Displaying publications 1 - 20 of 209 in total

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  1. Faizal Mohamed, Irman Abdul Rahman, Ngu, Thieng Kui, Syazwani Mohd Fadzil, Firdaus Pozi, Amran Ab. Majid, et al.
    MyJurnal
    Electricity has become one of the necessities for human daily activities. The presence of electric
    current produces electromagnetic fields (EMF) at extremely low frequency (ELF). The problem arises
    when scientists suggests a possible connection between ELF exposure to human health and safety.
    Concerned about the safety and health of students and staff, Universiti Kebangsaan Malaysia (UKM)
    took the initiative to identify possible ELF sources and measure their exposure in various locations
    around the UKM main campus in Bangi. This paper reports the results obtained from the monitoring
    of the magnetic flux density at three identified locations in the vicinity of the overhead high-voltage
    transmission line which transverses the university compound and compare the maximum value results
    with the exposure limit suggested by the International Committee on Non Ionising Radiation
    Protection (ICNIRP) for ELF. Measurements were done with an (Extech) Three Axis
    Electromagnetic Field (EMF) Meter (Model 430826) to determine the magnetic flux density. The
    lateral profile method was applied as the standard measurement methodology. Results showed that the
    maximum value of the magnetic flux density was 12.5 mG, which is below the suggested ICNIRP
    public exposure limit of 1000 mG, or in percentage ratio, 1.25% of ICNIRP public exposure limit.
    Results from the statistical Kruskal-Wallis test showed that there is a significant difference in the
    distributions of the magnetic flux densities at the different locations (P < 0.05). In conclusion, the
    measured locations are still safe for people in short-term exposure. However, long-term exposure
    measurements still need to be done to provide concrete data on the ELF-emission levels in UKM.
  2. Abdul Hannan Damahuri, Hassan Mohamed, Abdul Aziz Mohamed
    MyJurnal
    Thorium is a fertile material that can undergo transmutation for it to become a fissile material,
    uranium-233. The fissile material can go through a fission process in order to generate heat energy
    and eventually electricity. Most nuclear reactors use uranium as their fission source. The use of
    thorium as nuclear fuel has been only investigated for few types of reactors such as a high, temperature
    gas reactor (HTGR), fast breeder reactor, light water reactor (LWR) and heavy water reactor
    (HWR). For research reactors specifically, there are limited academic publications related to the
    la,test u.se of thorium. Hence, the main, interest, of this work is to compile and review the latest
    academic publications related to the active use of thorium, for research reactors in particular. The
    reviewed studies have been, divided into two categories which are experimented and simulation projects.
    The experimental projects are a,bold the ongoing thorium fuel tests that have been carried out. in an
    actual, research reactor. On the hand, the simulation work: is related to the computational analysis
    performed in predicting the neutronic behaviour of thorium based fuel in research reactors. The
    experimented study of thorium is currently active for the KAMINI research reactor. Additionally, most,
    simulation works focus on finding criticality and neutron spectra.
  3. Faizal Mohamed
    MyJurnal
    The effects of radiation on tissue have generally been investigated in the context of therapeutic
    irradiations, radiation protection and exposure to solar radiation. Typically attention has
    concentrated primarily on cells, less consideration being given to the extracellular matrix (ECM).
    ECM consists of collagen and elastin fibers immersed in a viscoelastic gel composed principally of
    hyaluronan (HA) and proteoglycans. The present study examines changes in the physical properties of
    the principle matrix micromolecules due to exposure to ionizing radiation. Freeze-dried rooster-comb
    HA (Sigma) were used to give doses of 10-100 Gy for HA, to cover the range of irradiation exposure
    during radiotherapy. The viscosity of HA (at 1.25% and 0.125% w/v) was measured by both cone and
    plate and capillary viscometry, the former providing measurement at uniform shear rate and the latter
    providing a more sensitive indication of changes. The Raman microspectrometry was employed to
    characterize these changes on ECM molecular conformation. In regard to the viscometry, both
    techniques (cone and plate and capillary viscometry) reveal a dose-dependent reduction in viscosity
    (from 340 ± 194 cP for controls to 1500 ± 88 cP at a shear rate of 2 s-1 and dose of 75 Gy), again
    suggesting depolymerisation.
