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Contribution Of Radicals And Ions In Catalyzed Growth Of Single-Walled Carbon Nanotubes From Low-Temperature Plasmas, Z Marvi, S Xu, G Foroutan, Kostya Ostrikov Jan 2015

Contribution Of Radicals And Ions In Catalyzed Growth Of Single-Walled Carbon Nanotubes From Low-Temperature Plasmas, Z Marvi, S Xu, G Foroutan, Kostya Ostrikov

Australian Institute for Innovative Materials - Papers

The growth kinetics of single-walled carbon nanotubes (SWCNTs) in a low-temperature, low-pressure reactive plasma is investigated using a multiscale numerical simulation, including the plasma sheath and surface diffusion modules. The plasma-related effects on the characteristics of SWCNT growth are studied. It is found that in the presence of reactive radicals in addition to energetic ions inside the plasma sheath area, the effective carbon flux, and the growth rate of SWCNT increase. It is shown that the concentration of atomic hydrogen and hydrocarbon radicals in the plasma plays an important role in the SWCNT growth. The effect of the effective carbon …


Functionalised Inherently Conducting Polymers As Low Biofouling Materials, Binbin Zhang, Alexander Nagle, Gordon G. Wallace, Timothy W. Hanks, Paul J. Molino Jan 2015

Functionalised Inherently Conducting Polymers As Low Biofouling Materials, Binbin Zhang, Alexander Nagle, Gordon G. Wallace, Timothy W. Hanks, Paul J. Molino

Australian Institute for Innovative Materials - Papers

Diatoms are a major component of microbial biofouling layers that develop on man-made surfaces placed in aquatic environments, resulting in significant economic and environmental impacts. This paper describes surface functionalisation of the inherently conducting polymers (ICPs) polypyrrole (PPy) and polyaniline (PANI) with poly(ethylene glycol) (PEG) and their efficacy as fouling resistant materials. Their ability to resist interactions with the model protein bovine serum albumin (BSA) was tested using a quartz crystal microbalance with dissipation monitoring (QCM-D). The capacity of the ICP-PEG materials to prevent settlement and colonisation of the fouling diatom Amphora coffeaeformis (Cleve) was also assayed. Variations were demonstrated …


Superior Critical Current Density Obtained In Mg11b2 Low Activation Superconductor By Using Reactive Amorphous 11b And Optimizing Sintering Temperature, Fang Cheng, Yongchang Liu, Zongqing Ma, Huijun Li, Md Shahriar Hossain Jan 2015

Superior Critical Current Density Obtained In Mg11b2 Low Activation Superconductor By Using Reactive Amorphous 11b And Optimizing Sintering Temperature, Fang Cheng, Yongchang Liu, Zongqing Ma, Huijun Li, Md Shahriar Hossain

Australian Institute for Innovative Materials - Papers

The un-doped Mg11B2 and Cu-doped Mg11B2 bulks using 11B as a boron precursor were fabricated by solid-state reaction and sintered at different temperature in present work. By analyzing the sintering process, it was found that 11B original powder is more reactive and can react with Mg severely even at low temperature before Mg melting, which leads to the formation of refined Mg11B2 grains. Consequently, the critical current density of Mg11B2 sample prepared in this work is higher than that of natural MgB2. Furthermore, it was found that proper Cu addition …


Improving Low Voltage Ride-Through Using Super Capacitor At The Dc Link Of Doubly-Fed Induction Generator Based Wind Turbine, Ahmed M. Haidar, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi Jan 2015

Improving Low Voltage Ride-Through Using Super Capacitor At The Dc Link Of Doubly-Fed Induction Generator Based Wind Turbine, Ahmed M. Haidar, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a simple methodology to improve the low voltage ride-through (LVRT) capability of Doubly Fed Induction Generator (DFIG) based wind turbines in order to ride through higher voltage sags and durations. The proposed method is based on selection of an appropriate value for DC side super capacitor (SC) in such a way that it could help wind turbine for LVRT without any need to crowbar protection. The operation of SC based wind turbine in normal and fault conditions is simulated using MATLAB/SIMULINK. The simulation results show that the proposed method can be used effectively for LVRT improvement and …


Characteristics Of Power Quality Disturbances In Australia: Voltage Dips At Low-Voltage Sites, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, Sarath Perera, Philip Ciufo, Gerrard M. Drury Jan 2015

Characteristics Of Power Quality Disturbances In Australia: Voltage Dips At Low-Voltage Sites, Sean T. Elphick, Victor W. Smith, Victor J. Gosbell, Sarath Perera, Philip Ciufo, Gerrard M. Drury

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage dips are considered to be one of the costliest of all power quality disturbances due to their disruption of industrial and commercial operations. The ability to characterise the voltage dip performance of distribution networks has many benefits for industry. There is considerable potential for industry to make large economic gains if voltage dip behaviour can be better understood and planned for. To put strategies in place to deal with voltage dips, there is a need for extensive data collection and analysis so that correct planning decisions can be made. This study details the characteristics of voltage dip data which …


