The exposure of food to ionizing radiation is being progressively used in many countries to
inactivate food pathogens, to eradicate pests and to extend shelf-life of food. To ensure free
consumer choice, irradiated food will be labeled. The availability of a reliable method to detect
irradiated food is important to enforce legal controls on labeling requirements, ensure proper
distribution and increase consumer confidence. This paper reports on the preliminary application
of photostimulated luminescence technique (PSL) as a potential method to detect irradiated food
and perhaps be used for monitoring irradiated food on sale locally in the near future. Thus this
study will be beneficial and relevant for application of food irradiation towards improving food
safety and security in Malaysia.
Heel Effect is the well known phenomena in x-ray production. It contributes the effect to image
formation and as well as scattered radiation. But there is paucity in the study related to heel effect.
This study is for mapping and profiling the dose on the surface of water phantom by using mobile
C-arm unit Toshiba SXT-1000A. Based on the result the dose profile is increasing up to at least
about 57% from anode to cathode bound of the irradiated area. This result and information can be
used as a guide to manipulate this phenomenon for better image quality and radiation safety for
this specific and dedicated fluoroscopy unit.
Carbon-11 labeled radiotracers, such as 11C-acetate and
11C-palmitate are widely used in positron
emission tomography (PET) for noninvasive evaluation of myocardial metabolism under varied
physiological conditions.These tracers are attractive probes of tissue physiology, because they are
simply radiolabled versions of the native biochemical substrates. One of the major metabolites
generated by these tracers upon the administration is 11CO2 produced via the citric acid cycle. In
quantitative modeling of
11C-acetate and
11C-palmitate PET data, the fraction of blood
11C
radioactivity present as
11CO2 needs to be measured to obtain a correct radiotracer arterial
input function. Accordingly, the literature describes a method whereby the total blood
11C-activity
is counted in blood samples treated with base solution, while the fraction of
1 1CO2 is measured
after the blood is treated with acid followed by a 10 minutes gas-purge. However, a detailed
description of the experimental validation of this method was not provided. The goal of this study
was to test the reliability of a 10 minute gas purging method used to assay
11CO2 radioactivity in
blood
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
Haruan or Channa striatus is source of protein that is widely consumed in the region and its extract
is well known for having medical values. It is of great advantage if this product could be taken
orally rather than by injection because the oral route of drug delivery is still preferred by the vast
majority of patients. However protein and peptides can be denatured or degraded by the acidic pH
of the stomach and the presence of endogenous enzymes. In order to protect or prevent digestion
and degradation of the protein in the stomach and to ensure the protein reaches the gastro
intestinal (GI) tract, Carboxymethyl Starch (CMS) nanogel system was developed using electron
irradiation method. However stability of HTE during the irradiation process needed to be studied
before being developed further. In this study, the HTE was irradiated using electron beams. Its
stability was analysed in terms of physical and chemical changes by looking at colour difference,
melting point by using Differential Scanning Calorimetry (DSC) and molecular bonds by using
Fourier Transform Infrared (FTIR) respectively. The results of this study were that no apparent
colour difference was observed with HTE before and after irradiation. These observations were
supported by the FTIR and DSC results that showed that there were no changes in molecular bonds
and melting point, compared between no irradiation and irradiation HTE during electron
irradiation up to 10 kGy. Statistically the test showed no significant difference at p < 0.005 between
melting temperatures.
Anthropogenic airborne depositions of 210Po,
210Pb and 210Po/210Pb in the mosses and surface soils
collected at the vicinity of a coal-fired power plant were studied. The purpose of the study was to
determine activity concentrations of 210Po,
210Pb and 210Po/210Pb for assessing their variation
accumulation in the mosses and surface soils collected at the vicinity of a coal-fired power plant.
Other purposes were to determine their concentration factor (CF) in relation to track the potential
source of those radionuclides and to identify most suitable moss species as a biological indicator
for atmospheric deposition contaminants. In this study, different species of moss Leucobryum
aduncum, Campylopus serratus, Syrrhopodon ciliates and Vesicularia montagnei were collected in
May 2011 at the area around 15 km radius from Tanjung Bin coal-fired power plant located in
Pontian, Johor. The activity concentrations of 210Po,
210Pb and 210Po/210Pb in mosses were in the
range of 76.81 ± 4.94 – 251.33 ± 16.33 Bq/kg dry wt., 54.37 ± 3.38 – 164.63 ± 11.64 Bq/kg dry wt.
