529 research outputs found

    The National Small Wind Turbine Centre

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    In August 2008, the Federal government announced funding for a National Small Wind Turbine Centre (NSWTC) to be operated by the Research Institute of Sustainable Energy (RISE), based at Murdoch University in Perth, Western Australia. The aim of the NSWTC is to promote the small wind turbine (SWT) market and industry in Australia by providing services in the areas of Testing, Standards and Labelling, Professional Development and Training, and Research. This paper summarises the work that has been carried out to date by the NSWTC in the area of Standards and Labelling. Existing certification and labelling schemes for SWTs are summarised and an overview is given of the NSWTC participation in the International Energy Agency (IEA) Task 27, a task aimed at research that will advance standards, improve the quality of SWT testing around the globe and lead to an international consumer label for SWTs. Options for certification and labelling for the emerging Australian SWT industry are analysed and the idea of introducing an Australian consumer label for SWTs is discussed

    Analysis of turbulence and vortex structures by flow mapping

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    The technique of Particle Image Velocimetry (PIV) flow mapping is reviewed and comparisons made with Laser Doppler Anemometry (LDA). Results are presented showing the application of PlV to the determination of coherent structures in grid-generated turbulence and theoretical expressions are presented for the errors associated with the computation of statistical parameters. Measurements are also presented showing the vortex structure in the wake of a model wind turbine. These studies have revealed fundamental inadequacies in existing computer codes used by the wind turbine industry

    Analyzing Harmonic Polarities: A Tonal Narrative Approach

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    This dissertation aims to develop an approach to analyzing common-practice repertoire based on the dynamic interplay of centripetal and centrifugal forces. It aims at interpreting various kinds of chromaticism and modulation in terms of the interaction of forces moving away from the tonic or principal key (centrifugal) and those returning to it (centripetal). Centripetal forces also correspond to the force of cadential substantiation of keys, not only the principal key, which I call temporal-centripetal force; temporal-centrifugal forces correspond to the phenomena of tonal instability, of motion through multiple regions. The dynamic interplay and counterbalancing of these forces is a core concern of the dissertation. In chapter 1 I build upon Arnold Schoenberg\u27s visionary metaphor for modulation as a struggle and a competition between the tonic and its regions, imagined as a sovereign ruler and his subjects. The tendencies of the regions generate centrifugal forces; the ruling tonic\u27s desire to subjugate them correspond to centripetal forces. What I call temporal-centripetal forces correspond to the possibility for temporary centripetal forces to be generated by a region, which becomes the ruler of its own realm. The crucial application to analyzing harmonic motion is that centripetal and centrifugal forces are dynamically interdependent; each requires the other in order to stimulate a living tonal narrative. In order to measure centrifugal forces, the tonal narrative approach draws on Gottfried Weber and Schoenberg\u27s maps of tonal space and Weber\u27s elucidation of degrees of relatedness between keys, which are explored in chapter 2. Centrifugal forces divide into sharp and flat sides or types, which correspond to very general character and coloristic shades: sharp-centrifugal forces associate with brightening and greater activity and flat-centrifugal forces with darkening and sometimes passivity. In chapter 3, I explore how the harmonic motion of entire movements can be divided into distinctive functions that define their overall shape, such as intensifications (accumulations of dissonance or centrifugal force or both), culminations, counterbalancing of sharp- and flat-CF forces, and the attainment a complete tour of keys or regions in the tonal spectrum. This chapter also offers a hierarchy of key-area substantiation, determining the structural significance of regions appearing in tonal narratives. Chapter 4 interprets sonata form in terms of centripetal and centrifugal forces unfolding in broad stages, which often correspond with formal parts but sometimes cross their boundaries. It examines the expansion of centrifugal trajectories in piano sonata development sections by Mozart and Beethoven; the culmination of this expansion is the complete traversal of the enharmonic circle in the Waldstein sonata (first movement). I analyze this development section in terms of the number of fundamental steps travelled from the subordinate key to the point of furthest remove. Chapter 5 develops a hermeneutic reading of Schubert\u27s sonata D. 894/i; centrifugal and centripetal forces are matched to pastoral/epic expressive modes identified in this movement by Robert Hatten. This work also features an immense modulatory trajectory around the enharmonic circle, corresponding to an epic narrative journey into the tonal underworld. A remarkable aspect of the development section is the transient recurrences of passages returning to the pastoral mode and centripetal forces; these provide a welcome contrast and respite from the inexorable flatward trajectory. The conclusion of the dissertation briefly offers some applications of analyzing harmonic polarities to piano performance, drawing particularly on aspects of touch and technique discussed by Boris Berman

    Generalizations of the Abstract Boundary singularity theorem

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    The Abstract Boundary singularity theorem was first proven by Ashley and Scott. It links the existence of incomplete causal geodesics in strongly causal, maximally extended spacetimes to the existence of Abstract Boundary essential singularities, i.e., non-removable singular boundary points. We give two generalizations of this theorem: the first to continuous causal curves and the distinguishing condition, the second to locally Lipschitz curves in manifolds such that no inextendible locally Lipschitz curve is totally imprisoned. To do this we extend generalized affine parameters from C1C^1 curves to locally Lipschitz curves.Comment: 24 page

    Wind power variations during storms and their impact on balancing generators and carbon emissions in the Australian National Electricity Market

