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University of Wollongong

Faculty of Engineering - Papers (Archive)

Carbon

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Full-Text Articles in Engineering

Effect Of Ply Configuration On Hollow Square Reinforced Concrete Columns Confined With Carbon Fibre-Reinforced Polymer (Cfrp), T D. Le, M T. Lester, Muhammad N. S Hadi Jan 2013

Effect Of Ply Configuration On Hollow Square Reinforced Concrete Columns Confined With Carbon Fibre-Reinforced Polymer (Cfrp), T D. Le, M T. Lester, Muhammad N. S Hadi

Faculty of Engineering - Papers (Archive)

This paper presents results of testing twelve hollow square reinforced concrete specimens wrapped with Carbon fibre reinforced polymer CFRP. The effect of ply configuration on the behaviour of the specimens is investigated. All specimens were 800mm high and had the dimensions of 200mm×200mm in cross-section and a hollow core of 80mm×80 mm. The specimens were divided into four groups with three specimens each. The specimens in the first group without bonding CFRP served as references. While the remaining three groups of specimens were externally wrapped with CFRP in three different ply configurations of hoop, vertical and 45◦ angle with reference …


Removal Of Trace Organic Contaminants By A Membrane Bioreactor-Granular Activated Carbon (Mbr -Gac) System, Luong N. Nguyen, Faisal I. Hai, Jinguo Kang, William E. Price, Long Nghiem Jan 2012

Removal Of Trace Organic Contaminants By A Membrane Bioreactor-Granular Activated Carbon (Mbr -Gac) System, Luong N. Nguyen, Faisal I. Hai, Jinguo Kang, William E. Price, Long Nghiem

Faculty of Engineering - Papers (Archive)

The removal of trace organics by a membrane bioreactor–granular activated carbon (MBR–GAC) integrated system were investigated. The results confirmed that MBR treatment can be effective for the removal of hydrophobic (logD > 3.2) and readily biodegradable trace organics. The data also highlighted the limitation of MBR in removing hydrophilic and persistent compounds (e.g. carbamazepine, diclofenac, and fenoprop) and that GAC could complement MBR very well as a post-treatment process. The MBR– GAC system showed high removal of all selected trace organics including those that are hydrophilic and persistent to biological degradation at up to 406 bed volumes (BV). However, over an …


A "Skeleton/Skin"Strategy For Preparing Ultrathin Free-Standing Single-Walled Carbon Nanotube/Polyaniline Films For High Performance Supercapacitor Electrodes, Zhiqiang Niu, Pingshan Luan, Qi Shao, Haibo Dong, Jinzhu Li, Jun Chen, Duan Zhao, Le Cai, Weiya Zhou, Xiaodong Chen, Sishen Xie Jan 2012

A "Skeleton/Skin"Strategy For Preparing Ultrathin Free-Standing Single-Walled Carbon Nanotube/Polyaniline Films For High Performance Supercapacitor Electrodes, Zhiqiang Niu, Pingshan Luan, Qi Shao, Haibo Dong, Jinzhu Li, Jun Chen, Duan Zhao, Le Cai, Weiya Zhou, Xiaodong Chen, Sishen Xie

Faculty of Engineering - Papers (Archive)

One of the most critical aspects in the preparation of single-walled carbon nanotubes (SWCNTs)/ conducting polymer hybrid electrodes is to improve the energy density without seriously deteriorating their high power capability. Here, we report a ‘‘skeleton/skin’’ strategy for the preparation of freestanding, thin and flexible SWCNT/polyaniline (PANI) hybrid films by a simple in situ electrochemical polymerization method using directly grown SWCNT films with a continuous reticulate structure as template. In situ electrochemical polymerization can achieve effective deposition of PANI onto the surface of SWCNT bundles in the films and control the morphology and microstructure of the SWCNT/PANI hybrid films. In …


Carbon Nanotube Nanoweb-Bioelectrode For Highly Selective Dopamine Sensing, Jie Zhao, Weimin Zhang, Peter Sherrell, Joselito M. Razal, Xu-Feng Huang, Andrew I. Minett, Jun Chen Jan 2012

