Cheng Ee Meng
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Cheng Ee Meng
Official Name
Cheng, Ee Meng
Alternative Name
Cheng, E. M.
Cheng, Ee M.
Cheng, Ee Meng
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Scopus Author ID
57219023469
Researcher ID
IOQ-9149-2023

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  • Publication
    Formation of bio-based derived dicalcium silicate ceramics via mechanochemical treatment: physical, XRD, SEM and FTIR analyses
    ( 2023-07)
    Siti Nur Hazwani Yunus
    ;
    Khor Shing Fhan
    ;
    Banjuraizah Johar
    ;
    Nur Maizatul Shima Adzali
    ;
    Nur Hazlinda Jakfar
    ;
    Cheng Ee Meng
    ;
    Emma Ziezie Mohd Tarmizi
    ;
    Zainal Abidin Talib
    Beta-dicalcium silicate plays an important role in modern technology, but its tendency for polymorphic transformation results in the dusting phenomenon, is a major challenge. Therefore, mechanochemical treatment is used to reduce the particle size to retain the stability of the polymorph. In this study, pure dicalcium silicate ceramics of β-monoclinic structure with P 121/c1 space group were synthesized using calcium oxide and silicate powders derived from calcined eggshells and rice husks, respectively. The powders were mixed in a 2:1 molar ratio by mechanochemical treatment and heat-treated in the air at temperatures ranging from 900°C to 1100°C for 2 h. The results reveal that pure betadicalcium silicate formed at 1100°C without adding stabilizers. The properties of the pristine and sintered bodies were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). SEM revealed that the grain and pore sizes increase with rising sintering temperatures. FTIR spectra indicate the existence of Si-O bonds in -4 4 SiO tetrahedrons on all the samples. The sample sintered at 1000°C attains the lowest bulk density (1.2463 g/cm3), whereas the apparent porosity is the highest (62.5%). The reason for this trend is due to the decomposition of carbonate into CO2 gas. The densification onset for the sample sintered at 1100°C as the bulk density rises and grain size achieves 6.06 μm. This study further explains the effect of sintering temperatures on the physical, structural, and morphological properties of Ca2SiO4 which would also be useful for further optimization of its use.
  • Publication
    In-situ Noise Measurement and Analysis for the Motorcycle Muffler
    ( 2020-01-01)
    Tan Wei Hong
    ;
    Chuah H.G.
    ;
    Cheng Ee Meng
    ;
    Lim Eng Aik
    ;
    Lok, Chip Hao
    Noise from the vehicles is one of the noise pollutions to the environment. The noises emitted by the vehicles have to obey the requirement of regulation of maximum sound pressure level permitted for respective vehicles. In this study, the aim is to reduce the noise emitted from the motorcycle muffler. The noise emitted from the motorcycle muffler is analyzed and measured using a sound level meter. The average sound pressure level of the motorcycle muffler is determined in certain conditions. The sound pressure levels for original installed muffler are recorded as 76.4dB, 79.5dB and 82.3dB under the constant speed of 10km/hr, 20km/hr and 30km/hr respectively by engaging 2nd gear. For the acceleration with the scope of 0 km/hr to 30 km/hr, the difference of sound pressure level between 2nd and 4th gear engaged is 5.4dB. The study is continued by using a modified muffler which contains sound absorptive materials. The absorptive materials chosen are glass wool, cotton and Styrofoam and they are taking turn to be placed into the modified muffler to reduce the sound pressure level. Then the experiment is repeated. By applying 100g absorptive materials in the modified muffler, the reduction of sound pressure level are recorded as 12.6% (glass wool), 7.5% (cotton) and 4.4% (Styrofoam) compared with original installed muffler while 2nd gear engaged. Styrofoam is observed does not perform significantly in absorbing sound or noise in this study. Glass wool demonstrates relatively better sound energy absorption compared with cotton. In general, soft and porous materials are considered good performance in sound absorption. Denser materials are better at soundproofing or sound blocking. Therefore, glass wool with relatively higher density among the investigated absorptive materials in this study has the greatest sound absorption performance.
  • Publication
    Dielectric spectroscopy technique for carbohydrate characterization of fragrant rice, brown rice and white rice
    ( 2017-11-20)
    Cheng Ee Meng
    ;
    Kok Yeow You
    ;
    Lee KimYee
    ;
    Abbas Z.
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Khor Shing Fhan
    ;
    Zulkarnay Zakaria
    ;
    Lee Y.S.
