Displaying publications 81 - 100 of 173 in total

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  1. N. Sulaiman, B. Y. Majlis
    ASM Science Journal, 2013;7(1):27-36.
    MyJurnal
    Measurement of low magnetic field has played an important role in many electronics applications such as navigation, military, non-destructive test, traffic detection as well as medical diagnosis and treatment. The presence of magnetic field, particularly its strength and direction, can be measured using magnetometer. There are many types of magnetometers being investigated through the years and one of the prominent types is fluxgate magnetometer. The main components of fluxgate magnetometer consisting of driving coils, sensing coils and magnetic core are developed by MEMS silicon processing technology. In this paper, an investigation on physical characteristics of the three-dimensional coil structure for a micro-scaled fluxgate magnetometer is presented. The physical characteristics such as width of the coil, distance between successive coils, and gap between the top and bottom coils which would influence the magnetic energy in magnetometer is discussed. In this work, finite-element method simulations to investigate the physical characteristics of the sensing coils were carried out, where the parameter of interest is the coils’ inductance as well as the magnetic flux density. Based on the simulation results, the varying of physical characteristics of the coils had its effects particularly in coil inductance, magnetic flux density, and magnetic energy. It could also be seen that the simulated results agreed with the theoretical aspects of magnetism in a coil. From the investigations, suitable coil dimensions were proposed.
  2. Yusoff, A.N., Mohamad, M., Hamid, K.A., Hamid, A.I.A., Manan, H.A., Hashim, M.H.
    ASM Science Journal, 2010;4(2):158-172.
    MyJurnal
    In this multiple-subject study, intrinsic couplings between the primary motor (M1) and supplementary motor areas (SMA) were investigated. Unilateral (UNIright and UNIleft) self-paced tapping of hand fingers were performed to activate M1 and SMA. The intrinsic couplings were analysed using statistical parametric mapping, dynamic causal modeling (DCM) and Bayesian model analysis. Brain activation observed for UNIright and UNIleft showed contralateral and ipsilateral involvement of M1 and SMA. Ten full connectivity models were constructed with right and left M1 and SMA as processing centres. DCM indicated that all subjects prefer M1 as the intrinsic input for UNIright and UNIleft as indicated by a large group Bayes factor (GBF). Positive evidence ratio (PER) that showed strong evidence of Model 3 and Model 6 against other models in at least 12 out of 16 subjects, supported GBF results. The GBF and PER results were later found to be consistent with that of BMS for group studies with high expected posterior probability and exceedance probability. It was concluded that during unilateral finger tapping, the contralateral M1 would act as the input centre which in turn triggered the propagation of signals to SMA in the same hemisphere and to M1 and SMA in the opposite hemisphere.
  3. Ng, W. L., Tan. S.G.
    ASM Science Journal, 2015;9(1):30-39.
    MyJurnal
    Inter-simple sequence repeats (ISSRs) are regions in the genome flanked by microsatellite sequences.
    PCR amplification of these regions using a single primer yields multiple amplification products that can
    be used as a dominant multilocus marker system for the study of genetic variation in various organisms.
    ISSR markers are easy to use, low-cost, and methodologically less demanding compared to other
    dominant markers, making it an ideal genetic marker for beginners and for organisms whose genetic
    information is lacking. Here, we comment upon some of the intricacies often overlooked in designing an
    ISSR experiment, clarify some misconceptions, and provide recommendations on using ISSR markers
    in genetic variation studies.
  4. Reza, F., Begum, T., Ahmed, A.L., Omar, H., Muzaimi, M., Abdullah, J.M.
    ASM Science Journal, 2012;6(1):39-45.
