Faculty of Engineering 2

Doctor of Philosophy

ABEYKOON, A Gedara Tharindu Bhagya Bandara

Thesis Title

Developing an Economical and Reliable Real-Time Warning System for Rainfall-Induced Individual Landslides

Supervisors

• Associate Professor Weerawickramage Prasanna Egodawatta (Associate Supervisor)
• Associate Professor Chaminda Gallage (Principal Supervisor)
• Associate Professor Jessica Trofimovs (Associate Supervisor)

Citation

This project was a step forward in developing a reliable, economical and accurate real-time warning system for rainfall-induced individual landslides based on physical-based, optimised slope monitoring and statistical and numerical approaches. The physical-based system involved experimental and numerical analyses in implementing a low-cost slope monitoring system in critical slopes in North Maleny, evaluating parameters of tilt angle (and tilt rate), the volumetric water content of soil and rainfall. The thesis further investigated auxiliary landslide prediction approaches, including rainfall intensity–duration thresholds and analytical time to failure predictions to enhance the accuracy and reliability of outcomes.

ARUN, Ashutosh

Thesis Title

A Novel Road User Safety Field Theory for Traffic Safety Assessment Applying Video Analytics

Supervisors

• Associate Professor Ashish Bhaskar (Associate Supervisor)
• Professor MD. Mazharul Haque (Principal Supervisor)
• Professor Simon Paul Washington (External Supervisor)

Citation

This thesis introduces a new Road User Safety Field Theory to proactively assess traffic safety by studying the interactions of various road users at signalised intersections. The proposed theory combines road traffic environmental factors, vehicle capabilities and personal characteristics to determine the extent and strength of road users’ safety ‘bubble’ or field across various traffic interactions. By applying the Artificial Intelligence-based video data analytics, the proposed Road User Safety Field Theory is found to better estimate crash risks in terms of crash frequency and severity than traditional traffic conflict techniques.

AZMAN, Mohd Azrai Bin

Thesis Title

Diversification, Institutions, and Productivity Performance of Large Construction Firms in Malaysia

Supervisors

• Dr Ka Hung Hon (Principal Supervisor)
• Associate Professor Boon Liat Lee (Associate Supervisor)
• Adjunct Professor Ronald Martin Skitmore (Associate Supervisor)
• Associate Professor Bo Xia (Associate Supervisor)

Citation

This research investigated the relationships between diversification strategies and productivity of large construction firms in Malaysia. The Generalised Method of Moments was adopted for modelling the impact of diversification strategies on productivity. The research revealed that product and market diversifications affect long-term productivity by altering firm efficiency in managing resource allocation. However, the effectiveness of diversification strategies depends on the changes in formal institutional dimensions and informal context of ownership concentration. The research findings will help construction firms to take into account the effects of institutional contexts when formulating their optimal diversification strategies for better firm productivity.

GNANACHELVAM, Sayilacksha

Thesis Title

Fire and Energy Performance of Cold-formed Steel Frame Wall Systems

Supervisors

• Dr Anthony Deloge Ariyanayagam (Associate Supervisor)
• Professor Mahadeva Mahendran (Principal Supervisor)

Citation

This research investigated the fire and energy performance of cold-formed light-gauge steel-framed (LSF) wall configurations and proposed suitable methods to improve their combined fire and energy performance through the incorporation of (1) appropriate fire-resistive and energy-efficient building materials and (2) modifications to the arrangement or configurations of walls. This research has advanced the current knowledge of both fire and energy performance of LSF walls, paving the way for the development and use of alternative materials and LSF wall configurations.

JAYASUNDARA, Walpola Kankanamalage Nirmani

Thesis Title

Damage Detection of Arch Bridges Using Vibration Characteristics and Artificial Neural Network

Supervisors

• Professor Hung Tin Tommy Chan (Associate Supervisor)
• Dr Andy Nguyen (External Supervisor)
• Professor David Pathmaseelan Thambiratnam (Principal Supervisor)

Citation

This project developed a method to detect, locate and quantify damage in arch bridges using variations in their vibration characteristics and artificial neural network. The method was successfully tested on a few real-life arch bridges. Outcomes of this project will contribute towards the safety of our bridges.

