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Full-Text Articles in Physical Sciences and Mathematics

Privacy Issues And Solutions In Social Network Sites, Xi Chen, Katina Michael Dec 2012

Privacy Issues And Solutions In Social Network Sites, Xi Chen, Katina Michael

Associate Professor Katina Michael

The boom of the internet and the explosion of new technologies have brought with them new challenges and thus new connotations of privacy. Clearly, when people deal with e-government and e-business, they do not only need the right to be let alone, but also to be let in secret. Not only do they need freedom of movement, but also to be assured of the secrecy of their information. Solove [6] has critiqued traditional definitions of privacy and argued that they do not address privacy issues created by new online technologies. Austin [7] also asserts: “[w]e do need to sharpen and …


Indian Millennials: Are Microchip Implants A More Secure Technology For Identification And Access Control?, Christine Perakslis, Katina Michael Oct 2012

Indian Millennials: Are Microchip Implants A More Secure Technology For Identification And Access Control?, Christine Perakslis, Katina Michael

Associate Professor Katina Michael

This mixed methods study with a sequential explanatory strategy explored qualitatively the statistically significant quantitative findings relative to Indian respondents’ perceptions about RFID (radio frequency identification) transponders implanted into the human body. In the first analysis phase of the study, there was a significant chi-square analysis reported (χ2 = 56.64, df = 3, p = .000) relative to the perception of small business owners (N = 453) that implanted chips are a more secure form of identification and/or access control in organizations and the respondents’ country of residence. Countries under study included Australia, India, the UK and US. The country …


The Value Of Government Mandated Location-Based Services In Emergencies In Australia, Anas Aloudat, Katina Michael, Roba Abbas, Mutaz Al-Debei Jul 2012

The Value Of Government Mandated Location-Based Services In Emergencies In Australia, Anas Aloudat, Katina Michael, Roba Abbas, Mutaz Al-Debei

Associate Professor Katina Michael

The adoption of mobile technologies for emergency management has the capacity to save lives. In Australia in February 2009, the Victorian Bushfires claimed 173 lives, the worst peace-time disaster in the nation’s history. The Australian government responded swiftly to the tragedy by going to tender for mobile applications that could be used during emergencies, such as mobile alerts and location services. These applications, which are becoming increasingly accurate with the evolution of positioning techniques, have the ability to deliver personalized information direct to the citizen during crises, complementing traditional broadcasting mediums like television and radio. Indeed governments have a responsibility …


Commentary On: Mann, Steve (2012): Wearable Computing, Katina Michael, M.G. Michael Apr 2012

Commentary On: Mann, Steve (2012): Wearable Computing, Katina Michael, M.G. Michael

Associate Professor Katina Michael

In Professor Steve Mann- inventor, physicist, engineer, mathematician, scientist, designer, developer, project director, filmmaker, artist, instrumentalist, author, photographer, actor, activist- we see so much of the paradigmatic classical Greek philosopher. I recall asking Steve if technology shaped society or society shaped technology. He replied along the lines that the question was superfluous. Steve instead pointed to praxis, from which all theory, lessons or skills stem, are practiced, embodied and realized. Steve has always been preoccupied by the application of his ideas into form. In this way too, he can be considered a modern day Leonardo Da Vinci.


Book Review: Securing The Cloud: Cloud Computer Security Techniques And Tactics, Katina Michael Apr 2012

Book Review: Securing The Cloud: Cloud Computer Security Techniques And Tactics, Katina Michael

Associate Professor Katina Michael

With so much buzz around Cloud Computing, books like this one written by Winkler are much in demand. Winkler’s experience in the computing business shines through and as readers we are spoiled with a great deal of useful strategic information- a jam packed almost 300 page volume on securing the cloud.


