Journal Articles

A Mo-Si-Ti coated γ-TiAl substrate was fabricated using plasma alloying technology to enhance its high temperature wear resistance. The coated substrate was composed of a deposition layer and a diffusion layer, with the grain size decreasing from the substrate toward the coating, forming a gradient structure. XRD and TEM analysis revealed that the deposition layer included the (Ti, Mo)5Si3, TiSi and MoSi2, while the diffusion layer consisted of the γ-TiAl, TiSi and Al8Mo3. Nanoindentation results showed that the coated substrate exhibited high hardness (19.6 GPa), as well as high plastic deformation resistance and load-bearing capacity. Furthermore, the presence of residual compressive stress (−1255.9 MPa), stress concentrations at interfaces between different phases and gradient structure contributed to the high surface fracture toughness of the coated substrate. Wear testing indicated that the lower nanomechanical properties of pristine substrate combined with the dynamic cyclic generation of oxide film during high temperature friction caused to an increase in specific wear rate at loads of 4.2 N and 6.2 N. However, post-oxidation hardness elevation as well as the lubrication and supportive effect of extensively covered oxide film reduced the wear rate as load increased to 8.2 N. The transition from residual compressive stress to tensile stress along with the formation of oxides at grain boundaries reduced the surface fracture toughness of the coated substrate. Meanwhile, the rapid formation and spalling of oxide film resulted in an increase in the specific wear rate of the coated substrate with increasing load. Nevertheless, coated substrate exhibited better wear resistance than pristine substrate owing to its higher surface mechanical properties. The specific wear rates of the coated substrate were 3.7, 6.0 and 19.5 × 10−5 mm3N−1 m−1 at loads of 4.2, 6.2 and 8.2 N, respectively, reflecting reductions of 88.9 %, 84.3 %, and 34.6 % compared to the pristine substrate.

Advanced Oxidation Processes (AOPs) are highly effective for pollutant removal, but achieving an optimal combination of high reactivity, corrosion resistance, and long-term stability remains challenging. In this study, the synthesis of a distinctive hollow prismatic high-entropy oxide, (Co0.2Ni0.2Mn0.2Cu0.2Zn0.2)3O4, derived from complex coordination polymers are presented. This high-entropy oxide exhibits significant lattice distortion effects compared to conventional (Co1/3Ni1/3Mn1/3)3O4 and Co3O4. These distortions reduce the metal-O bond length, which enhances cyclic stability during peroxymonosulfate (PMS) activation for pollutant degradation. Additionally, the improved interaction between the catalyst and PMS enhances the generation of reactive oxygen species (ROS), leading to superior catalytic degradation activity. Electron paramagnetic resonance (EPR) and other analytical techniques identify ·OH, 1O2, O2−· as the primary active species in the (Co0.2Ni0.2Mn0.2Cu0.2Zn0.2)3O4/PMS system. A degradation mechanism for tetracycline (TC) is also proposed. This study introduces an innovative approach to water treatment by employing high-entropy oxides to activate PMS, demonstrating substantial potential for practical applications.

Gamification, or the use of game-like elements for classroom instruction, has been the subject of study by educators. Currently there are no frameworks for enacting gamification in the mathematics classroom. In this paper, we propose a framework for facilitating Mathematics teachers to implement gamification in classrooms. Through gamification, we target to nurture self-directed learners of Mathematics. Our proposed framework is based on a systematic literature review conducted by the researchers. In our proposal, we map the use of various elements of gamification at each phase of learning through to Merrill’s First Principles of Instruction and van Hiele’s Model of Geometric Thinking. An exemplar of a lesson on geometry with the use of the framework is also presented.

In the performative meritocracy of Singapore where academic achievement is seen as the key to success in the society, vocational education is seen as inferior in the education system. This paper examines the educational experiences of vocational youths who went through the Institute of Technical Education (ITE), an institution that is often not seen as a school of choice. We investigate the life and educational experiences of ITE graduates examining interview data collected through the Biographical Narrative Interpretive Method (BNIM), which elicit lived experiences in narrative form. Through studying the graduates’ biographical learning narratives, we explore the opportunities and challenges to human flourishing. This study has implications for enhancing the ecology of learning as well as VET standing in Singapore and beyond.