UV curable coating formulation comprises urethane acrylate resin and nanosilica as filler were synthesized to develop UV curable inorganic organic hybrid composite (PUA). The surface of the nanosilica was chemically modified to improve its chemical interaction within the urethane acrylate matrix. The modification had been undertaken by applying vinyltrymetoxysilane (VTMOS) that acted as a coupling agent to produce organophilic silica shell (SIMA). The shell is linked to the silica via reaction with the surface silanol group of the silica. The disappearance of metoxy groups in VTMOS was demonstrated by FTIR spectrum. The percentage of silica particles in UV curable hybrid formulation were varied on 5%, 10%, 15%, 20% and 250% respectively. In this work, the formulation was applied on medium density fiber board (11/IDF) substrate and subsequent has been irradiated under UV light. Then, the coated MDF were characterized by several testing equipments (TGA, DSC, scratch tester, instron, SEM). From the result, we found that the addition of silica nanoparticles exhibit significant improvement in coating film properties as compared to film without silica nanoparticle includes significant improvement in its modulus and scratch resistance. This make them as promising coating candidate for MDF product. On the other hand, we also found that an increase of silica particle up to 25 wt%, the viscosity has increased rapidly indicates that it is not suitable for acrylate coating formulation due to disappearance of desired effect known as tixotrophy.
In these studies, cordierite was mechanically synthesized after a sol-gel process. The effect of milling time of cordierite was investigated. Aluminium nitrate nonahydrate, magnesium nitrate hexahydrate and tetraethylorthosilicate (TEOS) were used as starting materials. Gels obtained were mechanically activated in planetary ball mill by at 300rpm grinding speed and grinding time (15min, 30min, 45min and 60min). Powders produced were characterized by X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-Ray (EDX). XRD analysis proved that α-cordierite was formed at lower temperature (1200°C) as compliment to without grinding, whereby it is formed at1300°C. FESEM analysis shows the size of the cordierite were in submicron scale. EDX analysis proved that magnesium, aluminium, silicon and oxygen are elements existed in cordierite.
The issue of water quality is a never ended issue and becoming more critical when considering the presence of natural radionuclides. Physical parameters and the levels of radionuclides may have some correlation and need further attention. In this study, the former tin mine lake in Kampong Gajah was chosen as a study area for its past historical background which might contribute to attenuation of the levels of natural radionuclides in water. The water samples were collected from different lakes using water sampler and some in-situ measurement were conducted to measure physical parameters as well as surface dose level. The water samples were analyzed for its gross alpha and gross beta activity concentrations using liquid scintillation counting and in-house cocktail method. Gross alpha and beta analyzed using in-house cocktail are in the range of 3.17 to 8.20 Bq/L and 9.89 to 22.20 Bq/L; 1.64 to 8.78 Bq/L and 0.22 to 28.22 Bq/L, respectively for preserved and un-preserved sample. The surface dose rate measured using survey meter is in the range of 0.07 to 0.21 μSv/h and 0.07 to 0.2 μSv/h for surface and 1 meter above the surface of the water, respectively.
Recently, Malaysia has taken a positive step toward providing a better water quality by introducing more water quality parameters into its Water Quality Standard. With regard to the natural radionuclides that may present in the water, 3 parameters were introduced that is gross alpha, gross beta and radium which need to be measured and cannot exceed 0.1, 1.0 and 1.0 Bq/L respectively. This study was conducted to develop a more practical method in measuring these parameters in aqueous environmental samples. Besides having a lot of former tin mining areas, some part of Malaysia is located on the granitic rock which also contributes to a certain extent the amount of natural radionuclides such as uranium and thorium. For all we know these two radionuclides are the origin of other radionuclides being produced from their decay series. The State of Kelantan was chosen as the study area, where the water samples were collected from various part of the Kelantan River. 25 liters of samples were collected, acidify to pH 2 and filtered before the analysis. Measurement of these parameters was done using liquid scintillation counter (LSC). The LSC was set up to
the optimum discriminator level and counting was done using alpha-beta mode. The results show that gross alpha and beta can be measured using scintillation cocktail and radium and radon using extraction method. The results for gross alpha, gross beta, 222Ra and 226Ra are 0.39-6.42, 0.66-16.18, 0.40-4.65 and 0.05-0.56 Bq/L. MDA for gross alpha, gross beta and radium is 0.03, 0.08 and 0.00035 Bq/L respectively.
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.
