968 resultados para GREAT BARRIER REEF
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Portable water-filled barriers (PWFBs) are roadside appurtenances that are used to prevent errant vehicles from penetrating into temporary construction zones on roadways. A numerical model of the composite PWFB, consisting of a plastic shell, steel frame, water and foam was developed and validated against results from full scale experimental tests. This model can be extended to larger scale impact cases, specifically ones that include actual vehicle models. The cost-benefit of having a validated numerical model is significant and this allows the road barrier designer to conduct extensive tests via numerical simulations prior to standard impact tests Effects of foam cladding as additional energy absorption material in the PWFB was investigated. Different types of foam were treated and it was found that XPS foam was the most suitable foam type. Results from this study will aid PWFB designers in developing new generation of roadside structures which will provide enhanced road safety.
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Portable water-filled barriers (PWFBs) are roadside appurtenances that prevent vehicles from penetrating into temporary construction zones on roadways. PWFBs are required to satisfy the strict regulations for vehicle re-direction in tests. However, many of the current PWFBs fail to re-direct the vehicle at high speeds due to the inability of the joints to provide appropriate stiffness. The joint mechanism hence plays a crucial role in the performance of a PWFB system at high speed impacts. This paper investigates the desired features of the joint mechanism in a PWFB system that can re-direct vehicles at high speeds, while limiting the lateral displacement to acceptable limits. A rectangular “wall” representative of a 30 m long barrier system was modeled and a novel method of joining adjacent road barriers was introduced through appropriate pin-joint connections. The impact response of the barrier “wall” and the vehicle was obtained and the results show that a rotational stiffness of 3000 kNm/rad at the joints seems to provide the desired features of the PWFB system to re-direct impacting vehicles and restrict the lateral deflection. These research findings will be useful to safety engineers and road barrier designers in developing a new generation of PWFBs for increased road safety.
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Review of Patrick Leigh Fermor : An Adventure by Artemis Cooper (John Murray, 2012).
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In large sedimentary basins with layers of different rocks, the groundwater flow between aquifers depends on the hydraulic conductivity (K) of the separating low-permeable rocks, or aquitards. Three methods were developed to evaluate K in aquitards for areas with limited field data: • Coherence and harmonic analysis: estimates the regional-scale K based on water-level fluctuations in adjacent aquifers. • Cokriging and Bayes' rule: infers K from downhole geophysical logs. • Fluvial process model: reproduces the lithology architecture of sediment formations which can be converted to K. These proposed methods enable good estimates of K and better planning of further drillholes.
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There are currently more than 700 cities operating bike share programs. Purported benefits of bike share include flexible mobility, physical activity, reduced congestion, emissions and fuel use. Implicit or explicit in the calculation of program benefits are assumptions regarding the modes of travel replaced by bike share journeys. This paper examines the degree to which car trips are replaced by bike share, through an examination of survey and trip data from bike share programs in Melbourne, Brisbane, Washington, D.C., London, and Minneapolis/St. Paul. A secondary and unique component of this analysis examines motor vehicle support services required for bike share fleet rebalancing and maintenance. These two components are then combined to estimate bike share’s overall contribution to changes in vehicle kilometers traveled. The results indicate an estimated reduction in motor vehicle use due to bike share of approx. 90,000 km per annum in Melbourne and Minneapolis/St. Paul and 243,291 km for Washington, D.C. London’s bike share program however recorded an additional 766,341 km in motor vehicle use. This was largely due to a low car mode substitution rate and substantial truck use for rebalancing of bicycles. As bike share programs mature, evaluation of their effectiveness in reducing car use may become increasingly important. Researchers can adapt the analytical approach proposed in this paper to assist in the evaluation of current and future bike share programs.