  4. Faizal Mohamed
    MyJurnal
    The extracellular matrix (ECM) is a complex structural entity surrounding and supporting cells that
    are found within mammalian tissue. This study presents the effect of ionizing radiation on the physical
    properties of elastin which is usually found within arteries, lung, skin, ligantum nuchae, vocal chords
    and elastic cartilage as a function of their composition and organization or architecture. X-ray from
    an electron linac were used to give doses of 10-50Gy to cover the range of irradiation exposure during
    radiotherapy. A uniaxial mechanical testing protocol was used to characterize the fibrous protein. For
    pericardial the major change was an increase in the elastic modulus in the toe region of the curve (≤
    20% strain), from 23±18 kPa for controls to 57±22 kPa at a dose of 10 Gy (p=0.01, α=0.05). At a
    larger strain (≤ 20%), the elastic modulus in the region decreased from 1.92±0.70 MPa for control
    pericardium tissue to 1.31±0.56 MPa (p=0.01, α=0.05) for 10 Gy X-irradiated sample. For elastin,
    the stress-strain relationship was linear up to 30% strain, but the elastic modulus decreased
    significantly with irradiation (controls 626±65 kPa, irradiated 474±121 kPa (p=0.02, α=0.05). The
    results suggest that for elastin chain scissions are the primary effect of irradiation. The Raman
    microspectrometry was employed to characterize these changes on ECM conformation.
  5. Zainah Adam, Shafii Khamis, Amin Ismail, Muhajir Hamid
    MyJurnal
    Ficus deltoidea or locally known as Mas cotek is one of the common medicinal plants used in
    Malaysia. Our previous studies showed that this plant have blood glucose lowering effect. Glucose
    uptake into muscle and adipocytes cells is one of the known mechanisms of blood glucose lowering
    effect. This study was performed to evaluate the effect of Ficus deltoidea on glucose uptake activity
    into muscle cells. The cells were incubated with Ficus deltoidea extracts either a,lone or combination
    with insulin. Amount of glucose uptake by L6 myotubes was determined using glucose tracer, 2-deoxy-
    [l-:-Hj-glucose. The results showed that Ficus deltoidea extracts at particular doses enhanced basal or
    insulin-mediated glucose uptake into muscle cells significantly. Hot aqueous extract enhanced glucose
    uptake at the low concentration (10 pg/ml) whereas methanolic extract enhanced basal glucose uptake
    at high concentrations (500 and 1000 fig/ml). Meanwhile, ethanolic extract enhanced glucose uptake at
    low and high concentrations. Methanolic extract also mimicked insulin activity during enhancing
    glucose uptake into L6 muscle cells. Glucose uptake activity of Ficus deltoidea could be attributed by
    the phenolic compounds presence in the plant. This study had shown that Ficus deltoidea has the
    ability to enhance glucose uptake into muscle cells which is partly contributed the antidiabetic activity
    of this plant.
