Nuclear instruments and methods in physics research section B : beam interactions with materials and atoms

The impact-induced deposition of Al13 clusters with icosahedral structure on Ni(0 0 1) surface was studied by molecular dynamics (MD) simulation using Finnis–Sinclair potentials. The incident kinetic energy (Ein) ranged from 0.01 to 30 eV per atom. The structural and dynamical properties of Al clusters on Ni surfaces were found to be strongly dependent on the impact energy. At much lower energy, the Al cluster deposited on the surface as a bulk molecule. However, the original icosahedral structure was transformed to the fcc-like one due to the interaction and the structure mismatch between the Al cluster and Ni surface. With increasing the impinging energy, the cluster was deformed severely when it contacted the substrate, and then broken up due to dense collision cascade. The cluster atoms spread on the surface at last. When the impact energy was higher than 11 eV, the defects, such as Al substitutions and Ni ejections, were observed. The simulation indicated that there exists an optimum energy range, which is suitable for Al epitaxial growth in layer by layer. In addition, at higher impinging energy, the atomic exchange between Al and Ni atoms will be favourable to surface alloying.

Wide area control through aggregation of power systems

This thesis was a step forward in improving the stability of power systems by applying new control and modelling techniques. The developed methods use the data obtained from voltage angle measurement devices which are synchronized with GPS signals to stabilize the system and avoid system-wide blackouts in the event of severe faults. New approaches were developed in this research for identifying and estimating reduced dynamic system models using phasor measurement units. The main goal of this research is achieved by integrating the developed methods to obtain a feasible wide-area control system for stabilizing the power systems.

Effect of pulsed power on particle matter in diesel engine exhaust using a DBD plasma reactor

Nonthermal plasma (NTP) treatment of exhaust gas is a promising technology for both nitrogen oxides (NOX) and particulate matter (PM) reduction by introducing plasma into the exhaust gases. This paper considers the effect of NTP on PM mass reduction, PM size distribution, and PM removal efficiency. The experiments are performed on real exhaust gases from a diesel engine. The NTP is generated by applying high-voltage pulses using a pulsed power supply across a dielectric barrier discharge (DBD) reactor. The effects of the applied high-voltage pulses up to 19.44 kVpp with repetition rate of 10 kHz are investigated. In this paper, it is shown that the PM removal and PM size distribution need to be considered both together, as it is possible to achieve high PM removal efficiency with undesirable increase in the number of small particles. Regarding these two important factors, in this paper, 17 kVpp voltage level is determined to be an optimum point for the given configuration. Moreover, particles deposition on the surface of the DBD reactor is found to be a significant phenomenon, which should be considered in all plasma PM removal tests.

A design led innovation approach to gathering deep customer insights in the aviation industry

Research has long documented the value that design brings to the innovation of products and services. The research landscape has transformed in the last decade and now reflects the value of design as a different way thinking that can be applied to the innovation of business models and catalyst for strategic growth. This paper presents a case study of gathering deep customer insights through a design led innovation approach and reveals industry perspectives and attitudes towards the value of deep customer insights within the context of a leading Australian airport corporation. The findings highlight that the process of gathering deep customer insights encourages a design led approach to testing assumptions and developing stronger customer engagement. The richness of the deep customer insights also provided a bridge to future thought by provoking possible product, service and business innovations which aligned to the airport corporation’s vision. The implications of the study reveal how quantitative market data, which reveals broad sociocultural trends into ‘how’ and ‘what’ customers interact with within an airport, can be strongly validated and built upon through qualitative deep customer insights that explore ‘why’ those choices to interact are made. Future research is then presented which aims to widely disseminate a design led approach to innovation within internal stakeholders of the airport corporation through the development of a digital strategy.

Harnessing the power of real and virtual social networks during disasters

The mass media and emergency services organisations routinely gather information and disseminate it to the public. During disaster situations both the media and emergency services require acute situational awareness. New social media technologies offer opportunities to enhance situational awareness by crowd-sourcing information using real and virtual social networks. This paper documents how real and virtual social networks were used by a reporter and by members of the public to gather and disseminate emergency information during the flash flood disaster in Toowoomba and the Lockyer Valley in January 2011 and in the days and weeks after the disaster.

