influencer endorsement, and variances in brand engagement among different age demographics aligning with their self-image. Moreover, there is a notable 2 absence of research exploring the mediating role of social media brand engagement in the relationships between firm-generated content and user-generated content with brand trust and purchasing intention and how distrusted content negatively impacts social media brand engagement. Additionally, the role of social media influencer endorsement as a moderator between firm-generated content and social media brand engagement and self-image congruence as a moderator between user-generated content and social media brand engagement have been ignored. Using theories of uses and gratifications and self-congruence, this thesis aims to highlight the role of social media brand engagement as a mediator, enhanced by the moderating effects of social media influencer endorsement and self-image congruence. Combined with firm-generated content and user-generated content, these factors form the integrated SMBE model, providing property developers with a comprehensive social media marketing blueprint. This refined strategy not only amplifies brand resonance but also nurtures homebuyer trust, ultimately fostering genuine home purchasing intentions. By leveraging this strategy, property developers can minimize negative brand interactions and seamlessly transition from mere brand awareness to actual purchase motivation among potential homebuyers. To address the above goal, this study has six research objectives: 1) examine the relationships among the determinants and outcomes of social media brand engagement; 2) test the mediating effect of social media brand engagement in linking its determinants to its outcomes; 3) examine the moderators of social media brand engagement; 4) explore the typologies of FGC and UGC that customers interact with on social media that lead to their social media engagement; 5) explore the attitude of consumers towards brand endorsements by social media influencers; and 6) explore their engagement behaviours across different age groups when their self-image aligns with the targeted brand. This thesis adopted a mixed-methods approach to investigate the mechanisms and operations of social media brand engagement in the Vietnamese luxury residential property market. Study 1 involved a paper-based survey conducted with 516 homebuyers, focusing on quantitative analysis. The key objectives of this study were: 1) to examine the relationships among the determinants and outcomes of social media brand engagement, providing insight into how various factors interplay to influence brand engagement on social media; 2) to test the mediating role of social media brand engagement, specifically assessing how it links its 3 determinants (such as firm-generated content and user-generated content) to its outcomes (like brand trust and purchase intention); and 3) to investigate the moderating factors that might influence the strength or direction of social media brand engagement (like social media influencer endorsement and self-image congruence). For this study, the data analysis was conducted using two statistical software packages: SPSS version 26 and AMOS version 20, allowing for a robust and comprehensive examination of the quantitative data. Study 2, on the other hand, delved into qualitative analysis through six focus group discussions with a total of 30 homebuyers. The objectives of this study were more exploratory and focused on understanding deeper consumer insights: 4) to explore the typologies of firm?generated content and user-generated content that customers interact with on social media, shedding light on what types of content are most effective in engaging consumers; 5) to explore consumer attitudes towards brand endorsements by social media influencers, understanding how these endorsements impact consumer perceptions and behaviours; and 6) to investigate social media engagement behaviours across different age groups, especially when their self-image aligns with the targeted brand, offering insights into how personal identity factors into social media engagement. The qualitative data from these focus groups were analysed using NVivo version 11 software, facilitating a nuanced understanding of the themes and patterns within the discussions. The thesis makes several significant theoretical contributions to the field of social media brand engagement and real estate purchase behaviour. Firstly, by employing theories of uses and gratifications and self-congruence, the thesis provides an integrated social media brand engagement model in the luxury residential property market. This model encompasses both the quantifiable aspects of consumer behaviours and the deeper, subjective experiences of buyers. Secondly, this study deepens the understanding of the relationships between firm?generated content, user-generated content, and social media brand engagement in the luxury residential property industry. Quantitative findings reinforce previous studies’ work on the firm?generated content and social media brand engagement link while qualitatively highlighting the motives behind consumer engagement with firm-generated content, emphasizing its types of visual appeal, information richness, and emotional connection, elements that have been overlooked in existing literature. 4 Quantitative results also reconfirm an empirical link between user-generated content and social media brand engagement, building upon previous studies in the luxury residential property industry. The qualitative findings illuminate motivations driving engagement with user-generated content, emphasizing its types of authenticity, personal narratives, and context relevance. A significant theoretical contribution is the comparative analysis of user-generated content and firm-generated content, demonstrating user-generated content’s stronger influence on social media brand engagement. This calls for an optimal balance between both content forms, advancing the social media marketing discourse. Thirdly, the quantitative study empirically demonstrates the role of social media brand engagement in fostering brand trust and purchase intention within luxury residential properties. Unique to this study, social media brand engagement is introduced as a mediator between firm?generated content, user-generated content, brand trust, and purchase intention. Contrary to previous studies, qualitative results delve into the negative consequences of distrusted social media content on social media brand engagement. Fourthly, this research pioneers the examination of social media influencer endorsement and self-image congruence as moderators of social media brand engagement. While earlier studies have hinted at closely related moderators, this study dives deep into social media influencer endorsement’s positive moderating role between firm-generated content and social media brand engagement and self-image congruence’s negative moderating role between user?generated content and social media brand engagement. The qualitative findings emphasize the importance of authenticity in influencer endorsements, spotlighting consumer scepticism. Furthermore, this research unpacks the role of self-image congruence, highlighting generational differences in brand engagement behaviours rooted in self-image considerations. Younger individuals aged 30-44, seeking societal validation, display higher self-image congruence than their older counterparts aged 45-65, who value privacy. This divergence presents valuable theoretical insights. From a practical standpoint, firstly, the research provides crucial insights for marketers, especially in the luxury residential property industry. It emphasizes the importance of implementing an integrated social media brand engagement model. This model is pivotal in fostering enriched interactions between brands and consumers. Secondly, the study highlights how enhanced interactions, characterized by their meaningful, personalized, and responsive 5 nature, can significantly elevate customer trust. This aspect is particularly vital in scenarios involving high-value transactions, potentially leading to an increase in sales and brand advocacy. Thirdly, the importance of effective social media brand engagement is underscored. This engagement transcends mere traditional advertising, encompassing the creation of engaging content and the fostering of community spirit. Such engagement is crucial in today’s digital marketplace. Fourthly, the study stresses the need for customized social media strategies catering to diverse market segments. This customization enhances the relevance and effectiveness of marketing campaigns. Finally, the study advocates for a strategic approach towards social media engagement. By leveraging this approach, businesses can build trust, drive sales, and cultivate long-term consumer loyalty. This comprehensive strategy underscores the practical implications of the study’s findings in the realm of digital marketing and consumer engagement.</p
Why Don’t Small Business Owners Take Professional Advice? A Dyadic Study From a Client and Adviser Perspective.
