Thales Australia

Garden Island, Australia

Thales Australia

Garden Island, Australia
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Walker J.,University of New South Wales | Budic B.,Slovenian National Institute of Chemistry | Bryant P.,Thales Australia | Kurusingal V.,Jozef Stefan Institute | And 4 more authors.
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control | Year: 2015

The route to phase-pure BiFeO3 (BFO) ceramics with excellent ferroelectric and electromechanical properties is severely impeded by difficulties associated with the perovskite phase stability during synthesis. This has meant that dopants and solid solutions with BFO have been investigated as a means of not only improving the functional properties, but also of improving the perovskite phase formation of BFO-based ceramics. The present work focuses on Sm-modified BFO ceramics of composition Bi0.88Sm0.12FeO3. The polarization and strain behaviors were investigated as a function of the phase composition, microstructure, and chemical composition. Addition of Sm reduces the susceptibility of the BFO perovskite to phase degradation by Si impurities. Si was observed to react into Sm-rich grains dispersed within the microstructure, with no large increases in the amount of bismuth-parasitic phases, namely Bi25FeO39 and Bi2Fe4O9. These as-prepared ceramics exhibited robust polarization behavior showing maximum remnant polarizations of ∼40 to 50 μC/cm2. The electric-fieldinduced strain showed an appreciable stability in terms of the driving field frequency with maximum peak-to-peak strains of ∼0.3% and a coercive field of ∼130 kV/cm. © 1986-2012 IEEE.

Walker J.,University of New South Wales | Walker J.,Jozef Stefan Institute | Bryant P.,Thales Australia | Kurusingal V.,Thales Australia | And 6 more authors.
Acta Materialia | Year: 2015

Solid-state (non-activated) and mechanochemical activation (activated) synthesis methods were used to produce Sm-modified BiFeO3 ceramics of composition Bi0.88Sm0.12FeO3. The first part shows that the formation of Bi0.88Sm0.12FeO3 using the two synthesis methods followed a different reaction pathway on annealing the powders. The non-activated ceramics reacted by forming two intermediate phases, isostructural to BiFeO3 and SmFeO3, and then inter-diffusing, forming the final Bi0.88Sm0.12FeO3 solid solution. Unlike the non-activated samples, the activated ceramic powders formed Bi0.88Sm0.12FeO3 phase on annealing the powders, without apparent intermediate phases. As revealed by transmission electron microscopy, the non-activated reaction pathway caused the Pbam phase to form as chemical inhomogeneous (Sm-rich) isolated nano-sized grain inclusions in the final ceramics. Conversely, the activated reaction pathway caused the Pbam phase to form chemically homogeneous nano-regions within the R3c phase grains. The results demonstrate the important role of processing in the appearance of the frequently discussed anti-polar Pbam phase in this system. In the second part, the high electric-field-induced polarization and strain behaviors of these ceramics were studied by means of polarization-electric (P-E) and strain-electric field (S-E) hysteresis loops, and the S-E loops were compared with those of unmodified BiFeO3. Bipolar S-E loops of Bi0.88Sm0.12FeO3 had a distinctive butterfly shape with less frequency dependence relative to BiFeO3 at driving-field frequencies of 0.1-100 Hz. BiFeO3 ceramics exhibite strong driving electric-field-frequency-dependent domain switching, the origins of which were previously attributed to a domain-wall pinning mechanism and "hardening" behavior. This study shows that Sm-modification induces a "hardening-softening" transition in BiFeO3 ceramics. © 2014 Acta Materialia Inc.

Glavan C.,Thales Australia | Palaneeswaran E.,SwinburneUniversity of Technology
Chemical Engineering Transactions | Year: 2012

The high cost of major hazard facility (MHF) accidents, in terms of loss of lives, serious injuries, loss of production and associated cost of reputation and legal costs, require major hazard facilities to operate in a regulated regime designed to control major accidents. The Australian goal-setting regulatory regime is characterised by fragmentation in terms of jurisdiction, administration, reporting of near misses and classification of MHFs. Implementation of MHF regulation falls to the control of State and Federal jurisdictions, leading to some inconsistency in interpretations, as well as the additional complexity of process and high cost of developing Safety Case documentation. Specifically, this expansive rework on compliance activities impacts on all national/international concerns that have operations in multiple states and thereby consequential exposureto higher expenses and competitive disadvantages. The discussions in this paper include: a basic comparison of MHF regulatory framework applied in different Australian jurisdictions and the impact of proposed harmonisation of Australian OHS legislation on reducing the risk of major accidents at MHFs. Copyright © 2012, AIDIC Servizi S.r.l.

