Displaying publications 61 - 80 of 173 in total

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  1. Hassan, M.F., Azimi, N.S.N., Kamarudin, K.H., Sheng, C.K.
    ASM Science Journal, 2018;11(101):17-28.
    MyJurnal
    Solid polymer electrolytes based on starch as a polymer host and Magnesium Sulphate
    (MgSO4) as an ionic dopant were successfully prepared by a single-solvent via solution casting
    technique. As determined by XRD and FTIR analyses, the solid polymer electrolyte films
    were in amorphous phase and the coexistence of peaks of the materials (starch and MgSO4)
    confirming that the complex films were successfully obtained. The SEM observations showed
    the films appeared to be rough and flat shape of surface. The highest ionic conductivity (σ)
    of 8.52 ×10−5 S cm−1 was achieved at room temperature (303K) for the sample containing 35
    wt.% MgSO4. The presented results revealed that the as-prepared solid polymer electrolyte
    has the potential as dual functional compound in electrochemical storage application.
  2. Hii, Y.S., Alias, S.A., Hussin, A., Zakaria, M.P., Moreano, H., Riofrio, M., et al.
    ASM Science Journal, 2009;3(2):143-151.
    MyJurnal
    Surface coverage and some properties soil chemicals were assessed at the Punta Fort William, Greenwich Island during the summer from 1–11 February 2008. Twenty sampling points were established along two strip transects covering a total area of 160 m2. Punta Fort William was basically barren. Rocks, stones and pebbles covered 89.4% of the Punta Fort William. The diversity of vegetation in Punta Fort William was relatively low as compared to other South Shetland Islands. Mosses predominated the area and covered 9.1% of the total surface. Colobantus quitensis was the only vascular plant found at the Punta Fort William. It covered 0.5% of the total surface area. Lichens contributed 0.2% of the surface coverage. Although lichen coverage was low, its frequency of occurrence was among the highest. Total organic carbon (TOC) and total nitrogen (TN) in the study area ranged from 1 g to 39 g C kg–1 and 12 μg to 3892 μg N kg–1, respectively. The level of TOC and TN were comparable to those reported in other maritime locations in Antarctic. Higher levels of TOC and TN were detected in the areas with intensive biological activities. Hydrocarbon concentration was very low in this area and the sources of hydrocarbons were both natural and anthropogenic. The natural hydrocarbons source was mostly biogenic while the petrogenic hydrocarbons input was anthropogenic.
  3. Ibrahim, Ahmad1
    ASM Science Journal, 2015;9(1):28-29.
    MyJurnal
    The first time I visited Kuching, Sarawak, was in the 1980s. I then worked for the Rubber Research Institute of
    Malaysia. In the 1980s, Kuching was a small town. I remember that then, the route going to the airport was lined with
    shops selling the famous Sarawak vases. They were a big hit among visitors. A visit to Sarawak was not complete
    without taking back a set of the black-and-white vases. They came in many shapes and sizes(Copied from article).
  4. Ibrahim, R.W., Darus, M.
    ASM Science Journal, 2008;2(1):93-100.
    MyJurnal
    We have considered a fractional integral operator in this study. By using this integral operator we obtained a Briot-Bouquet superordination and sandwich theorem.
  5. Indah M Amin, Mohd Ridzuan Hamid, Dayang Zahidah A. Othman, Rosfaiizah Siran, Siti Hamimah S.A. Kadir, Narimah AH Hasani
    ASM Science Journal, 2014;8(2):165-173.
    MyJurnal
    Aloe emodin, an anthraquinone of Aloe barbadensis Miller has been shown to have more cytotoxic effect in
    different kinds of human cancer cell lines compared to normal. Accordingly, we found it to selectively inhibit
    the proliferation of oestrogen-receptor-positive-(ER+)-breast cancer cells, MCF-7; but not controls cells,
    MCF-10A. However, its precise mechanism is not well understood. Several studies have shown that there is
    evidence of increased intracellular calcium (Ca2+), both at early and late stage of apoptosis which associated
    with the down-regulation of ERK1/2 proliferative pathway. Therefore, we aim to elucidate the involvement
    of intracellular Ca2+ in aloe emodin induced apoptosis on MCF-7. Apoptotic morphological changes were
    observed under fluorescence microscope. The involvement of cytoplasmic Ca2+ and MAPKs were investigated
    using Fluo-4 intracellular Ca2+ imaging and QuantiGene 2.0 Plex assay, respectively. IC50 of aloe emodin
    (80 μM) at 72 hours incubation was used. Data were evaluated using the one-way or two-way ANOVA tests.
