826 resultados para Lynn


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All relevant international standards for determining if a metallic rod is flammable in oxygen utilize some form of “promoted ignition” test. In this test, for a given pressure, an overwhelming ignition source is coupled to the end of the test sample and the designation flammable or nonflammable is based upon the amount burned, that is, a burn criteria. It is documented that (1) the initial temperature of the test sample affects the burning of the test sample both (a) in regards to the pressure at which the sample will support burning (threshold pressure) and (b) the rate at which the sample is melted (regression rate of the melting interface); and, (2) the igniter used affects the test sample by heating it adjacent to the igniter as ignition occurs. Together, these facts make it necessary to ensure, if a metallic material is to be considered flammable at the conditions tested, that the burn criteria will exclude any region of the test sample that may have undergone preheating during the ignition process. A two-dimensional theoretical model was developed to describe the transient heat transfer occurring and resultant temperatures produced within this system. Several metals (copper, aluminum, iron, and stainless steel) and ignition promoters (magnesium, aluminum, and Pyrofuze®) were evaluated for a range of oxygen pressures between 0.69 MPa (100 psia) and 34.5 MPa (5,000 psia). A MATLAB® program was utilized to solve the developed model that was validated against (1) a published solution for a similar system and (2) against experimental data obtained during actual tests at the National Aeronautics and Space Administration White Sands Test Facility. The validated model successfully predicts temperatures within the test samples with agreement between model and experiment increasing as test pressure increases and/or distance from the promoter increases. Oxygen pressure and test sample thermal diffusivity were shown to have the largest effect on the results. In all cases evaluated, there is no significant preheating (above about 38°C/100°F) occurring at distances greater than 30 mm (1.18 in.) during the time the ignition source is attached to the test sample. This validates a distance of 30 mm (1.18 in.) above the ignition promoter as a burn length upon which a definition of flammable can be based for inclusion in relevant international standards (that is, burning past this length will always be independent of the ignition event for the ignition promoters considered here. KEYWORDS: promoted ignition, metal combustion, heat conduction, thin fin, promoted combustion, burn length, burn criteria, flammability, igniter effects, heat affected zone.

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Promoted ignition testing [1–3] is used to determine the relative flammability of metal rods in oxygen-enriched atmospheres. In these tests, a promoter is used to ignite each metal rod to start the sample burning. Experiments were performed to better understand the promoted ignition test by obtaining insight into the effect a burning promoter has on the preheating of a test sample. Test samples of several metallic materials were prepared and coupled to fast-responding thermocouples along their length. Various ignition promoters were used to ignite the test samples. The thermocouple measurements and test video were synchronized to determine temperature increase with respect to time and length along each test sample. A recommended length of test sample that must be consumed to be considered a flammable material was determined based on the preheated zone measured from these tests. This length was determined to be 30 mm (1.18 in.). Validation of this length and its rationale are presented.

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In mid 2007, the Australian Learning and Teaching Council (ALTC), formerly the Carrick Institute for Learning and Teaching in Higher Education, commissioned an intensive research project to examine the use of ePortfolios by university students in Australia. The project was awarded to a consortium of four universities: Queensland University of Technology as lead institution, The University of Melbourne, University of New England and University of Wollongong.---------- The overarching aim of the research project, which was given the working title of the Australian ePortfolio Project, was to examine the current levels of ePortfolio practice in Australian higher education. The principal project goals sought to provide an overview and analysis of the national and international ePortfolio contexts, document the types of ePortfolios used in Australian higher education, examine the relationship with the National Diploma Supplement project funded by the Federal government, identify any significant issues relating to ePortfolio implementation, and offer guidance about future opportunities for ePortfolio development. The research findings revealed that there was a high level of interest in the use of ePortfolios in the context of higher education, particularly in terms of the potential to help students become reflective learners who are conscious of their personal and professional strengths and weaknesses, as well as to make their existing and developing skills more explicit. There were some good examples of early adoption in different institutions, although this tended to be distributed across the sector. The greatest use of ePortfolios was recorded in coursework programs, rather than in research programs, with implementation generally reflecting subject-specific or program-based activity, as opposed to faculty- or university-wide activity. Accordingly, responsibility for implementation frequently rested with the individual teaching unit, although an alternative centralised model of coordination by ICT services, careers and employment or teaching and learning support was beginning to emerge. The project report concludes with a series of recommendations to guide the process, drawing on the need for open dialogue and effective collaboration between the stakeholders across the range of contexts: government policy, international technical standards, academic policy, and learning and teaching research and practice.

