Displaying publications 1 - 20 of 95 in total

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  1. Faiz Ahmad, Zaiton Ahmad, Affrida Abu Hassan, Sakinah Ariffin, Norazlina Noordin, Shakinah Salleh, et al.
    MyJurnal
    The research on radiation induced mutation has been conducted as one of the promising method of plant breeding in Malaysia since 1980s. Nuclear Malaysia is leading research institute inMalaysia conducting plant mutationbreeding research. Gamma Greenhousefacility located in Nuclear Malaysiais one of the irradiation facilitiesto serve as a chronic irradiation facility for inducing mutation in various organisms including plants, fungi and microbes.Chronic irradiation refers to the exposure of materials at a lower dose rate over a long period of time. Previous studies have shown that this type of irradiation can minimize radiation damages to living materials and produces a wider mutation spectrum, therefore is very useful for trait improvements in irradiated organisms. Experiments on induce mutation using Gamma Greenhouse facility for crop improvement program have been conducted since its first operation in 2009. Various plant species including ornamental and herbal plants, food crops and industrial crops have been irradiated to improve their traits such as higher yield and biomass, pest and disease tolerance, higher bioactive compounds, longer bloom time and many others. Most of these crop improvement programs were done through collaborations with other agencies in Malaysia such as universities, research institutes and government departments. A number of publications on crop improvement using Gamma Greenhouse have been published inlocal and international journals as well as seminar presentations at national and international levels. The outputs from induced mutation via chronic radiation using Gamma Greenhouse could be of great interest for plant breeders dealing with improvement and development of new cultivars. This paper discusses the activities and achievement in plant breeding and improvement using Gamma Greenhouse Facility in Malaysia.
  2. Shamsiah Abdul Rahman, Md Suhaimi Elias, Nazaratul Ashifa Abdullah Salim, Zalina Laili, Azian Hashim, Shakirah Abd Shukor, et al.
    MyJurnal
    Samples of fine (PM2.5) and coarse (PM10-2.5) fraction of airborne particulate were collected on weekly basis during the period from May 2012 to July 2014 at Bangi, Selangor. The samples were collected using a Gent Stacked Filter Sampler in two fractions of < 2.5 µm and 2.5 - 10 µm sizes. This research paper aims at establishing the concentration level of PM2.5, PM10-2.5 and PM10 at Bangi area and investigates their possible sources and contribution to the ambient aerosol of the area. The samples were analyzed for their elemental composition and black carbon content by Particle Induced X-ray Emission (PIXE) and Smoke Stain Reflectometer, respectively. The average for PM2.5, PM10-2.5 and PM10 ranged from1.8 µg/m3 to 78.0 µg/m3, 9.6 µg/m3 to 76.8 µg/m3 and 12 µg/m3 to 134 µg/m3, respectively. Positive Matrix Factorization (PMF) technique was also applied to fine and coarse data set in order to identify the possible sources of particulate matter (PM) and their contribution to the ambient particulate matter concentrations in the area. The best solution was found to be five factors for both elemental compositions of fine and coarse PM, respectively. The PMF results show that motor vehicles and secondary sulphate contribute about 40.3% and 33.0% of the fine mass respectively followed by soil, sea salt and smoke/biomass burning with the average contribution of 10.5%, 10.3% and 6.4%, respectively. In case of coarse particles the PMF results show that a large fraction of about more than 50% of the coarse mass comes from motor vehicle. Soil dust including road dust and soil construction contribute about 32.5% of the coarse mass whilst the smoke/biomass burning factor contributes about 6.7% of the coarse mass.
  3. 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.
