Electrocatalytic oxidation of ascorbic acid using a single layer of gold nanoparticles immobilized on 1,6-hexanedithiol modified gold electrode

This paper describes the electrocatalytic oxidation of ascorbic acid (AA) in phosphate buffer solution by the immobilized citrate capped gold nanoparticles (AuNPs) on 1,6-hexanedithiol (HDT) modified Au electrode. X-ray photoelectron spectrum (XPS) of HDT suggests that it forms a monolayer on Au surface through one of the two single bondSH groups and the other single bondSH group is pointing away from the electrode surface. The free single bondSH groups of HDT were used to covalently attach colloidal AuNPs. The covalent attachment of AuNPs on HDT monolayer was confirmed from the observed characteristic carboxylate ion stretching modes of citrate attached with AuNPs in the infra-red reflection absorption spectrum (IRRAS) in addition to a higher reductive desorption charges obtained for AuNPs immobilized on HDT modified Au (Au/HDT/AuNPs) electrode in 0.1 M KOH when compared to HDT modified Au (Au/HDT) electrode. The electron transfer reaction of [Fe(CN)6]4−/3− was markedly hindered at the HDT modified Au (Au/HDT) electrode while it was restored with a peak separation of 74 mV after the immobilization of AuNPs on Au/HDT (Au/HDT/AuNPs) electrode indicating a good electronic communication between the immobilized AuNPs and the underlying bulk Au electrode through a HDT monolayer. The Cottrell slope obtained from the potential-step chronoamperometric measurements for the reduction of ferricyanide at Au/HDT/AuNPs was higher than that of bare Au electrode indicating the increased effective surface area of AuNPs modified electrode. The Au/HDT/AuNPs electrode exhibits excellent electrocatalytic activity towards the oxidation of ascorbic acid (AA) by enhancing the oxidation peak current to more than two times with a 210 mV negative shift in the oxidation potential when compared to a bare Au electrode. The standard heterogeneous electron transfer rate constant (ks) calculated for AA oxidation at Au/HDT/AuNPs electrode was 5.4 × 10−3 cm s−1. The oxidation peak of AA at Au/HDT/AuNPs electrode was highly stable upon repeated potential cycling. Linear calibration plot was obtained for AA over the concentration range of 1–110 μM with a correlation coefficient of 0.9950. The detection limit of AA was found to be 1 μM. The common physiological interferents such as glucose, oxalate ions and urea do not show any interference within the detection limit of AA. The selectivity of the AuNPs modified electrode was illustrated by the determination of AA in the presence of uric acid.

Suicide, statistics and the coroner: A comparative study of death investigations

Australia has a significantly higher suicide rate than England. Rather than accepting that this ‘statistical fact’ is a direct reflection of some positivist truth, this paper begins with the premise that how suicide is counted depends upon what counts as suicide. This study involves semi-structured interviews with coroners both in Australia and England, as well as observations at inquests. Important differences between the two coronial systems include: first, quite different logics of operation; second, the burden of proof for reaching a finding of suicide is significantly higher in England; and third, the presence of family members at English inquests results in far greater pressure being brought to bear upon coroners. These combined factors result in a reduced likelihood of English coroners reaching a finding of suicide. The conclusions are twofold. First, this research supports existing criticisms of comparative suicide statistics. Second, this research adds theoretical weight to criticisms of positivist analyses of social phenomena.

A collaborative rapid persona-building workshop : creating design personas with health researchers

In the HealthMap project for People With HIV, (PWHIV) designers employed a collaborative rapid ‘persona-building' workshop with health researchers to develop patient personas that embodied patient-centred design goals and contextual awareness from a variety of qualitative and quantitative data. On reflection, this collaborative rapid workshop was a process for drawing together the divergent user research insights and expertise of stakeholders into focus for a chronic disease self-management design. This paper discusses, (i) an analysis of the transcript of the workshop and, (ii) interviews with five practising senior designers, in order to reflect on how the persona-building process was enacted and its role in the HealthMap design evolution. The collaborative rapid persona-building methodology supported: embedding user research insights, eliciting domain expertise, introducing design thinking, facilitating stakeholder collaboration and defining early design requirements. The contribution of this paper is to model the process of collaborative rapid persona-building and to introduce the collaborative rapid persona-building framework as a method to generate design priorities from domain expertise and user research data.

Investigations on road noise level spatial variability within a specially designed acoustic balcony

An investigation into the spatial distribution of road traffic noise levels on a balcony is conducted. A balcony constructed to a special acoustic design due to its elevation above an 8 lane motorway is selected for detailed measurements. The as-constructed balcony design includes solid parapets, side walls, ceiling shields and highly absorptive material placed on the ceiling. Road traffic noise measurements are conducted spatially using a five channel acoustic analyzer, where four microphones are located at various positions within the balcony space and one microphone placed outside the parapet at a reference position. Spatial distributions in both vertical and horizontal planes are measured. A theoretical model and prediction configuration is presented that assesses the acoustic performance of the balcony under existing traffic flow conditions. The prediction model implements a combined direct path, specular reflection path and diffuse reflection path utilizing image source and radiosity techniques. Results obtained from the prediction model are presented and compared to the measurement results. The predictions are found to correlate well with measurements with some minor differences that are explained. It is determined that the prediction methodology is acceptable to assess a wider range of street and balcony configuration scenarios.

