1,749 research outputs found

    Studentsā€™ Use of Knowledge Resources in Environmental Interaction on an Outdoor Learning Trail

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    This study examined how students leveraged different types of knowledge resources on an outdoor learning trail. We positioned the learning trail as an integral part of the curriculum with a pre- and post-trail phase to scaffold and to support studentsā€™ meaning-making process. The study was conducted with two classes of secondary two students. We coded two groupsā€™ discourse to examine the use of knowledge resource types in the meaning-making process in an outdoor learning setting: contextual resource, new conceptual resource, prior knowledge resource, as well as the relationship among these knowledge resource types. Next, we also examined environmental interaction and integration in the studentsā€™ use of these knowledge resource types. Analysis showed that contextual resources are chiefly instrumental in fostering studentsā€™ capacity to harness new conceptual resource and to activate prior knowledge resource in interacting with and integrating the outdoor learning environment in the meaning-making process.This research is supported by the FutureSchools@Singapore project under the Singapore National Research Foundationā€™s (NRF) Interactive and Digital Media (IDM) in Education Research and Development (R&D) Programme

    Rethinking the Impact of Activity Design on a Mobile Learning Trail: The Missing Dimension of the Physical Affordances

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    This paper investigates the relationship between activity design and discourse on a mobile learning trail, considering the physical affordances of the real world platform in designing contextual learning experiences. We adopted a context-oriented and process-oriented pedagogical approach in designing the mobile learning trail conducted at Singapore Sentosa Island. Activities were categorized into performative and knowledge-generative on a continuum from well-structured to ill-structured activities. To examine the impact of activity design on discourse types, all audio-recorded verbal data of the three groups of secondary students was analysed with respect to two key dimensions in the knowledge construction process, namely, the epistemic and the social. Analysis showed that activity types and physical affordances of the learning environment have a definitive bearing on group discursive moves. Importantly, the presence of a real world context could generate critical thinking and collaborative knowledge building even for mundane performative activities when they are embedded with unforeseen contextual variables. We argue that the design of activity and the degree of its structuredness, and the assumed desired learning outcomes, are very much subjected to the affordances of physical and social resources in the mobile learning environment-a missing dimension that could possibly be overlooked and understudied.X1144Ysciessciscopu

    Biochar From Waste Banana Peels as Growth Promoter for Holy Basil (Ocimum tenuiflorum) And Chili Pepper (Capsicum annuum)

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    Biochars are porous materials prepared by combustion of biomass under the presence of low oxygen levels. Its application as soil fertilizer has been shown to have positive effects on the plants by increasing the fertility and raising the soil pH, increasing nutrient cycling and moisture holding capacity, improving cation exchange capacity, and reducing the amount of pesticides and nutrients leaching to the surface and ground water (Laird 2008, Speratti 2017). In this study, waste banana peels of the Lakatan variety (Musa x paradisiaca) were pyrolized at temperatures 300, 400, 500 and 700 Ā°C, the resulting basic char were obtained at 4-9% yield. The char from the different pyrolysis conditions were characterized and evaluated as growth promoter for holy basil (Ocimum tenuiflorum) and chili pepper (Capsicum annuum). The results show that the ability of the char to promote growth were found to be beneficial when the pyrolysis temperature of the char is lower (300 ā€“ 500 Ā°C) for both plants. Conversely, the soil containing 1 wt% of char was found to be beneficial to the growth of chili compared to the control

    A flexible AC distribution system device for a microgrid

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    Smart distribution network device for microgrid applications

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    This paper focuses on the design of a smart distribution network device for improving the power quality and reliability of the overall power distribution system that the microgrid is connected to. The control design employs a newly developed Model Predictive Control algorithm which optimizes the steady-state and the transient control problems separately to achieve a faster computational time for large power systems. Kalman filters are also employed as state observers to identify the required signals needed for monitoring purposes as well as to extract the harmonic spectra of the grid voltage and the load currents. The design concept is verified through different test case scenarios to demonstrate the capability of the proposed device and the results obtained are discussed. Ā© 2012 IEEE.published_or_final_versio

    Coordinated control and energy management of distributed generation inverters in a microgrid

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    Synthesis and Properties of Poly[p-(2,5-dihydroxy)-phenylenebenzobisoxazole] Fiber

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    The novel polymer poly[p-(2,5-dihydroxy)-phenylenebenzobisoxazole] (PBOH) fiber was synthesized in the presence of 2,5-dihydroxyterephthalicacid (DHTA) and 4,6-diamino-1,3-benzenediol in poly(phosphoric acid) (PPA) using typical polycondensation conditions. The crystalline solutions of liquid PBOH in PPA were spun into fibers using dry-jet wet spinning. Furthermore, the thermostability and mechanical properties of PBOH were compared with poly(p-phenylene-2,6-benzoxazole) (PBO) in order to investigate the relationship between the chain structure and properties. The results indicated that the thermal degradation temperature of PBOH was above 750K and the tensile strength of the PBOH fiber was 3.1GPa, which were much lower than those of PBO fiber. The compressive strength of PBOH fiber was 331 M Pa, which was slightly higher than that of PBO fiber. In addition, molecular simulation was employed to explain why the compressive strength of PBOH fiber did not increase significantly compared to PBO fiber

    Treadmill exercise suppressed stress-induced dendritic spine elimination in mouse barrel cortex and improved working memory via BDNF/TrkB pathway

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    Evaluation of Silica Sol-Gel Microcapsule for the Controlled Release of Insect Repellent, N,N-Diethyl-2-methoxybenzamide, on Cotton

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    N,N-diethyl-2-methoxybenzamide, an insect repellent compound, was incorporated into cotton textile using the sol-gel method. Evaluation of the results of four different sol-gel formulations showed that a lower condensation rate resulted in significantly better encapsulation. Also investigated was the encapsulation in the presence of other polymers like polymethylmethacrylate (PMMA), polystyrene (PS) and polyvinyl alcohol (PVA) that prolong the release of the repellent. The sol-gel formulation, SiO2 : polymethylmethacrylate (PMMA) (1:0.8), gave smooth fabric and good encapsulation of the insect repellent compound. PS and PVA resulted in cloths which are aesthetically undesirable. Cloths coated with sol-gel PVA gave the best repellent release profile
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