Carbon Nanotube Nanoweb-Bioelectrode For Highly Selective Dopamine Sensing, Jie Zhao, Weimin Zhang, Peter Sherrell, Joselito M. Razal, Xu-Feng Huang, Andrew I. Minett, Jun Chen

Faculty of Engineering - Papers (Archive)

A highly sensitive and selective dopamine sensor was fabricated with the unique 3D carbon nanotube nanoweb (CNT-N) electrode. The as-synthesised CNT-N was modified by oxygen plasma to graft functional groups in order to increase selective electroactive sites at the CNT sidewalls. This electrode was characterized physically and electrochemically using HRSEM, Raman, FT-IR, and cyclic voltammetry (CV). Our investigations indicated that the O2-plasma treated CNT-N electrode could serve as a highly sensitive biosensor for the selective sensing of dopamine (DA, 1 μM to 20 μM) in the presence of ascorbic acid (AA, 1000 μM).


Carbon Nanotube/Graphene Nanocomposite As Efficient Counter Electrodes In Dye-Sensitized Solar Cells, Josef Velten, Attila J. Mozer, Dan Li, David Officer, G G. Wallace, Ray Baughman, A Zakhidov Jan 2012

Carbon Nanotube/Graphene Nanocomposite As Efficient Counter Electrodes In Dye-Sensitized Solar Cells, Josef Velten, Attila J. Mozer, Dan Li, David Officer, G G. Wallace, Ray Baughman, A Zakhidov

Faculty of Engineering - Papers (Archive)

We demonstrated the replacement of the Pt catalyst normally used in the counter electrode of a dye-sensitized solar cell (DSSC) by a nanocomposite of dry spun carbon multi-walled nanotube (MWNT) sheets with graphene flakes (Gr-F). The effectiveness of this counter electrode on the reduction of the triiodide in the iodide/triiodide redox (I−/I− 3 ) redox reaction was studied in parallel with the use of the dry spun carbon MWNT sheets alone and graphene flakes used independent of each other. This nanocomposite deposited onto fluorinated tin-oxide-coated glass showed improved catalytic behavior and power conversion efficiency (7.55%) beyond the use of the …


Biomorphic Porous Graphitic Carbon For Electromagnetic Interference Shielding, Qinglei Liu, Jiajun Gu, Wang Zhang, Yoshinari Miyamoto, Zhixin Chen, Di Zhang Jan 2012

Biomorphic Porous Graphitic Carbon For Electromagnetic Interference Shielding, Qinglei Liu, Jiajun Gu, Wang Zhang, Yoshinari Miyamoto, Zhixin Chen, Di Zhang

Faculty of Engineering - Papers (Archive)

Using a kind of plant biomass (coconut shell) as template and carbon precursor, we prepare biomorphic porous carbon materials for electromagnetic interference shielding application. The carbon frameworks of the porous carbon materials are modified by in situ formation of graphitic nanostructures in a catalytic graphitization process, leading to well-tailored electrical conductivity of the resultant materials. The modified porous carbon materials exhibit shielding effectiveness of 40 dB over the X-band frequency, and the shielding by absorption is as high as 91%, indicating an absorptiondominant shielding mechanism. The high absorption contribution is attributed to the coupled effects of the biomorphic porous structures …


Synthesis Of Uniform Tio2@Carbon Composite Nanofibers As Anode For Lithium Ion Batteries With Enhanced Electrochemical Performance, Zunxian Yang, Guodong Du, Qing Meng, Zaiping Guo, Xuebin Yu, Zhixin Chen, Tailiang Guo, Rong Zeng Jan 2012

Synthesis Of Uniform Tio2@Carbon Composite Nanofibers As Anode For Lithium Ion Batteries With Enhanced Electrochemical Performance, Zunxian Yang, Guodong Du, Qing Meng, Zaiping Guo, Xuebin Yu, Zhixin Chen, Tailiang Guo, Rong Zeng

Faculty of Engineering - Papers (Archive)

Very large area, uniform TiO2@carbon composite nanofibers were easily prepared by thermal pyrolysis and oxidization of electrospun titanium(IV) isopropoxide/polyacrylonitrile (PAN) nanofibers in argon. The composite nanostructures exhibit the unique feature of having TiO2 nanocrystals encapsulated inside a porous carbon matrix. The unique orderly-bonded nanostructure, porous characteristics, and highly conductive carbon matrix favour excellent electrochemical performance of the TiO2@carbon nanofiber electrode. The TiO2@carbon hybrid nanofibers exhibited highly reversible capacity of 206 mAh g−1 up to 100 cycles at current density of 30 mA g−1 and excellent cycling stability, indicating that the composite is a promising anode candidate for Li-ion batteries.


