Browse publications by year: 2017

  1. Wan Nur Syuhaila Mat Desa, Dzulkiflee Ismail
    Sains Malaysiana, 2017;46:149-156.
    Impurity profiling of drug seizures is a scientific approach employed to understand drug trafficking networks thus has
    becoming increasingly important in criminal investigation. This paper presents the feasibility of using the Collaborative
    Harmonisation of Methods for the Profiling of AmphetamineType Stimulants (CHAMP) established by the European
    Commission authority for impurity profiling of amphetamine and methamphetamine samples. Both drugs were analysed
    using similar extraction procedure and analytical conditions. The impurities were extracted from an alkaline buffer
    solution (pH8.1) using toluene prior to gas chromatography-mass spectrometry (GC-MS) analyses. The results showed
    that the reproducibility of the method for detecting amphetamine and methamphetamine ranged between 7.4-8.9 and
    6.2-8.4 %RSD, respectively. Identification of impurities was performed by referencing against the available MS databases
    as well as to previous reported impurity profiling studies. Phenyl-2-propanone (P2P), also known as benzyl-methylketone
    (BMK), as well as other specific impurities such as 4-methyl-5-phenylpyrimidine, bis-(1-phynelisopropyl) amine,
    N-formylamphetamine and N,N-di (b-phenylisopropyl) amines were identified in the amphetamine samples, indicating
    Leuckart’s pathway as the route of synthesis. Because P2P was also detected in the methamphetamine samples, the
    possible route of synthesis of the methamphetamine samples being Leuckart’s, nitrostyrene synthesis or reductive
    amination could not be ruled out.
  2. Herdawatie Abdul Kadir, Mohd Rizal Arshad
    Sains Malaysiana, 2017;46:129-137.
    This paper suggests the wireless communication technique used to determine the information of blimp localization
    (distance and orientation) via wireless sensor network (WSN) protocol. In cooperative decentralized system, information
    exchanges between the agents are crucial. Each agent is required to share data to enable individual decision making
    task. In this work, the WSN were used as the data communications protocol which provides robust communication using
    the mesh networking. In order to support the multi agent communication network, the reliability of data needs to be
    proved. The performances of the communication selection were studied through experimental and simulation approach.
    The experimental results showed that the RSSI value from the device provided good statically data fit using the R-square
    with value of 0.947. This paper also proposed a new mobile node arrangement with hexagonal anchor node arrangement
    based on water particles formation. The node arrangement was simulated using the Senelex™ and showed low absolute
    error position thus achieving the desired cooperative system requirement.
  3. Yi Peng T, Mashitah Mat Don, Salmiah Ujang
    Sains Malaysiana, 2017;46:123-128.
    Rubberwood is the most popular timber for furniture manufacturing industry in Malaysia. Major drawback concerned
    that rubberwood is very prone to attack by fungi and wood borers, and the preservation method using boron compounds
    exhibited hazardous effect to the workers. Fungal-based biological control agents have gained wide acceptance and
    Schizophyllum commune secondary metabolite played an important role in term of antifungal agent productivity. The
    effects of initial pH, incubation temperature and agitation on biomass production by S. commune were investigated
    under submerged shake culture. In this work, it was found that the synthetic medium with initial solution pH of 6.5
    and incubated at 30ºC with shaking at 150 rpm provided the highest biomass production. The biomass extract from
    S. commune was then applied onto the rubberwood block panel to investigate its effectiveness. The results showed
    that biomass extract at a concentration of 5 µg/µL could inhibit the growth of selected rubberwood-degrading fungi,
    such as Lentinus sp., L. strigosus and Pycnoporus sanguineus.
  4. Inam Ali Shah, Sultan Mehmod Wazir, Rahmat Ali Khan
    Sains Malaysiana, 2017;46:117-122.
