779 research outputs found

    Valuing assessment in teacher education - Multiple-choice competency testing

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    When our focus is on assessment educators should work to value the nature of assessment. This paper presents a new approach to multiple-choice competency testing in mathematics education. The instrument discussed here reflects student competence, encourages self-regulatory learning behaviours and links content with current curriculum documents and with collaborative and cooperative learning episodes

    Disorder-driven electronic localization and phase separation in superconducting Fe1+yTe0.5Se0.5 single crystals

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    We have investigated the influence of Fe-excess on the electrical transport and magnetism of Fe1+yTe0.5Se0.5 (y=0.04 and 0.09) single crystals. Both compositions exhibit resistively determined superconducting transitions (Tc) with an onset temperature of about 15 K. From the width of the superconducting transition and the magnitude of the lower critical field Hc1, it is inferred that excess of Fe suppresses superconductivity. The linear and non-linear responses of the ac-susceptibility show that the superconducting state for these compositions is inhomogeneous. A possible origin of this phase separation is a magnetic coupling between Fe-excess occupying interstitial sites in the chalcogen planes and those in the Fe-square lattice. The temperature derivative of the resistivity drho/dT in the temperature range Tc < T < Ta with Ta being the temperature of a magnetic anomaly, changes from positive to negative with increasing Fe. A log 1/T divergence of the resistivity above Tc in the sample with higher amount of Fe suggests a disorder driven electronic localization.Comment: 7 page

    Effects of business recovery strategies on seismic risk and cost-effectiveness of structural retrofitting for business enterprises

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    Recent earthquakes in Italy have significantly affected productive activities, particularly in business interruption (BI) and, consequently, heavy losses for companies, highlighting the need for appropriate seismic risk assessment and management. To estimate seismic risk accurately, both direct (repair/ replacement) and indirect (BI) losses must be quantified. Companies\u2019 balance sheets can be used to estimate BI losses, which, however, are very sensitive to business recovery strategies (BRSs) devised by corporate managers after the seismic event. The aim of this study is to evaluate the effects of BRSs on seismic risk estimates and consequently on structural retrofitting cost-effectiveness. A loss model (including direct and indirect costs and BRS effects) was defined, based on a real-life case study (a biomedical packaging company that was damaged by the 2012 Italian earthquake but recovered soon after) and was used in parametric risk analyses assessing several types of company vulnerabilities and seismic hazards. In areas with low-to-moderate seismicity, seismic retrofitting of existing reinforced concrete factories may be justified or otherwise, depending on whether BRSs are considered or not
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