Enhanced Electrochemical Properties Of Lifepo4 By Mo-Substitution And Graphitic Carbon-Coating Via A Facile And Fast Microwave-Assisted Solid-State Reaction, Dan Li, Yudai Huang, Neeraj Sharma, Zhixin Chen, Dianzeng Jia, Zaiping Guo Jan 2012

Enhanced Electrochemical Properties Of Lifepo4 By Mo-Substitution And Graphitic Carbon-Coating Via A Facile And Fast Microwave-Assisted Solid-State Reaction, Dan Li, Yudai Huang, Neeraj Sharma, Zhixin Chen, Dianzeng Jia, Zaiping Guo

Faculty of Engineering - Papers (Archive)

A composite cathode material for lithium ion battery applications, Mo-doped LiFePO4/C, is obtained through a facile and fast microwave-assisted synthesis method. Rietveld analysis of LiFePO4-based structural models using synchrotron X-ray diffraction data shows that Mo-ions substitute onto the Fe sites and displace Fe-ions to the Li sites. Supervalent Mo6+ doping can act to introduce Li ion vacancies due to the charge compensation effect and therefore facilitate lithium ion diffusion during charging/discharging. Transmission electron microscope images demonstrate that the pure and doped LiFePO4 nanoparticles were uniformly covered by an approximately 5 nm thin layer of graphitic carbon. Amorphous carbon on the …


Electrical And Thermoelectric Properties Of Single-Wall Carbon Nanotube Doped Bi2te3, Y Zhang, Xiaolin Wang, W K. Yeoh, R K. Zeng, C Zhang Jan 2012

Electrical And Thermoelectric Properties Of Single-Wall Carbon Nanotube Doped Bi2te3, Y Zhang, Xiaolin Wang, W K. Yeoh, R K. Zeng, C Zhang

Faculty of Engineering - Papers (Archive)

The effects of single-wall carbon nanotube (SWCNT) doping in n-type Bi2Te3 bulk samples on the electrical and thermal transport properties have been studied. Bi2Te3 samples doped with 0–5 wt. % SWCNTs were fabricated using solid state reaction and investigated using x-ray diffraction, transmission electron microscopy, and magneto transport measurements. Results show that the 0.5% doping results in the significant enhancement of the Seebeck coefficience to as high as -231.8 lV/K, giant magneto resistance of up to 110%, reduction of thermal conductivity, and change of sign of the Seebeck coefficient from n to p type depending on the doping level and …


Precipitation Behavior Of Magnetite In Oxide Scale During Cooling Of Microalloyed Low Carbon Steel, Xianglong Yu, Zhengyi Jiang, Daijun Yang, Dongbin Wei, Quan Yang Jan 2012

Precipitation Behavior Of Magnetite In Oxide Scale During Cooling Of Microalloyed Low Carbon Steel, Xianglong Yu, Zhengyi Jiang, Daijun Yang, Dongbin Wei, Quan Yang

Faculty of Engineering - Papers (Archive)

Precipitation behavior of magnetite particles in the thermal grown oxide scale during isothermal cooling of microalloyed low carbon steel was studied using scanning electron microscopy (SEM) and thin film X-ray. The oxide scale was generated from Gleeble 3500 Thermal-Mechanical Simulator connected with a humid air generator, to simulate 550 and 450°C isothermal treatments. Several types of magnetite precipitates were observed during different cooling processes with respect to the possible mechanisms of precipitation have been discussed. It is found that magnetite particles is as a result of pro-eutectoid precipitation from oxygen-rich wustite, and also as a product of the partial decomposition …


