37 resultados para Expanded clay

em Deakin Research Online - Australia


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While research has focussed on the current and potential role of the practice nurse (PN) in Australia, the acceptability of this role by consumers has not been investigated. In 2002, two independent studies were carried out into consumer perceptions of PNs. A discussion between the two groups of researchers at the inaugural National Practice Nurse Conference in 2003, identified significant similarities in the findings of these studies. This article reports the combined findings as they relate to consumers' desire for access to the health practitioner of their choice, and their concern that PNs may assume a gatekeeping role. These perceptions may have significant impact on the acceptance of PNs across Australia.

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Although much research has been done on the existence and formation of risk and issue based health policies, there is only little insight in health policy development processes in a broader context. This hampers intervention in these policy processes to adequately develop integrated and effective health policies.

Legislation in the Netherlands requires municipalities to develop and implement local health policies. These policies are supposed to aim at the promotion of health across sectors and with a strong community involvement. Health policy development processes have been studied in four Dutch municipalities. For each case, we identified a range of stakeholders and monitored the change or stability of their characteristics over 3 years. In addition, for each case, three overlaying maps of networks were made addressing communication and collaboration actions within the defined set of stakeholders. We point out a number of barriers which impede integrated policy development at the local level: the importance given to local health policy, the medical approach to health development, the organizational self-interest rather than public health concern, the absence of policy entrepreneurial activity.

Furthermore, this article advocates the use of complementary theoretical frameworks and the expansion of the methodological toolbox for health promotion. The value of stakeholder and network analysis in the health promotion domain, at this stage, is two-fold. First, mapping relevant actors, their positions and connections in networks provides us with insight into their capacity to participate and contribute to health policy development. Second, these new tools contribute to a further understanding of policy entrepreneurial roles to be taken up by health promotion professionals and health authorities in favour of the socio-environmental approach to health.

Notwithstanding the value of this first step, more research is required into both the practical application as well as in the theoretical connections with, for example, Multiple Streams theory.


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Copper is an important micronutrient and trace amounts are essential for crop growth. However, high concentrations of copper will produce toxic effects. Australia is increasingly developing production of crops in water repellent soils. Clay amendment, a common amelioration techniques used in Australia, has demonstrated agronomic benefits in increased crop or pasture production. The sorption and desorption of copper and the effect of clay treatment on copper behaviour in a water repellent soil collected from an experimental farm in South Australia is studied. We found that the water repellent soils amended with clay have an increased adsorption capacity of copper. Also the clay-amended soils had an increased ratio of specific sorption to total sorption of copper. The implications of this study to the sustainable agro-environmental management of water repellent soils is discussed.

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Little attention has been paid to the possibility that soil water repellency could enhance non-equilibrium water flow and solute transport through macropores present in structured clay soils. In this study, we measured infiltration and solute transport in a clay soil under near-saturated conditions in both the field using tension infiltrometers and in the laboratory on undisturbed soil columns. Measurements were made on adjacent plots under grass and continuous arable cultivation. Steady-state field infiltration rates measured using water and ethanol as the infiltrating fluids demonstrated that the soil macroporosity under grass was better developed, but that much of the structural pore system was inactive due to water repellency. No water repellency was detected on the arable plot disturbed by tillage. Dye tracing showed that the conducting macroporosity was largely comprised of earthworm channels in the grassed plot and inter-aggregate voids resulting from ploughing in the arable plot. Tracer breakthrough curves measured on field-dry soil indicated rapid macropore transport in columns taken from both plots, although the degree of non-equilibrium transport appeared somewhat stronger under grass. This result, which was attributed to water repellency, was also consistent with the larger flow-weighted mean pore size found in the field infiltration experiments. It is concluded that water repellency in undisturbed structured clay soils can have significant effects on the occurrence of non-equilibrium water and solute transport in macropores.

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Naarah Sawers is an Alfred Deakin Post-Doctoral Research Fellow at Deakin University where she is researching environmental agendas in computer games for children. She has also published and researched in children's literature in the area of feminist bio-ethics and agency.

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3-screen film performance constituted from hand drawn direct-on-film imagery and scratched soundtracks that are further manipulated through the performance to comment and respond on the position accorded such marginal work, namely its complete erasure and marginalization within critical debate in Australia, and to further lay bare the processes of image manipulation.

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Summary: This article discusses research that explored an alternative to proceduralized child protection practice informed by the risk paradigm, by expanding the repertoire available to practitioners through combining features of the risk paradigm with social constructionism. This approach incorporates three dimensions: theories of knowledge and power, related professional roles, and practice skills. In this article, we discuss and critically evaluate only the first dimension: theories of knowledge and power. Through dialogue facilitated by semi-structured questions, we explored practitioners' perspectives about the relevance and appropriateness of the alternative approach for practice.

Findings: The practitioners' participation and feedback offer insights into complex connections between `theory' and `practice' with the practitioner as a positioned subject and mediator of practical meanings of formal concepts.

