Mohd Fathullah Ghazli@Ghazali
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Mohd Fathullah Ghazli@Ghazali
Official Name
Mohd Fathullah, Ghazli@Ghazali
Alternative Name
Fathullah, Mohd
Ghazli, Mohd
Ghazli, M. F.
Ghazali, Mohd Fathullah
Fathullah, G. M.
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Scopus Author ID
57428935900
Researcher ID
AAK-5597-2020

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Effect of tool engagement on cutting force for different step over in milling aisi p20 tool steel

2021-01-01 , Roshaliza Hamidon , Mohamed N.I. , Saravanan R. , Azmi H. , Zailani Zainal Abidin , Mohd Fathullah Ghazli@Ghazali

In mold production, end milling with tool path strategies is required for the process known as pocket operation. Different step overs involve depending on the type of tool path strategy used. Thus, different engagement will occur and leads to fluctuation of cutting force due to different step over during the process. However, most of study before focused on the effect of cutting speed, feed rate and depth of cut only in machining AISI P20. Thus, in this study, step over will be considered as one of the factor to improve machining force. The objective of this study are to evaluate the effect of cutting parameters and step over on cutting force and to study the behavior of cutting force for different tool engagement. A series of milling operation was carried out by varying cutting speed and feed rate. However, the depth of cut was set to 0.25 mm for each run. Step over with 100%, 75% and 50% were selected in this study. L27 Taguchi and S/N ratio were used to determine the significant factors that influence the result. Within the range of cutting parameters selected, feed rate were found to be the most significant parameters that influence cutting force. The highest cutting force found for 100% step over compared to 75% and 50% step over. According to the result, cutting force increased as the step over increased. In can be concluded that, step over is one of the important cutting parameter that affected machining output.

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Optimisation of shrinkage and strength on thick plate part using recycled LDPE materials

2021 , Norshahira Roslan , Shayfull Zamree Abd. Rahim , Abdellah El-hadj Abdellah , Mohd. Mustafa Al Bakri Abdullah , Katarzyna Błoch , Paweł Pietrusiewicz , Marcin Nabiałek , Janusz Szmidla , Dariusz Kwiatkowski , Joel Oliveira Correia Vasco , Mohd. Nasir Mat Saad , Mohd Fathullah Ghazli@Ghazali

Achieving good quality of products from plastic injection moulding processes is very challenging, since the process comprises many affecting parameters. Common defects such as warpage are hard to avoid, and the defective parts will eventually go to waste, leading to unnecessary costs to the manufacturer. The use of recycled material from postindustrial waste has been studied by a few researchers. However, the application of an optimisation method by which to optimise processing parameters to mould parts using recycled materials remains lacking. In this study, Response Surface Methodology (RSM) and Particle Swarm Optimisation (PSO) methods were conducted on thick plate parts moulded using virgin and recycled low-density polyethylene (LDPE) materials (100:0, 70:30, 60:40 and 50:50; virgin to recycle material ratios) to find the optimal input parameters for each of the material ratios. Shrinkage in the x and y directions increased in correlation with the recycled ratio, compared to virgin material. Meanwhile, the tensile strength of the thick plate part continued to decrease when the recycled ratio increased. R30 (70:30) had the optimum shrinkage in the x direction with respect to R0 (100:0) material where the shrinkage increased by 24.49% (RSM) and 33.20% (PSO). On the other hand, the shrinkage in the y direction for R30 material increased by 4.48% (RSM) and decreased by 2.67% (PSO), while the tensile strength of R30 (70:30) material decreased by 0.51% (RSM) and 2.68% (PSO) as compared to R0 (100:0) material. Validation tests indicated that the optimal setting of processing parameter suggested by PSO and RSM for R0 (100:0), R30 (70:30), R40 (60:40) and R50 (50:50) was less than 10%.