    Effects of different doses of fertilizers on growth and yield components of biodiesel plant (Jatropha curcas L.), was
    made in the prevailing environment of University of Science and Technology Bannu. The experiment was carried out in
    randomized complete block design (RCBD) with three replications. Nitrogen, phosphorus and potassium were applied
    in the form of urea, single super phosphate and potash in the shape of combined NPK, respectively, during sprouting
    of leaves and thereafter with each irrigation in split doses. The analysis of variance for number of branches per plant
    showed significant results indicated in ANOVA. Significantly the number of primary branches per plant 8.07 was recorded
    in T4 with the application of dose of (N P K: 2507.5 gm: 1091.5 gm: 501.5 gm). Maximum No. of secondary branches
    per plant (9.100) were recorded in T1 especially at both plots. Flower per inflorescence showed that maximum value
    (122.810) was recorded in T5 of especially at both plots. Inflorescence plant-1 showed that maximum value (39.477) were
    recorded in T1 and minimum value were noted as (12.733) at T3 on both the flats. The data for fruits per plant showed
    that maximum value (143.300) was recorded in T1. The seed index, which was the output of the aim of this research work,
    reflects highly significant differences in mean value observed for both subplots. Mean values showed that maximum seeds
    weight 45.86 was recorded in T1 of especially at both plots while low seed index was noted as 22.84 at T5 (N: 3400 gm,
    P: 1480 gm, K: 680 gm) at both the subplots.
    MeSH terms: Analysis of Variance; Fertilizers; Fruit; Nerve Tissue Proteins; Nitrogen; Phosphates; Phosphorus; Potassium; Seeds; Urea; RNA-Binding Proteins; Jatropha; Flowers; Inflorescence; Biofuels
  5. Mohammed Yahya Abdo, Wan Yaacob Wan Ahmad, Laily Bin Din, Nazlina Ibrahim
    Sains Malaysiana, 2017;46:83-89.
    A phytochemical study was conducted on the stems and leaves of Hedychium malayanum (Zingiberaceae). Three steroids
    namely stigmasterol (1), sitostenone (2) and stigmast-4-ene-3,6-dione (3) as well as one triterpene, lupenone (4) and
    one oxygenated sesquiterpene, caryophyllene oxide (5) were successfully isolated from the respective stems and leaves,
    utilizing several chromatographic techniques. Their structures were elucidated by spectroscopic means (IR, MS, NMR),
    and by comparison with the literature data.
    MeSH terms: Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Oxygen; Sesquiterpenes; Stigmasterol; Triterpenes; Zingiberaceae
  6. Nur Hartini Mohd Taib, Wan Ahmad Kamil Wan Abdullah, Ibrahim Lutfi Shuaib, Enrico M, Suzana Mat Isa
    Sains Malaysiana, 2017;46:67-74.
    Optimum combination of voxel size resolution and b-value for whole brain imaging has been determined. Data images
    were acquired using a 1.5T magnetic resonance imaging (MRI) system (GE Signa HDxt). Diffusion tensor imaging (DTI)
    scan was performed on phantom and a human volunteer. Six protocols which consist of various combination of voxel
    size and b-value were evaluated. Measurement of signal-to-noise ratio (SNR) and DTI parameter indices were carried out
    for both phantom and in-vivo studies. Due consideration was given to a combination of parameters yielding sufficient
    SNR with DTI values comparable to those obtained from previous reported studies. For the phantom study, SNR ≥ 20 was
    found in all of the protocols except for a combination of voxel size of 2.0 × 2.0 × 2.0 mm3
    with b-value of 1200 s/mm2
    (V2.0 B1200) and that of voxel size of 2.0 × 2.0 × 2.0 mm3
    with b-value of 1000 s/mm2
    (V2.0 B1000). For in-vivo study,
    all protocols presented SNR > 20. It was found that a combination of voxel size of 2.5 × 2.5 × 2.5 mm3
    with b-value of
    1000 s/mm2
    (V2.5 B1000) and that of voxel size of 2.5 × 2.5 × 2.5 mm3
    with b-value of 700 s/mm2
    (V2.5 B700) displayed
    the most comparable ADC and FA values with references. In terms of anatomic coverage, V2.5 B700 was found better
    than V2.5 B1000 as it assures coverage of the whole brain. In conclusion, a combination of voxel size of 2.5 × 2.5 × 2.5
    mm3
    with b-value of 700 s/mm2
    was considered as optimum parameters for brain DTI.
