Mohd Ridzuan Mohd Jamir
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Preferred name
Mohd Ridzuan Mohd Jamir
Official Name
Mohd Ridzuan , Mohd Jamir
Alternative Name
Ridzuan Mohd Jamir, Mohd
M Ridzuan, M. J.
Ridzuan, M. J.M.
Mohd Jamir, Mohd Ridzuan
Jamir, Mohd Ridzuan Mohd
Main Affiliation
Scopus Author ID
36069815000
Researcher ID
H-9343-2012

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  • Publication
    Regression analysis of the dielectric and morphological properties for porous Nanohydroxyapatite/Starch composites: a correlative study
    ( 2022)
    Chong You Beh
    ;
    Cheng Ee Meng
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Shukry Abdul Majid
    ;
    Khor Shing Fhan
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Emma Ziezie Mohd Tarmizi
    ;
    Kim Yee Lee
    This paper aims to investigate the dielectric properties, i.e., dielectric constant (ε′), dielectric loss factor (ε″), dielectric tangent loss (tan δ), electrical conductivity (σ), and penetration depth (Dp), of the porous nanohydroxyapatite/starch composites in the function of starch proportion, pore size, and porosity over a broad band frequency range of 5 MHz–12 GHz. The porous nanohydroxyapatite/starch composites were fabricated using different starch proportions ranging from 30 to 90 wt%. The results reveal that the dielectric properties and the microstructural features of the porous nanohydroxyapatite/starch composites can be enhanced by the increment in the starch proportion. Nevertheless, the composite with 80 wt% of starch proportion exhibit low dielectric properties (ε′, ε″, tan δ, and σ) and a high penetration depth because of its highly interconnected porous microstructures. The dielectric properties of the porous nanohydroxyapatite/starch composites are highly dependent on starch proportion, average pore size, and porosity. The regression models are developed to express the dielectric properties of the porous nanohydroxyapatite/starch composites (R2 > 0.96) in the function of starch proportion, pore size, and porosity from 1 to 11 GHz. This dielectric study can facilitate the assessment of bone scaffold design in bone tissue engineering applications.
  • Publication
    The Effect of the Amylose/Amylopectin Contents of Starch on Porosity and Dielectric Properties of the Porous Hydroxyapatite/Starch Composites
    ( 2020-07-09)
    Chong You B.
    ;
    Cheng Ee Meng
    ;
    Abu Bakar S.
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Eng Swee Kheng
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Khor Shing Fhan
    This study aims to determine the effect of the amylose/amylopectin contents of starch on the porosity and dielectric properties of porous hydroxyapatite/starch composites. The porous hydroxyapatite/starch composites were prepared by utilizing the starches (rice, corn and potato starch) via gelatinization and retrogradation process. The complex permittivity of the porous hydroxyapatite/starch composites were evaluated in the frequency range of 12.4-18.0 GHz. The porous composites were exhibited the higher average porosity by using the starch with higher amylopectin content. The highly porous hydroxyapatite/starch composites with higher amylopectin content show the significant fluctuation peaks (at 13.8 and 16.6 GHz) and the higher imaginary part of the complex permittivity (ϵ′′) at higher frequency in the dielectric spectrum, respectively. The real (ϵ′) and imaginary part (ϵ′′) of the complex permittivity of the porous composites could be enhanced by increasing the average porosity and the amylopectin contents.
  • Publication
    Microwave dielectric analysis on adhesive disbond in acrylic glass (Poly (Methyl Methacrylate)) at KU-band
    ( 2020-10-01)
    Cheng Ee Meng
    ;
    Mohd A.R.
    ;
    Shahriman Abu Bakar
    ;
    Zuradzman Mohamad Razlan
    ;
    You K.Y.
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Shukry Abdul Majid
    ;
    Khairul S.B.
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Beh C.Y.
    ;
    Khor Shing Fhan
    A microwave dielectric spectroscopy for detecting adhesive disbonds between acrylic glass (aka Poly (methyl methacrylate)) was discussed. The adhesive bond was developed using epoxy resin and acrylate. The level of joint disbond can be quantified using Young Modulus. In this work, the strength of bond is affected by radius of air void within adhesive bond. A high-frequency electromagnetic wave propagated through two joint acrylic glass with acrylate and epoxy adhesive using waveguide adaptor WR90 in conjunction with professional network analyser. This electromagnetic wave is reflected and transmitted at the bond interface due to mismatch impedance at adhesive bond. The output is a dielectric properties that characterizes the bond interface. The increment of Young Modulus leads to increment of dielectric constant and loss factor for epoxy resin and acrylates, respectively.