    Our results indicated that aloe emodin at IC50 80µM induced apoptosis on MCF-7 through the association of
    intracellular Ca2+ signalling. This observation include a significant increased (p
  6. Islam, M.R., Muthuraju, S., Tarmizi, C.H., Zulkifli, M.M., Osman, H., Mohamad, H., et al.
    ASM Science Journal, 2012;6(2):95-102.
    MyJurnal
    Epilepsy is a neurological disorder characterized by recurrent seizures resulting from excessive abnormal electrical discharges in the brain. Medicinal plants may play an invaluable role to discover the new antiepileptic drugs. The aim of the present study was to investigate the anticonvulsant activity of α-terpineol isolated from Myristica fragrans Hountt. The α-terpineol showed a significant inhibition of the seizure episodes and spikes in absence seizures model of Genetic Absence Epilepsy Rats from Strasbourg (GAERS) rats by using electroencephalography records. It showed dose-dependent anticonvulsant activity that was comparable to the known antiepileptic drug of diazepam. It showed a rapid onset and relatively short duration of anticonvulsant effects. The present findings suggest that α-terpineol might possess antiepileptic activities against the partial seizures of human because it prevented seizures in well-established genetic absence seizure animal model of GAERS rats.
  7. Ismail, A.
    ASM Science Journal, 2007;1(2):169-175.
    MyJurnal
    As we move towards the knowledge (K) era, the challenge in R&D is to focus on the development of original K-based products that can compete in the global market. The development of commercially viable, patented K-based products within a university environment require an innovation system and innovation policies in place and a change in the paradigm towards the approach to research. A crucial agent towards the success of the innovation system is development and training of the human capital that would be the future drivers of the K-industry. Awareness of intellectual property rights, the need for original research, entrepreneurship as well as the development and strengthening of self-confidence and leadership are among the factors needed towards the training of K-workers facing the new economy.
  8. Issa, R., Hamdan, N.A., Raj, A.S.S., Noh, M.F.M.
    ASM Science Journal, 2011;5(1):36-42.
    MyJurnal
    Researchers have developed and modified DNA biosensor techniques to provide a fast, simple and sensitive method for detection of human diseases, bacterial food contamination, forensic and environmental research. This study describes the physical characterization of screen-printed carbon electrodes using the scanning electron microscope.
  9. Jaaman, S.A., Mohamed, C.A.R.
    ASM Science Journal, 2014;8(2):143-149.
    MyJurnal
    Marine mammal searches were opportunistically conducted during the East Coast Johor Scientific Expedition (ECJSE) on 21-30 May 2012, on a live-on-board (LOB) diving vessel, MV BLACK PEARL. The expedition was designed mainly to survey coral reef ecosystems and water quality. Daylight visual observations of the sea were undertaken during sailing and stopping/anchored from the most upper open-deck of the vessel. The survey resulted in two sightings of long-beaked common dolphins (Delphinus capensis), each at Pulau Aur and Pulau Tinggi. Both observations were brief (< 5 minutes) and were made when the vessel was anchored. Based on anecdotal evidences, skeletal remains and previous surveys, the vulnerable dugong, Indo-Pacific bottlenose, Indo-Pacific humpback, Irrawaddy and long-beaked common dolphins, the false killer and pygmy killer whales, and the baleen whales are known to occur in the East Coast Johor waters, at least occasionally. The low sighting rate with marine mammals during this survey is highly likely caused by the survey design and also may be due to the environmental conditions and ecological factors. Dedicated and periodical boat and aerial surveys for marine mammals need to be conducted to determine species diversity and to understand the seasonality, habitat use, and social interactions of the marine mammal populations in the area. The findings will be most useful for marine park and fisheries authorities to plan conservation management strategies for marine mammals and promote their conservation through eco-tourism activities.