No full textConsiderable evidence shows that small businesses who take professional advice reduce risk and increase growth and success (Lussier & Pfeiffer, 2002; Berry et al., 2006). Despite this, small business owners (SBOs) take professional advice less readily than larger, well-resourced organisations, and have a greater tendency to reject advice received (Mole, 2016). Demonstrating importance, small businesses contribute to the economic success of many countries (OECD, 2019), and in Australia and New Zealand, represent more than 95% of businesses and provide employment to almost half and one-third of the respective population (ASBFEO, 2022; OECD, 2019). However, despite significance, the majority of small businesses fail within five years (ASIC, 2019), and a key reason for their failure is not taking professional advice (Waters, 2013). Further, most professional service advisers (PSAs) perceive the rejection of advice as a negative indicator of their skills and abilities (Belkin et al., 2018), so not taking professional advice has ramifications for both SBOs and PSAs. Accordingly, the implications of not taking professional advice are significant, and understanding the reasons why this occurs and what advisers can do about it, is of value to contemporary marketing literature and managerial practice. Accordingly, this study aims to answer the following research questions: (RQ1) Why don´t SBOs take professional advice, and (RQ2), What strategies are used by PSAs to mitigate advice rejection and facilitate advice uptake by SBOs.
Current B2B and services marketing literature agrees that professional advice is particularly important in contexts that involve complex and service-intensive offerings such as solutions (Tuli et al., 2007), hybrid offerings (Ulaga & Reinartz, 2011), and knowledge intensive business services (Aarikka-Stenroos & Jaakkola, 2012). This is because clients often lack sufficient knowledge and skills to diagnose their own problems and requirements, and prescribe optimal solutions (Tuli et al., 2007; Aarikka-Stenroos and Jaakkola, 2012). However, extant research tends to look at successful cases of advice taking where it is often assumed advice is taken, and most focus on large organisational clients who are expected to behave rationally. Accordingly, current literature offers very little insights on cases where and reasons why professional advice is not taken, especially in the context of SBOs, who might behave differently to large organisations. From a PSA perspective, extant literature recommends suppliers go beyond articulated customer needs and diagnose broader problems (Tuli et al., 2007; Aarikka-Stenroos & Jaakkola, 2012). While this approach addresses potential rejection reasons that relate to rational business problems (Terho et al., 2012), it does not take into account more social or psychological reasons that may relate to the rejection of professional advice in the SBO-PSA dyad. In addition, wat is currently known about taking and not taking professional advice focuses mostly on factors that influence decision-making, and there are almost no theories that address or explain the reasons for the phenomenon (Bonaccio and Dalal, 2006). That is, government reports, statistics, and academic literature demonstrate the existence of a practitioner-based problem, the phenomenon of advice rejection is under-explored in academic literature, and what is known about how advisers manage it is limited. By answering the research questions, this study will fill a gap in the literature and contribute new knowledge to a practitioner-based problem.
To ensure the most suitable methodology for answering research questions was applied, a detailed evaluation of research design options was conducted. Given advice rejection in client-adviser relationships is an under-explored topic, we applied an inductive grounded theory approach, which focused on developing novel theoretical insights from empirical observations (Corbin and Strauss, 2015). To capture the lived experiences of individuals, we conducted interviews with 32 SBOs and 20 PSAs, which collectively provided insights into more than 175 different client-adviser relationships. A dyadic approach to data collection enabled us to capture rich and complementary insights into the rejection reasons and advice facilitation strategies from both a client and adviser perspective. We analysed data using a systematic grounded theory coding approach, which included open, axial, and selective coding stages, and four levels of conceptual analysis to bring the emerging findings to life (codes, themes, categories and dimensions). To increase the credibility and validity of emerging findings, we used theoretical saturation, member checking, and multiple forms of triangulation (Farquhar et al., 2020).
