Mohd Al-Hafiz Mohd Nawi
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Preferred name
Mohd Al-Hafiz Mohd Nawi
Official Name
Mohd Al-Hafiz , Mohd Nawi
Alternative Name
Hafiz, M. A.
Nawi, M. A.H.M.
Nawi, M. A.M.
Nawi, Mohd Al Hafiz Mohd
Nawi, M. H.
Main Affiliation
Scopus Author ID
57195980205
Researcher ID
IOU-7551-2023

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  • Publication
    Effect of twist blade distributor on velocity distribution in a swirling fluidized bed
    ( 2020-12-18)
    Mohd Al-Hafiz Mohd Nawi
    ;
    Ishak M.I.
    ;
    Rosli M.U.
    ;
    Suhaida Rasman S.N.
    ;
    Mohd Riduan Jamalludin
    ;
    Siti Nor Azreen Ahmad Termizi
    ;
    Khor Chu Yee
    Swirling Fluidized Bed (SFB) is one of the liquid-solid interaction in fluidization improved from conventional systems. This system is usually viewable in the power generation, chemical industry, material production and drying processes. Inside the SFB, there is annular blade distributor which will cause the air to pass through and create a swirl motion on the bed. The energy consumption of a fluidized bed system depends on the distributor's design. The current study has purpose a new design that applies to existing designs of blade inclination angle. The simulation study was conducted using Computational Fluid Dynamics (CFD) to obtain the result of velocity distribution and pressure drops on various blade distributor designs. This study uses two (2) twist angle (80 and 100 ) via number of blade distributor (40, 50 and 60). In this study, tangential velocity is the main velocity component by reason of the velocity represents the rotating air velocity in fluidization system. Overall, the design of the 100 twist angle and 40 blades distributor are the best distributors of blades compared to others.
  • Publication
    Simulation Analysis of the Thickness Effect towards Mechanical Aspects in the Design of Centrifugal Pump Casing
    ( 2020-07-09)
    Khor Chu Yee
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Muhammad Ikman Ishak
    ;
    Ooi Z.K.
    ;
    Mohd Uzair Mohd Rosli
    ;
    Siti Nor Azreen Ahmad Termizi
    The strength of the centrifugal pump is crucial to ensure the safe pump operating when endure to unintended pumping condition. The presence of the solid particles and sudden increase of pressure may lead to the damage on the casing of a centrifugal pump and it becomes critical when the thickness of the casing is thin. This study aims to investigate the effects of the thickness on the mechanical aspects such as stress, strain and displacement in the casing design by using finite element (FE) analysis. The structure of the pump casing with various thicknesses is analyzed via FE-based software. The correlation of the wall thickness with the mechanical aspects is studied. The critical region with high stress was spotted in the simulation. The simulation results revealed the wall thickness demonstrated a polynomial correlation to the displacement and strain. The stress of the casing showed the linear correlation with the thickness. The critical region was noticed at the intersection region of the pump casing. The mechanical aspects of the pump casing were improved with the increment of the wall thickness in the pump casing design.
  • Publication
    5.8 GHz Circularly Polarized Rectangular Microstrip Antenna Arrays simulation for Point-to-Point Application
    ( 2022-11-01)
    Mohd Aminudin Jamlos
    ;
    Sabri N.H.M.
    ;
    Jamlos M.F.
    ;
    Wan Azani Wan Mustafa
    ;
    Syed Zulkarnain Syed Idrus
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Khairul Najmy Abdul Rani
    ;
    Mohd Al-Hafiz Mohd Nawi
    In this paper, the design and simulation of rectangular microstrip antenna arrays for improving antenna gain is performed for point-to-point application. The circular polarization is proposed to restrict the limitation of linear polarization which is less reliable in base station antenna. The circular polarization antenna is made to allow the receiver constantly to receive the power at any wave angle and make the transmission between two antennas are more constant. The proposed design is composed of four elements microstrip antenna with an array configuration operating at 5.8 GHz. Each element is constructed from four truncated arrays radiating elements and an inclined slot on each patch which capable to achieve circular polarized capability. The design of the 2x1 and 2x2 of rectangular microstrip array antenna was implemented from the design of single rectangular patch antenna as the basic building element. The designed 2x1 and 2x2 array were fed by microstrip transmission line which applied a technique of quarter wave impedance matching. The antenna design was etched on Rogers RT 5880 substrate with 2.1 and 1.53 mm of dielectric constant and thickness respectively. All the designed structure were simulated in CST software. The main results of the designed antennas were compared in terms of gain, axial ratio and return loss. Based on the return loss simulation results, the designed antennas resonated exactly at the desired resonant frequency of 5.8 GHz which indicates good antenna designs. Compared to the single patch antenna having an antenna gain of 8.26 dB, the 2x1 and 2x2 arrays achieved a gain of 10.24 dB and 13.29 dB respectively. The results show that the designed rectangular microstrip antenna arrays have an improved gain performance over the single patch antenna.