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Warpage optimisation using recycled Polycar-bonates (PC) on front panel housing

2021 , Nur Aisyah Miza Ahmad Tamizi , Shayfull Zamree Abd. Rahim , Abdellah El-hadj Abdellah , Mohd. Mustafa Al Bakri Abdullah , Marcin Nabiałek , Jerzy J. Wysłocki , Bartłomiej Jeż , Paweł Palutkiewicz , Rozyanty Abdul Rahman , Mohd. Nasir Mat Saad , Mohd Fathullah Ghazli@Ghazali

Many studies have been done using recycled waste materials to minimise environmental problems. It is a great opportunity to explore mechanical recycling and the use of recycled and virgin blend as a material to produce new products with minimum defects. In this study, appropriate processing parameters were considered to mould the front panel housing part using R0% (virgin), R30% (30% virgin: 70% recycled), R40% (40% virgin: 60% recycled) and R50% (50% virgin: 50% recycled) of Polycarbonate (PC). The manufacturing ability and quality during preliminary stage can be predicted through simulation analysis using Autodesk Moldflow Insight 2012 software. The recommended processing parameters and values of warpage in x and y directions can also be obtained using this software. No value of warpage was obtained from simulation studies for x direction on the front panel housing. Therefore, this study only focused on reducing the warpage in the y direction. Response Surface Methodology (RSM) and Genetic Algorithm (GA) optimisation methods were used to find the optimal processing parameters. As the results, the optimal ratio of recycled PC material was found to be R30%, followed by R40% and R50% materials using RSM and GA methods as compared to the average value of warpage on the moulded part using R0%. The most influential processing parameter that contributed to warpage defect was packing pressure for all materials used in this study.

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Prediction of Selected Water Quality and Macronutrients Parameters in an Aquaponic System Using Artificial Neural Network (ANN)

2023-01-01 , Osman M.S. , Abdul Rahman Q.K. , Setumin S. , Maruzuki M.I.F. , Senin S.F. , Nizam M.I. , Mohd Fathullah Ghazli@Ghazali , Nazeri N.B.M. , Akbar M.S.

Aquaponics, essentially incorporates multiple aquaculture and hydroponics into a single closed-loop system, is an excellent alternative method for generating reduced environmental waste by recycling nutrients (fish waste) for crop development. The pH, dissolved oxygen (DO), total ammoniacal nitrogen (TAN), and total percentage sludge of phosphorus (P) and nitrogen (N) of empirical experiments obtained from the aquaponic system have been investigated (N). To obtain the predicted value, an artificial neural network (ANN) modelling function employing the Levenberg–Marquardt (LM) and scaled conjugate gradient (SCG) training functions was utilized in this research. The outputs of the training function model suggested the optimal number of neurons for each pH parameter, DO, and TAN for neurons 6, respectively. In terms of total sludge (nitrogen and phosphorus), the optimal number of neurons is three. On the other hand, the most optimum neuron number at neurons 4 for parameters pH, DO, and TAN, while for the SCG training function was the most optimal neuron number is 4 for the total sludge parameter (N and P), respectively. Meanwhile, in trained neural network’s evaluated prediction parameters accuracies, LM outperformed SCG in terms of correlation coefficient (R) and Mean Square Error (MSE).

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Feasibility of Multilayer Perceptron (MLP) Network to Correlate Air Quality Index (AQI) and COVID-19 Daily Cases

2023-01-01 , Abd Maruzuki M.I.F. , Tengku Zahidi T.S.A. , Khairudin K. , Osman M.S. , Jasmy N.F. , Abdul Hadi B. , Akbar M.S. , Saufie A.Z.U. , Mohd Fathullah Ghazli@Ghazali , Nor Syamsudin D.S. , Mohd Nazeri N.B.

