985 resultados para pre-filtration vertical columns
Resumo:
An integrated approach to assessment afforded pre-service teachers the opportunity to learn about a local sustainability issue through three learning areas: science and technology,the arts and studies of society and environment (SOSE). Three sustainability issues chosen by the pre-service teachers are presented in this paper highlighting the science concepts explored. Affordances and constraints of the integrated task are discussed in the conclusion.
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Australia is a multicultural immigrant society created by public policy and direct state action over a period of two hundred years. It is now one of the world’s most diverse societies. However, like many nations, Australia faces challenges to managing ‘unauthorized arrivals’ who claim to be refugees. The issue of how to deal with unauthorized arrivals is controversial and highly emotive as it challenges public policy and government capacity to manage the multicultural ‘mix’ of Australia’s population. It also raises questions about border security. Given that it is impossible to discern beforehand who is a ‘proper’ refugee and who is not, claims to refugee status by unauthorised arrivals in Australia need to be tested against international convention criteria devised by the United Nations High Commissioner for Refugees (UNHCR). There are no simple solutions to controversial questions such as how and where should unauthorised arrivals, and the children accompanying them, be housed whilst their claims are investigated? Moreover, as this issue continues to prompt division and heated debate in Australian society, teachers new to the profession are often reluctant to explore it in the classroom. However, there are opportunities in national and state curriculum documents for the values dimensions of curriculum inquiries into controversial issues such as this to be addressed. For example, the most recent national statement on the goals for schooling in Australia, the Melbourne Declaration (MCEETYA, 2008), makes clear that Australian students need to be prepared for the challenges of the 21st century and to develop the capacity for innovation and complex problem-solving. The Melbourne Declaration informs the first national curriculum to be implemented in the Australian states and territories, and all other national and state initiatives. Its focus on developing active and informed citizens who can contribute to a socially cohesive society implies a capacity to deal with a range of issues associated with cultural diversity, This chapter explores the ways in which pre-service and early career teachers in one Australian state reflect upon curriculum opportunities to address controversial issues in the social sciences and history classroom. As part of their pre-service education, all the participants in this study completed a final year social science curriculum method unit that embedded a range of controversial issues, including the placement of children in Australian Immigration Detention Centres (IDCs), for investigation. By drawing from interviews and focus groups conducted with different cohorts of pre-service teachers in their final year of university study and beginning years of teaching, this chapter analyses the range of perceptions about how controversial issues can be examined in the secondary classroom as part of fostering informed citizenship. The discussion and analysis of the qualitative data in this study makes no claims for the representativeness of its findings, rather, a range of beginner teacher insights into a complex and important facet of teaching in a period of change and uncertainty is offered.
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Most of the existing algorithms for approximate Bayesian computation (ABC) assume that it is feasible to simulate pseudo-data from the model at each iteration. However, the computational cost of these simulations can be prohibitive for high dimensional data. An important example is the Potts model, which is commonly used in image analysis. Images encountered in real world applications can have millions of pixels, therefore scalability is a major concern. We apply ABC with a synthetic likelihood to the hidden Potts model with additive Gaussian noise. Using a pre-processing step, we fit a binding function to model the relationship between the model parameters and the synthetic likelihood parameters. Our numerical experiments demonstrate that the precomputed binding function dramatically improves the scalability of ABC, reducing the average runtime required for model fitting from 71 hours to only 7 minutes. We also illustrate the method by estimating the smoothing parameter for remotely sensed satellite imagery. Without precomputation, Bayesian inference is impractical for datasets of that scale.
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A common finding in brand extension literature is that extension’s favorability is a function of the perceived fit between the parent brand and its extension (Aaker and Keller 1990; Park, Milberg, and Lawson 1991; Volckner and Sattler 2006) that is partially mediated by perceptions of risk (Milberg, Sinn, and Goodstein 2010; Smith and Andrews 1995). In other words, as fit between the parent brand and its extension increases, parent brand beliefs become more readily available, thus increasing consumer certainty and confidence about the new extension, which results in more positive evaluations. On the other hand, as perceived fit decreases, consumer certainty about the parent brand’s ability to introduce the extension is reduced, leading to more negative evaluations. Building on the notion that perceived fit of vertical line extensions is a function of the price/quality distance between parent brand and its extension (Lei, de Ruyter, and Wetzels 2008), traditional brand extension knowledge predicts a directionally consistent impact of perceived fit on evaluations of vertical extensions. Hence, vertical (upscale or downscale) extensions that are placed closer to the parent brand in the price/quality spectrum should lead to higher favorability ratings compared to more distant ones.
