An investigation of handwriting legibility and pencil use tasks in healthy older adults

This project explores handwriting legibility and pencil use tasks in 120 healthy older Australian adults, aged 60 to 99 years. A cross sectional study design was used. The aim of these studies was to explore if handwriting legibility or pencil use performance deteriorated as people aged. This is important to help therapists determine if handwriting difficulties following stroke, or other medical conditions, are more likely a consequence of condition-related impairments or due to ‘normal ageing’. Tasks performed under standardised test conditions included writing copied and self-composed sentences, shopping lists, transcribing a telephone message and completing the ‘lines’ and ‘dots’ pencil use Motor Assessment Scale (MAS) subtests. Handwriting legibility was scored using the Modified Four Point Scale-version 2. The first study explored the distribution of handwriting legibility scores in healthy older adults, relationships between handwriting legibility, age and writing task and reliability of rating procedures. Results indicated that handwriting generally remained legible in older adults, regardless of increasing age. The second study explored the performance of older adults without stroke on the ‘lines’ and ‘dots’ tasks, the relationship between age and task performance, and the relationship between writing speed and performance on the ‘lines’ task. Results indicated that many older adults failed the ‘lines’ task and many over 90 years of age failed the ‘dots’ task. Results suggest that impaired handwriting legibility in older adults who have had a stroke (or other medical condition) is likely due to the effects of the medical condition (or the complexity of the task) rather than ‘normal ageing’. However, failure to pass the ‘lines’ and ‘dots’ tasks is likely related to a combination of age and individual skill level and not solely due to condition-related impairment. A revised method for rating performance on the ‘lines’ and ‘dots’ tasks is also proposed

Drift orbits and neoclassical transfort in the H-1NF heliac

This thesis is concerned with neoclassical transport in the H-1NF heliac, and contains an examination of drift-orbit geometries, a description of a neoclassical Monte Carlo transport code, and a description of a method to use that code to self-consistently calculate ambipolar radial electric fields. We set out to study the contributions to neoclassical transport in H-1NF, by first describing the topology and the abundance of collisionless, trapped particle orbits in the presence of radial electric fields. We give an overview of the trapped orbit geometries in H-1NF, and develop a method to numerically classify the trapped particle orbits. On average, the trapped particle fraction in H-1NF is 40%, with approximately 5%, 15%, and 20% of the orbits in the deeply trapped, helically trapped, and toroidally trapped states, respectively. A condensed version of this component of the thesis has been submitted to Nuclear Fusion. The orbit studies provide a background for the development of a neoclassical Monte Carlo transport code, MCMuPPeT (for Monte Carlo, Multi Processing Plasma Transport). Using the code, we compare several Monte Carlo transport diagnostics, taken from the literature. Confinement times and diffusion coefficients are calculated for plasma conditions which will be achievable in H-1NF after the National Facility upgrade. Since the electric field can dominate in the determination of the transport, we develop an iterative method to self-consistently calculate the ambipolar radial electric field, using the Monte Carlo code. The method is applied to the Argon plasma conditions observed in H-1NF, in the experimentally observed Improved Conhnement Mode (ICM). To help interpret the results, the ambipolar electric fields were calculated in the same conditions using a well-known analytic model which was geometrically-fitted to H-1NF for our purposes. Qualitative agreement was found between both of the neoclassical models and the experimental results; the electric fields predicted in the ICM conditions are typically twice as large as those predicted in the conditions before the transition. The two models were also used to look for the neoclassically predicted transition from negative to positive radial electric field. Positive radial electric fields were observed, at long mean free path, in Hydrogen plasma conditions which will be achievable in H-1NF after the National Facility upgrade. We have also developed methods to optimise the Monte Carlo code for both parallel and vector computing environments. Two Message Passing algorithms that we use to parallelise the MC code are presented in the appendix

On the origin of high m magnetospheric waves

A survey of Advanced Rio-Imaging Experiment in Scandinavia data reveals evidence for a previously overlooked generation mechanism of high azimuthal wave number magnetospheric waves. Here we present observations of pulsating cosmic noise absorption with azimuthal wave numbers as high as 380, suggestive of precipitation modulation by magnetospheric waves. Dispersion relations of the small-scale precipitation pulsations are indicative of the proposed origin. Previous studies of magnetospheric waves, together with data from the Charge And Mass Magnetospheric Ion Composition Experiment (Magnetospheric Ion Composition Sensor) instrument aboard the Polar spacecraft, provide support for the theory

