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Papers by nor zakiah yahaya

Research paper thumbnail of Determination of Anechoic Chamber Set-Up Using Simulation Approach: A Review

Lecture notes in electrical engineering, 2024

Research paper thumbnail of A Review of Slotted Hollow Pyramidal Absorbers for Microwave Frequency Range

Lecture notes in electrical engineering, 2024

Research paper thumbnail of Theory, Modeling, Measurement, and Testing of Electromagnetic Absorbers: A Review

physica status solidi (a)

In the era of the fifth generation (5G) and the Internet of Things (IoT), electromagnetic interfe... more In the era of the fifth generation (5G) and the Internet of Things (IoT), electromagnetic interference (EMI) poses a significant challenge. The rapid growth of wireless communication applications leads to increased electromagnetic (EM) pollution, which can have adverse health effects. To address this issue, electromagnetic absorbers (EMAs) play a critical role in eliminating EMI and reducing EM pollution between electronic devices. The focus is now on developing diverse microwave absorbing materials (MAMs) with different structures to cover a wide range of frequencies while remaining cost‐effective and effective at high angles of incidence radiation. This article comprehensively reviews EMAs, highlighting their design parameters and importance in achieving high‐efficiency absorption. The review covers absorber theory, structure, materials for various frequency ranges, and the mechanisms responsible for dissipating electromagnetic waves (EMWs). Analytical and numerical methods for mo...

Research paper thumbnail of From Rice Husk to Transparent Radiation Protection Material

Jurnal Intelek, Sep 14, 2015

Research paper thumbnail of Effects of Grain Sizes on Rice Husk Ash Composite as Microwave Absorber

Journal of physics, Aug 1, 2018

Research paper thumbnail of Effect of Bi2O3 particle sizes and addition of starch into Bi2O3–PVA composites for X-ray shielding

Applied Physics A, Aug 12, 2016

Research paper thumbnail of Radiotherapy dose verification on a customised head and neck perspex phantom

Journal of physics, May 1, 2017

Research paper thumbnail of Gafchromic XRQA-2 film for Strontium-90/Yttrium-90 (Sr-90/Y-90) Detection

Journal of Physics: Conference Series

Research paper thumbnail of Reflection technique for estimation of moisture hevea rubber latex content using rectangular patch antenna

In this paper, the designed microstrip patch antenna is employed to study reflection technique an... more In this paper, the designed microstrip patch antenna is employed to study reflection technique and predict moisture content of Hevea Rubber Latex. The rectangular patch sensor was designed to operate at microwave frequency range from 0.1 to 5 GHz on a RT/Duroid substrate with 6.15 ±0.015 permittivity and 1.27 mm thickness. The width and length of the rectangular patch antenna was 18 mm and 38 mm, respectively. The phase shift reflection coefficient, ΔӨ of rubber latex are obtained with moisture content at all selected frequencies. Estimation equations phase shift of reflection coefficient as a function of moisture content were developed at several selected frequencies. These equations were used to predict the amount of moisture content on Hevea latex based on the measured phase of reflection coefficient, ϕ using Agilent Professional Network Analyzer N5230A (PNA). The actual values of moisture content were obtained using standard oven drying method. The lowest mean relative error bet...

Research paper thumbnail of 5G Millimeter Wave Wearable Antenna: State-Of-the-Art and Current Challenges

2021 IEEE Asia-Pacific Conference on Applied Electromagnetics (APACE)

Research paper thumbnail of Trace of heavy metals in maternal and umbilical cord blood samples in association with birth outcomes in Baghdad, Iraq

EPJ Web of Conferences, 2017

Research paper thumbnail of Combined Role of Material Composition and Thickness of Activated Carbon/Natural Rubber Composite Microwave Absorbers in the Absorption of Within the 1–18 GHz Frequency Range: A Review

Lecture Notes in Electrical Engineering, 2022

Research paper thumbnail of Ultrathin Metamaterial Microwave Absorber Using Coconut Coir Fibre over X-Band Frequency Range

2019 International Conference on Communications, Signal Processing, and their Applications (ICCSPA), 2019

This paper presents the new design of simple one layer ultrathin metamaterial microwave absorber ... more This paper presents the new design of simple one layer ultrathin metamaterial microwave absorber using coconut coir fibre as the substrate. The metamaterial microwave absorber is composed of a periodic array of square loops and patches with circle cut out printed on a dielectric material which is coconut coir fibre backed by PEC. CST Microwave Studio software is used for the design and simulation over frequency range of X-Band and Ku-Band (8.2–18 GHz). From the simulation result, 90% absorption was achieved in the frequency range of 8.94 – 10.0 GHz (X-Band) with highest absorption of 99.7% at 9.37 GHz. Furthermore, the metamaterial microwave absorber has a total thickness of 1.6 mm which is only approximately 0.04λ at lowest frequency. The result shows that coconut coir fibre from the agricultural waste has a great potential to be developed further in electromagnetic wave applications particularly microwave absorber.