Findings revealed six key reasons why SBOs do not take professional advice, six matching strategies that are used by PSAs to mitigate those reasons and facilitate advice uptake, and three dyadic tensions that exist between SBOs and PSAs. Analysis highlighted a dimension that is dyadically shared between client and adviser, namely that the reasons given, strategies used, and tensions experienced are categorically client-related, adviser-related or engagement-related. More specifically, our data revealed six reasons that relate to (i) belief prioritisation; (ii) emotional paralysis; (iii) adviser (un)suitability; (iv) advice (un)suitability; (v) lack of empathy; and (vi) missing personal landscape. Findings showed client’s often act upon their beliefs and transient emotions, measure adviser and advice suitability through fit and expectations, want their needs to be understood and met empathetically, and for personal implications to be recognised. Further, our data uncovered six matching strategies that are used by PSAs use to mitigate SBOs advice rejection and facilitate uptake, which relate to (i) contextual framing; (ii) disarming emotion; (iii) demonstrating relatability; (iv) customising advice; (v) showing empathy; and (vi) recognising the landscape holistically. Findings showed strategies are used to frame advice around client beliefs and intercept negative emotion, demonstrate personal and professional relatability to convey suitability, and express empathy and recognition by showing concern and evaluating their landscape holistically. In addition, our data revealed three dyadic tensions that exist between SBOs and PSAs which relate to (i) emotionalising vs rationalising; (ii) casualising vs professionalising; and (iii) personalising vs commercialising. Shedding light on the research questions, tensions explained how reasons manifest in the first place and why strategies used to mitigate those reasons are effective (because they reduce tension felt by SBOs).
This study contributes to contemporary B2B and services marketing literature by developing an empirically grounded dyadic framework that identifies the key reasons why SBOs do not take professional advice, the matching strategies used by PSAs to mitigate advice rejection and facilitate advice uptake, and the dyadic tensions that exist between SBOs and PSAs. Extant literature has focused mostly on successful cases of advice taking and large organisational clients (Tuli et al., 2007; Aarikka-Stenroos & Jaakkola, 2012); strategies that facilitate customer participation and educate clients on advice-taking benefits (Chan, 2010; Ulaga and Reinartz, 2011); and how tensions impact organisations and can be alleviated to improve profit and performance-driven outcomes (Toth et al., 2018; Mundy, 2010). In contrast, findings provide new insights that explain why unsuccessful cases of advice taking occur and how advice and advisers are perceived by smaller organisational clients; how strategies that mitigate and manage emotion and personal needs are necessary beyond consumer decision-making and required in a B2B context; and how tensions in client-adviser relationships impact individuals personally and professionally. Contributing to managerial practice, the strategies, reasons, and tensions identified provide lessons learnt from a wide range of business types and professions, and insights that are useful to both SBOs and PSAs.</p
Recovery of Bio-energy and Resources from Organic Waste Streams in Established Trade Waste Customers
No full textIndustrial wastewater, also known as trade waste, can vary widely in its contents, properties, and volumes.
Depending on the industry sector and internal processes of a business, each trade waste stream is unique.
Organic compounds, acids, bases, metals, sulphur substances, herbicides, hydrocarbons, biologically
active agents, and pathogens are some components that may be present in the liquid waste produced.
These aspects mean that the uncontrolled release of trade waste can result in human health effects and
environmental damage. To limit this damage, wastewater in metropolitan catchments is treated both on-
site and in centralised treatment plants. In operating treatment plants, municipal water service providers
monitor and collect data on the effluent as it leaves a business and set restrictions on discharge quality.
This data is used as the basis of service fees, and fines can be levied for breaches, so on-site treatment
before the point of discharge is incentivised. Unfortunately, this is seen primarily as a cost and a burden,
with common treatment methods including neutralisation, destruction, and separation of restricted
substances for disposal in landfill. This approach can be costly and a drain on resources, as well as only
postponing or relocating environmental impacts. An alternative perspective on treatment sees trade waste
as an opportunity, and the otherwise unwanted contents as valuable resources to reclaim through various
specialised techniques, closing the loop of a circular economy and minimising greenhouse gas emissions.
In particular, anaerobic digestion can convert organic compounds to biogas: a mixture of methane and
other gases than can be used directly as a fuel or processed and sold.
Resource recovery, despite the potential benefits, is less common at individual trade waste sites than
traditional treatment techniques. To achieve sustainability goals and better water quality outcomes, it is in
the interest of water service providers to assist trade waste customers in exploring the possibilities of
resource recovery. The historical discharge data held by water corporations is seen as a possible key to
identifying businesses who can shift to using anaerobic digestion to treat effluent. However, it is currently
unknown how well this data translates to suitability for anaerobic digestion. Considering this unrealised
potential, the broad objective of this work is to examine the plausibility of identifying targets for anaerobic
digestion at established trade waste customers by understanding a service provider’s catchment.
In the literature review, a holistic overview of resource recovery from industrial wastewater is presented.
Generalised characteristics of effluent from different industry sectors are summarised, as well as example
limits for certain factors. This literature review highlights various technologies and processes in the resource
recovery space and evaluates their advantages and disadvantages. Proposed methods of classifying trade
waste are also described. A research gap surrounding the efficacy of these schemes in identifying resource
recovery prospects is identified, as they mostly remain theoretical, with actual implementation rare.
