A theoretical and empirical investigation into the growth of ultralong carbon nanotubes

Carbon nanotubes (CNTs) were first discovered and named as such by Iijima in 1991. Various institutes and researchers have since widely conducted ongoing research on carbon nanotube growth. The exceptional properties of CNTs, including their electrical and mechanical properties, aim to revolutionise the applications of electronics and devices in the future such as transmission power lines and lightweight high-strength carbon nanotube fibres. Therefore, understanding the mechanisms of growing ultra-long carbon nanotubes (UL-CNTs) that can increase the length to more than a centimetre long can unlock the full potential of the CNTs. This PhD project will have three parts: (Ⅰ) the growth experiments using different types of monometallic & bimetallic iron based catalysts for growing carbon nanotubes; (Ⅱ) the computational simulation of flow fields around carbon nanotube geometry in a micro-scale; (Ⅲ) the applications of carbon nanotubes produced from waste plastics, such as Ethernet & audio cables, and public engagement events about the research. In the growth experiment topic, the primary objective of this research is to study the catalyst activities on the rate of carbon nanotube growth using monometallic (Fe) & bimetallic catalysts (Fe-Cu, Fe-Co, Fe-Ni, Fe-Sn, Fe-Ga, Fe-Mg & Fe-Al) dissolved in deionised water, and find which catalysts have the potential to grow the longest carbon nanotubes with improved characteristics, such as G/D (graphene/ disorders) ratio. As we know, the carbon source gas flow rate and reactor temperature profiles can affect the length of carbon nanotubes from the literature; an effective way to optimise experimental conditions to grow UL-CNTs is to use computational fluid dynamics (CFD) modelling methods. So far, there has been little research on the growth of ultra-long carbon nanotubes under a non-continuous flow environment on a nanoscale. Most computational modelling studies have only focused on the continuity of flow in a traditional approach. This research uses the BGK-Boltzmann equation and molecular collision models to investigate flow behaviours at the nanoscopic scale. Thus, this study provides an exciting opportunity to advance the knowledge of growing ultra-long carbon nanotubes (UL-CNTs) of centimetre length or higher and may be used in applications including the carbon nanotube Ethernet and audio cables as mentioned in this project

The modelling of accident frequency using risk exposure data for the assessment of airport safety areas

This thesis makes significant contributions to improving the use of Airport Safety Areas (ASAs) as aviation accident risk mitigation measures by developing improved accident frequency models and risk assessment methodologies. In recent years, the adequacy of ASAs such as the Runway End Safety Area and Runway Safety Area has come under increasing scrutiny. The current research found flaws in the existing ASA regulations and airport risk assessment techniques that lead to the provision of inconsistent safety margins at airports and runways. The research was based on a comprehensive database of ASA-related accidents, which was matched by a representative sample of normal operations data, such that the exposure to a range of operational and meteorological risk factors between accident and normal flights could be compared. On this basis, the criticality of individual risk factors was quantified and accident frequency models were developed using logistic regression. These models have considerably better predictive power compared to models used by previous airport risk assessments. An improved risk assessment technique was developed coupling the accident frequency models with accident location data, yielding distributions that describe the frequency of accidents that reach specific distances beyond the runway end or centreline given the risk exposure profile of the particular runway. The application of the proposed methodology was demonstrated in two case studies. Specific recommendations on ASA dimensions were made for achieving consistent levels of safety on each side of the runway. Advances made in this study have implications on the overall assessment and management of risks at airports

Synthesis and experimental validation of a new probabilistic strategy to minimize heat transfers used in conditioning of dry air in buildings with fluctuating ambient and room occupancy

