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Articles 1 - 26 of 26
Full-Text Articles in Engineering
Strategic Approaches For Management Of Risk In Geomechanics, R. Chowdhury, P. Flentje
Strategic Approaches For Management Of Risk In Geomechanics, R. Chowdhury, P. Flentje
Faculty of Engineering - Papers (Archive)
This paper outlines the challenges facing geomechanics and advocates some strategies for dealing with these challenges. Advancement of geomechanics and its application in the past may be seen in a historical context as serving the needs of society such as the development of infrastructure and natural resources. The needs of society are changing rapidly due to population growth, increasing urbanisation and globalisation. Climate change poses specially challenges, the impacts increasing with time. Therefore, development of new strategies is essential. For example, greater attention should be given to the development of interdisciplinary approaches. It is vitally important that systematic methods be …
Location Constraints In Digital Rights Management, Adam Muhlbauer, Reihaneh Safavi-Naini, Farzad Salim, Nicholas Paul Sheppard, Martin Jan Surminen
Location Constraints In Digital Rights Management, Adam Muhlbauer, Reihaneh Safavi-Naini, Farzad Salim, Nicholas Paul Sheppard, Martin Jan Surminen
Faculty of Informatics - Papers (Archive)
Digital rights management allows information owners to control the use and dissemination of electronic documents via a machine-readable licence. This paper describes the design and implementation of a system for creating and enforcing licences containing location constraints that can be used to restrict access to sensitive documents to a defined area. Documents can be loaded onto a portable device and used in the approved areas, but cannot be used if the device moves to another area. Our contribution includes a taxonomy for access control in the presence of requests to perform non-instantaneous controlled actions.
Transport And Magnetic Critical Current In Superconducting Mgb2 Wires, J. Horvat, W. K. Yeoh, J. H. Kim, S. X. Dou
Transport And Magnetic Critical Current In Superconducting Mgb2 Wires, J. Horvat, W. K. Yeoh, J. H. Kim, S. X. Dou
Faculty of Engineering - Papers (Archive)
Direct comparison of the magnetic and transport critical current density (Jc) for the same pieces of copper-sheathed MgB2 wires shows a large discrepancy in magnitude and field dependence of the two. The value of magnetic Jc can differ from the value of transport Jc by a factor of 10 or more. This discrepancy does not occur merely because of the difference in the voltage at which the magnetic and transport Jc are measured, but mainly because of the specific microstructure of MgB2. Such microstructure results in superconducting screening on at least two different length-scales, despite the absence of weak links …
From Automatic Identification And Data Capture (Aidc) To “Smart Business Process”: Preparing For A Pilot Integrating Rfid, S. F. Wamba, E. Lefebvre, Y. Bendavid, L.. A. Lefebvre
From Automatic Identification And Data Capture (Aidc) To “Smart Business Process”: Preparing For A Pilot Integrating Rfid, S. F. Wamba, E. Lefebvre, Y. Bendavid, L.. A. Lefebvre
Faculty of Informatics - Papers (Archive)
This paper examines the underlying logic behind the rules configured in a RFID middleware to support “smart business processes” in one retail supply chain. Through a detailed investigation of the underlying business processes, we will demonstrate how businesses rules can be defined, configured and refined in a RFID middleware. The results confirm that RFID technology is not a “Plug and Play” solution. RFID middleware configuration will require a high level of customization. Finally, this study allows the improvement of our understanding of the real potential of RFID technology in the supply chain context.
Proposal For A New Class Of Materials: Spin Gapless Semiconductors, Xiaolin Wang
Proposal For A New Class Of Materials: Spin Gapless Semiconductors, Xiaolin Wang
Australian Institute for Innovative Materials - Papers
The concept of the spin gapless semiconductor in which both electron and hole can be fully spin polarized is proposed, and its possibility is presented on the basis of first-principles electronic structure calculations. Possible new physics and potential applications in spintronic devices based on the spin gapless semiconductors are discussed.