  7. Misro M, Ramli A, Ali J
    Sains Malaysiana, 2017;46:825-831.
    The fifth degree of trigonometric Bézier curve called quintic with two shapes parameter is presented in this paper. Shape parameters provide more control on the shape of the curve compared to the ordinary Bézier curve. This technique is one of the crucial parts in constructing curves and surfaces because the presence of shape parameters will allow the curve to be more flexible without changing its control points. Furthermore, by changing the value of shape parameters, the curve still preserves its geometrical features thus makes it more convenient rather than altering the control points. But, to interpolate curves from one point to another or surface patches, we need to satisfy certain continuity constraints to ensure the smoothness not just parametrically but also geometrically
  8. Nor Aziawati Azahari, Sarani Zakaria, Hatika Kaco, Sin Yee Gan, Chia Chin Hua, Sharifah Nabihah Syed Jaafar, et al.
    Sains Malaysiana, 2017;46:795-801.
    Membran selulosa terjana semula (MS) daripada pulpa teras kenaf telah berjaya dihasilkan menggunakan kaedah pra penyejukan dan digumpal menggunakan larutan asid sulfurik. MS disediakan daripada pelarutan selulosa kenaf dalam larutan akues NaOH/urea dan larutan selulosa seterusnya digumpal dengan H2SO4 pada kepekatan 5-12 peratus berat (% bt.) selama 1-10 min. Pengaruh kepekatan penggumpal H2SO4 dan masa penggumpalan ke atas struktur, saiz liang, sifat mekanik dan ketelusan cahaya MS telah dikaji menggunakan pembelauan sinar-X (XRD), imbasan mikroskop elektron tekanan boleh ubah (VPSEM), penguji regangan dan spektrofotometer ultra-violet sinar tampak (UV-vis). Keputusan VPSEM menunjukkan perubahan saiz liang membran bergantung kepada kepekatan larutan penggumpal H2SO4, manakala masa penggumpalan tidak mempengaruhi saiz liang membran. Membran yang direndam dengan larutan penggumpal pada kepekatan 10 % bt. dan masa pembekuan yang sederhana iaitu 5 min menunjukkan sifat mekanik yang lebih baik dengan nilai kekuatan regangan masing-masing 41.9 dan 43.5 MPa. Oleh itu, kajian ini dapat memberikan maklumat mengenai penyediaan MS dengan pelbagai saiz liang dan sifat mekanik dengan pengubahsuaian kepekatan dan masa penggumpalan.
    MeSH terms: Ataxia Telangiectasia; Methylglycosides; Urea; Hibiscus
  9. Awang R, Aziz N, Purhanudin N, Zalita Z
    Sains Malaysiana, 2017;46:509-514.
    In this work, amorphous carbon nitride (a-CNx
    ) thin films were deposited by radio frequency (RF) plasma enhanced
    chemical vapor deposition (RF-PECVD) technique. The RF power and gas mixture of methane (CH4
    ) and nitrogen (N2
    )
    flow was kept constant, while the electrode distance was varied from 1 to 6 cm. The effect of electrode distance on the
    chemical bonding, morphology and humidity sensing responses of the films were investigated. Fourier transform infrared
    spectroscopy (FTIR) studies showed a systematic change in the spectra and showed three main peaks namely the G
    and D-peak, C≡N triple bonds and C-H/O-H groups. Uniform and porous morphology was observed for films deposited
    at smallest distance followed by non-porous cubicle-like grain as electrode distance increased. Subsequently formation
    of vertically aligned nanostructures apparent both from its surface and cross section images by increasing of electrode
    distance to the fullest. The humidity sensing property has been studied by recording their resistance response to relative
    humidity (RH) at room temperature. It was found that the resistance value decreases from 15.4 to 3.6 kΩ with the increase
    in RH from 9 to 85%, with the highest sensitivity of 77% for film deposited at smallest distance of 1 cm.
