7 resultados para Cohesive zone model

em Deakin Research Online - Australia


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Assessing patterns of fisheries activity at a scale related to resource exploitation has received particular attention in recent times. However, acquiring data about the distribution and spatiotemporal allocation of catch and fishing effort in small scale benthic fisheries remains challenging. Here, we used GIS-based spatio-statistical models to investigate the footprint of commercial diving events on blacklip abalone (Haliotis rubra) stocks along the south-west coast of Victoria, Australia from 2008 to 2011. Using abalone catch data matched with GPS location we found catch per unit of fishing effort (CPUE) was not uniformly spatially and temporally distributed across the study area. Spatial autocorrelation and hotspot analysis revealed significant spatiotemporal clusters of CPUE (with distance thresholds of 100's of meters) among years, indicating the presence of CPUE hotspots focused on specific reefs. Cumulative hotspot maps indicated that certain reef complexes were consistently targeted across years but with varying intensity, however often a relatively small proportion of the full reef extent was targeted. Integrating CPUE with remotely-sensed light detection and ranging (LiDAR) derived bathymetry data using generalized additive mixed model corroborated that fishing pressure primarily coincided with shallow, rugose and complex components of reef structures. This study demonstrates that a geospatial approach is efficient in detecting patterns and trends in commercial fishing effort and its association with seafloor characteristics.

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For over two decades the issue of East Timor's right to self-determination has been a ‘prickly’ issue in Australian foreign policy. The invasion by Indonesian forces in 1975 was expected, as Australian policy-makers had been well informed of the events leading up to the punitive action being taken. Indeed, prior discussions involving the future of the territory were held between the Australian Prime Minister and the Indonesian President in 1974. In response to the events unfolding in the territory the Australian Labor Government at the time was presented with two policy options for dealing with the issue. The Department of Defence recommended the recognition of an independent East Timor; whereas the Department of Foreign Affairs proposed that Australia disengage itself as far as possible from the issue. The decision had ramifications for future policy considerations especially with changes in government. With the Department of Foreign Affairs option being the prevailing policy what were the essential ingredients that give explanation for the government's choice? It is important to note the existence of the continuity and cyclical nature of attitudes by Labor governments toward Indonesia before and after the invasion. To do so requires an analysis of the influence ‘Doc’ Evatt had in shaping any possible Labor tradition in foreign policy articulation. The support given by Evatt for the decolonisation of the Netherlands East Indies (Indonesia) gave rise to the development of a special relationship-so defined. Evidence of the effect Evatt had on future Labor governments may be found in the opinions of Gough Whitlam. In 1975 when he was Prime Minister, Whitlam felt the East Timor issue was merely the finalisation of Indonesia's decolonisation honouring Evatt's long held anti-colonialist tradition existing in the Australian Labor Party. The early predisposition toward Indonesia's cohesiveness surfaced again in the Hawke and Keating Labor governments of later years. It did not vary a great deal with changes in government The on-going commitment to preserving and strengthening the bilateral relationship meant Indonesia's territorial integrity became the focus of the Australian political elites’ regional foreign policy determinations. The actions taken by policy-makers served to promote the desire for a stable region ahead of independence claims of the East Timorese. From a realist perspective, the security dilemma for Australian policy-makers was how to best promote regional order and stability in the South East Asian region. The desire for regional cohesiveness and stability continues to drive Australian political elites to promote policies that gives a priority to the territorial integrity of regional states. Indonesia, in spite of its diversity, was only ever thought of as a cohesive unitary state and changes to its construct have rarely been countenanced. Australia's political elite justifications for this stance vacillate between strategic and economic considerations, ideological (anti-colonialism) to one of being a pragmatic response to international politics. The political elite argues the projection of power into the region is in Australia’s national interest. The policies from one government to the next necessarily see the national interest as being an apparent fixed feature of foreign policy. The persistent fear of invasion from the north traditionally motivated Australia's political elite to adopt a strategic realist policy that sought to ‘shore up’ the stability, strength and unity of Indonesia. The national interest was deemed to be at risk if support for East Timorese independence was given. The national interest though can involve more than just the security issue, and the political elite when dealing with East Timor assumed that they were acting in the common good. Questions that need to be addressed include determining what is the national interest in this context? What is the effect of a government invoking the national interest in debates over issues in foreign policy? And, who should participate in the debate? In an effort to answer these questions an analysis of how the ex-foreign affairs mandarin Richard Woolcott defines the national interest becomes crucial. Clearly, conflict in East Timor did have implications for the national interest. The invasion of East Timor by Indonesia had the potential to damage the relationship, but equally communist successes in 1975 in Indo-China raised Australia's regional security concerns. During the Cold War, the linking of communism to nationalism was driving the decision-making processes of the Australian policy-makers striving to come to grips with the strategic realities of a changing region. Because of this, did the constraints of world politics dominated by Cold War realities combined with domestic political disruption have anything to do with Australia's response? Certainly, Australia itself was experiencing a constitutional crisis in late 1975. The Senate had blocked supply and the Labor Government did not have the funds to govern. The Governor-General by dismissing the Labor Government finally resolved the impasse. What were the reactions of the two men charged with the responsibility of forming the caretaker government toward Indonesia's military action? And, could the crisis have prevented the Australian government from making a different response to the invasion? Importantly, and in terms of economic security, did the knowledge of oil and gas deposits thought to exist in the Timor Sea influence Australia's foreign policy? The search for oil and gas requires a stable political environment in which to operate. Therefore for exploration to continue in the Timor Sea Australia must have had a preferred political option and thoughts of with whom they preferred to negotiate. What was the extent of each government's cooperation and intervention in the oil and gas industry and could any involvement have influenced the Australian political elites’ attitude toward the prospect of an independent East Timor? Australia's subsequent de jure recognition that East Timor was part of Indonesia paved the way for the Timor Gap (Zone of Cooperation) Treaty signing in 1989. The signing underpinned Australia's acceptance of Indonesian sovereignty over East Timor. The outcome of the analysis of the issues that shaped Australia's foreign policy toward East Timor showed that the political elite became locked into an integration model, which was defended by successive governments. Moreover, they formed an almost reflexive defence of Indonesia both at the domestic and international level.