Research paper thumbnail of Effects of Grain Sizes on Rice Husk Ash Composite as Microwave Absorber

Journal of Physics: Conference Series, 2018

Research paper thumbnail of From Rice Husk to Transparent Radiation Protection Material

High amount of silica (SiO2) content, 99.36% was successfully prepared from Rice Husk Ash (RHA)th... more High amount of silica (SiO2) content, 99.36% was successfully prepared from Rice Husk Ash (RHA)through the burning of rice husk. Eventually, quaternary glasses were fabricated using melt quenchingtechnique based on chemical compound composition xBi2O3 - (1-x)ZnO - 0.2B2O3 - 0.3(SiO2)RHA. Thefinal thickness of glass samples prepared was within ~3.41mm. As the mole percentages of Bi2O3increased, the glass density and molar volume was also increased from 4.45 gcm-1 to 6.60 gcm-1. Theincrement is due to larger atomic number of Bi3+ compared to the Si2+, B3+ and Zn in the glass samples.However, the oxygen packing density decreased as mole percentages of Bi2O3 were increased from 240.44g-atom/l to 161.24 g-atom/l. The decreasing in oxygen packing density was due to the high non-bridgingoxygen in the glass samples. The radiation attenuation parameterization was measured using 241Am assource of gamma ray interactions at energy 59.54 keV. The mass attenuation coefficient increased from0.53cm...

Research paper thumbnail of The dose enhancement of MAGAT gel dosimeter doped with zinc oxide at 6 MV photon beam

Radiation Physics and Chemistry, 2020

Research paper thumbnail of Finite Element Analysis of Simple Rectangular Microstrip Sensor for Determination Moisture Content of Hevea Rubber Latex

Journal of Physics: Conference Series, 2018

The Finite Element Method, FEM has been successfully used to model a simple rectangular microstri... more The Finite Element Method, FEM has been successfully used to model a simple rectangular microstrip sensor to determine the moisture content of Hevea rubber latex. The FEM simulation of sensor and samples was implemented by using COMSOL Multiphysics software. The simulation includes the calculation of magnitude and phase of reflection coefficient and was compared to analytical method. The results show a good agreement in finding the magnitude and phase of reflection coefficient when compared with analytical results. Field distributions of both the unloaded sensor as well as the sensor loaded with different percentages of moisture content were visualized using FEM in conjunction with COMSOL software. The higher the amount of moisture content in the sample the more the electric loops were observed.

Research paper thumbnail of Radiotherapy dose verification on a customised head and neck perspex phantom

Journal of Physics: Conference Series, 2017

Research paper thumbnail of Optimisation of the MAGAT gel dosimeter compositions

Internatuinal Journal of Radiation Research, 2016

Research paper thumbnail of Choice of Evaluation Imaging Technique for MAGAT Polymer Gel Dosimeter

Asian Journal of Applied Sciences

_________________________________________________________________________________ ABSTRACT— The d... more _________________________________________________________________________________ ABSTRACT— The development of the polymer gel dosimeter evaluation focused mainly on magnetic resonance imaging (MRI) techniques. A new alternative imaging technique which is x-ray CT imaging has emerged from a current research. The study focused on the dose response, the dose sensitivity and the accuracy of the MAGAT gel dosimeter using two different imaging modalities. The MAGAT gel dosimeter was irradiated at 1, 5 and 10 Gy 24-h post-manufacturing. The imaging of MAGAT gel dosimeter by MRI and x-ray CT were done a day post-irradiation using an optimized protocol. The dose sensitivity of the gel obtained by the MRI technique was 0.7157 s-1 Gy-1 , whereas the dose sensitivity obtained by the x-ray CT technique was 0.6177 HGy-1. Keywords— MAGAT gel dosimeter, dose response, MRI imaging, x-ray CT