    MyJurnal
    The human brain generates different oscillations at different frequencies during various consciousness levels. When these brain waves synchronize with exogenous rhythmic stimulation, the brain experiences strong, yet relaxing emotion that could be involved in the formation of memory. We investigated the character of rhythmic oscillatory dynamics by electroencephalography (EEG) of subjects listening to a short verse of the Holy Quran compared to resting and Arabic news listening. The mean power amplitudes of each frequency band for wavelet-based time-frequency analysis were obtained from 5000 ms of segmented EEG recordings during rest, news and Quran listening conditions. The time series analysis of power from each of three conditions in each frequency band from the grand averaged data was then subjected to autocorrelation study. The results showed significant cyclic overall trends of increasing and decreasing patterns of power in the low frequency brain wave oscillation of different head regions especially global, frontal and temporal sites. These results provided a basis for prediction of the periodicity of the power of the oscillatory brain dynamics of delta and robustly in theta regions which occurred during Quran listening. Despite several limitations, our data offered a plausible scientific basis to the emotional induction during Quran listening that mimics recognized as data from music listening studies. This offered a promising perspective for future studies in translational neurophysiological, cognitive and biofeedback on Quran listening to modify brain behaviour in health and disease.
  5. Chu, W.L., Phang, S.M., Lim, S.L., Teoh, M.L., Wong, C.Y.
    ASM Science Journal, 2009;3(2):178-183.
    MyJurnal
    Chlorella is one of the common microalgae found in a wide range of habitats, including Antarctica. Chlorella UMACC 234 is an interesting isolate in the collection of Antarctic microalgae in the University of Malaya algae culture collection (UMACC) as it grows well at temperatures much higher than the ambience. The alga was isolated from snow samples collected from Casey, Antarctica. This study investigates the influence of nitrogen source on the growth, biochemical composition and fatty acid profile of Chlorella UMACC 234. The cultures were grown in Bold’s Basal Medium with 3.0 mM NaNO3, NH4Cl or urea. The cultures grown on NaNO3 attained the highest specific growth rate (μ = 0.43 day–1) while the specific growth rates of those grown on NH4Cl and urea were not significantly different (p > 0.05). The urea-grown cells produced the highest amounts of lipids (25.7% dry weight) and proteins (52.5% dry weight) compared to those grown on other nitrogen sources. The cell numbers attained by the cultures grown at NaNO3 levels between 0.3 and 3.0 mM were similar but decreased markedly at 9.0 mM NaNO3. The fatty acids of Chlorella UMACC 234 were dominated by saturated fatty acids, especially 16:0 and 18:0. The percentage of polyunsaturated fatty acids was very low, especially in cells grown on urea (0.9% total fatty acids). Characterisation of the growth and biochemical composition of this Antarctic Chlorella is important to our studies on the relationship of Chorella isolates from tropical, temperate and polar regions, especially in terms of phylogeny and stress adaptation.
  6. Abdullah, M.A.A., Mamat, M., Rusli, S.A., Kassim, A.A.
    ASM Science Journal, 2018;11(101):96-104.
    MyJurnal
    Considering its excellent thermal stability, alkyl phosphonium surfactant: triisobutyl(methyl)phosphonium
    (TIBMP) was used in this research as an intercalant for surface
    modification of Na+-MMT via ion exchange process forming organomontmorillonite
    (OMMT). The OMMT was then used as filler in poly(methyl methacrylate) (PMMA) via
    melt intercalation technique. OMMT decomposed at a higher temperature than commercial
    alkyammonium modified MMT. Exfoliated and intercalated types of nanocomposites
    are obtained from PMMA/OMMTs at low and high content of OMMT loading, depending
    on the space of those clay platelets had to disperse in PMMA. The ability of OMMT to
    carry a certain load applied in PMMA matrix enhances the tensile strength in all composites.
    TIBMP are compatible with PMMA matrix, and significantly improves the tensile
    properties of PMMA composites.
  7. 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.
  8. Suratman, S., Tawnie, I., Sefei, A.
    ASM Science Journal, 2011;5(2):101-107.
    MyJurnal
    A study to determine the impact of leachate from operating and closed landfills into the surface water and groundwater systems in the state of Selangor was conducted in the year 2009. Groundwater was a major source of water for various uses in Selangor, Malaysia and was especially important for industrial purposes. The presence of high numbers of landfill sites was seen to have increased the risk of groundwater contamination. There were 20 landfill sites in the state of Selangor and seven of them were still operating and 13 closed. The landfills are classified into four categories, which were: (a) landfills operating at critical stages without controls to prevent pollution into the environment; (b) open dumpsites that have the capacity to continue to accept waste but needed to be upgraded to manage leachate and gas; (c) landfills that were closed but no safety closure plan was carried out; and (d) engineered landfills with up to date technologies. As most of the landfills were built prior to 1989, they were not subjected to the Environmental Impact Assessment requirements, hence, they were being poorly managed and were badly sited. The non-engineered sites had no proper pollution controls such as cover materials, liner materials, groundwater monitoring wells, leachate collection ponds and treatment, and methane gas collection pipes. This study revealed that the surface water and groundwater at and nearby the landfill sites were contaminated at various levels due to the landfill sites and operation. A comparison between the current quality of surface water and groundwater with their respective standards and background levels was carried out to survey the trend of the contamination. However, the limited financial resources hindered a very thorough investigation and restricted the number of samples collected and parameters analysed.
