77 resultados para Stars: winds, outflows

em Queensland University of Technology - ePrints Archive


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Environmental impacts caused during Australia's comparatively recent settlement by Europeans are evident. Governments (both Commonwealth and States) have been largely responsible for requiring landholders – through leasehold development conditions and taxation concessions – to conduct clearing that is now perceived as damage. Most governments are now demanding resource protection. There is a measure of bewilderment (if not resentment) among landholders because of this change. The more populous States, where most overall damage has been done (i.e. Victoria and New South Wales), provide most support for attempts to stop development in other regions where there has been less damage. Queensland, i.e. the north-eastern quarter of the continent, has been relatively slow to develop. It also holds the largest and most diverse natural environments. Tree clearing is an unavoidable element of land development, whether to access and enhance native grasses for livestock or to allow for urban developments (with exotic tree plantings). The consequences in terms of regulations are particularly complex because of the dynamic nature of vegetation. The regulatory terms used in current legislation – such as 'Endangered' and 'Of concern' – depend on legally-defined, static baselines. Regrowth and fire damage are two obvious causes of change. A less obvious aspect is succession, where ecosystems change naturally over long timeframes. In the recent past, the Queensland Government encouraged extensive tree-clearing e.g. through the State Brigalow Development Scheme (mostly 1962 to 1975) which resulted in the removal of some 97% of the wide-ranging mature forests of Acacia harpophylla. At the same time, this government controls National Parks and other reservations (occupying some 4% of the State's 1.7 million km2 area) and also holds major World Heritage Areas (such as the Great Barrier Reef and the Wet Tropics Rainforest) promulgated under Commonwealth legislation. This is a highly prescriptive approach, where the community is directed on the one hand to develop (largely through lease conditions) and on the other to avoid development (largely by unusable reserves). Another approach to development and conservation is still possible in Queensland. For this to occur, however, a more workable and equitable solution than has been employed to date is needed, especially for the remote lands of this State. This must involve resident landholders, who have the capacity (through local knowledge, infrastructure and daily presence) to undertake most costeffectively sustainable land-use management (with suitable attention to ecosystems requiring special conservation effort), that is, provided they have the necessary direction, encouragement and incentive to do so.

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This booklet is the third in the Research in Practice Series, designed to complement Belonging, being & becoming: The Early Years Learning Framework for Australia (DEEWR, 2009). It focuses on Learning Outcome 5 of the Early Years Learning Framework (EYLF): Children are effective communicators (DEEWR, 2009).

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Winds of Change is a short film that contrasts the Tragic Tale of Surachai by tracing the life of a rural Australian man who is left a quadriplegic after a near fatal motorcycle accident. The film highlights issues confronting people living with a disability and its impact on family. This film was developed to raise discussion amongst students studying social work and human services at Queensland University of Technology.

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An important component of current models for interstellar and circumstellar evolution is the infrared (IR)spectral data collected from stellar outflows around oxygen-rich stars and from the general interstellar medium [1]. IR spectra from these celestial bodies are usually interpreted as showing the general properties of sub-micron sized silicate grains [2]. Two major features at 10 and 20 microns are reasonably attributed to amorphous olivine or pyroxene (e.g. Mg2Si04 or MgSi03) on the basis of comparisons with natural standards and vapor condensed silicates [3-6]. In an attempt to define crystallisation rates for spectrally amorphous condensates, Nuth and Donn [5] annealed experimentally produced amorphous magnesium silicate smokes at 1000K. On analysing these smokes at various annealing times, Nuth and Donn [5] showed that changes in crystallinity measured by bulk X-ray diffraction occured at longer annealing times (days) than changes measured by IR spectra (a few hours). To better define the onset of crystallinity in these magnesium silicates, we have examined each annealed product using a JEOL 1OOCX analytical electron microscope (AEM). In addition, the development of chemical diversity with annealing has been monitored using energy dispersive spectroscopy of individual grains from areas <20nm in diameter. Furthermore, the crystallisation kinetics of these smokes under ambient, room temperature conditions have been examined using bulk and fourier transform infrared (FTIR)spectra.

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During an investigation on thin steel roof claddings under simulated cyclonic wind loading, it was found that trapezoidal roof claddings behaved quite differently to corrugated (arc and tangent type) roof claddings due to the presence of overload cycles. The overload cycles caused a reduction in fatigue life for corrugated roofing whereas the reverse occurred for trapezoidal roofing. This contrasting behavior of the two crest-fixed roof claddings was investigated using small scale roofing models instead of the commonly used large scale two-span roof claddings. It was found that overload cycles formed a weaker locally dimpled mechanism around the fastener holes of corrugated roofing and thus accelerated the fatigue-caused pull-through failure. In contrast, a stronger deformed shape was formed in trapezoidal roofing which delayed the pull-through failure. Both laboratory testing and finite element analysis of small scale models were used to study the contrasting behavior of roof claddings.