Literature that focuses on the interactions between water service providers and their industrial customers
regarding resource recovery wastewater treatment decisions is minimal and suggests hidden areas of1
opportunity. Although certain water chemistry parameters are readily measurable and identified by industry,
the microbiome of trade waste, and the effects caused by non-biological treatments, is less clear.
To answer whether data held by water utilities can be used to identify prospects for anaerobic digestion, a
broad initial screening study was completed in Chapter 2. Several sites were selected, and pre-treated
wastewater samples, corresponding to the historical data held by water service providers, were taken.
Where possible, untreated samples were also obtained from the same sites, to give comparisons.
Biomethane potential assays were carried out using these samples to find the quantity of biogas that may be
possible to produce from the wastewater at each site. Methane yields varied between sites, reaching up to
357 mL/g VS for untreated waste, and 287 mL/g VS for treated waste. In general, at each site, raw
wastewater that had not undergone any treatment yielded more methane than the discharge-ready treated
trade waste. The historical data did not always reflect the actual composition of the treated effluent and had
minimal and inconsistent correlation with the properties of untreated samples, a result of different trade
waste customers utilising different treatments to different extents. Therefore, historical data was not a
reliable indicator of anaerobic digestion potential, although a history of high sodium levels is likely to
preclude suitability.
Another aspect of the differences between samples across sites and treatment levels is the microbes found
within them. With the aim of taking an inventory of microbes in trade wastes, and uncovering any links it has
with treatment, industry, and suitability as anaerobic digestion substrate, Chapter 3 provides a snapshot of
the microbial communities of the wastewaters studied previously. Using amplicon-based sequencing,
unique taxonomy was found across the catchment. Treatment levels, industry, and gas yields were not
found to be directly related to the original microbes present in a sample. Diversity varied between samples,
with a slightly higher number of taxa found in treated trade waste when compared to the untreated
wastewater at most sites studied. Although ultimately not directly applicable in a resource recovery context,
this section provides a valuable record of microbes present in industrial wastewater.
In finding that untreated wastewater can produce more biomethane, a new question is raised: are there
internal waste streams that biological treatment can be concentrated on with positive effects? Chapter 4
consequently progresses to semi-continuous digestion of an internal waste-stream from a site identified as
potentially suitable for anaerobic digestion, and its co-digestion with another high-yielding sample in the
presence of a biosolids biochar additive. In this work, the suitability of source-separated strong waste
streams was investigated, as well as considerations around interpreting BMP results in the context of
practical applications, and microbiological and chemical changes as a digestion proceeds, particularly
biogas production and volatile fatty acid accumulation. Process stability was found to be possible, with
lower VFA accumulation and higher yields (0.43 L day-1 L-1 and 0.24 L day-1 L-1 of methane at 45 and 30 d HRT
respectively) at a longer retention time. The microbial community shifted in similar ways between retention
time treatments, and diversity of the microbes found in the reactors decreased over the course of the study.2
Methanosarcina was identified as the methanogenic genus most closely linked to overall methane
production within this setup. The negative effect on process stability caused by changes in feed was also
shown, emphasising the importance of process control.
This work shows that historical data held by water service providers are only a small part of identifying
suitable prospects for resource recovery processes. As this information is collected after the on-site
treatment that works in competition to anaerobic digestion, and even then, does not capture all aspects of
the water chemistry, it does not perfectly identify the potential for biogas production, an assumption
unconfirmed until this work. In addition to this, certain source separated streams within a business may be
even more suitable for digestion than the total combined effluent, shown in the later section of this thesis.
As the presence of these fractions is masked by aggregation and on-site treatment, a more individualised
approach is required, with examining high-level data only a first step. Biomethane potential tests
oversimplify process design and control issues, so individual studies must also progress from batch tests to
testing that more closely matches the final plant configuration through scale-up. Through closer
examination of trade wastes, this work additionally provides a novel identification of the microbial ecology
of various treated and untreated industrial wastewaters, and the dynamics of digesters using these
substrates.
Existing trade waste customers have been shown by this work to be a valid target when exploring anaerobic
digestion as a resource recovery-focused wastewater treatment process, with potential benefits to circular
economy and greenhouse gas emissions.</p
Tyre Waste to Wealth: Sustainable enhancement of polymers
No full textMost of the world’s transportation relies on vehicles, and tyres are an essential part of most of them. To meet the world's requirements, tyres must be manufactured continuously, as they have a finite lifespan. Every year, more than one billion tyres are discarded globally, and 60-65% go to landfills or are used for illegal stockpiling. This poses severe health risks and fire hazards and release of toxic gases that pollute air, water, and soil. Pyrolysis has been proven to be one of the eco-friendly solutions for treating tyre waste and it delivers four products: oil, char, steel, and gas. However, pyrolysis plants are limited worldwide for various reasons, including end-market opportunities, especially for char. Char is a carbonaceous material; refined char is called recovered carbon black (rCB). This research aims to valorise the rCB as a sustainable reinforcement in synthesising polymer composites. For this purpose, polypropylene (PP) thermoplastic polymer has been chosen to examine the mechanical properties and UV stability. These composites can be used in packaging materials, automotive parts, gardening essentials, piping, footwear, and more. Using rCB rather than commercial carbon black can reduce CO2 emissions fivefold and carbon footprints by 80%, leading to a cleaner and greener environment.</p
Vernacular Toolbox; Strategies for Modernizing Traditional Houses in Rural China
No full textThis PhD research is drawn from the reflection on my work in rural China over the past 17 years, beginning as a partnership (Rural Urban Framework with Joshua Bolchover) and from the onset of this PhD as individual and other collaborative practice work since 2016. The work examines the impact of urbanization and globalization on rural lifestyle and livelihood in China through the detailed study of adaptations made to ancestral dwellings by local builders, followed by design proposals and built prototypes to anticipate the future of the traditional house.