A movement control order (MCO) was implemented in Malaysia starting from March 18th, 2020, as a pandemic control strategy that restricted all movement and daily outdoor activities to curb the transmission of COVID-19 pandemic. The most populated area in Malaysia, Petaling Jaya, Selangor, was selected to investigate the relationship between the COVID-19 outbreak and air pollution. Multilayer perceptron (MLP) model was used in this study to correlate air quality index (AQI) with COVID-19-related cases/deaths. The underlying hypothesis is that a pre-determined particulate concentration can encourage COVID-19 airborne transmission and make the respiratory system more susceptible to this infection. The in-silico strategy employed an innovative machine learning (ML) methodology, specifically MLP network using AQI data from the Department of Environment (DOE), Malaysia as input data and number of COVID-19 cases from the Ministry of Health, Malaysia as target data. The MLP model was trained for 10,000 times. Based on the results obtained, the model starts to converge after 1000 epochs with a small mean absolute error (MAE) (173.0–118.9) from day 1 to day 14. However, there is no definitive correlation between predicted COVID-19 patients and the AQI with respect to day configuration.

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P-nitrophenol degradation by gold nanoparticles augmented cellulosic microcapsules: Influence of catalyst dosage, reaction temperature and kinetic analysis

2023-03-23 , Osman M.S. , Fadzil S.S. , Khairudin K. , Bashah N.A.A. , Mohd Fathullah Ghazli@Ghazali , Nasrudin N.A.

For the parametric research of P-nitrophenol degradation (PNP) performance, the alginate encapsulating method was used to improve gold nanoparticles using cellulosic microcapsules. The goals are to investigate the gold nanoparticles's kinetic model in the degradation of PNP using UV-Vis spectrometry and to determine the parametric of the effect of AuNP-cellulose catalyst dose on efficiency of its removal and the role of AuNP-cellulose in PNP degradation at a variation of temperatures. The gold nanoparticle was formulated by reducing citrate technique and synthesised with coconut husk cellulose before being transformed into microcapsules and then formed into AuNP-cellulosic microcapsule beads. An excess quantity of sodium borohydride, NaBH4, was used as a model reaction to assess the catalytic performance of AuNPs for the reduction of PNP. The quantities of AuNP-cellulose catalyst have been weighted at 5, 7, and 10 mg for the dose of AuNP-cellulose catalyst on PNP elimination efficiency. With a 10 mg catalyst dose, the maximum PNP removal rate of 96.1 percent is achieved. When AuNP-cellulose reactions in degrading PNP are compared at different temperatures (28°C, 35°C, 45°C, and 55°C), the degradation is quicker at 55°C, taking just 5 minutes. The catalytic system's activation energy (Ea) for PNP degrading into PAP is 13.63 kJ/mol. This research indicates that as the catalyst dose is raised, the removal efficiency improves, and high temperatures accelerate PNP decrease.

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Morphological Characterization of Silver Nanowires (AgNWs)-Embedded Polymeric Film for Flexible Wearable Antenna

2023-01-01 , Osman M.S. , Abd Halim N.H. , Khairudin K. , Abu Bakar A. , Razali A.R. , Mohd Fathullah Ghazli@Ghazali , Abdul Razak A.K. , Akbar M.S.

Silver nanowires (AgNWs) transparent electrodes have recently been selected as an alternative conductor for use in various electronic devices. The synthesis of AgNWs for a flexible wearable antenna is successfully demonstrated on PDMS/PVDF elastomeric substrate. In order to consider its suitability for use in flexible antenna applications, the structural properties of AgNWs-polymeric film are discussed. This type of flexible antenna is prepared using the casting method by embedding the AgNWs on the surface of the PDMS/PVDF elastomeric substrate. Analysis of FTIR and SEM showed that AgNWs are reliably transferred to the elastomeric substratum surface, which then served as a conductive radiating factor for the antenna system. Uniform average porosity suggested sponge formation as a porous structure on the film surface that is beneficial for the AgNWs catchment area. The as-made AgNWs-polymeric substrate revealed antennas shaped âˆ’ 18 dB return loss with a frequency of 2.725 GHz. These results have shown the feasibility of this AgNWs’ polymer film in wireless communications’ applications for wearable systems.