  10. Raja Nor Suhaila, Sabreena Safuan
    Sains Malaysiana, 2017;46:463-468.
    Human umbilical vein endothelial cell (HUVEC) isolated from umbilical cord is widely used as endothelial cell model.
    However, HUVEC has been characteristically hard to maintain and showed molecular heterogeneity depending on the
    umbilical cord donors. Commercial HUVEC is commonly derived from European and Caucasian population which have
    different molecular characteristics from Asian women. This study aimed to optimize the isolation and culture condition of
    HUVEC using combinations of growth factors and extracellular matrix components so that the isolated HUVEC will purely
    represent the population under study. Umbilical cords were obtained from women post-labour. Different incubation times
    and digestive enzymes were used during endothelial cells isolation process. The culture conditions were optimized based
    on the coating materials and the media supplements. The results showed that 0.1% collagenase for 40 min incubation
    was the optimal isolation condition of HUVEC. HUVEC grown in 0.2% gelatin coated plate with 10% heat-inactivated
    fetal calf serum showed higher proliferative capacity and reduced cell death compared to other conditions (p<0.05). The
    results generated from this study provide a basic protocol of HUVEC isolation and culture conditions in order to generate
    working endothelial cell populations purely represent the Malaysian population.
    MeSH terms: Cell Separation; Extracellular Matrix; Female; Gelatin; Hot Temperature; Humans; Umbilical Cord; Umbilical Veins; Cell Death; Collagenases; Human Umbilical Vein Endothelial Cells
  11. Koo YP, Noorfatimah Yahaya, Wan Adnan Wan Omar
    Sains Malaysiana, 2017;46:449-455.
    Increasing demands for stingless bee honey in Malaysia have prompted alternative method using plastic cups as artificial
    honey pots within beehives to enhance yield. However, honey’s acidity may lead to migration of plastic additives, affecting
    body’s physiological responses on prolonged consumption. This study was performed to determine the presence of dibutyl
    phthalate (DBP) and oleamide in stingless bee honey collected from plastic cups. A method for simultaneous extraction
    and detection of both analytes by solvent terminated dispersive liquid-liquid microextraction (ST-DLLME) coupled with high
    performance liquid chromatography (HPLC) was developed. Good linearity was observed with coefficient of determination
    R2
    ≥ 0.97 in the concentration range of 0.5-50 and 10-250 µg/g for DBP and oleamide, respectively. The limit of detection
    for DBP was 0.15 µg/g; while oleamide was 4 µg/g. The limit of quantitation for DBP and oleamide was 0.5 and 11 µg/g,
    respectively. DBP and oleamide were not detected in all the honey samples collected.
  12. Tan WC, Lim SJ, Wan Aida Wan Mustapha
    Sains Malaysiana, 2017;46:439-448.
    Dalam kajian ini, bakteria asid laktik (LAB) serta sebatian aroma ikan pekasam daripada spesies yang berbeza
    ditentukan. Persampelan ikan pekasam iaitu tilapia, loma, lampam, sepat dan gelama diperoleh daripada pembekal
    Perusahaan Ikan Pekasam Kiah di Kuala Kangsar, Perak. Penentuan spesies LAB dijalankan melalui kaedah pencairan
    bersiri, pengkulturan LAB, ujian katalase, ujian pewarnaan spora serta ujian pengesanan Gram bakteria dan morfologi.
