Displaying publications 1 - 20 of 95 in total

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  1. Nazaratul Ashifa Abdullah Salim, Nur AfiqahHarun, Zainon Othman, Salmah Moosa, Siti Aminah Omar, Muhammad Azfar Azman, et al.
    MyJurnal
    For addressing the issue of adulteration and counterfeiting of the sources of origin for the edible bird’s nests (EBNs), a preliminary study of elemental characterization for their geochemical markers was performed. This study aims to characterize the elemental profiles as geochemical markers and evaluate the relationships between these markers which could be used for the verification of the geographical origin of EBN in Malaysia. EBN samples from house and cave nests that represent a range of geographical and environmental characteristics were analysed using Neutron Activation Analysis (NAA) technique. The method was validated by analysing the Standard Reference Material SRM-1515 (Apple Leaves) and SRM-1573a (Tomato Leaves) of NIST. A total of 18 elements were determined. The results showed a statistical analysis of one way ANOVA has proven that there have a significant different elemental profiles in both EBN, clearly V, As, Ba, Sc, Sm and Th were not detectable in the house EBNs. Therefore, initial finding could be concluded that those elements can be identified as the key elements for geochemical marker to differentiate the type of EBN. Furthermore the differnces probably due to natural presence of those elements as well as regional or location and seasonal variation factors affecting the dietry habits of the swiftlets.
  2. Phillip, Esther, Muhamad SamudiYasir, Muhamat Omar, Mohd Zaidi Ibrahim, Zalina Laili
    MyJurnal
    Effect of washing solutions’ pH on removal of radium-226 from radium-contaminated soil using distilled water and humic acid extracted from Malaysian peat soil was studied by a single batch washing method. The study encompassed the extraction of humic acid and the washing of radium-contaminated soil using distilled water and humic acid solutions of varying pH in the range between 3 to 11. Activity of radium-226 was determined by gamma spectrometer. In the pH range studied, the removal of radium-226 was greater when humic acid solutions were used compared to distilled water. Greater removal of radium-226 was obtained using highly basic pH washing solutions compared to neutral and acidic solutions.
  3. Mei-Wo Yii, Zal U'yun Wan Mahmood
    MyJurnal
    Natural radioactivityin thesurface soil from thevicinity of Lynas Rare-earth plantin Kuantan, Pahanghad been studied with aim of evaluating environmental radioacitivityof thatarea. The radioactivities of the samples have been measured usinga low-background HPGe gamma detector. The concentration of 226Ra ranged found to be between 8.7 –76.9 Bq/kg (mean 33.7 Bq/kg); activity of 238U from 8.7 to 80.5 Bq/kg (mean 36.9 Bq/kg); as for 232Th, it ranged from 6.2 to 121.5 Bq/kg(mean 58.2 Bq/kg)and that of 40K,the values was from 19.1 to 778.9 Bq/kg (mean of 221.3 Bq/kg). Activity standard deviation for226Ra, 238U, 232Th and 40K were 14.2 Bq/kg, 14.7 Bq/kg, 26.1 Bq/kg and 185.6 Bq/kg, respectively. To evaluate the risk of radiation hazard to human, several parameters, i.e. the radium equivalent activity, External hazard index, Representative level index and dose rate in air from the terrestrial natural gamma radiation were calculatedwith the mean valuesfound to be136.7 Bq/kg, 0.4, 1.0, 65 nGy/h, respectively. The data were discussed and compared with those obtained from the previous studies given in the literatures. Thisstudy found that themean dose equivalent received by an individual at the vicinity area (outdoor) of Lynas plant was estimated to be 82.0 Sv/yr, whichis far below the annual dose limitof1,000 Sv/yrfor general public as stipulated in the national act.
  4. Zaidi Embong
    MyJurnal
    This review briefly describes some of the techniques available for analysing surfaces and illustrates their usefulness with a few examples such as a metal and alloy. In particular, Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and laser Raman spectroscopy are all described as advanced surface analytical techniques. In analysing a surface, AES and XPS would normally be considered first, with AES being applied where high spatial resolution is required and XPS where chemical state information is needed. Laser Raman spectroscopy is useful for determining molecular bonding. A combination of XPS, AES and Laser Raman spectroscopy can give quantitative analysis from the top few atomic layers with a lateral spatial resolution of
  5. Wo, Yii Mei, Hidayah Shahar, Zaharudin Ahmad
    MyJurnal
    Present of 241Am in the environment is being determined as part of surveillance and research
    programs related to nuclear activities. The separation of 241Am from environmental samples was
    carried out against the IAEA’s reference material by using an improved in-house radiochemical
    separation method through anion exchange column, followed by the electro-deposition on a
    stainless steel disc, and finally assayed on alpha spectrometry counting system. The resulting
    spectra showed good isolated peak, indicating a good separation of the radionuclide of interest.