  4. Norhayati Abdullah, Kadni, Taiman, Mohd Taufik Dolah
    MyJurnal
    In this paper, we report the dosimetry methodology used in the IAEA/WHO Thermoluminescent Dosimeter (TLD) Postal Dose Quality Audit Service and the results of 22 Malaysian radiotherapy centres participated in the audit from 2011 to 2015. Each participating centre was provided with a few sets of TLD capsule (two unit of TLD capsules to be irradiated and a control TLD in one set) as requested by the centres. The participating centres were asked to irradiate each TLD capsule at 2 Gy absorbed a dose to water under reference conditions i.e the TLD capsule is positioned at 10 cm depths in water, at central axis with 10 cm x 10 cm field size at 100 cm Source-Surface Distance or 100 cm Source-Axis Distance. In this period, a total of 70 photon beams consist of 43 beams and 27 beams produced by 6 MV and 10 MV photon beams, respectively have been audited. The results demonstrated that all participating centres comply with the acceptance limits of ± 5% as recommended by the International Commission on Radiation Units and Measurements (ICRU) Report 24, except eight photon beams from six centres. However, these centres presented better compliance results after being followed up with a second round of TLD irradiation.

  5. Ismail Sulaiman, Khairuddin Mohamad Kontol, Faizal Azrin Abdul Razalim
    MyJurnal
    The indoor and outdoor radon concentrations in Cameron Highlands (Peninsular Malaysia) and Ranau (East Malaysia) were measured. The measurements were carried out using passive method based on CR-39 solid state nuclear track detector (SSNTD) (for indoor measurements in Cameron Highlands) and active method using continuous radon/thoron progeny monitor (for indoor and outdoor measurements in Ranau and outdoor measurements in Cameron Highlands). The mean indoor radon concentrations in Cameron Highlands and Ranau were 50 Bqm-3 and 1.5 Bqm-3, respectively. The mean indoor radon concentration in Cameron Highlands was slightly higher compare to the world average. The maximum value recorded was 97 Bqm-3 which is almost similar to WHO reference level. The mean outdoor radon concentrations in Cameron Highlands and Ranau were 7.4 Bqm-3and 1.7 Bqm-3, respectively. The outdoor concentrations were low and comparable to world outdoor average.
  6. Mohd Fahmi Mohd Yusof, Puteri Nor Khatijah Abd Hamid, Abdul Aziz Tajuddin, Rokiah Hashim, Norriza Mohd Isa
    MyJurnal
    The mass attenuation coefficients of solid water phantoms, Perspex® phantoms and Rhizophora spp. particleboards were determined by using Compton scattering technique measured using Ludlum configuration. The gamma energy of 137Cs sealed source were measured at 30°, 45°, 60° and 75° angles providing scattered gamma energies between 337.72 and 564.09 keV. The mass attenuation coefficients of solid water and fabricated Rhizophora spp. particleboards were the nearest to XCOM values of water with average percentage of discrepancies of 6.8% and 5.9%, respectively. The results indicated similar attenuation properties of solid water and fabricated Rhizophora spp. particleboards and the suitability of the Ludlum configuration to determine the mass attenuation coefficient of materials using Compton scatter technique.
  7. Raizulnasuha Ab Rashid, Nurul Afifah Aziz, Ili Zawani Khairuddin, Wan Nordiana Wan Abdul Rahman, Norhayati Dollah
    MyJurnal
    Radiobiological model such as linear quadratic (LQ) is widely used in radiotherapy to predict the biophysical response of the tumour cell to the radiation. In clinical radiotherapy, LQ model is widely employed to plan treatment delivery and fractionation. Nevertheless, LQ model might not provide accurate prediction for high dose rate treatment. This study investigates the radiation cell survival responses using LQ model and alternative Multi-Target (MT) model. The experimental works were conducted in-vitro using HeLa cells that were irradiated using photon and electron beams of different energy. Cells irradiation were performed in full scatter condition and exposed to radiation doses ranges from 1 to 10 Gy. Clonogenic assay is used as an endpoint to obtain the cell survival curves which later be fitted with LQ and MT model. The results demonstrate that MT model produce the fitting curves that are closed to the experimental data compare to LQ model especially at high doses. Parameter analysis from both models indicates more biological damage inflicted by high energy electron beam. Correlation between the experimental cell survival data and radiobiological model analysis suggesting that alternative radiobiological model such as MT model could be applied in analysing cells’ radiation survival and damage in clinical radiotherapy.