Structure, Ferroelectric Properties, And Magnetic Properties Of The La-Doped Bismuth Ferrite, Zhenxiang Cheng, Aihua Li, Xiaolin Wang, S X. Dou, Kiyoshi Ozawa, Hideo Kimura, S Zhang, Thomas R. Shrout
Structure, Ferroelectric Properties, And Magnetic Properties Of The La-Doped Bismuth Ferrite, Zhenxiang Cheng, Aihua Li, Xiaolin Wang, S X. Dou, Kiyoshi Ozawa, Hideo Kimura, S Zhang, Thomas R. Shrout
Australian Institute for Innovative Materials - Papers
Bi1-xLaxFeO3 ceramics with x=0, 0.1, 0.2, and 0.3 have been synthesized by solid state reaction, starting from metal oxides. A series of structure transformations is found to depend upon the doping level. Below 10% La doping, Bi1-xLaxFeO3 maintains the rhombohedral structure of BiFeO3. However, for Bi0.8La0.2FeO3 and Bi0.7La0.3FeO3, the structures change to the orthorhombic and tetragonal, respectively. La doping significantly reduces electric leakage and leads to successful observation of electrical polarization hysteresis loops. Doping with La also …
Reduction Of Superconducting Transition Temperature And Flux Pinning In Al And C Codoped Mgb2 With Insight From First-Principles Calculations, Aihua Li, Xiaolin Wang, S X. Dou, Qiwen Yao, Zhenxiang Cheng, Saeid Soltanian, J M. Yoo, P Munroe
Reduction Of Superconducting Transition Temperature And Flux Pinning In Al And C Codoped Mgb2 With Insight From First-Principles Calculations, Aihua Li, Xiaolin Wang, S X. Dou, Qiwen Yao, Zhenxiang Cheng, Saeid Soltanian, J M. Yoo, P Munroe
Australian Institute for Innovative Materials - Papers
We report for the first time the Al and C codoping effect on the structures and superconductivity in MgB2. It was found that both the lattice parameters and the Tc decreased monotonically with increasing doping level of both Al and C. The Tc dropped to 27.5 and 7 K for x=0.2 and for x =0.4, respectively. The reduction of Tc for the codoping was found to be quicker than for individual Al doping and slower than for individual C doping at the same doping levels. First-principles calculations indicated that the observed decrease in Tc …
Excess Mg Addition Mgb2 /Fe Wires With Enhanced Critical Current Density, Rong Zeng, Lin Lu, Wenxian Li, Jianli Wang, Dongqi Shi, Josip Horvat, S X. Dou, M Bhatia, M D Sumption, Edward W. Collings, Jaimoo Yoo, Mike Tomsic, M Rindfleisch
Excess Mg Addition Mgb2 /Fe Wires With Enhanced Critical Current Density, Rong Zeng, Lin Lu, Wenxian Li, Jianli Wang, Dongqi Shi, Josip Horvat, S X. Dou, M Bhatia, M D Sumption, Edward W. Collings, Jaimoo Yoo, Mike Tomsic, M Rindfleisch
Australian Institute for Innovative Materials - Papers
MgB2 /Fe wires with 10 at. % excess Mg produced by in situ powder-in-tube processing werecompared to normal stoichiometric MgB2 /Fe wires prepared by the same method. It was found thatthe critical current density Jc and the irreversibility field (Hirr) were significantly enhanced forMgB2 /Fe wires with excess Mg. The transport Jc for 10 at. % Mg excess samples sintered at 800 degrees C, measured at a field of up to 14 T, increased by a factor of 2 compared to that for the normal MgB2 wires. The best Jc results …
Improved Ferroelectric Properties In Multiferroic Bifeo3 Thin Films Through La And Nb Codoping, Zhenxiang Cheng, Xiaolin Wang, S X. Dou, Hideo Kimura, Kiyoshi Ozawa
Improved Ferroelectric Properties In Multiferroic Bifeo3 Thin Films Through La And Nb Codoping, Zhenxiang Cheng, Xiaolin Wang, S X. Dou, Hideo Kimura, Kiyoshi Ozawa
Australian Institute for Innovative Materials - Papers
We report the significant improvement of the ferroelectric properties of BiFeO3thin film through control of electrical leakage by Nb doping. A very large remanent electrical polarization value of 80 µC/cm2 was observed in Bi0.8La0.2Nb0.01Fe0.99O3 thin film on Pt/Ti/SiO2/Si substrate. The doping effect of Nb in reducing the movable charge density due to oxygen vacancies in BiFeO3 was confirmed by the dielectric measurements. A very small loss was observed in the Nb and La codoped BiFeO3 thin film. As well as the improvement in the …
Flux-Pinning Mechanism In Silicone-Oil Doped Mgb2: Evidence For Charge-Carrier Mean Free Path Fluctuation Pinning, Shaban R. Ghorbani, Xiaolin Wang, S X. Dou, Sung-Ik Lee, Md S. Hossain