Tio2(B)@Carbon Composite Nanowires As Anode For Lithium Ion Batteries With Enhanced Reversible Capacity And Cyclic Performance, Zunxian Yang, Guodong Du, Zaiping Guo, Xuebin Yu, Zhixin Chen, Tailiang Guo, Hua-Kun Liu Jan 2011

Tio2(B)@Carbon Composite Nanowires As Anode For Lithium Ion Batteries With Enhanced Reversible Capacity And Cyclic Performance, Zunxian Yang, Guodong Du, Zaiping Guo, Xuebin Yu, Zhixin Chen, Tailiang Guo, Hua-Kun Liu

Faculty of Engineering - Papers (Archive)

Novel TiO2(B)@carbon composite nanowires were simply prepared by a two-step hydrothermal process with subsequent heat treatment in argon. The nanostructures exhibit the unique feature of having TiO2(B) encapsulated inside and an amorphous carbon layer coating the outside. The unique core/shell structure and chemical composition is likely to lead to perfect performance in many applications. In this paper, the results of Li-ion battery testing are presented to demonstrate the superior cyclic performance and rate capability of the TiO2(B)@carbon nanowires. The composite nanowires exhibit a high reversible capacity of 560 mAh g−1 after 100 cycles …


The Behaviour Of Carbon Fibre Reinforced Polymer Confined Concrete Cylinders Under High Temperature Exposure, Butje Alfonsius Louk Fanggi, Muhammad N. S Hadi Jan 2011

The Behaviour Of Carbon Fibre Reinforced Polymer Confined Concrete Cylinders Under High Temperature Exposure, Butje Alfonsius Louk Fanggi, Muhammad N. S Hadi

Faculty of Engineering - Papers (Archive)

This study investigates the effect of temperature on the behaviour of concrete cylinders wrapped with Carbon Fibre Reinforced Polymer (CFRP). The study used nine concrete cylinders in three groups; the first group was exposed to room temperature of approximately 20ºC, the second group was exposed to a cyclic temperature with a temperature range of 20ºC to 70ºC, and the third group was exposed to a prolonged temperature of 70ºC. All cylinders were then tested to failure. The study indicated that ultimate strength of cylinders wrapped with one and two layers of CFRP are significantly unchanged after being exposed to 20ºC …


Simultaneous Activated Carbon Adsorption Within A Membrane Bioreactor For An Enhanced Micropollutant Removal, Xueqing Li, Faisal I. Hai, Long Nghiem Jan 2011

Simultaneous Activated Carbon Adsorption Within A Membrane Bioreactor For An Enhanced Micropollutant Removal, Xueqing Li, Faisal I. Hai, Long Nghiem

Faculty of Engineering - Papers (Archive)

Significant adsorption of sulfamethoxazole and carbamazepine to powdered activated carbon (PAC) was confirmed by a series of adsorption tests. In contrast, adsorption of these micropollutants to the sludge was negligible. The removal of these compounds in membrane bioreactor (MBR) was dependent on their hydrophobicity and loading as well as the PAC dosage. Sulfamethoxazole exhibited better removal rate during operation under no or low (0.1 g/L) PAC dosage. When the PAC concentration in MBR was raised to 1.0 g/L, a sustainable and significantly improved performance in the removal of both compounds was observed – the removal efficiencies of sulfamethoxazole and carbamazepine …


High-Surface-Area -Fe2o3/Carbon Nanocomposite: One-Step Synthesis And Its Highly Reversible And Enhanced High-Rate Lithium Storage Properties, S X. Dou, David Wexler, Jiazhao Wang, Hua-Kun Liu, Konstantin K. Konstantinov, Chao Zhong, Shulei Chou Jan 2010

High-Surface-Area -Fe2o3/Carbon Nanocomposite: One-Step Synthesis And Its Highly Reversible And Enhanced High-Rate Lithium Storage Properties, S X. Dou, David Wexler, Jiazhao Wang, Hua-Kun Liu, Konstantin K. Konstantinov, Chao Zhong, Shulei Chou