The presence of 226 Ra in water is a great concern in human life since it can cause health risk to a certain extent. In the state of Kelantan, being known of its granitic area, there is a lack measurement of 226 Ra content in river water, since water is the major source of water supply. According to the INTERIM National Water Quality Standards for Malaysia (INWQS), 226 Ra activity concentration in water cannot exceed 0.1 Bq/L. For this reasons, this research was planned to carry out a systematic measurement of water along Sungai Kelantan. Liquid Scintillation Counting was used for measurement of 226 Ra in water samples from Sungai Kelantan mainly in district of Kuala Krai. In this paper, the results obtained is about 26 water samples, filtered and unfiltered, collected along Sungai Lebir, Sungai Sok and Bukit Sabah. Thus, the assessment activity concentration of 226 Ra in river water was obtained as well as annual effective dose for consumption of drinking water.
A modified potential of the sudden approximation, modified to include interactions among nuclei of different radii, is applied to explain the mass asymmetry of fission fragments in the thermal fission of Uranium-235. The results are encouraging in that the asymmetry feature in the fission yield is displayed. It appears that the mass asymmetry is a feature that can be explained without incorporating other effects. However, close correspondence requires addition of extra features.
Atmospheric Pollution due to airborne particle is a major concern to many cities in the Southeast Asian region, including Kuala Lumpur. Within the last six years air particulate samples have been collected from a site in Kuala Lumpur and measured for their PM10, PM2.5 and elemental concentrations. The results showed that the daily PM10 (
This work focuses on the use of X-ray tomography in investigating the flow distribution in a structured packed bed. Cross sections of the liquid hold up distribution in a 10 cm diameter column packed with Katapak-SP12 are obtained at various column heights for different liquid flow rates. The repartition of the liquid hold up between baskets and corrugated sheets is quantified. Wall wipers and column wall effects are visualized. Results are obtained from an initially dry column without gas flow.
The existence of Naturally Occurring Radioactive Materials (NORM) such as K-40 was studied all over the world for their characteristics and effects on human and environment. K-40 exist in the earth crust with the concentration about 1.8 mg/kg or 481 Bq/g.. In this study, the level of K-40 in soil samples were measured using gamma spectrometer equipped with hyper pure germanium detector. The samples were collected from an oil palm cultivated area of Jengka 15, in Maran District, Pahang. The results show the level of K-40 activities at various locations. The activities of K-40 are in the range 52.9-150.5 Bq/kg and total potassium concentrations are 1.60-4.50%. There are no correlation between activities of K-40 with elevation i.e. R2= 0.0885.
Polymer blends of 60/40 NR/HDPE were prepared using Brabender PL2000 Plasticorder with 60g capacity. The blends were added with radiation-sensitive natural rubber (NR)-based compatibilizer, known as LENRA. They were irradiated with electron-beam radiation at various doses. The efficacy of the compatibilizer was monitored by measuring various properties of the blends such as physical and dynamic mechanical properties including morphological studies by electron microscopic technique. Early results show that the addition of LENRA improves the properties of the TPNR blends.
Ceramic of BaxSr1-xTiO3 (BST) for x =0.3; 0.5 and 0.7 were successfully deposited by solid solution method. The BST ceramic were analyzed by x-ray diffraction (XRD). The XRD spectra was recorded on a Philips type PW 3701 diffractometer using CuKD (Oco = 1.54056 Å) radiation at 30 KV and 30 mA (900 watt). The spectra shows that BST ceramic are polycrystalline with tetragonal structure. The lattice constants analysis of the grown ceramics was analyzed by visual basic program. Using Cohen’s and Cramer’s algorithms in visual basic program, , the lattice constants are a = b = 3.877 Å; c = 3.970 Å for Ba0.3Sr0.7TiO3 ceramic, a = b = 3.979 Å; c = 3.981 Å. for Ba0.5Sr0.5TiO3 ceramic and a = b = 3.965 Å; c = 4.005 Å for Ba0.7Sr0.3TiO3 ceramic, respectively. The reform value of the lattice constant of BST ceramic is possibly associated with the anti site defects of Ba and Sr.