    Pengesahan spesies LAB dijalankan melalui pengekstrakan asid deoksiribonukleik (DNA), amplifikasi dengan tindak
    balas rantaian polimerasi (PCR), analisis elektroforesis gel dan penjujukan DNA. Hasil jujukan DNA yang diperoleh
    dibandingkan dengan jujukan dalam pangkalan data GenBank di NCBI menggunakan BLAST. Didapati Lactobacillus
    brevis KB290 DNA dan Lactobacillus casei W56 wujud dalam pekasam tilapia, Lactobacillus plantarum 16 dalam
    pekasam lampam, Lactobacillus casei BD-II kromosom dan Lactobacillus plantarum WCFS1 dalam pekasam sepat,
    Corynebacterium vitaeruminis DSM 20294 dan Streptococcus anginosus C1051 dalam pekasam gelama. Manakala
    Staphylococcus carnosus subsp. carnosus TM300 kromosom adalah LAB dominan dalam pekasam loma. Sementara
    itu, sebatian aroma ditentukan melalui kaedah pengekstrakan cecair menggunakan pelarut metanol dan heksana.
    Pemprofilan sebatian aroma dijalankan dengan kromatografi gas-spektometer jisim (GC-MS). Sebatian aroma dalam
    ekstrak metanol dan heksana daripada lima jenis ikan pekasam dibandingkan. Bilangan sebatian aroma yang diekstrak
    menggunakan metanol adalah lebih banyak berbanding dengan yang menggunakan heksana. Sebatian aroma yang
    paling banyak dikesan adalah daripada pekasam loma. Asid karboksilik merupakan sebatian yang paling dominan
    dalam ikan pekasam dan memberi bau hamis serta tengik.
    MeSH terms: Animals; Color; Corynebacterium; DNA; Lactobacillus casei; Gas Chromatography-Mass Spectrometry; Staphylococcus; Polymerase Chain Reaction; Tilapia; Databases, Nucleic Acid; Streptococcus anginosus; Lactobacillus plantarum; Loma
  13. Amirah Audadi Madzen, Lam KC
    Sains Malaysiana, 2017;46:421-428.
    Fenologi tumbuhan menggambarkan fasa kitaran hidup atau aktiviti tumbuhan dan adalah penting untuk memahami
    interaksinya dengan iklim. Kajian dilakukan untuk mengenal pasti respons fenologi tumbuhan dan metrik fenologi
    hutan dipterokarpa, kelapa sawit dan pokok getah menggunakan data indeks tumbuhan Enhanced Vegetation Index
    (EVI) daripada MODIS-Aqua (produk MYD13Q1) dan purata hujan bulanan sepanjang tahun 2007 dan 2009 di negeri
    Johor. Pola hujan pada tahun 2007 menunjukkan taburan hujan normal, manakala tahun 2009 mengalami kekurangan
    hujan sepanjang tempoh sebelas tahun (2000-2010). Hasil mendapati tren EVI hutan dipterokarpa lebih bervariasi pada
    2009 dengan nilai EVI antara 0.39-0.64 berbanding tren pada 2007 yang tekal dengan nilai EVI antara 0.33-0.57. Tren
    fenologi kelapa sawit pada 2007 lebih kerap mengalami turun naik berbanding pada 2009, masing-masing dengan EVI
    antara 0.45-0.71 dan 0.5-0.74. Corak fenologi pokok getah pada kedua-dua tahun kajian adalah sama dan julat EVI
    pada 2009 adalah lebih kecil berbanding 2007, masing-masing dengan EVI antara 0.39-0.62 dan 0.30-0.73. Pengaruh
    masa susulan ke atas tahap kehijauan tumbuhan telah dikesan, khususnya selepas peristiwa hujan lebat dalam dua
    tahun tersebut dan sedikit sebanyak mempengaruhi nilai korelasi antara pemboleh ubah purata hujan bulanan dengan
    EVI tumbuh-tumbuhan. Permulaan dan pengakhiran musim pertumbuhan hutan dipterokarpa bagi kedua-dua tahun
    berlaku dalam bulan yang sama, iaitu Februari (permulaan musim) dan Disember (pengakhiran musim). Tidak wujud
    perbezaan yang ketara antara panjang musim pertumbuhan kelapa sawit bagi kedua-dua tahun, iaitu hanya 32 hari
    lebih panjang pada 2007 berbanding 2009. Musim pertumbuhan pokok getah pula adalah lebih panjang pada 2007 dan
    lebih singkat pada 2009, masing-masing 176 hari dan 113 hari.
