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Full-Text Articles in Engineering
Large Scale Synthesis Of V-Shaped Rutile Twinned Nanorods, Weigang Lu, Britain Bruner, Gilberto Casillas, Jibao He, Miguel Jose-Yacaman, Patrick J. Farmer
Large Scale Synthesis Of V-Shaped Rutile Twinned Nanorods, Weigang Lu, Britain Bruner, Gilberto Casillas, Jibao He, Miguel Jose-Yacaman, Patrick J. Farmer
Australian Institute for Innovative Materials - Papers
V-shaped rutile twinned nanorods (VRTNs) with different aspect ratios were synthesized on large scale using a one-pot organic solvothermal method. Although several different types of VRTNs were produced, (101) twinned nanorods were the major product with minor amounts of (301) twins and straight nanorods. STEM, TEM and XRD characterizations show that [001] is the growth direction of VRTNs, with surfaces dominated by {110} facets. Intermediate formation of both brookite and anatase nanorods provides dual pathways to VRTNs’ growth: one path in which anatase seeds trigger and promote brookite nanorod growth; and a second path in which anatase nanorods are formed …
Hollow Nitrogen Containing Core/Shell Fibrous Carbon Nanomaterials As Support To Platinum Nanocatalysts And Their Tem Tomography Study, Cuifeng Zhou, Zongwen Liu, Xusheng Du, David Rg Mitchell, Yiu-Wing Mai, Yushan Yan, Simon Peter Ringer
Hollow Nitrogen Containing Core/Shell Fibrous Carbon Nanomaterials As Support To Platinum Nanocatalysts And Their Tem Tomography Study, Cuifeng Zhou, Zongwen Liu, Xusheng Du, David Rg Mitchell, Yiu-Wing Mai, Yushan Yan, Simon Peter Ringer
Australian Institute for Innovative Materials - Papers
Core/shell nanostructured carbon materials with carbon nanofiber (CNF) as the core and a nitrogen (N)-doped graphitic layer as the shell were synthesized by pyrolysis of CNF/polyaniline (CNF/PANI) composites prepared by in situ polymerization of aniline on CNFs. High-resolution transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared and Raman analyses indicated that the PANI shell was carbonized at 900 degress C. Platinum (Pt) nanoparticles were reduced by formic acid with catalyst supports. Compared to the untreated CNF/ PANI composites, the carbonized composites were proven to be better supporting materials for the Pt nanocatalysts and showed superior performance as catalyst …
The Problem Of Road Congestion: The Fultility Of 'Avoidable Cost' Estimates, Mark D. Harrison
The Problem Of Road Congestion: The Fultility Of 'Avoidable Cost' Estimates, Mark D. Harrison
Australian Institute for Innovative Materials - Papers
The Bureau of Infrastructure, Transport and Regional Economics estimates of the costs of road congestion in Australian capital cities ($9.4 billion in 2005 and projected to more than double by 2020) are widely cited. But these projections appear to overstate the problem and provide little, if any, guidance for sound policy development. They are not measures of the net gain from introducing congestion charging. Moreover, such numbers provide no help for evaluating the net benefits of other policies to deal with congestion, such as increasing road capacity. Without efficiency-based cost-benefit analysis of all policies to deal with road congestion, governments …
Parameters Controlling Emission Of Terahertz Frequency Electromagnetic Radiation From Inas And Gaas: An Ensemble Monte Carlo Simulation Study, David Laurence Cortie, Roger A. Lewis
Parameters Controlling Emission Of Terahertz Frequency Electromagnetic Radiation From Inas And Gaas: An Ensemble Monte Carlo Simulation Study, David Laurence Cortie, Roger A. Lewis
Australian Institute for Innovative Materials - Papers
The generation, manipulation and detection of terahertz-frequency electromagnetic radiation are topics of great current theoretical and experimental interest. In particular, the coherent generation and detection of ultrashort pulses of terahertz radiation has opened up the field of terahertz time-domain spectroscopy, which permits the simultaneous measurement of amplitude and phase of the terahertz electric field. In this paper, the emission of terahertz radiation from bare semiconductor surfaces following photoexcitation by ultrashort pulses of near-infrared radiation is studied using ensemble Monte Carlo simulations. The simulation allows us to examine separately distinct scattering mechanisms and to vary the materials parameters of bandgap, absorption …
Power To You: Carbon Nanotube Muscles Are Going Strong, Geoffrey M. Spinks
Power To You: Carbon Nanotube Muscles Are Going Strong, Geoffrey M. Spinks
Australian Institute for Innovative Materials - Papers
Just on a year ago my colleagues and I announced our discovery that carbon nanotube yarns could be made to twist and rotate at great speeds when electrically stimulated. In this way we had created "artificial muscles" that could change their shape in response to stimulus.
