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Articles 1 - 12 of 12

Full-Text Articles in Engineering

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 …


Giant Enhancement In Critical Current Density, Up To A Hundredfold, In Superconducting Nafe0.97co0.03 As Single Crystals Under Hydrostatic Pressure, Babar Shabbir, Xiaolin Wang, Shaban Reza Ghorbani, A-Li Wang, S X. Dou, X.H Chen Jan 2015

Giant Enhancement In Critical Current Density, Up To A Hundredfold, In Superconducting Nafe0.97co0.03 As Single Crystals Under Hydrostatic Pressure, Babar Shabbir, Xiaolin Wang, Shaban Reza Ghorbani, A-Li Wang, S X. Dou, X.H Chen

Australian Institute for Innovative Materials - Papers

Tremendous efforts towards improvement in the critical current density "Jc" of iron based superconductors (FeSCs), especially at relatively low temperatures and magnetic fields, have been made so far through different methods, resulting in real progress. Jc at high temperatures in high fields still needs to be further improved, however, in order to meet the requirements of practical applications. Here, we demonstrate a simple approach to achieve this. Hydrostatic pressure can significantly enhance Jc in NaFe0.97Co0.03As single crystals by at least tenfold at low field and more than a hundredfold at high fields. …


Super-Paramagnetic Particles Chemically Bound To Luminescent Diamond: Single Nano-Crystals Probed With Optically Detected Magnetic Resonance, Taras Plakhotnik, Haroon Aman, Shaohua Zhang, Zhen Li Jan 2015

Super-Paramagnetic Particles Chemically Bound To Luminescent Diamond: Single Nano-Crystals Probed With Optically Detected Magnetic Resonance, Taras Plakhotnik, Haroon Aman, Shaohua Zhang, Zhen Li

Australian Institute for Innovative Materials - Papers

We have synthesized novel composite particles made of single-domain nanomagnets chemically bound to nanocrystals of diamond. Optically detected magnetic resonance spectra of nitrogen-vacancy centers in diamond allowed us to estimate the magnetic field of the nanomagnets and to observe the saturation of their magnetization when an external field of a few tens of mT has been applied. The saturation effect is in agreement with the size of the domains measured using transmission electron microscopy and a simple model of magnetization.


Single Molecular Shuttle-Junction: Shot Noise And Decoherence, Wenxi Lai, C Zhang, Zhongshui Ma Jan 2015

Single Molecular Shuttle-Junction: Shot Noise And Decoherence, Wenxi Lai, C Zhang, Zhongshui Ma

Faculty of Engineering and Information Sciences - Papers: Part A

Single molecular shuttle-junction is one kind of nanoscale electromechanical tunneling system. In this junction, a molecular island oscillates depending on its charge occupation, and this charge dependent oscillation leads to modulation of electron tunneling through the molecular island. This paper reviews recent development on the study of current, shot noise and decoherence of electrons in the single molecular shuttle-junction. We will give detail discussions on this topic using the typical system model, the theory of fully quantum master equation and the Aharonov-Bohm interferometer.


Coupled Discrete Element-Finite Difference Method For Analysing The Load-Deformation Behaviour Of A Single Stone Column In Soft Soil, Buddhima Indraratna, Ngoc Trung Ngo, Cholachat Rujikiatkamjorn, Scott W. Sloan Jan 2015

Coupled Discrete Element-Finite Difference Method For Analysing The Load-Deformation Behaviour Of A Single Stone Column In Soft Soil, Buddhima Indraratna, Ngoc Trung Ngo, Cholachat Rujikiatkamjorn, Scott W. Sloan

Faculty of Engineering and Information Sciences - Papers: Part A

Experimental studies and numerical modelling of the deformation of soft clay stabilised by stone columns have been conducted over the past few decades. Continuum-based numerical models have provided valuable insight into the prediction of settlement, lateral deformation, and stress and strain-rate dependent behaviour of stone columns at a macroscopic scale, but because they consist of granular material such as crushed rock, gravel, and waste rock aggregates, their behaviour is influenced by inter-particle micromechanics and cannot be modelled properly using these models. In this paper a novel coupled model of the discrete element method (DEM) and finite difference method (FDM) is …