Steady-state unit-operations are globally used in chemical engineering. Advantages include ease of control and a uniform product quality. Nonetheless there will be naturally occurring, random (stochastic) fluctuations about any steady-state ‘set’ value of a process parameter. Traditional chemical engineering does not explicitly take account of these. This is because, generally, fluctuation in one parameter appears to be off-set by change in another – with the process outcome remaining apparently steady. However Davey and co-workers (e.g. Davey et al., 2015; Davey, 2015 a; Zou and Davey, 2016; Abdul-Halim and Davey, 2016; Chandrakash and Davey, 2017 a) have shown these naturally occurring fluctuations can accumulate and combine unexpectedly to leverage significant impact and thereby make apparently well-running processes vulnerable to sudden and surprise failure. They developed a probabilistic and quantitative risk framework they titled Fr 13 (Friday 13th) to underscore the nature of these events. Significantly, the framework can be used in ‘second-tier’ studies for re-design to reduce vulnerability to failure. Here, this framework is applied for the first time to show how naturally occurring fluctuations in peak ambient temperature (T₀) and occupancy (room traffic flows) (Lᴛ) can impact heat transfers for conditioning of room air. The conditioning of air in large buildings, including hotels and hospitals, is globally important (Anon., 2012 a). The overarching aim is to quantitatively ‘use’ these fluctuations to develop a strategy for minimum energy. A justification is that methods that permit quantitative determination of reliable strategies for conditioning of air can lead to better energy use, with potential savings, together with reductions in greenhouse gases (GHG). Oddly many buildings do not appear to have a quantitative strategy to minimize conditioning heat transfers. Wide-spread default practice is to simply use an on-off strategy i.e. conditioning-on when the room is occupied and conditioning-off, when un-occupied. One alternative is an on-only strategy i.e. leave the conditioner run continuously. A logical and stepwise combined theoretical-and-experimental, approach was used as a research strategy. A search of the literature showed that work had generally focused on discrete, deterministic aspects and not on mathematically rigorous developments to minimise overall whole-of-building conditioning heat transfers. A preliminary steady-state convective model was therefore synthesized for conditioning air in a (hotel) room (4.5 x 5.0 x 2.5, m) in dry, S-E Australia during summer (20 ≤ T₀ ≤ 40, °C) to an auto-set room bulk temperature of 22 °C for the first time. This was solved using traditional, deterministic methods to show the alternative on-only strategy would use less electrical energy than that of the default on-off for Lᴛ > 36 % (Chu et al., 2016). Findings underscored the importance of the thermal capacitance of a building. The model was again solved using the probabilistic Fr 13 framework in which distributions to mimic fluctuations in T₀ and Lᴛ were (reasonably) assumed and a new energy risk factor (p) was synthesized such that all p > 0 characterized a failure in applied energy strategy (Chu and Davey, 2015). Predictions showed on-only would use less energy on 86.6 % of summer days. Practically, this meant that a continuous on-only strategy would be expected to fail in only 12 of the 90 days of summer, averaged over the long term. It was concluded the Fr 13 framework was an advance over the traditional, deterministic method because all conditioning scenarios that can practically exist are simulated. It was acknowledged however that: 1) a more realistic model was needed to account for radiative heat transfers, and; 2) to improve predictive accuracy, local distributions for T₀ and Lᴛ were needed. To address these: 1) the model was extended mathematically to account for radiative transfers from ambient to the room-interior, and; 2) distributions were carefully-defined based on extensive historical data for S-E Australia from, respectively, Bureau of Meteorology (BoM) (Essendon Airport) and Clarion Suites Gateway Hotel (CSGH) (Melbourne) – a large (85 x 2-room suites) commercial hotel (latitude -37.819708, longitude 144.959936) – for T₀ and Lᴛ for 541 summer days (Dec. 2009 to Feb. 2015) (Chu and Davey, 2017 a). Predictions showed that radiative heat transfers were significant and highlighted that for Lᴛ ≥ 70 %, that is, all commercially viable occupancies, the on-only conditioning strategy would be expected to use less energy. Because findings predicted meaningful savings with the on-only strategy, ‘proof-of-concept’ experiments were carried out for the first time in a controlled-trial in-situ in CSGH over 10 (2 x 5 contiguous) days of summer with 24.2 ≤ T₀ ≤ 40.5, °C and 13.3 ≤ Lᴛ ≤ 100, %. Independent invoices (Origin Energy Ltd, or Simply Energy Ltd, Australia) (at 30 min intervals from nationally