  • Publication
    Regression analysis of the dielectric and morphological properties for Porous Nanohydroxyapatite/Starch composites: a correlative study
    ( 2022)
    Chong You Beh
    ;
    Cheng Ee Meng
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Shukry Abdul Majid
    ;
    Khor Shing Fhan
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Emma Ziezie Mohd Tarmizi
    ;
    Kim Yee Lee
    This paper aims to investigate the dielectric properties, i.e., dielectric constant (ε′), dielectric loss factor (ε″), dielectric tangent loss (tan δ), electrical conductivity (σ), and penetration depth (Dp), of the porous nanohydroxyapatite/starch composites in the function of starch proportion, pore size, and porosity over a broad band frequency range of 5 MHz–12 GHz. The porous nanohydroxyapatite/starch composites were fabricated using different starch proportions ranging from 30 to 90 wt%. The results reveal that the dielectric properties and the microstructural features of the porous nanohydroxyapatite/starch composites can be enhanced by the increment in the starch proportion. Nevertheless, the composite with 80 wt% of starch proportion exhibit low dielectric properties (ε′, ε″, tan δ, and σ) and a high penetration depth because of its highly interconnected porous microstructures. The dielectric properties of the porous nanohydroxyapatite/starch composites are highly dependent on starch proportion, average pore size, and porosity. The regression models are developed to express the dielectric properties of the porous nanohydroxyapatite/starch composites (R2 > 0.96) in the function of starch proportion, pore size, and porosity from 1 to 11 GHz. This dielectric study can facilitate the assessment of bone scaffold design in bone tissue engineering applications.
  • Publication
    Dielectric and Colorimetric Analysis on Thermal Degradation of Cooking Oil
    ( 2021-01-01)
    Cheng Ee Meng
    ;
    Zakaria A.
    ;
    Bakar S.A.
    ;
    Kheng E.S.
    ;
    Ahmad Nasrul Norali
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Fhan K.S.
    ;
    Mohd Shukry Abdul Majid
    ;
    Yee L.K.
    ;
    Mohd Ridzuan Mohd Jamir
    In this work, dielectric and colorimetric properties of cooking oil is investi-gated for quality of cooking oil. An interdigitated electrode sensor (IDE), RGB colour detector and LCR (inductance–capacitance–resistance) meter were used to study colorimetric properties. The measured data was analyzed using principal component analysis, differential evolution feature extraction and major voting fusion. In dielectric measurement, there are different re-markable signal pattern which indicates the resistance change for used and fresh cooking oil. In addition, ten frequencies which can provide distinctive pattern were selected using differential evolution feature extraction. Nine types of cooking oil are then classified into used and fresh oil class. Major voting fusion exhibit 83% accuracy in classifying the oil. In the meantime, it can distinguish the used and fresh vegetable oils with approximately 100% accuracy. On the other hand, the results of colorimetric measurement indi-cate that this method can determine quality of frying oil accurately based on its type of oil, oil freshness, and duration of oil to fry.
  • Publication
    Biodegradation of PLA-Pennisetum purpureum based biocomposite scaffold
    ( 2017-10-29)
    Revati R.
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Normahira Mamat @ Mohamad Nor
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Cheng Ee Meng
    The in vitro degradation and mechanical properties of a 3D porous Pennisetum purpureum (PP)/polylactic acid (PLA) - based scaffold was investigated. In this study, composite scaffolds with PP to PLA ratio of 0%, 10%, 20%, and 30% were immersed in PBS solution at 37 °C for 40 days. Interestingly, the degradation rate was reduced for the PLA/PP20 scaffold, though insignificantly, this could be attributed to the improved mechanical properties and stronger fibre-matrix interface. The FESEM results indicated that a sound fibre-matrix interface was formed in the PLA/PP20 scaffold, which reflected the addition of P. purpureum into PLA decreasing the degradation rate compared to in pure PLA scaffolds. The results suggest that the P. purpureum/PLA scaffold degradation rate can be altered and controlled to meet the requirement imposed by a given tissue engineering application.
  • Publication
    Microwave dielectric analysis on porous hydroxyapatite/starch composites with various ratio of hydroxyapatite to starch
    ( 2020-07-09)
    You B.C.
    ;
    Cheng Ee Meng
    ;
    Shahriman Abu Bakar
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Eng Swee Kheng
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Khor Shing Fhan
    This study aims to investigate the dielectric response of the porous hydroxyapatite/starch composites by varying the starch proportion in determining the feasibility of the microwave sample characterization technique in bone tissue engineering. The porous hydroxyapatite/starch composites were fabricated by using natural starch (gelatinization and retrogradation) through the solvent casting and particulate leaching technique. The dielectric constant (ϵ′) and loss factor (ϵ″) of the complex permittivity of the porous hydroxyapatite/starch composites were measured in the Ku band frequency of 12.4-18.0 GHz. ϵ′ and ϵ″ of the porous composites increase with frequency. The highly porous composite that due to higher starch proportion exhibit higher ϵ′ and ϵ″, resulting in the significant dielectric responses.