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Background: Conventional biodiesel production relies on trans-esterification of lipids extracted from vegetable crops. However, the use of valuable vegetable food stocks as raw material for biodiesel production makes it an unfeasibly expensive process. Used cooking oil is a finite resource and requires extra downstream processing, which affects the amount of biodiesel that can be produced and the economics of the process. Lipids extracted from microalgae are considered an alternative raw material for biodiesel production. This is primarily due to the fast growth rate of these species in a simple aquaculture environment. However, the dilute nature of microalgae culture puts a huge economic burden on the dewatering process especially on an industrial scale. This current study explores the performance and economic viability of chemical flocculation and tangential flow filtration (TFF) for the dewatering of Tetraselmis suecicamicroalgae culture. Results: Results show that TFF concentrates the microalgae feedstock up to 148 times by consuming 2.06 kWh m-3 of energy while flocculation consumes 14.81 kWhm-3 to concentrate the microalgae up to 357 times. Economic evaluation demonstrates that even though TFF has higher initial capital investment than polymer flocculation, the payback period for TFF at the upper extreme ofmicroalgae revenue is ∼1.5 years while that of flocculation is ∼3 years. Conclusion: These results illustrate that improved dewatering levels can be achieved more economically by employing TFF. The performances of these two techniques are also compared with other dewatering techniques.
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In Australia, for more than two decades, a ‘social science’ integrated framework was the favoured approach for delivering subjects such as history and geography. However, such interdisciplinary approaches have continued to attract criticism from various parts of the academic and public spheres and since 2009, a return to teaching the disciplines has been heralded as the ‘new’ way forward. Using discourse analysis techniques associated with Foucauldian archaeology, the purpose of this paper is to examine the Australian Curriculum: Geography document to ascertain the discourses necessary for pre-service teachers to enact effective teaching of geography in a primary setting. Then, based on pre-service teachers’ online survey responses, the paper investigates if such future teachers have the knowledge and skills to interpret, deliver and enact the new geography curriculum in primary classrooms. Finally, as teacher educators, our interest lies in preparing pre-service teachers effectively for the classroom so the findings are used to inform the content of a teacher education course for pre-service primary teachers.
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Iterative computational models have been used to investigate the regulation of bone fracture healing by local mechanical conditions. Although their predictions replicate some mechanical responses and histological features, they do not typically reproduce the predominantly radial hard callus growth pattern observed in larger mammals. We hypothesised that this discrepancy results from an artefact of the models’ initial geometry. Using axisymmetric finite element models, we demonstrated that pre-defining a field of soft tissue in which callus may develop introduces high deviatoric strains in the periosteal region adjacent to the fracture. These bone-inhibiting strains are not present when the initial soft tissue is confined to a thin periosteal layer. As observed in previous healing models, tissue differentiation algorithms regulated by deviatoric strain predicted hard callus forming remotely and growing towards the fracture. While dilatational strain regulation allowed early bone formation closer to the fracture, hard callus still formed initially over a broad area, rather than expanding over time. Modelling callus growth from a thin periosteal layer successfully predicted the initiation of hard callus growth close to the fracture site. However, these models were still susceptible to elevated deviatoric strains in the soft tissues at the edge of the hard callus. Our study highlights the importance of the initial soft tissue geometry used for finite element models of fracture healing. If this cannot be defined accurately, alternative mechanisms for the prediction of early callus development should be investigated.
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This study aimed to provide a detailed evaluation and comparison of a range of modulated beam evaluation metrics, in terms of their correlation with QA testing results and their variation between treatment sites, for a large number of treatments. Ten metrics including the modulation index (MI), fluence map complexity (FMC), modulation complexity score (MCS), mean aperture displacement (MAD) and small aperture score (SAS) were evaluated for 546 beams from 122 IMRT and VMAT treatment plans targeting the anus, rectum, endometrium, brain, head and neck and prostate. The calculated sets of metrics were evaluated in terms of their relationships to each other and their correlation with the results of electronic portal imaging based quality assurance (QA) evaluations of the treatment beams. Evaluation of the MI, MAD and SAS suggested that beams used in treatments of the anus, rectum, head and neck were more complex than the prostate and brain treatment beams. Seven of the ten beam complexity metrics were found to be strongly correlated with the results from QA testing of the IMRT beams (p < 0.00008). For example, Values of SAS (with MLC apertures narrower than 10 mm defined as “small”) less than 0.2 also identified QA passing IMRT beams with 100% specificity. However, few of the metrics are correlated with the results from QA testing of the VMAT beams, whether they were evaluated as whole 360◦ arcs or as 60◦ sub-arcs. Select evaluation of beam complexity metrics (at least MI, MCS and SAS) is therefore recommended, as an intermediate step in the IMRT QA chain. Such evaluation may also be useful as a means of periodically reviewing VMAT planning or optimiser performance.
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This article is something of a brief extension of recent research into deeds of company arrangement (DOCAs) under Pt 5.3A of the Corporations Act 2001 (Cth), conducted with the support of the Australian Restructuring Insolvency & Turnaround Association’s (ARITA’s) Terry Taylor Scholarship (TTS). This article presents some of the findings of that research (namely, the dividend outcomes delivered by sampled Australian DOCAs) in a manner consistent with reports which have recently emerged from similar research conducted in the UK. In so doing, a basic comparison can be made of the performance of Australian DOCAs against analogous UK procedures.
