957 resultados para bending-under-tension
Resumo:
Australian copyright law is broken, and the Australian Government isn’t moving quickly to fix it. Borrowing, quoting, and homage are fundamental to the creative process. This is how people are inspired to create. Under Australian law, though, most borrowing is copyright infringement, unless it is licensed or falls within particular, narrow categories. This year marks five years since the very real consequences of Australia’s restrictive copyright law for Australian artists were made clear in the controversial litigation over Men at Work’s 1981 hit Down Under. The band lost a court case in 2010 that found that the song’s iconic flute riff copied some of the 1934 children’s song Kookaburra Sits in the Old Gumtree. A new book and documentary tell us more about the story behind the anthem – and the court case. The book, Down Under by Trevor Conomy, and the documentary, You Better Take Cover by Harry Hayes, bring renewed interest and new perspectives on the tragic story.
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Recent research on hollow flange beams has led to the development of an innovative rectangular hollow flange channel beam (RHFCB) for use in floor systems. The new RHFCB is a mono-symmetric structural section made by intermittently rivet fastening two torsionally rigid closed rectangular hollow flanges to a web plate element, which allows section optimisation by selecting appropriate combinations of web and flange widths and thicknesses. However, the current design rules for cold-formed steel sections are not directly applicable to rivet fastened RHFCBs. To date, no investigation has been conducted on their web crippling behaviour and strengths. Hence an experimental study was conducted to investigate the web crippling behaviour and capacities of rivet fastened RHFCBs under End Two Flange (ETF) and Interior Two Flange (ITF) load cases. It showed that RHFCBs failed by web crippling, flange crushing and their combinations. Comparison of ultimate web crippling capacities with the predictions from the design equations in AS/NZS 4600 and AISI S100 showed that the current design equations are unconservative for rivet fastened RHFCB sections under ETF and ITF load cases. Hence new equations were proposed to determine the web crippling capacities of rivet fastened RHFCBs. These equations can also be used to predict the capacities of RHFCBs subject to combined web crippling and flange crushing conservatively. However, new capacity equations were proposed in the case of flange crushing failures that occurred in thinner flanges with smaller bearing lengths. This paper presents the details of this web crippling experimental study of RHFCB sections and the results.
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This paper presents the details of experimental studies on the effect of real support conditions on the shear strength of hollow flange channel beams, known as LiteSteel beams (LSB). The LSB has a unique shape of a channel beam with two rectangular hollow flanges, made using a unique manufacturing process. In many applications in the building industry LSBs are used with only one web side plate (WSP) at their supports. The WSPs are also often not full height plates. Past research studies showed that these real support connections did not provide the required simply supported conditions. Many studies have been carried out to evaluate the behaviour and design of LSBs with simply supported conditions subject to pure bending and predominant shear actions. To date, however, no investigation has been conducted into the effect of real support conditions on the shear strength of LSBs. Hence a detailed experimental study based on 25 shear tests was undertaken to investigate the shear behaviour and strength of LSBs with real support conditions. Simply supported test specimens of LSBs with aspect ratios of 1.0 and 1.5 were loaded at mid-span until failure. It was found that the effect of using one WSP on the shear behaviour of LSB is significant and there is about 25% shear capacity reduction due to the lateral movement of the bottom flange at the supports. Shear capacity of LSB was also found to decrease when full height WSPs were not used. Suitably improved support connections were developed to improve the shear capacity of LSBs based on test results. Details of the recommended support connections and shear capacity results are given in this paper.
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Introducing nitrogen (N)-fixing legumes into cereal-based crop rotations reduces synthetic fertiliser-N use and may mitigate soil emissions of nitrous oxide (N2O). Current IPCC calculations assume 100% of legume biomass N as the anthropogenic N input and use 1% of this as an emission factor (EF)—the percentage of input N emitted as N2O. However, legumes also utilise soil inorganic N, so legume-fixed N is typically less than 100% of legume biomass N. In two field experiments, we measured soil N2O emissions from a black Vertosol in sub-tropical Australia for 12 months after sowing of chickpea (Cicer arietinum L.), canola (Brassica napus L.), faba bean (Vicia faba L.), and field pea (Pisum sativum L.). Cumulative N2O emissions from N-fertilised canola (624 g N2O-N ha−1) greatly exceeded those from chickpea (127 g N2O-N ha−1) in Experiment 1. Similarly, N2O emitted from canola (385 g N2O-N ha−1) in Experiment 2 was significantly greater than chickpea (166 g N2O-N ha−1), faba bean (166 g N2O-N ha−1) or field pea (135 g N2O-N ha−1). Highest losses from canola were recorded during the growing season, whereas 75% of the annual N2O losses from the legumes occurred post-harvest. Legume N2-fixation provided 37–43% (chickpea), 54% (field pea) and 64% (faba bean) of total plant biomass N. Using only fixed-N inputs, we calculated EFs for chickpea (0.13–0.31%), field pea (0.18%) and faba bean (0.04%) that were significantly less than N-fertilised canola (0.48–0.78%) (P < 0.05), suggesting legume-fixed N is a less emissive form of N input to the soil than fertiliser N. Inputs of legume-fixed N should be more accurately quantified to properly gauge the potential for legumes to mitigate soil N2O emissions. EF’s from legume crops need to be revised and should include a factor for the proportion of the legume’s N derived from the atmosphere.