  8. Wan Nordiana W Abd Rahman, Raizulnasuha Ab Rashid, Mahfuzah Muhammad, Khairunisak Abdul Razak, Norhayati Dollah, Moshi Geso
    MyJurnal
    Gold nanoparticles (AuNPs) have been extensively investigated as dose enhancement agent to increase the lethal dose to the tumours while minimizing dose to the normal tissue. Their intriguing properties and characteristics such as small size and shape provide favorable option in increasing radiotherapy therapeutic efficiency. In this study, the effects of AuNPs size on the dose enhancement effects irradiated under megavoltage photon beams were investigated. The study was conducted in-vitro on HeLa cells using AuNPs of 5 nm and 15 nm sizes. The cells samples were incubated with AuNPs and irradiated with photon beam of energy 6 MV and 10 MV at 100 cm SSD and 10 cm x 10 cm field size. Clonogenic assay were performed to observe the dose enhancement effects on cell survival. Dose enhancement factor (DEF) were extrapolated and evaluated from the cell survival curves. The results show that both sizes of AuNPs produce dose enhancement with the larger size AuNPs of 15 nm produce more dose enhancement compare to 5 nm AuNPs for 6 MV photon beam. Dose enhancements were observed for 10 MV photon beams but DEF for both sizes AuNPs shows no differences. In conclusion, larger size AuNPs produce higher dose enhancement compare to small size of AuNPs which conclude that nanoparticles size is important factor that need to be taken into account for AuNPs to be applied in radiotherapy.
  9. Rosmazihana Mat Lazim, Raizulnasuha Ab Rashid, Wan Nordiana Rahman, Binh. T.T. Pham, Brian S. Hawkett, Moshi Geso
    MyJurnal
    Therapeutic application of metallic nanoparticles such as gold nanoparticles have been extensively investigated and intriguing finding have been reported. Superparamagnetic iron oxide nanoparticles (SPION) could also potentially have therapeutic properties that can be exploited to enhance radiotherapy outcome. In this study, investigations on the dose enhancement effects inflicted by SPIONs under irradiation with megavoltage photon beam radiotherapy were conducted. T24 human bladder cancer cell lines were pretreated with 1 mMol/L of SPION and irradiated with 6 MV and 10 MV photon beam at different doses.The non-treated cells irradiation was used as a control. Clonogenic assay was performed to determine the cell survival. Linear quadratic (LQ) model are used as fitting curve and does enhancement factors (DEF) were extrapolated from the curves. The cytotoxicity indicated cell growth normally after 72 hours and no long term cytotoxicity effects of SPIONs towards the cells were observed. The dose enhancement effects were observed for both 6 MV and 10 MV photon beam with DEF obtained 1.71 and 2.50, respectively. This reduction of cell colonies growth could be resulted from the interaction that induced free radical and reactive oxygen species (ROS) by megavoltage photon beams. The SPIONs were therefore act as multifunction nanoparticle both in diagnostic agent and radiotherapy as radiation dose enhancer, thus clearly qualified as future theranostic agents.
  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. Fadzil, M.S.A., Mohd Noor, N., Tamchek, N., Ung, N.M., Alawiah, A., Abdullah, N., et al.
    MyJurnal
    The thermoluminescence kinetic parameters of Ge-doped flat fibre have been investigated comprehensively using the computerized glow curve deconvolution analysis. The Ge-doped flat fibre was irradiated to 6 MV and 10 MV photon beam with dose ranging from 100 cGy to 300 cGy. Analysis was done using WinGCF software on the dependence of the glow curve intensity on dose delivered and the determination of the trap parameters. Ge-doped flat fibre was found to be linear over the entire dose range explored for both 6 MV and 10 MV irradiations with r2 value of 0.9955 and 0.9933 respectively. The glow curve consists of five individual glow peaks. The peak height increases with increasing irradiation dose. The first peak (P1) is a dominant individual peak for low temperature peak (LTP) with the maximum temperature ranging from 167.4°C to 179.0°C for both beams studied. Meanwhile, peak (P4) is a dominant individual glow curve for high temperature peak (HTP) with maximum temperature for 6 MV and 10 MV and is observed between 264.5°C to 279.4°C. Peak 1 has the lowest activation energy which is less than 0.72 eV while peak 2 shows the highest activation energy (1.3 eV < Ea < 2.1 eV) which indicates the deepest electrons trap. The results showed that the peak integral will increases as the dose increases. The Ge-doped flat fibre demonstrated the second-order kinetic peak behavior by exhibiting the symmetric shape of the glow curve with high temperature half of the curve slightly broader than the low temperature half, which suggests the possibility of electron retrapping.