and 1.10 – 2.00, respectively. Meanwhile the ranges for those radionuclides in the surface soil
were 33.53 ± 2.10 – 179.67 ± 12.15 Bq/kg dry wt., 20.55 ± 1.33 – 106.62 ± 6.64 Bq/kg dry wt. and
1.61 – 2.44, respectively. Corresponding high ability of Leucobryum aduncum to accumulate more
210Po and 210Pb, wide geographical distribution, most abundant and high CF, therefore, the
findings can be concluded this species was the most suitable as a biological indicator for
atmospheric deposition contaminants such as 210Po and 210Pb. Furthermore, it is clear the
accumulation of 210Po and 210Pb in mosses might be supplied from various sources of atmospheric
deposition such as coal-fired power plant operation, industrial, agriculture and fertilizer activities,
burned fuel fossil and forest; and other potential sources. Meanwhile, the
Radiation processing of food materials by gamma-radiation is a well-established method for
microbial decontamination and insect disinfestation. Irradiation of spices at doses ranging from
10 to 30 kGy has been reported to result in complete elimination of microorganisms with
negligible changes in the flavour quality. The effect of gamma-radiation on microflora and
vanillin content of cured vanilla beans in the dose range of 5 - 50 kGy has been investigated, but
its effect on other major aroma compounds and vanillin glucoside (vanillin aroma precursor)
remaining after curing have not been studied so far. Vanillin (4-hydroxy-3-methoxybenzaldehyde)
is one such compound used as a flavouring agent and as a dietary component. It is the major
component of natural vanilla, which is one of the most widely used and important flavouring
materials throughout the world. Vanillin is an antioxidant capable of protecting membrane
against lipid peroxidation and DNA against strand breaks induced by reactive oxygen species.
The present work was aimed to study the effect of gamma-radiation processing on the major
aroma compounds of cured vanilla beans and also to investigate possible enhancement in vanillin
content by the radiolytic breakdown of vanillin glucoside present already. Cured vanilla beans
were irradiated (5, 10, 15, 20 and 30 kGy) and the vanillin content of control and irradiated
samples were analysed, respectively for possible enhancement of vanillin content by radiolysis of
vanillin glucoside. Radiolytic breakdown of glycosidic precursors of aroma constituents and
consequent release of free aroma was shown to result in the enhancement of aroma quality of
these products. Since a considerable amount of vanillin exists as its glycosidic precursor in cured
vanilla pods, a possible enhancement in yield of vanillin by radiation processing is thus expected.
Hence the highly stable oxygen–carbon linkage between vanillin and glucose limits the possible
enhancement of aroma quality of irradiated beans.
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.
Nur Humaira’ Lau Abdullah, Zal U’yun Wan Mahmood, Norfaizal Mohamed @ Muhamad, Nazaratul Ashifa Abdullah Salim, Ahmad Nazrul Abd Wahid, Nor Dalila Desa, et al.
A glasshouse experiment was performed to evaluate the uptake of grasses viz. Napier and Vetiver
in radiophytoremediation of caesium-contaminated soil. The radiophytoremediation experiment
was designed according to the Randomized Complete Block Design (RCBD). The grasses were
grown in troughs filled with soil mixed with a known specific activity of 134Cs. Initial Cs activity and
activity after different cultivation time intervals of 1, 3, 6 and 9 months were analyzed using gamma
spectrometer direct measurement. The results showed the uptake of caesium by Napier and Vetiver
after 9 months with the transfer factors (TF) were 4.70 and 6.25, respectively. The remediation of
caesium from the contaminated soil during the study period was 98.08% for Napier and 98.21% for
Vetiver. Both grasses have been found to accumulate caesium, with Vetiver accumulating higher
than Napier. Thus, the present study suggests that Vetiver could be used as a potential plant for
radiophytoremediation of caesium.
The remote measurements of radiation level at an identified location, are not only important for
collecting data or monitoring radiation level per se, but also crucial for workers who deal with
radiation sources. A device for checking an on-site radiation level has been developed quite a
long time ago under the name of Geiger Muller and widely known as a Geiger counter. The
reading of the output can be seen on the device on-site and on real-time basis. Nowadays, with
the fast evolution of computer and networking technology, those reading not only can be read
real-time but also from a remote location that makes workers able to enter the risky area more
safely. The collected data reading also can be analyzed for predicting the future trending
pattern. The data is transferred from the monitoring devices to a server through a network. This
paper discusses about several critical issues on the design, implementation and deployment that
relates to the devices, interface programs, hardware and software that allow all parameters such
as radiation levels reading and the timestamp of the data-logging can be collected and stored in
a central storage for further processes. The compatibility issue with regards to technology
change from the previous system will also be discussed. The system has many advantages
compared to previous system and conventional method of doing the area monitoring in term of
sustainability and availability.