  10. Jamuna, K., Noorsal, K., Zakaria, F.A., Hussin, Z.H.
    ASM Science Journal, 2010;4(1):41-47.
    MyJurnal
    Introducing CO2 flux as the carbonate source had an effect on the carbonate content of carbonate apatite (CAp) synthesized by solid state reaction. The reactants were CaCO3 and beta-tricalcium phosphate (β-TCP) and the heat treatment in air was performed at 1250ºC followed by instant cooling in CO2 flux for temperatures ranging from 800ºC room temperature (RT) . The influence of CO2 flux at various temperature drop differences in the cooling process (1250ºC RT, 1250ºC–500ºC, 1250ºC–600ºC, 1250ºC–700ºC, and 1250ºC–800ºC) was tested to optimize the carbonation degree and subsequent effects on the physical and mechanical properties of CAp. Thermally treated samples revealed an increasing degree of carbonation, achieving a maximum of 5.2 wt% at the highest (1250ºC RT) and a minimum of 2.7 wt% at the lowest (1250ºC–800ºC) temperature drop differences, respectively. This showed that the carbonate content was correlated with the increase in exposure to CO2 flux. However, consistent compressive strength, tensile strength, density and porosity were observed against increasing temperature drop differences which indicated that the degree of carbonation exerted no influence on the physical and mechanical properties of CAp. This method enabled the synthesis of solid state CAp simply by exposing calcium phosphate mixtures to CO2 flux. It also allowed the control of carbonate content for desired medical applications.
  11. Jawari, M.S.A., Chen, S.K., Halim, S.A., Talib, Z.A., Lee, O.J.
    ASM Science Journal, 2018;11(101):1-7.
    MyJurnal
    Exploiting the merits of superconducting properties, a series of thermal profile was employed
    to modify the melt-textured growth of Y−Ba−CuO bulk with BaTiO3 epitaxial
    crystal seed. Two thermal routes were used whereby multiple heatings of the samples were
    conducted at 940 ◦C and 960 ◦C before elevating to 1040 ◦C and 1070 ◦C, respectively. Our
    finding shows that the optimum melt-textured growth window is narrow within the temperature
    range of 1010−1040 ◦C. Above the peritectic temperature, partial decomposition of
    YBa2Cu3O7−δ (Y123) into YBa2Cu3O5 (Y211) leads to the formation of Y211 multigrains
    embedded in the matrix of Y123. The values of Tc for the superconducting Y123 obtained
    using the two routes are 78 K and 71 K. The lower Tc suggests the presence of structural
    distortion and non-stoichiometry of the samples.
  12. Jesudason, C.G.
    ASM Science Journal, 2007;1(1):7-18.
    MyJurnal
    Molecular dynamics reaction simulation showed that the rate constant is not constant over the concentration profile of reactants and products over a fixed temperature regime, and this variation is expressed in terms of the defined reactivity coefficients. The ratio of these coefficients for the forward and backward reactions were found to equal that of the activity coefficient ratio for the product and reactant species. A theory was developed to explain kinetics in general based on these observations. Several other theorems had first to be developed, most striking of all was the inference that the excess Helmholtz free energy was the thermodynamical function which had a direct relation to these activity factors than the Gibbs free energy. The theory is applied to a class of ionic reactions which could not be rationalized using the standard Bjørn-Bjerrum theory of ionic reactions.
  13. Kadir, M.A., Kassim, N., Ku Bulat, K.H., Mehamod, F.S.
    ASM Science Journal, 2018;11(101):136-146.
    MyJurnal
    A paradigm shift in supramolecular chemistry has drawn our attention to produce coordination
    polymers for anion separation. In this approach, we have successfully synthesized a
    one dimensional coordination polymer from combination of U-shaped diamide ligand, namely
    N,N -2,6-bis(4-pyridylmethyl)pyridine dicarboxamide (L1) and Zn(NO3)2 in methanol. This
    product is obtained as single crystal with formula molecule given by elemental analysis as
    {[Zn(L1)2(H2O)2](NO3)2.4H2O}n. In this account, we also describe supramolecular interactions
    between this coordination polymer with two selected anions, nitrate and chromate
    using combination of experimental and theoretical studies. Observation via FTIR spectra
    indicates the presence of two distinctive peaks for Cr-O (931 cm−1
    ) and N-O (1384 cm−1
    )
    confirming encapsulation of chromate and nitrate anions in the receptor. X-ray crystallography
    reveals the interaction between NH amide with the anions as expected. As resulted
    by Gaussian, coordination polymer with nitrate anion is found more stable compared to
    chromate with interaction energy 342.2729 kJ/mol.