Generation and transport of a low energy intense ion beam

The paper describes experiments on the generation and transport of a low energy (70-120 keV), high intensity (10-30 A/cm(2)) microsecond duration H+ ion beam (IB) in vacuum and plasma. The IB was generated in a magnetically insulated diode (MID) with an applied radial B field and an active hydrogen-puff ion source. The annular IB, with an initial density of j(i)similar to10-20 A/cm(2) at the anode surface, was ballistically focused to a current density in the focal plane of 50-80 A/cm(2). The postcathode collimation and transport of the converging IB were provided by the combination of a "concave" toroidal magnetic lens followed by a straight transport solenoid section. With optimized MID parameters and magnetic fields in the lens/solenoid system, the overall efficiency of IB transport at the exit of the solenoid 1 m from the anode was similar to 50% with an IB current density of 20 A/cm(2). Two-dimensional computer simulations of post-MID IB transport supported the optimization of system parameters. (C) 2004 American Institute of Physics

Development and testing of a composite index to monitor the continuum of maternal health service delivery at provincial and district level in South Africa

The continuum of care is a recommended framework for comprehensive health service delivery for maternal health, and it integrates health system and social determinants of health. There is a current lack of knowledge on a measurement approach to monitor performance on the framework. In this study we aim to develop and test a composite index for assessing the maternal health continuum in a province in South Africa with the possibility of nationwide use

Boom and bust in the Latrobe Valley

This thesis argues for the needs of the individual rather than a nationally imposed curriculum that does not take into account the needs of local communities suffering economic dislocation. Educational and socio-economic change are parallel narratives throughout the thesis