In Memoriam: Associate Professor Dr Elaine Lawrence, Katina Michael Apr 2012

In Memoriam: Associate Professor Dr Elaine Lawrence, Katina Michael

Associate Professor Katina Michael

Despite being a graduate of the rigorous Bachelor of Information Technology at the University of Technology, Sydney (UTS) in 1996, I was unfortunate in that I missed being taught by Associate Professor Elaine Lawrence who began working at UTS in 1990 as a Lecturer in Computing Science. Dr Lawrence became a senior lecturer in 2000, and subsequently an associate professor in 2006. Our paths crossed in 2002 when I was tasked to deliver a new course entitled “eBusiness Principles” in my first year of lecturing at the University of Wollongong, and after an initial scurry to find an adequate textbook, …


Sousveillance And The Social Implications Of Point Of View Technologies In The Law Enforcement Sector, Katina Michael, M.G. Michael Feb 2012

Sousveillance And The Social Implications Of Point Of View Technologies In The Law Enforcement Sector, Katina Michael, M.G. Michael

Associate Professor Katina Michael

Policing today has become a high-tech affair; especially in the provision of incident event tracking and reporting systems increasingly being used to provide evidence in a court of law. These in-car video (ICV) and body worn recording systems are said to increase convictions and eliminate false claims made by defendants, providing documentary support to police officers and their associated actions in an incident. But today, new technologies such as smart phones equipped with cameras and global positioning system chipsets can also be found in the hands of the everyday citizen, used to capture everyday happenings and distributed to social networks …


Book Review: Security Risk Management: Building An Information Security Risk Management Program From The Ground Up, Katina Michael Jan 2012

Book Review: Security Risk Management: Building An Information Security Risk Management Program From The Ground Up, Katina Michael

Associate Professor Katina Michael

In an age of outsourcing tasks that are not considered to be a core competency of the business, organisations have often relied on external consultants for matters pertaining to security. In actual fact, most companies could have utilized existing skill-sets in-house to produce a security risk management program, if only they knew what steps to take, and how to go about it all. Evan Wheeler in his book on information security risk management does just that- he equips professionals tasked with security, with the thinking required to create a program that is more preoccupied with the complex strategic-level questions than …


Location Privacy Under Dire Threat As Uberveillance Stalks The Streets, Katina Michael, Roger Clarke Jan 2012

Location Privacy Under Dire Threat As Uberveillance Stalks The Streets, Katina Michael, Roger Clarke

Associate Professor Katina Michael

Location tracking and monitoring applications have proliferated with the arrival of smart phones that are equipped with onboard global positioning system (GPS) chipsets. It is now possible to locate a smart phone user down to 10 metres of accuracy on average. Innovators have been quick to capitalise on this emerging market by introducing novel pedestrian tracking technologies which can denote the geographic path of a mobile user. At the same time there is contention by law enforcement personnel over the need for a warrant process to track an individual in a public space. This paper considers the future of location …


A Novel Route To Copper(Ii) Detection Using 'Click' Chemistry-Induced Aggregation Of Gold Nanoparticles, Carol Hua, William H. Zhang, Swahnnya De Almeida, Simone Ciampi, Danmar Gloria, Guozhen Liu, Jason Brian Harper, J Justin Gooding Jan 2012

A Novel Route To Copper(Ii) Detection Using 'Click' Chemistry-Induced Aggregation Of Gold Nanoparticles, Carol Hua, William H. Zhang, Swahnnya De Almeida, Simone Ciampi, Danmar Gloria, Guozhen Liu, Jason Brian Harper, J Justin Gooding

Australian Institute for Innovative Materials - Papers

A simple colorimetric method for the detection of copper ions in water is described. This method is based on the 'click' copper(i)-catalyzed azide-alkyne cycloaddition reaction and its use in promoting the aggregation of azide-tagged gold nanoparticles by a dialkyne cross-linker is described. Nanoparticle cross-linking, evidenced as a colour change, is used for the detection of copper ions. The lowest detected concentration by the naked eye was 1.8 μM, with the response linear with log(concentration) between 1.8-200 μM. The selectivity relative to other potentially interfering ions was evaluated.