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The wind field of an intense idealised downburst wind storm has been studied using an axisymmetric, dry, non-hydrostatic numerical sub-cloud model. The downburst driving processes of evaporation and melting have been paramaterized by an imposed cooling source that triggers and sustains a downdraft. The simulated downburst exhibits many characteristics of observed full-scale downburst events, in particular the presence of a primary and counter rotating secondary ring vortex at the leading edge of the diverging front. The counter-rotating vortex is shown to significantly influence the development and structure of the outflow. Numerical forcing and environmental characteristics have been systematically varied to determine the influence on the outflow wind field. Normalised wind structure at the time of peak outflow intensity was generally shown to remain constant for all simulations. Enveloped velocity profiles considering the velocity structure throughout the entire storm event show much more scatter. Assessing the available kinetic energy within each simulated storm event, it is shown that the simulated downburst wind events had significantly less energy available for loading isolated structures when compared with atmospheric boundary layer winds. The discrepancy is shown to be particularly prevalent when wind speeds were integrated over heights representative of tall buildings. A similar analysis for available full scale measurements led to similar findings.

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Convectively driven downburst winds pose a threat to structures and communities in many regions of Australia not subject to tropical cyclones. Extreme value analysis shows that for return periods of interest to engineering design these events produce higher gust wind speeds than synoptic scale windstorms. Despite this, comparatively little is known of the near ground wind structure of these potentially hazardous windstorms. With this in mind, a series of idealised three-dimensional numerical simulations were undertaken to investigate convective storm wind fields. A dry, non-hydrostatic, sub-cloud model with parameterisation of the microphysics was used. Simulations were run with a uniform 20 m horizontal grid resolution and a variable vertical resolution increasing from 1 m. A systematic grid resolution study showed further refinement did not alter the morphological structure of the outflow. Simulations were performed for stationary downbursts in a quiescent air field, stationary downbursts embedded within environmental boundary layer winds, and also translating downbursts embedded within environmental boundary layer winds.

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This research investigates the prevalence of sports-related terms among the Web sites of the world’s leading companies, the Fortune Global 500. An automated process copied about four gigabytes of textual data, around 70 million words, from their sites. The subsequent analysis revealed regional and industry differences in the distribution of sports-related terms, the popularity of tennis stars and few references to sports stars, especially in Asia.

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In this chapter, we frame YouTube as an example of “co-creative” culture – whatever YouTube is, it is produced dynamically (that is, as an ongoing process, over time) as a result of many interconnected instances of participation, by many different people. In order to understand these co-creative relationships, it is important not to focus exclusively on how the “ordinary consumer” or “amateur producer,” are participating in YouTube; rather, we argue it is necessary to include the activities of “traditional media” companies and media professionals, and more importantly, the new models of media entrepreneurialism that are grounded in YouTube’s “grassroots” culture. Hence, this chapter focuses the role that “YouTube stars” – highly visible and successful “homegrown” performers and producers – play in modelling and negotiating these co-creative relationships within the context of YouTube’s social network; and the new models of entrepreneurship within participatory culture that they represent.

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This paper describes the current status of a program to develop an automated forced landing system for a fixed-wing Unmanned Aerial Vehicle (UAV). This automated system seeks to emulate human pilot thought processes when planning for and conducting an engine-off emergency landing. Firstly, a path planning algorithm that extends Dubins curves to 3D space is presented. This planning element is then combined with a nonlinear guidance and control logic, and simulated test results demonstrate the robustness of this approach to strong winds during a glided descent. The average path deviation errors incurred are comparable to or even better than that of manned, powered aircraft. Secondly, a study into suitable multi-criteria decision making approaches and the problems that confront the decision-maker is presented. From this study, it is believed that decision processes that utilize human expert knowledge and fuzzy logic reasoning are most suited to the problem at hand, and further investigations will be conducted to identify the particular technique/s to be implemented in simulations and field tests. The automated UAV forced landing approach presented in this paper is promising, and will allow the progression of this technology from the development and simulation stages through to a prototype system

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This chapter analyses the affordances and constraints of an online literacy program designed for Indigenous Australian youth through a partnership between the Indigenous community, university staff and local schools. The after-school program sought to build on the cultural resources and experiences of the young people through a dialogic process of planning, negotiating, implementing, reflecting, and renegotiating the program with participants and a range of stakeholders. In the majority of cases, students presented themselves as part of pervasive global popular cultures, often hot-linking their webpages to pop icons and local sports stars. Elders regarded their competency as a potential cultural tool and community resource.

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Disco Puppy is an energetic interactive installation for children (and parents) which stars three larger than life dancing puppies. The work was initially produced for the Ipswich Art Gallery and has since toured nationally.

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The author's approach to the problems associated with building in bushfire prone landscapes comes from 12 years of study of the biophysical and cultural landscapes in the Great Southern Region of Western Australia - research which resulted in the design and construction of the H-house at Bremer Bay. The house was developed using a 'ground up' approach whereby Dr Weir conducted topographical surveys and worked with a local botanist and a bushfire risk consultant to ascertain the level of threat that fire presented to this particular site. The intention from the outset however, was not to design a bushfire resistant house per se, but to develop a design which would place the owners in close proximity to the highly biodiverse heath vegetation of their site. The research aim was to find ways - through architectural design-to link the patterns of usage of the house with other site specific conditions related to the prevailing winds, solar orientation and seasonal change. The H-house has a number of features which increase the level of bushfire safety. These include: Fire rated roller shutters (tested by the CSIRO for ember attack and radiant heat), Fire resistant double glazing (on windows not protected by the shutters), Fibre-cement sheet cladding of the underside of the elevated timber floor structure, Manually operated high pressure sprinkler system on exposed timber decks, A fire refuge (an enlarged laundry, shower area) within the house with a dedicated cabinet for fire fighting equipment) and A low pressure solar powered domestic water supply system.