998 resultados para Chemistry, Analytic


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Participatory action research is used by six Thai chemistry teachers being supported to become more 'computer literate' and to develop understandings about the effectiveness of ways of using a chemistry CAI package to support student learning. The study demonstrates a gradual change in their ideas and attitudes to the use of computers in teaching.

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The article traces the history of the "Australian Journal of Education in Chemistry". The journal, which was founded in 1978, is the only refereed periodical that is wholly owned by the Royal Australian Chemical Institute (RACI). It is designed to improve the quality of chemistry teaching and learning in Australia. It was initially called "Chemeda: The Newsletter of the Chemical Education Division RACI". Overview of some article published in the journal is presented.

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Despite the applied importance of cohesion within organisational settings, researchers have yet to reach consensus about the dimensionality of group cohesion, and therefore appropriate tools for its measurement. The way that cohesion has generally been conceptualised has changed over time, but the measures appear not to reflect the underlying theory. This deficiency has impeded attempts to explore the relationship between co-worker cohesion and group performance (Beal et al., 2003; Mullen & Copper, 1994). Given inconsistent findings from previous factor analyses of cohesion, the present study employed exploratory means to help clarify the factor structure of cohesion within the workplace. Potential participants were recruited via the researchers' social networks. This snowballing technique led to 236 participants completing the online questionnaire. Exploratory factor analysis revealed four first-order factors of team commitment, friendliness, interpersonal conflict and communication that collectively accounted for 55.17% of the variance shared among the 75 cohesion items. Subsequently, a single higher-order factor was extracted which accounted for over half of the co-variation among the first order factors. This higher-order factor seems to reflect a general cohesion factor, as it was loaded by a diffuse collection of items, including those from the four lower-order factors as well as items that failed to load onto these lower-order factors. While there were similarities between these results and those of previous studies, the present factor structure did not map perfectly onto any of the existing conceptual models of cohesion. This finding highlights the need to incorporate some alternate factors that have previously been given little consideration.

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The main challenges in the manufacture of composite materials are low surface energy and the presence of silicon-containing contaminants, both of which greatly reduce surface adhesive strength. In this study, carbon fiber (CF) and E-glass epoxy resin composites were surface treated with the Accelerated Thermo-molecular adhesion Process (ATmaP). ATmaP is a multiaction surface treatment process where tailored nitrogen and oxygen functionalities are generated on the surface of the sample through the vaporization and atomization of n-methylpyrrolidone solution, injected via specially designed flame-treatment equipment. The treated surfaces of the polymer composites were analyzed using XPS, time of flight secondary ion mass spectrometry (ToF-SIMS), contact angle (CA) analysis and direct adhesion measurements. ATmaP treatment increased the surface concentration of polar functional groups while reducing surface contamination, resulting in increased adhesion strength. XPS and ToF-SIMS showed a significant decrease in silicon-containing species on the surface after ATmaP treatment. E-glass composite showed higher adhesion strength than CF composite, correlating with higher surface energy, higher concentrations of nitrogen and CO functional groups (from XPS) and higher concentrations of oxygen and nitrogen-containing functional groups (particularly C2H3O+ and C2H5NO+ molecular ions, from ToF-SIMS).