  • Publication
    Lumped-element circuit modeling for composite scaffold with nano-hydroxyapatite and wangi rice starch
    ( 2023)
    Xiao Jian Tan
    ;
    Cheng Ee Meng
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Khor Shing Fhan
    ;
    Kim Yee Lee
    ;
    Kok Yeow You
    ;
    Che Wan Sharifah Robiah Mohamad
    Mechanistic studies of the interaction of electromagnetic (EM) fields with biomaterials has motivated a growing need for accurate models to describe the EM behavior of biomaterials exposed to these fields. In this paper, biodegradable bone scaffolds were fabricated using Wangi rice starch and nano-hydroxyapatite (nHA). The effects of porosity and composition on the fabricated scaffold were discussed via electrical impedance spectroscopy analysis. The fabricated scaffold was subjected to an electromagnetic field within the X-band and Ku-band (microwave spectrum) during impedance/dielectric measurement. The impedance spectra were analyzed with lumped-element models. The impedance spectra of the scaffold can be embodied in equivalent circuit models composed of passive components of the circuit, i.e., resistors, inductors and capacitors. It represents the morphological, structural and chemical characteristics of the bone scaffold. The developed models describe the impedance characteristics of plant tissue. In this study, it was found that the ε′ and ε″ of scaffold composites exhibited up and down trends over frequencies for both X-band and Ku-band. The circuit models presented the lowest mean percentage errors of Z′ and Z″, i.e., 3.60% and 13.80%, respectively.
  • Publication
    Lumped-element circuit modeling for composite scaffold with Nano-Hydroxyapatite and wangi rice starch
    ( 2023)
    Xiao Jian Tan
    ;
    Cheng Ee Meng
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Shukry Abdul Majid
    ;
    Mohd Ridzuan Mohd Jamir
    ;
    Khor Shing Fhan
    ;
    Kim Yee Lee
    ;
    Kok Yeow You
    ;
    Che Wan Sharifah Robiah Mohamad
    Mechanistic studies of the interaction of electromagnetic (EM) fields with biomaterials has motivated a growing need for accurate models to describe the EM behavior of biomaterials exposed to these fields. In this paper, biodegradable bone scaffolds were fabricated using Wangi rice starch and nano-hydroxyapatite (nHA). The effects of porosity and composition on the fabricated scaffold were discussed via electrical impedance spectroscopy analysis. The fabricated scaffold was subjected to an electromagnetic field within the X-band and Ku-band (microwave spectrum) during impedance/dielectric measurement. The impedance spectra were analyzed with lumped-element models. The impedance spectra of the scaffold can be embodied in equivalent circuit models composed of passive components of the circuit, i.e., resistors, inductors and capacitors. It represents the morphological, structural and chemical characteristics of the bone scaffold. The developed models describe the impedance characteristics of plant tissue. In this study, it was found that the ε′ and ε″ of scaffold composites exhibited up and down trends over frequencies for both X-band and Ku-band. The circuit models presented the lowest mean percentage errors of Z′ and Z″, i.e., 3.60% and 13.80%, respectively.
  • Publication
    Dielectric Properties of Hydrothermally Modified Potato, Corn, and Rice Starch
    ( 2022-06-01)
    Beh C.Y.
    ;
    Cheng Ee Meng
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohd Tarmizi E.Z.
    ;
    Khor Shing Fhan
    ;
    Mohd Shukry Abdul Majid
    ;
    Lee K.Y.
    ;
    Mohd Ridzuan Mohd Jamir
    The effect of starch granule sizes, shapes, composition, and frequency on the dielectric properties (dielectric constant, loss factor, and conductivity) of native and hydrothermally modified starches (potato, corn, and rice starch) are investigated in this work. Dielectric properties are determined from 5 Hz to 5 GHz. The modified starches exhibit lower dielectric properties than the native starches from 5 Hz to 5 GHz due to the disruption of the native polysaccharide’s molecular arrangement. The modified potato starch shows the highest loss factor (208.12 at 50 Hz and 19.95 at 500 Hz) and stable conductivity (~5.33 × 10−7 S/m at 50 Hz and 500 Hz) due to the larger continuous network structure after hydrothermal modification. The rice starch shows the largest difference in dielectric constant (47.30%) and loss factor (71.42%) between the modified form and native form in the frequency range of 5 MHz–5 GHz. This is due to the restriction of dipole motions in the closely packed structure after hydrothermal modification. The findings indicate that the quality of starch modification can be characterized by dielectric properties for assisting starch-based plastic production’s design.
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