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The Ar/O2plasma needle in the induction of A549 cancer cells apoptosis process is studied by means of real-time observation. The entire process of programmed cell death is observed. The typical morphological changes of A549 apoptosis are detected by 4′, 6-diamidino-2-phenylindole staining, for example, chromatin condensation and nuclear fragmentation. Cell viability is determined and quantified by neutral red uptake assay, and the survival rate of A549 from Ar/O2plasmas is presented. Further spectral analysis indicates the reactive species, including O and OH play crucial roles in the cell inactivation.
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Introduction and Aims. The contextual and temporal factors of post-school celebratory events ('Schoolies') place young people at elevated risk of excessive drinking compared with other social occasions. This study investigates the impact of an applied theatre prevention program 'Choices' in reducing the risk of drinking and other risk behaviours during Schoolies celebrations. Design and Methods. Choices was delivered in the last term of Year 12 across 28 North Queensland schools. A total of 352 school leavers (43.1% male, mean age=17.14years) completed a questionnaire at Whitsunday Schoolies, Queensland, Australia on 23-24 November 2010. Nearly 49% of respondents had attended Choices. The survey included measures of alcohol use, illicit drug use and associated problems during Schoolies and a month prior to Schoolies. Results. After controlling for gender and pre-Schoolies drinking, school leavers who attended Choices were significantly less likely to report illicit drug use (OR=0.51, P<0.05) and problem behaviours (OR=0.40, P<0.01) than those who did not attend Choices. There was, however, no intervention effect in risky drinking (i.e. drank on 5 or more days, typical amount five or more standard drink and binge drank on 3 or more days) at Schoolies (OR=0.92, P=0.80). Discussion and Conclusions. Delivery of a youth-specific applied theatre prevention program employing a harm minimisation framework may be effective in reducing high-risk behaviours associated with alcohol consumption at celebratory events, even if young people expect to engage in excessive alcohol consumption. [Quek L-H, White A, Low C, Brown J, Dalton N, Dow D, Connor JP. Good choices, great future: An applied theatre prevention program to reduce alcohol-related risky behaviours during Schoolies. Drug Alcohol Rev 2012;31:897–902]
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A travel article about Halifax, Nova Scotia. MOTORISTS in Nova Scotia are so polite it's almost a shame to leave, writes Kari Gislason. By the end of my second day in Halifax, I begin to develop deep concerns about the safety of the locals, or the Haligonians as they're known. I wonder how they ever leave their fair city or, perhaps more to the point, how they ever make it back...
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Part of the Next Wave MEMBRANE Project, Great Expectations draws attention to the parallels between our expectations of art and new technology to make the world a better place. The theme of the 2008 Next Wave Festival, ‘Closer Together’, refers to the way society is ― for the better or for the worse ― becoming increasingly connected by media and communication technologies. Sceptical of the acclaimed social achievements of new technologies, Boxcopy: Contemporary Art Space, a Brisbane-based artist-run initiative, explores the futility of human activities, including art production and consumption, with a collection of works created by young and emerging Brisbane artists. Works for this project include: Early machines such as the Commodore 64 were tape-based, and hence had their games distributed on ordinary cassettes (2009) by Tim Kerr & Extra Features (2008) by Tim Woodward; Spine (2008), Joseph Briekers; Whiteout (2008), Channon Goodwin; Explosive Revelations (2008), Daniel McKewen.
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Schottky barrier solar cells based on graphene/n-silicon heterojunction have been fabricated and characterized and the effect of graphene molecular doping by HNO3 on the solar cells performances have been analyzed. Different doping conditions and thermal annealing processes have been tested to asses and optimize the stability of the devices. The PCE of the cells increases after the treatment by HNO3 and reaches 5% in devices treated at 200 °C immediately before the exposition to the oxidant. Up to now our devices retain about 80% of efficiency over a period of two weeks, which represents a good stability result for similar devices.
