634 resultados para space centre
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A review of 291 catalogued particles on the bases of particle size, shape, bulk chemistry, and texture is used to establish a reliable taxonomy. Extraterrestrial materials occur in three defined categories: spheres, aggregates and fragments. Approximately 76% of aggregates are of probable extraterrestrial origin, whereas spheres contain the smallest amount of extraterrestrial material (approx 43%). -B.M.
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Tina Fiveash: Grace; Shannon Brett: I didn't get to cry till now; Ana Paula Estrada: Of another time; Janina Green: Be home before Dark; Paul Batt: Escalator Series 2011.
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Discourses of public education reform, like that exemplified within the Queensland Government’s future vision document, Queensland State Education-2010 (QSE-2010), position schooling as a panacea to pervasive social instability and a means to achieve a new consensus. However, in unravelling the many conflicting statements that conjoin to form education policy and inform related literature (Ball, 1993), it becomes clear that education reform discourse is polyvalent (Foucault, 1977). Alongside visionary statements that speak of public education as a vehicle for social justice are the (re)visionary or those reflecting neoliberal individualism and a conservative politics. In this paper, it is argued that the latter coagulate to form strategic discursive practices which work to (re)secure dominant relations of power. Further, discussion of the characteristics needed by the “ideal” future citizen of Queensland reflect efforts to ‘tame change through the making of the child’ (Popkewitz, 2004, p.201). The casualties of this (re)vision and the refusal to investigate the pathologies of “traditional” schooling are the children who, for whatever reason, do not conform to the norm of the desired school child as an “ideal” citizen-in-the-making and who become relegated to alternative educational settings.
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Scientific and programmatic progress toward the development of a cosmic dust collection facility (CDCF) for the proposed space station is documented. Topics addressed include: trajectory sensor concepts; trajectory accuracy and orbital evolution; CDCF pointing direction; development of capture devices; analytical techniques; programmatic progress; flight opportunities; and facility development.
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Many commentators have treated the internet as a site of democratic freedom and as a new kind of public sphere. While there are good reasons for optimism, like any social space digital space also has its dark side. Citizens and governments alike have expressed anxiety about cybercrime and cyber-security. In August 2011, the Australian government introduced legislation to give effect to Australia becoming a signatory to the European Convention on Cybercrime (2001). At the time of writing, that legislation is still before the Parliament. In this article, attention is given to how the legal and policy-making process enabling Australia to be compliant with the European Convention on Cybercrime came about. Among the motivations that informed both the development of the Convention in Europe and then the Australian exercise of legislating for compliance with it was a range of legitimate concerns about the impact that cybercrime can have on individuals and communities. This article makes the case that equal attention also needs to be given to ensuring that legislators and policy makers differentiate between legitimate security imperatives and any over-reach evident in the implementation of this legislation that affects rule of law principles, our capacity to engage in democratic practices, and our civic and human rights.
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Since March 2010 in Queensland, legislation has specified the type of restraint and seating row for child passengers under 7 years according to age. The following study explored regional parents’ child restraint practices and the influence of their health beliefs over these. A brief intercept interview was verbally administered to a convenience sample of parent-drivers (n = 123) in Toowoomba in February 2010, after the announcement of changes to legislation but prior to enforcement. Parents who agreed to be followed-up were then reinterviewed after the enforcement (May-June 2010). The Health Beliefs Model was used to gauge beliefs about susceptibility to crashing, children being injured in a crash, and likely severity of injuries. Self-efficacy and perceptions about barriers to, and benefits of, using age-appropriate restraints with children, were also assessed. Results: There were very high levels of rear seating reported for children (initial interview 91%; follow-up 100%). Dedicated child restraint use was 96.9% at initial interview, though 11% were deemed inappropriate for the child’s age. Self-reported restraint practices for children under 7 were used to categorise parental practices into ‘Appropriate’ (all children in age-appropriate restraint and rear seat) or ‘Inappropriate’ (≥1 child inappropriately restrained). 94% of parents were aware of the legislation, but only around one third gave accurate descriptions of the requirements. However, 89% of parents were deemed to have ‘Appropriate’ restraint practices. Parents with ‘Inappropriate’ practices were significantly more likely than those with ‘Appropriate’ practices to disagree that child restraints provide better protection for children in a crash than adult seatbelts. For self-efficacy, parents with ‘Appropriate’ practices were more likely than those with ‘Inappropriate’ practices to report being ‘completely confident’ about installing child restraints. The results suggest that efforts to increase the level of appropriate restraint should attempt to better inform them about the superior protection offered by child restraints compared with seat belts for children.
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This chapter considers to what degree the careers of women with young families, both in and out of paid employment, are lived as contingent, intersubjective projects pursued across time and space, in the social condition of growing biographical possibilities and uneven social/ideological change. Their resolutions of competing priorities by engaging in various permutations of home-work and paid work are termed ‘workable solutions’, with an intentional play on the double sense of ‘work’ – firstly as labour, thus being able to perform work, whether paid or not; secondly as in being able to make things work or function in the family unit’s best interests, however defined.
