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Polydimethylsiloxane-embedded conductive fabric for realisation of robust flexible passive and active wearable antennas
No full textTheoretical thesis.Bibliography: pages 127-142.1. Introduction -- 2. PDMS-embedded conductive fabric -- 3. Simple dual-band dual-mode wearable antenna based on PDMS-embedded conductive fabric -- 4. UWB wearable antenna with full ground plane based on PDMS embedded conductive fabric-- 5. Realising robust flexible electronically tunable antennas using PDMS embedded conductive fabric --6. Conclusions and future work -- Bibliography.This thesis presents polydimethylsiloxane (PDMS)-embedded conductive fabric as a new approach to realise robust flexible wearable antennas. The approach combines the use of conductive fabric as the antenna radiator and ground plane, with PDMS which acts as the antenna substrate and a protective encapsulation. This allows for a simple yet effective approach to achieve robust flexible wearable antennas.Initially, a thorough characterisation of the mechanical and electrical properties of the PDMS-embedded conductive fabric was demonstrated with four potential combinations of PDMS-conductive fabric considered in this thesis. This characterisation provides valuable insight into the mechanical robustness of the proposed approach, the constraints associated with selection of the conductive fabric for various parts of the antenna, and the effective modelling of the antenna. Upon gathering the characterisation results, several wearable antenna designs were developed as concept demonstrations. To verify the designs, their performance was then investigated experimentally, including RF performance tests both in free space and on fabricated ultra-wideband (UWB) human-muscle equivalent phantoms, and mechanical stability tests e.g. bending tests on the aforementioned phantoms and machine-washing tests.As the first concept demonstration, four simple inset-fed rectangular patches were designed using the four combinations of PDMS-conductive fabric characterised before, thus verifying the properties obtained from the characterisation process. Next, a new dual-band dual-mode antenna design suitable for off- and on-body communication was developed as the second demonstration. Different from previously reported works, the dual-band dual-mode operation was achieved by utilising inherently generated higher order modes of a patch antenna, allowing for a much simpler design that only used a single patch fed by a simple probe feed.Further, a novel planar UWB antenna design was developed to demonstrate the applicability of the PDMS-embedded conductive fabric technique for UWB and high-frequency applications. In contrast to previously reported flexible UWB antennas, the design maintains a full ground plane which provides a high isolation between the antenna and the human body when worn. The antenna time-domain analysis in both free-space and on-body environments was also conducted, demonstrating its suitability for UWB pulse transmission.Lastly, the application of PDMS-embedded conductive-fabric technology was expanded further to cover, for the first time, the realisation of robust flexible electronically tunable wearable antennas. A frequency-reconfigurable patch antenna that can stand physical deformation and even machine-washing has been successfully developed. Its miniaturised version, incorporating a PDMS-ceramic composite substrate, was also investigated to show the versatility of the proposed PDMS-embedded conductive fabric.In all four concept demonstrations, a good agreement between simulated and measured results is shown. Consistent performance including reconfigurability was obtained even after the antennas were exposed to harsh environments, e.g. extreme bending and machine-washing. This validates the applicability of the proposed approach for realisation of robust flexible antennas for wearable applications.Mode of access: World wide web1 online resource (xxxiv, 142 pages) illustrations (some colour
A data placement approach for scientific workflow execution in hybrid clouds
No full textEmpirical thesis.Bibliography: pages 47-52.1. Introduction -- 2. Literature review -- 3. Problem statement -- 4. Hybrid scheduling for hybrid clouds -- 5. Evaluation -- 6. Conclusion -- List of symbols -- References.Cloud computing has been widely adopted by industry practitioners and researchers. Recently, applications in science and engineering such as scientific workflows have also been increasingly deployed in clouds. As these applications are becoming resource intensive in both data and computing, private clouds struggle to cope with their resource requirements. Public clouds claim to overcome many shortcomings of private clouds. However, the complete offloading of workflow execution to public clouds may introduce excessive data transfer and privacy/governance concerns. In this thesis, we propose a hybrid cloud solution for workflow scheduling explicitly considering data placement. To this end, we present Hybrid Scheduling for Hybrid Clouds (HSHC), which schedules scientific workflows across private and public clouds incorporating a novel dynamic data placement policy. HSHC consists of two phases: static and dynamic. The former uses an extended genetic algorithm to solve the problem of workflow scheduling with static information of workflows and cloud resources. The latter adjusts scheduling and data placement decisions reflecting changing conditions of workflow execution in the hybrid cloud. We evaluate HSHC with both real-world scientific applications and random workflows in performance and cost. Experimental results demonstrate HSHC’s two-phase approach effectively deals with the dynamic nature of the hybrid cloud.1 online resource (x, 52 pages) diagrams, graph
What drives isoprene in tropical Australia?
