Probing second harmonic components of pH-sensitive Redox processes in a mesoporous TiO2-Nafion film electrode with Fourier-transformed large-amplitude sinusoidally modulated voltammetry

Electrochemical processes in mesoporous TiO2-Nafion thin films deposited on indium tin oxide (ITO) electrodes are inherently complex and affected by capacitance, Ohmic iR-drop, RC-time constant phenomena, and by potential and pH-dependent conductivity. In this study, large-amplitude sinusoidally modulated voltammetry (LASMV) is employed to provide access to almost purely Faradaic-based current data from second harmonic components, as well as capacitance and potential domain information from the fundamental harmonic for mesoporous TiO2-Nafion film electrodes. The LASMV response has been investigated with and without an immobilized one-electron redox system, ferrocenylmethyltrimethylammonium+. Results clearly demonstrate that the electron transfer associated with the immobilized ferrocene derivative follows two independent pathways i) electron hopping within the Nafion network and ii) conduction through the TiO2 backbone. The pH effect on the voltammetric response for the TiO2 reduction pathway (ii) can be clearly identified in the 2nd harmonic LASMV response with the diffusion controlled ferrocene response (i) acting as a pH independent reference. Application of second harmonic data derived from LASMV measurement, because of the minimal contribution from capacitance currents, may lead to reference-free pH sensing with systems like that found for ferrocene derivatives.

Peer review of teaching practice and resources : exploring new spaces to embrace cultural change

The implementation of systematic peer review as a professional development activity, and as a support for educational design activities is under-utilised in many Australian higher education institutions. This case study reports on the first stages of planning and implementation of an institution-wide project to enhance teaching and learning quality at a remote and regional university, where one of the major strategies for improvement is peer review. Through a systematic process of staff engagement in peer review, within and from outside the organisation, a substantial change in flexible learning is envisaged. A mix of new and different learning spaces are to be used in the project, including blended learning spaces for academic development. This paper describes the research framework that will guide the peer review process and examines the early findings of the design-based research. Leadership, awareness raising and development of a supportive community of inquiry are seen as key components for successful implementation of peer review. In addition, unique contextual elements add to the complexity of designing for transformative change within such a relatively new organization.

Improving public spaces for young people : the contribution of participatory research

The objectives of this chapter are to examine the contribution of public spaces to the wellbeing of young people and how participatory action research can be used as a process tool for contextually responsive, collaborative, iterative and multi-method community level practice. The addition of a spatial frame to practice can open up unexpected alliances and opportunities for enhancing the wellbeing of people.

Second harmonic generation and multiphoton microscopic detection of collagen without the need for species specific antibodies

High-resolution, high-contrast, three-dimensional images of live cell and tissue architecture can be obtained using second harmonic generation (SHG), which comprises non-absorptive frequency changes in an excitation laser line. SHG does not require any exogenous antibody or fluorophore labeling, and can generate images from unstained sections of several key endogenous biomolecules, in a wide variety of species and from different types of processed tissue. Here, we examined normal control human skin sections and human burn scar tissues using SHG on a multi-photon microscope (MPM). Examination and comparison of normal human skin and burn scar tissue demonstrated a clear arrangement of fibers in the dermis, similar to dermal collagen fiber signals. Fluorescence-staining confirmed the MPM-SHG collagen colocalization with antibody staining for dermal collagen type-I but not fibronectin or elastin. Furthermore, we were able to detect collagen MPM-SHG signal in human frozen sections as well as in unstained paraffin embedded tissue sections that were then compared with hematoxylin and eosin staining in the identical sections. This same approach was also successful in localizing collagen in porcine and ovine skin samples, and may be particularly important when species-specific antibodies may not be available. Collectively, our results demonstrate that MPM SHG-detection is a useful tool for high resolution examination of collagen architecture in both normal and wounded human, porcine and ovine dermal tissue.

Understanding the implications of digital interactions on the design of public urban spaces

This study investigated the impact of digital networked social interactions on the design of public urban spaces. Urban informatics, social media, ubiquitous computing, and mobile technology offer great potential to urban planning, as tools of communication, community engagement, and placemaking. The study considers the function of public spaces as 'third places,' that is, social places that are familiar, comfortable, social and meaningful for everyday life outside the home and work. Libraries were chosen as the study's focus. The study produced findings and insights at the intersection of urban planning (place), cultural geography and urban sociology (people), and information communication technology (technology) – the triad of urban informatics.

