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Open contests a must to endorse PRS leadership, says don
Get PDFComment on the need for open contest in PRS to find the next fully elected president, after the passing of its founder president, Tan Sri James Jemut Masing
Exploring the optical, structural, and gamma shielding performance of Dy₂O₃-Doped Li₂O–B₂O₃–Al₂O₃ glass systems
No full textIn this study, we synthesized Li₂O–B₂O₃–Al₂O₃ glasses incorporating varying amounts of Dy₂O₃ through the melt-quenching method. The glass formulations followed the composition 23Li₂O + (69 - x)B₂O₃ + 8Al₂O₃ + xDy₂O₃, where x was 0, 1, 1.5, 2, 2.5, and 3 mol%. The glass was found to have an amorphous structure through X-ray diffraction analysis, with Fourier-transform infrared spectroscopy revealing the existence of BO₃ and BO₄ structural units. Mass variation and weight loss rates were evaluated using thermogravimetric analysis and differential thermogravimetry. Optical studies indicated that the direct and indirect bandgap energies were between 3.65–3.76 eV and 2.98–3.29 eV, respectively, as the concentration of Dy₂O₃ increased. The Urbach energy showed a decreasing trend with the higher Dy₂O₃ content, indicating improved structural stability and reduced disorder in the glass network. The Phy-X software was used to determine various radiation attenuation parameters for the selected glass samples for photon energies ranging from 0.015 to 15 MeV. As a result, LBAD-3 showed the optimal performance among the samples. At low photon energy, 0.015–0.05 MeV, LAC values varied from 38.56 to 1.89 cm⁻1. The maximum MAC values at 15 keV were recorded as 15.347 cm2/g for the glass samples LBAD-3. At 15 keV, the smallest HVL values are observed to be 0.017 cm, and the highest values for Zeff were found at a low energy photon range (0.015 MeV) with values of 38.73, while the lowest values were found at 9.650 at 15 MeV for LBAD-3 glasses. There was a notable increase in the buildup factor within the 0.1–10 MeV energy range, with a gradual decrease at higher photon energies. Moreover, the computed ΣR values, with a maximum of 0.104 cm⁻1 for the LBAD-3 sample, highlight its strong potential for fast neutron attenuation. The photon shielding capability of the glass was evaluated using the effective removal cross-section, revealing that the glass containing 3 mol% Dy₂O₃ outperformed the other compositions in photon attenuation. This innovative glass system holds the potential for advancing radiation shielding technologies in the future
Tuning the capacitance of graphene-based materials as negative electrode materials for supercapacitor applications
No full textGraphene-based materials (GMs) were hydrothermally fabricated for supercapacitors, with an in-depth investigation of the doping of nitrogen and sulfur into the GMs as negative electrodes being reported for the first time. XRD analysis revealed that graphene oxide (GO) was reduced to form the graphene derivatives, and the GMs exhibited a typical wrinkled sheet morphology. The doping of heteroatoms into the lattice structure of reduced graphene oxide (RGO) was confirmed through the Fourier-transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), thermogravimetric analysis (TGA) and Raman analysis. The electrochemical performance, evaluated using 1 M LiOH, showed that S-doped reduced graphene oxide (SRGO) achieved the highest specific capacitance (Csp) of 339.07 F g−1. Despite containing only 0.38% sulfur in its structure, SRGO exhibited the highest pseudocapacitance contribution (Cp) of 40.37 %, as well as low charge transfer resistance and a promising specific surface area (SSA) of 148.68 m2 g−1, resulting in its superior Csp. Conversely, N, S co-doped reduced graphene oxide (NSRGO) demonstrated the lowest Csp (209.17 F g−1), which was attributed to its relatively low SSA (95.27 m2 g−1) and Cp (25.25 %) compared to RGO and SRGO. Notably, RGO had the greatest SSA (153.40 m2 g−1) among the GMs, leading to a relatively high Csp of 253.48 F g−1. Thus, SRGO emerges as a highly promising negative electrode material for supercapacitors
Exploring adolescents’ multimodal literacy as critical and creative prosumers in digital game-based multimodal composition
No full textDigital gameplay and digital multimodal composition (DMC) are promising multimodal literacy practices. Nevertheless, research on their incorporation in literacy classrooms to foster students’ multimodal literacy skills is lacking. This qualitative case study explored how two groups of Chinese adolescents used multimodal literacy in digital game-based multimodal composition and assumed their role as critical and creative prosumers. Through a 16-session project, the participants used tablets to collaboratively produce short game videos based on design resources obtained during their digital gameplay. The students demonstrated multimodal literacy through understanding, interpreting and applying multimodal semiotic modes for representational, interpersonal, and compositional meaning-making. Furthermore, they played a multifaceted role as prosumers, including critical gamers, reflective video editors, creative designers, and knowledgeable contributors to the gaming community. This study suggested that incorporating digital games for DMC practice is a valuable opportunity for multimodal literacy learning, cultivating students’ criticality and creativity for active participation in the digital era