registered ‘smart’ power meters) for geometrically identical control and treated suites showed a mean saving of 18.9 % (AUD $2.23 per suite per day) with the on-only strategy, with a concomitant 20.7 It was concluded that because findings supported model predictions, and because robust experimental SOPs had been established and agreed by CSGH, a large-scale validation test of energy strategies should be undertaken in the hotel. Commercial-scale testing over 77 contiguous days of summer (Jan. to Mar., 2016) was carried out in two, dimensionally-identical 2-room suites, with the same fit-out and (S-E) aspect, together with identical air-conditioner (8.1 kW) and nationally registered meters to automatically transmit contiguous (24-7) electrical use (at 30 min intervals) (n = 3,696) for the first time. Each suite (10.164 x 9.675, m floor plan) was auto-set to a bulk air temperature of 22 °C (Chu and Davey, 2017 b). In the treated suite the air-conditioner was operated on-only, whilst in the control it was left to wide-spread industry practice of on-off. The suites had (standard) single-glazed pane windows with heat-attenuating (fabric) internal curtains. Peak ambient ranged from 17.8 ≤ T₀ ≤ 39.1, °C. There were 32 days with recorded rainfall. The overall occupancy Lᴛ of both suites was almost identical at 69.7 and 71.2, An actual reduction in electrical energy costs of AUD$0.75 per day (9 %) averaged over the period was demonstrated for the treated suite. It was concluded therefore that experimental findings directly confirmed the strategy hypothesis that continuous on-only conditioning will use less energy. Although the hypothesis appeared generalizable, and adaptable to a range of room geometries, it was acknowledged that a drawback was that extrapolation of results could not be reliably done because actual energy used would be impacted by seasons. The in-situ commercial-scale experimental study was therefore extended to encompass four consecutive seasons. The research aim was to provide sufficient experimental evidence (n = 13,008) to reliably test the generalizability of the on-only hypothesis (Chu and Davey, 2017 c). Ambient peak ranged from 9.8 ≤ T₀ ≤ 40.5, °C, with rainfall on 169 days (62 %). Overall, Lᴛ was almost identical at 71.9 and 71.7, % respectively, for the treated and control suite. Results based on independent electrical energy invoices showed the on-only strategy used less energy on 147 days (54 %) than the on-off. An overall mean energy saving of 2.68 kWh per suite per day (9.2 %) (i.e. AUD $0.58 or 8.0$18,006 per annum - plus credit certificates that could be used to increase savings. Overall, it was concluded therefore the on-only conditioning hypothesis is generalizable to all seasons, and that there appears no barrier to adaption to a range of room geometries. Highly significantly, the methodology could be readily applied to existing buildings without capital outlays or increases in maintenance. A total of five (5) summative research presentations of results and findings were made to the General Manager and support staff of CSGH over the period to July 2017 inclusive (see Appendix I) that maintained active industry-engagement for the study. To apply these new findings, the synthesis of a computational algorithm in the form of a novel App (Anon., 2012 b; Davey, 2015 b) was carried out for the first time (Chu and Davey, 2017 d). The aim was to demonstrate an App that could be used practically to minimize energy in conditioning of dry air in buildings that must maintain an auto-set temperature despite the impact of fluctuations in T₀ and Lᴛ . The App was synthesized from the extensive experimental commercial-scale data and was applied to compute energy for both strategies from independently forecast T₀ and Lᴛ . Practical performance of the App was shown to be dependent on the accuracy of locally forecast T₀ and Lᴛ . Overall results predicted a saving of 2.62 kWh per 2-room suite per day ($47,870 per annum for CSGH) where accuracy of forecast T₀ is 77 % and Lᴛ is 99 %, averaged over the long term. A concomitant benefit was a predicted reduction greenhouse emissions of 3.1 kg CO₂-e per day. The App appears generalizable – and importantly it is not limited by any underlying heat-model. Its predictive accuracy can be refined with accumulation of experimental data for a range of geo-locations and building-types to make it globally applicable. It was concluded that the App is a useful new tool to minimize energy transfers in conditioning of room dry air in large buildings – and could be readily developed commercially 6. Importantly, it can be applied without capital outlays or additional maintenance cost and at both design and analysis stages. This research is original and not incremental work. Results of this research will be of immediate benefit to risk analysts, heat-design engineers, and owners and operators of large buildings.Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering, 201