  12. Sofian Ibrahim, Chantara Thevy Ratnam, Chai, Chee Keong, Noor Hasni M. Ali, Mohd Noorwadi Mat Lazim, Khairiah Badri
    MyJurnal
    Peroxide pre-vulcanized natural rubber latex prepared by using gamma irradiation technique is an alternative over the conventionally prepared peroxide pre-vulcanized that used activator to promote the peroxide decomposition in natural rubber latex. Through this technique the problems aroused by some activators such as tends to darken the natural rubber latex film during the drying process can also be overcome. For this preliminary study, data obtained from crosslink density and mechanical measurements were used to evaluate the effectiveness of gamma irradiation in the vulcanization process. Increasing the quantity of tert-butyl hydroperoxide (t-BHPO) from 0.1 pphr to 0.3 pphr while the irradiation dose maintain at 12 kGy has successfully delivered peroxide vulcanized natural rubber latex films with average tensile strength, modulus @ 500% and modulus @ 700% around 15.33, 1.01 and 3.42 MPa, respectively. The effective pre-vulcanization irradiation dose with respect to maximum crosslinking density (85.8 %) was observed on film prepared at 0.1 pphr t-BHPO.
  13. Mohd Zulmadi Sani, Faiz Ahmad, Mustapha Akil, Zaiton Ahmad, Affrida Abu Hassan, Abdul Rahim Harun, et al.
    MyJurnal
    Kenaf (Hibiscus cannabinus L.) is one of the world’s most economically important fiber crops particularly in Asia-Pacific region. Mutation induction is a method to increase genetic divergence associated with selection, recombination, or a combination of these approaches in plant breeding. One of preliminary procedures for an execellent mutation breeding program is the radiosensitivity study to determine the optimal doses for irradiation. A total of 10 different doses of acute gamma rays (0, 100, 200, 400, 800, 1000, 1200, 1500, 1700 and 2000 Gy) from ceasium-137 source were applied to the seeds of V 36 kenaf variety. The irradiated seeds including the control were planted in trough for 30 days. The gamma irradiation effects on several parameters such as seedling survival percentages, plant height, root length, shoot fresh weight, root frest weight, shoot dry weight and root dry weight were analysed. From the radiosensitivity curve, the LD50 and LD25 values were estimated at 810 and 310 Gy, respectively. Two doses (200 Gy and 300 Gy) based on LD25 were chosen for evaluating the effects of gamma irradiation on morphological traits in M1 generation. Irradiated and non-irradiated seeds were planted in the field at Beseri, Perlis. About 10 phenotypic traits of irradiated plants were observed and evaluated against the controls. Cluster analysis on M1 progenies showed that the mutation could be classified into eight genotypic groups. The first two components from principal component analysis explained about 77.99% of variation. Number of seeds per pod, weight of seeds per plant and dry stem biomass play an important role in explaining the variation since they showed positive correlated values for the first component analysis. Morphological changes such as flower shape, flower colour, and leaf shape were also observed in M1 generation. The findings of this study are important in determining the effectiveness of these doses in generating mutations on kenaf plant and subsequent breeding program to develop new kenaf varieties with enhanced quality traits.
  14. Mohamad Hairie Rabir, Julia Abdul Karim, Muhammad Rawi Mohamed Zin
    MyJurnal
    The Malaysian’s PUSPATI TRIGA Reactor (RTP) achieved its initial criticality on June 28, 1982. The reactor is designed to effectively implement various fields of basic nuclear research, manpower training, and production of radioisotopes. Several past activities on neutronics modelling development and validation of the RTP were carried out using Monte Carlo Code MCNP. In this work, the developed model was used to characterise in-core and beam-ports irradiation facilities of the reactor. The thermal and fast neutron flux distributions in these facilities were determined using MCNP mesh tally method. It was found that the flux as well as its spectral characteristics depended very much on the position of the irradiation facility in the reactor core or in the beam-ports. The maximum neutron flux was found to be in the Central Thimble facility with 1.98E13 nv of thermal neutron. The thermal-to-total flux ratio varies significantly from 0.41 for the in-core facility, 0.58 in the reflector and up to 0.88 in the beam-ports.