    The analytical results were in good agreement with the certified value for IAEA-326 and IAEA-368
    with the calculated U-score was 0.36 and 0.82, respectively, showing no significant difference
    between the experimental and certified value. Using this method, distributions of 241Am in seabed
    surface sediment in the Exclusive Economic Zone of East Coast Peninsular Malaysia were studied.
    Samples were collected during June 2008 where the concentrations of 241Am were found to be
    ranged from < 0.08 to 0.36 Bq/kg, dry weight.
  6. Shakinah Salleh, Zaiton Ahmad, Affrida Abu Hassan, Yahya Awang, Yutaka Oono
    MyJurnal
    Chrysanthemum morifolium is an important temperate cut flower for Malaysian floriculture
    industry and the lack of new local owned varieties led to this mutation breeding research. The
    objective of this study was to compare the effectiveness of ion beam irradiation in generating
    mutations on ray florets and nodal explants of Chrysanthemum morifolium cv. ‘Reagan Red’. Ion
    beams has become an efficient physical mutagen for mutation breeding. The ray florets and nodal
    explants were irradiated with ion beams at doses 0, 0.5, 1.0, 2.0, 3.0, 5.0, 8.0, 10, 15, 20 and 30 Gy.
    The 50% of in vitro shoot regeneration (RD50) for ray florets explants was 2.0 Gy and for nodal
    explants was 4.0 Gy. Thus, relative biological effectiveness (RBE) for ray florets was found 2.0
    times higher than the nodal explants. The regenerated plantlets were planted in the greenhouse at
    MARDI, Cameron Highlands for morphological screening. Overall performance of survival
    plantlets derived from in vitro nodal and ray floret explants was recorded. The characters studied
    include plant morphology and flowering characteristic. The ray florets explants were found to be
    more sensitive to ion beam irradiation and generated more mutations as compared to nodal
    explants.
  7. Mohd Reusmaazran Yusof, Yusof Abdullah
    MyJurnal
    Nuclear grade (high-purity) graphite for fuel element and moderator material in Advanced Gas
    Cooling Reactors (AGR) displays large scatter in strength and a non-linear stress-strain response from the damage accumulation. These responses can be characterized as quasi-brittle behaviour. Current assessments of fracture in core graphite components are based on the linear elastic approximation and thus represent a major assumption. The quasi-brittle behaviour gives challenge to assess the real nuclear graphite component. The selected test method would help to bridge the gap between microscale to macro-scale in real reactor component. The small scale tests presented here can contribute some statistical data to manifests the failure in real component. The evaluation and choice of different solution design of biaxial test will be discussed in this paper. The ball on-three ball test method was used for assessment test follows by numerous of analytical method. The results shown that biaxial strength of the EY9 grade graphite depends on the method used for evaluation. Some of the analytical methods use to calculate biaxial strength were found not to be valid and therefore should not be used to assess the mechanical properties of nuclear graphite.
  8. Nolida Yussup, Nur Aira Abd. Rahman, Ismail Mustapha, Jaafar Abdullah, Mohd. Ashhar Khalid, Hearie Hassan, et al.
    MyJurnal
    Data transmission in field works especially that is related to industry, gas and chemical is paramount importance to ensure data accuracy and delivery time. A development of wireless detector system for remote data acquisition to be applied in conducting fieldwork in industry is described in this paper. A wireless communication which is applied in the project development is a viable and cost-effective method of transmitting data from the detector to the laptop on the site to facilitate data storage and analysis automatically, which can be used in various applications such as column scanning. The project involves hardware design for the detector and electronics parts besides programming for control board and user interface. A prototype of a wireless gamma scintillation detector is developed with capabilities of transmitting data to computer via radio frequency (RF) and recording the data within the 433MHz band at baud rate of 19200.
  9. Lombigit, Lojius, Maslina Ibrahim, Nolida Yusup, Nur Aira Abdul Rahman, Yong, Chong Fong
    MyJurnal
    Pulse Shaping Amplifier (PSA) is an essential component in nuclear spectroscopy system. This
    amplifier has two functions; to shape the output pulse and performs noise filtering. In this paper,
    we describe the procedure for the design and development of a pulse shaping amplifier which can
    be used in a nuclear spectroscopy system. This prototype was developed using high performance
    electronics devices and assembled on a FR4 type printed circuit board. Performance of this
    prototype was tested by comparing it with an equivalent commercial spectroscopy amplifier (Model
    Silena 7611). The test results showed that the performance of this prototype was comparable
    to the commercial spectroscopic amplifier.