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This report documents Stage Two of the Australian ePortfolio Project (AeP2), to specifically explore the current scope of national and international ePortfolio communities of practice in order to identify the factors that have contributed to their success and sustainability. The study has built on Stage One of the Australian ePortfolio Project (Hallam, Harper, McCowan, Hauville, McAllister, & Creagh, 2008), which outlined the broad range of issues and challenges, as well as significant opportunities, that faced the higher education sector in terms of ePortfolio practice, to determine how the emergent community of ePortfolio researchers and practitioners in Australia might be advanced. ---------- The overarching aims of this project were to focus on building the Australian community of practice through an online forum and further symposium activities. Through the research activities the project sought to generate the following major outcomes: develop a forum within the ALTC Exchange to support an ePortfolio community of practice; develop strategies to encourage interest in and engagement with community of practice activities; develop and promote resources to support the diverse stakeholders in ePortfolio practice; collaborate in the establishment of a cross-sector ePortfolio community of practice; host a second Australian ePortfolio Symposium (AeP2) to disseminate the findings from the Australian ePortfolio Project, to explore innovative practice in ePortfolio use in higher education, to articulate policy developments, and to stimulate discussion on international ePortfolio issues; host an associated trade display as a forum for strengthening the higher education sector’s understanding of the features and functionality of ePortfolio platforms; develop resources to support an ePortfolio symposium model that may be adopted for future events. ----------- The project activities encompassed a survey of stakeholders, a program of semi-structured interviews with community managers and a series of case studies depicting successful ePortfolio communities. The survey of ePortfolio practitioners sought to determine the potential value of an ePortfolio CoP, the preferred focus for and the desired features of such a community, as well as the options for the technical and social architecture of an online forum. Through the semi-structured interviews it was possible to examine current examples of CoP activity, to identify the critical success factors and the challenges faced by individual ePortfolio CoPs, so that the attributes of good practice could be presented. The data collected in the interviews contributed to the development of 14 case studies, which have been beneficial in illustrating the diverse nature of CoPs in Australia and overseas.----------- The report presents a rich picture of national and international ePortfolio communities of practice, with an examination of the factors that have contributed to their success and sustainability.

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Data generated in a normal gravity environment is often used in design and risk assessment for reduced gravity applications. It has been clearly demonstrated that this is a conservative approach for non-metallic materials which have been repeatedly shown to be less flammable in a reduced gravity environment. However, recent work has demonstrated this is not true for metallic materials. This work, conducted in a newly completed drop tower observed a significant increase in both lowest burn pressure and burn rate in reduced gravity. Hence the normal gravity qualification of a metallic materials’ lowest burn pressure or burn rate for reduced-gravity or space-based systems is clearly not conservative. This paper presents a summary of this work and the results obtained for several metallic materials showing an increased flammability and burn rate for a range of oxygen pressures, and discusses the implications of this work on the fire-safety of space-based systems.

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The challenge for all educators is to fuse the learning of information literacy to an academic education in such a way that the outcome is systematic and sustainable learning for students. This challenge can be answered through long-term commitment to information literacy education bound to organisation-wide, renewable strategic planning and driven through systemic reform. This chapter seeks to explore the two sides of reforming information literacy education in an academic environment. Specifically, it will examine how one Australian university has undertaken the implementation of a rigorous strategic, systemic approach to information literacy learning and teaching.

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With the massive decline in savings arising from the Global Financial Crisis (GFC), it is timely to review superannuation fund investment and disclosure strategies in the lead-up to the crisis. Accordingly, this study examines differences among superannuation funds’ default investment options in terms of naming and framing over three years from 2005 to 2007, as presented in product disclosure statements (PDSs). The findings indicate that default options are becoming more alike regardless of their name, and consequently, members may face increasing difficulties in distinguishing between balanced and growth-named default options when comparing them across superannuation funds. Comparability is also likely to be constrained by variations in the framing of default options presented in investment option menus in PDSs. These findings highlight the need for standardisation of default option definitions and disclosures to ensure descriptive accuracy, transparency and comparability.