  14. Kamal, Z.Z., Daud, A.H.M., Ashidi, M.I.N., Fadel, J.K.M.
    ASM Science Journal, 2007;1(2):87-100.
    MyJurnal
    Covering as much as 25% to 35% of the development cost, software testing is an integral part of the software development lifecycle. Despite its importance, the current software testing practice is still based on highly manual processes from the generation of test cases (i.e. from specifications) up to the actual execution of the test. These manually generated tests are sometimes executed using ad hoc approaches, typically requiring the construction of a test driver for the particular application under test. In addition, test engineers are also under pressure to test increasing lines of code in order to meet market demands for more software functionalities. While there are significant proliferations of helpful testing tools or research prototypes in the market, much of them do not adequately provide the right level of abstraction and automation as required by test engineers. In order to facilitate and address some of the aforementioned issues, an automated testing tool was developed, called SFIT, based on Java® technology. This paper describes the development, implementation and evaluation of SFIT. Two case studies involving the robustness assessment of an adder module and a Linda-based distributed shared memory implementation are described in order to demonstrate the applicability of SFIT as a helpful automated testing tool.
  15. Kamarudin, K.H., Isa, M.I.N., Hassan, M.
    ASM Science Journal, 2018;11(101):29-36.
    MyJurnal
    Supercapacitors attract great interest among researchers as energy storage devices due to
    their high power capability and long cycle life. In this research, the electrochemical performance
    of electrical double layer capacitor (EDLC) based solid bio-polymer electrolyte
    (SBE) was studied. SBE consists of carboxymethyl cellulose (CMC) and ammonium nitrate
    (NH4NO3) was prepared by solution casting technique. The electrical impedance spectroscopy
    was used to verify the conductivity of SBE. The average conductivity was achieved
    at ∼ 10−3 S/cm. This research aims to prepare SBE and apply in the fabrication of EDLC.
    Scanning electron microscopy analysis showed the smooth and homogeneous surface of SBE
    film without any phase separation, while irregular shape and sizes of particles was found
    on the surface of electrode. Elemental identification results yielded that all corresponding
    elements presence in the SBE and electrode. The EDLC performance was characterized
    using galvanostatic charge-discharge at different constant currents. Charge-discharge studies
    showed that long discharge time (90 minutes) within 11 cycle was observed at 2µA. The
    highest specific capacitance of 1.8 F/g was discovered at 4µA. This study showed that EDLC
    based SBE has a promising potential to be applied in low current applications.
  16. Kamarudin, K.S.N., Chieng, Y.Y., Hamdan, H., Mat, H.
    ASM Science Journal, 2008;2(1):35-44.
    MyJurnal
    The importance of zeolite surface area and pore volume in adsorption processes has been much reported in literature. In addition to that, structural framework and pore network system may also influence the adsorption capacity and selectivity of methane on zeolite. This paper discusses the characteristics of methane adsorption based on several physical properties of the adsorbents such as surface area, pore volume, pore network system and its interaction with adsorbate. The study, using FTIR spectroscopy showed that the adsorbed methane at room temperature was detected in the FTIR region between 3200 cm–1 – 1200 cm–1. Based on the physical properties of the adsorbents and the FTIR spectra of adsorbed methane, the surface area was not the only factor that determined methane adsorption; in fact the type of pore network system of the adsorbent also affected the interaction, thus affecting the adsorption of methane in zeolite.
  17. Kamarudin, K.S.N., Chieng, Y.Y., Hamdan, H., Mat, H.
    ASM Science Journal, 2010;4(1):29-40.
