High-voltage MOSFET bipolar square-wave generator

he construction of a high‐voltage (up to 1000 V) bipolar metal‐oxide‐semiconductor field‐effect transistor square‐wave generator is described. This generator is capable of producing both positive and negative going square waves with variable amplitude, repetition rate, and width. The circuit was designed for ferroelectrics research, however other applications are possible. The rise time of the prototype was 200 ns which was quite satisfactory for the present ferroelectric research project however the rise time can be decreased to 50 ns if necessary. The reader with a modest knowledge of electronics should be able to construct the circuit. Possible pitfalls and critical points are discussed

Quantum Hall induced currents and the magnetoresistance of a quantum point contact

We report an investigation of quantum Hall induced currents by simultaneous measurements of their magnetic moment and their effect on the conductance of a quantum point contact (QPC). Features in the magnetic moment and QPC resistance are correlated at Landau-level filling factors nu=1, 2 and 4, which demonstrates the common origin of the effects. Temperature and non-linear sweep rate dependences are observed to be similar for the two effects. Furthermore, features in the noise of the induced currents, caused by breakdown of the quantum Hall effect, are observed to have clear correlations between the two measurements. In contrast, there is a distinct difference in the way that the induced currents decay with time when the sweeping field halts at integer filling factor. We attribute this difference to the fact that, while both effects are sensitive to the magnitude of the induced current, the QPC resistance is also sensitive to the proximity of the current to the QPC split-gate. Although it is clearly demonstrated that induced currents affect the electrostatics of a QPC, the reverse effect, the QPC influencing the induced current, was not observed

Conquering the great divide: Rural mothers of children with chronic health conditions accessing specialist medical care for their children

© 2019 Australian College of Nursing Ltd Background: Globally, the number of children with chronic health conditions (CHCs) is increasing and mothers are mostly responsible for their care. Aim: Few studies have focused on rural mothers and their experiences of sourcing health care for their children who have CHCs. The purpose of this study was to explore these experiences. Method: Using a phenomenological approach, semi-structured interviews were conducted in early 2018. The Consolidated criteria for Reporting Qualitative research (COREQ) guidelines were followed. Sixteen rural mothers were interviewed regarding their experiences of accessing health care to provide optimal management of their children's CHC. Findings: Thematic analysis of resulting data revealed the overarching theme ‘Conquering the great divide’. From this overarching theme, four themes emerged. This paper focuses on the first theme, ‘Heading to the big smoke: access’. Discussion: Rural mothers felt challenged accessing health care for their children in the major cities whilst also maintaining routine family life back home. Conclusion: Understanding these rural women's experiences could assist health care professionals to develop strategies to facilitate rural mothers accessing services for their children with a CHC

Causal Responsibility and Robust Causation

How do people judge the degree of causal responsibility that an agent has for the outcomes of her actions? We show that a relatively unexplored factor – the robustness (or stability) of the causal chain linking the agent’s action and the outcome – influences judgments of causal responsibility of the agent. In three experiments, we vary robustness by manipulating the number of background circumstances under which the action causes the effect, and find that causal responsibility judgments increase with robustness. In the first experiment, the robustness manipulation also raises the probability of the effect given the action. Experiments 2 and 3 control for probability-raising, and show that robustness still affects judgments of causal responsibility. In particular, Experiment 3 introduces an Ellsberg type of scenario to manipulate robustness, while keeping the conditional probability and the skill deployed in the action fixed. Experiment 4, replicates the results of Experiment 3, while contrasting between judgments of causal strength and of causal responsibility. The results show that in all cases, the perceived degree of responsibility (but not of causal strength) increases with the robustness of the action-outcome causal chain

Analysis of line x environment interactions for yield in navy beans. 3. Pattern analysis of environments over years

Yield trials of navy bean (Phaseolus vulgaris L.) lines were grown over a diverse range of locations for 7 years in Queensland, with changes in entries and locations in each year. The yield data were analysed over years using 3 recently developed pattern analysis techniques for the integration of historical, severely unbalanced data from plant breeding programs to derive relationships among environments in the way they discriminate among the entries grown in them. These techniques have been named as cumulative analysis, sequential analysis, and status analysis. The relationships among the locations for testing navy bean lines, although sensitive to the addition of new locations, quickly stabilised. These relationships were related to management (irrigation and row width) and latitude (north v. central v. Kingaroy v. southern Queensland)

Gamma Ray Large Area Space Telescope (GLAST) Balloon Flight Data Handling Overview