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Optimisation of warpage on plastic injection moulding part using response surface methodology (RSM) and genetic algorithm method (GA)

2017-09-26 , Miza A.T.N.A. , Shayfull Zamree Abd. Rahim , Mohd. Nasir Mat Saad , Mohd Fathullah Ghazli@Ghazali , Mohd. Hazwan Mohd. Hanid

In this study, Computer Aided Engineering was used for injection moulding simulation. The method of Design of experiment (DOE) was utilize according to the Latin Square orthogonal array. The relationship between the injection moulding parameters and warpage were identify based on the experimental data that used. Response Surface Methodology (RSM) was used as to validate the model accuracy. Then, the RSM and GA method were combine as to examine the optimum injection moulding process parameter. Therefore the optimisation of injection moulding is largely improve and the result shown an increasing accuracy and also reliability. The propose method by combining RSM and GA method also contribute in minimising the warpage from occur.

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HIRARC assessment on a catering worker: A case study

2023-04-24 , Mohd Fathullah Ghazli@Ghazali , Osman M.S. , Darmawan V.E.B. , Shahrolnizam M.A.F. , Muslim M.M. , Wasa T.A.T.A. , Ramli Y.N.

The costs and effects of twenty workplace accidents are reported in this report. The research was commissioned by the Health and Safety Authority and conducted by an institution in 2007. The purpose of the scientific research was to explore the impact of workplace accidents using a case study approach. The results are intended to enrich the prior quantitative studies provided by the Health and Safety Authority and to inform the Authority of future promotional campaigns. The methodological objective was to detect the financial, physical and psychological consequences that accidents at work may have for employers and employees. The technique involved interviewing and presenting the results as case studies of the injured staff and their employers (or agents).

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Comparison of hook and straight steel fibers addition on malaysian fly ash-based geopolymer concrete on the slump, density, water absorption and mechanical properties

2021 , Meor Ahmad Faris bin Meor Ahmad Tajudin , Mohd. Mustafa Al Bakri Abdullah , Ratnasamy Muniandy , Mohammad Firdaus Abu Hashim , Katarzyna Błoch , Bartłomiej Jeż , Sebastian Garus , Paweł Palutkiewicz , Nurul Aida Mohd Mortar , Mohd Fathullah Ghazli@Ghazali

Geopolymer concrete has the potential to replace ordinary Portland cement which can reduce carbon dioxide emission to the environment. The addition of different amounts of steel fibers, as well as different types of end-shape fibers, could alter the performance of geopolymer concrete. The source of aluminosilicate (fly ash) used in the production of geopolymer concrete may lead to a different result. This study focuses on the comparison between Malaysian fly ash geopolymer concrete with the addition of hooked steel fibers and geopolymer concrete with the addition of straight-end steel fibers to the physical and mechanical properties. Malaysian fly ash was first characterized by X-ray fluorescence (XRF) to identify the chemical composition. The sample of steel fiber reinforced geopolymer concrete was produced by mixing fly ash, alkali activators, aggregates, and specific amounts of hook or straight steel fibers. The steel fibers addition for both types of fibers are 0%, 0.5%, 1.0%, 1.5%, and 2.0% by volume percentage. The samples were cured at room temperature. The physical properties (slump, density, and water absorption) of reinforced geopolymer concrete were studied. Meanwhile, a mechanical performance which is compressive, as well as the flexural strength was studied. The results show that the pattern in physical properties of geopolymer concrete for both types of fibers addition is almost similar where the slump is decreased with density and water absorption is increased with the increasing amount of fibers addition. However, the addition of hook steel fiber to the geopolymer concrete produced a lower slump than the addition of straight steel fibers. Meanwhile, the addition of hook steel fiber to the geopolymer concrete shows a higher density and water absorption compared to the sample with the addition of straight steel fibers. However, the difference is not significant. Besides, samples with the addition of hook steel fibers give better performance for compressive and flexural strength compared to the samples with the addition of straight steel fibers where the highest is at 1.0% of fibers addition.

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