A portal of educational resources: providing evidence for matching pedagogy with technology

The TPACK (Technology, Pedagogy and Content Knowledge) model presents the three types of knowledge that are necessary to implement a successful technology-based educational activity. It highlights how the intersections between TPK (Technological Pedagogical Knowledge), PCK (Pedagogical Content Knowledge) and TCK (Technological Content Knowledge) are not a sheer sum up of their components but new types of knowledge. This paper focuses on TPK, the intersection between technology knowledge and pedagogy knowledge – a crucial field of investigation. Actually, technology in education is not just an add-on but is literally reshaping teaching/learning paradigms. Technology modifies pedagogy and pedagogy dictates requirements to technology. In order to pursue this research, an empirical approach was taken, building a repository (back-end) and a portal (front-end) of about 300 real-life educational experiences run at school. Educational portals are not new, but they generally emphasise content. Instead, in our portal, technology and pedagogy take centre stage. Experiences are classified according to more than 30 categories (‘facets’) and more than 200 facet values, all revolving around the pedagogical implementation and the technology used. The portal (an innovative piece of technology) supports sophisticated ‘exploratory’ sessions of use, targeted at researchers (investigating the TPK intersection), teachers (looking for inspiration in their daily jobs) and decision makers (making decisions about the introduction of technology into schools)

Molecular modeling of the influence of crosslink distribution on epoxy polymers

Experimental studies on epoxies report that the microstructure consists of highlycrosslinked localized regions connected with a dispersed phase of low-crosslink density epoxy. Because epoxies play a major role in many structural applications, the influence of the crosslink distribution on the thermo-mechanical properties must be determined. But as experiments cannot reliably report the exact number or distribution of crosslinked covalent bonds present in the molecular network, molecular modeling is a valuable tool that can predict the influence of crosslink distribution on thermo-mechanical properties. In this study, molecular dynamics are used to establish well-equilibrated molecular models of an EPON 862-DETDA epoxy system with a range of crosslink densities and distributions. Crosslink distributions are varied by forming highly crosslinked clusters within the epoxy network and then forming additional crosslinks that connect between clusters. Results of simulations on these molecular models indicate that the thermal expansion coefficient decreases with overall crosslink density, both above and below the glass transition temperature. It is also found that within the range of crosslink distributions investigated, there is no discernible influence of crosslink distribution on the linear thermal expansion coefficient of the epoxy. © 2012 by Gregory M. Odegard