Magister Educationis - MEd / Role-play is a teaching strategy which is very useful in enhancing the acquisition of knowledge and conceptualisation of some topics in Life Science. According to the theory of constructivism, learning science is a process in which learners construct understanding of the materials. Role-play and constructivism are intertwined, yet role-play as a teaching strategy lacks classroom application in the teaching of Life Sciences. Role-play is not often used in the teaching of Life Sciences, and to be specific, in the teaching of the circulatory system. The study is motivated by learners’ misconceptions of the circulatory system. The study is undertaken to determine the effect of role play on the learners’ conception about the human circulatory system. Random sampling resulted in the selection of one out of 6 grade 10 classes with 49 learners in each from one school in the Metro East District in Cape Town.

L'étude a porté sur la conversion en presence de catalyseurs bimétaliques supportes de trois molécules modèles de polyols (érythritol, xylitol et sorbitol) en phase aqueuse à 150-240 ° C sous 30-120 bar de H2 pour obtenir sélectivement des produits linéaires C4, C5 et C6 désoxygénés qui sont des précurseurs de polymèrs. L'activité catalytique dépend fortement de la nature du support utilisé (TiO2 vs ZrO2) et la plus grande sélectivité pour les produits désoxygénés linéaires voulus C4, C5 et C6 à une conversion de 80% est de 71, 66 et 54%, respectivement, en présence de catalyseur mixte à base de rhodium et du rhenium à 200 ° C sous 80-120 bar. Les caractérisations des catalyseurs par chimisorption de CO, MET-EDX, TGA-MS et XPS suggèrent une distribution et une réductibilité différentes des espèces de Re sur les nanoparticules Rh supportées en fonction du support permettant d'expliquer ces différences / The aim of our research project reports a study of heterogeneously catalyzed conversion of three polyol model molecules (erythritol, xylitol, and sorbitol) in aqueous phase at 150-240 °C under 30-120 bar of H2 to obtain selectively linear deoxygenated C4, C5, and C6 products used as precursors for polymer applications. The activity was strongly dependent on the nature of the support (TiO2 vs ZrO2) and the highest selectivity to the desired linear deoxygenated C4, C5, and C6 products at 80% conversion reached 71, 66, and 54%, respectively, in the presence of Rh–ReOx bimetallic catalysts at 200°C under 80-120 bar. The characterizations of the catalysts by CO chemisorption, TEM-EDX, TGA-MS, and XPS suggest a different distribution and reducibility of Re species over the supported Rh nanoparticles depending on the support that can explain these differences

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