In-Situ Formation And Densification Of Mgal2o4-Smalo3 Ceramics By A Single-Stage Reaction Sintering Process, Beiyue Ma, Yue Yin, Qiang Zhu, Ying Li, Guangqiang Li, Jingkun Yu Jan 2015

In-Situ Formation And Densification Of Mgal2o4-Smalo3 Ceramics By A Single-Stage Reaction Sintering Process, Beiyue Ma, Yue Yin, Qiang Zhu, Ying Li, Guangqiang Li, Jingkun Yu

Faculty of Engineering and Information Sciences - Papers: Part A

Stoichiometric magnesium aluminate spinel (MgAl2O4, MA)-samarium aluminate (SmAlO3, SA) ceramics have been prepared at 1580°C for 4h from calcined magnesia (MgO), commercial alumina (Al2O3) and samarium oxide (Sm2O3) by a single-stage in-situ reaction sintering (SIRS) method. The phase compositions, microstructures, shrinkage ratio, bulk density and cold compressive strength of the MA-SA ceramics have been investigated. The ceramics with 2.5 - 7.5 wt. % Sm2O3 are composed of MA and SA phases. The microstructures of the ceramics are dense. MA particles exist as angular …


A Survey Of Single And Multi-Hop Link Schedulers For Mmwave Wireless Systems, Jian Song, Kwan-Wu Chin Jan 2015

A Survey Of Single And Multi-Hop Link Schedulers For Mmwave Wireless Systems, Jian Song, Kwan-Wu Chin

Faculty of Engineering and Information Sciences - Papers: Part A

Wireless communication at 60. GHz, aka mmWave, provides extremely high data rates, i.e., several Gb/s. Moreover, devices have a much shorter transmission range as compared to those operating in the 2.4 and 5. GHz bands. Indeed, links can be treated as pseudo-wires with minimal interference leakage. As a result, future 60. GHz systems will have very high spatial reuse. This, however, is at the expense of high propagation loss, which can be overcome using directional or smart antennas. Another promising solution is to employ relays to boost the signal of weak links. In particular, if relays are properly selected, they …


Investigation Of X70 Line Pipe Steel Fracture During Single Edge-Notched Tensile Testing Using Acoustic Emission Monitoring, Turbadrakh Chuluunbat, Cheng Lu, Andrii Kostryzhev, A Kiet Tieu Jan 2015

Investigation Of X70 Line Pipe Steel Fracture During Single Edge-Notched Tensile Testing Using Acoustic Emission Monitoring, Turbadrakh Chuluunbat, Cheng Lu, Andrii Kostryzhev, A Kiet Tieu

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents an investigation of the fracture behavior of X70 pipeline steel using the acoustic emission (AE) monitoring technique. The AE monitoring technique is widely used in mechanical and materials research for detection of plastic deformation, fracture initiation and crack growth. However, quantitative dependences of the AE parameters (such as signal amplitude and frequency) on the fracture parameters of X70 pipeline steel (such as ductile and brittle fracture initiation and propagation) have not been studied in depth and are therefore not completely understood. In this paper, we report an investigation of the effect of loading conditions on the fracture …


Superior Intrinsic Thermoelectric Performance With Zt Of 1.8 In Single-Crystal And Melt-Quenched Highly Dense Cu2-Xse Bulks, Lanling Zhao, Xiaolin Wang, Ji-Yang Wang, Zhenxiang Cheng, S X. Dou, Jun Wang, L Liu Jan 2015

Superior Intrinsic Thermoelectric Performance With Zt Of 1.8 In Single-Crystal And Melt-Quenched Highly Dense Cu2-Xse Bulks, Lanling Zhao, Xiaolin Wang, Ji-Yang Wang, Zhenxiang Cheng, S X. Dou, Jun Wang, L Liu

Australian Institute for Innovative Materials - Papers

Practical applications of the high temperature thermoelectric materials developed so far are partially obstructed by the costly and complicated fabrication process. In this work, we put forward two additional important properties for thermoelectric materials, high crystal symmetry and congruent melting. We propose that the recently discovered thermoelectric material Cu2-xSe, with figure of merit, zT, over 1.5 at T of ~ 1000 K, should meet these requirements, based on our analysis of its crystal structure and the Cu-Se binary phase diagram. We found that its excellent thermoelectric performance is intrinsic, and less dependent on grain size, while highly dense samples can …