Food in the city : urban food movements and the (re)imagining of urban spaces

Ethical food movements are growing in number throughout Australia. Amongst these diverse movements are urban agriculture initiatives, which articulate a multitude of social and environmental values. Yet, despite the long history of production and exchange of food in urban areas, planners (and others) often overlook its significance. To assist in addressing this oversight, we take the case study of Melbourne to examine the ways in which participants in urban agriculture are re-imagining urban spaces and the future of agriculture and food systems in Australia. We demonstrate that urban food advocates' politics and practices both challenge and resist the enclosure of urban spaces. This creates new frontiers that transgress social, political, ecological and economic boundaries and edges. These transgressions or counter-enclosures articulate new visions for secure and just food systems and, in so doing, offer insights to assist planners in ensuring Australian cities support socially just and environmentally responsible food systems.

Control, operation and power sharing among parallel converter-interfaced DERs in a microgrid in the presence of unbalanced and harmonic loads

This paper demonstrates power management and control of DERs in an autonomous MG. The paper focuses on the control and performance of converter-interfaced DERs in voltage controlled mode. Several case studies are considered for a MG based on the different types of loads supplied by the MG (i.e. balanced three-phase, unbalanced, single-phase and harmonic loads). DERs are controlled by adjusting the voltage magnitude and angle in their converter output through droop control, in a decentralized concept. Based on this control method, DERs can successfully share the total demand of the MG in the presence of any type of loads. This includes proper total power sharing, unbalanced power sharing as well as harmonic power sharing, depending on the load types. The efficacy of the proposed power control, sharing and management among DERs in a microgrid is validated through extensive simulation studies using PSCAD/EMTDC.

Distribution harmonic state estimation based on a modified PSO considering parameters uncertainty

This paper presents a new algorithm based on a Modified Particle Swarm Optimization (MPSO) to estimate the harmonic state variables in a distribution networks. The proposed algorithm performs the estimation for both amplitude and phase of each injection harmonic currents by minimizing the error between the measured values from Phasor Measurement Units (PMUs) and the values computed from the estimated parameters during the estimation process. The proposed algorithm can take into account the uncertainty of the harmonic pseudo measurement and the tolerance in the line impedances of the network as well as the uncertainty of the Distributed Generators (DGs) such as Wind Turbines (WTs). The main features of the proposed MPSO algorithm are usage of a primary and secondary PSO loop and applying the mutation function. The simulation results on 34-bus IEEE radial and a 70-bus realistic radial test networks are presented. The results demonstrate that the speed and the accuracy of the proposed Distribution Harmonic State Estimation (DHSE) algorithm are very excellent compared to the algorithms such as Weight Least Square (WLS), Genetic Algorithm (GA), original PSO, and Honey Bees Mating Optimization (HBMO).

A novel algorithm based on honey bee mating optimization for distribution harmonic state estimation including distributed generators

This paper presents a new algorithm based on honey-bee mating optimization (HBMO) to estimate harmonic state variables in distribution networks including distributed generators (DGs). The proposed algorithm performs estimation for both amplitude and phase of each harmonics by minimizing the error between the measured values from phasor measurement units (PMUs) and the values computed from the estimated parameters during the estimation process. Simulation results on two distribution test system are presented to demonstrate that the speed and accuracy of proposed distribution harmonic state estimation (DHSE) algorithm is extremely effective and efficient in comparison with the conventional algorithms such as weight least square (WLS), genetic algorithm (GA) and tabu search (TS).