Cain T.,Thales Australia | Baker P.,Thales Australia
RINA, Royal Institution of Naval Architects - International Maritime Conference 2012, Pacific 2012 | Year: 2012

The 2009 Defence White Paper defined Acoustic Technologies and Systems as a Priority Industry Capability (PIC). A PIC is a capability that confers an essential strategic advantage by being resident in Australia and, if not available, would significantly undermine defence self-reliance and ADF operational capability. A key element of the Acoustic Technologies and Systems PIC is the design and manufacture of piezoelectric ceramic sensor components that are at the heart of underwater acoustic systems. Whereas the inboard processing and display technologies required for sonar system implementation have become commoditised and are generally widely available in industry, the acoustic sensor technologies remain a niche capability that is frequently coveted and protected by those leading nations who hold this capability advantage. Fortunately, Australia is one of the nations with an indigenous acoustic sensor design and manufacturing capability. This provides the ADF with assured access to the latest and best sensor technologies, to support in-country product development to achieve the performance necessary for the RAN's sonar operating requirements and environmental conditions. In the face of emerging regional powers seeking to access strategic capabilities and driving the need to support an increased ASW effort, it is important now more than ever to safeguard and grow Australia's strategic advantage conferred by this indigenous acoustic technology and systems capability. In this paper we outline the technologies and processes involved in the design and manufacture of acoustic sensors and identify key actions required to nurture this PIC for the continued self-reliance of the ADF operational capability.

Shar R.,Thales Australia | Axon P.,Thales Australia
Proceedings - 2010 12th International Conference on Electromagnetics in Advanced Applications, ICEAA'10 | Year: 2010

The scheme of mono-pulse direction finding is well established. This paper uses a method of electromagnetic simulation to evaluate the direction finding performance of a number of common mono-pulse schemes. The mono-pulse variants include amplitude comparison of mechanically squinted beams, electronic squint and a linear interferometer. The advantage of simulation is that performance and other features of each scheme can be evaluated prior to implementation. The electromagnetic simulation is based on readily available Method of Moment (MOM) code with additional post processing. This work is applicable to situations that require emitter direction information such as cognitive radio systems, smart commumcation networks and electronic warfare. ©2010 IEEE.

Gardi A.,RMIT University | Ramasamy S.,RMIT University | Sabatini R.,RMIT University | Kistan T.,THALES Australia
2016 International Conference on Unmanned Aircraft Systems, ICUAS 2016 | Year: 2016

In this paper, the system requirements for the integration of Remotely Piloted Aircraft Systems (RPAS) in controlled airspace regions are discussed. The specificities in terms of Air Traffic Management (ATM) level of service, jurisdiction for deconfliction duties and prevalent traffic characteristics are analysed to support the identification of operational and equipage requirements for RPAS developers. Communication, Navigation, Surveillance, ATM and Avionics (CNS+A) equipment play an essential role in airspace regions characterised by high levels of Air Traffic Services (ATS) and a higher probability of traffic conflicts. A denser route structure and a more frequent occurrence of traffic conflicts mandate high CNS performance, as the deconfliction by ATM crucially relies on accurate and reliable CNS information. Notwithstanding, the reduced jurisdiction of aircraft in deconfliction duties also offers an opportunity to RPAS developers, as it relieves the requirements for on-board expert processing. © 2016 IEEE.

Triani G.,Australian Nuclear Science and Technology Organization | Bryant P.,Thales Australia
Journal of the Australian Ceramic Society | Year: 2014

This review paper will address the Australian history of electronic ceramic materials which were used primarily for their dielectric properties rather than their insulation properties. The history of these materials can be broken down into three main periods. The first period is that prior to 1950, when the electronic components industry was first set-up. The second period from approximately 1950 to 1975 involves the expansion and decline of the capacitor product lines and production capacity under the Ducon Condenser Company. The third period from approximately 1975 and continuing to the current day, involves the manufacture of piezoelectric components and devices through Ausonics Pty Ltd and a group at Plessey Ducon, which was subsequently managed in turn by its successors, Plessey Australia, GEC Marconi, Thomson Marconi and the Thales Australia companies. © 2014, Australasian Ceramic Society. All rights reserved.

Shar R.,Thales Australia
2013 International Conference on Radar - Beyond Orthodoxy: New Paradigms in Radar, RADAR 2013 | Year: 2013

This paper describes simulation results of rotating radar antenna structures next to a direction finding antenna array. The direction finding array performance is assessed using electromagnetic simulation. The method of Direction of Arrival (DOA) estimation used is mono-pulse Amplitude Comparison. © 2013 IEEE.

Gao Y.,Thales Australia
OCEANS 2013 MTS/IEEE Bergen: The Challenges of the Northern Dimension | Year: 2013

An optimal design of preamplifiers is proposed for broadband (BB) passive sonars, in which the frequency response function (FRF) of a preamplifier is optimized to maximize the output signal-to-noise ratio (SNR) of BB passive processing. The optimal design depends on passive source signals, background noise and array shapes. It contrasts with the conventional design where preamplifiers are used for whitening or conditioning hydrophone signals due to historical reasons. A hull-mounted 2-D virtual array is used as an example to show the advantage of the proposed optimal design. © 2013 IEEE.

Gao Y.,Thales Australia
OCEANS 2013 MTS/IEEE Bergen: The Challenges of the Northern Dimension | Year: 2013

In this paper power cepstra measured in shallow waters are derived theoretically to show how a sound source propagating via different paths interferes. From the derivation several useful properties of the power ceptra are revealed, which could be used to classify rahmonic tracks generated by different paths and mechanisms. Sea trial data measured in a shallow water bay are analyzed to verify the properties of the power cepstra. © 2013 IEEE.

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