The research demonstrates various approaches to the contribution architects can make to the evolution of vernacular architecture or an architecture without architects (a reference to previous considerations of the topic). Through a set of diverse projects, the research reveals the equally diverse starting points I have explored for the renovation of traditional building types, resulting in strategies which address the urban, programmatic, constructional, material and detail transformations of vernacular architecture. In turn, the process of designing and building projects reveals some of the unique potentialities (and even contradictions) of the urbanization process in China. As such, it is research operating at two scales: the domestic scale detail, and the urban context, making architectural interventions which learn from and lead to a better understanding of the dynamic, rapidly changing context in which they occur.</p
Innovative Design of Fibre Reinforced Concrete Tunnel Segments
No full textTunnels have been playing a significant role throughout the history of civilisation. In recent years, precast fibre reinforced concrete (FRC) tunnel segments have been increasingly used worldwide. Compared to normal concrete, FRC has higher tensile strength, increased toughness and reduced crack, making it an ideal material for tunnel lining design. Also, as fibres can be easily incorporated into concrete mix, reinforced steel cages can be significantly reduced or even eliminated, which provides a cost-effective and environmentally friendly alternative to traditional reinforced concrete (RC) tunnel segments, and opens up an opportunity for innovative tunnel segment design. In traditional shield tunnel, segmental joints are the most vulnerable parts of a tunnel structure due to their considerably low bending capacity caused by bolted connection. Leakage is a notorious issue in tunnel structure due to joint opening, which can cause severe joint deformation and instability of lining, leading to tremendous losses of life and property. Joint opening usually occurs during long-term operation, while severe damage of tunnel segment and significant joint opening can be caused by impacts from occasional train derailments and car collision. Although substantial research has been conducted to evaluate the structural performance of FRC tunnel lining, most of the existing studies have been focused on the segments and FRC mix design only. The performance of FRC segmental joint has not been well explored. Moreover, the dynamic response of FRC tunnel lining has not been reported in literature. Consequently, it is essential to optimise FRC segmental joint design and investigate the dynamic response of FRC tunnel lining under impact loading. As an innovative design concept for developing new materials and structures, topological interlocking has great potential to be applied to optimise the geometry of precast FRC tunnel segments. Interlocking structures display a number of desirable characteristics, such as improved bending flexibility, strong fracture resistance and high tolerance to locally damaged or missing elements. In this thesis, a novel non-planar interlocking design of FRC tunnel segment is proposed to optimise the segmental joint and enhance the impact resistance of tunnel structure. Both experimental and numerical studies are carried out to investigate the performance of the new tunnel segment design, and the recommendations are also provided. A novel non-planar interlocking element is firstly proposed, which has a symmetrical geometry with six curved side surfaces to be interlocked with adjacent elements. A tunnel can be simply constructed by assembling a number of these identical elements without mortar, and the movement of each element is naturally restricted in all directions. The structural behaviour of the concrete tunnel assembled with the proposed non-planar interlocking element is investigated numerically. It is found that the interlocking assembled concrete tunnel has a lower peak contact force and a higher energy absorption capacity under impact load compared to the concrete tunnel constructed with normal segment and monolithic concrete tunnel. To further investigate the performance of the interlocking assembled tunnel made of FRC, lab-scale drop weight tests are carried out. An aluminum mould is designed to cast non-planar interlocking steel fibre reinforced concrete (SFRC) segments, making the fabrication process easy and cost-effective. To impact the inner surface of the tunnel specimen, a sophisticated test setup is proposed, and a customised steel frame is fabricated. The influences of the initial impact velocity and the confining load on the impact resistance of the interlocking assembled SFRC tunnel are examined. Furthermore, a finite element model and modelling techniques that can accurately predict the impact performance of the interlocking assembled SFRC tunnel are developed. In particular, the constitutive model for SFRC is carefully calibrated in the present model. The structural details of the experimental setup, such as the frictions and constraints between different components are considered. Once the numerical model is validated by the experimental results, a parametric study is conducted to evaluate the effect of the geometric design of segmental joint. Finally, the recommendations for the optimisation design of SFRC tunnel segment are provided.</p
Affective Dustly Becomings With Child-Earth Relations and Other Matters
No full textToday's global climate crisis, exacerbated by the COVID-19 pandemic, presents an imperative for a transformation of environmental education that promotes relations and connections with multispecies and the rest of the world. This transformation requires an extension of notions of justice. It demands new knowledges and urgent actions to alleviate a looming environmental catastrophe and respond to the devastating consequences that anthropogenic activities are causing to multispecies ecologies through climate change and pollution. Given this, it is paramount for early childhood and environmental education to adopt alternative perspectives beyond humanist thought and research.