Introduction : studying Indonesian media worlds at the intersections of area and cultural studies

When preparing this special issue,1 our discussions with the editorial board of the International Journal of Cultural Studies (IJCS) included a moment of simultaneous surprise and reflection, which we would like to use as a starting point for our introduction to the articles appearing here. This occurred during communications about the number and length of the articles required for a special issue. The board’s representative stipulated that a specific number of articles were to be written by Indonesian scholars. The request surprised us. We had neither discussed nor anticipated ethnic or national quotas for authorial participation. But although the request caught us off guard it also stimulated us to think about the two disciplinary terrains traversed in the articles to follow.

Imaging intracellular protein dynamics by spinning disk confocal microscopy

The palette of fluorescent proteins (FPs) has grown exponentially over the past decade, and as a result, live imaging of cells expressing fluorescently tagged proteins is becoming more and more mainstream. Spinning disk confocal (SDC) microscopy is a high-speed optical sectioning technique and a method of choice to observe and analyze intracellular FP dynamics at high spatial and temporal resolution. In an SDC system, a rapidly rotating pinhole disk generates thousands of points of light that scan the specimen simultaneously, which allows direct capture of the confocal image with low-noise scientific grade-cooled charge-coupled device cameras, and can achieve frame rates of up to 1000 frames per second. In this chapter, we describe important components of a state-of-the-art spinning disk system optimized for live cell microscopy and provide a rationale for specific design choices. We also give guidelines of how other imaging techniques such as total internal reflection microscopy or spatially controlled photoactivation can be coupled with SDC imaging and provide a short protocol on how to generate cell lines stably expressing fluorescently tagged proteins by lentivirus-mediated transduction.

A time for everything : reviewing an institution’s virtual learning environment

This paper outlines a review carried out at Queensland University of Technology (QUT) in 2013 to identify the extent to which the centrally supported virtual learning environment met current and future learning and teaching needs. A range of consultation and investigation activities occurred from May to November to encourage open stakeholder feedback as well as to allow for reflection on alternative digital technologies, systems and strategies. This resulted in the development of nine recommendations, which, following a planning phase, will commence being implemented from mid-2014.

The many meanings of live coding

The ten-year anniversary of TOPLAP presents a unique opportunity for reflection and introspection. In this essay we ask the question, what is the meaning of live coding? Our goal is not to answer this question, in absolute terms, but rather to attempt to unpack some of live coding's many meanings. Our hope is that by exploring some of the formal, embodied, and cultural meanings surrounding live-coding practice, we may help to stimulate a conversation that will resonate within the live-coding community for the next ten years

Implementing ICT in Schools in a Developing Country : A Fijian Experience

Significant advances have been made towards the United Nations Millennium Development Goals on universal education. While there has been an increase in the number of children who now attend primary school, the quality of education remains an issue in many countries. Knowledge and the ability to use ICT are considered to be mandatory for citizens of this century. Information and Communication Technology (ICT) is becoming increasingly more common in classrooms in developed countries. However, ICT use is often beyond the reach of many school communities in developing countries. While supporting these developing countries through donations of technology is a start, there is an equal if not a greater need to build teacher capacity so that the resources are effective in classrooms. The Share, Engage and Educate (SEE) project is about creating educational opportunities for learners in developing countries using ICT. Through the efforts of volunteers, the project provides technological resources to schools and engages teachers in activities that develop their capacity. The SEE project has adopted a four-phase model for ICT integration: objectives, implementation, feedback, and reflection. This chapter reports upon the project’s ongoing implementation phase in Fiji, including the approach taken to build teacher capacity and the identification of factors which have impacted upon the project’s success.

The use of multimodal technologies to enhance reflective writing in teacher education

For preservice teachers new to the teaching profession, reflective practice can be a difficult process. Yet reflective writing, once mastered, has the capacity to support preservice teachers to make connections between teaching theory and professional practice, and to start to take control of their own professional learning journey. The reflective practice described in this chapter was scaffolded through a framework for writing, the use of annotated work samples and explicit teaching. This approach was enhanced through multimodal resources including written peer assessment, audio teacher feedback and a video recording of the class presentation. The video footage assisted the preservice teachers to reconcile the feedback that they received from multiple sources. This chapter describes and analyses the implementation of the PRT Pattern (Prompting Reflection using Technology). Results of this practice revealed that the multiple forms of feedback assisted the preservice teachers to analyse their performance in terms of their developing professional identity and practice.