Voltage Sag Compensation Of Point Of Common Coupling For Low Voltage Ride-Through Enhancment Of Inverter Interfaced Dg Using Bridge Type Fcl, Seyed Behzad Naderi, Michael Negnevitsky, Amin Jalilian, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi Jan 2015

Voltage Sag Compensation Of Point Of Common Coupling For Low Voltage Ride-Through Enhancment Of Inverter Interfaced Dg Using Bridge Type Fcl, Seyed Behzad Naderi, Michael Negnevitsky, Amin Jalilian, Mehrdad Tarafdar Hagh, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

Fully converter wind turbines and solar power utilise an inverter to connect to grid. The inverters are vulnerable to voltage sag in their terminal due to its damaging effect on semiconductor self-Turnoff switches. In this paper, a bridge-Type fault current limiter (B-FCL) is proposed for low voltage ride-Through (LVRT) of the inverters during different types of fault with simple control system. The proposed B-FCL is capable to compensate the voltage sag in point of common coupling (PCC) and makes a safe condition not only for the inverter but also for any equipment which has been connected to the PCC in …


Interface Analysis And Hot Deformation Behaviour Of A Novel Laminated Composite With High-Cr Cast Iron And Low Carbon Steel Prepared By Hot Compression Bonding, Zhengyi Jiang, Xingjian Gao, Sheng-Li Li, Hong Mei Zhang, Dengfu Chen, Jian Zhong Xu Jan 2015

Interface Analysis And Hot Deformation Behaviour Of A Novel Laminated Composite With High-Cr Cast Iron And Low Carbon Steel Prepared By Hot Compression Bonding, Zhengyi Jiang, Xingjian Gao, Sheng-Li Li, Hong Mei Zhang, Dengfu Chen, Jian Zhong Xu

Faculty of Engineering and Information Sciences - Papers: Part A

A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron (HCCI) as the inner layer and low carbon steel (LCS) as the outer layers on a Gleeble 3500 thermomechanical simulator at a temperature of 950 °C and a strain rate of 0.001 S-1. Interfacial bond quality and hot deformation behaviour of the laminate were studied by microstructural characterisation and mechanical tests. Experimental results show that the metallurgical bond between the constituent metals was achieved under the proposed bonding conditions without discernible defects and the formation of interlayer or intermetallic layer …


Application Of The Largest Lyapunov Exponent Algorithm For Feature Extraction In Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Prabuono Buyung Kosasih, A Kiet Tieu, Craig A. S Moodie Jan 2015

Application Of The Largest Lyapunov Exponent Algorithm For Feature Extraction In Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Prabuono Buyung Kosasih, A Kiet Tieu, Craig A. S Moodie

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a new application of the largest Lyapunov exponent (LLE) algorithm for feature extraction method in low speed slew bearing condition monitoring. The LLE algorithm is employed to measure the degree of non-linearity of the vibration signal which is not easily monitored by existing methods. The method is able to detect changes in the condition of the bearing and demonstrates better tracking of the progressive deterioration of the bearing during the 139 measurement days than comparable methods such as the time domain feature methods based on root mean square (RMS), skewness and kurtosis extraction from the raw vibration …


Comparative Evaluation Of Modern Dosimetry Techniques Near Low- And High-Density Heterogeneities, Eyad A. Alhakeem, Sami Alshaikh, Anatoly B. Rosenfeld, Sergei F. Zavgorodni Jan 2015

Comparative Evaluation Of Modern Dosimetry Techniques Near Low- And High-Density Heterogeneities, Eyad A. Alhakeem, Sami Alshaikh, Anatoly B. Rosenfeld, Sergei F. Zavgorodni

Faculty of Engineering and Information Sciences - Papers: Part A

The purpose of this study is to compare performance of several dosimetric methods in heterogeneous phantoms irradiated by 6 and 18 MV beams. Monte Carlo (MC) calculations were used, along with two versions of Acuros XB, anisotropic analytical algorithm (AAA), EBT2 film, and MOSkin dosimeters. Percent depth doses (PDD) were calculated and measured in three heterogeneous phantoms. The first two phantoms were a 30 x 30 x 30 cm3 solid-water slab that had an air-gap of 20x 2.5 x 2.35 cm3. The third phantom consisted of 30 x 30 x 5 cm3 solid water slabs, two 30 x 30 x …


Effect Of Pre-Quenching Process On Microstructure And Mechanical Properties In A Nb-Microalloyed Low Carbon Q-P Steel, Jun Zhang, Hua Ding, Jingwei Zhao Jan 2015

Effect Of Pre-Quenching Process On Microstructure And Mechanical Properties In A Nb-Microalloyed Low Carbon Q-P Steel, Jun Zhang, Hua Ding, Jingwei Zhao

