Nor zakiah Yahaya

Universiti Sains Malaysia | USM · Physics Section, School of Distance Education

There is a rising prospect for producing more efficient, widely affordable and eco-friendly microwave absorbers. Much research has demonstrated the efficacy of low-cost absorbers, particularly those made of sustainable carbonaceous and rubber-based materials structured into a hollow pyramidal shape. Natural rubber possesses outstanding resilience,...

The metaheuristic algorithm is a popular research area for solving various optimization problems. In this study, we proposed two approaches based on the Sine Cosine Algorithm (SCA), namely, modification and hybridization. First, we attempted to solve the constraints of the original SCA by developing a modified SCA (MSCA) version with an improved id...

Concrete is a common material used to build physical barrier as protection against ionized radiation. However, excessive used of concrete may lead to increase volume on mining of cement and sand, thus contribute to catastrophic on nature. This project is done to find suitable material that can replace the usage of concrete in order to build physica...

The cancer treatment modalities have been developed rapidly with the aim to maximize the absorbed dose toward the cancer cells while sparing the healthy tissues. The use of high atomic number, Z nanomaterials has become interest as it offers the possibilities such as destroying cancer tumor with minimal damage to the healthy tissues. The study aime...

The Density Functional Theory method was applied to determine muon stopping sites in [Au25(SR)18]0 nanocluster and the associated hyperfine interaction. The molecular electrostatic potential map indicates that the inner region of the Au13 icosahedron is more favorable for muon stopping sites. On the other hand, the potential in the region surroundi...

Electromagnetic interference affects human's health and interrupt the electrical equipment's performance. Metallic materials commonly used as microwave absorber is not cost-effective and too heavy. The agriculture waste from farming activities can be an alternative for inexpensive microwave absorbing material. Agriculture waste contain organic comp...

Film dosimetry is developed as a powerful tool for radiotherapy treatment verification and quality assurance. This project was done to study the response of Gafchromic EBT3® film for alpha particle detection. Gafchromic EBT3® film was exposed to alpha particle of energy 5.4 MeV from Am-241 source for different exposure time after one of the 125 μm...

Gafchromic XRQA-2 radiochromic film is an effective tool for quality assurance and dose assessment in kilovoltage radiotherapy and diagnostic applications. This work is done to study the response of Gafchromic XRQA-2 film for beta particle detection. Materials investigated are the beta particle source, Sr-90/Y-90 and Gafchromic XRQA-2 film. The fil...

The qualities of mango are affected by moisture content and storage conditions on fruits stability. Thus, the dielectric properties of maturity stages of mango were studied in this work. The dielectric constant and loss factor were measured using the commercial probe (Agilent 85070E) at microwave frequencies range (0.2 - 5 GHz), whilst the moisture...

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 an...

Trace elements are essential nutritional components in humans and inconvenient tissue content that have a significant influence on infant size. The aim of this study is to evaluate the effects of concentration of elements (uranium (U), lead (Pb) and iron (Fe)) and absorption of Pb and Fe on maternal and umbilical cord blood samples. The concentrati...

Quaternary glasses were successfully fabricated using melt quenching technique based on the chemical compound composition ((Formula presented.))Bi2O3–((Formula presented.)) ZnO–(0.2)B2O3–(0.3)SiO2, where ((Formula presented.), 0.2, 0.3, 0.4, 0.45) mole. The sources of SiO2 was produced from rice husk ash (RHA) at 99.36% of SiO2. The Urbach energy w...

IMRT dose planned for head and neck radiotherapy was verified using a customised acrylic head-and-neck phantom. The dosimeters used were calibrated Gafchromic EBT2 film and metal–oxide–semiconductor-field-effect-transistor (MOSFET). Target volumes (TV) and organs-at-risk (OAR) which were previously contoured by an oncologist on selected nasopharynx...

Background: An effective polymer gel dosimeter can be fabricated by varying the composition of its chemical components. Materials and Methods: The MAGAT gel dosimeter formulations that used different compositions of Methacrylic acid (MAA) and gelatin were extensively investigated in the present study according to the R2-dose response and R2-dose se...

The effect of Bi2O3 particle sizes filled PVA composites on X-ray transmission for X-ray shielding purpose had been successfully fabricated and analyzed by using X-ray fluorescent spectroscopy (XRF) and mammography units with various low X-ray energy ranges. Besides, a preliminary investigation was carried out by using XRF unit to obtain the effect...

Polymer gel dosimeter is a radiation sensitive chemical dosimeter that can measure 3D dose distribution with high resolution. Due to the increasing complexity of radiotherapy treatment planning and delivery, accurate experimental radiation dosimetry plays an important role in the implementation and quality assurance of new treatment techniques. A p...

— In rubber industry, the price of Hevea latex depends on the percentage of moisture content. Since water occurs on most materials in nature as a natural component of the material or is introduced during technologies processes, it is quite obvious that mesasurement and control of moisture content have great economic and technical importance. Thus,...

_________________________________________________________________________________ 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,...

_________________________________________________________________________________ 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,...

A simple rectangular microstrip sensor for determination of moisture content in Hevea Rubber Latex is presented in this paper. The microstrip patch sensor was designed to operate at microwave frequency range from 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 an...

The commercial open-ended coaxial probe (Agilent 85070E) is the most commonly used sensor to determine the permittivity of wet materials. This paper extends the usability and applicability of the sensor to the estimation of moisture content in Hevea Rubber Latex. The dielectric constant and loss factor were measured using the commercial probe whils...

The primary goal of radiation therapy is to deliver a sufficient radiation dose to a target volume while minimizing the dose to surrounding healthy tissue. In this study the dose response of methacrylic acid-gelatin (MAG) polymer gel dosimeter using different type of anti-oxidants; ascorbic acid (AscA) and tetrakis-hydroxy-methyl-phosphonium chlori...

This paper presents an intercomparison between the finite element method, method of moment, and the variational method to determine the effect of moisture content on the resonant frequency shift of a microstrip patch loaded with wet material. The samples selected for this study were Hevea rubber latex with different percentages of moisture content...

The primary goal of radiation therapy is to deliver a sufficient radiation dose to a target volume while minimizing the dose to surrounding healthy tissue. In this study the dose response of methacrylic acid-gelatin (MAG) polymer gel dosimeter using different type of anti-oxidants; ascorbic acid (AscA) and tetrakis-hydroxy-methyl-phosphonium chlori...

This paper describes the application of a SMA stub contact panel as an insulated monopole sensor for determination of moisture content in hevea rubber latex. Comparison results between measured and calculated reflection coefficient using King’s model are presented. Calibration equations relating moisture content to phase shift have been established...

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 t...

A microstrip patch sensor for determination of moisture content in Hevea Rubber Latex is presented in this paper. The microstrip 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 per-mittivity and 1.27 mm thickness. The width and length of the rectangular patch antenna was...