  • Publication
    Effect of zinc addition on the performance of aluminium alloy sacrificial anode for marine application
    ( 2017-09-26)
    Khan B.
    ;
    Rosli M.U.
    ;
    Hazrin Jahidi Jaafar
    ;
    Muhammad Ikman Ishak
    ;
    Muhammad Syamil Zakaria
    ;
    Mohd Riduan Jamalludin
    ;
    Khor Chu Yee
    ;
    Wan Mohd Faizal Wan Ab Rahim
    ;
    Rahim W.M.
    ;
    Mohd Al-Hafiz Mohd Nawi
    In this work, the effect of zinc addition on the performance of aluminum-based sacrificial anode in seawater was investigated. The parameters used in assessing the performance of the cast anodes are anodic efficiency, protection efficiency and polarized potential. The content of zinc in the anodes was varied after die casting. The alloys produced were tested as sacrificial anode for the protection of mild steel for marine application at room temperature. Factors such as reactivity of zinc particles in the seawater, corrosion activity during the period of experiment, pH of seawater and the electronegativity potential of zinc were collected for analysis. Overall findings shows addition of zinc increases rate of corrosion to the sacrificial anode and the protection offered by the sacrificial anodes measured and collected in PIT shows the seawater react to sacrificial anode and no porosity reaction between the anodes. The microstructure showed the intermetallic structures of β-phase which breakdown the alumina passive film, thus enhancing the anode efficiency.
  • Publication
    A Short Review on Multi-stage Application in Fluidization Systems
    ( 2021-01-01)
    Silmie M.S.M.
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Ishak M.I.
    ;
    Rosli M.U.
    ;
    Siti Nor Azreen Ahmad Termizi
    ;
    Khor Chu Yee
    ;
    Faris M.A.
    ;
    Marzuki M.A.B.
    This research focuses on the implementation of an approach of multi-stage in fluidization systems in various aspects. The multi-stage fluidized bed has been proposed to improve the process and function of fluidization systems based on the current of the single-stage methods. The detailed of single-stage fluidization interaction method provides a realistic visualization of airflow and fluidization system interaction. In this article, a variant application, involving in multi-stage fluidized bed has been reviewed. In a few articles were analyzed, each manuscript was evaluated based on the scientific work via fluidization systems. The experimental study and analysis of airflow characteristics was a valuable tool to understand this phenomenon of the multi-stage fluidized bed process. Then the parameter, flow properties, activities of the multi-stage fluidized bed systems have been considered to the current swirling fluidized bed being applied to study. As a result of this short review, each multi-stage fluidized bed has its capability and suitability for its products and studies. Finally, the concentration of multi-stage fluidized bed is also highlighted in these manuscripts.
  • Publication
    Numerical Simulation of Biodiesel Synthesis in T- Channel Microreactor
    ( 2020-07-09)
    Siti Nor Azreen Ahmad Termizi
    ;
    Khor Chu Yee
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Syafiqah Binti Mohd Aris N.
    ;
    Muhammad Ikman Ishak
    ;
    Rosli M.U.
    Biodiesel promising as an alternative to the diesel. The transesterification reaction process involved the reaction of triglyceride with alcohol in the presence of catalyst. In the research, the Computational Fluid Dynamic (CFD) method was used to simulate the transesterification reaction process. The inlet pressure range from 0.0001 Pa to 0.01 Pa, temperature of 25°C, 50°C, 75°C and the molar ratio at 6:1, 9:1 were used to investigate their effect of toward the biodiesel conversion. Finding shows that high conversion of biodiesel occurred at low inlet pressure of 0.001 Pa with temperature of 50°C and the ethanol to oil molar ratio at 9:1.