This research study engages with the microscopic matter of dust. How does the agency of dust reciprocally affect-with child-earth relations during microscopic and mapping encounters? How do the entanglements and transformation of dust, child bodies and other matter ‘matter’ to? each other? Dust can be regarded as an agentic matter that ties us to capitalism, colonialism, and pollution, creative ecological microworlds and all forms of planetary lives. My study, situated in a kindergarten in Melbourne, Australia and using multispecies ethnography to research with dust and other bodies as participants and co-researchers, challenges current environmental education approaches. These approaches focus on child-centred and individualised educational frameworks and practices that centralise separation, such as human/nature and hierarchies between the human and the rest of the world, including the child as a knowing subject and the more-than-human as an object of inquiry. By focusing on dust, materials, equipment, atmospheric forces, child bodies and multiple others, the project critiques environmental education frameworks and how they fall short of acknowledging the agency, entanglements and complex interrelations of all matters. This thesis recognises the relations and connections between the human, the more-than-human and the rest of the world. This study has implications for pedagogical practices in early childhood education, requiring a step away from exclusive human agency to allow knowledge and experience to be co-constructed with multiple others.</p
Exploring Sustainable Housing Policy in Australia and Other Leading Jurisdictions
No full textSince the 1980s, global climate change has been the most significant environmental issue worldwide. Buildings account for up to 40% of total greenhouse gas emissions, while residential construction is the largest segment for the greenhouse gas emissions of the building industry. Therefore, researchers and policymakers worldwide have proposed sustainable housing to minimize greenhouse gas emissions from the residential sector. Leading jurisdictions like the European Union and California in the United States of America have developed regulations supporting sustainable housing, establishing international best-practice housing performance. However, by comparison, sustainable housing policy development in Australia has been limited as the current policies require more innovation, information and communication across stakeholder groups to tackle built-environment sustainability challenges. These limitations and potential barriers have decelerated Australia’s adoption of more sustainable housing deliveries. However, if the final aim of a sustainable housing transition is a housing requirement characterised by a sustainable dwelling, then establishing an appropriate policy and favourable regulatory environment is a critical step. Although some previous studies on Australia’s transition to low-carbon or low-energy housing exist, sustainable housing regulations have been updated over time. Therefore, a comparison review of the current ongoing policies between Australia and other leading jurisdictions is needed to fill this research gap. This thesis applies the policy comparison approach to investigate and evaluate the research gap, reviewing and comparing existing policies in Australia and leading jurisdictions to identify the key lessons to improve sustainable Australian housing policies. To explore the transition to sustainable housing requirements, selected policy documents were compared using a socio-technical transition framework. The policy comparison analysis process examined three case studies: Victoria, Australia; Copenhagen Denmark; and California, the United States. The discussion of the results considers improvements in the policymaking process and identifies key lessons for policy development in Australia. Drawing upon this international policy comparison review of the selected nations, recommendations for future research for Australian policy are then suggested.</p
Application of Biosolids-Derived Biochar for the Remediation of Australian Soil Contaminated with Diesel
No full textSoil contamination, an aftermath of the Industrial Revolution, is a common environmental problem in many countries, including Australia, China, and the United States. In Australia alone, 160,000 sites are estimated to be contaminated, with petrogenic hydrocarbon being one of the common contaminants. Exposure to petrogenic hydrocarbons has a direct and indirect
negative impact on both the soil and living things exposed to it. For example, the soil carbon to-nitrogen ratio can be altered when the soil is contaminated with petrogenic hydrocarbons, while humans can experience carcinogenic, haemotoxic, and many other toxicological health problems on exposure to this contaminant. Additionally, soil contamination threatens the actualisation of several United Nations Sustainable development goals, such as clean water and sanitation for all. There is an urgent need to remediate petroleum hydrocarbon-contaminated sites, considering the magnitude of this problem and its impact on the ecosystem. Several techniques exist to remediate petroleum-contaminated soils. Among the approaches, bioremediation or biological remediation stands out as a sustainable technique for the remediation of petroleum hydrocarbon-contaminated soil in terms of cost, environmental benefits, and social acceptance. However, bioremediation alone may be slow and thus unsuitable. Additives such as biostimulation (nutrients, or aeration), and bioaugmentation (microorganisms) can be
introduced to the contaminated soil to reduce the remediation time. One additive that has found relevance in recent times is a carbon-based product called biochar, which is produced by heating biomass, including waste materials, in an oxygen-limited environment, typically at a temperature of 300 - 700 oC. Its use in remediation is an opportunity to address other serious
environmental issues like waste management and climate change. Adding biochar to the soil enhances carbon sequestration through returning carbon to the soil. Also, converting waste such as biosolids and manure to biochar will reduce the volume of this waste streams and in turn lead to greenhouse gases emission reduction. The research described in this thesis aims to investigate the role of biosolids-derived biochar in the remediation of Australian soil contaminated with diesel. While the role of biochar in the remediation of petroleum hydrocarbon-contaminated soil has been investigated in other countries, the potential of biochar in the remediation of Australian soil contaminated with diesel remains unknown. Additionally, results from the literature show discrepancies in the effect of biochar on the remediation of petroleum hydrocarbon-contaminated soil, with