Gating The Charge State Of Single Fe Dopants In The Topological Insulator Bi 2 Se 3 With A Scanning Tunneling Microscope, Canli Song, Yeping Jiang, Yi-Lin Wang, Zhi Li, Lili Wang, Ke He, Xi Chen, Xu-Cun Ma, Qi-Kun Xue Jan 2012

Gating The Charge State Of Single Fe Dopants In The Topological Insulator Bi 2 Se 3 With A Scanning Tunneling Microscope, Canli Song, Yeping Jiang, Yi-Lin Wang, Zhi Li, Lili Wang, Ke He, Xi Chen, Xu-Cun Ma, Qi-Kun Xue

Australian Institute for Innovative Materials - Papers

Low-temperature scanning tunneling microscope (STM) is exploited to study directly the atomic and electronic structures of single Fe dopants in topological insulator Bi2Se3 thin films. Fe atoms predominantly and isovalently substitute for two distinct Bi sites at the subsurface with charge neutrality. In the vicinity of Fe substitutions, circular depressions in STM topography and sharp rings in spatially resolved conductance map, whose diameters apparently depend on the tunneling conditions, are observed. We show that the phenomena correlate well with the switching between Fe3+ and Fe2+ charge states due to the gate effect of the tunneling tip, as further evidenced by …


A Battery Composed Of A Polypyrrole Cathode And A Magnesium Alloy Anode-Toward A Bioelectric Battery, Yong Kong, Caiyun Wang, Yang Yang, Chee O. Too, Gordon G. Wallace Jan 2012

A Battery Composed Of A Polypyrrole Cathode And A Magnesium Alloy Anode-Toward A Bioelectric Battery, Yong Kong, Caiyun Wang, Yang Yang, Chee O. Too, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

A bioelectric battery can be implanted into the human body and relies on oxygen in the internal body fluid to produce electrical energy. In this work, a battery that uses polypyrrole doped with a biological polyelectrolyte (dextran sulfate, an anti-coagulant) as the cathode and bioresorbable Mg alloy (AZ61) as the anode was developed. This battery exhibited a discharge capacity of 565 mA h g-1 in phosphate buffered saline (PBS, pH = 7.4), a commonly used electrolyte in biological research; offering a specific energy density of similar to 790W h kg-1. The electrochemical properties of the cathode, anode …


Anisotropic And Excellent Magnetocaloric Properties Of La 0.7ca0.3mno3 Single Crystal With Anomalous Magnetization, J.C Debnath, Rong Zeng, Jung Ho Kim, Dapeng Chen, S X. Dou Jan 2012

Anisotropic And Excellent Magnetocaloric Properties Of La 0.7ca0.3mno3 Single Crystal With Anomalous Magnetization, J.C Debnath, Rong Zeng, Jung Ho Kim, Dapeng Chen, S X. Dou

Australian Institute for Innovative Materials - Papers

Magnetic properties and the magnetocaloric effect (MCE) have been investigated in La0.7Ca0.3MnO3 single crystal with applied field along both the ab-plane and the c-direction. Due to the magnetocrystalline anisotropy, the crystal exhibits anisotropy in the MCE. Upon application of a 5 T field, the magnetic entropy changes (SM), reaching values of 7.668 J/(kg K) and 6.412 J/(kg K) for both the ab-plane and the c-direction, respectively. A magnetic entropy change of 3.3 J/(kg K) was achieved for a magnetic field change of 1.5 T at the Curie temperature, TC = 245 K. Due to the absence of grains in the …


Effect Of Frozen Spin On The Magnetocaloric Property Of La0.7ca0.3coo3 Polycrystalline And Single Crystal Samples, J C. Debnath, R Zeng, J H. Kim, P Shamba, Dapeng Chen, S X. Dou Jan 2012

Effect Of Frozen Spin On The Magnetocaloric Property Of La0.7ca0.3coo3 Polycrystalline And Single Crystal Samples, J C. Debnath, R Zeng, J H. Kim, P Shamba, Dapeng Chen, S X. Dou