No full textEmpirical thesis."This thesis is submitted to Macquarie University and The University of Edinburgh for the degree of Doctor of Philosophy" -- title page.Bibliography: pages 201-226.1. Introduction -- 2. Site description and methodology -- 3. FIS field campaign results -- 4. Modelling with MLC-CHEM and MEGAN -- 5. Opportunities for future work.Isoprene is the dominant biogenic svolatile organic compound (BVOC) emitted from plants across the globe, with a mass of 400-600 Tg emitted annually. Its emission and chemical degradation plays a central role in the atmosphere, contributing to the formation of ground-level ozone and secondary organic aerosol.Tropical ecosystems contribute up to 75% of the global isoprene budget.Seasonal isoprene emission patterns in tropical regions remains unclear, particularly when compared to the mid-latitudes. It was hypothesised that in tropical regions, isoprene would be consistent throughout the year. However, a 12-year record of satellite observations of formaldehyde (HCHO) over the Amazon basin showed that HCHO columns reduced by 20-40% each year during the wet-to-dry transition. This thesis verifies these observations and investigates the hypothesis with a long-term, ground-based measurement study in a rainforest environment, paying particular attention to this transition period.To improve understanding of seasonal isoprene emissions patterns I conducted a measurement and modelling campaign in Far North Queensland to understand the drivers of isoprene emission in tropical Australia. A Fast Isoprene Sensor was installed in the Daintree Rainforest and I measured canopy-level isoprene concentrations over three years. They show that isoprene emissions follow a seasonal cycle, which differs from the Amazon. The measurements are compared against GOME-2B satellite observations and MEGAN and MLC-CHEM models to investigate factors driving emission patterns across several timescales.Findings show that model bias decreases by over 10% when leaf area index varies in response to the growing season and the emission factor is optimised by time and season.This is the first major BVOC study to be conducted in the Daintree, and is the first isoprene study in tropical Australia in over 20 years. The results presented in this thesis represent the first observations of seasonal isoprene emission patterns in Australia and provide an important contrast to other tropical ecosystems.Mode of access: World wide web1 online resource (xvii, 226 pages) colour illustrations, colour map
A history of transhumanism
No full textTheoretical thesis.Includes bibliographical references.Images suppressed for copyright reasons.Part 1. Proto-transhumanist ideas -- 2. Modern transhumanist movements -- 3. Why transhumanism matters -- Back matter.This thesis presents the first book-length history of transhumanism. I trace the roots of proto-transhumanist thinking back to the Scientific Revolution and explore major examples of proto-transhumanist thought up to the late twentieth century. I then chronicle the origin and evolution of the first modern transhumanist movements and ideas. Finally, I demonstrate that transhumanist ideas and technologies are now fundamental features of the modern world and argue that we should take them very seriously, as they have the potential to profoundly influence how the human future unfolds.1 online resource (414 pages : illustrations, portraits
An integrated hybrid-chip-fibre platform for the generation of mid-infrared light
No full textEmpirical thesis.Bibliography: pages 51-53.1. Introduction -- 2. Background theory of mid-infrared fibre lasers -- 3. Ultrafast laser direct inscription technique -- 4. Design, fabrication and characterisation of a fibre-pigtailed coupler for the mid-IR -- 5. Conclusion -- References.The laser is, without doubt one of the most important, discoveries that have been made in the last century and within a few decades, visible and near-infrared (IR) laser light has found a vast number of important applications in industry and research. The discovery of low-loss optical fibres was another revolutionary step that underpinned the rise of the global telecommunication industry.The mid-IR region of the electromagnetic spectrum spanning from about 2 – 20 μm, has recently been identified as a powerful tool for sensing and medical applications due to the strong and highly specific interaction of light at these wavelengths with molecules. However, while lasers based on silica-fibres have proven to be the most versatile and efficient light sources in the visible and near-IR, those glasses become virtually opaque at mid-IR wavelengths and new solutions are required. In this work, mid-infrared fibre lasers that are based on fluoride-glass optical fibres and on femtosecond laser-inscribed chalcogenide glass integrated chips are investigated. In detail, this project is aimed at studying the feasibility of fabricating a wavelength-selective 3-D integrated coupler in Gallium Lanthanum Sulphide (GLS) glass. The demonstration of the first fibre pigtailed 4-port device in the mid-infrared is a prerequisite for the future realisation of the first fully integrated mid- infrared ring laser. This, in turn, would further open the possibility to develop monolithic all-fibre mode-locked lasers that are based on non-linearly coupled waveguide arrays.Mode of access: World wide web1 online resource (ix, 53 pages) colour illustration