Soil Gas Transport in Multiphase Materials for Prediction of Acid Mine Drainage

© 2020 David Cameron DettrickAbstract To assess the economic viability of a proposed mining project, a cost estimate for its mine waste management systems is required, including design and operations of structures such as waste rock dumps, tailing storage facilities and any associated waste treatment systems. In orebodies with sulfide mineralisation, such as coal and base metals, accurate cost estimates are especially important due to the potential high costs of acid mine drainage (AMD) waste management during mine operations and possibly in perpetuity. AMD is generated when sulfides are exposed to oxygen and moisture and sulfide oxidation occurs, creating acid (H2SO4) which can mobilise metals and other toxicants into surface and groundwaters, potentially causing damage to downstream aquatic ecosystems. Currently AMD is assessed and managed using a variety of demand-side, geochemical based testing and modelling techniques, such as humidity cells and leaching columns, which are often expensive, lengthy and complex studies. Due to the limitations of these tests, and the large numbers of parameters involved in geochemical testing and modelling, the results can often still underestimate the effects of AMD, potentially resulting in harm to aquatic ecosystems. The use of a supply-side approach to AMD oxidation, such as oxygen consumption techniques, and soil gas (oxygen) transport, to estimate the potential effects of AMD for mine waste management purposes, has been identified as a useful method that may offer an additional methodology for AMD assessment for geochemical engineers and mine waste managers. This research project seeks to contribute to a new methodology to mine waste management design for AMD mine materials, targeted at the mine design concept and prefeasibility phases. Its principle is based on the use of 1D or 2D soil gas (oxygen) transport models to provide an estimate of potential AMD mine waste volumes that may be oxidised and hence require stabilisation treatment. The soil gas transport models proposed provides for quick, practical and accurate volume assessments in waste rock dumps and waste tailing storage facilities. The proposed method combines lab testing to collect soil gas diffusion data for specific mine wastes, with soil gas transport modelling to test several soil gas diffusion models in 1D and 2D. Several configurations of soil gas diffusion columns were designed and tested over several iterations to provide fast (<3 hours) and economic soil gas diffusion estimates. These columns are designed to be built from commonly available UVPC stormwater pipe materials for less than $500 USD. The method is scalable to any size of project and can provide accurate AMD estimations by collecting additional mine materials soil and rock data for i) soil water characteristic curves (SWCC), ii) soil gas diffusion testing, and iii) soil oxygen penetration column tests. The thesis consists of 8 Chapters: Chapter 1 provides an overview of the problem and the research questions for this project. Chapter 2 presents a critical review of the available literature and Chapter 3 identifies the key knowledge gaps and summarises the research program objectives and work plan. The following three Chapters present results in the form of three journal Papers (two published, one under review) to document the research findings of the project. Chapter 4 presents (Paper i) an introductory Paper to describe the potential pitfalls and impacts of the methodology used for geochemical based AMD mine materials testing and matrix particle size on conceptual mine waste treatment costs. Chapter 5 (Paper ii) presents a comparative assessment of the existing soil gas diffusion coefficient estimation models available in the literature and Chapter 6 (Paper iii) explains the development of a 1D soil gas transport model and testing methodology for AMD mine waste volume determination. Chapter 7 details further development of the 1D model into a 2D finite difference model and demonstrates the additional accuracy of the 2D approach when applied to complex geometries such as sloped or cracked materials and mine waste structures such as tailing storage facilities and waste rock dumps. Chapter 8 presents the key findings and contributions from the research and identifies the key limitations of the work and future research directions. The findings of Paper i highlight the potential for exponential levels of multiplicative error when undertaking geochemical based assessment of AMD materials for treatment and mine closure purposes alone. The use of soil gas diffusion transport models to assess AMD material volumes can potentially contribute to reducing this error by providing additional material volume estimations for comparison, with lower rates of experimental error. Soil gas diffusion testing and related soil gas diffusion models can be compared and checked for potential error across soil and rock matrix types using literature-based diffusion testing results and matrix particle size analysis approaches. The importance of measurement of soil gas diffusion coefficients and the derivation of soil moisture vs soil gas diffusion responses for use in soil gas transport modelling of AMD material response in the mining sector was demonstrated and discussed in Paper ii. Reliance on single material diffusion coefficients, or diffusion coefficient estimation models in the literature was found to be problematic, due to the agricultural basis for these models. The soil gas diffusion risks for agriculture are opposite to that of the mining sector, drying soils with high diffusion coefficients are a risk for mining, while wetting soils with low diffusion coefficients are a risk for agriculture and crop production, and all diffusion coefficient models found in the literature were based on agricultural risk profiles. All commercial soil gas transport models evaluated during the project were found to include either single value diffusion coefficient-based functions, or agriculture-based diffusion coefficient estimation functions. A 1D soil gas diffusion model and methodology for assessing AMD impacted mine materials is presented in Paper iii. The Paper builds on the soil gas diffusion column method shown in Paper ii by adding an oxygen penetration column test to derive the boundary conditions required for the 1D model. The 1D model is used to evaluate the performance of several diffusion coefficient estimation models available in the literature. The discussion highlights the potential limitations and agricultural bias for several existing diffusion coefficient estimation models, analysis of possible dual diffusion functions based on soil matrix geometry and particle size and proposes the use of safety factors to ensure AMD material volume assessments are suitably conservative. The development of a simple spreadsheet based, finite difference 2D soil gas transport model derived from the 1D model is documented in Chapter 7. The 2D model was designed to work with measured soil moisture/diffusion coefficient models, single value diffusion coefficients, or diffusion coefficient models from the literature. Statistical 2D model performance evaluation was undertaken, and the results demonstrate the additional capability of the 2D model to provide accurate volume assessments of potentially AMD affected mine waste materials with complex geometries such as cracks and fractures, when using the soil gas diffusion transport method provided by this research project. The 2D model results again highlighted the importance of measurement of soil gas diffusion coefficient at several material moisture levels to provide a realistic soil gas diffusion model result for accurate geochemical and waste management design with AMD materials. The overall conclusion of the research project is that the use of the proposed soil gas diffusion measurement and modelling methodology provides a potential fast, economic and more accurate alternative to the complex suite of geochemical assessment methods currently used to estimate the rate of sulfide oxidation. The method is useful for assessing concept and prefeasibility mine design estimates of volumes of AMD mine materials and waste potentially requiring treatment. Testing the AMD mine materials for soil gas diffusion behaviour at a range of moisture levels provides the most accurate results, as many diffusion coefficient models available in the literature may underestimate AMD oxidation. The soil gas diffusion method is presented with an accuracy hierarchy, and the use of safety factors is explored to replace diffusion testing if use of the complete soil diffusion and oxygen penetration testing method presented in this thesis is not possible. When combined with detailed level geochemical assessments, the method offers a complimentary data source, suitable for detailed and final design of AMD waste management and treatment systems

Use of microbubble contrast in the diagnosis of a left ventricular papillary fibroelastoma

A papillary fibroelastoma is a rare, avascular, cardiac tumour that is often found incidentally using transthoracic echocardiography (TTE). Peripheral i.v. injection of a microbubble contrast agent is often used to characterize abnormal masses within the heart allowing further delineation of physical features, the area of attachment, and vascularity of the mass in order to differentiate the growth from a tumour or a thrombus. This case highlights a potential pitfall when assessing a cardiac tumour's vascularity using contrast TTE. A cardiac mass was identified on a TTE of a 53-year-old man and was further investigated with microbubble contrast-enhanced TTE. Contrast TTE imaging suggested a vascularized structure in the left ventricle. However, after histological examination the tumour was found to be entirely avascular