Australian Institute for Innovative Materials - Papers

Polycrystalline (PC) and single crystalline (SC) samples of La0.7Ca0.3CoO3 (LCCO) with the perovskite structure were synthesized by conventional solid-state reaction and the floating-zone growth method. We conducted isothermal magnetization measurements of the PC and SC samples at temperatures from 2.8 K to 140 K, and evaluated the magnetic entropy change (−ΔSM) under zero field cooling (ZFC) and field cooling (FC) to 2.8 K. An interesting result has been obtained, where the −ΔSM–T curves in the low temperature range show totally different features between the ZFC and FC cooling procedures. The −ΔS …


Microscopic Role Of Carbon On Mgb2 Wire For Critical Current Density Comparable To Nbti, Jung Ho Kim, Sangjun Oh, Yoon-Uk Heo, Satoshi Hata, Hiroaki Kumakura, Akiyoshi Matsumoto, Masatoshi Mitsuhara, Seyong Choi, Yusuke Shimada, Minoru Maeda, Judith Macmanus-Driscoll, S X. Dou Jan 2012

Microscopic Role Of Carbon On Mgb2 Wire For Critical Current Density Comparable To Nbti, Jung Ho Kim, Sangjun Oh, Yoon-Uk Heo, Satoshi Hata, Hiroaki Kumakura, Akiyoshi Matsumoto, Masatoshi Mitsuhara, Seyong Choi, Yusuke Shimada, Minoru Maeda, Judith Macmanus-Driscoll, S X. Dou

Australian Institute for Innovative Materials - Papers

Increasing dissipation-free supercurrent has been the primary issue for practical application of superconducting wires. For magnesium diboride, MgB2, carbon is known to be the most effective dopant to enhance high-field properties. However, the critical role of carbon remains elusive, and also low-field critical current density has not been improved. Here, we have undertaken malic acid doping of MgB2 and find that the microscopic origin for the enhancement of high-field properties is due to boron vacancies and associated stacking faults, as observed by high-resolution transmission electron microscopy and electron energy loss spectroscopy. The carbon from the malic acid almost uniformly encapsulates …


Boron-Nitrogen-Hydrogen (Bnh) Compounds: Recent Developments In Hydrogen Storage, Applications In Hydrogenation And Catalysis, And New Syntheses, Zhenguo Huang, Tom Autrey Jan 2012

Boron-Nitrogen-Hydrogen (Bnh) Compounds: Recent Developments In Hydrogen Storage, Applications In Hydrogenation And Catalysis, And New Syntheses, Zhenguo Huang, Tom Autrey

Australian Institute for Innovative Materials - Papers

The strong efforts devoted to the exploration of BNH compounds for hydrogen storage have led to impressive advances in the field of boron chemistry. This review summarizes progress in this field from three aspects. It starts with the most recent developments in using BNH compounds for hydrogen storage, covering NH3BH3, B3H8- containing compounds, and CBN compounds. The following section then highlights interesting applications of BNH compounds in hydrogenation and catalysis. The last part is focused on breakthroughs in the syntheses and discovery of new BNH organic analogues. The role of N-Hδ+ …


Efficiency Of A Compact Elliptical Planar Ultra-Wideband Antenna Based On Conductive Polymers, Thomas Kaufmann, Akhilesh Verma, Van-Tan Truong, Bo Weng, Roderick Shepherd, Christopher Fumeaux Jan 2012

Efficiency Of A Compact Elliptical Planar Ultra-Wideband Antenna Based On Conductive Polymers, Thomas Kaufmann, Akhilesh Verma, Van-Tan Truong, Bo Weng, Roderick Shepherd, Christopher Fumeaux