Sperm phenotype of admixed and ‘pure’ subspecies males in the long-tailed finch
No full textThesis by publication.Bibliography: pages 42-50.Reproductive isolation is central to the speciation process. Recent research suggests that where heterospecific mating occurs, postmating prezygotic (PMPZ) barriers and hybrid infertility can act as powerful reproductive barriers. Two traits that may underlie PMPZ isolation and reduced hybrid fertility are sperm morphology and motility. The two subspecies of long-tailed finch (Poephila acuticauda acuticauda and P. a. hecki) offer an excellent opportunity to investigate mechanisms of reproductive isolation as their narrow hybrid zone in the wild suggests incomplete reproductive isolation, and they can be studied in captivity. In this study we examine sperm morphology and motility in experimentally created hybrid long-tailed finches and compare them to ‘pure’ males of each subspecies. We found that hybrid males had longer midpiece than P. a. hecki males and significantly longer flagellum length than both subspecies, which we discuss in the context of the expected genetic composition of these groups. However, we found no evidence that ‘hybrid’ males had low sperm velocity or proportion of motile sperm in vitro, or for a relationship between sperm morphology and velocity. We discuss the opportunity posed by this system to investigate the genomic basis of reproductive traits that could propel this research field forward.Mode of access: World wide web1 online resource (55 pages) graphs, table
Investigating blood plasma levels of cytokines and amyloid-β as potential diagnostic biomarkers for preclinical Alzheimer’s disease
No full textEmpirical thesis.Bibliography: pages 51-61.Literature review -- Materials and methods -- Results -- Discussion -- Conclusions/future directions -- References -- Appendix.Alzheimer’s disease (AD) is the most common form of dementia, but to date there is no effective treatment. Therefore, preclinical diagnosis is necessary to prevent or improve therapeutic approaches for disease management. Mounting evidence shows that inflammatory processes involving various pro-inflammatory cytokines including interleukin (IL)-1β, IL-6 and tumour necrosis factor (TNF)-α contribute to AD pathogenesis. While inflammatory biomarkers have been extensively studied in clinically diagnosed AD subjects, there has been a paucity of information on inflammatory biomarkers in cognitively normal elderly subjects with a high neocortical amyloid-β load (NAL).Based on the findings of increased pro-inflammatory cytokines in clinical AD, I hypothesised that plasma levels of these cytokines are also increased in preclinical AD, and these increased cytokine levels may have diagnostic value, and functionally play a role in impairing cognition.In this study, approximately 100 plasma samples from healthy elderly adults with either high or low NAL were assessed for pro-inflammatory cytokines using conventional enzyme-linked immunosorbent assay (ELISA) kits. Furthermore, since plasma beta amyloid (Aβ) levels have recently been demonstrated to be altered in clinical AD, I investigated the levels of this peptide in preclinical AD. The Aβ results, which were expressed as the ratio of amyloid beta (Aβ) 40/42 were compared between low and high NAL subjects.The data collected were analysed using the statistical package for social sciences (SPSS). No significant differences in the plasma levels of all the pro-inflammatory cytokines were observed between the two groups, although there was a consistent trend of increased levels in the high NAL group. However, the ratio of Aβ 40/42 was significantly higher in the high NAL group compared to the low NAL, and receiver operating characteristic (ROC) curves were created to evaluate predictive models. The accuracy of prediction was increased when Aβ 40/42 was added to the base model.In conclusion, while the pro-inflammatory cytokines do not show promise as preclinical AD biomarkers based on the conventional ELISA assays used, the ratio of Aβ 40/42 is a potential candidate that merits inclusion in a diagnostic panel of biomarkers for preclinical diagnosis of AD.Mode of access: World wide web1 online resource (ix, 66 pages) colour illustration
Why was it that the Romans, during the last fifty years of the second century BC, departed from previous practice and began to establish a system of permanent courts (quaestiones perpetuae), rather than continuing with ad hoc proceedings?