variation in biochar production conditions likely playing a role. The first experimental chapter of this research sought to understand (i) the effect of biochar on the remediation and ecotoxicity of Australian soil contaminated with diesel at a total petroleum hydrocarbon (TPH) concentration of 16,220 mg/kg and (ii) how the biochar pyrolysis temperature (350, 500, and
900 oC), biochar application dose (2, 5, and 10% w/w), and fertiliser dose (0, 1, and 2% w/w) influences the efficacy of biochar on hydrocarbon removal. The Taguchi design of experiment (DOE) methodology was used to design the experiment. The main finding from this chapter was that the Environment Protection Authority (EPA) Victoria maximum threshold for Category D waste (5,000 mg/kg) was achieved in the best biochar treatment (900/10/1 – pyrolysis temperature/biochar application dose/fertiliser dose). In contrast, this threshold was exceeded in the control by 2,533 mg/kg in the same incubation time. Furthermore, hydrocarbon removal was affected by treatment conditions; biochar pyrolysis temperature, biochar application dose, and fertiliser. The addition of fertiliser inhibited the efficacy of biochar in hydrocarbon removal, thus indicating that co-applying biosolids biochar with fertiliser is not recommended in the remediation of diesel-contaminated soil. To further investigate the range of biochar’s effectiveness, in Chapter 4 the efficacy of biochar was examined in soil with a higher TPH concentration (54,147 mg/kg). The treatment condition used for this chapter was as follows: pyrolysis temperature – 900 oC, biochar application dose – 5%, and fertiliser dose – 0%. The result showed that the addition of biochar led to 2,353
mg/kg lower soil TPH concentration relative to the control after 24 weeks. Although the incubation period differed from Chapter 3, the findings from Chapter 4 demonstrate that biosolids biochar can still achieve similar removal even though the TPH concentration is altered to 54,147 mg/kg. Therefore, the result from this thesis suggests that biochar effectiveness was not significantly affected when the hydrocarbon concentration was altered from 1.6% to 5.4%. The second part of Chapter 4 dealt with understanding the major mechanism since this knowledge may result in optimisation of biochar application in terms of TPH removal. To achieve this, sodium azide (NaN3), a selective bacterial inhibitor, was added to one of the biochar treatments (BN) to alter the bacterial community structure. While NaN3 has been used to study biochar mechanisms, surprisingly this is the first study to incorporate quantitative PCR and 16S rRNA sequencing. This novelty provided a new approach to studying biochar
mechanisms. After 24 weeks of incubation, hydrocarbon removal was significantly higher in the biochar treatment with NaN3 (BN) than in the biochar treatment (3,827 mg/kg more). While the soil bacterial community structure in the control and the biochar treatment were more similar at the phylum level, the biochar treatment differed significantly from the BN treatment
in terms of the composition of the bacterial community, which coincided with significant differences in hydrocarbon removal between both treatments. These findings showed that the bacterial community significantly influences hydrocarbon removal in diesel-impacted soil amended with biosolids biochar, demonstrating that biodegradation was the major mechanism.
This observation led to the final results chapter, where the effect of biochar co-application with a hydrocarbonoclastic bacterium (via immobilisation) on hydrocarbon removal on dieselcontaminated soil with a TPH concentration of 62,027 mg/kg was examined for 22 weeks. The bacterium was isolated from the BN treatment in Chapter 4 and was identified as
Ochrobactrum sp. using 16S rRNA Sanger sequencing. The results revealed that bacterial immobilisation on biochar with Ochrobactrum sp. (BIB) resulted in a statistically significantly higher hydrocarbon removal from week 10 till the end of incubation, with 5,533 and 1,607 mg/kg higher removal in BIB than the biochar treatment at week 10 and 22, respectively.
Overall, this suggests that the co-application of biochar (via immobilisation) with the bacteria was beneficial in enhancing the remediation of petroleum hydrocarbon-contaminated soil, especially at week 10. Another key finding from this study was that BIB was less effective in hydrocarbon removal when combined with fertiliser, demonstrating the non-beneficial role of
fertiliser in the soil used in this study. As the residual total petroleum hydrocarbon (TPH) concentration does not truly give an
indication of soil ecotoxicity, soil toxicity was carried out in Chapters 3 and 4, using the Microtox assay. The results revealed that biochar application generally led to reduced soil toxicity relative to the control. For example, in Chapter 4, the biochar treatment significantly reduced soil toxicity, while the control was not able to cause a significant reduction in soil
toxicity after 24 weeks of incubation. This research has demonstrated the efficacy of biochar in the remediation of Australian dieselcontaminated soil and has shown that: (i) biochar has a potential for remediation and reducing the ecotoxicity of Australian soil contaminated with diesel; (ii) the efficacy of biochar in remediation is affected by the biochar pyrolysis temperature, biochar dose, and fertiliser dose; (iii) altering the hydrocarbon concentration from 1.6% to 5.4% does not have a significant
influence on biochar efficacy in remediation (iv) biodegradation was the major mechanism in biochar-based remediation; (v) ecotoxicity should be integrated with the hydrocarbon concentration in assessing the success of remediation; (vi) the immobilisation of bacteria on biochar resulted in higher hydrocarbon removal than the sole biochar or bioaugmentation
treatment; and (vii) fertiliser was detrimental for hydrocarbon removal when it was co-applied with bacteria immobilised biochar.</p
Conservation of Caladenia (Orchidaceae) under a Changing Climate
No full textThe Orchidaceae is one of the most diverse and threatened plant families globally, with almost 3.5% listed as threatened and many more being data deficient likely underestimating the number of the threatened orchid species. This is partly due to their reliance on Orchid Mycorrhizal Fungi (OMF) for germination, growth and further development and their complex environmental niches and microsite requirements that make them sensitive to environmental change. Climate change is a major, and overlooked, threat to orchids, with only 17% of International Union for Conservation of Nature (IUCN) listed species considered under threat by climate change.