Australian Institute for Innovative Materials - Papers

A planar antenna for ultra-wideband (UWB) applications covering the 3.1–10.6 GHz range has been designed as a test bed for efficiency measurements of antennas manufactured using polymer conductors. Two types of conductive polymers, PEDOT and PPy (polypyrrole), with very different thicknesses and conductivities have been selected as conductors for the radiating elements. A comparison between measured radiation patterns of the conductive polymers and a copper reference antenna allows to estimate the conductor losses of the two types of conductive polymers. For a 158 μm thick PPy polymer, an efficiency of almost 80% can be observed over the whole UWB spectrum. …


Temperature And Frequency Dependent Giant Magnetodielectric Coupling In Dymn0.33fe0.67o3, Fang Hong, Zhenxiang Cheng, Xiaolin Wang Jan 2012

Temperature And Frequency Dependent Giant Magnetodielectric Coupling In Dymn0.33fe0.67o3, Fang Hong, Zhenxiang Cheng, Xiaolin Wang

Australian Institute for Innovative Materials - Papers

Perovskite DyMn0.33Fe0.67O3 experiences a paramagnetism-antiferromagnetism transition at 450K and spin reorientation at 290 K. Magnetodielectric properties were studied around the spin reorientation transition. Both giant positive and giant negative magnetodielectric coupling (MDC) were observed near room temperature. The MDC shows strong temperature and frequency dependence, and the sign changes from positive to negative when magnetic state transits from a canted antiferromagnetic state to a collinear antiferromagnetic state. Possible mechanisms are proposed based on the Maxwell-Wagner model, phase transition, the magnetoresistance effect, and spin-phonon coupling.


Electrically Conductive, Tough Hydrogels With Ph Sensitivity, Sina Naficy, Joselito M. Razal, Geoffrey M. Spinks, Gordon G. Wallace, Philip G. Whitten Jan 2012

Electrically Conductive, Tough Hydrogels With Ph Sensitivity, Sina Naficy, Joselito M. Razal, Geoffrey M. Spinks, Gordon G. Wallace, Philip G. Whitten

Australian Institute for Innovative Materials - Papers

Electrically conductive, mechanically tough hydrogels based on a double network (DN) comprised of poly(ethylene glycol) methyl ether methacrylate (PPEGMA) and poly(acrylic acid) (PAA) were produced. Poly(3,4-ethylenedioxythiophene) (PEDOT) was chemically polymerized within the tough DN gel to provide electronic conductivity. The effects of pH on the tensile and compressive mechanical properties of the fully swollen hydrogels, along with their electrical conductivity and swelling ratio were determined. Compressive and tensile strengths as high as 11.6 and 0.6 MPa, respectively, were obtained for hydrogels containing PEDOT with a maximum conductivity of 4.3 S cm-1. This conductivity is the highest yet reported …


Strain Modulated Transient Photostriction In La And Nb Codoped Multiferroic Bifeo3 Thin Films, Zuanming Jin, Yue Xu, Zhengbing Zhang, Xian Lin, Guohong Ma, Zhenxiang Cheng, Xiaolin Wang Jan 2012

Strain Modulated Transient Photostriction In La And Nb Codoped Multiferroic Bifeo3 Thin Films, Zuanming Jin, Yue Xu, Zhengbing Zhang, Xian Lin, Guohong Ma, Zhenxiang Cheng, Xiaolin Wang

Australian Institute for Innovative Materials - Papers

The coherent longitudinal acoustic (LA) phonons in La and Nb codoped polycrystalline BiFeO3 (Bi0.8La0.2Fe 0.99Nb0.01O3 (BLFNO)) films are photo-induced and detected by the ultrafast reflectance spectroscopy. The generation mechanism of LA phonons is strongly connected with the ferroelectric polarization and is attributed to the transient photostriction effect, which is a combination of the optical rectification effect and the electrostriction effect. The strain modulation of sound velocity and out-of-plane elastic properties are demonstrated in BLFNO film on SrTiO3, which gives the insight on the dynamical coupling between electrical polarization and lattice deformation. Our findings are desired for the design of BiFeO3-based …