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The direct and indirect health effects of increasingly warmer temperatures are likely to further burden the already overcrowded hospital emergency departments (EDs). Using current trends and estimates in conjunction with future population growth and climate change scenarios, we show that the increased number of hot days in the future can have a considerable impact on EDs, adding to their workload and costs. The excess number of visits in 2030 is projected to range between 98–336 and 42–127 for younger and older groups, respectively. The excess costs in 2012–13 prices are estimated to range between AU$51,000–184,000 (0–64) and AU$27,000–84,000 (65+). By 2060, these estimates will increase to 229–2300 and 145–1188 at a cost of between AU$120,000–1,200,000 and AU$96,000–786,000 for the respective age groups. Improvements in climate change mitigation and adaptation measures are likely to generate synergistic health co-benefits and reduce the impact on frontline health services.
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This study compares Value-at-Risk (VaR) measures for Australian banks over a period that includes the Global Financial Crisis (GFC) to determine whether the methodology and parameter selection are important for capital adequacy holdings that will ultimately support a bank in a crisis period. VaR methodology promoted under Basel II was largely criticised during the GFC for its failure to capture downside risk. However, results from this study indicate that 1-year parametric and historical models produce better measures of VaR than models with longer time frames. VaR estimates produced using Monte Carlo simulations show a high percentage of violations but with lower average magnitude of a violation when they occur. VaR estimates produced by the ARMA GARCH model also show a relatively high percentage of violations, however, the average magnitude of a violation is quite low. Our findings support the design of the revised Basel II VaR methodology which has also been adopted under Basel III.
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Efficient and accurate geometric and material nonlinear analysis of the structures under ultimate loads is a backbone to the success of integrated analysis and design, performance-based design approach and progressive collapse analysis. This paper presents the advanced computational technique of a higher-order element formulation with the refined plastic hinge approach which can evaluate the concrete and steel-concrete structure prone to the nonlinear material effects (i.e. gradual yielding, full plasticity, strain-hardening effect when subjected to the interaction between axial and bending actions, and load redistribution) as well as the nonlinear geometric effects (i.e. second-order P-d effect and P-D effect, its associate strength and stiffness degradation). Further, this paper also presents the cross-section analysis useful to formulate the refined plastic hinge approach.
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A creative practice as research, UNDER THIS SKY is the latest investigation in a 12-year study into the “QMF Model”, an application of principles of community and cultural practice that generates large-scale, music spectacle events that derive their narrative and expression from the communities in which they are performed. UNDER THIS SKY is a large-scale musical specially commissioned for the city of Logan (Queensland) as the signature work of the 2015 Queensland Musical Festival. The investigation centres around the capacity of the “QMF Model” to engage with performers and musicians of Logan and then, through community consultation, create a narrative based on idiosyncratic stories and themes that would culminate in a performance event in August 2015. Previous creative projects, Boomtown (Gladstone), Behind the Cane (Bowen) and The Road We’re On (Charleville), were conducted in relatively small communities, Gladstone being the largest. In UNDER THIS SKY, the model is being tested in a large metropolitan city (Logan – 300,000). The core principles of CACD (community arts and cultural development) are being interrogated and adapted to fit this large-scale, whole of community environment. The purpose is to refine and further validate the “QMF Model” as a viable and effective process for community/artistic partnerships. Since February 2014, professional artists and managers have facilitated and shaped the work, up-skilling performers over a periods of 12 months, developing new relationships and creating opportunities for participation at all levels of experience. The research methodology involved creative practice through a continuous cycle of action, reflection, adaptation and application.
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Climate change is a major threat to global biodiversity, and its impacts can act synergistically to heighten the severity of other threats. Most research on projecting species range shifts under climate change has not been translated to informing priority management strategies on the ground. We develop a prioritization framework to assess strategies for managing threats to biodiversity under climate change and apply it to the management of invasive animal species across one-sixth of the Australian continent, the Lake Eyre Basin. We collected information from key stakeholders and experts on the impacts of invasive animals on 148 of the region's most threatened species and 11 potential strategies. Assisted by models of current distributions of threatened species and their projected distributions, experts estimated the cost, feasibility, and potential benefits of each strategy for improving the persistence of threatened species with and without climate change. We discover that the relative cost-effectiveness of invasive animal control strategies is robust to climate change, with the management of feral pigs being the highest priority for conserving threatened species overall. Complementary sets of strategies to protect as many threatened species as possible under limited budgets change when climate change is considered, with additional strategies required to avoid impending extinctions from the region. Overall, we find that the ranking of strategies by cost-effectiveness was relatively unaffected by including climate change into decision-making, even though the benefits of the strategies were lower. Future climate conditions and impacts on range shifts become most important to consider when designing comprehensive management plans for the control of invasive animals under limited budgets to maximize the number of threatened species that can be protected.