    MeSH terms: Ataxia Telangiectasia; Hydrocarbons, Chlorinated; Methylglycosides
  14. Md. Faisal Md. Basir, Uddin M, Md. Ismail A
    Sains Malaysiana, 2017;46:327-333.
    Induced magnetic field stagnation point flow for unsteady two-dimensional laminar forced convection of water based nanofluid containing microorganisms along a vertical plate has been investigated. We have incorporated zero mass flux boundary condition to get physically realistic results. The boundary layer equations with three independent variables are transformed into a system of ordinary differential equations by using appropriate similarity transformations. The derived equations are then solved numerically by using Maple which use the fourth-fifth order Runge-Kutta-Fehlberg algorithm to solve the system of similarity differential equations. The effects of the governing parameters on the dimensionless velocity, induced magnetic field, temperature, nanoparticle volume fraction, density of motile microorganisms, skin friction coefficient, local Nusselt number and motile density of microorganisms transfer rate are illustrated graphically and tabular form. It is found that the controlling parameters strongly affect the fluid flow and heat transfer characteristics. We compare our numerical results with published results for some limiting cases and found excellent agreement.
    MeSH terms: Algorithms; Hot Temperature; Temperature; Water; Friction; Convection; Acer; Nanoparticles; Physical Phenomena; Magnetic Fields
  15. Siti Atiqah Ishak, Iskandar Shahrim, Siti KAR, Azhar A. Alrahman
    Sains Malaysiana, 2017;46:303-308.
    The aim of this study was to evaluate properties of normoxic polymer gel 2-Hydroxyethyl methacrylate monomer (HEMAG)
    as a point dosimeter by using optical properties evaluation techniques. HEMAG were prepared from seven different
    radiation dose within five different depths of HEMAG dosimeters. These HEMAG dosimeters were irradiated by linear
    accelerator with 6 MV photon beams. The absorption spectra were measured by using a UV-visible spectrophotometer in
    the wavelength range from 300 to 800 nm. Then, the data was analysed to determine the optical energy band gap (Eg
    )
    and Urbach’s energy (∆E). The result showed that Eg
    and ∆E were dependent on radiation dose and percentage of depth
    dose (PDD). In additional, Eg
    with indirect transition of HEMAG decreased as radiation dose increased and increased
    with traversing of depth. ∆E of HEMAG increased as the dose increased and decreased with traversing depth of monomer.
    There was a shift in the Eg
    values towards lower energy as the dose increased and led to a shift of the ∆E value towards
    the higher energy with increasing dose. This observation supported the increase of structured disorder of the polymer
    with increasing radiation dose, which resulted in the lower energy transitions that was feasible and reduced the values
    of Eg
    . In conclusion, HEMAG has a potential to be used as a dosimeter at low radiation dose in the clinical radiotherapy
  16. Uthumporn U, Nadiah I, Izzuddin I, Cheng LH, Aida H
    Sains Malaysiana, 2017;46:223-229.