Faculty of Engineering - Papers (Archive)

Hollow-structured α-Fe2O3/carbon (HIOC) nanocomposite with a high surface area of around 260 m2 g−1 was synthesized by a one-step, in situ, and industrially-oriented spray pyrolysis method using iron lactate and sucrose solution as the precursors. The small α-Fe2O3 nanocrystals were highly dispersed inside amorphous carbon to form a carbon nanocomposite. Electrochemical measurements showed that the carbon played an important role in affecting both the cycle life and the rate capability of the electrode. The HIOC composites showed the best electrochemical performance in terms of high capacity (1210 mAh g−1 …


Correlation Of Nanoindentation-Induced Deformation Microstructures In Diamondlike Carbon Coatings On Silicon Substrates With Simulation Studies, Ayesha J. Haq, Paul G. Munroe, Mark Hoffman, Phil J. Martin, Avi Bendavid Jan 2010

Correlation Of Nanoindentation-Induced Deformation Microstructures In Diamondlike Carbon Coatings On Silicon Substrates With Simulation Studies, Ayesha J. Haq, Paul G. Munroe, Mark Hoffman, Phil J. Martin, Avi Bendavid

Faculty of Engineering - Papers (Archive)

The effect of the presence of diamondlike carbon coatings deposited on (100) Si substrateson the deformation mechanisms operating in the silicon substrate during contact loadinghave been investigated by both cross-sectional transmission electron microscopy andmodeling of the stresses generated beneath the indenter tip. The observed subsurfacemicrostructures were correlated to the Tresca shear stress and the hydrostatic stressgenerated in the silicon substrate beneath the indenter tip. The presence of the coatingaltered the stresses generated in the substrate, and changed the deformation mechanismfrom one of principally phase transformation in uncoated Si to predominantly dislocationmotion in the silicon substrate for the diamondlike C¿Si system. …


Silicon/Single-Walled Carbon Nanotube Composite Paper As A Flexible Anode Material For Lithium Ion Batteries, Shulei Chou, Yue Zhao, Jiazhao Wang, Zhixin Chen, Hua-Kun Liu, S. X. Dou Jan 2010

Silicon/Single-Walled Carbon Nanotube Composite Paper As A Flexible Anode Material For Lithium Ion Batteries, Shulei Chou, Yue Zhao, Jiazhao Wang, Zhixin Chen, Hua-Kun Liu, S. X. Dou

Faculty of Engineering - Papers (Archive)

Flexible silicon/single-walled carbon nanotube (Si/SWCNT) composite paper was prepared using the pulsed laser deposition (PLD) method to deposit Si onto SWCNT paper. In the composite, Si mainly shows nanoworm-like morphology. Increasing deposition time results in an increased amount of Si microspheres. Electrochemical measurements show that the capacity of the composite paper is improved by the presence of Si. The Si/SWCNT composite with only 2.2% Si shows a capacity of 163 mA h g−1 at a current density of 25 mA g−1 up to 50 cycles, which is more than 60% improvement of the capacity of pristine CNT paper. …


Controlled Synthesis Of Polyaniline Inside Mesoporous Carbon For Electroanalytical Sensors, Shenmin Zhu, Jiajun Gu, Junping Dong, Xinye Liu, Zhixin Chen, Chenxin Chen, Di Zhang Jan 2010

Controlled Synthesis Of Polyaniline Inside Mesoporous Carbon For Electroanalytical Sensors, Shenmin Zhu, Jiajun Gu, Junping Dong, Xinye Liu, Zhixin Chen, Chenxin Chen, Di Zhang

Faculty of Engineering - Papers (Archive)

A novel electroanalytical system was developed using polyaniline (PANI) functionalized ordered mesoporous carbon (CMK-3). Hydrophilic surface modification of CMK-3 is necessary and enables monomers to penetrate the pore channels of CMK-3, which makes it possible for the formation of PANI layers inside the pores of CMK-3 via in situ polymerization. The structures of the surface-modified ordered mesoporous carbon (m-CMK-3) and the PANI functionalized composites (CMK-PANIs) were characterized by X-ray diffraction, thermal gravimetric analysis, Fourier transform-infrared spectroscopy, transmission electron microscopy, and N2 adsorption measurements. The catalytic effect of the resultant CMK-PANI composite electrodes with various PANI loadings on the hydroquinone/quinine …