  10. Raizulnasuha Ab Rashid, Nurhikmah Azam, Norhayati Dollah, Wan Nordiana W Abd Rahman
    MyJurnal
    The purpose of the study was to determine the effect of out-of-field photon beams radiotherapy to the cancer cell survival. In this study, HeLa and T24 cancer cells were irradiated with 6 MV and 10 MV photon beams in two different conditions, one with intercellular communication with the in-field cell and one without the communication. Cells survival was determined by clonogenic assay. In the presence of intercellular communication, the cell death was increased which indicate the presence of radiation induced bystander effects (RIBE). The effects were also dependent on the cell types and photon energy where the HeLa cells exhibit less survival compares to T24 cells and the effects were prominent at higher photon energy. This study demonstrates that the out-of-field cells in conjunction with RIBE plays important roles in the cells response towards megavoltage photon beam radiation therapy.
  11. Shaiful Azuar Mohamad, Nurul Shahnadz Amir Hamzah, Mohd Yusof Hamzah, Rusli Ibrahim, Khairuddin Abd Rahim, Choong, Yew Keong, et al.
    MyJurnal
    The fermentation of Pleurotus pulmonarius (non-irradiated) and Pleurotus pulmonarius (irradiated) were carried out in Erlenmeyer flask 500 mL (working volume 250 mL) and screened for the presence of β-glucan (1, 3:1, 6). The biomass obtained was extracted using Modified Mizuno Method to get the endopolysaccharide. The endopolysaccharides of Pleurotus pulmonarius (irradiated) contained higher content of β-glucan (1, 3:1, 6) with 16.7 g/100g crude polysaccharide compared to the non-irradiated strain. The irradiated strain was chosen for further investigation. Fractionation of endopolysaccharide Pleurotus pulmonarius (irradiated) using column chromatograph yielded 7 fractions. The first fraction (F1) contained high molecular weight fraction ~ 105 Da which potential immunomodulation characteristics. The Pleurotus pulmonarius (irradiated) was produced in a 5 L air-lift bioreactor. The highest biomass was obtained at air flowrate of 2 L/min, yielding productivity of 2.56 g/L.d.
  12. Norhayati Abdullah, Wong, Jeannie Hsiu Ding, Ng, Kwan Hoong, Ung, Ngie Min
    MyJurnal
    The assessment of surface dose is essential in radiotherapy to avoid deterministic effect or to
    reduce the severity of side effects from radiation treatment. In this study, the surface dose for breast
    cancer radiotherapy was measured using two types of dosimeter; Thermoluminescent Dosimeter
    (TLD) and Optically Stimulated Luminescent Dosimeter (OSLD). The study was performed on the
    left breast of female Alderson Radiation Therapy (ART) phantom. The treatment planning was
    carried out on the ART phantom to determine the homogeneity of dose distribution within the target
    organ is complied with the tolerance limits of 95% to 107% as recommended by the International
    Commission on Radiation Units and Measurements (ICRU)’s Report No. 50. From the treatment
    planning result, the phantom then was irradiated with 267 cGy dose per fraction for two beam
    fields; medial tangential and lateral tangential fields using a 6 MV photon beam produced from
    three-dimensional (3D) conformal radiotherapy. Result shows that the OSLD provides 25.7% and
    23.5% higher surface dose compared to TLD for medial tangential and lateral tangential fields,
    respectively. This condition may be due to higher effective point of measurement and angular
    dependence of the OSLD compared to TLD. As a conclusion, suitable dosimeter should be selected
    to ensure accurate estimation of surface dose could be made thus reduction of skin reaction to
    patient could be achieved.
  13. Norpaiza Mohamad Hasan, Noraini Haron, Mohamad, Glam Hadzir Patai, Ismail Mustapha, Syed Yusainee Syed Yahya
    MyJurnal
    Paper recycling plants usually buy their raw material from suppliers. More than often, bulk used paper supplied to the plant contains some significant quantity of water in its internal voids. It may be included intentionally or unintentionally. The price of used paper depends on its weight, thus adding water will help to increase weight and consequently increase the price. In this way, plant owner who purchase the used paper suffers a significant of financial lost. The objectives of our experiment are to establish a calibration curve that correlate between the amount of neutron backscattered and water content, and finally to develop a correction factor that need to be introduced to the measured values of water content. A fast neutron source (Am-Be 241) and a portable backscattering neutron detector were used for water measurement. The experiments were carried out by measuring neutron backscattering from used paper that has been added with different amount of water. As a result, a neutron calibration curve that provides a correlation between neutron backscattering and water content was established.