Flux-Pinning Mechanism In Silicone-Oil Doped Mgb2: Evidence For Charge-Carrier Mean Free Path Fluctuation Pinning, Shaban R. Ghorbani, Xiaolin Wang, S X. Dou, Sung-Ik Lee, Md S. Hossain
Australian Institute for Innovative Materials - Papers
Flux-pinning mechanism of MgB2 doped with 10 wt % silicone-oil sintered at low and high temperatures has been investigated by magnetic measurements. The field dependence of the critical current density, jc(B), was analysed within the collective pinning model. A crossover field, Bsb, from the single vortex to the small vortex bundle-pinning regime was observed. For both types of sintered samples, the temperature dependence of Bsb(T) at low temperature is in good agreement with the δl pinning mechanism, i.e., pinning associated with charge-carrier mean free path fluctuation. At temperatures close to the critical …
High Field Performance Of Nano-Diamond Doped Mgb2 Superconductor, Arpita Vajpayee, V P. Awana, H Kishan, Anant Narlikar, G L. Bhalla, Xiaolin Wang
High Field Performance Of Nano-Diamond Doped Mgb2 Superconductor, Arpita Vajpayee, V P. Awana, H Kishan, Anant Narlikar, G L. Bhalla, Xiaolin Wang
Australian Institute for Innovative Materials - Papers
The results from magnetotransport and magnetization of nanodiamond doped MgB2-nDx are reported. Superconducting transition temperature (Tc) is not affected significantly by x up to x =0.05 and latter decreases slightly for higher x>0.05. R(T) vs H measurements show higher Tc values under same applied magnetic fields for the nanodiamond added samples, resulting in higher estimated Hc2 values. From the magnetization measurements, it was found that irreversibility field value Hirr for the pristine sample is 7.5 T at 4 K and the same is increased to 13.5 T for 3 wt % …
Antiferromagnetic Transition In Eufe2as2: A Possible Parent Compound For Superconductors, Zhi Ren, Zengwei Zhu, Shuai Jiang, Xiangfan Xu, Qian Tao, Cao Wang, Chunmu Feng, Guanghan Cao, Zhu An Xu
Antiferromagnetic Transition In Eufe2as2: A Possible Parent Compound For Superconductors, Zhi Ren, Zengwei Zhu, Shuai Jiang, Xiangfan Xu, Qian Tao, Cao Wang, Chunmu Feng, Guanghan Cao, Zhu An Xu
Australian Institute for Innovative Materials - Papers
Ternary iron arsenide EuFe2 As2 with ThCr2 Si2 -type structure has been studied by magnetic susceptibility, resistivity, thermopower, Hall, and specific-heat measurements. The compound undergoes two magnetic phase transitions at about 200 and 20 K, respectively. The former was found to be accompanied with a slight drop in magnetic susceptibility (after subtracting the Curie-Weiss paramagnetic contribution), a rapid decrease in resistivity, a large jump in thermopower, and a sharp peak in specific heat with decreasing temperature, all of which point to a spin-density-wave-like antiferromagnetic transition. The latter was proposed to be associated with an A -type antiferromagnetic ordering of Eu2+ …
Embracing Social Uncertainties With Complex Systems Science, Pascal Perez
Embracing Social Uncertainties With Complex Systems Science, Pascal Perez
SMART Infrastructure Facility - Papers
Human ecosystems are real-life systems characterized by very strong and longterm interactions between human communities and their environment; as such they constitute an expansion of the ecological concept of ecosystem. According to Stepp and colleagues (2003), human ecosystems not only process matter and energy flows, but - and more specifically - information flows as well. Therefore, they display very specific characteristics due to our ability to communicate and learn from others, creating the conditions for co-evolutionary processes in which chance lends a hand to necessity. Bradbury (2006) argues that, until recently, human beings had been able to adapt to changes …
Diffusion And Social Networks: Revisiting Medical Innovation With Agents, Pascal Perez, N Ratna, A Dray, Q Grafton, D Newth, T Kompas
Diffusion And Social Networks: Revisiting Medical Innovation With Agents, Pascal Perez, N Ratna, A Dray, Q Grafton, D Newth, T Kompas
SMART Infrastructure Facility - Papers