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1.Marine ecosystems provide critically important goods and services to society, and hence their accelerated degradation underpins an urgent need to take rapid, ambitious and informed decisions regarding their conservation and management. 2.The capacity, however, to generate the detailed field data required to inform conservation planning at appropriate scales is limited by time and resource consuming methods for collecting and analysing field data at the large scales required. 3.The ‘Catlin Seaview Survey’, described here, introduces a novel framework for large-scale monitoring of coral reefs using high-definition underwater imagery collected using customized underwater vehicles in combination with computer vision and machine learning. This enables quantitative and geo-referenced outputs of coral reef features such as habitat types, benthic composition, and structural complexity (rugosity) to be generated across multiple kilometre-scale transects with a spatial resolution ranging from 2 to 6 m2. 4.The novel application of technology described here has enormous potential to contribute to our understanding of coral reefs and associated impacts by underpinning management decisions with kilometre-scale measurements of reef health. 5.Imagery datasets from an initial survey of 500 km of seascape are freely available through an online tool called the Catlin Global Reef Record. Outputs from the image analysis using the technologies described here will be updated on the online repository as work progresses on each dataset. 6.Case studies illustrate the utility of outputs as well as their potential to link to information from remote sensing. The potential implications of the innovative technologies on marine resource management and conservation are also discussed, along with the accuracy and efficiency of the methodologies deployed.
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Understanding the natural variability of the Earth's climate system and accurately identifying potential anthropogenic influences requires long term, geographically distributed records of key climate indicators, such as temperature and precipitation that extend prior to the last 400. years of the Holocene. Reef corals provide an excellent source of high resolution climate records, and importantly represent the tropical marine environment where palaeoclimate data are urgently required. Recent decades have seen significant improvement in our understanding of coral biomineralisation, the associated uptake of geochemical proxies and methods of identifying and understanding the effects of both early and late, post depositional diagenetic alteration. These processes all have significant implications for interpreting geochemical proxies relevant to palaeoclimatic reconstructions. This paper reviews the current 'state of the art' in terms of coral based palaeoclimate reconstructions and highlights a key remaining problem. The majority of coral based palaeoclimate research has been derived from massive colonies of Porites. However, massive Porites are not globally abundant and may not provide material of a particular age of interest in those regions where they are present. Therefore, there is great potential for alternate coral genera to act as complimentary climate archives. While it remains critical to consider five key factors - vital effects, differential growth morphologies, geochemical heterogeneity in the skeletal ultrastructure, transfer equation selection and diagenetic screening of skeletal material - in order to allow the highest level of accuracy in coral palaeoclimate reconstructions, it is also important to develop alternate taxa for palaeoclimate studies in regions where Porites colonies are absent or rare. Currently as many as nine genera other than Porites have proven at least limited utility in palaeothermometry, most of which are found in the Atlantic/Caribbean region where massive Porites do not exist. Even branching taxa such as Acropora have significant potential to preserve environmental archives. Increasing this capability will greatly expand the number of potential geochemical archives available for longer term temporal records of palaeoclimate.
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Curriculum is always in a state of flux and so often the moves to ‘reform’ it are political rather than pedagogical. So often in these days of accountability we focus on the learner. I want to focus on the teacher in this presentation. As English educators we have to ‘fit’ whatever new policy model comes our way. The Australian curriculum seems to have tried to please every stakeholder in its process and as such has been formed without a single, unifying coherent theoretical basis. How do we challenge this paper tiger? We have to find the pedagogical models within the current framework and see what still works in practice. At the chalk-face there are still teaching, learning and assessment practices in English surviving from the last few decades of pedagogical change; and there is also room for accommodating new practices. Embracing and adapting the old and the new may be the key to staying creative and passionately engaged with our subject area.
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In the last few decades payday loans have mushroomed in many developed countries. The arguments for and against an industry which provides small, short-term loans at very high interest rates have also blossomed. This article presents findings from an Australian study to contribute to the international policy and practice debate about a sector which orients to those on a low income. At the heart of this debate lies a conundrum: Borrowing from payday lenders exacerbates poverty, yet many low-income households rely on these loans. We argue that the key problem is the restricted framework within which the debate currently oscillates.