87 research outputs found

    Use of ICT tools (Tablet PC) to promote innovative teaching & learning and to develop students' 21st century skills at O' level: An action research case study in Mauritius

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    This paper outlines an action research case study in Mauritius to obtain crucial practitioner insights into the implementation of a Tablet PC project in a State Secondary School (National College) with O'level students, to promote innovative teaching & learning and to develop students' 21st century skills. The research was conducted over four weeks in a French literature class of 32 students when Tablet PC's were used to enhance and innovate their engagement with a satirical comedy play. Questionnaires and feedback forms were used to collect data from the students' perspective, in addition to teacher observations. This study investigates the general attitude of students about using information and communication technologies (ICT) tools such as Tablet PC and specialist softwares, as well as the impact on teaching and learning. It found that despite many limitations in the practicalities of using Tablet PC in schools, this ICT tool positively influenced student's learning behaviour, effective teaching & learning, and helped students develop 21st century skills

    Oxygen reduction in acid media: influence of the heat treatment on the FeNPc(1–20 isomer mixture impregnated on carbon blacks and active charcoals

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    Oxygen reduction with the aid of a number of FeNPc(1–2) impregnated carbon supports in sulphuric acid solutions has been investigated.\ud \ud Loading of the carbon samples amounted to about 10 wt.%. After a 10 day stay in the aerated solutions the samples were investigated with rotating disk electrode and X-ray photoelectron spectroscopy techniques. The most active and stable samples correspond to mono- or submonolayers of FeNPc deposited on high dibutylphthalate adsorption carbon blacks. Comparison with data obtained previously on Norit BrX impregnations emphasizes the rôle of the electron density on the inner nitrogen atoms rather than that on the iron centres

    Oxygen reduction in acid media on supported iron naphthalocyanine: Effect of isomer configuration and pyrolysis

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    O2 reduction in H2SO4 medium has been investigated on FeNPc impregnations on Norit BrX by the rotating disk electrode technique. Important differences in activity and stability were found between the 1,2- and 2,3-FeNPc isomers (pyrolysed or not). XPS analyses show, for the most inactive sample, strong demetallation and nitrogen losses. This phenomenon can be attributed to the differences in flexibility between the FeNPc isomers, which influences their stabilization on the substrate

    Oxygen reduction in an acid medium : electrocatalysis by CoNPc(1,2) impregnated on a carbon black support; effect of loading and heat treatment

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    O2 reduction in an acid medium has been investigated on a transition metal macrocycle, CoNPc(1,2), impregnated on a carbon black support with a high dibutylphthalate adsorption value, using a rotating disk electrode and voltammetry techniques described previously, combined with X-ray photoelectron spectroscopy measurements. Optimal activity was found for a bilayer coverage (n = 2) at 17%-18% w/w loading. Heat treatment seems to be beneficial for n 3: it increases the overall number N of exchanged electrons and improves the electrode wetting. For the most active samples, mixed Co(II)/Co(III) valencies were displayed

    Influence of particle size and mass loading of hard carbon on sodium ion battery rate performance in industrially relevant full cells

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    Sodium-ion batteries (SIBs) represent a great opportunity for stationary storage, back-up power supply and light electric vehicle applications. Energy and power requirements for these applications needs to be satisfied. Beside material improvement, electrode microstructure plays a critical role. Herein, the influence of hard carbon (HC) particle size and mass loading on the rate performance have been comprehensively investigated. This work analyses the relative contribution of ionic resistance within the porous electrode (Rion) in SIB full cells employing relevant mass loadings. Rion was obtained by applying electrochemical impedance spectroscopy (EIS) to symmetrical cells and by fitting a transmission line model (TLM) under "blocking" conditions. The relative contribution of Rion arising from HC electrodes was further compared to the charge transfer resistance (RCT) in full cell configuration utilising a three-electrode cell under "non-blocking" conditions. Results illustrate mass loading to be as far more influential on cell rate performance compared to the two particle sizes analyzed. The three-electrode study reveals the contribution of Rion to be greater than that of RCT at high mass loadings and high states of charge for the HC electrode and elucidates that the gravimetric and volumetric discharge capacity of cells is limited by the layered oxide cathode and HC electrode respectively

    Elucidating tumour-associated microglia/macrophage diversity along glioblastoma progression and under ACOD1 deficiency

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    In glioblastoma (GBM), tumour-associated microglia/macrophages (TAMs) represent the major cell type of the stromal compartment and contribute to tumour immune escape mechanisms. Thus, targeting TAMs is emerging as a promising strategy for immunotherapy. However, TAM heterogeneity and metabolic adaptation along GBM progression represent critical features for the design of effective TAM-targeted therapies. Here, we comprehensively study the cellular and molecular changes of TAMs in the GL261 GBM mouse model, combining single-cell RNA-sequencing with flow cytometry and immunohistological analyses along GBM progression and in the absence of Acod1 (also known as Irg1), a key gene involved in the metabolic reprogramming of macrophages towards an anti-inflammatory phenotype. Similarly to patients, we identify distinct TAM profiles, mainly based on their ontogeny, that reiterate the idea that microglia- and macrophage-like cells show key transcriptional differences and dynamically adapt along GBM stages. Notably, we uncover decreased antigen-presenting cell features and immune reactivity in TAMs along tumour progression that are instead enhanced in Acod1-deficient mice. Overall, our results provide insight into TAM heterogeneity and highlight a novel role for Acod1 in TAM adaptation during GBM progression.publishedVersio
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