Re-introduction and translocation are common conservation practices utilised in threatened orchid management and recovery plans. However, their effectiveness is widely debated, with many re-introductions and translocations failing to produce self-sustaining populations. Furthermore, there are limitations to success at each stage of the re-introduction/translocation process; for example: poor in-vitro germination success, poor survival rates when transferred to pots or poor survival rates after re-introduction. The low success varies case-to-case but is likely a result of a lack of consideration for the specific microsite conditions for the orchid and its OMF. This thesis presents novel approaches to improve conservation outcomes in Caladenia (and possibly other orchid) species by improving our understanding of microsite condition in situ, including environmental responses, to inform the re-introduction/translocation process with future climate predictions in mind.
Long-term (12 years) vital rates of wild, re-introduced and translocated populations of the endangered terrestrial orchid, Caladenia amoena (Charming Spider Orchid), were compared, which demonstrated that re-introduction and translocation were insufficient at establishing self-sustaining populations during the 12-year study period. When relating vital growth rates to climate, emergence and flowering declined as mean maximum temperatures rose, whereas flowering increased with rainfall. Both emergence and flowering were positively correlated with the length of the growing period, which decreased by >33% during the study, highlighting it as a key concept and possibly the biggest challenge in preventing further population decline.
Similar negative correlations between emergence and flowering and temperature were observed in endangered Caladenia robinsonii (Frankston Spider Orchid), suggesting declines will continue given the current predictions of +1 to +3°C of warming by 2051 at its only known location. Using Principal Components Analysis (PCA) and General Linear Modelling (GLM) to compare soil properties and vegetation characteristics among re-introduced and wild populations identified greater nitrate concentration, graminoid cover and canopy tree distance and an open small shrub layer as common characteristics in the better performing populations.
Understanding in-situ conditions of C. robinsonii helped to improve in-vitro germination and identified three critical factors for germination, namely conducive conditions, ‘ready-to-germinate’ seed and effective mycorrhizal fungi. The positive effects of warm stratification on germination and seedling development were demonstrated for the first time, more than tripling germination and stage 4 seedling development compared to non-stratified seed. When comparing germination and OMF growth, there is a narrow overlap between the most favourable conditions for the orchid seed and OMF growth and only within this overlap can most seeds germinate and seedlings develop.
Elucidating OMF responses to climate was investigated using real-time polymerase chain reaction (qPCR) and a Serendipita-specific primer (C. robinsonii’s OMF). Soil abundance of Serendipita changed with season but not in response to mean monthly maximum (MMmax) and mean monthly minimum (MMmin) air and soil temperature or mean monthly (MM) rainfall. Serendipita OMF abundance in soil was less in declining populations than in stable/increasing populations. This is the first study to investigate the response of a free-living OMF in soil to seasonal variation in OMF abundance and soil moisture, temperature and rainfall, and suggests that the predicted changes in temperature and rainfall will probably not directly affect this free-living OMF. If free-living OMF abundance is not expected to be impacted by climate, focus should be given to other factors such as microsite conditions, particularly those favourable to in-situ recruitment, which is essential for establishing self-sustaining populations and to halt declines.
Microsite factor differences between recruiting and declining clusters of C. robinsonii were investigated using a variety of statistical methods including linear regression, GLM and PCA. Soil moisture, ground cover and OMF abundance were important factors for seedling recruitment. A soil OMF abundance of ≥1.5 ng μL-1, bryophyte cover of 60%, Banksia marginata leaf litter cover of 5-10% and a soil water content of 6-8 VWC were favourable to establishment. These results provide key factors that should be considered when choosing future re-introduction sites and during the management of existing C. robinsonii populations.
The works presented in this thesis provide novel insights that advance the field of orchid conservation in Australia and the world. The current re-introduction methods for C. robinsonii and C. amoena have not been successful at establishing self-sustaining populations. Our new understanding of re-introduced C. robinsonii populations in situ has led to improved in-vitro germination (increases up to 37% in plant numbers for re-introduction) and new on-ground management tools which could greatly improve the chances of halting population declines. Furthermore, this research could be transferrable to other Caladenia species and potentially other orchid genera.</p