    This research mainly focused on isolation of non-starch polysaccharide (NSP) from different parts of cassava tuber by using water extraction and to evaluate the effect of NSP addition into flour on nutritional composition, swelling and solubility, pasting properties and dough characteristics by farinograph and extensograph. Three origins of (NSP) extracted were used: cassava peels, coarse and fine portions from cassava flesh. The isolation of NSP was done by using water extraction method and designated as water-extractable (WEP) and water un-extractable non starch polysaccharides (WUP). The percentage yield of WEP (0.24 - 1.64%) from water extraction was significantly lower as compared to WUP (2.58 - 4.33%). Upon the incorporation of 5% NSP, the cassava flour showed lower moisture content compared to the sample without the addition of NSP, while fats and crude fiber content of cassava flours were found to be increased upon the incorporation of 5% NSP from all origins. Swelling power and solubility of cassava flour were being reduced upon the incorporation of 5% of NSP from cassava peel and coarse portion of cassava flesh. The changes in dough characteristics showed that water absorption of the samples upon the addition of 5% NSP into wheat flour was found to be higher compared to control wheat flour. In contrast, dough stability and extensibility, tolerance index, resistance to extension, as well as the work input necessary for dough deformation from wheat flour with addition of 5% NSP resulted lower than control wheat flour. Overall, NSP extracted from cassava peels and coarse portion of cassava flesh performed similar characteristics and functional properties upon the incorporation into the flour.
    MeSH terms: Manihot; Fats; Flour; Polysaccharides; Solubility; Water; Triticum; Plant Tubers; Physical Phenomena
  17. Nazatul Syadia Zainordin, Nor Azam Ramli, Maher Elbayoumi
    Sains Malaysiana, 2017;46:197-207.
    ir quality has deteriorated in urban areas as a result of increased anthropogenic activities. Quantitative information on the influence of meteorological conditions on several pollutants in a tropical climate is still lacking. Real-time ozone (O3) and nitrogen dioxide (NO2) levels were measured nearby selected schools in Malaysia to examine the impact of meteorological factors on monitoring pollutants. The results showed the overall 10 min average concentrations of the main parameters during school holiday were 24 ppb (O3) and 33 ppb (NO2) while during school day the overall 10 min average concentrations were 26 ppb (O3) and 51 ppb (NO2). Although there are no minimum requirements for short-term exposure by MAAQG, if compared to 1 h average requirements, all concentrations were still below the suggested values. Regarding spatial distribution, a different trend in pollutant concentration among the schools was observed because of the influence of temperature (AT) and wind speed (WS). The results were verified by Pearson correlation, where significant correlations (p<0.01) were determined between air pollutants and meteorological factors, which were temperature, wind speed and relative humidity. Meanwhile, the distribution of O3 was moderately correlated with NO2. However, the results of multivariate analysis indicate that temperature and relative humidity had the most significant influence on the formation of O3. In summary, the results of this study showed that all precursors and meteorological parameters contribute to the production of O3. Hence, reducing O3 precursors, which are emitted by vehicles, is essential to lessening the exposure to O3
    MeSH terms: Air Pollutants; Holidays; Humidity; Malaysia; Meteorological Concepts; Nitrogen Dioxide; Ozone; Temperature; Tropical Climate; Wind; Multivariate Analysis; Meteorology
  18. Amirul-aiman A, Noraini T, Nurul-aini C
    Sains Malaysiana, 2017;46:1679-1685.
    Acanthaceae merupakan famili tumbuhan angiosperma di bawah order Lamiales yang terdiri daripada sekurang-kurangnya 4000 spesies sama ada spesies tropika atau subtropika. Spesies daripada famili ini ditemui di pelbagai habitat dan mempunyai pelbagai morfologi serta corak taburan geografi. Walau bagaimanapun, maklumat mengenai ciri anatomi bagi Acanthaceae masih dangkal sehingga ke hari ini. Objektif kajian ini ialah untuk mengenal pasti jenis trikom yang hadir pada permukaan epidermis adaksial dan abaksial sepal dan juga petal bunga bagi beberapa spesies terpilih daripada Acanthaceae di Semenanjung Malaysia. Kajian ini melibatkan pengumpulan sampel di lapangan, penyediaan spesimen baucer, teknik kajian epidermis petal, cerapan di bawah mikroskop cahaya dan juga cerapan di bawah mikroskop imbasan elektron. Tiga puluh jenis trikom dicerap dalam kajian ini dan daripada jumlah tersebut, 23 jenis trikom dicerap hadir pada permukaan epidermis petal manakala 17 jenis trikom dicerap hadir pada permukaan epidermis sepal. Jenis trikom yang direkodkan ialah trikom ringkas unisel dan ringkas multisel, trikom kelenjar kapitat dan kelenjar peltat serta juga trikom berlengan. Keputusan kajian ini menunjukkan kehadiran dan jenis trikom pada permukaan sepal dan petal mempunyai nilai taksonomi yang berguna untuk tujuan pembezaan dan pengecaman spesies. Maklumat ciri morfologi trikom yang diperoleh daripada kajian ini merupakan maklumat baharu ciri anatomi bunga bagi Acanthaceae.
