Ahmad Nabil Mohd Khalil
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Preferred name
Ahmad Nabil Mohd Khalil
Official Name
Ahmad Nabil, Mohd Khalil
Alternative Name
Mohd Khalil, Ahmad Nabil
Main Affiliation
Scopus Author ID
57198904654
Researcher ID
AAF-8181-2019

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  • Publication
    Experimental Performance of R134a/SiO2 in Refrigeration System for Domestic Use
    (Penerbit Akademia Baru, 2022-01-01)
    Hussin M.H.C.
    ;
    Sa'adah Ahmad @ Ahmad Sowi
    ;
    Mahadi M.A.S.
    ;
    Sanuddin A.
    ;
    Ahmad Nabil Mohd Khalil
    ;
    Rahim Y.A.
    Nanofluids are considered as a new invention of fluids having superior thermal physical properties to improve efficiency of the refrigeration system. Nanofluids are the colloidal suspensions of nanoparticles in base fluid. Nanoparticles having higher thermal conductivity compared to pure refrigerant such as R134a can be added to pure refrigerant to improve the performance of refrigeration system. This study focuses on producing nanolubricant (SiO2/POE) and implementing the nanolubricant into refrigeration system. The nanoparticles will be homogenized in refrigerant to produce nanoRefrigerant (R134a/SiO2) at the attached reservoir. The aim of the research is to study the thermal physical properties of nanolubricant and to find the relationship between nanoparticles’ volume fraction to the Coefficient of Performance (COP) of the refrigeration system. The investigations are focused on the effects of nanoparticles with 0.1, 0.3%, 0.7% and 0.9% volume fraction to the performance of the refrigeration system. The results show that the usage of nanolubricant creates higher thermal conductivity with slightly higher dynamic viscosity which eventually increase the performance of the refrigeration system by 8.62% in term of COP.
      3  8
  • Publication
    The Effects of Self-Polymerized Polydopamine Coating on Mechanical Properties of Polylactic Acid (PLA)–Kenaf Fiber (KF) in Fused Deposition Modeling (FDM)
    ( 2023-06-01)
    Sanusi Hamat
    ;
    Syamir Alihan Showkat Ali
    ;
    Salit M.S.
    ;
    Yidris N.
    ;
    Showkat Ali S.A.
    ;
    Mohd Sabri Hussin
    ;
    Muhamad Saifuldin Abdul Manan
    ;
    Muhamad Qauyum Zawawi Ahamad Suffin
    ;
    Maliki Ibrahim
    ;
    Ahmad Nabil Mohd Khalil
    This research examines the impact of self-polymerized polydopamine (PDA) coating on the mechanical properties and microstructural behavior of polylactic acid (PLA)/kenaf fiber (KF) composites in fused deposition modeling (FDM). A biodegradable FDM model of natural fiber-reinforced composite (NFRC) filaments, coated with dopamine and reinforced with 5 to 20 wt.% bast kenaf fibers, was developed for 3D printing applications. Tensile, compression, and flexural test specimens were 3D printed, and the influence of kenaf fiber content on their mechanical properties was assessed. A comprehensive characterization of the blended pellets and printed composite materials was performed, encompassing chemical, physical, and microscopic analyses. The results demonstrate that the self-polymerized polydopamine coating acted as a coupling agent, enhancing the interfacial adhesion between kenaf fibers and the PLA matrix and leading to improved mechanical properties. An increase in density and porosity was observed in the FDM specimens of the PLA–PDA–KF composites, proportional to their kenaf fiber content. The enhanced bonding between kenaf fiber particles and the PLA matrix contributed to an increase of up to 13.4% for tensile and 15.3% for flexural in the Young’s modulus of PLA–PDA–KF composites and an increase of up to 30% in compressive stress. The incorporation of polydopamine as a coupling agent in the FDM filament composite led to an improvement in tensile, compressive, and flexural stresses and strain at break, surpassing that of pure PLA, while the reinforcement provided by kenaf fibers was enhanced more by delayed crack growth, resulting in a higher strain at break. The self-polymerized polydopamine coatings exhibit remarkable mechanical properties, suggesting their potential as a sustainable material for diverse applications in FDM.