Material Characterization At Low Frequencies Using Thz And Raman Spectroscopy, Y Kutuvantavida, G V M Williams, E M. Pogson, D Bhuiyan, K Radhanpura, Roger A. Lewis Jan 2012

Material Characterization At Low Frequencies Using Thz And Raman Spectroscopy, Y Kutuvantavida, G V M Williams, E M. Pogson, D Bhuiyan, K Radhanpura, Roger A. Lewis

Australian Institute for Innovative Materials - Papers

We present results from wideband THz, low wave-number Raman, and FTIR measurements on benzoic acid and two of its derivatives. The low energy vibrational modes have been identified and compared with the results from calculations.


The Geologic Turn: Architecture's New Alliance, Etienne Turpin Jan 2012

The Geologic Turn: Architecture's New Alliance, Etienne Turpin

SMART Infrastructure Facility - Papers

Recent research and practice in the fields of architecture, art, and philosophy suggest the increasing influence of geology with the design disciplines, visual arts, and theoretical humanities. The symposium A Geologic Turn: Architecture's New Alliance, curated by Etienne Turpin, Ph.D., as part of the Sanders Research Fellowship at the Taubman College of Architecture & Urban Planning, University of Michigan, bring together researchers, scholars, and practitioners whose work is at the center of this fecund transdisciplinary trajectory. The objectives of the symposium are to encourage new productive connections among current scholarship and practice, and to expose this new transdisciplanary research to …


Waypoints On A Journey Of Discovery: Mental Models In Human Environment Interactions, Timothy Lynam, Raphael Mathevet, Michel Etienne, Samantha Stone-Jovicich, Anne Leitch, Nathalie Jones, Helen Ross, Derick Du Toit, Sharon Pollard, Harry Biggs, Pascal Perez Jan 2012

Waypoints On A Journey Of Discovery: Mental Models In Human Environment Interactions, Timothy Lynam, Raphael Mathevet, Michel Etienne, Samantha Stone-Jovicich, Anne Leitch, Nathalie Jones, Helen Ross, Derick Du Toit, Sharon Pollard, Harry Biggs, Pascal Perez

SMART Infrastructure Facility - Papers

Although the broad concept of mental models is gaining currency as a way to explore the link between how people think and interact with their world, this concept is limited by a theoretical and practical understanding of how it can be applied in the study of human-environment relationships. Tools and processes are needed to be able to elicit and analyze mental models. Because mental models are not directly observable, it is also important to understand how the application of any tools and processes affects what is measured. Equally important are the needs to be clear on the intent of the …


Actuating Individual Electrospun Hydrogel Nanofibres, Adrian Gestos, Philip G. Whitten, Gordon G. Wallace, Geoffrey Maxwell Spinks Jan 2012

Actuating Individual Electrospun Hydrogel Nanofibres, Adrian Gestos, Philip G. Whitten, Gordon G. Wallace, Geoffrey Maxwell Spinks

Australian Institute for Innovative Materials - Papers

The actuation of a single hydrogel nanofibre is measured for the first time by AFM. The actuation stress generated was comparable to that produced by skeletal muscle and the actuation rate was significantly increased by the nanoscale dimensions of the fibre.


Polypyrrole Coated Nylon Lycra Fabric As Stretchable Electrode For Supercapacitor Applications, Binbin Yue, Caiyun Wang, Xin Ding, Gordon G. Wallace Jan 2012

Polypyrrole Coated Nylon Lycra Fabric As Stretchable Electrode For Supercapacitor Applications, Binbin Yue, Caiyun Wang, Xin Ding, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Wearable electronics offer the combined advantages of both electronics and fabrics. Being an indispensable part of these electronics, lightweight, stretchable and wearable power sources are strongly demanded. Here we describe a daily-used nylon lycra fabric coated with polypyrrole as electrode for stretchable supercapacitors. Polypyrrole was synthesized on the fabric via a simple chemical polymerization process with ammonium persulfate (APS) as an oxidant and naphthalene-2,6-disulfonic acid disodium salt (Na2NDS) as a dopant. This material was characterized with FESEM, FTIR, tensile stress, and studied as a supercapacitor electrode in 1.0 M NaCl. This conductive textile could endure 1000 stretching cycles …