  9. Mohd Armi, A.S., Afiza, A.S., Mohd Ramzi, A.
    ASM Science Journal, 2012;6(2):149-151.
    MyJurnal
    Over the last century, the earth’s climate has changed. It is a serious global, long-term problem which involves complex interactions. A lot of evidence suggests that most of the observed factors contributing to the crisis over the last 50 years can be attributed to human activities. Malaysia has always been vulnerable to extreme climatic events such as typhoons, floods and drought. We expect climate change to exacerbate these vulnerabilities. To ensure, that our water resources will always be secure and ready for use. We need to create awareness in the public and the policy makers so that they will acknowledge that the climate change issue is real. They also need to accept that actions to adapt with our vulnerabilities should be immediately put in place. We can do this by integrating the various sector policies and securing the participation of all stakeholders in Malaysia and other countries.
  10. Devendra, C.
    ASM Science Journal, 2011;5(2):139-150.
    MyJurnal
    The effects of anticipated climate change and the potential impact on animal production are discussed in the context of varying biophysical features, agro-ecological zones (AEZs), ecosystems, land use, and responses in animal genetic diversity and production. The AEZs in Asia have great diversity in their links to food production in crop-animal small farm systems, the poverty complex and livelihoods of the poor. In these environments. climate change effects on animals were mediated through heat stress, water availability, quantity and quality of the available feed resources, type of production system and productivity. The responses to heat stress are tabulated and they vary according to species, breeds within-species, AEZs, physiological and nutritional status, genetic potential and multifunctionality. Among ruminant production systems, dairy production was especially vulnerable to heat stress. Interestingly in India, buffalo numbers owned largely by the landless and small farmers in the semi-arid and arid regions have grown twice as fast as the buffalo population in the irrigated areas. The implications and strategies to cope with climate change involve mitigation, adaptation and policy. The principal strategy is targetting to the reduce on in greenhouse gas (GHG) emission from the agricultural sector from enteric fermentation and manure, and ways to intensify C sequestration. An important link is that of breeding and conserving indigenous animal genetic resources as a means to mitigate climate change, with associated benefits to the trade of live animals and animal products. Improved integrated tree crops-ruminant systems are an important pathway to enhance C sequestration. The opportunities for research and development (R&D) are enormous and they would need policy support and large investments to provide improved understanding of ways to ensure sustainable animal production systems. Coping with the totality of the effects and impact of climate change constitutes the challenges for agricultural R&D and the improved livelihood of the resource-poor in the future.
  11. Suparta, W., Samah, A.A., Harper, A.R.
    ASM Science Journal, 2009;3(2):152-160.
    MyJurnal
    Katabatic winds dramatically affect the polar climate. Their activity depends on density of air and temperature in the source region. This paper presents for first time an analysis of the precipitable water vapour (PWV) variability and its relation to a katabatic event at Scott Base station, Antarctica. A significant effect in their characteristics toward calculation of a reliable user accuracy in GPS applications is addressed. Our investigations using the data between 21st and 30th of November 2002 showed that the PWV profile exhibited an irregular pattern with a maximum value of 7.38 mm (~ 6 mm on average), and was more strongly influenced by relative humidity than by wind speed activity. The dominant wind flow during this period was from the North-Northeast (blowing from the Ross Sea) with a median speed of 4.96 ms–1. The PWV was high when the temperature was between –15ºC and –11ºC. During the dates identified as a katabatic event between 21:30 UT of 28th November and 18:40 UT on 29th November, the wind blew from the Southeast-South direction (from the Ross Ice Shelf) with a maximum speed of 10.92 ms–1. The PWV increased ~1.4 mm (23%) from the mean value, indicating severe wind during this event which had pronounced effect on GPS observations.