No full textTheoretical thesis.Bibliography: pages 282-301.Chapter 1. Introduction -- Chapter 2. The Lex Calpurnia and the Quaestio de pecuniisrepetundis - 149 -- Chapter 3. Quaestio de sicariis et Quaestio de veneficiis - 67 -- Chapter 4. The Lex acilia of 123 and the Quastio de pecuniis repetundis -- Chapter 5. The Quaetio de ambitu -- Chapter 6. The Quaestio de peculatu -- Chapter 7. Lex appuleia de maiestate-103 -- Chapter 8. Sulla and the standing courts -- Chapter 9. Conclusion -- Bibliography.This thesis addresses the overarching question of why the Romans began to adopt from 149 the structure of permanent tribunals by reviewing, initially the judicial procedures to which the Senate had recourse in the previous quarter century. The Senate looked to these procedures with limited success in its efforts to stem the ruthless depredations visited on peregrini by its generals and provincial governors.The discussion is taken up in chapter one and provides an introduction as to the reasons for the creation in 149 of the first permanent court, the quaestio de pecuniis repetundis. In this chapter the hypothesis is advanced that the purpose of the creation of the court was more than just the desire to allow allies and friends of the Roman people a right of restitution. Rather it had a diplomatic rationale,namely to maintain existing foreign relationships and to provide the opportunity for forging new accords. The continual involvement of the Romans in foreign wars far from home with consequent stretched supply lines dictated the need for strategic alliances.In the succeeding chapters, three to seven, each court and its enabling statute is individually considered. It is argued that whilst with some courts other reasons may also have existed the primary reason can be found in the desire of the Senate as the foreign relations organ of Rome to pursue the diplomatic rationale. Thus, for example, the separate criminal courts, de sicariis and de veneficiis were established to deal with the unsettled conditions prevailing in Rome after the destruction of Carthage. However, the attempt thereby to restore a semblance of law and order is also to be seen as intended to encourage peregrini to ventilate their rights in a Rome in which their personal safety was not at risk.In chapter eight it is contended that Sulla clearly accepted the permanent system. He did not seek to change it nor to consolidate or reconstitute the permanent courts. Rather he adopted a piecemeal approach in “tacking” on to existing enabling laws measures which made moderated adjustments.Mode of access: World wide web1 online resource (viii, 301 pages
Foreign experience and corporate innovation in China
No full textEmpirical thesis.Bibliography: pages 36-40.1. Introduction -- 2. Related literature and hypothesis -- 3. Data and descriptive statistics -- 4. Empirical tests and results -- 5. Underlying mechanisms -- 6. Robustness checks -- 7. Conclusions -- References -- Appendix.In this thesis, we examine whether board of directors and senior executives with foreign experience affect a firm's innovation performance, which determines the firm's long term competitiveness, by utilising the data on foreign experience of directors and senior executives of all A-share listed companies in China from 1990 to 2010. We find that directors and senior executives with foreign experience increase innovative efficiency and result in more innovation output. It appears that the effect is more pronounced for senior-level overseas returnees who accumulated their foreign experience from countries with a higher standard of corporate governance, management practice and intellectual property rights protection, relative to their counterparts. Further, overseas returnees with commerce related degrees demonstrate a better performance in a firm's innovation output than overseas returnees with non-commerce related degrees. Our study documents that the foreign background of senior level returnees is able to increase the human capital of the firm that benefits the long-term firm's value adding by boosting the firm's innovation output.Mode of access: World wide web1 online resource (67 pages) table
Putting ‘Australians’ first: Australian news media construction of temporary migration and migrants
No full textTheoretical thesis.Bibliography: pages 85-96.Chapter 1. Introduction -- Chapter 2. Australian migration timeline -- Chapter 3. Migration, migrants and the news media -- Chapter 4. Theory, method and template -- Chapter 5. Australia's national interest -- Chapter 6. The 'victim' -- Chapter 7. The missing frame and the consequences for Australia -- Chapter 8. Discussion and conclusion -- References -- Appendix.This study focuses on Australian news media representations of temporary migration and migrants. It is driven by the question: what dominant discourses do contemporary news media produce of temporary migration and migrants? The question is answered by critically examining media discourse relating to the abolition of temporary work visa for migrants, popularly referred to as the ‘457 visa’. Fifteen online news articles from three Australian newspapers collected between 2017 and 2018 form the data for analysis.The study employs a multidisciplinary framework drawing from cultural studies, media studies and communication studies. It uses critical discourse analysis as its method and framing analysis as a tool to explore representations in dominant discourse to understand the construction of temporary migration and migrants by media.The analysis of media discourse on temporary migration reveals ideological representations. Within the dichotomy of ‘us’ and ‘them’ that govern media representations, temporary migrants form the ‘them’. This ideological position and binary nature is presented within the frame of ‘Australian national interest’. This leads to the perception of temporary migration and migrants as a threat to the nation and, consequently, a social problem that needs to be addressed. The abolition of the 457 visa is legitimised as the solution to the problem in news media discourse. The study argues that such representations have significant consequences for Australian society.Mode of access: World wide web1 online resource (98 pages) table