Anti And Gauche Conformers Of An Inorganic Butane Analogue, Nh3bh2nh2bh3, Xuenian Chen, Judith C. Gallucci, Charles Campana, Zhenguo Huang, Hima Kumar Lingam, Sheldon G. Shore, Ji-Cheng Zhao
Anti And Gauche Conformers Of An Inorganic Butane Analogue, Nh3bh2nh2bh3, Xuenian Chen, Judith C. Gallucci, Charles Campana, Zhenguo Huang, Hima Kumar Lingam, Sheldon G. Shore, Ji-Cheng Zhao
Australian Institute for Innovative Materials - Papers
The crystal structures of an inorganic butane analogue, NH3BH2NH2BH3 (DDAB), were determined using single crystal X-ray diffraction, revealing both anti and gauche conformations. The anti conformation is stabilized by intermolecular dihydrogen bonds in the crystal whereas two gauche conformations of DDAB observed in its 18-crown-6 adducts are stabilized by an intramolecular dihydrogen bond. The two gauche conformations show rotational isomerization but whether they are a pair of enantiomers is yet to be defined.
A Multimodal Optical And Electrochemical Device For Monitoring Surface Reactions: Redox Active Surfaces In Porous Silicon Rugate Filters, Simone Ciampi, Bin Guan, Nadim A. Darwish, Ying Zhu, Peter J. Reece, J Justin Gooding
A Multimodal Optical And Electrochemical Device For Monitoring Surface Reactions: Redox Active Surfaces In Porous Silicon Rugate Filters, Simone Ciampi, Bin Guan, Nadim A. Darwish, Ying Zhu, Peter J. Reece, J Justin Gooding
Australian Institute for Innovative Materials - Papers
Herein, mesoporous silicon (PSi) is configured as a single sensing device that has dual readouts; as a photonic crystal sensor in a Rugate filter configuration, and as a high surface area porous electrode. The as-prepared PSi is chemically modified to provide it with stability in aqueous media and to allow for the subsequent coupling of chemical species, such as via Cu(i)-catalyzed cycloaddition reactions between 1-alkynes and azides ("click" reactions). The utility of the bimodal capabilities of the PSi sensor for monitoring surface coupling procedures is demonstrated by the covalent coupling of a ferrocene derivative, as well as by demonstrating ligand-exchange …
Electroacoustic Response Of 1-3 Piezocomposite Transducers For High Power Applications, Hyeong Jae Lee, Shujun Zhang, Xuecang Geng, Thomas R. Shrout
Electroacoustic Response Of 1-3 Piezocomposite Transducers For High Power Applications, Hyeong Jae Lee, Shujun Zhang, Xuecang Geng, Thomas R. Shrout
Australian Institute for Innovative Materials - Papers
The electroacoustic performance of 1-3 piezoelectric composite transducers with low loss polymer filler was studied and compared to monolithic Pb(Zr,Ti)O 3 (PZT) piezoelectric transducers. The 1-3 composite transducers exhibited significantly high electromechanical coupling factor (k t ∼ 0.64) when compared to monolithic counterparts (k t ∼ 0.5), leading to the improved bandwidth and loop sensitivity, being on the order of 67% and -24.0 dB versus 44% and -24.8 dB, respectively. In addition, the acoustic output power and transmit efficiency (∼50%) were found to be comparable to the monolithic PZT transducers, demonstrating potential for broad bandwidth, high power ultrasonic transducer applications.
High Performance Ferroelectric Relaxor-Pbtio3 Single Crystals: Status And Perspective, Shujun Zhang, Fei Li
High Performance Ferroelectric Relaxor-Pbtio3 Single Crystals: Status And Perspective, Shujun Zhang, Fei Li
Australian Institute for Innovative Materials - Papers
Ferroelectrics are essential components in a wide range of applications, including ultrasonic transducers, sensors, and actuators. In the single crystal form, relaxor-PbTiO3 (PT) piezoelectric materials have been extensively studied due to their ultrahigh piezoelectric and electromechanical properties. In this article, a perspective and future development of relaxor-PT crystals are given. Initially, various techniques for the growth of relaxor-PT crystals are reviewed, with crystals up to 100 mm in diameter and 200 mm in length being readily achievable using the Bridgman technique. Second, the characterizations of dielectric and electromechanical properties are surveyed. Boundary conditions, including temperature, electric field, and stress, are …
An Efficient Way To Enhance Output Strain For Shear Mode Pb(In1/2nb1/2)O-3-Pb(Mg1/3nb2/3)O-3-Pbtio3 Crystals: Applying Uniaxial Stress Perpendicular To Polar Direction, Fei Li, Shujun Zhang, Zhuo Xu, Dabin Lin, Junjie Gao, Zhenrong Li, Linghang Wang
An Efficient Way To Enhance Output Strain For Shear Mode Pb(In1/2nb1/2)O-3-Pb(Mg1/3nb2/3)O-3-Pbtio3 Crystals: Applying Uniaxial Stress Perpendicular To Polar Direction, Fei Li, Shujun Zhang, Zhuo Xu, Dabin Lin, Junjie Gao, Zhenrong Li, Linghang Wang
Australian Institute for Innovative Materials - Papers
The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with "1T" and "2R" domain configurations, respectively, were investigated under uniaxial stress perpendicular to polar direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both "1T" and "2R" crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to polar direction, resulting in a "harder" polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was …