  6. Muhammad Fakhrurazi Ahmad Fadzil, Ng Yen, Siti Najila Mohd Janib, Noor Hasnah M. Khairullah, Mohd Khairul Najah
    MyJurnal
    PET/CT Scan with obGa-labelled analogs is of increasing interest in Nuclear Medicine and currently
    is being performed all over the world. However, such labeling procedure requires high purity and
    concentrated solutions of°sGa. Here we report the purification and concentration of the eluate of
    SnOi-Based obGe/obGa generators via the anion exchange method. Three different anion columns were
    selected to purify and concentrate the6SGa eluat.es which are Chromafix, Oasis WAX and AG 1-X8
    columns. The different anion columns were compared and evaluated in terms of their capability in
    adsorption and desorption of ""Ga from, the generator. While the optimum molarity of Hydrocholric
    Acid (HCl) for highest 6dGa retention was also determined starting from the ranges of fM to 7M of
    HCl. The results showed that the percentage of 68Ga retention or adsorption .started to be plateau at
    molarity of 5.5M for all three anion cartridges. One-way ANOVA analysis proved that there is no
    significant difference between 5.5M with 6.0M, 6.5M and 7.0M which means that the retention of
    gallium-68 is equal at those molarities. At 5.5M, Chromafix and Oasis WAX cartridges showed the
    highest retention of gallium-68 which is 98.30%. The lowest 6"Ga retention was gained by AG 1-X8
    column which is 97.07%'. While for desorption of 6bGa, the highest percentage was obtained by using
    Oasis WAX cart/ridges which, is 70.f9% followed by Chromafix which, is 70.36%. The lowest desorption
    of gallium-68 was obtained by using AG 1-X8 column which is only 58.56%. Therefore, from this
    study, the most suitable cartridge and HCl molarity that should be applied in purification and
    concentration of Gallium-68 eluate fromÿ a SnOs Based °*Ge/*Ga generator is Oasis® WAX column
    with a HCl molarity of 5.5M respectively.
  7. Chee, Fuei Pien, Saafie Salleh, Afishah Alias, Haider F. Abdul Amir, Abu Hassan Husin
    MyJurnal
    The most sensitive part of a metal-oxide-semiconductor (MOS) structure to ionizing radiation is the
    oxide insulating layer. When ionizing radiation passes through the oxide, the energy deposited creates
    electron/hole pairs. Oxide trapped charge causes a negative shift in capacitance-voltage (C-V)
    characteristics. These changes are the results of, firstly, incre using trapped positive charge in the
    oxide, which causes a parallel shift of the curve to more negative voltages, and secondly, increasing
    interface trap density, which causes the curve to stretch-out.
  8. Mohd Rafi Mohd Solleh, Abdul Aziz Mohamed, Abd. Aziz Tajuddin, Faridah Idris, Mohamad Hairie Rabir, Muhammad Rawi Md Zin, et al.
    MyJurnal
    Thermal neutron beam from thermal column was selected for a Boron Neutron Capture Therapy
    (BNCT) system utilizing the Malaysian TRIGA MARK II reactor. Determination of shielding
    materials for fast and epithermal neutron was conducted. The materials selected were polyethylene,
    paraffin and water. For gamma-ray shielding, lead was used. The objective of this paper is to present
    the simulation and verification of an optimal design of BNCT collimation at a beam. line viewing the
    thermal column. A collimator was made from polyethylene pipe with 8 cm of diameter filled with
    paraffin.
  9. Faridah Mohamad Idris, Wan Ahmad Tajuddin Wan Abdullah, Zainol Abidin Ibrahim, Zulidza Zulkaply, Zukhaimira Zolkapli
    MyJurnal
    In the an electron-proton collider, neutral hadrons were produced in the hadronisation process that
    occurred just after the electron-proton collision. The neutral hadrons were produced at interaction
    point using reference energy from its centre-of-mass. In this paper, we discuss the kinematics of
    particles produced from its centre-of-mass and the hadronisation process follows after such collision.
