18397 research outputs found
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Ultra-High Temperature Ceramic Coatings for Hypersonic and Space Applications
No full textThe next generation of hypersonic crafts will revolutionize air and space travel. However, these vehicles will encounter severe environments in operation, especially extreme temperatures. Thermal protection system coatings that can withstand the high temperatures experienced and rapidly conduct heat away from at-risk regions provide the required protection to allow these craft to sustain extreme hypersonic velocities. Refractory boride materials and silicon carbide were investigated as candidate materials for such coatings. Coatings were deposited using the plasma spray technique and inspected in an effort to produce thermal protection system coatings capable of protecting the next generation of hypersonic craft
Modelling and Optimisation of Solar Thermal Waste to Fuel Pyrolysis for Increased Daily Production
No full textAs the world’s population grows, so too will the amount of waste it produces. This will occur mostly in the form of municipal solid waste, of which low and high density polyethylene will make up a large portion. Solar thermal pyrolysis offers a sustainable way of breaking down this polyethylene waste into commercially valuable upgraded waste fuel. Periods of low solar exposure reduces the amount of waste that can be converted into fuel. This research focussed on modelling and optimising solar thermal pyrolysis to account for this solar intermittency and make it more economically viable process
Crashworthiness of functionally graded and bio-inspired tubes
No full textLightweight structures are material-efficient, environmentally-friendly, and have been extensively used in various applications including cars, trains, ships and planes. These structures are expected to possess good energy absorption performance in service to protect either human from being injured or structural components from being damaged. Thin-walled circular, square and hexagonal tubes have been considered as good energy absorbers over the past several decades. However, their energy absorption capacity can be further improved. Therefore, this work is dedicated to developing and investigating thin-walled tubes with enhanced crashworthiness
Apparatus for Creating Big Time Crystals Based on Bouncing Ultracold Atoms
No full textThis thesis describes the design and construction of a dedicated optics apparatus to create a new state of quantum matter, a time crystal. Time crystals are a quantum-physics related phenomenon in which a periodically driven many-body system, such as a Bose-Einstein condensate of ultracold atoms, spontaneously self-reorganises its motion so that it evolves with a period longer than the driving period. These systems are predicted to reveal novel condensed matter phenomena in the time domain. Possible practical applications of time crystals include quantum information processing, sensitive magnetic field sensors and atomic clocks
Study of Black-Silicon Thermophotovoltaics for Waste-Heat-to-Electricity Harnessing via Novel Fundamental Modeling
No full textIn this research, simulation studies have been done to study the use of photovoltaic cells in thermophotovoltaic applications. In simple terms, thermophotovoltaic devices convert light and heat energy to electricity. They are significant for the conversion of waste heat as a source of renewable energy. Simulation models are important for engineers and scientists to identify defects in designs before/during experimental studies of prototypes. Hence, the results from this research are important in steering the direction of thermophotovoltaics and sustainable energy
Recycling and Recovery of Metals from End-of-Life Electric Vehicle Components (Lithium-ion Batteries and Rare Earth Permanent Magnets)
No full textIn recent years, the demand for electric vehicles (EVs) has significantly increased to support decarbonisation in the transportation sector. However, the increase in EVs uptake will result in a high generation of EVs components waste. The disposal of these wastes into landfills is not the solution as they have the potential to negatively impact human life and environment. Recycling is vital as one of the strategic solutions. It is also to conserve natural resources on earth. This thesis attempts to recycle and recover valuable metals from two EOL EV components, namely rare earth permanent magnets (REPM) and lithium-ion batteries (LIBs)
Basin Amplification Effects on Structures: Bridge Fragility Subjected to Subduction Earthquakes
No full textThe sedimentary basins are regions of the earth’s crust that consist of thick multiple layers of sedimentary soil deposits. With the availability of fresh water and flat terrain for ease of infrastructure, the sedimentary basins have become home the dense urbanization. Most of the densely populated cities like Mexico, Seattle, and Kathmandu located directly on basins. Due to the impedance contrast between basin and bedrock materials, these sedimentary basins often amplifies the seismic waves. One of the classic examples is 1985 the Michoachan earthquake where the Mexico City located at 350 km from the epicentre, suffered significant damage. It is also evident that the densely populated basins are in the vicinity of seismically active fault regions such as Cascadia subduction zone and Himalayan fault zone. Since the sedimentary basins often lead to amplification of the seismic ground motion, which eventually increases the consequences of earthquakes on civil infrastructure, the investigation of the basin amplification is one of the major concern issues for seismologists and earthquake engineers
Investigating the design elements of typicality and novelty to enhance the appeal of Thai souvenirs
No full textThis study examined how typicality and novelty affect the aesthetic preference for designed products. It was undertaken to promote and enhance Thai design to ensure products designed in Thailand were more competitive on a global scale. The focus was on tourism products (souvenirs) in Thailand. The product selection followed Thailand's 4.0 policy. The study found that the two countries, China and Australia, had similar preferences in terms of the metric "Pleasing to see". Conclusions suggested that product studies should focus on how aesthetic preferences for product shape affect its effectiveness as a souvenir gift for tourists visiting Thailand
Robust Disturbance Observer-based Repetitive Control for Brushless DC Motors
No full textRepetitive control (RC) is widely applied in rotational control systems including brushless DC servo motor (BLDC), since it can track periodic reference signals and reject periodic disturbances. However, RC cannot compensate aperiodic disturbances, friction, parameter uncertainties, backlash, and time delays. All of these uncertainties may lead to higher tracking errors. To overcome this issue, a series of novel RCs is developed to track the reference signal accurately and reduce the tracking error. The novel RCs can improve the performance of BLDC in hard drives, vehicles, air conditioning, robots and more. Subsequently, the efficiency is increased and the cost is reduced
Perceptual and Neural Recognition of Realistic, Dynamic, Spontaneous Facial Emotional Expressions: The 4D Space-Time Perspective
No full textThis thesis examined how progress in understanding emotional expression recognition could be improved through perceptually-realistic, dynamic, spontaneous facial expressions modelled as 4D computer human stimuli. The methodology of this thesis explored how complex facial expressions are recognised by the human visual system. The findings support emotion-specific preferences in facial recognition, while providing clarification on how the visual components of a 3D expression model are decoded through dynamic, localised facial musculature or through facial configuration. Implementing machine-learning with EEG-based neural activations, has explored how emotional expressions are decoded in higher cortical systems as perceptually-realistic expressions naturally unfold over space and time