  14. Muhammad Fakhrurazi Ahmad Fadzil, Siti Selina Abdul Hamid, Siti Najila Mohd Janib, Azahari Kasbollah, Syed Asraf Fahlawi Wafa
    MyJurnal
    Medical radioisotope is a small quantity of radioactive substance used for the purpose of diagnostic and therapy of various diseases. In Malaysia, the emerging of new nuclear medicine centers or institutions in both government and private sectors rose abruptly for the past few years. Currently, there are no data available on the usage and demand of these medical radioisotope or radiopharmaceuticals. The aim of this study is to assess current medical radioisotopes and radiopharmaceuticals usage and also to provide data on current medical radioisotope and radiopharmaceuticals demand for both private and government hospitals or institutions in Malaysia. A survey for a period of 3 months was conducted across Malaysia. The survey was divided into five (5) main parts and it was distributed among healthcare professionalsinvolved working with medical radioisotope and radiopharmaceuticals in private, government and university based hospitals or institutions and was distributed manually either by hand, mail ore-mail.Data is presented in either pie chart or bar chart. Survey results found out that the highest demand and the highest usage among all radioisotopes are Technetium-99m and radioiodine isotopes such as the iodine-131, iodine-131 MIBG, iodine-123 and iodine-123 MIBG. Technetium-99m is the backbone of nuclear medicine whereby more than 80% of Nuclear Medicine services utilize this radioisotope. Technetium-99m supply chain is unstable globally and in coming future, two main reactors that produce 60% of world Molybdenum-99 will shut down and the supply of molybdenum-99 will be disrupted. In radioiodine services, currently, Iodine-123 can’t be obtained in Malaysia and neighboring countries due to its short half-life. Iodine-123 is useful in diagnostic of thyroid related diseases. As for PET services, the highest demands are F-18 FDG and gallium-68 Generator. It is important for Malaysia to self-produced medical radioisotope and radiopharmaceuticals to meet the local market demand.
  15. Selambakkan, Sarala, Khomsaton Abu Bakar, Jamaliah Shariff, Suhairi Alimon
    MyJurnal
    This paper studies about water obtained from fish pond of fisheries research centre. Usual water
    quality parameters such as pH, COD, Turbidity and Ammonia content were analyzed before and
    after irradiation. Electron beam irradiation was used to irradiate the water with the dose 100 kGy,
    200 kGy and 300 kGy. Only high dose was applied on this water as only a limited amount of
    samples was supplied. All the parameters indicated a slight increase after irradiation except for the
    ammonia content, which showed a gradual decrease as irradiation dose increases. Sample
    condition was changed before irradiation in order to obtain more effective results in the following
    batch. The water sample from fisheries was diluted with distilled water to the ratio of 1:1.This was
    followed with irradiation at 100 kGy, 200 kGy and 300 kGy. The results still showed an increase in
    all parameters after irradiation except for ammonia content. For the following irradiation batch,
    the pH of the sample was adjusted to pH 4 and pH 8 before irradiation. For this sample the
    irradiation dose selected was only 100 kGy. A higher value of ammonia was observed for the
    sample with pH 4 after irradiation. Other parameters were almost the same as the first two batches
  16. Norazlina Noordin, Rusli Ibrahim, Nur Hidayah Mohd Sajahan, Salmah Moosa, Sobri Hussein
    MyJurnal
    Stevia rebaudiana Bertoni is a perennial herb that belongs to the family of Asteraceae. It is a
    natural sweetener plant known as sweet leaf, which is estimated to be 300 times sweeter than cane
    sugar. In this study, micropropagation and in vitro mutagenesis of this natural herb was
    successfully conducted. It was found that shoot tips on MS medium supplemented with 1 mg/l
    Kinetin showed the highest shoot induction and multiplication after 3 weeks of culture
    (5.50±1.95a). Radiosensitivity test was conducted to identify the dose that killed 50% of the
    irradiated explants (LD50) for in vitro stevia shoots and to select effective doses to be used for the in
    vitro mutagenesis. Shoot tips were irradiated with acute and chronic gamma radiation at 0, 10, 20,
    30, 40, 60, and 80Gy. At 60 Gy and 80 Gy, all treated shoot tips were not survived. In this study,
    LD50 for the stevia was estimated at 29 Gy for acute irradiation and 45 Gy for chronic irradiation.
