A shrimp disease, known commonly as Early Mortality Syndrome (EMS), has been a major problem for shrimp aquaculture in Southeast Asia due to its epizootic prevalence within the region since it was first reported in 2009. In this study, Bacilli strains isolated from coral mucus were tested for antagonistic effects against quorum sensing and the causative pathogen. Phenotypic characterisation was carried out, including bacilli biofilms characterisation, temperature-growth responses and biosurfactant production. Three phenotypically distinct strains showing notable potential were chosen to undergo coevolution as a method for strain improvement via long term exposure to the pathogen.
Interpretative phenomenological analysis was used to explore the experience of adolescent sibling bereavement and its impact on adolescent development and psychological wellbeing in fifteen individuals (10 females and 5 males) who experienced the loss of a sibling when aged between 14 and 25 years. Analysis of data revealed themes such as: traumatic loss; disenfranchised grief; impact on identity development and developmental milestones; the family’s response to loss; and loss as a crisis and growth. The results of this study will assist the identification of supporting factors and resources for professionals, families and friends supporting sibling bereaved adolescents.
Grain hardness or texture is a commercially important trait that governs the end use of wheat. The variability in grain texture enables the production of different food products and eating qualities. Similarly, grain texture affects malting and processing quality of barley with relevance to its end-use. This study investigated the grain hardness genes of Australian wheat and barley cultivars. Worldwide landraces were also investigated for gene diversity. Novel genetic variation was identified and several findings were made that might enhance our understanding of the relationship of these genes with grain texture.
This thesis contributes to the thermal energy storage enhancement of buildings with the application of phase change material (PCM) integrated cementitious composites. Two major issues hindering the widespread usage of PCM in cementitious composites were identified as instability or leakage of PCM and poor heat transfer rates due to their low thermal conductivity. This study developed a novel PCM composite to overcome these issues and promising results were achieved. The experimental and numerical study on the developed PCM composite integrated cement-based materials showed significant enhancement in thermal energy storage and thermal performance of buildings without associated leakage issues.
Optical technology offers an environmentally-friendly, energy-efficient solution for managing big data. Information can now be encoded onto angular momentum (AM) of light which offers an additional degree of freedom that could significantly boost the bandwidth of optical technology. We developed a nanophotonic chip consisting of an array of nano-waveguides that could offer unparalleled levels of control over the AM of light at a nanoscale, leveraging the use of a tiny photonic device for parallel AM information processing. Our work opens up exciting avenues for on-chip AM applications like ultrahigh-definition displays, ultrahigh-bandwidth communications, ultra-secure optical encryptions, and highly-sensitive biological sensing.
Anomaly detection is the identification of events or observations that do not conform to an expected behaviour of a system. The lack of detecting anomalous items could translate to some kind of problems such as system failure, network intrusion, frauds, etc. This thesis addressed some of the challenges in this domain by proposing a set of mechanisms to perform a cross-layer anomaly detection using correlation analysis of systems’ logs and metrics. The result of investigating with two complex case studies demonstrate that the proposed techniques were able to detect emulated anomalies with high accuracy.
This research explores a new asphalt mix design methodology to facilitate implementation of the perpetual asphalt pavement design concept in Australia. By achieving perpetual status, pavements will only require periodic resurfacing without experiencing any major structural deterioration. This translates to significant cost savings in construction and rehabilitation of flexible pavements by providing a longer service life for the road assets and minimising user delays.
Test suite based automated program repair aims to automatically fix program bugs. This thesis applies metamorphic testing concepts to address three challenging problems in test suite based automated program repair, including the alleviation of the test oracle problem, the generation of effective input test suites, and the development of an innovative repair method. The application of the proposed approaches has been demonstrated to be able to extend the scope of applicability for test suite based automated program repair and improve its repair effectiveness, which thus increases the practical benefits of automated program repair techniques in assuring software quality.
Molten alkali nitrate salts as a heat transfer and storage fluid is promising in concentrated solar power plants because of their negligible vapor pressure and optimum fluid velocity. A ternary sodium-potassium-lithium nitrate salt has been proposed using a thermo chemical package, which has low melting point (120.8°C) compared to binary solar salt (220°C). The purpose of this study is to increase the degradation limit of proposed ternary salt using oxygen as a cover gas to obtain broader operating temperature range (to increase the steam-Rankine cycle efficiency) and for potential use in thermal energy storage systems as a heat transfer fluid.
Biomass fuels are treated as CO2 neutral energy source which can be co-fired with coal to decrease the total costs of power production. Utilization of these fuels increases the possibilities of slagging and fouling risk. To better understand and thus improve the design for co-firing and slagging in wall-fired furnace, a computational model has been developed for predicting the co-firing scenario, emission level, slag formation mechanism under air/oxy-fuel conditions. It was predicted that 20% biomass can be co-fired with coal in industrial power plant. The pollutant emissions can be significantly reduced by using oxy-fuel combustion technique which provides equivalent heat transfer performance.