Applications:
1) Recognition of each practitioner's interpretation of formal concepts and how they are applied in actual practice, even within shared organizational contexts. 2) The importance of dialogue to expand the range of possibilities that maintain openness to ongoing learning. 3) The value of theoretical pluralism that may offer greater opportunities for professional discretion, rather than single self-contained approaches that may constrain effective and ethical practice.

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Paleo Lake Bungunnia covered more than 40 000 km2 of southern Australia during the Plio-Pleistocene, although the age and origin of the lake remain controversial. The Blanchetown Clay is the main depositional unit and outcrop at Nampoo Station in far-western New South Wales provides the most continuous lacustrine section preserved in the basin. Here the Blanchetown Clay represents the maximum lake fill and comprises: (i) a basal well-sorted sand with interbedded clay (Chowilla Sand), representing initial flooding at the time of lake formation; (ii) a thick sequence of green-grey clay comprised dominantly of kaolinite and illite, with the apparently cyclic occurrence of illite interpreted to represent cool and dry glacial climatic intervals; and (iii) a 2.6 m-thick sequence of finely laminated silt and silty clay, here defined as the Nampoo Member of the Blanchetown Clay. New magnetostratigraphic data constrain the age of the oldest lake sediments to be younger than 2.581 Ma (Matuyama-Gauss boundary) and probably as young as 2.4 Ma. This age is significantly younger than the age of 3.2 Ma previously suggested for lake formation. The youngest Blanchetown Clay is older than 0.781 Ma (Brunhes-Matuyama boundary) and probably as old as 1.2 Ma. The Nampoo Station section provides a framework for the construction of a regional Plio-Pleistocene stratigraphy in the Murray Basin.

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The salt attack of Fired Clay Bricks (FCBs) causes surface damage that is aesthetically displeasing and eventually leads to structural damage. Methods for determining the resistances of FCBs to salt weathering have mainly tried to simulate the process by using accelerating aging tests. Most research in this area has concentrated on the types of salt that can cause damage and the damage that occurs during accelerated aging tests. This approach has lead to the use of accelerated aging tests as standard methods for determining resistance. Recently, it has been acknowledged that are not the most reliable way to determine salt attack resistance for all FCBs in all environments. Few researchers have examined FCBs with the aim of determining which material and mechanical properties make a FCB resistant to salt attack. The aim of this study was to identify the properties that were significant to the resistance of FCBs to salt attack. In doing so, this study aids in the development of a better test method to assess the resistance of FCBs to salt attack. The current Australian Standard accelerated aging test was used to measure the resistance of eight FCBs to salt attack using sodium sulfate and sodium chloride. The results of these tests were compared to the water absorption properties and the total porosity of FCBs. An empirical relationship was developed between the twenty-four-hour water absorption value and the number of cycles to failure from sodium sulfate tests. The volume of sodium chloride solution was found to be proportional to the total porosity of FCBs in this study. A phenomenological discussion of results led to a new mechanism being presented to explain the derivation of stress during salt crystallisation of anhydrous and hydratable salts. The mechanical properties of FCBs were measured using compression tests. FCBs were analysed as cellular materials to find that the elastic modules of FCBs was equivalent for extruded FCBs that had been fired a similar temperatures and time. Two samples were found to have significantly different elastic moduli of the solid microstructure. One of these samples was a pressed brick that was stiffer due to the extra bond that is obtained during sintering a closely packed structure. The other sample was an extruded brick that had more firing temperature and time compared with the other samples in this study. A non-destructive method was used to measure the indentation hardness and indentation stress-strain properties of FCBs. The indentation hardness of FCBs was found to be proportional to the uniaxial compression strength. In addition, the indentation hardness had a better linear correlation to the total porosity of FCBs except for those samples that had different elastic moduli of the solid microstructure. Fractography of exfoliated particles during salt cycle tests and compression tests showed there was a similar pattern of fracture during each failure. The results indicate there were inherent properties of a FCB that determines the size and shape of fractured particles during salt attack. The microstructural variables that determined the fracture properties of FCBs were shown to be important variables to include in future models that attempt to estimate the resistance of FCBs to salt attack.

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This paper investigates the effect of both the mixing technique and heating rate during cure on the dispersion of montmorillonite (MMT) clay in an epoxy resin. The combination of sonication and using a 10. °C/min heating rate during cure was found to facilitate the dispersion of nanoclay in epoxy resin. These processing conditions provided a synergistic effect, making it possible for polymer chains to penetrate in-between clay galleries and detach platelets from their agglomerates. As the degree of dispersion was enhanced, the flexural modulus and strength properties were found to decrease by 15% and 40%, respectively. This is thought to be due to individual platelets fracturing in the nanocomposite. Complementary techniques including X-ray diffraction (XRD), small angle X-ray scattering (SAXS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) and optical microscopy were essential to fully characterise localised and spatial regions of the clay morphologies.

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