the classic study on diffusion of Tetracycline by Coleman, Katz and Menzel (1966). Medical Innovation articulates how different patterns of interpersonal communications can influence the diffusion process at different stages of adoption. In their pioneering study, individual network (discussion, friendship or advice) was perceived as a set of disjointed pairs, and the extent of influences were therefore, evaluated for pairs of individuals. Given the existence of overlapping networks and consequent influences on doctors’ adoption decisions, the complexity of actual events was not captured by pair analysis. Subsequent reanalyses (Burt 1987, Strang and Tuma 1993, Valente 1995, Van den Bulte and …
Safe Water For People In Low, Small Island Pacific Nations: The Rural-Urban Dilemma, Ian White, Tony Falkland, Taboia Metutera, Mourongo Katatia, Tererei Abete-Reema, Marc Overmars, Pascal Perez, Anne Dray
Safe Water For People In Low, Small Island Pacific Nations: The Rural-Urban Dilemma, Ian White, Tony Falkland, Taboia Metutera, Mourongo Katatia, Tererei Abete-Reema, Marc Overmars, Pascal Perez, Anne Dray
SMART Infrastructure Facility - Papers
The issue of ensuring that growing communities in small island countries have access to safe water and adequate sanitation is examined in Kiribati, whose islands are spread over three million square kilometres in the central Pacific. Its coral island communities have water supply and sanitation problems among the most difficult in the world. Formulaic developed-world approaches, models, techniques and toolboxes that do not consider the social and cultural context have had little success. Changes in approach at the international, national and local levels are called for, and the resourcing of village-level water and sanitation committees would return ownership and control …
An Agent-Based Framework For Simulating Socio-Organisational Design Of Large Projects, Ricardo Peculis, Derek Rogers, Peter Campbell
An Agent-Based Framework For Simulating Socio-Organisational Design Of Large Projects, Ricardo Peculis, Derek Rogers, Peter Campbell
SMART Infrastructure Facility - Papers
The success of large projects depends on how people associated in teams and organisations perform their tasks and cooperate to achieve a shared goal. Success depends on an effective socio-organisational design that defines organisational structures; human resources in the form of people's abilities, roles and responsibilities; and establishing processes and contracts that will drive measures of success. Predicting the behaviour of large projects is difficult and the performance of the socio-organisational design is likely to be validated only when it is put in to practice. Simulation offers a way to explore the likely behaviour of social systems without the drawback …
Enhancement Of Ferroelectricity And Ferromagnetism In Rare Earth Element Doped Bifeo3, Zhenxiang Cheng, Xiaolin Wang, S X. Dou, Hideo Kimura, Kiyoshi Ozawa
Enhancement Of Ferroelectricity And Ferromagnetism In Rare Earth Element Doped Bifeo3, Zhenxiang Cheng, Xiaolin Wang, S X. Dou, Hideo Kimura, Kiyoshi Ozawa
Australian Institute for Innovative Materials - Papers
Rare earth element doped BiFeO3 thin films were fabricated using the pulsed laser deposition method and various targets made from different starting Fe2O3 and Fe3O4 iron source materials. The films fabricated using the targets made from Fe3O4 exhibit great enhancement in their ferroelectricity, due to greatly reduced electrical leakage, as well as enhanced magnetization compared to those films deposited using targets from Fe2O3. It is suggested that the Fe2+ ion plays an important role in compensating for the charge imbalance and reducing current leakage, as …
Dielectric, Magnetic, And Magnetotransport Properties In Sr Doped Two-Dimensional Re2coo4 (Re=Pr,Eu) Compounds, Qiwen Yao, Xiaolin Wang, S X. Dou
Dielectric, Magnetic, And Magnetotransport Properties In Sr Doped Two-Dimensional Re2coo4 (Re=Pr,Eu) Compounds, Qiwen Yao, Xiaolin Wang, S X. Dou
Australian Institute for Innovative Materials - Papers
