Indications of superconductivity in doped highly oriented pyrolytic graphite

We have observed possible superconductivity using standard resistance vs. temperature techniques in phosphorous ion implanted Highly Oriented Pyrolytic Graphite. The onset appears to be above 100 K and quenching by an applied magnetic field has been observed. The four initial boron implanted samples showed no signs of becoming superconductive whereas all four initial and eight subsequent samples that were implanted with phosphorous showed at least some sign of the existence of small amounts of the possibly superconducting phases. The observed onset temperature is dependent on both the number of electron donors present and the amount of damage done to the graphene sub-layers in the Highly Oriented Pyrolytic Graphite samples. As a result the data appears to suggest that the potential for far higher onset temperatures in un-damaged doped graphite exists.Comment: 7 pages, 1 table, 5 figures, 11 references, Acknowledgments section was correcte

Geographical access to radiation therapy in North Queensland: a retrospective analysis of patient travel to radiation therapy before and after the opening of an additional radiotherapy facility

Introduction: Access to radiation therapy (RT) underlies optimal care for prostate and breast cancer patients. This study investigates the impact of opening a new RT clinic on distance and road travel time to RT, and overall utilisation for prostate and breast cancer patients over a 3-year period in North Queensland (NQ), Australia. Methods: The study used retrospective audit of two radiotherapy databases and a geographic information system to illustrate patient origins and distance to the RT clinic used over 3 years. Prostate and female breast cancer patients were selected from the radiation oncology databases of The Townsville Hospital (TTH) and Radiation Oncology Queensland (ROQ) Cairns between 1 July 2010 and 30 June 2013. Distance from a patient's home origin to the RT facility was mapped using a geographic information system (ArcGIS software), and travel time (minutes) and road distance (km) determined by Google Maps road directions. Results: Overall number of prostate and breast cancer patients treated by RT in Cairns and Townsville clinics increased by 16% in 2011–2012 and by 29% in 2012–2013 from year 1 values. In 2010, 44% of the patients travelled 200–400 km to RT, which reduced to 21% in 2013. By 2013, with a second treatment facility, more than 70% of patients lived within 200 km of an RT facility (p<0.0001). Total median road travel time reduced annually from 201 minutes in 2010–2011 to 66 minutes in 2011–2012 and 56 minutes in 2012–2013 (p<0.0001), corresponding to a decrease in the median distance travelled to an RT facility. Conclusions: An additional RT facility in NQ has led to an increase in patients treated with RT for prostate and breast cancer and, on average, less travel distance and time to treatment, suggesting improvement in access to RT in NQ

Self-consistent simulation of high-brightness diode lasers with external optical feedback

This paper presents a model for simulating the impact of external optical feedback on large-optical cavity high-brightness diode lasers. The simulations are performed with our 2.5D simulation tool for high-brightness laser diodes. The external cavity is modelled using commercial coherent ray tracing software. We consider the impact of the optical feedback on the excitation of amplified spontaneous emission in the parasitic vertical modes

Design and simulation of high-speed nanophotonic electro-optic modulators

In this work, an ultracompact electro-optic modulator based on refractive index modulation by plasma dispersion effect in PhC all-optical gate (AOG) is proposed. The index modulation is achieved by applying a time-varying bias voltage across the electrical contacts of the AOG. The proposed modulator has potential for high-speed operation, with bandwidths in excess of 30GHz achievable

Examining area-level variation in service organisation and delivery across the breadth of primary healthcare. Usefulness of measures constructed from routine data

Australia has a universal healthcare system, yet organisation and delivery of primary healthcare (PHC) services varies across local areas. Understanding the nature and extent of this variation is essential to improve quality of care and health equity, but this has been hampered by a lack of suitable measures across the breadth of effective PHC systems. Using a suite of measures constructed at the area-level, this study explored their application in assessing area-level variation in PHC organisation and delivery. Routinely collected data from New South Wales, Australia were used to construct 13 small area-level measures of PHC service organisation and delivery that best approximated access (availability, affordability, accommodation) comprehensiveness and coordination. Regression analyses and pairwise Pearson’s correlations were used to examine variation by area, and by remoteness and area disadvantage. PHC service delivery varied geographically at the small-area level–within cities and more remote locations. Areas in major cities were more accessible (all measures), while in remote areas, services were more comprehensive and coordinated. In disadvantaged areas of major cities, there were fewer GPs (most disadvantaged quintile 0.9[SD 0.1] vs least 1.0[SD 0.2]), services were more affordable (97.4%[1.6] bulk-billed vs 75.7[11.3]), a greater proportion were after-hours (10.3%[3.0] vs 6.2[2.9]) and for chronic disease care (28%[3.4] vs 17.6[8.0]) but fewer for preventive care (50.7%[3.8] had cervical screening vs 62.5[4.9]). Patterns were similar in regional locations, other than disadvantaged areas had less after-hours care (1.3%[0.7] vs 6.1%[3.9]). Measures were positively correlated, except GP supply and affordability in major cities (-0.41, p < .01). Application of constructed measures revealed inequity in PHC service delivery amenable to policy intervention. Initiatives should consider the maldistribution of GPs not only by remoteness but also by area disadvantage. Avenues for improvement in disadvantaged areas include preventative care across all regions and after-hours care in regional locations

