Ahmad Nabil Mohd Khalil
Thumbnail Image
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

Research Output

Filters

4
7
Reset filters

Settings
Now showing 1 - 7 of 7
Thumbnail Image
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.

View
Thumbnail Image
Publication

The effect of semi-conductive and non-conductive nano particles in sunflower oil based insulation

2020-01-07 , Nuriziani Hussin , Kwong Yeaw L. , Ahmad Nabil Mohd Khalil , Kamarol Mohd Jamil M. , Norkharziana Mohd Nayan , Syahrun Nizam Md Arshad @ Hashim , Ainanie Azizie N.

Following the improvement of technology, more and more alternatives are introduced to improve the insulation material and one of them is the nanotechnology. Research had been done which confirm the enhancement of the transformer oil upon adding nanoparticles in term of dielectric strength, viscosity, relative permittivity and others. In this research, semi-conductive (ZnO) and non-conductive (ZrO2) nanoparticles with weigh to volume ratio of 0.05g/l are added to the sunflower oil based insulation and the effects are observed. The relative permittivity of added ZnO is higher compare to ZrO2 in mineral oil. The situation is opposite as ZrO2 yield higher permittivity with sunflower oil. In term of breakdown voltage, the addition of ZnO shows a better dielectric strength compare to ZrO2. The kinematic viscosity is also increase when both nanoparticles are added in which ZnO contributes a higher value.

View
Thumbnail Image
Publication

A study of energy consumption in turning process using lubrication of nanoparticles enhanced coconut oil (NECO)

2017-10-29 , Ahmad Fairuz Mansor , Muhammad Syamil Zakaria , Azwan Iskandar Azmi , Ahmad Nabil Mohd Khalil , Musa N.A.

Cutting fluids play very important role in machining application in order to increase tool life, surface finish and reduce energy consumption. Instead of using petrochemical and synthetic based cutting fluids, vegetable oil based lubricants is safety for operators, environmental friendly and become more popular in the industrial applications. This research paper aims to find the advantage of using vegetable oils (coconut oil) with additional of nano particles (CuO) as lubricant to the energy consumption during machining process. The energy was measured for each run from 2 level factorial experimental layout. Obtained results illustrate that lubricant with enhancement of nanoparticles has capability to improve the energy consumption during the machining process.

View
Thumbnail Image
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.

View
No Thumbnail Available
Publication

Perturbation parameters tuning of multi-objective optimization differential evolution and its application to dynamic system modeling

2015 , Mohd Zakimi Zakaria , Hishamuddin Jamaluddin , Robiah Ahmad , Azmi Harun , Radhwan Hussin , Ahmad Nabil Mohd Khalil , Muhammad Khairy Md Naim , Ahmad Faizal Annuar

This paper presents perturbation parameters for tuning of multi-objective optimization differential evolution and its application to dynamic system modeling. The perturbation of the proposed algorithm was composed of crossover and mutation operators.  Initially, a set of parameter values was tuned vigorously by executing multiple runs of algorithm for each proposed parameter variation. A set of values for crossover and mutation rates were proposed in executing the algorithm for model structure selection in dynamic system modeling. The model structure selection was one of the procedures in the system identification technique. Most researchers focused on the problem in selecting the parsimony model as the best represented the dynamic systems. Therefore, this problem needed two objective functions to overcome it, i.e. minimum predictive error and model complexity.  One of the main problems in identification of dynamic systems is to select the minimal model from the huge possible models that need to be considered. Hence, the important concepts in selecting good and adequate model used in the proposed algorithm were elaborated, including the implementation of the algorithm for modeling dynamic systems. Besides, the results showed that multi-objective optimization differential evolution performed better with tuned perturbation parameters.

View
Thumbnail Image
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.

View
Thumbnail Image
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.

View