Improving power quality in low-voltage networks containing distributed energy resources

Severe power quality problems can arise when a large number of single-phase distributed energy resources (DERs) are connected to a low-voltage power distribution system. Due to the random location and size of DERs, it may so happen that a particular phase generates excess power than its load demand. In such an event, the excess power will be fed back to the distribution substation and will eventually find its way to the transmission network, causing undesirable voltage-current unbalance. As a solution to this problem, the article proposes the use of a distribution static compensator (DSTATCOM), which regulates voltage at the point of common coupling (PCC), thereby ensuring balanced current flow from and to the distribution substation. Additionally, this device can also support the distribution network in the absence of the utility connection, making the distribution system work as a microgrid. The proposals are validated through extensive digital computer simulation studies using PSCADTM

Universal active and reactive power control of electronically interfaced distributed generation sources in virtual power plants operating in gridconnected and islanding modes

The control paradigms of the distributed generation (DG) sources in the smart grid are realised by either utilising virtual power plant (VPP) or by employing MicroGrid structures. Both VPP and MicroGrid are presented with the problem of control of power flow between their comprising DG sources. This study depicts this issue for VPP and proposes a novel and improved universal active and reactive power flow controllers for three-phase pulse width modulated voltage source inverters (PWM-VSI) operating in the VPP environment. The proposed controller takes into account all cases of R-X relationship, thus allowing it to function in systems operating at high, medium (MV) and low-voltage (LV) levels. Also proposed control scheme for the first time in an inverter control takes into account the capacitance of the transmission line which is an important factor to accurately represent medium length transmission lines. This allows the proposed control scheme to be applied in VPP structures, where DG sources can operate at MV LV levels over a short/medium length transmission line. The authors also conducted small signal stability analysis of the proposed controller and compared it against the small signal study of the existing controllers.

ASICS : authenticated key exchange security incorporating certification systems

Most security models for authenticated key exchange (AKE) do not explicitly model the associated certification system, which includes the certification authority (CA) and its behaviour. However, there are several well-known and realistic attacks on AKE protocols which exploit various forms of malicious key registration and which therefore lie outside the scope of these models. We provide the first systematic analysis of AKE security incorporating certification systems (ASICS). We define a family of security models that, in addition to allowing different sets of standard AKE adversary queries, also permit the adversary to register arbitrary bitstrings as keys. For this model family we prove generic results that enable the design and verification of protocols that achieve security even if some keys have been produced maliciously. Our approach is applicable to a wide range of models and protocols; as a concrete illustration of its power, we apply it to the CMQV protocol in the natural strengthening of the eCK model to the ASICS setting.

A three-dimensional analysis of power and engaged scholarship

This dissertation investigates the nature of power in university-industry linkages and how such power affects the process of knowledge production in engaged scholarship. The most critical finding of this dissertation is that the theory of engaged scholarship fails to account for the socialised beliefs regarding the superior value of academic knowledge, which governs the behaviour and perceptions of academics and industry partners within university-industry linkages. The dissertation is supported by data sourced from interviews with 48 academic and industry partners’ project leaders from 24 large scale research projects and thematic analysis guided by Steven Lukes’ (1974) radical framework of power.

The role of customer gratitude in strengthening seller-buyer relationships

Despite its emphasis on relationships between buyers and sellers, and the effect of emotion on behaviours, marketing literature has not yet investigated customer gratitude as an element of relational exchange. Gratitude is a significant component of personal relationships and may offer important insights into how perceptions of relationship marketing investments impact customer trust in, satisfaction with and affective commitment to a seller. In addition, customer gratitude may provide a more complete explanation of how marketing investments work. Consequently, this research contributes to marketing literature by investigating customer gratitude as a mediating mechanism in the relationship between customer perceptions of relationship marketing investments and customer trust in, satisfaction with and affective commitment to the seller: all dimensions of relationship quality.

Assisted suicide where the "assistor" is a beneficiary under the deceased's will and/or attorney under a power of attorney granted by the deceased : what are the potential consequences?

The recent criminal conviction 1 of Queensland teacher, Merin Nielsen, for aiding the suicide of an elderly acquaintance, Frank Ward, raises some timely issues, particularly for succession lawyers. This is the second time in recent years that there has been a conviction of a person who participated in a scheme

Power converters design and analysis for high power piezoelectric ultrasonic transducers

High power piezoelectric ultrasonic transducers have been widely exploited in a variety of applications. The critical behaviour of a piezoelectric device is encapsulated in its resonant frequencies because of its maximum transmission performance at these frequencies. Therefore power electronic converters should be tuned at those resonant frequencies to transfer electrical power to mechanical power efficiently. However, structural and environmental changes cause variations in the device resonant frequencies which can degrade the system performance. Hence, estimating the device resonant frequencies within the incorporated setup can significantly improve the system performance. This paper proposes an efficient resonant frequency estimation approach to maintain the performance of high power ultrasonic applications using the employed power converter. Experimental validations indicate the effectiveness of the proposed method.

Brothers in arms – An experiment on the alliance puzzle

The generic alliance game considers players in an alliance who fight against an external enemy. After victory, the alliance may break up, and its members may fight against each other over the spoils of the victory. Our experimental analysis of this game shows: In-group solidarity vanishes after the break-up of the alliance. Former ‘brothers in arms’ fight even more vigorously against each other than strangers do. Furthermore, this vigorous internal fighting is anticipated and reduces the ability of the alliance to mobilize the joint fighting effort, compared to a situation in which victorious alliance members share the spoils of victory equally and peacefully