MADANI, Sepideh Sadat

Thesis Title

Investigation of Charge Transport Metal Oxides for Efficient and Stable Perovskite Solar Cells

Supervisors

• Professor Nunzio Motta (Associate Supervisor)
• Dr Tuquabo Tesfamichael (Principal Supervisor)
• Professor Hongxia Wang (Associate Supervisor)

Citation

This research investigates various thin-film metal oxides as charge transport layer for improving the performance and stability of perovskite solar cells. Physical Vapor Deposition techniques such as magnetron sputtering, and electron beam evaporation were used to fabricate the metal oxide thin films. The structural, morphological, chemical, optical, electrical, and electronic properties of the films were studied. Solar Cell Capacitance Simulator was employed for investigating the performance of the PSC using the experimental data as input parameters. Results showed that optimized properties of the metal oxide thin films as charge (hole) transport layer have improved the performance of the PSC device.

MATARAMBA KANKANAMGE, Kasun Dilhara Wimalasena

Thesis Title

Evalutate the Performance of Geosynthetic Reinforced Subgrades Under Monotonic Loading

Supervisors

• Associate Professor Chaminda Gallage (Principal Supervisor)
• Dr Yilin Gui (Associate Supervisor)

Citation

A series of large-scale pavement model tests were conducted in a laboratory environment to investigate the effect of geosynthetics in improving the modulus of weak subgrades. Then, a series of supplement design charts that could be useful for industry practitioners to design geosynthetic reinforced flexible pavements were developed. The outcomes of this study promote the use of geosynthetics in road construction to make economical, environmentally friendly, climate resilient, and sustainable road infrastructure.

MIRI, Amin

Thesis Title

Mitigating Severity of Longitudinal Interaction of Rail-Track-Bridge System in Transition Zones for Safer Trains

Supervisors

• Professor Hung Tin Tommy Chan (Associate Supervisor)
• Professor David Pathmaseelan Thambiratnam (Principal Supervisor)
• Mr Bill Weston (External Supervisor)

Citation

Extreme heat and temperature fluctuation in Queensland result in buckling of railway tracks which jeopardize the safety of train operation and cost huge sums to repair. This thesis carried out an elaborate investigation on the issue of track buckling and provided several approaches to mitigate the risks of track buckling to enable safer trains and lower maintenance costs for railway operators in Australia.

NIKAGOLLA, Chandima Madhubashi Nilanthika

Thesis Title

Developing Low Cost Water Treatment Solutions for Rural, Less Advantaged Communities

Supervisors

• Professor Leslie Anthony Dawes (Principal Supervisor)
• Professor Graeme John Millar (Associate Supervisor)

Citation

This research developed new knowledge relating to the provision of affordable drinking water. An integrated approach for groundwater characterisation in complex environmental settings was successfully developed and tested. A novel sorbent for fluoride removal was introduced, and a cost-effective household-level water filter was designed. The generic outcomes of this research can be applied to improve the lives of people in disadvantaged rural settings by improving their treated drinking water access.

PANAMBARA ARACHCHILLAGE, Sewmini Ravihari Jayatilake

Thesis Title

Modelling Cell-Based Quality of Service and Capacity in Bus Rapid Transit Station Platforms

Supervisors

• Associate Professor Ashish Bhaskar (Associate Supervisor)
• Associate Professor Jonathan Michael Bunker (Principal Supervisor)
• Dr Marc Philipp Miska (Associate Supervisor)

Citation

This research identifies highly congested areas in Bus Rapid Transit (BRT) platforms and apply measures to improve Quality of Service and capacity. It developed a novel model that partitioned BRT platforms into cells and examined passenger activities to evaluate variation in area available per passenger across the platform. It was identified that areas available for stationary and circulating passengers in a platform cell differed significantly. BRT platform operation during the COVID-19 pandemic was evaluated. Significant variations exist in waiting passenger distributions between the Before COVID-19 and During COVID-19 cases.