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
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.
“Batu Bersurat Terengganu (inscribed stone)” is the oldest artifact with Jawi writing on it. The
artifact proves that the Kingdom of Terengganu exist earlier than 1326 or 1386. To date, a lot of
studies on the content of the inscription have been carried out by historians and archaeologists, but
no scientific investigation about the material composition and its provenance has been performed.
This paper focuses on the study of the origin of the Batu Bersurat Terengganu using NeutronInduced
Prompt Gamma-Ray Techniques (NIPGAT). Portable NIPGAT system has been designed
and developed based on volumetric measurement methods and it will be considered as a nondestructive
testing. The system uses low activity of californium-252 (Cf-252) neutron radioactive
sources, gamma ray spectroscopy and special computer software to carry out the investigation. The
study found that the Batu Bersurat Terengganu is made of dolerite based on the elemental
composition of the stone. Although most of the scientific data for the study of the origin are already
obtained, but further research is still ongoing to complete the scope of this study.
This paper aims at presenting preliminary results of a survey on physical factors, namely tube
potential (kV), tube current exposure time product (mAs) and compressed breast thickness (CBT)
during voluntary mammography screening using Full-Field Digital Mammography (FFDM) System
in Malaysia. Retrospective data were collected from 1128 FFDM images of 282 women from three
major ethnic groups (Malay, Chinese and Indian) who underwent voluntary screening
mammography at Breast Centre, International Islamic University Malaysia from January to March
2008. Results from the present study were then compared with results from the previous study on
Screen-Film Mammography System (SFM) according to the ethnic group for both Cranio-caudal
(CC) and Mediol-Lateral (MLO) views. We found that the mean kV for CC view for the three ethnic
groups are Malay (28), Chinese (28) and Indian (28), and for MLO view are Malay (29), Chinese
(28) and Indian (29). These values are higher than the kV for SFM which were Malay (26), Chinese
(27) and Indian (26) for CC and Malay (26), Chinese (27) and Indian (26) for CC and MLO views
respectively. The mean mAs for CC and MLO views for FFDM were lower compared to SFM
systems. These values were Malay (104), Chinese (108) and Indian (91) for CC views and Malay
(106), Chinese (105), and Indian (94) for MLO views for the FFDM system. The values for SFM
system are for CC and MLO views were Malay (120), Chinese (106) and Indian (126), and Malay
(166), Chinese (132), Indian (183) respectively. The median CBT for CC and MLO views increased
by 27% and 7% respectively on the FFDM compared to the SFM system. In conclusion, the FFDM
operates with higher kV, lower mAs, and higher CBT when compared with SFM system. Median
CBT on CC and MLO view with FFDM system are 27% and 7% higher respectively compared to
the SFM. We are currently collecting data on mean glandular dose with FFDM systems to assess
how the change in local mammography practice influences this value. This will allow comparison
with related data from other parts of the world.
The acrylated palm oil (APO) nanoparticle is a potential product that can be used as carriers in
medical field. The main focus of the present study was to study the potential of the APO
nanoparticles for used in a controlled drug delivery system. The microemulsion system is used as a
medium to incorporate an active substance such as Thymoquinone (TQ) into the APO polymeric
micelle and then the radiation technique is used as a tool for the synthesis of TQ-loaded APO
nanoparticle. The nano-size TQ-loaded APO particles resulted the particle size of less than 150 nm
with spherical in shape. The TQ release profile was carried out in potassium buffer saline (PBS)
solutions (pH 7.4) at 37
oC. And, the zero-order model has been used to determine the mechanism
of the drug release from the corresponding nanoparticles, respectively. The TQ release was found
to be sustained and controlled in pH 7.4. At pH 7.4, the release of TQ followed the zero-order
model. The in-vitro drug release study showed a good prospect of the APO nanoparticle on being a
potential drug carrier as there are toxic against colon cancer cells and not toxic towards normal
cells. This suggested that the APO product produce using this radiation technique can be
developed into different type of carrier systems for controlled drug release applications.
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.