The fabrication and application of carbon nanotube-based hybrid nanomaterials

The evolution of technology has reached a stage where the performances and dimension needed are outpacing what conventional materials can deliver. This has been made more acute with the further necessity of miniaturisation. Therefore, new materials which can overcome this bottleneck are required. Over the past few decades, it was found that when a material is reduced to the nanoscale, they can exhibit properties unparallel by their bulk counterparts. Therefore these nanomaterials poise as a promising candidate for future applications. Of the many nanomaterials, carbon nanotube (CNT) is among the most emblematic. CNT is a hollow one-dimensional structure comprising solely of carbon atoms. They are fascinating as they exhibit physical attributes which surpass many conventional materials and their nanoscale dimension allows greater flexibility in their deployments. However, the utilisation of CNTs is currently frustrated by a host of intrinsic and extrinsic factors. As a result, there are usually significant disparity between their predicted capability and real-world performance. Therefore, the practical application of CNTs remains unfeasible. The premise of this thesis is that by employing CNTs in conjunction with other materials, the hurdles which plague their utilisation may be overcome. Here, the concept of CNT-based hybrid nanomaterials is presented. This thesis demonstrates that by engineering complementary interaction between two materials, many challenges which hamper the utilisations of CNTs and other nanomaterials can indeed be negated. Furthermore, their synergistic interaction allows the performance of the CNT-based hybrid nanomaterials to be superior to their uncoupled precursors. Therefore, this could be a viable strategy to incorporating nanomaterials in a range of applications

An Exegetical Translation of a Section of the Vimalakirti-Nirdesa Sutra Together with the Commentary of SENG-CH\u27ÄO

The following pages comprise a translation of a section of the 維摩詰經 (VimalakIrti-nirdesa satra; Taisho Issaikyo, 475; Nanjio, 146), together with the joint commentary of Seng Chao () and Kumarjiva, to which a number of interpretative and exegetical notes have been added. The texts used have been those published in the Pu- haush To \u27ung Shu edition. This is the version translated by KumarjIva from the Sanskrit, probably somewhere between A.D. 401 and 413. The commentator Seng Ch\u27ao was his con- temporary and student, dying a year later than his teacher in 414

Immunopathological Effects Of Aquaporin-4 Ig G In Neuromyelitis Optica Spectrum Disorders

published_or_final_versio

An Annotated Translation of the WU LIANG I CHING (The Sutra of the Immeasurable meaning)

The following pages comprise a translation of the whose sanskrit title was presumably the apramanartha sutra from the \u27Yuan\u27 Edition of 1290 A.D., together with an introduction by liu Ch\u27iu . It was first translated from the sanskrit into Chinese by Dharmagstayadas, a Buddhist monk from North Central India, with the help of Hui Piao, In 485 A.D. La the Wu Tang mountains. The Sanskrit version is not avallable, while there are known to be four Chinese editions of the sutra. They are the (Kao-Ll RAtston 1115 A.D.), 2舊宋本 (the Old Sung Idition 1104-1148 A.D.), (the Yuan Edition 1290 A.D.), and the Ming Idition 1601 A,D.). Although the pre- sent translation was based on the Yuas text, with which the translators have been faniliar for many years, 1t has been compared throughout with the Kao-Ii Idition (Taisbo 276), and an appendix of the variations is added at the end

Diagnostic accuracy of nonword repetition and sentence repetition in Cantonese-speaking children with specific language impairment (SLI)

Includes bibliographical references (p. 29-31)."A dissertation submitted in partial fulfillment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2010."Thesis (B.Sc)--University of Hong Kong, 2010.The study investigated the diagnostic accuracy of nonword repetition (NWR) and sentence repetition (SR) tasks in Cantonese-speaking children with Specific Language Impairment (SLI). Thirteen children with language impairment (LI) and 17 of their typically developing (TD) peers were recruited from local kindergartens with integrated programs. The SLI group was a subsample of the LI group, which contained 9 children. All the children were compared on NWR and SR tasks. The use of i) clinical status, ii) the children’s Hong Kong Cantonese Grammar (HKCG) subtest scores as the grouping variable was explored. The TD group scored significantly higher than the SLI group on NWR and SR when (ii) was used as the grouping variable. In terms of diagnostic accuracy, both NWR and SR failed to achieve a value of above 80% for both sensitivity and specificity. Theoretical and clinical implications of the results obtained are discussed.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science