Generation–recombination noise in gallium nitride-based quantum well structures

Electronic noise has been investigated in AlxGa1−xN/GaN modulation-doped field-effect transistors of submicron dimensions, grown by molecular beam epitaxy techniques. Some 20 devices were grown on a sapphire substrate. Conduction takes place in the quasi-two-dimensional (2D) layer of the junction (xy plane) which is perpendicular to the triangular quantum well (z direction). A nondoped intrinsic buffer layer separates the Si-doped donors in the AlxGa1−xN layer from the 2D transistor plane. Since all contacts must reach through the AlxGa1−xN layer to connect internally to the 2D plane, parallel conduction through this layer is a feature of all modulation-doped devices. The excess noise has been analyzed as a sum of Lorentzian spectra and 1/fαnoise. The Lorentzian noise is ascribed to trapping of the carriers in the AlxGa1−xN layer. The trap depths have been obtained from Arrhenius plots of log(τT 2)versus 1000/T. Comparison with previous noise results for GaAs devices shows that: (a) many more trapping levels are present in these nitride-based devices and (b) the traps are deeper (farther below the conduction band) than for GaAs, as expected for higher band-gap materials. Furthermore, the magnitude of the noise is strongly dependent on the level of depletion of the AlxGa1−xN donor layer. We also note that the trap-measured energies are in good agreement with the energies obtained by deep level transient spectroscopy

Education research in Australia: where is it conducted?

Research assessment exercises aim to identify research quantity and quality and provide insights into research capacity building strategies for the future. Yet with limited knowledge of the ecology of Australian educational research, there is little chance of understanding what research audits might contribute towards a capacity building agenda for such a complex field. This paper draws on secondary data analysis of research outputs submitted by 13 Australian higher education institutions to the Excellence in Research for Australia (ERA) 2010 and 2012 national research assessment exercises, to show where Australian educational research is conducted. Findings offer a profile of education researchers by location in academic organisational units within universities. By analyzing data not accessible through reported ERA data we were also able to present information about appointment profiles, specifically levels and type of appointment within universities, as well as data on institutional and geographic region, and patterns associated with type of outputs (books, book chapters, journal articles, conference papers and other outputs) and field of research. Analysis of the data reveals definitive shifts in the nature of the published outputs and in employment profiles of researchers and their location across university and regional groupings. Research audits are administrative processes that reshape institutional and disciplinary governance structures, policies, individual outputs, work practices and careers, but they are not the sum total of the field per se

Design optimisation of high-brightness laser diodes for external cavity operation in the BRIDLE project

We report on the design aspects of high performance diode lasers for application in high-brightness spectral beam combining and coherent beam combining modules. Key performance trade-offs are identified and potential solutions are explored

Making the links between domestic violence and child safeguarding:an evidence-based pilot training for general practice

We describe the development of an evidence-based training intervention on domestic violence and child safeguarding for general practice teams. We aimed – in the context of a pilot study – to improve knowledge, skills, attitudes and self-efficacy of general practice clinicians caring for families affected by domestic violence. Our evidence sources included: a systematic review of training interventions aiming to improve professional responses to children affected by domestic violence; content mapping of relevant current training in England; qualitative assessment of general practice professionals' responses to domestic violence in families; and a two-stage consensus process with a multi-professional stakeholder group. Data were collected between January and December 2013. This paper reports key research findings and their implications for practice and policy; describes how the research findings informed the training development and outlines the principal features of the training intervention. We found lack of cohesion and co-ordination in the approach to domestic violence and child safeguarding. General practice clinicians have insufficient understanding of multi-agency work, a limited competence in gauging thresholds for child protection referral to children's services and little understanding of outcomes for children. While prioritising children's safety, they are more inclined to engage directly with abusive parents than with affected children. Our research reveals uncertainty and confusion surrounding the recording of domestic violence cases in families' medical records. These findings informed the design of the RESPONDS training, which was developed in 2014 to encourage general practice clinicians to overcome barriers and engage more extensively with adults experiencing abuse, as well as responding directly to the needs of children. We conclude that general practice clinicians need more support in managing the complexity of this area of practice. We need to integrate and further evaluate responses to the needs of children exposed to domestic violence into general practice-based domestic violence training