  • Publication
    Reduced Graphene Oxide UWB Array Sensor: High Performance for Brain Tumor Imaging and Detection
    ( 2023-01-01)
    Mohd Aminudin Jamlos
    ;
    Jamlos M.F.
    ;
    Wan Azani Wan Mustafa
    ;
    Othman N.A.
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Syahrul Affandi Saidi
    ;
    Mohd Sharizan Md Sarip
    ;
    Mohd Al-Hafiz Mohd Nawi
    A low cost, with high performance, reduced graphene oxide (RGO) Ultra-wide Band (UWB) array sensor is presented to be applied with a technique of confocal radar-based microwave imaging to recognize a tumor in a human brain. RGO is used to form its patches on a Taconic substrate. The sensor functioned in a range of 1.2 to 10.8 GHz under UWB frequency. The sensor demonstrates high gain of 5.2 to 14.5 dB, with the small size of 90 mm × 45 mm2, which can be easily integrated into microwave imaging systems and allow the best functionality. Moreover, the novel UWB RGO array sensor is established as a detector with a phantom of the human head. The layers’ structure represents liquid-imitating tissues that consist of skin, fat, skull, and brain. The sensor will scan nine different points to cover the whole one-sided head phantom to obtain equally distributed reflected signals under two different situations, namely the existence and absence of the tumor. In order to accurately detect the tumor by producing sharper and clearer microwave image, the Matrix Laboratory software is used to improve the microwave imaging algorithm (delay and sum) including summing the imaging algorithm and recording the scattering parameters. The existence of a tumor will produce images with an error that is lower than 2 cm.
  • Publication
    Computational fluid dynamics (CFD) simulation on mixing in Y-shaped micromixer
    ( 2020-11-02)
    Siti Nor Azreen Ahmad Termizi
    ;
    Ishak M.I.
    ;
    Khor Chu Yee
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Pouzay M.F.B.M.
    Computational Fluid Dynamics (CFD) is used to analyse the mixing process inY-shaped micromixer. This study used two different species which is ethanol/water and glycerol/water to see the differences of mixing quality between them based on their diffusion coefficient. The effect of the inlet velocity and mixing angle towards the mixing intensity in the Y-shaped micromixer were investigated via COMSOL Multiphysics software. Mixing intensity quantify the mixing performance is good or bad for every parameter simulated. The finding shows that the lower the inlet velocity, the higher the mixing intensity across the micromixer. The good mixing quality was at inlet velocity of 0.0001m/s while the ideal mixing angle was 90° degree. However, the mixing quality in term of diffusion coefficient, ethanol/water and glycerol/water shows insignificant differences.
  • Publication
    Effect of Nozzle Diameter on Temperature Behavior in Spray Dryer Via Computational Fluid Dynamics
    ( 2022-01-01)
    Mohammad Azrul Rizal Alias
    ;
    Mohd Sharizan Md Sarip
    ;
    Wan Azani Wan Mustafa
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Yang L.W.
    ;
    Samat A.A.
    ;
    Raja Ibrahim R.M.Z.
    ;
    Shabri M.S.M.
    Spray dryer comes at the end of the processing line since it is a critical step in monitoring the quality of the final product. It has certain advantages such as rapid drying rates, a wide range of operating temperatures and short residence times. This research focuses on the effect of inlet air temperature in the spray dryer chamber. The result from previous studies has shown that the increment of the inlet air temperature has caused the dying rate to increase. From the simulation, we have identified the performance in the spray dryer with different inlet air temperature as the parameter. The higher the inlet air temperature, the less the number of incomplete particles inside the spray dryer chamber, the more the success of the drying particles. The most optimized condition of inlet air temperature inside the spray dryer chamber from different parameters was identified as 225 K after the analysis on the results of simulation data. The main impact of this study is to increase the efficiency of drying particles inside the spray dryer chamber via computational fluid dynamics. In conclusion, researchers should concentrate more on the feed inlet air temperature of spray drying for future analysis because it plays an important role that can influence the impact on droplet conversion.