Neutrino is one of the nuclear particles that are necessary for the correct description of nuclear beta decay. The standard idea is that it is a massless neutral particle and its existence was postulated in order to save the conservation of ener gy principle. This particle was later detected experimentally and it is now known that neutrino has mass. The problem of astrophysical neutrino detection has produced a new phenomenon of neutrino oscillation where the three neutrino flav ours can oscillate between themselves. This paper studies the two component neutrino oscillation problem. We study the neutrino oscillation by using the Lagrangian formulation. In our study, we assume that the neutrinos are produced as n eutrino mass eigenstate and propagate in the vacuum in the superposition of two neutrino flavour state. The Lagrangian for neutrinos with their mass and the oscillation terms were obtained. By using the mass matrix in the Lagrangian, we formulate the time evolution operator in the interaction picture. The neutrino oscillation probability obtained by using the Lagrangian formulation have the same result with the one obtained by using quantum mechanics formulation. This study hopes to gain some deeper understanding into the behaviour of neutrino beyond the Standard Model.
A laboratory scale test rig to treat simulated flue gas using electron beam technology was installed at the Alurtron EB-Irradiation Center, MINT. The experiment test rig was proposed as a result of feasibility studies conducted jointly by IAEA, MINT and TNB Research in 1997. The test rig system consists of several components, among others, diesel generator sets, pipe ducts, spray cooler, ammonia dosage system, irradiation vessel, bag filter and gas analyzers. The installation was completed and commissioned in October 2001. Results from the commissioning test runs and subsequent experimental work showed that the efficiency of flue gas treatment is high. It was proven that electron beam technology might be applied in the treatment of air pollutants. This paper describes the design and work function of the individual major components as well as the full system function. Results from the initial experimental works are also presented.
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.
The amount of sugarcane bagasse and rice straw in the state of Perlis (Malaysia) is abundant while its utilization is still limited. One of the alternatives for the bagasse and straw utilization is as pulp raw material. This paper reviews on pulp from sugarcane bagasse and rice straw and its suitability for paper production. In this study, the pulp was extracted by the Soxhlet extraction method. The objective of this study was to investigate the cellulose, lignin and silica content of the pulp from sugarcane bagasse and rice straw. For rice straw, the presence of large amount of pentosanes in the pulp and black liquors, which also contain silica were decreased the using of straw in the paper industry. Therefore, formic acid pulping and NaOH treatment are studied to reduce or prevent silica. The isolated pulp samples were further characterized by Scanning Electron Microscope (SEM) to investigate their fiber dimensions.
In this study the intermetallic (IMC) thickness of Sn-Pb, Sn-Zn and Sn-Zn-Bi solders on copper (Cu) substrate were measured at different temperatures using reflow methods. Cu6Sn5 intermetallic phase was detected between Sn-Pb solder and Cu substrate. The J-Cu5Zn8 phase was detected between Sn-Zn and Sn-Zn-Bi lead-free solders with Cu substrate. The thickness of the intermetallics increases with temperature. The IMC thickness for Sn-8Zn-3Bi solder is lower than Sn-9Zn solder for all the soldering temperatures, indicating that Bi has suppressed the initial IMC formation.
Surface free energies have been evaluated from Young’s moduli and lattice parameter data of five aluminium alloys with varying amounts of stanum to determine the inter-correlation with anode capacity of the alloys. The composition containing ~1.47%Sn exhibits a minimum in the surface free energy which accounts for the decrease in the tendency of the alloy to undergo passivation thus resulting in a higher anode capacity of 2478Ah/kg at ≈ 0.08mA/cm 2 , current density. The results showed that aluminium alloy containing certain amount of stanum has lowered surface free energy, leading to reduction in passive film thickness and reduces metal/oxide bond strength. These factors in turn result in a better cathodic protection property of aluminium alloy containing stanum.
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.
Hydroxyapatite (HA) powder was synthesized via wet method using calcium nitrate hydrate (Ca(NO3)2.H2O) and diammonium hydrogen phosphate ((NH4)2HPO4) as raw materials. Powder obtained was milled using various milling speed ranging from 250 to 400 r.p.m. and sintered at 1300°C for 2hrs. Due to the nature of HA powder that decomposed at high temperature, XRD technique have been used in this work to determine the phase composition of the HA powder and also the crystallite size. The unmilled sample was used as the control group. Results show that sufficient heat supply generated from the milling process, initiates the decomposition of HA phase into ȕ-tricalcium phosphate (ȕ-TCP). Decomposition of HA starts to occur at the milling speed of 300 rpm, i.e the formation of ȕ-TCP was occurred at lower sintering temperature. It was believed that the decomposition of HA was associated with the formation of an intermediate phase, oxyapatite. Moreover, the crystallinity and particle size of the produced powder is very much affected by the milling speed and the stability of the HA. All milled powders possess spherical shape particle.