  10. Nurin Irdina Binti Mohd Anuar, Asyraf Arif, Abdul Aziz Mohamed, Mohamad Hairie Rabir, Faridah Mohamad Idris, Muhammad Rawi Md Zin
    MyJurnal
    In order to prepare Malaysia to be nuclear ready, the Malaysian 1 MW TRIGA MARK II research
    reactor (RTP) located at the Malaysian Nuclear Agency was premeditated with the aim to effectually
    actualize the multitude areas of basic nuclear research, labor training and education. To meet the
    modern safety standards, analyses of a strong interaction between the thermal-hydraulic system
    behavior and the space-dependent neutron kinetics are needed as mere thermal-hydraulics codes are
    said to be incapable to succeed the present safety standards. This could be achieved through the
    coupling of neutronic and thermal-hydraulic codes of the reactor. Previous studies had shown that the
    coupled codes are able to successfully be employed for the correlation between thermal-hydraulic
    analysis and neutron kinetics at transient and steady state. In this study, the coupling was achieved
    through MCNP and TRIGLAV codes for neutronic and thermal-hydraulic respectively. Core-15 of
    RTP was modeled for both of the codes; hence calculating the criticality, analysis of power and
    neutron flux distribution. The consistency and accuracy of the developed Core-15 MCNP model was
    established by comparing calculations to the experimental results and TRIGLAV code. The criticality
    predictions for both codes are in very good agreement with the experimental results. The core reached
    its criticality after 66 fuels. The highest hot rod power peaking factor was found to be 1.28. The
    results are conservative and can be applied to show the reliability of MCNP and TRIGLAV codes.
  11. Mohamad Awais, A. Syafiq Ramli, Abdul Aziz Mohamed, Megat Harun M.A., Azraf Azman, M. Rawi Md Zin, et al.
    MyJurnal
    This work main aim is to study the analysis of slow neutrons which include thermal and
    epithermal neutrons and also analysis on fast neutrons. The outcome from this work showed that
    the comparison result between fast and slow neutrons. The safety assessment at reactor TRIGA
    FUSFATI (RTF) is one of the main objectives of the work and there is a detailed discussion on it
    which helped in accomplishing the task. Gamma Rays produced in this experiment was high and in
    the experiment and it is realized that the shielding plays a vital role in the success of this
    experiment which prevents all the radiations. From the results of the experiment it is realized that
    these gamma rays are not suitable for the application of Boron Neutron Capture Therapy
    (BNCT). However, these radiations are suitable for the application of Neutron Radiography (NR).
    The study on this work will help in study of nuclear applications such as BNCT, NR, SANS etc.
    These applications are using in medical and nuclear fields. The electronic device used in the
    experiment to detect neutron is Neutron Spectrometer. The results from Neutron Spectrometer
    and TLDs are very similar which showed that the experiment is a success. Numerical results were
    compared with those available in literature for validation.
  12. Rashid, F.I.A., Chaculi, F.S.M., Zolkaffly, M.Z., Sali, S.S.M., Jamal, N.
    MyJurnal
    There is a growing interest from, newcomer countries to utilise nuclear energy for electricity
    generation. The International Atomic. Energy Agency (IAEA) has developed two methodologies,
    namely, the IAEA Milestone Approach and the International Project on Innovative Nuclear Reactors
    and Fuel Cycles (INPRO) Methodology to help its Member States in assessing the viability of nuclear
    power programme (NPP) and nuclear energy system. This paper highlights important features of both
    methodologies in supporting deployment of nuclear power programme for a newcomer country. In
    summary, the IAEA Milestone Approach focuses for near term while the INPRO Methodology focuses
    for long term assessment to support the deployment of first NPP in newcomer countries. Depending
    on newcomer country's priority and resources, both methodologies can be performed either separately
    or in-parallel.
  13. Nur Syazwani Mohd Ali, Khaidzir Hamzah, Rafhayudi Jamro
    MyJurnal
    One of the major component in neutron radiography is a collimator that is used to collimate the neutron in parallel beam with less gamma ray contamination and high thermal neutron flux. The collimator consists of seven components and the interest component is an aperture as it is used to prevent the thermal neutron from entering the beam except through the center hole. In this study, the collimator design was taken from radial beam port at NR facilities at ANM with the collimation ratio is 46.4. In order to increase the collimation ratio, optimization of the aperture component has been done on four different material and 1-5 cm diameter parameters. The optimization of apertures shows that the cadmium with 1 cm diameter yields the thermal neutron flux at the collimator inlet and outlet with 1.78 x103 n cm-2 s-1 and 5.90 x102 n cm-2 s-1 while the gamma ray contamination was 10.7 μSv hr-1. The optimization succeed to produce high L/D ratio however the thermal flux was low and the gamma contamination was higher that original design but satisfied the ICRP 74 condition for radiation worker.