In this work, we report on the studies of dielectric, magnetic, and magnetotransport properties of Sr doped RE2-xSrxCoO4 (RE=Pr or Eu, x=0.25-1.5). These compounds were systematically studied in terms of structure, magnetic, magnetotransport, and dielectric constant measurements. Rietveld refinement indicated that these compounds crystallized in K2NiF4-type structure with space group I4/mmm. Lattice parameters increase with Sr doping level. The system changes from paramagnetic to ferromagnetic with increasing Sr doping level and finally becomes ferromagnetic with TC of 230 K for Pr0.75Sr1.25CoO4 and …
A Novel Chipless Rfid System Based On Planar Multiresonators For Barcode Replacement, Stevan Preradovic, Isaac Balbin, Nemai Karmakar, Gerry Swiegers
A Novel Chipless Rfid System Based On Planar Multiresonators For Barcode Replacement, Stevan Preradovic, Isaac Balbin, Nemai Karmakar, Gerry Swiegers
Australian Institute for Innovative Materials - Papers
RFID is taking the world by storm but lowering the price of the tag is a necessity in order to completely replace barcode systems with RFID systems. Researchers around the world have been working on chipless RFID systems. In this paper we present a novel chipless RFID system for barcode replacement. The system can be effectively used in conveyor belt applications. It uses spectral signatures to encoded data and hence provide a unique ID for every tagged object. The chipless tag is fully passive and planar.
Electronic Texture Of The Thermoelectric Oxide Na0.75coo2, M -H Julien, C De Vaulx, H Mayaffre, C Berthier, M Horvatic, V Simonet, J Wooldridge, G Balakrishnan, M R. Lees, Dapeng Chen, C T. Lin, P Lejay
Electronic Texture Of The Thermoelectric Oxide Na0.75coo2, M -H Julien, C De Vaulx, H Mayaffre, C Berthier, M Horvatic, V Simonet, J Wooldridge, G Balakrishnan, M R. Lees, Dapeng Chen, C T. Lin, P Lejay
Australian Institute for Innovative Materials - Papers
From 59Co and 23Na NMR, we demonstrate the impact of the Na+ vacancy ordering on the cobalt electronic states in Na0.75CoO2: at long time scales, there is neither a disproportionation into 75 % Co3+ and 25 % Co4+ states, nor a mixed-valence metal with a uniform Co3.25+ state. Instead, the system adopts an intermediate configuration in which 30 % of the lattice sites form an ordered pattern of localized Co3+ states. Above 180 K, an anomalous mobility of specific Na+ sites is found to coexist with this electronic texture, suggesting that the formation of the latter may contribute to stabilizing …
Gel Sensors And Actuators, Paul Calvert
Gel Sensors And Actuators, Paul Calvert
Australian Institute for Innovative Materials - Papers
Gels, soft polymeric or composite materials that have a high fraction of water, are often found as structural materials and actuators in nature but have so far not found many uses when fabricated synthetically. We first examine some natural systems such as jellyfish, sea anemones, starfish, legumes, and human tissue, all having interesting ways of moving or otherwise reacting to the surrounding environment. Then we discuss swelling and cross-linking of hydrogels, followed by a look at actuation by electrically, thermally, and chemically stimulated gels, noting that electrical stimulation needs a chemical intermediary to show substantial actuation (comparable to human muscle, …
Influence Of Inductance Variation On Performance Of A Permanent Magnet Claw Pole Soft Magnetic Composite Motor, Youguang Guo, Jian Zhu, Zhi Lin, Haiyan Lu, Xiaolin Wang, Jiaxin Chen
Influence Of Inductance Variation On Performance Of A Permanent Magnet Claw Pole Soft Magnetic Composite Motor, Youguang Guo, Jian Zhu, Zhi Lin, Haiyan Lu, Xiaolin Wang, Jiaxin Chen
Australian Institute for Innovative Materials - Papers
Winding inductance is an important parameter in determining the performance of electrical machines, particularly those with large inductance variation. This paper investigates the influence of winding inductance variation on the performance of a three-phase three-stack claw pole permanent magnet motor with soft magnetic composite (SMC) stator by using an improved phase variable model. The winding inductances of the machine are computed by using a modified incremental energy method, based on three-dimensional nonlinear time-stepping magnetic field finite element analyses. The inductance computation and performance simulation are verified by the experimental results of an SMC claw pole motor prototype.
