Khor Chu Yee
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Preferred name
Khor Chu Yee
Official Name
Khor, Chu Yee
Alternative Name
Yee, Khor Chu
Khor, Chu Yee
Khor, C. Y.
Yee, K. C
Main Affiliation
Scopus Author ID
57193315174
Researcher ID
B-1541-2014

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  • Publication
    Computational Fluid Dynamics Analysis of Varied Cross-Sectional Areas in Sleep Apnea Individuals across Diverse Situations
    ( 2024-01-01)
    Wan Mohd Faizal Wan Ab Rahim
    ;
    Khor Chu Yee
    ;
    Mohamad Suhaimi Shahrin
    ;
    Muhamad Nur Misbah
    ;
    Mohd. Hazwan Mohd. Hanid
    ;
    Masniezam Ahmad
    ;
    Mohd Haidiezul Jamal Ab Hadi
    Obstructive sleep apnea (OSA) is a common medical condition that impacts a significant portion of the population. To better understand this condition, research has been conducted on inhaling and exhaling breathing airflow parameters in patients with obstructive sleep apnea. A steady-state Reynolds-averaged Navier–Stokes (RANS) approach and an SST turbulence model have been utilized to simulate the upper airway airflow. A 3D airway model has been created using advanced software such as the Materialize Interactive Medical Image Control System (MIMICS) and ANSYS. The aim of the research was to fill this gap by conducting a detailed computational fluid dynamics (CFD) analysis to investigate the influence of cross-sectional areas on airflow characteristics during inhale and exhale breathing in OSA patients. The lack of detailed understanding of how the cross-sectional area of the airways affects OSA patients and the airflow dynamics in the upper airway is the primary problem addressed by this research. The simulations revealed that the cross-sectional area of the airway has a notable impact on velocity, Reynolds number, and turbulent kinetic energy (TKE). TKE, which measures turbulence flow in different breathing scenarios among patients, could potentially be utilized to assess the severity of obstructive sleep apnea (OSA). This research found a vital correlation between maximum pharyngeal turbulent kinetic energy (TKE) and cross-sectional areas in OSA patients, with a variance of 29.47%. Reduced cross-sectional area may result in a significant TKE rise of roughly 10.28% during inspiration and 10.18% during expiration.
      4  46
  • Publication
    The Effect of Different Waste Material Binders in Relation to Khaya Senegalensis Solid Fuel Pellet Quality
    ( 2023-11-01)
    Ras Izzati Ismail
    ;
    Khor Chu Yee
    ;
    Alina Rahayu Mohamed
    ;
    Mustafa N.M.K.N.
    ;
    Lee Yit Leng
    ;
    Nur Lailina Makhtar
    ;
    Norawanis Abdul Razak
    Fuel pellets are an attractive renewable energy source derived from biomass sources thanks to their uniformity and ease of handling. However, raw biomass and waste material binders have several drawbacks, which include poor physical properties, particularly low density and compositional heterogeneity, which restrict their wider use as a general source of energy. Besides, due to the low energy density, low bulk density, and uneven shape and size of raw biomass, it is very difficult to store and transport biomass in its original form, which decreases transport efficiency. This study investigated the effect of waste material binders (rice husk, corn cob, and sugarcane bagasse) on the mechanical and thermal properties of Khaya Senagalensis pellets. The mechanical and thermal properties were determined according to ASTM standards. Waste material binders have affected pellet quality such as density, bulk density, moisture content, durability, compressive strength, shatter index, water resistance, ash content, volatile matter, fixed carbon, and calorific value. From the analysis, sugarcane bagasse as a binder shows the highest quality pellet in terms of mechanical properties. Sugarcane bagasse produces the highest density (0.967g/cm3), bulk density (0.4094), durability (99.71%), shatter index (98.85%), water resistance (98.35%), and thermal properties, which are the highest volatile matter (94.71%) and the lowest ash content (1.71%). In a nutshell, sugarcane bagasse is a good binder that gives a positive impact to the K.senegalensis pellets in terms of storage and transportation compared to corn cob and rice husk binder.
      37  1
  • Publication
    The modified phase inversion and sintering technique for fabrication of ceramic membrane: Influence of kaolin composition and drying temperature
    ( 2021-05-03)
    Mohd Riduan Jamalludin
    ;
    Siti Nor Azreen Ahmad Termizi
    ;
    Khor Chu Yee
    ;
    Hubadillah S.K.
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Ishak M.I.
    ;
    Rosli M.U.
    The practical use of ceramic membrane has been limited by their fabrication technique and brittleness. Nowadays, phase inversion and sintering technique for ceramic membrane fabrication has been received widely attention. However, the unavoidable unstable structure for fabrication of flat-sheet ceramic membrane using this technique is still becoming an issue. To overcome this problem, in this paper, flat-sheet ceramic membrane have been developed via modified phase inversion and sintering technique using kaolin as main ceramic material, polyethersulfone (PESf) as the polymeric binder and N-methylpyyrolidone (NMP) as the solvent, respectively. The modified phase inversion has been done by adding drying process before the immersion into solvent. The influence of kaolin composition (60-80g) and drying temperature (room temperature and 3oC) have been investigated extensively to optimize the preparation. The results showed that the ceramic membrane prepared at 80g kaolin composition with drying temperature of 3oC displayed the highest bending strength of 53.1g with excellent BSA and humic acid rejection. Therefore, this study proved that the problem of unstable fabrication technique for flat-sheet ceramic membrane can be solved via modified phase inversion through the influence of high composition and low drying temperature.