  14. Julie Andrianny Murshidi, Siti Mariam Mohamad, Choo, Thye Foo, Nurazila Mat Zali, Che Seman Mahmood
    MyJurnal
    Structural and dielectric properties of barium strontium, titanate (Ba(ÿ)SrxTiO$) ceramics with x—
    0.25, 0.5 and 0.75 were investigated. The Ba(i-xjSrxTiOs ceramics were synthesised by solid state
    reaction method. Microstructure, surface morphology and dielectric properties of the synthesised
    ceramics were examined using XRD, SEM and Impedance Spectroscopy respectively. XRD results
    revealed that all samples contained BaTiOg as primary phase with tetragonal perovskite crystal
    structure. The crystallite size slightly increased with the increasing of Sr contents. SEM micrographs
    showed that the microstructure become denser when Sr contents increased. Impedance spectroscopy
    showed dielectric constant for all samples were decreased with increasing temperature up to 200°C.
  15. Nur Azna Mahmud, Zalina Laili, Ramlah Tajuddin
    MyJurnal
    This study focused, on the activity concentration and radiation hazard assessment of radionuclide in
    bricks. The activity concentrations per unit of mass in the studied bricks ranged from 59.82 to 236.65
    Bqkg'1 for Ra-226, from 66.29 to 185-4 Bqkg'1 for Th-232, and from 283.50 to 1599.67 Bqkg'1for K-fO.
    In terms of radiation hazard assessment, granite bricks exceeded the allowance limit stated by Nuclear
    Energy Agency -Organisation for Economic Co-operation & Development (NEA-OECD) in radiumequilibrium
    activity (Req), External Hazard Index (Hex), Internal Hazard Index (Hin) and
    Representative Level Index (Iw). Thus, this has proof that the naturally occurring radionuclide
    materials present in the brick have a potential in effecting the dwellers health.
  16. Abdul Aziz Mohamed, Hafizal Yazid, Megat Harun, M.A.
    MyJurnal
    Thermoplastic natural rubber sample is found isotropic based on Small Angle X-Ray Scattering (SAXS) pattern. Morphological interpretation was deduced based on ideal lamellar morphology using 1-D correlation function. The fitting was carried out using Porod tail model and Vonk for backextrapolated model. It is found that the long period value is 15. 7nm which is comparable to results obtained from Lorenzt corrected profile, 20nm. Crystalline thickness and amorphous thickness was found as 13.4 and 2.31nm respectively.
  17. Yavar, A.R., Sarmani, S.B., Khalafi, H., Wood, A.K., Khoo, K.S.
    MyJurnal
    Present work shows the development of nuclear technology in Malaysia and highlights its
    applications that have been developed by using the instrumental neutron activation analysis
    (INAA) method. In addition, present study exhibits a comprehensive review of INAA for
    calculation of neutron flux parameters and concentration of elements. The INAA is a
    powerful method to analyse the sample which identifies qualitative and quantitative of
    elements present in a sample. The INAA is a working instrument with advantages of
    experimental simplicity, high accuracy, excellent flexibility with respect to irradiation and
    counting conditions, and suitability for computerization. In INAA, sample is irradiated and
    measured directly. In practical. INAA is based on an absolute, relative and single-comparator
    standardisation method. The INAA has been developed since 1982 when the
    TRIGA Mark II reactor of Malaysia has commissioned. The absolute method was less
    utilised, the relative method has been used since 1982, and the ko-INAA method is derived
    from single-comparator standardization method has been developed since 1996 in Malaysia.
    The relative method, because of its advantages, such as high accuracy, easy for using, has
    many applications in Malaysia. Currently, local universities and Malaysian Nuclear Agency
    (MNA) research reactor use INAA method in Malaysia.