Research paper thumbnail of Determination of Anechoic Chamber Set-Up Using Simulation Approach: A Review

Lecture notes in electrical engineering, 2024

Research paper thumbnail of A Review of Slotted Hollow Pyramidal Absorbers for Microwave Frequency Range

Lecture notes in electrical engineering, 2024

Research paper thumbnail of Theory, Modeling, Measurement, and Testing of Electromagnetic Absorbers: A Review

physica status solidi (a)

In the era of the fifth generation (5G) and the Internet of Things (IoT), electromagnetic interfe... more In the era of the fifth generation (5G) and the Internet of Things (IoT), electromagnetic interference (EMI) poses a significant challenge. The rapid growth of wireless communication applications leads to increased electromagnetic (EM) pollution, which can have adverse health effects. To address this issue, electromagnetic absorbers (EMAs) play a critical role in eliminating EMI and reducing EM pollution between electronic devices. The focus is now on developing diverse microwave absorbing materials (MAMs) with different structures to cover a wide range of frequencies while remaining cost‐effective and effective at high angles of incidence radiation. This article comprehensively reviews EMAs, highlighting their design parameters and importance in achieving high‐efficiency absorption. The review covers absorber theory, structure, materials for various frequency ranges, and the mechanisms responsible for dissipating electromagnetic waves (EMWs). Analytical and numerical methods for mo...

Research paper thumbnail of From Rice Husk to Transparent Radiation Protection Material

Jurnal Intelek, Sep 14, 2015

Research paper thumbnail of Effects of Grain Sizes on Rice Husk Ash Composite as Microwave Absorber

Journal of physics, Aug 1, 2018

Research paper thumbnail of Effect of Bi2O3 particle sizes and addition of starch into Bi2O3–PVA composites for X-ray shielding

Applied Physics A, Aug 12, 2016

Research paper thumbnail of Radiotherapy dose verification on a customised head and neck perspex phantom

Journal of physics, May 1, 2017

Research paper thumbnail of Gafchromic XRQA-2 film for Strontium-90/Yttrium-90 (Sr-90/Y-90) Detection

Journal of Physics: Conference Series

Research paper thumbnail of Reflection technique for estimation of moisture hevea rubber latex content using rectangular patch antenna

In this paper, the designed microstrip patch antenna is employed to study reflection technique an... more In this paper, the designed microstrip patch antenna is employed to study reflection technique and predict moisture content of Hevea Rubber Latex. The rectangular patch sensor was designed to operate at microwave frequency range from 0.1 to 5 GHz on a RT/Duroid substrate with 6.15 ±0.015 permittivity and 1.27 mm thickness. The width and length of the rectangular patch antenna was 18 mm and 38 mm, respectively. The phase shift reflection coefficient, ΔӨ of rubber latex are obtained with moisture content at all selected frequencies. Estimation equations phase shift of reflection coefficient as a function of moisture content were developed at several selected frequencies. These equations were used to predict the amount of moisture content on Hevea latex based on the measured phase of reflection coefficient, ϕ using Agilent Professional Network Analyzer N5230A (PNA). The actual values of moisture content were obtained using standard oven drying method. The lowest mean relative error bet...

Research paper thumbnail of 5G Millimeter Wave Wearable Antenna: State-Of-the-Art and Current Challenges

2021 IEEE Asia-Pacific Conference on Applied Electromagnetics (APACE)

Research paper thumbnail of Trace of heavy metals in maternal and umbilical cord blood samples in association with birth outcomes in Baghdad, Iraq

EPJ Web of Conferences, 2017

Research paper thumbnail of Combined Role of Material Composition and Thickness of Activated Carbon/Natural Rubber Composite Microwave Absorbers in the Absorption of Within the 1–18 GHz Frequency Range: A Review

Lecture Notes in Electrical Engineering, 2022

Research paper thumbnail of Ultrathin Metamaterial Microwave Absorber Using Coconut Coir Fibre over X-Band Frequency Range

2019 International Conference on Communications, Signal Processing, and their Applications (ICCSPA), 2019

This paper presents the new design of simple one layer ultrathin metamaterial microwave absorber ... more This paper presents the new design of simple one layer ultrathin metamaterial microwave absorber using coconut coir fibre as the substrate. The metamaterial microwave absorber is composed of a periodic array of square loops and patches with circle cut out printed on a dielectric material which is coconut coir fibre backed by PEC. CST Microwave Studio software is used for the design and simulation over frequency range of X-Band and Ku-Band (8.2–18 GHz). From the simulation result, 90% absorption was achieved in the frequency range of 8.94 – 10.0 GHz (X-Band) with highest absorption of 99.7% at 9.37 GHz. Furthermore, the metamaterial microwave absorber has a total thickness of 1.6 mm which is only approximately 0.04λ at lowest frequency. The result shows that coconut coir fibre from the agricultural waste has a great potential to be developed further in electromagnetic wave applications particularly microwave absorber.