  12. Al-Bayaty, F.H., Al-Tay, B.O., Al-Kushali, S.S., Mahmmod, L.
    ASM Science Journal, 2009;3(1):45-50.
    MyJurnal
    A study was undertaken to estimate the histological changes of gingival enlargement induced by
    Cyclosporin A (CsA) and Nifedipine, separately and in combination. Twelve adult rabbits were divided equally into four main groups. The first group received 10 mg/kg/day Nifedipine, the second received 10 mg/kg/day CsA, and the third received a combination of 10 mg/kg /day Nifedipine and CsA by gastric feeding. The fourth was regarded as a control group. Animals were given the drugs from day 1 of the experiment until day 70. They were then sacrificed for histological purposes. Results showed increase in the thickness of the epithelium with keratosis and acanthosis, and also increased vascularity. Collagen fibres and fibroblasts at different rates in the three histological groups were observed. Significant alveolar bone resorption with increased marrow spaces filled with fatty tissue were found in the CsA group. Non-significant changes in the alveolar bone of the Nifedipine group while subsequent bone resorption and bone deposition were seen in the combination group. These changes could be due to the effect of both drugs. Significant changes in the gingiva and the alveolar bone were shown in the three experimental groups compared with the control group.
  13. Djauhari, M.A.
    ASM Science Journal, 2016;9(2):1-8.
    MyJurnal
    The paradigm that mathematics is a subject to be taught and learned is not correct. Mathematics is to be
    produced. However, without hermeneutics, it would be difficult to do so. Unfortunately, hermeneutics was
    all that have been neglected in mathematics education. Meanwhile, only with hermeneutics, teaching
    and learning mathematics and also research in mathematics could flourish and be fruitful. Without it,
    it would be extremely hard for students to come up with a new creation in mathematics. This paper
    aims to shift the paradigm of mathematics education from learning (only) of mathematics into producing
    mathematics. Some examples are presented to illustrate the power of hermeneutics in developing
    mathematical imagination, ideas, and creativity towards mathematical discovery or invention.
  14. R.(III) P. Dioso
    ASM Science Journal, 2014;8(1):55-66.
    MyJurnal
    Through the six domains of the health-related quality of life (HRQOL) - physical, psychological, level of independence, social relationship, environment and spirituality or religion - ten out of one hundred randomly selected studies were analysed and evaluated as a theoretical outcome of self care using health products such as food supplements, multivitamins and minerals. A reconstructed HRQOL tool was used in the qualitative and the quantitative analysis and evaluation of the ten selected studies. A Critical Appraisal Skills Programme tool was also used in making sense of the evidences of the study trials. The Population, Intervention, Comparison and Outcome guide focused the protocol for the selection of the studies used in this meta-analysis. A probability sampling generated a uniform distribution of the populations. The manner of consuming or the route of administration, the volume and the preparation of commercially prepared health products were neither analysed nor evaluated as the exclusion criteria. Of the ten studies, nine gave a high significance to the six domains of the (O.R. = 90% / p =
  15. Ahmad Zaidee Laidin, Loganathan, P.
    ASM Science Journal, 2011;5(1):77-77.
    MyJurnal
    Awareness and sensitivity on the subject of green technology are currently commanding the attention of the world in the light of rising energy costs and the threat of global warming. Many countries are now recognizing the benefits of researching into and using green technology to reduce their carbon and water footprints and to minimize waste. (Copied from article).
  16. Ghazally Ismail
    ASM Science Journal, 2011;5(1):73-74.
    MyJurnal
    Human activity has ‘very likely’ been the primary cause of global warming since the start of the Industrial Revolution (18th–19th century). As a new player in industrial transformation, Malaysia can choose to ignore the warnings of global warming. blame. This may not augur well. Release of greenhouse gases have been categorically linked to climate change and global warming. In her march towards industrialization, Malaysia too has contributed to the release of greenhouse gases. Apart from those arising from natural sources, the industrial sector in Malaysia also releases other types of gases such as the fluorocarbons. This is evident from the worsening air quality in some of our cities. (Copied from article).