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    This paper examines changes in Frequency Control Ancillary Services (FCAS) generator output due to several large wind farm power variations occurring in the Australian National Electricity Market (NEM) during 2012 and 2013. Using data from actual FCAS generator output fluctuations during selected storm events and reconstructed heat rate curves for each FCAS generator, the authors address the research question of what effect such variations have on net carbon emissions from electricity generation, given balancing fossil-fueled FCAS generators will be pushed back into less efficient operating ranges. The study finds that, for all storm events evaluated, net carbon emissions decreased with each large increase in wind power, even though FCAS generator carbon intensity increased in two of the three events. This finding is consistent with the conclusions of other studies that while FCAS generators do move into less efficient operating ranges, the generation of zero carbon emission wind power displaces other fossil fuel generators and more than compensates for this efficiency reduction, creating an overall positive carbon effect. This is a significant finding as it shows that the inclusion of wind farms in the generation mix serving the Australian NEM can lower carbon emissions in both short and long time frames

    Population Genetics of the blow fly Phormia regina (Meigen)

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    poster abstractBlow flies (Diptera: Calliphoridae) are a family of flies which are associated with the decomposition of organic matter, and the many species are widely distributed across the globe inhabiting almost every ecosystem and continent, with the exception being Antarctica. For many years, biologists have been interested in these metamorphic insects with much attention in recent years with their predictable life cycle and subsequent application in death investigations. Phormia regina (Meigen) is a primary colonizer of carrion and is widely distributed across the United States and can be found throughout the year. Recently, molecular techniques have been applied to a number of blow fly species, initially for identification purposes to corroborate morphological taxonomy but also as an alternative to morphology when specimens are damaged. Even more recently, population structure of these flies have been investigated, however these studies have primarily focused on pest species which infest living livestock and directly affect the agricultural economy. Here, we build upon previous analysis with AFLP markers on P. regina to determine the population structure of this integral species by using tetra-nucleotide microsatellite markers. From the recently constructed draft genome of P. regina, several thousand tetra-nucleotide (four-base repeating sequences of DNA) were identified. Due to the high A-T content of insect DNA, repeats consisting wholly of adenine and thymine bases were discarded. From the remaining tetra-repeats, 14 were chosen for initial analysis to determine their polymorphic nature; from here six were selected for genotypic analysis. More than 200 different P. regina individuals belonging to 27 populations collected from across the contiguous United States have been genotyped across these six tetra-nucleotide loci. Five loci possess ≥30 different alleles, while the sixth appears to be fairly conserved with eight different alleles. Heterozygosity exhibited between these populations is uniform (0.5-0.8) while inbred lab colonies exhibit an increase in homozygosity from their ancestral population. Further analyses are to be performed in order to determine the population structure and geography-genetic relationships of these flies

    Battery cell balance of electric vehicles under fast-DC charging

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    Electric vehicle (EV) range, recharge opportunities and time to recharge are major barriers to mainstream acceptance. Fast-DC charging has the potential to overcome these barriers. This research investigates the impact of fast-DC charging on battery cell balance, charge capacity and range for an EV travelling long distances on an 'electric-highway'. Two commercially available EVs were exposed to a series of discharge and fast-DC charge cycles to measure cell balance and charge capacity. The vehicles' battery management systems (BMS) were capable of successfully balancing individual cells and hence maintaining the batteries' charge capacity. Although fast-DC charge levels and discharge safety margins significantly reduced the vehicles' charge capacity and range as stated by the manufacturer, these values remained stable for the test period. In regards to cell balance and charge capacity, our research suggests that fast-DC charging technology is a feasible option for EVs to travel large distances in a day

    Context and community renewable energy development in Western Australia: Towards effective policy and practice

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    Community renewable energy projects are contributing diverse sustainability benefits in a transforming energy landscape, but in Western Australia, projects are few and far between and the state is being left behind in national policy discussions. Drawing upon a socio-technical framework which conceptualises the context of innovation journeys according to patterns in the context, we investigate Western Australia and its major electricity network as a site for community-driven renewable energy development. Our case-study analysis suggests that project development in Western Australia to date has survived in niche pockets, which have been unusually conducive to community energy development, in a context otherwise riddled with political, technical, and regulatory hurdles

    Benchmarking a sustainable energy engineering undergraduate degree against curriculum frameworks and pedagogy standards from industry and academia

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    There is an urgent need for educational institutions to produce graduates with appropriate skills to meet the growing global demand for professionals in the sustainable energy industry. For universities to stay at the forefront of meeting this global demand from industry, universities need to ensure their curricula and pedagogies stay relevant. The use of benchmarking is a key means of achieving this and ensuring any gap between university curricula and the practical needs of industry is minimized. The aim of this paper is to present an approach to benchmarking a sustainable energy engineering undergraduate degree with respect to curriculum frameworks recommended by industry and pedagogy standards required and recommended by academia and education research. The method uses the Murdoch University renewable energy engineering degree major as a case study. The results show that the learning outcomes of the renewable energy engineering units, in general, align well with the recommended learning outcomes for a complete sustainable energy degree, as prescribed by the Australian Government Office for Learning and Teaching. In addition, assessment task and marking criteria for the capstone unit of the major were at Australian Universities’ standard. A similar approach to benchmarking can be adopted by developers of new or existing sustainable energy engineering degrees in order to align with curriculum frameworks and pedagogy standards required by industry and academic peers
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