    MyJurnal
    Ordered microporous NaY zeolite and mesoporous copper oxide are high performance material as catalysts and adsorbents. The copper oxide-NaY zeolite modification in combination of their physicochemical properties could provide excellent opportunities for the creation of new gas adsorbents. In this study, modified NaY zeolite properties and methane adsorptive characteristics were investigated by dispersing copper oxide onto the NaY zeolite structure using the thermal dispersion method. The structures of the copper oxide modified zeolites were characterized by powder X-ray diffraction and Micromeritics ASAP 2000, while the methane adsorption characteristics were analyzed using a thermogravimetric analyzer. The results revealed that types of copper oxide, copper oxide loading concentration, calcination temperature and calcination time greatly affected the modified zeolite structure and gas methane adsorption characteristics.
  18. Kandasamy, R., Azme, Hashim, I., Ismoen, M.
    ASM Science Journal, 2008;2(1):23-33.
    MyJurnal
    The effect of chemical reaction and variable viscosity on mixed convection heat and mass transfer for Hiemenz flow over a porous wedge plate was studied in the presence of heat radiation. The wall of the wedge was embedded in a uniform Darcian porous medium to allow for possible fluid wall suction or injection and had a power-law variation of both the wall temperature and concentration. The fluid was assumed to be viscous and incompressible. Numerical calculations were carried out for different values of dimensionless parameters and an analysis of the results obtained showed that the flow field was influenced appreciably by the buoyancy ratio between species, thermal diffusion and suction/injection at wall surface. The effects of these major parameters on the transport behaviours were investigated methodically and typical results illustrated to reveal the tendency of the solutions. Representative results are presented for the velocity, temperature, and concentration distributions. Comparisons with previously published works were performed and excellent agreement between the results were obtained. It is predicted that this research might prove to be useful for study of the movement of oil or gas and water through the reservoir of an oil or gas field, in the migration of underground water, in filtration, and water purification processes.
  19. Kassim, K.M., Davarnejad, R.
    ASM Science Journal, 2007;1(2):143-154.
    MyJurnal
    The objective of this paper is to model the extraction of carotenoid with supercritical carbon dioxide as the solvent. Experimental data for the high pressure vapour-liquid phase equilibrium of the binary system carbon dioxide-carotenoid was reviewed for the elevated temperatures of 313.15, 323.15, 333.15 K and pressures up to 500 bar. The experimental data was correlated and modeled using Redlich-Kwong equation of state and regular solution methods. The use of the equation of state as an empirical correlation for collating and predicting liquid-liquid and liquid-dense fluid equilibria is discussed. It was concluded that the estimation of some of the parameters required for these calculations would be difficult if the solute (carotenoid) was a complex substance about which little was known apart from its structural formula. An alternative procedure is to apply activity coefficient expression of the regular solution theory type to each phase. Calculations along these lines are described and the physical basis for applying these methods under the relevant conditions is discussed. The regular solution theory approach in particular was found to be encouraging for the mutual miscibility calculations for heavy components (such as carotenoid) particularly for substances sensitive to temperature, though the interaction parameters for he prediction activity coefficients must be regarded as pressure dependent.
  20. Kassim, S., Tahrin, R.A.A., Rusdi, N.F., Harun, N.A.
    ASM Science Journal, 2018;11(101):86-95.
    MyJurnal
    A feasible production of poly (methyl methacrylate)@alloy (gold-silver) core shell has
    been presented as candidate in enhanced detection of surface enhanced Raman scattering
    (SERS). Free emulsifier- emulsion synthesised PMMA sphere with average size of 419 nm in
    diameter were used as core material for incorporation of alloy nanoparticles (6 nm) resulting
    a core-shell structure. The fabrication of PMMA@alloy SERS substrate was successfully
    done via self-assembly thus the produced SERS substrate that comprise of unique optical
    properties combination arising from periodic core arrangement and plasmonic activity of
    alloy nanoparticles. Alloy is bimetallic nanoparticles in which the combination of silver
    (Ag) and gold (Au) present an absolutely improved light resistance as compared to single
    metal alone with great surface plasmon resonance. Morphology and elemental analysis was
    performed through scanning electron microscope (SEM) and the analysis showing species of
    both Au and Ag in single alloy nanoparticles. The alloy nanoparticles were also observed to
    homogenously coating the PMMA sphere. Surface plasmon resonance activity was maximum
    at 476 nm obtained from UV-Visible spectroscopy. High surface production was observed
    to have periodically arranged PMMA@alloy core -shell and potentially to be used as SERS
    substrate.
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