  15. Zal U'yun Wan Mahmood, Norfaizal Mohamad, Nur Nazirah Johari
    MyJurnal
    Accumulation kinetic trends of cesium and cadmium in the Penaeus monodon were studied using Cs-134 and Cd-109 as a tracer. The objective of this study was to quantify the uptake and loss/depuration kinetic of these two radionuclides in the Penaeus monodon. Uptake and loss/depuration kinetic of these two radionuclides in the Penaeus monodon were varied widely, displayed a simple double kinetic model of linear and exponential trend with time unless modified by moulting at the stage in the mount cycle. Therefore, the variation of Cs-134 and Cd-109 bio-concentration factor could be concluded considerably influence by moulting cycle, environmental and biological condition as well as physico-chemical that direct effects on their uptake and loss/depuration kinetic.
  16. Puteri Nor Khatijah Abd Hamid, Abdul Aziz Tajuddin, Mohd Fahmi Mohd Yusof, Rokiah Hashim
    MyJurnal
    The particleboards were fabricated using Rhizophora spp. wood particles with particles size less than 74 μm. The corn starch was used as a bio-adhesive in the fabrication of Rhizophora spp. particleboards. The corn starch bonded particleboards were fabricated at 5% and 10% corn starch based on dry mass of Rhizophora spp. wood particles. The measurement of mass attenuation coefficients of the particleboards were made at low and intermediate photon energies. The mass attenuation coefficient at low photon energy was measured using X-ray fluorescent (XRF) configuration based on attenuation of Kα1 X-ray energies between 16.59 and 25.26 keV given by niobium, molybdenum, palladium and tin metal plates. The calculated mass attenuation coefficients of samples were compared to the theoretical values mass attenuation coefficients of water calculated using the photon cross-section database (XCOM). The results showed that mass attenuation coefficients of 10% corn starch added Rhizophora spp. particleboards were in good agreement of water within 7.96 and 4.94% for 5% and 10% corn starch Rhizophora spp. Particleboards, respectively compared to 14.57 and 16.16% in binderless Rhizophora spp. particleboards and raw Rhizophora spp. wood, respectively.
  17. 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.
  18. Ismail Sulaiman, Khairuddin Mohamad Kontol, Faizal Azrin Abdul Razalim, Azman Jaafar
    MyJurnal
    The objective of this study was to measure indoor radon concentrations in the expected high risk area around Ipoh in Kinta Valley, Perak. The area was chosen based on its own special characteristics. The measurements were carried out by means of long term exposure (3 months) using CR-39 solid state nuclear track detector. The mean indoor radon concentration in Ipoh was 45 Bq/m3 which is equivalent to effective dose of 1.1 mSv/y. This value was higher compared to low or normal area in Bangi, Selangor but comparable to the world average value reported by UNSCEAR. The maximum value of indoor radon concentration measured was 87 Bq/m3.
  19. 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
  20. Mohd Fahmi Mohd Yusof, Nur Amirah Nabila Ramli, Mohd Fahrizuan Md Yusop, Reduan Abdullah
    MyJurnal
    This study evaluates the ImageJ software as dosimetric tools for analyzing the film dosimeter in high energy photons and electrons. The percentage depth dose of photons of 6 and 10 MV and electrons of 6 and 9 MeV were measured using the Gafchromic EBT2 film dosimeter. The films were scanned and analyzed using the Verisoft software and ImageJ. The beam profiles at nominal photon and electron beam parameters were also evaluated using the two methods. The PDD measured in ImageJ at high energy photons were in good agreement within 1% percentage of discrepancy at all depths in comparison to the Verisoft software. The PDD measured in ImageJ at high energy electrons also showed good agreement to Verisoft software within 8% percentage of discrepancy at all depths. The measured flatness of beam profiles at Dmax, R50, R80 and R90 in ImageJ were also in good agreement to Verisoft software with flatness value between 4 and 8%. The results indicated the suitability of ImageJ software as dosimetric tool for analyzing EBT2 film dosimeter at high energy photon and electrons.
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