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  • Publication
    Wear and friction properties of pineapple leaf fibers‐reinforced natural rubber composites with the influence of multi‐walled carbon nanotubes
    (John Wiley and Sons Inc, 2025)
    Yeo Yi Xuan
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    ; ;
    S. M. Sapuan
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    ;
    This study advances the creation of biocomposite materials and serves to reduce and utilize agricultural waste such as pineapple leaf fibers (PALF). In this study, PALF-reinforced natural rubber (NR) composites with included multi-walled carbon nanotubes (MWCNT) were analyzed and characterized at various fiber loadings. The PALF content was ranged from 0, 10, 20 to 30 parts per hundred rubber (phr) while the MWCNT content was maintained at 10 phr. A two-roll mill mixing process followed by molding was employed to fabricate the NR composites. Based on the curing behavior, tribological properties, and morphological analysis, it was confirmed that the hybrid reinforcement of the MWCNT and PALF improved the curing behavior, wear resistance, and morphology of the composites. The wear and friction properties of the composites namely coefficient of friction (COF), frictional force and specific wear rate (SWR) are significantly influenced by the applied loads. The COF of NR/30PALF and NR/30PALF/MWCNT composites is reduced to 0.80 and 0.72 respectively under 15 N of load. Physical properties namely the cross-link density and swelling behavior of the composites ranged from 3.70 × 10−4 to 5.71 × 10−4 mol/cm3 and 207.81 to 386.17%, respectively. According to the results obtained, the best cure and wear behavior followed by the morphological analysis are observed in NR/30PALF/MWCNT composite. Among the samples tested, NR/30PALF composite exhibited the best performance in both cross-link density and swelling behavior. It is anticipated that the findings of this study are expected to provide theoretical data for the design and optimisation of high-performance automotive and footwear applications. Highlights: NR/30PALF/MWCNT hybrid composite exhibited the shortest (Formula presented.) The addition of MWCNT improved the wear resistance of the composites The reinforcement of PALF at 30 phr possessed the lowest swelling ratio and the highest cross-link density of the composites The addition of MWCNT decreased cross-link density of the composites.
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  • Publication
    Abrasive wear performance of repair welds on R260 rail using different welding electrodes
    (Elsevier, 2025-06)
    Prapas Muangjunburee
    ;
    Hein Zaw Oo
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    ;
    Buntoeng Srikarun
    This study compares the abrasion resistance of unrepaired base rail steel grade R260 to three different welds repaired using shielded metal arc welding (SMAW). Three different types of pearlitic covered electrodes were utilized in this study. Rail steel and repaired weld metals were examined for chemical composition, microstructure, hardness, wear test, and worn surface. The repaired weld metal using covered electrodes A, B, and C featured acicular ferrite and bainitic structure, while the original rail steel grade R260 possessed a pearlite matrix. The results showed that wear resistance did not correlate with hardness values. The wear resistance of the rail steel was highest, while its hardness was lowest. Covered electrode C, on the other hand, has the highest hardness but the lowest wear resistance. The worn surface of the repaired weld metal employing covered electrode A dominated micro-cutting mechanism. Micro ploughing and micro fracturing occurred in the weld metal of covered electrodes B and C during abrasion test. Therefore, covered electrode A performed best in this repair welding of R260 rail steel.
  • Publication
    Experimental analysis using thermocouple and infrared thermography of the temperature evolution of lithium-ion polymer cells at different charging rates
    (Springer, 2025)
    A. I. A. Sabandi
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    M. F. H. Rani
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    N. Maruyama
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    W. K. Wan
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    ; ;
    An experiment was designed to investigate the temperature revolution of lithium-ion polymer (LiPo) cells using two different approaches, thermocouples and infrared thermography. The cells were charged under controlled conditions at rates of 2.0 A, 4.0 A, 6.0 A, 8.0 A, and 10.0 A. The analysis focused on the maximum surface temperature, temperature changes over time, and surface temperature distribution. The findings revealed that higher charging rates result in increased heat generation, causing greater temperature rises, steeper temperature gradients, and higher maximum temperatures. During the charging process, the study also observed endothermic behavior and uneven temperature distribution across the cells. However, upon completing the charging, the surface temperature became evenly distributed without any critical hotspots. Notably, maximum temperatures were observed in the lower regions of the cells for lower charging rates (2.0 A, 4.0 A, and 6.0 A) and in the upper regions for higher rates (8.0 A and 10.0 A). Additionally, infrared thermography provided a clearer and more precise method for measuring surface temperatures compared to thermocouples, as indicated by experimental uncertainty analysis. IR imaging also showed a faster temperature increase at higher charging rates, offering deeper insights into the thermal characteristics of LiPo cells.
  • Publication
    Dispersion and tribological behaviors of modified functionalized surfaces of single and hybrid nanoparticles in water-based lubrication
    (Taylor and Francis Ltd., 2025)
    M. A. H. Azizan
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    M. S. Ibrahim
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    M. H. Sulaiman
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    Y. Yaakob
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    ;
    N. A. Sukindar
    This study investigated the dispersion and tribological effetcs of modifying surface functionalization on single (GO, Al₂O₃, MgO, SiC) and hybrid (SiC/MgO, Al₂O₃/MgO) nanoparticles in water-based lubricant (WBL) formulations. Polyvinylpyrrolidone (PVP) and glycerol were utilized to further enhance dispersion and viscosity. The experimental findings revealed that incorporating modified nanoparticles surfaces in WBLs improved hydrophilicity and dispersion by introducing additional oxygen functional groups. This effectively reduced direct metal-to-metal contact, resulting in lower interface temperatures and enhanced tribological performance. Hybrid Al₂O₃/MgO nanoparticles exhibited a significant 76.69 percent enhancement in tribological performance in wear mechanisms, synergistically filling microcracks to improve lubricant film formation, bearing, and mending effects. Using a single nanoparticle was found to be insufficient for achieving enhanced tribological effects. All nanoparticles improved bearing effects, except for GO, which promoted a shearing effect. High-hardness nanoparticles such as SiC and Al₂O₃ demonstrated an additional polishing effect.
  • Publication
    Effect of rubber sludge on the physical and mechanical properties of low calcium fly ash-based geopolymer
    (Polish Academy of Sciences, 2025)
    Tee Hoe Woon
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    ; ; ;
    Jia-Ni Lim
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    Ong Shee-Ween
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    O. Wan-En
    ;
    Hang Yong-Jie
    In this research, experimental work has been carried out to check the feasibility of using rubber sludge (RS) to partially replace fly ash (FA) in the production of geopolymer. RS is employed in this study as disposing of RS has led to an issue and is abundant, especially in countries producing rubber products. RS is classified as hazardous waste. Improper awareness on hazardous waste handling can spread a variety of diseases. Therefore, handling of hazardous waste is not easy as competent personnel is required during the collection, transportation, treatment and final disposal. As a result, the cost of disposing the hazardous waste are relatively high. With that, FA incorporated RS geopolymer will able to solve the landfill problems and used it as building materials will save costs, preserve natural resources, and protect the environment from waste impact and hazards. In this study, the physical and mechanical properties were investigated. It was used to replace fly ash at 5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%. Water absorption, apparent porosity, bulk density, and compressive strength were tested. The test result shows that 5 wt.% of RS incorporation to fly ash-based geopolymer is optimum as it has 1752 kg/m3 of density, 9.5% of water absorption, 19.2% of apparent porosity, and 49.9 MPa of compressive strength.