Influence Of Shielding Gas On Fume Formation Rate For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel, Kristin R. Carpenter, Brian J. Monaghan, John Norrish Jan 2009

Influence Of Shielding Gas On Fume Formation Rate For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel, Kristin R. Carpenter, Brian J. Monaghan, John Norrish

Faculty of Engineering - Papers (Archive)

Shielding gas composition is an important parameter for successful gas metal arc welding (GMAW) and has been shown to affect the fume formation rate (FFR). The present paper compares thirteen shielding gases and their impact on FFR in spray transfer. In Ar-based mixtures, increasing CO2 had a greater impact than raising O2 on FFR. When O2 was increased in ternary mixtures, the FFR increased for Ar-5%CO2 but no discernable increase was observed for the Ar-12%CO2 mixtures. Ar-He-CO2 mixtures had the most stable FFR's. The FFR for 100% CO2 was significantly higher due to the change in weld transfer mode to …


Analysis Of Fume Formation Rate And Fume Particle Composition For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel Using Different Shielding Gas Compositions, Kristin R. Carpenter, Brian J. Monaghan, John Norrish Jan 2009

Analysis Of Fume Formation Rate And Fume Particle Composition For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel Using Different Shielding Gas Compositions, Kristin R. Carpenter, Brian J. Monaghan, John Norrish

Faculty of Engineering - Papers (Archive)

The present paper compares thirteen shielding gases and their impact on FFR and fume particle while welding in the spray transfer regime. There was no obvious influence from the shielding gas on particle composition and fume particles were identified as (Fe,Mn)3O4. There was a slight peak shift that indicated that small levels of Mn, as detected by TEM-EDS, substituted for Fe in the Fe3O4 phase. Shielding gas composition is an important parameter for successful gas metal arc welding (GMAW) and has been shown to affect the fume formation rate (FFR). In Ar-based mixtures, increasing CO2 had a greater impact than …


Carbon Nanotube Network Modified Carbon Fibre Paper For Li Ion Batteries, Jun Chen, Jiazhao Wang, Andrew I. Minett, Yong Liu, Carol M. Lynam, Hua-Kun Liu, G G. Wallace Jan 2009

Carbon Nanotube Network Modified Carbon Fibre Paper For Li Ion Batteries, Jun Chen, Jiazhao Wang, Andrew I. Minett, Yong Liu, Carol M. Lynam, Hua-Kun Liu, G G. Wallace

Faculty of Engineering - Papers (Archive)

Here we report on the direct deposition of large quantities of highly porous carbon nanotube networks onto a carbon fibre paper support; subsequently utilised as the anode in a Li-ion battery application showing improved long-term performance and chemical stability with a significant fully reversible capacity of 546mAh/g.


Effect Of Processing Schedule On The Microstructure And Texture Of 0.78wt% Cr Extra-Low-Carbon Steel, Elena V. Pereloma, Azdiar A. Gazder, John J. Jonas, Michael K. Miller, Christopher Hj Davies Jan 2008

Effect Of Processing Schedule On The Microstructure And Texture Of 0.78wt% Cr Extra-Low-Carbon Steel, Elena V. Pereloma, Azdiar A. Gazder, John J. Jonas, Michael K. Miller, Christopher Hj Davies

Faculty of Engineering - Papers (Archive)

An extra-low-carbon steel was alloyed with 0.78 wt% Cr and subjected to three different processing schedules involving: (i) warm rolling to 65 % reduction at 640°C, (ii) warm rolling to 80% reduction at 580°C and (iii) warm rolling to 65% reduction at 640°C followed by cold rolling to 40% reduction. Increasing the severity of the deformation resulted in an increase in the number of grains containing in-grain shear bands. X-ray bulk texture analysis indicates that the g -fibre intensity was slightly higher in the steel warm rolled at 580°C than at 640°C and after cold rolling. Transmission electron microscopy and …