    MeSH terms: Lamiales; Animals; Epidermis; Malaysia; Ecosystem; Acanthaceae; Tetrahydroisoquinolines; Gastropoda
  19. Nurhayati Abdullah, Fauziah Sulaiman, Aminu Aliyu Safana
    Sains Malaysiana, 2017;46:2441-2445.
    The objective of this study was to produce briquette from the mixture of pyrolysis products. Palm shell was pyrolyzed at a temperature of 400°C for 2 h holding time and heating rate of 10°C/min. The biochar and bio-oil ratio was prepared at 3:1 weight percentages for briquette. The viscosity of bio-oil was improved to increase the bonding forces. The characterization of biochar, bio-oil, coal and briquette were analyzed and presented in this study. The density and compressive strength of briquette were, respectively, found to be 0.94 gcm-3 and 3.20 Nmm-2. The shatter and water resistance of briquette were established to be 97 and 96 wt. %, respectively. The high heating value (HHV) of briquette was 29.6 MJkg-1 greater than that of Malaysian sub-bituminous coal 24.6 MJkg-1. It implies that the briquette produced is stable, durable and qualitative. Therefore, it can be concluded that the briquette can substitute coal in some applications.
  20. Noraini T, Amirul Aiman A, Mohd Arrabe A, Nurul Aini C
    Sains Malaysiana, 2017;46:2291-2303.
    Famili Rhizophoraceae ialah famili tumbuhan utama di hutan paya bakau dengan 16 genus dan 120 spesies dan di Semenanjung Malaysia terdapat tujuh genus dan 17 spesies. Kajian palinologi masih kurang dijalankan di hutan paya bakau untuk melihat kepentingan ciri morfologi debunga dan adaptasinya terhadap persekitaran. Objektif kajian ini ialah untuk menyenaraikan ciri umum, variasi dan ciri diagnosis morfologi debunga antara spesies dan genus dalam famili Rhizophoraceae di Semenanjung Malaysia. Kaedah kajian melibatkan teknik asetolisis, pencerapan di bawah mikroskop cahaya dan mikroskop imbasan elektron. Keputusan kajian menunjukkan terdapat dua kelas debunga iaitu tri-zono-kolpat dan tri-zono-kolporat. Kesemua spesies kajian mempunyai debunga bersaiz kecil (10-25 μm) dan mempunyai debunga bentuk sferoid kecuali Rhizophora x lamarckiidengan bentuk subprolat. Dua corak hiasan eksin ditemui pada genus Bruguiera iaitu skabrat-perforat (B. cylindrica, B. parviflora. B. hainesii dan B. sexangula) dan psilat-skabrat (B. gymnorhiza). Genus Ceriops dan Rhizophora stylosa mempunyai hiasan eksin perforat manakalaR. apiculata dan R. mucronata mempunyai corak eksin perforat-retikulat. Kekunci dikotomi pengecaman spesies dan genus telah dibina berdasarkan keputusan kajian. Secara kesimpulan, ciri morfologi debunga mempunyai nilai taksonomi terutamanya untuk pembezaan dan pengecaman spesies dan genus bagi famili Rhizophoraceae.
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