      23  3
  • Publication
    Turbulent Kinetic Energy of Flow during Inhale and Exhale to Characterize the Severity of Obstructive Sleep Apnea Patient
    ( 2023-01-01)
    Wan Mohd Faizal Wan Nik
    ;
    Khor Chu Yee
    ;
    Yaakob M.N.C.
    ;
    Ghazali N.N.N.
    ;
    Zainon M.Z.
    ;
    Ibrahim N.B.
    ;
    Razi R.M.
    This paper aims to investigate and present the numerical investigation of airflow characteristics using Turbulent Kinetic Energy (TKE) to characterize the upper airway with obstructive sleep apnea (OSA) under inhale and exhale breathing conditions. The importance of TKE under both breathing conditions is that it show an accurate method in expressing the severity of flow in sleep disorder. Computational fluid dynamics simulate the upper airway’s airflow via steady-state Reynolds-averaged Navier-Stokes (RANS) with k–ω shear stress transport (SST) turbulence model. The three-dimensional (3D) airway model is created based on the CT scan images of an actual patient, meshed with 1.29 million elements using Materialise Interactive Medical Image Control System (MIMICS) and ANSYS software, respectively. High TKE were noticed around the region after the necking (smaller cross-sectional area) during the inhale and exhale breathing. The turbulent kinetic energy could be used as a valuable measure to identify the severity of OSA. This study is expected to provide a better understanding and clear visualization of the airflow characteristics during the inhale and exhale breathing in the upper airway of patients for medical practitioners in the OSA research field.
      1  20
  • Publication
    Mechanical and physical properties of khaya senegalensis solid fuel pellet with different binder percentages
    ( 2021-10-25)
    Ras Izzati Ismail
    ;
    Shaari A.R.
    ;
    Khor Chu Yee
    ;
    Alina Rahayu Mohamed
    ;
    Rahim M.S.b.A.
    ;
    Lee Yit Leng
    ;
    Wan Nur A'tiqah Wan Draman
    ;
    Nur Lailina Makhtar
    ;
    Norawanis Abdul Razak
    ;
    Mohd Riduan Jamalludin
    The characteristics of the solid fuel pellets, such as its strength, durability and density can be used to assess its quality. During the transport and storage, pellets with low strength and durability produces dusts and ultimately resulting in equipment blockage, high pollution emissions, and an increased risk of fire and explosion. Therefore, pellet manufacturing process should be given priority to improve pellet quality. The use of binder in the production of pellets will aid in improving pellet quality. Therefore, this study investigates the influence of different binder percentages on the mechanical properties of K. senegelensis fuel pellets. Durability, unit density, bulk density and diametral compressive strength testing were carried out in compliance with international standards. It was discovered that pellets containing 4% cassava starch binder produces better results, particularly in terms of durability and compressive ldiametral strength.
      37  1
  • Publication
    Production of Solid Biofuels From Renewable Resources: A Review
    ( 2023-06-09)
    Ras Izzati Ismail
    ;
    Khor Chu Yee
    ;
    Shaari A.R.
    ;
    Alina Rahayu Mohamed
    ;
    Abdul Halim M.H.B.
    ;
    Rahman A.A.A.
    ;
    Lee Yit Leng
    ;
    Nur Lailina Makhtar
    ;
    Norawanis Abdul Razak
    Increasing concerns over greenhouse gas emissions, volatile fossil fuel prices, and political instability have led to biomass as a renewable energy source. Close cooperation from the government supported by independent bodies also helps produce this effective and sustainable energy source. As a result, the current growth of solid biofuels has increased tremendously. Agricultural, municipal, forest, commercial waste and dedicated energy crops are the main sources of biomass. Due to this biomass's nature, the methods to produce them into solid biofuels are also different. The energy potential of these biomass sources is quite dependent on the use of technology and public awareness. Therefore, this paper review feedstock biomass, processing processes, product types and properties of solid biofuels in terms of mechanical and combustion. The paper also reviews the solid biofuel production situation in Malaysia.
      39  3
  • Publication
    Computational fluid dynamic study of the pharyngeal airway characteristics before and after mandibular setback surgery in patients with mandibular prognathism
    (Penerbit Akademia Baru, 2022-03-01)
    Aqilah N.
    ;
    Wan Mohd Faizal Wan Nik
    ;
    Khor Chu Yee
    ;
    Ghazali N.N.N.
    ;
    Zainon M.Z.
    ;
    Ismail M.A.
    Mandibular prognathism had been one of the most inconvenienced deformities developed in humans. This type of deformity possesses a protruded mandible jaw, and it can cause inconvenience in talking chewing and affect the aesthetic of the person diagnosed with this problem. However, this problem can be solved through mandibular setback surgery. This surgery will reposition the mandible jaw backward. The main concern of this surgery is, by repositioning the mandible jaw backward, the cross-sectional area of the airway will also be reduced. This condition might induce the iatrogenic of Obstructive Sleep Apnea (OSA). Thus, this study analyzed the characteristic of the pharyngeal airway in pre-treatment and post-virtual-operative conditions. This analysis simulates the pharyngeal airway with the Computational Fluid Dynamic (CFD) method. The respondent's data was obtained from computed tomography (CT) scan and was modeled into a 3-dimensional (3D) model. The simulation process takes place using the 3D model, mesh generation, and boundary conditions set-up. The flow pattern, pressure drop, airway wall shear stress, and turbulent kinetic energy were compared between both simulations. The simulations result present that, after the surgery, the pharyngeal airway decreases significantly. The pressure drop, flow pattern, airway wall shear stress (WSS), and turbulent kinetic energy (TKE) seem more significant around the critical plane in the post-treatment condition. However, these factors did not contribute to the OSA as it is not large enough to become the cause of OSA.
      3  7