Carbon Nanotube Electroactive Polymer Materials: Opportunities And Challenges, Liangti Qu, Qiang Peng, Liming Dai, Geoffrey M. Spinks, G G. Wallace, Ray H. Baughman Jan 2008

Carbon Nanotube Electroactive Polymer Materials: Opportunities And Challenges, Liangti Qu, Qiang Peng, Liming Dai, Geoffrey M. Spinks, G G. Wallace, Ray H. Baughman

Faculty of Engineering - Papers (Archive)

Carbon nanotubes (CNTs) with macroscopically ordered structures (e.g., aligned or patterned mats, fibers, and sheets) and associated large surface areas have proven promising as new CNT electroactive polymer materials (CNT-EAPs) for the development of advanced chemical and biological sensors. The functionalization of CNTs with many biological species to gain specific surface characteristics and to facilitate electron transfer to and from them for chemical- and bio-sensing applications is an area of intense research activity. Mechanical actuation generated by CNT-EAPs is another exciting electroactive function provided by these versatile materials. Controlled mechanical deformation for actuation has been demonstrated in CNT mats, fibers, …


Texture Evolution During Annealing Of Warm Rolled Cr-Containing Low Carbon Steels, E V. Pereloma, Azdiar A. Gazder, John J. Jonas, Chris H. J. Davies Jan 2007

Texture Evolution During Annealing Of Warm Rolled Cr-Containing Low Carbon Steels, E V. Pereloma, Azdiar A. Gazder, John J. Jonas, Chris H. J. Davies

Faculty of Engineering - Papers (Archive)

Two low carbon steels alloyed with 0.48wt% and 0.78wt% Cr were warm rolled to 65% reduction at 640°C. Annealing was carried out at 710°C to achieve a range of recrystallized volume fractions up to 100%. Texture analysis was performed by X-ray diffraction and Electron Back Scattering Diffraction. During the initial stages of recrystallization, more recrystallized grains nucleated at shear bands than at grain boundaries in the 0.48wt%Cr steel, whereas this was not the case in the 0.78wt%Cr steel. This is associated with a decrease in the propensity to form shear bands due to the lower amount of C in solid …


Impurity Mediated In Absorption Continuum In Single Walled Carbon Nanotubes, Chao Zhang, J. C. Cao, Xiao-Bing Guo, Feng T. Liu Jan 2007

Impurity Mediated In Absorption Continuum In Single Walled Carbon Nanotubes, Chao Zhang, J. C. Cao, Xiao-Bing Guo, Feng T. Liu

Faculty of Engineering - Papers (Archive)

The authors demonstrate that in single-walled carbon nanotubes, a weak impurity potential can leadto a strong above-gap absorption continuum. The total absorption is enhanced due to the intrabandand indirect transitions, as well as plasmon excitations, which are forbidden in perfect nanotubes.Such impurity induced absorption is strongly dependent on the size and chirality of the tube.


Amorphous Carbon-Coated Silicon Nanocomposites: A Low-Temperature Synthesis Via Spray Pyrolysis And Their Application As High-Capacity Anodes For Lithium-Ion Batteries, See How Ng, Jiazhao Wang, David Wexler, Sau Yen Chew, Hua-Kun Liu Jan 2007

Amorphous Carbon-Coated Silicon Nanocomposites: A Low-Temperature Synthesis Via Spray Pyrolysis And Their Application As High-Capacity Anodes For Lithium-Ion Batteries, See How Ng, Jiazhao Wang, David Wexler, Sau Yen Chew, Hua-Kun Liu

Faculty of Engineering - Papers (Archive)

This article introduces an effective, inexpensive, and industrially oriented approach to produce carbon-coated Si nanocomposites as high-capacity anode materials for use in rechargeable lithium-ion batteries. Initially, nanosized Si particles (nm) were mixed in a citric acid/ethanol solution via ultrasonication. This mixture was further spray-pyrolyzed in air at low processing temperature (300-500 C), resulting in a homogeneous layer of carbon coating on the surface of the spheroidal Si nanoparticles. The effects of the processing temperature on the amorphous carbon content, the thickness of the carbon-coating layer, and the homogeneity of the carbon coating were studied in detail. These parameters strongly influenced …