An improved laboratory technique for measurement of polonium-210(
210Po) in environmental
samples has been developed in Radiochemistry and Environmental Laboratory (RAS), Malaysian
Nuclear Agency. To further improve this technique, a study with the objectives to determine the
optimum conditions for
210Po deposition and; evaluate the accuracy and precision results for
the determination of 2 1 0 P o in environmental samples was carried-out. Polonium-210 which
is an alpha emitter obtained in acidic solution through total digestion and dissolution of samples
has been efficiently plated onto one side of the silver disc in the spontaneous plating process for
measurement of its alpha activity. The optimum conditions for deposition of 210Po were achieved
using hydrochloric acid (HCl) media at acidity of 0.5 M with the presence of 1.0 gram hydroxyl
ammonium chloride and the plating temperature at 90
oC. The plating was carried out in 80 mL
HCl solution (0.5 M) for 4 hours. The recorded recoveries obtained using 2 0 9 P o tracers in
the CRM IAEA-385 and environmental samples were 85% – 98% whereby the efficiency of the
new technique is a distinct advantage over the existing techniques. Therefore, optimization of
deposition parameters is a prime importance to achieve accuracy and precision results as well as
economy and time saving
A study has been carried out using a gamma-ray spectrometric system to determine the natural
radioactivity level in bricks made from industrial waste and their associated radiation hazard.
Brick-1 and brick-2 contained waste from coal power plant and granite industry, respectively. The
leachability of radionuclides from these bricks was also investigated. The activity concentration
values of 226Ra,
228Ra,
232Th, and 40K are 64.25, 63.15, 67.9 and 254.19 Bq/kg, respectively in brick-
1, and 193, 164.48, 164.63 and 1348.75 Bq/kg, respectively in brick-2. The radiation hazard
indexes such as radium equivalent activities (Raeq), representative level index (Iγr), external hazard
index (Hex) and internal hazard index (Hin) were calculated and compared with the internationally
approved values. Results indicate that brick-1 showed less radiological hazard than brick-2. This
suggested that brick-1 could be used in building construction without exceeding the proposed
criterion level.The leachability of 226Ra for bricks showed the activity concentration slightly
exceeded 1 Bq/L which is the limit generally used for industrial wastewater.
Effects of 3 MeV electron (10 mA) irradiation at room temperature on the phase, microstructure,
electrical and life time properties of 4H-SiC wafer were investigated by scanning electron
microscopy (SEM), X-ray diffraction (XRD), four point probe current-voltage measurements and
positron annihilation spectroscopy. It was found that irradiation damage in SiC wafer is
significantly increased with the increase of radiation dose as observed in SEM. Irradiation also
resulted in modification of crystallite size as identified by XRD. The resistance of a sample before
irradiation was found to be 0.8 MΩ, whereas for a sample irradiated at 200 kGy, the resistance as
measured by four point probe was 5.2 MΩ. It seems that the increase of resistance hence, reduction
in conductivities could be due to defects induced by the radiation dose received then created
leakage currents at both reverse and low-forward biases and creation of traps in the SiC.
Meanwhile positron annihilation spectroscopy (PAS) was used to analyse the life time of irradiated
samples which nonetheless shows that all irradiated sample have similar life time of 151 ps. It was
observed that that no degradation process of materials experienced by SiC wafer irradiated at 500
kGy.
Development of biofertilizer seed treatments for okra seeds were carried out by mixing phosphate
solubilising bacteria (AP 3) and plant growth promoter (AP 2) with adhesives. The seeds were
coated with inoculums and four types of adhesives namely, Gum Arabic; Polyethylene Glycol
(PEG); Sodium Alginate and Methycellulose respectively. From eight seed treatments, all seed
treatments significantly increased seed germinations except treatment T4 (Gum Arabic and AP3).
In general, maximum germination rates and log of viable cells were observed when treated with
polyethylene glycol 4000 (PEG) mixed with AP2 (T7) and AP3 (T8). These results show that using
PEG as adhesive enhanced the germination rates and log of viable cells of AP2 and AP3. Thus,
PEG could be a good adhesive for seed treatment. In greenhouse experiment, okra seeds treatment
with AP2 and PEG (T1) showed the highest dry weight compared to other treatments. Seeds
treatment with AP3 and PEG (T2) showed higher contribution of N compare to seeds treatment
(T1). There were no significant different within seed treatments and urea treatment in okra yield.
All treatments significantly increased yields compared with control