Enhanced Hydrogen Storage Properties Of Naalh4 Co-Catalysed With Niobium Fluoride And Single-Walled Carbon Nanotubes, Jianfeng Mao, Zaiping Guo, Hua-Kun Liu Jan 2012

Enhanced Hydrogen Storage Properties Of Naalh4 Co-Catalysed With Niobium Fluoride And Single-Walled Carbon Nanotubes, Jianfeng Mao, Zaiping Guo, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

The effects of single-walled carbon nanotubes (SWCNTs) as a co-catalyst with NbF5 on the dehydrogenation and hydrogenation kinetics of NaAlH4 were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, differential thermal analysis, temperature-programmed desorption, and isothermal hydrogen ab/desorption techniques. It has been revealed that there is a synergistic effect of SWCNTs and NbF5 on the de/rehydrogenation of NaAlH4, which improves the hydrogen de/absorption performance when compared to adding either SWCNTs or NbF5 alone. For example, the apparent activation energy for the first-step and the second-step dehydrogenation of the co-doped NaAlH4 sample is estimated to be 85.9 …


Magnetocapacitance Effect In Nonmultiferroic Yfe03 Single Crystal, Z X. Cheng, H Shen, J Xu, Peng Liu, S J. Zhang, Jianli Wang, Xiaolin Wang, S X. Dou Jan 2012

Magnetocapacitance Effect In Nonmultiferroic Yfe03 Single Crystal, Z X. Cheng, H Shen, J Xu, Peng Liu, S J. Zhang, Jianli Wang, Xiaolin Wang, S X. Dou

Australian Institute for Innovative Materials - Papers

YFeO3 single crystal displays two relaxor-like dielectric relaxations, one at low temperature (170300 K) and one at high temperature (370520 K), which are attributed to the activation of electrons and oxygen vacancies, respectively. Above the temperature at which electrons are activated, the sample displays a large magnetocapacitance effect. Comparison of the impedance Cole-Cole plots measured with and without applied magnetic field reveals that the occurrence of magnetocapacitance effect is accompanied with an increasing in DC conductivity under magnetic field after the activation of electrons, which is explained by the enhancement of electron jumping in Fe2b-O-Fe3b chains by magnetic field. Thus …


Large Scale Synthesis Of V-Shaped Rutile Twinned Nanorods, Weigang Lu, Britain Bruner, Gilberto Casillas, Jibao He, Miguel Jose-Yacaman, Patrick J. Farmer Jan 2012

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 …


Power To You: Carbon Nanotube Muscles Are Going Strong, Geoffrey M. Spinks Jan 2012

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.


Investigation Of Phase Composition And Nanoscale Microstructure Of High-Energy Ball-Milled Mgcu Sample, Zongqing Ma, Yongchang Liu, Liming Yu, Qi Cai Jan 2012

Investigation Of Phase Composition And Nanoscale Microstructure Of High-Energy Ball-Milled Mgcu Sample, Zongqing Ma, Yongchang Liu, Liming Yu, Qi Cai

Australian Institute for Innovative Materials - Papers

The ball milling technique has been successfully applied to the synthesis of various materials such as equilibrium intermetallic phases, amorphous compounds, nanocrystalline materials, or metastable crystalline phases. However, how the phase composition and nanoscale microstructure evolute during ball milling in various materials is still controversial due to the complex mechanism of ball milling, especially in the field of solid-state amorphization caused by ball milling. In the present work, the phase evolution during the high-energy ball milling process of the Mg and Cu (atomic ratio is 1:1) mixed powder was investigated. It was found that Mg firstly reacts with Cu, forming …