Continuous Unidirectional Carbon Fibre-Reinforced Concrete Beams, Manouch Salehi, Muhammad N. S Hadi Jan 2007

Continuous Unidirectional Carbon Fibre-Reinforced Concrete Beams, Manouch Salehi, Muhammad N. S Hadi

Faculty of Engineering - Papers (Archive)

This paper reports a set of experimental results for continuous unidirectional carbonfibre-reinforced concrete beams. The fibers are embedded at different layers in thetension side of the beam below the neutral axis. All together nine concrete beamswere constructed and tested, three of which contained no reinforcement. The carbonfibre-reinforced concrete beam load-deflection results are presented graphically forthree beams with one-layer, one with two-layers and two with four-layers ofcontinuous unidirectional fibres. The maximum deflections of the reinforced beamsare compared with those of plain concrete beams.


Polyaniline And Polyaniline-Carbon Nanotube Composite Fibres As Battery Materials In Ionic Liquid Electrolyte, Caiyun Y. Wang, Vahid Mottaghitalab, Chee O. Too, Geoffrey M. Spinks, G G. Wallace Jan 2007

Polyaniline And Polyaniline-Carbon Nanotube Composite Fibres As Battery Materials In Ionic Liquid Electrolyte, Caiyun Y. Wang, Vahid Mottaghitalab, Chee O. Too, Geoffrey M. Spinks, G G. Wallace

Faculty of Engineering - Papers (Archive)

New battery materials are presented that consist of either a solid polyaniline (PANi) fibre or the same fibre containing carbon nanotubes (CNTs). An ionic liquid ethylmethyl imidazolium bis(trifluoromethanesulfonyl) amide (EMI.TFSA) is used as electrolyte. The electrochemical properties of PANi and PANi/CNT fibres are investigated by means of cyclic voltammetry, a.c. impedance and galvanostatic charge–discharge techniques. A PANi fibre with a CNT content of 0.25 wt.% exhibits a discharge capacity of 12.1 mAh g−1.


In-Situ Observation Of Sulfide Precipitation In A Low-Carbon, Titanium Alloyed Steel, Sima Aminorroaya-Yamini, Rian J. Dippenaar, Mark H. Reid Jan 2006

In-Situ Observation Of Sulfide Precipitation In A Low-Carbon, Titanium Alloyed Steel, Sima Aminorroaya-Yamini, Rian J. Dippenaar, Mark H. Reid

Faculty of Engineering - Papers (Archive)

Removal of inclusions is of greatsignificance to steelmakers and the scientific principles underpinning inclusion removal has been the subject of numerous investigations in the past and during the last few decades, it has become increasingly obvious that inclusions can be utilized as an effective tool for the control of microstructure1 . Manganese sulfide precipitates are known to crystallize and precipitate preferentially in interdendritic regions during solidification, due to segregation of manganese and sulphur2 and these inclusions have traditionally been used for the dual purpose of improving the machinability and controlling of grain structure in steel. Small MnS particles restrain grain …


Delta-Ferrite Recovery Structures In Low Carbon Steels, Rian J. Dippenaar, Dominic J. Phelan Jan 2002

Delta-Ferrite Recovery Structures In Low Carbon Steels, Rian J. Dippenaar, Dominic J. Phelan

Faculty of Engineering - Papers (Archive)

The development of delta-ferrite recovery sub-structures in low carbon steels has been observed in-situ utlhsing laser scanniJlg confocal microscopy (LSCM). Well developed subboundaries with interfaCial' energies much smaller than that of delta-fen'ite grain boundaries fOfmed following transformation from austenite to delta-fen'ite on heating. Transfonnatioll stresses associated with the austenite to delta-fenite phase transt'onnation generate dislocations that subsequently recover into sub-boundaries by a process of polygonisation. Experimental evidence in suppol1 of this proposal was found in a ferritic stainless steel. Thermal cycling through the high temperature delta-ferrite/austenite/delta-fel1'ite phase b'ansformation leads to the development of a strong recovery substructure, wh.ich in turn. …