PANCHETI, Jashnav

Thesis Title

Fire Resistance of External Light Gauge Steel Framed Wall Systems

Supervisors

• Dr Anthony Deloge Ariyanayagam (Associate Supervisor)
• Professor Mahadeva Mahendran (Principal Supervisor)

Citation

This research investigated the fire resistance of external light gauge steel framed walls with autoclaved aerated concrete panels, corrugated steel and brick veneer cladding using detailed experimental and numerical studies. Along with important thermal properties and the behaviour of claddings exposed to fire, fire resistance levels and energy efficiency ratings of these external walls and the influence of many parameters are presented, which will enable efficient and safe designs. Overall, this research has significantly enhanced the knowledge and understanding of the behaviour and design of external light steel walls with different cladding materials exposed to external or internal fires.

ROSS, Maureen Therese

Thesis Title

Novel Imaging and Bioprinting Approaches for Auricular Cartilage Regeneration

Supervisors

• Dr Mark Colin Allenby (Associate Supervisor)
• Dr Sean Keiran Powell (Associate Supervisor)
• Dr Jiongyu Ren (Associate Supervisor)
• Associate Professor Maria Ann Woodruff (Principal Supervisor)

Citation

The focus of this thesis was to advance the methods and knowledge of the field of biofabrication by applying its techniques to improve current ear reconstruction for the congenital condition microtia. Three key areas were explored: advanced large format histology methods for deeper characterisation of the native cartilage tissue; a low-cost method of 3D imaging using ultrasound to capture patient anatomy; and novel multi-material 3D printed scaffold designs for regenerating cartilage. The novel methods developed in this work will contribute towards the future of advanced medical manufacturing for microtia as well as other patient specific implants.

SEPALA MUDIYANSELAGE, Chathurangi Madusha Randiligama

Thesis Title

Damage Detection in Hyperbolic Cooling Towers Using Vibration Characteristics and Artificial Neural Network

Supervisors

• Professor Hung Tin Tommy Chan (Associate Supervisor)
• Dr Sabrina Fawzia (Associate Supervisor)
• Professor David Pathmaseelan Thambiratnam (Principal Supervisor)

Citation

This research developed and applied a method based on vibration characteristics and Artificial Neural Network to detect, locate, and quantify damages in hyperbolic cooling towers. Hyperbolic cooling towers are large structures built to have long service lives. They are subjected to temperature variations, which along with material deterioration, with age and random actions, can inflict damage to the structure. The proposed method is easy to implement and can provide early warning of damage in the cooling tower to enable appropriate remedial action and prevent its collapse. This research will contribute to the safe and efficient operation of cooling towers.

VIDINAMO, Frank

Thesis Title

An Investigation of Drying Methods, Storage Conditions and Altitude on Phytochemicals and Antioxidant Activity of Fruits

Supervisors

• Dr Sabrina Fawzia (Associate Supervisor)
• Professor Azharul Karim (Principal Supervisor)

Citation

This research investigated the impact of drying methods, storage conditions and altitude on phytochemical and antioxidant activity of tropical fruits. The results revealed that intermittent microwave convective drying (IMCD) dried samples tend to contain higher TPC, stronger antioxidant activity and longer shelf life for fruits grown at high altitude. The result also revealed that drying temperature of IMCD and convective drying drastically reduced the TFC in fruits. The outcome of this research contributes to advancing the knowledge in plant base phytochemicals as alternative natural and safe sources of antioxidants as food additives to provide protection against oxidative degradation of food.

WU, Ziyang

Thesis Title

Rational Design of Two-Dimensional Architectures for Efficient Electrocatalysis

Supervisors

• Professor YuanTong Gu (Mentoring Supervisor)
• Associate Professor Ting Liao (Principal Supervisor)
• Professor Ziqi Sun (Associate Supervisor)

Citation

In this thesis, the principal focus is the rational design and fabrication of two-dimensional (2D) nanoarchitectures, e.g., low-cost metal oxide nanosheets and earth-abundant transition metal layered double hydroxides (LDHs) for enhanced electrocatalysis. The related hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance not only demonstrated the advances of 2D nanomaterials, such as unique physical and mechanical properties, unprecedented electronic features, and ultrahigh surface areas but also indicated the possible mechanisms behind boosted activity and stability, e.g., phase engineering function and oxygen vacancies influence.