    This study was conducted to investigate the feasibility of microwave dielectric spectroscopic technique in characterizing commercial rice due to different level of moisture content. There are some unethical rice industry runner mixes good qualities of rice which can be sold at high price with low cost and quality of rice to maximize profit. It causes fraudulency in business and great lost in term of money to nation who take rice as staple food. It happens frequently in Asian country which is active in agricultural activities. This technique is implemented using Keysight E8362B network analyzer in conjunction with an Keysight 85070E dielectric probe ranging from 200 MHz to 10 GHz. The samples of study are commercially available at market, namely fragrant rice, white rice, and brown rice, respectively. These are the popular and favorite rice for Malaysian due its delicacy and affordable price. Nutrient level for fragrant rice, white rice, and brown rice in terms of protein, moisture, carbohydrate and fat are different and unique. It leads to various electromagnetic responses toward frequency. Dielectric and reflection measurement were conducted to characterize these rice. The presence of polar and non-polar molecules in nutrient of rice causes variation of dielectric and reflection behavior over the operating frequency range.
  • Publication
    MICROWAVE ABSORPTION ANALYSIS ON HEATED EDIBLE SPIRULINA WITH VARIOUS TEMPERATURES
    ( 2023-05-01)
    Cheng Ee Meng
    ;
    Tan Wei Hong
    ;
    Tan Wee Choon
    ;
    Lim Eng Aik
    This paper discusses the microwave absorption analysis of edible Spirulina by using WR62 and WR90 rectangular waveguides in conjunction with Agilent P-series Vector Network Analyzer (PNA). Heat might lead to the degradation of spirulina. This phenomenon involves the chemical and physical reaction that is associated with the variation of dielectric properties. These properties determine the propagation mechanism of microwaves within the sample or material. Hence, an assessment method to detect a nutrient change in spirulina due to heat is necessary. In this context, a microwave absorption measurement system was developed to study the reflection coefficient, transmission coefficient, and absorption coefficient of Spirulina tablets over temperature. The transmission/Reflection line method is well-known because it is non-destructive and rapid in analyzing chemical and physical properties. In this work, Spirulina tablet is used since it is a popular food supplement that is believed to be able to treat diseases is and good for health. The reflection, transmission, and absorption measurements were conducted on Spirulina from 12.4GHz to 18GHz.
  • Publication
    Effects of Moisture Content and Temperature on Microwave Measurement of Lightweight Foamed Concrete
    ( 2024)
    Kim-Yee Lee
    ;
    Yeong-Nan Phua
    ;
    Siong-Kang Lim
    ;
    Kok-Yeow You
    ;
    Cheng Ee Meng
    Abstract The effects moisture content and temperature are important in microwave measurements and building material engineering. In this article, the relationship between the effects of moisture content/temperature and microwave measurements of lightweight foamed concrete is investigated. A frequency sweep measurement from 150 kHz to 8 GHz was performed on 10-cm cube samples with varying moisture content (0–20 %) and temperature (20°C–40°C). The microwave S-parameters were measured using an R&S ZVB8 Vector Network Analyzer with an N-type open-ended coaxial sensor and were used to calculate the dielectric constant. Models were developed to describe the relationship between moisture content, temperature, and dielectric characteristics of the concrete. Validation showed that the error was below 5 % for dielectric constant and below 8 % for loss factor at 5-GHz frequency. These findings have implications for the telecommunications industry and on-site moisture content measurements, with potential applications in building material engineering.
  • Publication
    Dynamic mechanical analysis of graphene nanoplatelets/glass reinforced epoxy composite
    ( 2021-10-25)
    Ahmad M.A.A.
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Mohd Shukry Abdul Majid
    ;
    Cheng Ee Meng
    ;
    Sulaiman M.H.
    This paper presents a study on dynamic mechanical analysis (DMA) of graphene nanoplatelets (GNPs)/glass reinforced epoxy composite. The composite was fabricated by a hand lay-up technique followed by vacuum bagging technique. GNPs weight fraction was 0.5 and 1.5 wt.% for a fixed glass fibre fraction. The test was carried out in terms of storage modulus (E’), loss modulus (E”), and tan δ. The result indicates that 1.5 wt.% GNPs/glass reinforced epoxy composite obtain the maximum value of the dynamic mechanical properties due to the incorporation of GNPs nanofiller. The improved dynamic mechanical properties were related to better interfacial interaction of the nanofiller with the epoxy matrix. The glass transition temperature (Tg) value for 0.5 and 1.5 wt.% GNPs/glass were 62.84 and 66.01 °C, respectively.
  • Publication
    Numerical analysis on the effect of diluted hydrogen fuel by a fixed amount of supplied hydrogen using a quasi-three-dimensional solid oxide fuel cell model
    (Asian Research Publishing Network (ARPN), 2023)
    Tan Wee Choon
    ;
    Lim Eng Aik
    ;
    Cheng Ee Meng
    ;
    Tan Wei Hong
    ;
    Hamimah Abd Rahman
    Solid oxide fuel cell (SOFC) has excellent fuel flexibility for various fuels. Despite some drawbacks like storage and transportation, hydrogen stands up as the best fuel for SOFC. Hydrogen fuel is diluted non-reactive gas species before it is supplied to the SOFC. In this study, a quasi-three-dimensional SOFC model with real microstructure is used to analyse the effect of the diluted fuel mixture. The hydrogen fuel is diluted with nitrogen and a small amount of steam. The mole amount of hydrogen within fuel mixtures is kept constant. On the other hand, the air that is supplied to the air channel of the SOFC remains unchanged. It is found that the cell that is supplied with the highest concentration of hydrogen has the highest performance due to its high partial pressure of hydrogen within the fuel mixture. Such a high partial pressure promotes a low anode concentration loss. Also, the cell that is supplied with a low hydrogen concentration is unable to benefit from its high average cell temperature as its performance is drained by the low partial pressure of hydrogen within the fuel mixture.