Distribution harmonic state estimation based on a hybrid PSO and SA algorithm considering parameters uncertainty

This paper presents a new algorithm based on a Hybrid Particle Swarm Optimization (PSO) and Simulated Annealing (SA) called PSO-SA to estimate harmonic state variables in distribution networks. The proposed algorithm performs estimation for both amplitude and phase of each harmonic currents injection by minimizing the error between the measured values from Phasor Measurement Units (PMUs) and the values computed from the estimated parameters during the estimation process. The proposed algorithm can take into account the uncertainty of the harmonic pseudo measurement and the tolerance in the line impedances of the network as well as uncertainty of the Distributed Generators (DGs) such as Wind Turbines (WT). The main feature of proposed PSO-SA algorithm is to reach quickly around the global optimum by PSO with enabling a mutation function and then to find that optimum by SA searching algorithm. Simulation results on IEEE 34 bus radial and a realistic 70-bus radial test networks are presented to demonstrate the speed and accuracy of proposed Distribution Harmonic State Estimation (DHSE) algorithm is extremely effective and efficient in comparison with the conventional algorithms such as Weight Least Square (WLS), Genetic Algorithm (GA), original PSO and Honey Bees Mating Optimization (HBMO) algorithm.

Digital Literacy and the Spaces of Academic Discourse

Digital literacy poses a particular challenge to the research-led university. Although these universities are often at the forefront of introducing digital literacy initiatives—such as e-learning platforms, technological infrastructure, and digital repositories—these applications of digital literacy tend to be more instrumental or functional than critical or creative. Certainly, this clash of cultures between the instrumental/functional and the critical/analytical is at the heart of debates over the uses of digital literacy in higher education. However, this simple equation of political forces with instrumentality and the corresponding equation of the university with a tradition of reflective thought that brings criticism to bear on instrumentality elide the fact that this conflict is more deeply rooted within the academy. This essay argues that, in fact, much of the resistance to critical uses of digital literacy comes from within the institution of the university itself. That is, the university is bound up in a scriptural economy that prioritises the printed word and that reinforces its power by way of a normative, political, and spatialised academic discourse. It is this print-based scriptural economy—in which this essay must acknowledge its own complicity—that a critical approach to digital literacy threatens to disrupt or lay bare.

Dilemmatic spaces : high-stakes testing and the possibilities of collaborative knowledge work to generate learning innovations

This paper examines collaborative researcher-practitioner knowledge work around assessment data in culturally diverse, low- socioeconomic school communities in Queensland, Australia. Specifically, the paper draws on interview accounts about the work of a bridging knowledge flows between a local university and a cluster of schools. We draw on Bernstein’s (2000) concept of recontextualisation to explore the processes of knowledge mediation in dialogues around student assessment data to design instructional innovations. We argue that critical policy studies need to explore the complex ways in which neoliberal education policies are enacted in local sites. Moreover, we suggest that an analysis of collaborative knowledge work designed to improve student learning outcomes in low-socioeconomic school communities necessitates attention to the principles regulating knowledge flows across boundaries. In addition, it necessitates attention to the ways in which mediators navigate dilemmatic spaces, anxieties and affects/feelings in order to generate innovative learning designs in the current global context of high-stakes national testing and accountability regimes.

Investigating subspace distances in semantic spaces

Semantic space models of word meaning derived from co-occurrence statistics within a corpus of documents, such as the Hyperspace Analogous to Language (HAL) model, have been proposed in the past. While word similarity can be computed using these models, it is not clear how semantic spaces derived from different sets of documents can be compared. In this paper, we focus on this problem, and we revisit the proposal of using semantic subspace distance measurements [1]. In particular, we outline the research questions that still need to be addressed to investigate and validate these distance measures. Then, we describe our plans for future research.

Semantic spaces : measuring the distance between different subspaces

Semantic Space models, which provide a numerical representation of words’ meaning extracted from corpus of documents, have been formalized in terms of Hermitian operators over real valued Hilbert spaces by Bruza et al. [1]. The collapse of a word into a particular meaning has been investigated applying the notion of quantum collapse of superpositional states [2]. While the semantic association between words in a Semantic Space can be computed by means of the Minkowski distance [3] or the cosine of the angle between the vector representation of each pair of words, a new procedure is needed in order to establish relations between two or more Semantic Spaces. We address the question: how can the distance between different Semantic Spaces be computed? By representing each Semantic Space as a subspace of a more general Hilbert space, the relationship between Semantic Spaces can be computed by means of the subspace distance. Such distance needs to take into account the difference in the dimensions between subspaces. The availability of a distance for comparing different Semantic Subspaces would enable to achieve a deeper understanding about the geometry of Semantic Spaces which would possibly translate into better effectiveness in Information Retrieval tasks.