1,224 research outputs found

    Optimization of an oxide dispersion strengthened Ni-Cr-Al alloy for gas turbine engine vanes

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    The investigation was carried out to determine the optimum alloy within the Ni-16Cr-Al-Y2O3 system for use as a vane material in advanced aircraft gas turbine engines. Six alloys containing nominally 4%, 5% and 6% Al with Y2O3 levels of 0.8% and 1.2% were prepared by mechanical attrition. Six small-scale, rectangular extrusions were produced from each powder lot for property evaluation. The approximate temperatures for incipient melting were found to be 1658 K (2525 F), 1644 K (2500 F) and 1630 K (2475 F) for the 4%, 5% and 6% aluminum levels, respectively. With the exception of longitudinal crystallographic texture, the eight extrusions selected for extensive evaluation either exceeded or were close to mechanical property goals. Major differences between the alloys became apparent during dynamic oxidation testing, and in particular during the 1366 K (2000 F)/500 hour Mach 1 tests carried out by NASA-Lewis. An aluminum level of 4.75% was subsequently judged to be optimum based on considerations of dynamic oxidation resistance, susceptibility to thermal fatigue cracking and melting point

    Enhancing design learning using a digital repository

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    The process of design is context dependent and open-ended, and therefore does not revolve around a specific body of information or knowledge. The educational paradigm shift in the area of engineering design from teaching to coaching and the increased use of social constructivist learning ideals requires students to have access to as wide a range of information as possible. Digital resources provide an excellent opportunity for extending the range of information available to design students and to this end, as part of a joint research program with Stanford University, the University of Strathclyde has developed a groupware product called LauLima to provide students with a collaborative environment which allows them to gather, organise, store and share information. This paper describes the improvement to design learning, based on a Design Knowledge Framework, in a 3rd year product design engineering project from session 03/04 to 04/05 which has been facilitated by the implementation of this technology

    Basic studies on dispersion hardening

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    Transmission electron microscopy and X-ray diffraction observations of substructure and elastic strains in cold worked and annealed dispersion strengthened alloy

    Coaching High School English Teachers in Guided Reading for Struggling Readers

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    Although small-group guided reading is traditionally an elementary school instructional practice, this study details how high school English teachers perceived its implementation in high school classrooms. As part of a larger, multiyear research project, this 2-year study examined a dual-level coaching professional learning program that included two school district literacy coaches, eight provincial literacy facilitators, and 21 high school teachers. Teachers were coached in the implementation of guided reading and small-group instruction to support students in Grades 9–10 who were struggling with reading. Qualitative methods were used to gather data including observations of the professional learning meetings and teachers’ instruction; interviews with literacy coaches, professional literacy facilitators, and teachers; and artifact collection. Data were analyzed using the qualitative software program NVivo. The findings suggest that teacher coaching, modeling, co-planning, discussion, and reflection enhanced teachers’ abilities to support students in their use of metacognitive skills and comprehension strategies during guided reading. Teachers noted some insightful instructional considerations for implementation of elementary instructional practices in their high school English classrooms. Overall, these results have practical implications for teachers seeking to help struggling high school readers

    Goldsmiths Electronic Music Studios: 40 Years

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    This year marks the 40th anniversary of the founding of the Electronic Music Studios (EMS) at Goldsmiths, University of London. The 1968 studio placed Goldsmiths at the forefront of such developments in the UK university sector. 2008 also marks the launch of our EMS Research Group, which brings together a diverse range of interests and activities in computer music research, creative practice and music technology

    Early impulse control: treatment of potential errors within pre-programming and control

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    Early aiming adjustments following an online perturbation are made possible by impulse control. This process may unfold even earlier when perturbations impose a greater risk of a costly overshoot error. Participants executed upward and downward aims to mediate the cost of potential errors—downward overshoots require more energy to correct against gravity. On 33% of the trials, texture elements on the aiming surface were shifted following onset to appear congruent or incongruent with the aiming direction, and consequently generate a misperception of the limb moving slower or faster, respectively. Thus, the risk of potential errors could be influenced by the online perturbation (e.g., increased perceived likelihood of overshooting following the incongruent background). Findings indicated greater undershooting for down compared to up, which reflects the principle of movement optimisation. There was also more undershooting for an incongruent compared to congruent background, which is consistent with early online adjustments counter-acting the misperceived limb velocity. However, there were no interactions throughout the movement trajectory. We suggest that while the initial pre-programme considers the cost of potential errors (target direction), early impulse control fails to discriminate the likelihood of these errors occurring following an online perturbation (moving background)
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