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High efficiency organic photovoltaic cells discussed in literature are normally restricted to devices fabricated on glass substrates. This is a consequence of the extreme brittleness and inflexibility of the commonly used transparent conductive oxide electrode, indium tin oxide (ITO). This shortcoming of ITO along with other concerns such as increasing scarcity of indium, migration of indium to organic layer, etc. makes it imperative to move away from ITO. Here we demonstrate a highly flexible Ag electrode that possesses low sheet resistances even in ultra-thin layers. It retains its conductivity under severe bending stresses where ITO fails completely. A P3HT:PCBM blend organic solar cell fabricated on this highly flexible electrode gives an efficiency of 2.3%.
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This week, Sotheby's sold the late Clifford Possum Tjapaltjarri's painting, Warlugulong. The auction-house's spokesman, Tim Klingender, was enthusiastic about the high price commanded by the art work: "The painting was a really great painting and it deserved to make a really fantastic price, and it made that price."
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Fair Use Week has been celebrated this week in the United States, with great gusto and enthusiasm. At Harvard Library, Kyle Courtney commented: ‘Fair use is critical and important to innovation, scholarship and research in the United States.’ Kenneth Crews emphasized that ‘the new technological ventures, like other creative pursuits, require fair use and other copyright limitations for experimentation and success.’ Legal director Corynne McSherry of the Electronic Frontier Foundation has highlighted the significance and the importance of the defence of fair use: ‘Fair use provides breathing space in copyright law, making sure that control of the right to copy and distribute doesn’t become control of the right to create and innovate.’ For Techdirt, Mike Masnick has emphasized that fair use is a right – and not an exception or a mere defence. Peter Jaszi and Pat Aufderheide have highlighted the contextual operation of fair use in particular artistic communities. Molly Van Houweling of the Authors Alliance has written about the ecstasy of influence – the role of inspiration and appropriation in all acts of artistic creation. Fair use has been celebrated as a many-splendored legal creation.
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Engineers and asset managers must often make decisions on how to best allocate limited resources amongst different interrelated activities, including repair, renewal, inspection, and procurement of new assets. The presence of project interdependencies and the lack of sufficient information on the true value of an activity often produce complex problems and leave the decision maker guessing about the quality and robustness of their decision. In this paper, a decision support framework for uncertain interrelated activities is presented. The framework employs a methodology for multi-criteria ranking in the presence of uncertainty, detailing the effect that uncertain valuations may have on the priority of a particular activity. The framework employs employing semi-quantitative risk measures that can be tailored to an organisation and enable a transparent and simple-to-use uncertainty specification by the decision maker. The framework is then demonstrated on a real world project set from a major Australian utility provider.
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An improved understanding of the characteristics of the pre-discharge current pulses in GIS will lead to improved analyses of the results from the UHF partial discharge detection method. This paper presents the characteristics of the first pre-discharge current pulses from a point-to-plain geometry at 1 bar absolute under both polarities of a 1.1/80 us lightning impulse. The analysis has shown that the pre-discharge current wave shape, peak current magnitude and charge is effected by the instantaneous voltage at which the pre- discharge took place as well as the polarity of the active electrode. The measured results show that protrusions on the electrodes have slower wave shape parameters than those reported for free conducting particles.
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This paper presents preliminary results of an investigation into the detection of partial discharges on the rise of impulse voltages from a point-to-plane gap in SF6. A parallel RC detection impedance is placed in the earth path of a point. Computer simulations are done to determine the values of R and C that will result in the smallest impulse voltage signal and the largest discharge signal across the detection impedance. These simulations and the experimental work show that the impulse voltage signal can not be sufficiently attenuated during the rise time of the applied voltage impulse using the RC detection impedance alone. An alternative discharge detection method is proposed in which a resonant partial discharge coupler is used. Elimination of noise and the impulse voltage signal can be achieved by shorting the coupler plate to the ground plane in the middle of the disk. However, due to the bandwidth of the measuring equipment and noise from the impulse generator it was not possible to detect discharges on the rising edge of a 1.5s voltage impulse using a coupler shorted in the middle. It was found that for this particular coupler, with no shorting points, and if the rising edge of the voltage impulse is longer than 5us, (10us) PD activity can be detected on the rising edge.