The GLAST Balloon Flight Engineering Model (BFEM) represents one of 16 towers that constitute the Large Area Telescope (LAT), a high-energy (>20 MeV) gamma-ray pair-production telescope being built by an international partnership of astrophysicists and particle physicists for a satellite launch in 2006. The prototype tower consists of a Pb/Si pair-conversion tracker (TKR), a CsI hodoscopic calorimeter (CAL), an anti-coincidence detector (ACD) and an autonomous data acquisition system (DAQ). The self-triggering capabilities and performance of the detector elements have been previously characterized using positron, photon and hadron beams. External target scintillators were placed above the instrument to act as sources of hadronic showers. This paper provides a comprehensive description of the BFEM data-reduction process, from receipt of the flight data from telemetry through event reconstruction and background rejection cuts. The goals of the ground analysis presented here are to verify the functioning of the instrument and to validate the reconstruction software and the background-rejection scheme.Comment: 5 pages, 4 figures, to be published in IEEE Transacations on Nuclear Science, August 200

Influence of COVID-19 on the preventive health behaviours of indigenous peoples of Australia residing in New South Wales: a mixed-method study protocol.

Introduction Chronic conditions impact Indigenous Peoples of Australia at a much higher rate than non-Indigenous Australians. Attendance at the Medicare Benefits Scheme (MBS) supported Indigenous health checks are crucial to improve prevention and management of chronic health conditions. However, in conjunction with lifestyle and environmental factors, attendance rates at primary healthcare services for screening and treatment have fallen in Australia during the COVID-19 pandemic. This study aims to explore the influence of the COVID-19 pandemic on preventive health behaviours of Indigenous Australians and the associated barriers to, and enablers of, engagement with health services to formulate a targeted intervention strategy. Methods and analysis A concurrent mixed-methods study (comprising quantitative and qualitative data collection methods) will be employed. Descriptive analysis of MBS data about the characteristics of Indigenous Peoples of Australia claiming health assessment services will be performed. Generalised estimating equation regression models will be used to examine the use of health assessment services over time. Qualitative interviews informed by Indigenous research methods will be conducted. Interviews will investigate barriers to, and enablers of, engagement with health services. Thematic approach guided by the principles of indigenist praxis, storytelling and collaborative research will be used to analyse the interview data. The project commenced in July 2020 and will be completed by July 2022. Ethics and dissemination The project received ethics approval from the Aboriginal Health and Medical Research Council of New South Wales and the University of New England Human Research Ethics Committee. Findings will be disseminated via peer-reviewed journal articles, conferences, government and relevant stakeholder reports, and infographics

Thermal and Tunneling Pair Creation of Quasiparticles in Quantum Hall Systems

We make a semiclassical analysis of thermal pair creations of quasiparticles at various filling factors in quantum Hall systems. It is argued that the gap energy is reduced considerably by the Coulomb potential made by impurities. It is also shown that a tunneling process becomes important at low temperature and at strong magnetic field. We fit typical experimental data excellently based on our semiclassical results of the gap energy.Comment: 6 pages, 6 PS figures, to be published in Phys.Rev.

Semisimplicity of the quantum cohomology for smooth Fano toric varieties associated with facet symmetric polytopes

The degree zero part of the quantum cohomology algebra of a smooth Fano toric symplectic manifold is determined by the superpotential function, W, of its moment polytope. In particular, this algebra is semisimple, i.e. splits as a product of fields, if and only if all the critical points of W are non-degenerate. In this paper we prove that this non-degeneracy holds for all smooth Fano toric varieties with facet-symmetric duals to moment polytopes.Comment: 16 pages; corrected version, published in Electron. Res. Announc. Math. Sc

Heat Capacity Evidence for the Suppression of Skyrmions at Large Zeeman Energy

Measurements on a multilayer two-dimensional electron system (2DES) near Landau level filling $\nu$=1 reveal the disappearance of the nuclear spin contribution to the heat capacity as the ratio $\tilde{g}$ between the Zeeman and Coulomb energies exceeds a critical value $\tilde{g}_c \approx$0.04. This disappearance suggests the vanishing of the Skyrmion-mediated coupling between the lattice and the nuclear spins as the spin excitations of the 2DES make a transition from Skyrmions to single spin-flips above $\tilde{g}_c$. Our experimental $\tilde{g}_c$ is smaller than the calculated $\tilde{g}_c$=0.054 for an ideal 2DES; we discuss possible origins of this discrepancy.Comment: Experimental paper, 6 figure