La And Nb Codoped Bifeo3 Multiferroic Thin Films On Lanio3/Si And Iro2/Si Substrates, Zhenxiang Cheng, Xiaolin Wang, Hideo Kimura, Kiyoshi Ozawa, S X. Dou
La And Nb Codoped Bifeo3 Multiferroic Thin Films On Lanio3/Si And Iro2/Si Substrates, Zhenxiang Cheng, Xiaolin Wang, Hideo Kimura, Kiyoshi Ozawa, S X. Dou
Australian Institute for Innovative Materials - Papers
Nb and La codoped BiFeO3 thin films were fabricated on oxide bottom electrodes, LaNiO3/Si and IrO2/Si, by pulsed laser deposition method. The doped BiFeO3 thin film capacitor on LaNiO3showed a remnant polarization of more than 75 µC/cm2 in a saturated hysteresis loop. The same La and Nb codoped BiFeO3 thin film capacitors on IrO2 showed a larger remnant polarization, while with a significant contribution from the leakage current. Furthermore, the doped BiFeO3 capacitor on the LaNiO3 bottom electrode showed worse fatigue resistance than the film on IrO …
Optical Property And Electronic Band Structure Of A Piezoelectric Compound Ga3po7 Studied By The First-Principles Calculation, Zhenxiang Cheng, Xiaolin Wang
Optical Property And Electronic Band Structure Of A Piezoelectric Compound Ga3po7 Studied By The First-Principles Calculation, Zhenxiang Cheng, Xiaolin Wang
Australian Institute for Innovative Materials - Papers
The structure, electronic and optical properties of a piezoelectric material, Ga3PO7 were studied by first-principles calculations in the framework of density functional theory. The calculated structure is in agreement with the experimental data. Band structure reveals that Ga3PO7 has a band gap of 3.69 eV. Analysis of partial density of states and Mulliken charge population indicates existence of GaO5 and PO4 anion groups in Ga3PO7. Furthermore, its optical properties, including dielectric constant, absorption, reflectivity, refractive index, and electron loss were calculated and analysed, which show that Ga3 …
Correlation Between Doping Induced Disorder And Superconducting Properties In Carbohydrate Doped Mgb2, Jung Ho Kim, S X. Dou, Sangjun Oh, M Jercinovic, E Babic, T Nakane, Hiroaki Kumakura
Correlation Between Doping Induced Disorder And Superconducting Properties In Carbohydrate Doped Mgb2, Jung Ho Kim, S X. Dou, Sangjun Oh, M Jercinovic, E Babic, T Nakane, Hiroaki Kumakura
Australian Institute for Innovative Materials - Papers
A comprehensive study of the effects of carbohydrate doping on the superconductivity of MgB2 has been conducted. In accordance with the dual reaction model, more carbon substitution is achieved at lower sintering temperature. As the sintering temperature is lowered, lattice disorder is increased. Disorder is an important factor determining the transition temperature for the samples studied in this work, as evidenced from the correlations among the lattice strain, the resistivity, and the transition temperature. It is further shown that the increased critical current density in the high field region can be understood by a recently-proposed percolation model [M. Eisterer …
Magnetic Anisotropy Of Naxcoo2 Single Crystals, Dapeng Chen, Xiaolin Wang, C T Lin, S X. Dou
Magnetic Anisotropy Of Naxcoo2 Single Crystals, Dapeng Chen, Xiaolin Wang, C T Lin, S X. Dou
Australian Institute for Innovative Materials - Papers
We report the magnetic properties of single crystals of NaxCoO2 (x=0.42, 0.82, and 0.87). The magnetic susceptibility measurements revealed considerable anisotropy along H parallel to ab and H parallel to c for the as-grown single crystals. It was found that an antiferromagnetic transition with a Neel temperature T-N=21 K occurred for the x=0.82 sample, and there was a paramagnetic phase for the x=0.87 sample over a wide temperature range from 2 to 300 K, but the sample with x=0.42 shows a monotonic increase of chi with increasing temperature above similar to 100 K. In addition, …