  18. Abubaker Ali Yousif, Ismail Bahari, Muhamad Samudi Yasir
    MyJurnal
    To quantify the effectiveness of deuterons and helium particles at low doses, the inactivation rate in
    vitro for V79 cells has been extracted from radiobiological published data. The Physical parameters
    characteristics of these charged particles such as the linear energy transfer, the restricted linear
    energy transfer, the linear primary ionization and the mean free path are determined. The
    relationship between the inactivation rate and the physical parameters for deuterons and heluim-3
    particles has been established in this research. This approach enables in getting the distinctive
    biological response in terms of varies physical quality parameters. The best statistical regression
    fittings are formulated for each correlation.
  19. Muhammad Afiq Khairil Anuar, Siti Zanariah Ab Aziz, Raizulnasuha Abdul Rashid, Safri Zainal Abidin, Norhayati Dollah, Wan Nordiana A. Abd Rahman
    MyJurnal
    Radiotherapy has become the most important modality in treating cancer with approximately 50% of
    cancer patient undergo the treatment. However, more improvement to the radiotherapy treatment
    efficacy is required to deprive cancer. Assessment of tumor progress during treatment is important, to
    accommodate the changes that occur during the fractionation course. The objective of this study is to
    assess tumor cell damage after external beam radiotherapy by using technetium-99m
    pertechnetate (99mTcOf) as a tracer. In this study, HeLa cells were irradiated with 6 MVphoton beam
    with different radiation dose ranging from 0.5 Gy to 10 Gy. The irradiated cells were recultured in 6-
    well plates and incubated for 10 days. After that, 2 mCi of 99mTcOf were prescribed to each cell
    colonies. The viable cells were separated from the rest, and measured for 99mTcOf uptake using singlehead
    gamma camera with LEHR collimation. As results, the cells survival, fractions clearly indicate
    diminishing effect, to the cells at, higher dose of irradiation. Good correlation were observed between
    mmTcGi uptake and survival, fraction for cells irradiated at, lower dose and less significant, correlation
    were indicated at higher dose. In conclusion, there is potential for the efficacy of external beam
    radiotherapy in treating cancer to be assessed by using radioisotope as a non-invasive tracer. In this
    case, technetium-99m, pertechnetate (99mTcOjt) could be attached to the specific antibody so that, better
    correlation, between, the cells uptake and possible cell damages could be observed.
  20. Safri Zainal Abidin, Raizulnasuha Abdul Rashid, Muhammad Afiq Khairil Anuar, Wan Nordiana A. Abd Rahman
    MyJurnal
    The purpose of this study is to determine the technetium-99m pertechnetate (99mTcO4) intercellular uptake by different types of cell lines. HeLa, human fetal
    osteoblast (hFOB), glial and glioma cell lines grown in 6-wells culture plates were incubated with 99mTcO4 of activity of 200, 400, 600. 800 and 1000
    pCi for 30 minutes at 3T°C and 5% ( '< - humidified atmosphere. After incubation, the cells were washed 3 times with phosphate buffer saline to remove the
    extracellular traces of 99mTcO4. Measurements of the intercellular Q9mTcOjt radioactivity were performed using single head gamma
    camera and the percentage uptake of the yUwTcGpinto the cells was calculated. The intercellular uptake
    0fyUmTcO_( was found to be inversely correlate to the radioactivity HeLa cell shows the highest uptake
    followed by hFOB, glial and glioma cell lines. Comparison of uptake between normal and cancer cells
    present indistinguishable results. The findings of this study suggest that the intercellular uptake of
    yymTcOjt is highly dependent on the type of cells despite no significant different of uptake was found
    between normal and cancer cell lines. The level of radioactivity is also an important determinant
    factor that influence the uptake ofyUmTcG) into the cells. This study will be the first precedent toward
    understanding the cellular characteristic and pharmacokinetic of non-invasive imaging tracer for
    future molecular imaging and therapy.
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