  17. Kumar Das, V.G.
    ASM Science Journal, 2013;7(2):173-220.
    MyJurnal
    Malaysia is currently poised to introduce its Science, Technology and Innovation (STI) Policy and Act to bolster the nation's efforts at economic and social transformation. In championing this initiative, the Academy of Sciences Malaysia, while continuing to advise the Government on STI issues of the day, has made major strides in taking stock of the country's STI strengths in the various sectors of the economy as well as weaknesses that need to be addressed in terms of human capital development. In this article, the author examines the level of research expertise presently in the country in the field of chemistry, and elaborates on the four key areas of energy, catalysis and chemical synthesis, materials science and biological chemistry which will be researched globally in the next few decades that we would also need to be engaged upon to remain competitive. Intended for a wider audience than chemists alone, the descriptive sections in the article by and large belie an interdisciplinary flavour. The article also advocates the need for a more thorough road mapping exercise of the STI efforts in chemistry across the spectrum of academia and industry and makes some recommendations towards forging strong collaborations in research between the universities, public research institutes and the industry which are seen as vital in providing cross-cutting chemical solutions throughout the value chains and to the success of technologies identified as critical to the nation.
  18. Sharif, J.M., Latiff, M.S.A., Ngadi, M.A.
    ASM Science Journal, 2007;1(2):109-128.
    MyJurnal
    Spatio-temporal datasets are a collection of datasets where data can vary in both space and time. Theoretically, such datasets can be considered as continuous and discrete. For example, specification of the function, F: Ed  T Rn, where Ed denotes d-dimensional Euclidean space, T = R* ∩ {} the domain of time and Rn an n-dimensional scalar field. Examples of such data sets include time-varying simulation results, film and videos, time-varying medical datasets, geometry models with motion or deformation, meteorological measurements, and many more. It is therefore highly desirable to use visualisation to summarize meaningful information in higher dimensional spatio-temporal datasets. Our aim is to conceive an efficient visual study to facilitate scientists in identifying temporal association among complex and chaotic atom movements in ion trajectories. An application that uses a streamline for spatial motion of ion trajectories and Colour Number Coding Scheme for temporal encoding of high degree of timeline events among mobile ions is proposed. With an anthology of the visual examples, it was revealed that this application would be beneficial for scientists to visually mine any 3D spatio-temporal dataset.
  19. Fauzi, R., Salazar, D.M., Kadzim, R.M., Hussin, A., Burbano, L.
    ASM Science Journal, 2009;3(2):161-167.
    MyJurnal
    In this project, a Geographic Information System (GIS) was used to collect and compile various field data in the Pedro Vicente Maldonado Ecuadorian Scientific Station Antarctica Base area. The main source of data was obtained from a global positioning system (GPS) survey using kinematic GPS (GPS-RTK) which allowed continuous point mapping in the terrain. GPS units were utilized in the collection of spatial data for all field work. The co-ordinates obtained were used to produce a point map which was then exported into GIS software where the proximity of cartographic phenomena and boundaries were mapped. All the collected data were subsequently gathered to develop the GIS database which was then used to generate and compile different maps to test for spatial and temporal relationships. The output of the project comprises a GIS database, spatial maps and 3D terrain model of the area. The developed GIS database can be used with other ecological datasets to provide biogeographical information, potential range distribution and sampling adequacy. The database is also applicable to geographical management and multi-disciplinary research projects.
  20. Marghany, M., Cracknell, A.P., Hashim, M.
    ASM Science Journal, 2009;3(1):7-16.
    MyJurnal
    This paper introduces a method for modification of the formula of the fractal box counting dimension. The method is based on the utilization of the probability distribution formula in the fractal box count. The purpose of this method is to use it for the discrimination of oil spill areas from the surrounding features e.g. sea surface and look-alikes in RADARSAT-1 SAR data. The result showed that the new formula of the fractal box counting dimension was able to discriminate between oil spills and look-alike areas. The low wind area had the highest fractal dimension peak of 2.9, as compared to the oil slick and the surrounding rough sea. The maximum error standard deviation of the low wind area was 0.68 which performed with a 2.9 fractal dimension value.
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