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This paper applies dimensional analysis to propose an alternative model for estimating the effective density of flocs (Δρf). The model takes into account the effective density of the primary particles, in addition to the sizes of the floc and primary particles, and does not consider the concept of self-similarity. The model contains three dimensionless products and two empirical parameters (αf and βf), which were calibrated by using data available in the literature. Values of αf=0.7 and βf=0.8 were obtained. The average value of the primary particle size (Dp) for the data used in the analysis, inferred from the new model, was found to vary from 0.05 μm to 100 μm with a mean value of 2.5 μm. Good comparisons were obtained in comparing the estimated floc-settling velocity on the basis of the proposed model for effective floc density with the measured value.

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Through analysis of the dynamics between science and decision-making, we argue that diagnosing fit-for purpose approaches to linking science and decision-making may be possible. Such diagnosis should enable identification of appropriate processes, institutions, objects (e.g. tools, information products) and relationships that can facilitate outcomes. We begin the paper by unsettling the traditional constructions that science must distance itself from debates about values and what is at stake, and so from policy making. Then, drawing from mixed methods case studies in coastal South-eastern Australia, we describe how scientific research has had a bearing on decisions affecting society and the environment. These analyses suggest that the willingness and capacity of research organisations, programmes or projects to actively reflect on and participate in the evolution of the 'operating environment' for their research is integral to their ability to inform outcomes through science. © 2014 Elsevier Ltd.

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Energy efficiency of a building has become a major requirement since the building sector produces 40%-50% of the global greenhouse gas emissions. This can be achieved by improving building’s performance through energy savings, by adopting energy efficient technologies and reducing CO2 emissions. There exist several technologies with less or no environmental impact that can be used to reduce energy consumption of the buildings. Earth pipe cooling system is one of them, which works with a long buried pipe with one end for intake air and the other end for providing air cooled by soil to the building. It is an approach for cooling a room in a passive process without using any habitual mechanical unit. The paper investigates the thermal performance of a horizontal earth pipe cooling system in a hot and humid subtropical climatic zone in Queensland, Australia. An integrated numerical model for the horizontal earth pipe cooling system and the room (or building) was developed using ANSYS Fluent to measure the thermal performance of the system. The impact of air temperature, soil temperature, air velocity and relative humidity on room cooling performance has also been assessed. As the soil temperature was below the outdoor minimum temperature during the peak warming hours of the day, it worked as an effective heat sink to cool the room. Both experimental and numerical results showed a temperature reduction of 1.11oC in the room utilizing horizontal earth pipe cooling system which will assist to save the energy cost in the buildings.

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The complex architecture of many fibre-reinforced composites makes the generation of finite element meshes a labour-intensive process. The embedded element method, which allows the matrix and fibre reinforcement to be meshed separately, offers a computationally efficient approach to reduce the time and cost of meshing. In this paper we present a new approach of introducing cohesive elements into the matrix domain to enable the prediction of matrix cracking using the embedded element method. To validate this approach, experiments were carried out using a modified Double Cantilever Beam with ply drops, with the results being compared with model predictions. Crack deflection was observed at the ply drop region, due to the differences in stiffness, strength and toughness at the bi-material interface. The new modelling technique yields accurate predictions of the failure process in composites, including fracture loads and crack deflection path.