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Within the communicative space online Social Network Sites (SNS) afford, Niche Social Networks Sites (NSNS) have emerged around particular geographic, demographic or topic-based communities to provide what broader SNS do not: specified and targeted content for an engaged and interested community. Drawing on a research project developed at the Queensland University of Technology in conjunction with the Australian Smart Services Cooperative Research Centre that produced an NSNS based around Adventure Travel, this paper outlines the main drivers for community creation and sustainability within NSNS. The paper asks what factors motivate users to join and stay with these sites and what, if any, common patterns can be noted in their formation. It also outlines the main barriers to online participation and content creation in NSNS, and the similarities and differences in SNS and NSNS business models. Having built a community of 100 registered members, the staywild.com.au project was a living laboratory, enabling us to document the steps taken in producing a NSNS and cultivating and retaining active contributors. The paper incorporates observational analysis of user-generated content (UGC) and user profile submissions, statistical analysis of site usage, and findings from a survey of our membership pool in noting areas of success and of failure. In drawing on our project in this way we provide a template for future iterations of NSNS initiation and development across various other social settings: not only niche communities, but also the media and advertising with which they engage and interact. Positioned within the context of online user participation and UGC research, our paper concludes with a discussion of the ways in which the tools afforded by NSNS extend earlier understandings of online ‘communities of interest’. It also outlines the relevance of our research to larger questions about the diversity of the social media ecology.
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A body of research in conversation analysis has identified a range of structurally-provided positions in which sources of trouble in talk-in-interaction can be addressed using repair. These practices are contained within what Schegloff (1992) calls the repair space. In this paper, I examine a rare instance in which a source of trouble is not resolved within the repair space and comes to be addressed outside of it. The practice by which this occurs is a post-completion account; that is, an account that is produced after the possible completion of the sequence containing a source of trouble. Unlike fourth position repair, the final repair position available within the repair space, this account is not made in preparation for a revised response to the trouble-source turn. Its more restrictive aim, rather, is to circumvent an ongoing difference between the parties involved. I argue that because the trouble is addressed in this manner, and in this particular position, the repair space can be considered as being limited to the sequence in which a source of trouble originates.
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In this submission, we provide evidence for our view that copyright policy in the UK must encourage new digital business models which meet the changing needs of consumers and foster innovation in the UK both within, and beyond, the creative industries. We illustrate our arguments using evidence from the music industry. However, we believe that our key points on the relationship between the copyright system and innovative digital business models apply across the UK creative industries.
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Background: Hyperpolarised helium MRI (He3 MRI) is a new technique that enables imaging of the air distribution within the lungs. This allows accurate determination of the ventilation distribution in vivo. The technique has the disadvantages of requiring an expensive helium isotope, complex apparatus and moving the patient to a compatible MRI scanner. Electrical impedance tomography (EIT) a non-invasive bedside technique that allows constant monitoring of lung impedance, which is dependent on changes in air space capacity in the lung. We have used He3MRI measurements of ventilation distribution as the gold standard for assessment of EIT. Methods: Seven rats were ventilated in supine, prone, left and right lateral position with 70% helium/30% oxygen for EIT measurements and pure helium for He3 MRI. The same ventilator and settings were used for both measurements. Image dimensions, geometric centre and global in homogeneity index were calculated. Results: EIT images were smaller and of lower resolution and contained less anatomical detail than those from He3 MRI. However, both methods could measure positional induced changes in lung ventilation, as assessed by the geometric centre. The global in homogeneity index were comparable between the techniques. Conclusion: EIT is a suitable technique for monitoring ventilation distribution and inhomgeneity as assessed by comparison with He3 MRI.
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We develop a fast Poisson preconditioner for the efficient numerical solution of a class of two-sided nonlinear space fractional diffusion equations in one and two dimensions using the method of lines. Using the shifted Gr¨unwald finite difference formulas to approximate the two-sided(i.e. the left and right Riemann-Liouville) fractional derivatives, the resulting semi-discrete nonlinear systems have dense Jacobian matrices owing to the non-local property of fractional derivatives. We employ a modern initial value problem solver utilising backward differentiation formulas and Jacobian-free Newton-Krylov methods to solve these systems. For efficient performance of the Jacobianfree Newton-Krylov method it is essential to apply an effective preconditioner to accelerate the convergence of the linear iterative solver. The key contribution of our work is to generalise the fast Poisson preconditioner, widely used for integer-order diffusion equations, so that it applies to the two-sided space fractional diffusion equation. A number of numerical experiments are presented to demonstrate the effectiveness of the preconditioner and the overall solution strategy.
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The method of lines is a standard method for advancing the solution of partial differential equations (PDEs) in time. In one sense, the method applies equally well to space-fractional PDEs as it does to integer-order PDEs. However, there is a significant challenge when solving space-fractional PDEs in this way, owing to the non-local nature of the fractional derivatives. Each equation in the resulting semi-discrete system involves contributions from every spatial node in the domain. This has important consequences for the efficiency of the numerical solver, especially when the system is large. First, the Jacobian matrix of the system is dense, and hence methods that avoid the need to form and factorise this matrix are preferred. Second, since the cost of evaluating the discrete equations is high, it is essential to minimise the number of evaluations required to advance the solution in time. In this paper, we show how an effective preconditioner is essential for improving the efficiency of the method of lines for solving a quite general two-sided, nonlinear space-fractional diffusion equation. A key contribution is to show, how to construct suitable banded approximations to the system Jacobian for preconditioning purposes that permit high orders and large stepsizes to be used in the temporal integration, without requiring dense matrices to be formed. The results of numerical experiments are presented that demonstrate the effectiveness of this approach.
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We consider a two-dimensional space-fractional reaction diffusion equation with a fractional Laplacian operator and homogeneous Neumann boundary conditions. The finite volume method is used with the matrix transfer technique of Ilić et al. (2006) to discretise in space, yielding a system of equations that requires the action of a matrix function to solve at each timestep. Rather than form this matrix function explicitly, we use Krylov subspace techniques to approximate the action of this matrix function. Specifically, we apply the Lanczos method, after a suitable transformation of the problem to recover symmetry. To improve the convergence of this method, we utilise a preconditioner that deflates the smallest eigenvalues from the spectrum. We demonstrate the efficiency of our approach for a fractional Fisher’s equation on the unit disk.