Cheng Ee Meng, Dr.
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/32921
2024-03-29T13:50:41ZElectromagnetic Properties Performance of MWCNTs/Polyester Composites in X-band
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/69199
Electromagnetic Properties Performance of MWCNTs/Polyester Composites in X-band
Y. S., Lee; F. H., Wee; K. Y., You; C. Y., Lee; Y. Y., Lee; L., Zahid; Nur Hidayah, Ramli; M. S., Shakhirul; Nurulbariah, Idris; E. M., Cheng
In this paper presents nano-composites based on polyester (PE) matrix with multi-walled carbon nanotubes (MWCNTs) as fillers have been developed for microwave absorbing materials. The MWCNTs/PE composite samples were fabricated with different weight ratio of MWCNTs (3 wt%, 5 wt%, and 10 wt%). The electromagnetic properties of different MWCNTs/PE composite have been determined by using rectangular waveguide technique and Agilent material measurement software. Moreover, the reflection loss (microwave absorption) of MWCNTs/PE composite have been calculated based on the basis of transmission line theory. The performance of electromagnetic properties and microwave absorption of MWCNTs/PE composite were analyzed in X-band frequency. The dielectric loss properties of the composite are increse with increasing in MWCNTs weight ratio. The microwave absorption results show that such 3 wt% MWCNTs/PE composites sample with 4 mm thickness has achieved less than -10 dB values (< 90 % microwave absorption) of reflection loss.
Link to publisher's homepage at https://www.matec-conferences.org/
2018-01-01T00:00:00ZThe Characterization of Bario Rice Starch-nanoHA Scaffolds using SEM and Dielectric Measurement
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/69020
The Characterization of Bario Rice Starch-nanoHA Scaffolds using SEM and Dielectric Measurement
M.Riza, Roslan; Nashrul Fazli, Mohd Nasir; M.F., Abdul Khalid; Nasrul Amri, Mohd Amin; N. Mohammad; Beh Chong, You; Cheng Ee, Meng; Mohd Shukry, Abdul Majid
Bone tissue scaffold had been ventured for over the decades as a solution for bone failure and trauma. Starch is the most common natural polymer that has been used as a biomaterials and a good candidate for scaffold fabrication as there are many resources of starch in Malaysia. Native starches may contribute differently in their structure in terms of the amylose content, interactions between granules, swelling ability and solubility in which those differences can be mainly due to the botanical origin. In Malaysia, there are various resources of rice starches. Here, the Bario rice starch from Sarawak was used to fabricate the scaffold via solvent casting and salt leaching technique. Bario rice is usually collected from various sources and variety which may contribute to different physical affect in comparison of using other type of rice. From the study, the morphologies and microstructures of the scaffold were evaluated using Scanning Electron Microscopic (SEM) and this showed no trend of pore size increment when starch percentage varied. Then, the dielectric properties were obtained via the values of dielectric constant and dielectric loss which are another type of indirect measurement to study the porosity of the scaffolds. The porosity has the value of the dielectric constant and the loss air matrix whereby this air matrix is represented by the pore in the scaffold. Here, the results were consistent with the observation made through SEM. Thus, the relationship between the porosity and the dielectric properties of the Bario Rice Starch-nHA tissue scaffolds had been established and there were no particular pattern could be concluded by using Bario rice for this scaffold.
Link to publisher's homepage at https://iopscience.iop.org/
2019-01-01T00:00:00ZHardened Glass Particle and Carbon Black using Resin for Potential Electromagnetic Shielding in Biomedical Electronic Equipments
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/69013
Hardened Glass Particle and Carbon Black using Resin for Potential Electromagnetic Shielding in Biomedical Electronic Equipments
Cheng Ee, Meng; Mohd Shukry, Abdul Majid; Shahriman, Abu Bakar; Nashrul Fazli, Mohd Nasir; Khor Shing, Fhan; You Kok, Yeow; Lee Kim, Yee; Mohd Ridzuan, Mohd Jamir
This study aims to investigate the electromagnetic properties of a composite of hardened glass particle and carbon using resin in determining the absorbability of the composite for electromagnetic interference (EMI). The electromagnetic absorption measurement was conducted using T-R method (transmission-reflection) by measuring the dielectric constant, loss factor, real and imaginary part of permeability, reflection coefficient and transmission coefficient. The measurement is taken for X band frequency and Ku band frequency within the frequency range from 8.2GHz to 12.4GHz and 12.4GHz to 18GHz, respectively. Dielectric constant of sample decrease when frequency increases. The high dielectric constant of material implies that the material has high absorbability of field energy, resulting in high attenuation of the applied field.
Link to publisher's homepage at https://iopscience.iop.org/
2019-01-01T00:00:00ZThe Optimization of the Hydroxyapatite (HA) Material Characteristics Produced from Corbiculacea (Etok) Shells
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/69011
The Optimization of the Hydroxyapatite (HA) Material Characteristics Produced from Corbiculacea (Etok) Shells
Mohd Riza, Roslan; Nashrul Fazli, Mohd Nasir; Mohd Farid, Abdul Khalid; Nur Farahiyah, Mohammad; Cheng Ee, Meng; Nor Nabielah Nazihah, Hashim; Beh Chong, You; Mohd Shukry, Abd. Majid; Nasrul Amri, Mohd Amin
Hydroxyapatite commonly used in medical field for tissue disease, bone disease, drug delivery and also for non-medical field purpose such as wastewater treatment. Due to excellent biocompatibility and bioactive properties, hydroxyapatite (HA) which is a group of calcium phosphate (CaP) and similar to the natural bone composition has been broadly ventured in medical area. Synthesising the HA was done via precipitation method by implementing the Corbiculacea (Etok) shells as the resource of calcium precursors. Calcination of Corbiculacea (Etok) shells took place to convert calcium carbonate (𝐶𝑎𝐶𝑂3) to
calcium oxide(𝐶𝑎𝑂). CaO were then reacted with water to form calcium hydroxide (𝐶𝑎(𝑂𝐻)2) and later, reacted with phosphoric acid(𝐻3𝑃𝑂4). This experiment manipulated the CaP ratio to study the properties HA formed. CaP ratios used are 1.50, 1.67 and 2.00. The characterization were performed using Energy Dispersive X-Ray Spectroscopy (EDS), Scanning Electron Microscopy (SEM) and Fourier Transformation Infrared (FTIR).
Link to publisher's homepage at https://iopscience.iop.org/
2019-01-01T00:00:00Z