  • Publication
    Microwave reflectometry circuits integration with coaxial probe for initial breast tumor detection
    (Penerbit UTM Press, 2025-01)
    Kok Yeow You
    ;
    Nadera Najib Al-Areqi
    ;
    Wei Jer Lim
    ;
    Kim Yee Lee
    ;
    Cheng Ee Meng
    ;
    Cheng Seong Khe
    A six-port reflectometry (SPR) system was developed to predict the dielectric properties of both tumor and normal breast tissue, intended for medical diagnostic applications. Ensuring precise measurements, the SPR underwent calibration using a well-established four-step procedure, which will be briefly outlined. Afterward, the investigated coaxial probe was connected to the SPR through the calibrated measurement port. Subsequently, the exposed end of the probe aperture was immersed into synthetic samples representing both healthy and cancerous breast tissue to assess the dielectric constant, εrʹ and loss factor, εrʺ across frequencies ranging from 1.5 GHz to 3.3 GHz. The dielectric constant, εrʹ and loss factor, εrʺ were derived from the measured reflection coefficient using a closed-form equation associated with the coaxial probe. An examination was undertaken to compare the performance of a commercially available vector network analyzer (VNA) outfitted with a Keysight 85070E dielectric probe against an SPR-probe system. The comparison was based on analyzing the reflection coefficient magnitude, phase shift, dielectric constant, and loss factor of synthetic breast tissue samples. The study revealed maximum absolute errors of 0.01, 1.07°, 1.12, and 0.75 for the measured reflection coefficient magnitude, phase shift, dielectric constant, and loss factor, respectively. The calibrated reflection coefficient and predicted relative permittivity, εr can be effectively utilized to distinguish between normal (εrʹ < 50) and tumor (εrʹ > 50) breast tissue.
  • Publication
    Radiation and scattering by a multilayer uniaxial bianisotropic circular cylindrical scatterer
    (Taylor and Francis Ltd., 2025)
    Tze Wei Ng
    ;
    Amizadillah Md Norimi
    ;
    Sim Bio Lim
    ;
    Tiong Lim Ng
    ;
    Mohd Amiruddin Abd Rahman
    ;
    Mohamad Faiz Zainuddin
    ;
    Fahmiruddin Esa
    ;
    Kok Yeow You
    ;
    Kim Yee Lee
    ;
    Cheng Ee Meng
    ;
    Mohamad Ashry Jusoh
    ;
    Zulkifly Abbas
    The eigenfunction solution of electromagnetic radiation and scattering from a multilayer uniaxial bianisotropic circular cylindrical scatterer is presented. The expressions for the electric and magnetic field equations are decomposed into transverse and longitudinal components. The boundary conditions are enforced by matching the transverse and axially directed fields at the interfaces between regions with different constitutive parameters. Matrices are constructed from the linear algebraic equations to solve the unknown series coefficients. On the one hand, numerical results are presented for the near zone fields and radar cross section in the two dimensional case. On the other hand, numerical solutions are presented for the radiation pattern when a dipole is present in the vicinity of the cylindrical scatterer in the three dimensional case. Results obtained using the eigenfunction series for the multilayer uniaxial bianisotropic circular cylindrical scatterer are in excellent agreement with results in existing literature and solutions computed using other formulations.
  • Publication
    Synthesizing and Optimization the Hydroxyapatite Based on Corbiculacea Seashells
    ( 2021-01-01)
    Mohd Riza Mohd Roslan
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Nur Farahiyah Mohammad
    ;
    Cheng Ee Meng
    ;
    Nasrul Amri Mohd Amin
    ;
    Abdul Khalid M.F.
    ;
    Mohd Zakimi Zakaria
    ;
    Muhammad Mokhzaini Azizan
    ;
    Muzammil Jusoh
    Hydroxyapatite (HA) is one of the main components in bone which functions to enhance its cell regeneration. Synthetically produced HA, based on seashell resources has higher biocompatibility, and in high demand especially in bone tissue engineering. However, the secondary phase of HA production are calcium oxide and carbonate, which impedes its performance. HA is synthesized via wet chemical precipitation and optimization were done to obtain nearly pure HA by manipulating the pH value and sintering temperature. It is expected that the combination of these parameters will optimize the amount of secondary phase hence attained nearly stoichiometric or pure HA. HA powders were analyzed through Fourier Transform Infrared Spectroscopy (FTIR) and Energy Dispersive X-ray Spectrometry (EDX).
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