Terahertz Probes Of Magnetic Field Induced Spin Reorientation In Yfeo 3 Single Crystal, Xian Lin, Junjie Jiang, Zuanming Jin, Dongyang Wang, Zhen Tian, Jiaguang Han, Zhenxiang Cheng, Guohong Ma Jan 2015

Terahertz Probes Of Magnetic Field Induced Spin Reorientation In Yfeo 3 Single Crystal, Xian Lin, Junjie Jiang, Zuanming Jin, Dongyang Wang, Zhen Tian, Jiaguang Han, Zhenxiang Cheng, Guohong Ma

Australian Institute for Innovative Materials - Papers

Using the terahertz time-domain spectroscopy, we demonstrate the spin reorientation of a canted antiferromagnetic YFeO3 single crystal, by evaluating the temperature and magnetic field dependence of resonant frequency and amplitude for the quasi-ferromagnetic (FM) and quasi-antiferromagnetic modes (AFM), a deeper insight into the dynamics of spin reorientation in rare-earth orthoferrites is established. Due to the absence of 4f-electrons in Y ion, the spin reorientation of Fe sublattices can only be induced by the applied magnetic field, rather than temperature. In agreement with the theoretical predication, the frequency of FM mode decreases with magnetic field. In addition, an …


Semimetal-Semiconductor Transition And Giant Linear Magnetoresistances In Three-Dimensional Dirac Semimetal Bi0.96sb0.04 Single Crystals, Zengji Yue, Xiaolin Wang, Shi-Shen Yan Jan 2015

Semimetal-Semiconductor Transition And Giant Linear Magnetoresistances In Three-Dimensional Dirac Semimetal Bi0.96sb0.04 Single Crystals, Zengji Yue, Xiaolin Wang, Shi-Shen Yan

Australian Institute for Innovative Materials - Papers

Three-dimensional (3D) Dirac semimetals are new quantum materials and can be viewed as 3D analogues of graphene. Many fascinating electronic properties have been proposed and realized in 3D Dirac semimetals, which demonstrate their potential applications in next generation quantum devices. Bismuth-antimony Bi1− x Sb x can be tuned from a topological insulator to a band insulator through a quantum critical point at x ≈ 4%, where 3D Dirac fermions appear. Here, we report on a magnetotransport study of Bi1− x Sb x at such a quantum critical point. An unusual magnetic-field induced semimetal-semiconductor phase transition was observed in the Bi0.96Sb0.04 …


Self-Growth Of Centimeter-Scale Single Crystals By Normal Sintering Process In Modified Potassium Sodium Niobate Ceramics, Cheol-Woo Ahn, Ho-Yong Lee, Guifang Han, Shujun Zhang, Si-Young Choi, Jong-Jin Choi, Jong-Woo Kim, Woon-Ha Yoon, Joon-Hwan Choi, Dong-Soo Park, Byung-Dong Hahn, Jungho Ryu Jan 2015

Self-Growth Of Centimeter-Scale Single Crystals By Normal Sintering Process In Modified Potassium Sodium Niobate Ceramics, Cheol-Woo Ahn, Ho-Yong Lee, Guifang Han, Shujun Zhang, Si-Young Choi, Jong-Jin Choi, Jong-Woo Kim, Woon-Ha Yoon, Joon-Hwan Choi, Dong-Soo Park, Byung-Dong Hahn, Jungho Ryu

Australian Institute for Innovative Materials - Papers

In this manuscript, an interesting phenomenon is reported. That is the self-growth of single crystals in Pb-free piezoelectric ceramics. These crystals are several centimeters in size. They are grown without any seed addition through a normal sintering process in modified potassium sodium niobate ceramics. It has been achieved by the composition designed to compensate the Na + loss which occurs during the liquid phase sintering. The composition of the crystals is (K0.4925 Na0.4925-x Ba0.015+x/2)Nb 0.995+x O3 [x is determined by the Na+ loss, due to Na2O volatilization]. These crystals have high piezoelectric voltage coefficients (g33, 131 10-3 Vm/N), indicating that …