171 research outputs found

    The effect of cooling rate and grain size on hydride formation in Zircaloy-4

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    We explore the distribution, morphology and structure of zirconium hydrides formed using different cooling rates through the solid state Zr+[H] --> Zr + hydride transus, in fine and blocky alpha Zircaloy-4. We observe that cooling rate and grain size control the phase and distribution of hydrides. The blocky alpha (coarse grain, > 200 micrometer) Zircaloy-4, has a smaller grain boundary area to grain volume ratio and this significantly affects nucleation and growth of hydrides as compared to fine grain size (~11 micrometer) material.Comment: Submitted for peer review as a short communication, changes for second submission highlighte

    An iterative method for reference pattern selection in high-resolution electron backscatter diffraction (HR-EBSD)

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    For high (angular) resolution electron backscatter diffraction (HR-EBSD), the selection of a reference diffraction pattern (EBSP0) significantly affects the precision of the calculated strain and rotation maps. This effect was demonstrated in plastically deformed body-centred cubic and face-centred cubic ductile metals (ferrite and austenite grains in duplex stainless steel) and brittle single-crystal silicon, which showed that the effect is not only limited to measurement magnitude but also spatial distribution. An empirical relationship was then identified between the cross-correlation parameter and angular error, which was used in an iterative algorithm to identify the optimal reference pattern that maximises the precision of HR-EBSD

    Evaluating the ESL Reading Texts for Intermediate Learners of English from the Perspective of Students

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    In order to provide an evaluation of the suitability of reading texts from the perspective of students in university-based intensive English programme this study examined 53 international ESL intermediate learners perceptions of reading texts for a period of 14 weeks reading proficiency lessons Features evaluated include content readability exploitability and authenticity of the reading texts The participants responded to a textbook evaluation questionnaire to express their perceptions with reference to the features of the reading texts Results indicated the extent of appropriateness of the reading texts incorporated in the programme s reading textbook used by intermediate learners of English Further consideration must be given to text selection by including the aspect of authentic text presentatio
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