No abstract

Nanoindentation has become ubiquitous for the measurement of mechanical properties at ever-decreasing scales of interest, including some studies that have explored the atomic-level origins of plasticity in perfect crystals. With substantial guidance from atomistic simulations, the onset of plasticity during nanoindentation is now widely believed to be associated with homogeneous dislocation nucleation. However, to date there has been no compelling quantitative experimental support for the atomic-scale mechanisms predicted by atomistic simulations. Our purpose here is to significantly advance the quantitative potential of nanoindentation experiments for the study of dislocation nucleation. This is accomplished through the development and application of high-temperature nanoindentation testing, and the introduction of statistical methods to quantitatively evaluate data. The combined use of these techniques suggests an unexpected picture of incipient plasticity that involves heterogeneous nucleation sites, and which has not been anticipated by atomistic simulations.

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Research which focuses on children's perspectives of their well-being complements and challenges existing research and policy on children. The study reported on here explored children's views of what constitutes well-being, what meaning children and young people ascribe to the concept and whether distinct dimensions or characteristics of well-being can be identified. The project was initiated by the New South Wales Commission for Children and Young People as a basis for developing an authoritative child-informed framework for monitoring of well-being of children in New South Wales, Australia. In this paper, we outline the rationale for and details of qualitative research methods employed in the project, along with details of the major findings from the research. These include, the overarching importance of relationships with others and, more specifically, the importance of agency and control in the various domains identified as relevant to their wellbeing, the importance of safety and security and the way these factors contribute to sense of self. More minor but significant domains identified were: dealing with adversity, material and economic resources, physical environments, physical health and social and moral responsibility. The significance of the findings for policy development and the particular challenge of developing indicators from the research are discussed.

There is a lack of consideration for the effects that labels such as autism, and the associated diagnostic processes, have on the children to whom they are applied. In this article we present research conducted with five teenagers diagnosed with autism. Through a collaborative, participatory research approach, these teenagers shared their experiences of their diagnosis using communication methods of their choice. The young people's accounts illustrate the understandings they had of autism. Important findings from the research illustrate how the participants integrated this knowledge with their sense of self, how they negotiated issues of identity and the meanings that feeling 'different' had for them. Whether the diagnosis was experienced as advantage or disadvantage by the young people depended on the extent to which it facilitated knowledge and control. The article concludes with a discussion of the significance a diagnosis may have for the ways in which children and young people construct their personal identity and their social relations, and in terms of negotiating control in their lives. We suggest that ways of minimising stigma and marginalisation associated with a diagnosis of autism need to be considered at a policy level.

children's perspectives, indicators, well-being,

No abstract

We introduce a general, efficient method to completely describe the topology of individual grains, bubbles, and cells in three-dimensional polycrystals, foams, and other multicellular microstructures. This approach is applied to a pair of three-dimensional microstructures that are often regarded as close analogues in the literature: one resulting from normal grain growth (mean curvature flow) and another resulting from a random Poisson-Voronoi tessellation of space. Grain growth strongly favors particular grain topologies, compared with the Poisson-Voronoi model. Moreover, the frequencies of highly symmetric grains are orders of magnitude higher in the the grain growth microstructure than they are in the Poisson-Voronoi one. Grain topology statistics provide a strong, robust differentiator of different cellular microstructures and provide hints to the processes that drive different classes of microstructure evolution.