    The effective doses were selected at 10, 20, 30 and 40 Gy. These selected doses were applied for the
    in vitro mutagenesis of the stevia shoots
  17. Norhayati Abdullah, Ng, Kwan Hoong, Wong, Jeannie Hsiu Ding, Ngie Min Ung, Taiman Kadni, Siti Sara Deraman
    MyJurnal
    The objective of this study is to perform a thermoluminescent dosimetry (TLD) postal dose quality audit for megavoltage X-ray teletherapy units in Malaysia. This audit is essential to be carried out to ensure adequate precision in the dosimetry of clinical beams before being delivered to the patients. Through this work, participating centres were requested to irradiate three capsules of TLD-100 powder with an absorbed dose to water of 2 Gy for 6MV and10MV photon beams. The International Atomic Energy Agency (IAEA)’s Technical Report Series No. 398 is used as a reference standard for TLD irradiation. Atotal of 22photon beamsfrom ten radiotherapy centres comprising onegovernment hospital and nineprivate medical centres were evaluated. The percentage deviation of user’s measured absorbed dose relative to Secondary Standard Dosimetry Laboratory (SSDL) mean absorbed dose was calculated. The results showed that all photon beams are within the IAEA’s acceptance limit of ± 5% except six photon beams. These centres were followed up with a second round of TLD irradiation which resulted in a better compliance.As a conclusion, regular audits should be performed to ensure consistency of radiotherapy treatment unit performances thus maintaining the accuracy of dose delivered to patients inall radiotherapy centres in Malaysia.
  18. Rosnani Abdul Rashid, Azhar Mohamad, Mat Rasol Awang, Hassan Hamdani Mutaat, Shaiful Azuar Mohamad, Affrida Abu Hasan, et al.
    MyJurnal
    Mushroom can be used as a biological indicator in assessing radiological impact on the
    environment. Radiological effect would be reflected through morphological changes as well as
    those changes at molecular level. For this purpose, a preliminary work was conducted, which
    included DNA isolation, optimization of PCR parameters for Inter-Simple Sequence Repeat (ISSR)
    and primers screening on Pleurotus sajor caju mushroom strains from Nuclear Malaysia’s
    Sterifeed Mushrooms Collection Centre. In this work, DNA isolation technique from cap and stalk
    of fruit body were optimized and quantified. It was found that stalk produced highest amount of
    genomic DNA at 304.01ng/µl and cap at 149.00ng/µl. A total of 100 ISSR primers were tested and
    51 primers were successfully amplified. These primers will be used further for dose response
    evaluation and molecular profiling in mushroom species.
  19. Aida Nazlyn Nazari, Azhar Mohamad, Shuhaimi Shamsudin
    MyJurnal
    Assessing performance and genetic diversity of the wild material of oil palm is important for
    under- standing genetic structure of natural oil palm populations towards improvement of the
    crops. This in-formation is important for oil palm breeding programs, and also for continued exsitu
    conservation of the germplasm and breeding program in Malaysia. Mutation induction is one
    of the approaches in creating variants for selection in the breeding program. In this study, the
    effect of irradiated pollen towards pollen viability, bunches formation and number of
    parthenocarpic fruits were evaluated. Elaies guineensis Jacq. pollens were exposed to series of
    acute gamma radiation at dose 0, 10, 20, 40, 50, 100, 200, 300, 500, 100 and 2000 Gy . Pollen
    viability and pollen tube formation were disrupted in which unable the pollen to reach the ovule.
    At this stage, embryo was aborted towards formation of parthenocarpic fruits and rotten bunches.
    The study suggested that at low levels of irradiation i.e. < 200 Gy, generative nucleus partially
    damage and it is still maintaining capacity of fertilizing the egg cells for hybridization. It is
    important for breeders in understanding this finding towards novel variants of oil palm via
    mutation induction
  20. Arwinder Singh, Lee Sing, Saw, Sor Heoh
    MyJurnal
    In this paper a study on the relationship between axial speed va, radial shock speed vs, piston speed
    vp and pinch temperature with the variation of pressure P0 was carried out. The Lee’s 5 phase
    model code was used in this study by configuring the India Bhabha Atomic Research Center
    (BARC) plasma focus machine to operate in the pressure (P0) range from 1 Torr to 14 Torr. The
    relationships between these parameters were obtained as follows:

    Va ≈ 9Po-0.37, Vs ≈ 45P0-0.48, Vp ≈ 30P0-0.47 and Tpinch(max) ≈ 11P0-1
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