Research paper thumbnail of Effects of Grain Sizes on Rice Husk Ash Composite as Microwave Absorber

Journal of Physics: Conference Series, 2018

Research paper thumbnail of From Rice Husk to Transparent Radiation Protection Material

High amount of silica (SiO2) content, 99.36% was successfully prepared from Rice Husk Ash (RHA)th... more High amount of silica (SiO2) content, 99.36% was successfully prepared from Rice Husk Ash (RHA)through the burning of rice husk. Eventually, quaternary glasses were fabricated using melt quenchingtechnique based on chemical compound composition xBi2O3 - (1-x)ZnO - 0.2B2O3 - 0.3(SiO2)RHA. Thefinal thickness of glass samples prepared was within ~3.41mm. As the mole percentages of Bi2O3increased, the glass density and molar volume was also increased from 4.45 gcm-1 to 6.60 gcm-1. Theincrement is due to larger atomic number of Bi3+ compared to the Si2+, B3+ and Zn in the glass samples.However, the oxygen packing density decreased as mole percentages of Bi2O3 were increased from 240.44g-atom/l to 161.24 g-atom/l. The decreasing in oxygen packing density was due to the high non-bridgingoxygen in the glass samples. The radiation attenuation parameterization was measured using 241Am assource of gamma ray interactions at energy 59.54 keV. The mass attenuation coefficient increased from0.53cm...

Research paper thumbnail of The dose enhancement of MAGAT gel dosimeter doped with zinc oxide at 6 MV photon beam

Radiation Physics and Chemistry, 2020

Research paper thumbnail of Finite Element Analysis of Simple Rectangular Microstrip Sensor for Determination Moisture Content of Hevea Rubber Latex

Journal of Physics: Conference Series, 2018

The Finite Element Method, FEM has been successfully used to model a simple rectangular microstri... more The Finite Element Method, FEM has been successfully used to model a simple rectangular microstrip sensor to determine the moisture content of Hevea rubber latex. The FEM simulation of sensor and samples was implemented by using COMSOL Multiphysics software. The simulation includes the calculation of magnitude and phase of reflection coefficient and was compared to analytical method. The results show a good agreement in finding the magnitude and phase of reflection coefficient when compared with analytical results. Field distributions of both the unloaded sensor as well as the sensor loaded with different percentages of moisture content were visualized using FEM in conjunction with COMSOL software. The higher the amount of moisture content in the sample the more the electric loops were observed.

Research paper thumbnail of Radiotherapy dose verification on a customised head and neck perspex phantom

Journal of Physics: Conference Series, 2017

Research paper thumbnail of Optimisation of the MAGAT gel dosimeter compositions

Internatuinal Journal of Radiation Research, 2016

Research paper thumbnail of Choice of Evaluation Imaging Technique for MAGAT Polymer Gel Dosimeter

Asian Journal of Applied Sciences

_________________________________________________________________________________ ABSTRACT— The d... more _________________________________________________________________________________ ABSTRACT— The development of the polymer gel dosimeter evaluation focused mainly on magnetic resonance imaging (MRI) techniques. A new alternative imaging technique which is x-ray CT imaging has emerged from a current research. The study focused on the dose response, the dose sensitivity and the accuracy of the MAGAT gel dosimeter using two different imaging modalities. The MAGAT gel dosimeter was irradiated at 1, 5 and 10 Gy 24-h post-manufacturing. The imaging of MAGAT gel dosimeter by MRI and x-ray CT were done a day post-irradiation using an optimized protocol. The dose sensitivity of the gel obtained by the MRI technique was 0.7157 s-1 Gy-1 , whereas the dose sensitivity obtained by the x-ray CT technique was 0.6177 HGy-1. Keywords— MAGAT gel dosimeter, dose response, MRI imaging, x-ray CT