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Internationally there is interest in developing the research skills of pre-service teachers as a means of ongoing professional renewal with a distinct need for systematic and longitudinal investigation of student learning. The current study takes a unique perspective by exploring the research learning journey of pre-service teachers participating in a transnational degree programme. Using a case-study design that includes both a self-reported and direct measure of research knowledge, the results indicate a progression in learning, as well as evidence that this research knowledge is continued or maintained when the pre-service teachers return to their home university. The findings of this study have implications for both pre-service teacher research training and transnational programmes.
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BACKGROUND Traumatic brain injury (TBI) is associated with mo st trauma-related deaths. Secondary brain injury is the leading cause of in-hospital deaths after traumatic brain injury. By early prevention and slowing of the initial pathophysiological mechanism of secondary brain injury, pre- hospital service can signifi cantly reduce case-fata lity rates of TBI. In China, the incidence of TBI is increasing and the proportion of severe TBI is much higher than that in other countries. The objective of this paper is to review the pre-hospital management of TBI in China. DATA SOURCES A literature search was conducted in January 2014 using the China National Knowledge Infrastructure (CNKI). Articles on the assessment and treatment of TBI in pre-hospital settings practiced by Chinese doctors were identified. The information on the assessment and treatment of hypoxemia, hypotension, and brain hern iation was extracted from the identifi ed articles. RESULTS Of the 471 articles identified, 65 met the selecti on criteria. The existing literature indicated that current practices of pre-hospital TBI management in China were sub-optimal and varied considerably across different regions. CONCLUSION Since pre-hospital care is the weakest part of Chinese emergency care, appropriate training programs on pre-hospital TBI management are urgently needed in China.
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Pre-service teacher education institutions are large and complex organizations, which are notoriously difficult to change. One factor is that many change efforts focus largely on individual pre-service teacher educators altering their practice. We report here on our experience using a model for effecting change, which views pre-service teacher education institutions and educators as a part of a much broader system. We identified numerous possibilities for, and constraints on, embedding change, but focus only on two in this paper: participants’ knowledge of change strategies and their leadership capacities. As a result of our study findings and researcher reflections, we argue that being a leader in an academic area within pre-service teacher education does not equate to leadership knowledge or skills to initiate and enact systems-wide change. Furthermore, such leadership capacities must be explicitly developed if education for sustainability is to become embedded in pre-service teacher education.
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This paper reports the details of an experimental study of cold-formed steel hollow section columns at ambient and elevated temperatures. In this study the global buckling behaviour of cold-formed Square Hollow Section (SHS) slender columns under axial compression was investigated at various uniform elevated temperatures up to 700℃. The results of these column tests are reported in this paper, which include the buckling/failure modes at elevated temperatures, and ultimate load versus temperature curves. Finite element models of tested columns were also developed and their behaviour and ultimate capacities at ambient and elevated temperatures were studied. Fire design rules given in European and American standards including the Direct Strength Method (DSM) based design rules were used to predict the ultimate capacities of tested columns at elevated temperatures. Elevated temperature mechanical properties and stress-strain models given in European steel design standards and past researches were used with design rules and finite element models to investigate their effects on SHS column capacities. Comparisons of column capacities from tests and finite element analyses with those predicted by current design rules were used to determine the accuracy of currently available column design rules in predicting the capacities of SHS columns at elevated temperatures and the need to use appropriate elevated temperature material stress-strain models. This paper presents the important findings derived from the comparisons of these column capacities.
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Questions about the practicum within teacher education tend to focus on the amount of time allocated to it in programs. In this research, we were interested in the quality of the experience rather than assuming ‘more is better’. To understand what is going on and where, this study focussed on the school and specially the departmental office of room as a site for workplace learning. Using qualitative methods we constructed narratives from the data provided by a cohort of four-year bachelor degree pre-service teachers during and following their final major (10 week)practicum experience. Using theories of spatiality to make sense of the data, we found that the narratives revealed stories of spaces where compliance, disappointment were the key features of the practicum, and where resistance through absence (from the departmental office) was an important strategy to manage the experience. This research challenges the ‘more is better’ argument.
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GVHD remains the major complication of allo-HSCT. Murine models are the primary system used to understand GVHD, and to develop potential therapies. Several factors are critical for GVHD in these models; including histo- compatibility, conditioning regimen, and T-cell number. We serendipitously found that environmental factors such as the caging system and bedding also significantly impact the kinetics of GVHD in these models. This is important because such factors may influence the experimental conditions required to cause GVHD and how mice respond to various treatments. Consequently, this is likely to alter interpretation of results between research groups, and the perceived effectiveness of experimental therapies.