      3  40
  • Publication
    Experimental Performance of R134a/SiO2 in Refrigeration System for Domestic Use
    ( 2022-01-01)
    Mohd Hisham Che Hussin
    ;
    Sa'adah Ahmad @ Ahmad Sowi
    ;
    Muhammad Adlin Syahar Mahadi
    ;
    Asmawi Sanuddin
    ;
    Ahmad Nabil Mohd Khalil
    ;
    Yuzairi Abdul Rahim
    Nanofluids are considered as a new invention of fluids having superior thermal physical properties to improve efficiency of the refrigeration system. Nanofluids are the colloidal suspensions of nanoparticles in base fluid. Nanoparticles having higher thermal conductivity compared to pure refrigerant such as R134a can be added to pure refrigerant to improve the performance of refrigeration system. This study focuses on producing nanolubricant (SiO2/POE) and implementing the nanolubricant into refrigeration system. The nanoparticles will be homogenized in refrigerant to produce nanoRefrigerant (R134a/SiO2) at the attached reservoir. The aim of the research is to study the thermal physical properties of nanolubricant and to find the relationship between nanoparticles’ volume fraction to the Coefficient of Performance (COP) of the refrigeration system. The investigations are focused on the effects of nanoparticles with 0.1, 0.3%, 0.7% and 0.9% volume fraction to the performance of the refrigeration system. The results show that the usage of nanolubricant creates higher thermal conductivity with slightly higher dynamic viscosity which eventually increase the performance of the refrigeration system by 8.62% in term of COP.
      1  28
  • Publication
    Thermophysical Properties of Molybdenum Disulfide (MoS2) and Aluminium Oxide (Al2O3) in Bio-based Coconut Oil Hybrid Nanolubricant for Cleaner Metalworking Cutting Fluid Applications
    ( 2023-06-01)
    Faudzi S.M.
    ;
    Ahmad Nabil Mohd Khalil
    ;
    Azwan Iskandar Azmi
    ;
    Sowi S.A.
    Green metalworking fluids have increasingly gained pivotal relevance as environmentally compatible lubricant with equivalent performance since conventional lubricant poses significant threat. This study performs experimental and theoretical discovery on the new approach to metalworking fluid; a bio-based coconut oil nanolubricant with hybrid nanoparticles of Al2O3/MoS2 regarding the thermophysical properties. The colloid was produced by suspending Al2O3 and MoS2 nanoparticles in coconut-based oil at different volumetric ratios of 1:1, 1:2, and 2:1 but equal volumetric concentrations of 0.3 vol%. The thermal conductivity of bio-based lubricants increased up to 4.3% with the addition of hybrid nanoparticles which was ascertained using KD2 Pro thermal analyzer. A contact angle goniometer was used to obtain the water drop profile and the maximum wettability of bio-based hybrid nanolubricant was obtained at 27.76° (Al2O3:MoS2 (1:1)) which indicates that incorporating both nanoparticles into the base system improved lubricant spreadability. The kinematic viscosity was evaluated through the viscometer and hybrid nanofluid possessed a remarkable increase in viscosity index of at least 49.6% (Al2O3:MoS2 (2:1)) among other samples. The stability test revealed that the nanolubricant (Al2O3:MoS2 (1:1)) was more stable than others. The experimental outcomes showed that the ratio of hybrid nanoparticles in base fluid has a significant role in enhancing thermophysical properties.
      1  28
  • Publication
    Roles of new bio-based nanolubricants towards eco-friendly and improved machinability of Inconel 718 alloys
    ( 2020-04-01)
    Ali M.A.M.
    ;
    Azwan Iskandar Azmi
    ;
    Muhamad Nasir Murad
    ;
    Mohd Zahiruddin Md. Zain
    ;
    Ahmad Nabil Mohd Khalil
    ;
    Norshah Aizat Shuaib
    The adverse effects of mineral oil-based metal cutting fluid on environmental sustainability have led to increased industrial concerns. Alternatively, biodegradable lubricants such as vegetable oil has a more positive impact with equivalent performance, but insufficient research on their benefits demands further exploration. This work features extensive experimental investigations on machining of Inconel 718 using novel formulations of coconut bio-based oil with enhanced nanoparticles and coco-amido-propyl-betaine. Bio-based with 0.8 wt% of Al2O3 managed to minimise the rapid growth of tool wear and prolong the tool life by 40.17%. Conversely, bio-based with 0.5 wt% of Al2O3 yielded lower values of cutting force (64.32 N), spindle power (2070 kW), specific cutting energy (6.55 W/mm3), and surface roughness (0.29 μm). The outstanding performance of bio-based nanolubricants contributed to superior machinability efficiency and eco-friendly machining environments.
      2  39