Faculty of Engineering and Information Sciences - Papers: Part A

A refined microstructure consisting of martensite and retained austenite at room temperature has been produced in a Nb-microalloyed low carbon Si-Mn steel by a novel heat-treatment, pre-quenching prior to quenching and partitioning processes (Q&Q-P). The results showed that compared with the conventional quenching and partitioning steel the mechanical properties of steel obtained by the novel treatment have been significantly improved, with a good combination of ultimate tensile strength (1000MPa) and total elongation (above 30%). Meanwhile, the volume fraction of retained austenite has been increased. It was found that the improvement of mechanical properties was mainly attributed to the enhanced TRIP …


High Rate Serially Concatenated Codes With Low Error Floors, Bo Liu, Sheng Tong, Qinghua Guo, Jun Tong, Jiangtao Xi, Yanguang Yu Jan 2015

High Rate Serially Concatenated Codes With Low Error Floors, Bo Liu, Sheng Tong, Qinghua Guo, Jun Tong, Jiangtao Xi, Yanguang Yu

Faculty of Engineering and Information Sciences - Papers: Part A

Serial concatenation of Hamming codes and an accumulator has been shown to achieve near capacity performance at high code rates. However, these codes usually exhibit poor error floor performance due to their small minimum distances. To overcome this weakness, we propose to replace the outer Hamming codes by product codes constructed from Hamming codes and single-parity-check codes. In this way, the minimum distance of the outer code can be doubled, which is expected to increase the minimum distance of the serially concatenated code and thus to improve error floor performance. Three-dimensional EXIT chart is used for their convergence analysis and …


An Application Of Mathematical Morphology Operators As Features Extraction Method For Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Dwi B. Wibowo, Mochammad Ariyanto, Joga D. Setiawan Jan 2015

An Application Of Mathematical Morphology Operators As Features Extraction Method For Low Speed Slew Bearing Condition Monitoring, Wahyu Caesarendra, Dwi B. Wibowo, Mochammad Ariyanto, Joga D. Setiawan

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a new application of mathematical morphology (MM) operators for low speed slew bearing condition monitoring. The MM operators were used as a signal processing step and feature extraction method for bearing vibration signals. Four basic MM operators; erosion, dilation, closing and opening, were studied. This paper also investigates another potential MM operator, namely gradient operator. Two common time domain features in bearing condition monitoring, namely root mean square (RMS) and kurtosis, were extracted from the processed signal. The study shows that the changes in bearing condition can be clearly detected from the extracted features (RMS and kurtosis) …


Analysis Of Low-Field Isotropic Vortex Glass Containing Vortex Groups In Yba2cu3o7−X Thin Films Visualized By Scanning Squid Microscopy, Frederick Wells, Alexey V. Pan, Renshaw Wang, Sergey Fedoseev, Hans Hilgenkamp Jan 2015

Analysis Of Low-Field Isotropic Vortex Glass Containing Vortex Groups In Yba2cu3o7−X Thin Films Visualized By Scanning Squid Microscopy, Frederick Wells, Alexey V. Pan, Renshaw Wang, Sergey Fedoseev, Hans Hilgenkamp

Australian Institute for Innovative Materials - Papers

The glass-like vortex distribution in pulsed laser deposited YBa2Cu3O7 − x thin films is observed by scanning superconducting quantum interference device microscopy and analysed for ordering after cooling in magnetic fields significantly smaller than the Earth's field. Autocorrelation calculations on this distribution show a weak short-range positional order, while Delaunay triangulation shows a near-complete lack of orientational order. The distribution of these vortices is finally characterised as an isotropic vortex glass. Abnormally closely spaced groups of vortices, which are statistically unlikely to occur, are observed above a threshold magnetic field. The origin of these groups …


Significantly Enhanced Critical Current Density In Nano-Mgb2 Grains Rapidly Formed At Low Temperature With Homogeneous Carbon Doping, Yongchang Liu, Feng Lan, Zongqing Ma, Ning Chen, Huijun Li, Shaon Barua, Dipakkumar Patel, Md S. Hossain, S Acar, Jung Ho Kim, S X. Dou Jan 2015

Significantly Enhanced Critical Current Density In Nano-Mgb2 Grains Rapidly Formed At Low Temperature With Homogeneous Carbon Doping, Yongchang Liu, Feng Lan, Zongqing Ma, Ning Chen, Huijun Li, Shaon Barua, Dipakkumar Patel, Md S. Hossain, S Acar, Jung Ho Kim, S X. Dou

Australian Institute for Innovative Materials - Papers

High performance MgB2 bulks using carbon-coated amorphous boron as a boron precursor were fabricated by Cu-activated sintering at low temperature (600 °C, below the Mg melting point). Dense nano-MgB2 grains with a high level of homogeneous carbon doping were formed in these MgB2 samples. This type of microstructure can provide a stronger flux pinning force, together with depressed volatility and oxidation of Mg owing to the low-temperature Cu-activated sintering, leading to a significant improvement of critical current density (Jc) in the as-prepared samples. In particular, the value of Jc for the carbon-coated (Mg …