Browse publications by year: 2016

  1. Mohd Jamil Abdul Wahab, Noor Azrieda Abd Rashid, Salmiah Ujang, Choon LS
    Sains Malaysiana, 2016;45:1139-1147.
    Timber scaffold boards have been widely utilised in the offshore construction industry. However, technical specifications
    and inspection procedure for the application of scaffold boards from a wood material were inadequate. In the development
    of the standard requirements, evaluation of actual engineering practices could indicate the level of workplace safety. A
    study was conducted to identify risk and safety measures concerning the use of timber scaffold boards in construction.
    This article discusses on the occupational risks and ergonomics issues of the scaffolding application based on the physical
    and mechanical conditions of tropical timber scaffold boards extracted from offshore oil and gas rigs. The boards were
    exposed to a seasonal climate of East Coast monsoon of South China Sea between November and February. The scaffolding
    application extended up to 20 m directly above the ocean surface and some boards were completely immersed below
    the ocean surface particularly during elevated tidal waves. Some of the boards were installed as the on-deck platforms.
    Forty scaffold boards fabricated from tropical timber species were evaluated. Physical characteristics of the boards
    were described by natural and man-made factors. A three-point bending test was conducted to determine the maximum
    load capacity of each board and the mode of fracture was evaluated. Timber identification test was conducted to identify
    the groups of the timber being used. The microscopic observation confirmed the presence of hyphae which indicated the
    biological deterioration has happened in some of the boards. Occupational risks were summarised based on the results
    of the physical and mechanical assessments
    MeSH terms: China; Climate; Engineering; Oceans and Seas; Physical Examination; Seasons; Wood; Workplace; Hyphae; Tidal Waves; Construction Industry
  2. Ramalingam A, Siti Balkis Budin, Lim Yc, Lislivia Si Yn, Satirah Zainalabidin
    Sains Malaysiana, 2016;45:1131-1137.
    UKMR-1, a local variant of mutant Roselle strain (Hibiscus sabdariffa) is enriched with free radical scavenging polyphenols
    such as anthocyanin, vitamin C and hydroxycitric acid. However, pharmacological actions of UKMR-1 are not fully known.
    This study was conducted to determine whether supplementation of aqueous UKMR-1 calyx extract was able to protect
    against nicotine-induced cardiac injury in rats. In this experimental study, healthy male albino rats were randomly
    allotted into three groups (n=7 per group): control, nicotine and UKMR-1+Nicotine groups. Nicotine (0.6 mg/kg, i.p.)
    was administered to both nicotine and UKMR-1+Nicotine groups for 28 consecutive days. UKMR-1+Nicotine group also
    received 100 mg/kg UKMR-1 extract orally via gavage 30 min prior to nicotine injection, daily. UKMR-1+Nicotine group
    had significantly (p<0.05) higher lactate dehydrogenase (LDH) activity, as well as lower malondialdehyde content in
    heart tissue homogenate than nicotine group, suggesting its cardio protective activity by inhibition of lipid peroxidation.
    UKMR-1 also lowered (p<0.05) the blood pressure in nicotine-administered rats. In addition, UKMR-1 significantly (p<0.05)
    restored activities of cytosolic superoxide dismutase, glutathione peroxidase and glutathione-S-transferase as well as
    redox balance ratio (GSH:GSSG). In conclusion, UKMR-1 was a
    MeSH terms: Animals; Anthocyanins; Ascorbic Acid; Blood Pressure; Blood Pressure Determination; Citrates; Free Radicals; Glutathione Peroxidase; Glutathione Transferase; Male; Malondialdehyde; Nicotine; Oxidation-Reduction; Superoxide Dismutase; Lipid Peroxidation; Glutathione Disulfide; Protective Agents; Hibiscus; Lactate Dehydrogenases; Rats; Polyphenols
  3. Aqilah Leela T. Narayanan, Muhammad Akmal Ayob, Norayati Nordin, Arief Ruhullah A. Harris, Eko Supriyanto
    Sains Malaysiana, 2016;45:1121-1129.
    Lung atelectasis caused by shallow breathing patterns is common after cardiac, thoracic and upper abdominal surgeries.
    A common method used to address this problem is to encourage patients to perform breathing exercises using incentive
    spirometers in the postoperative period. However, to be effective, this procedure must be repeated regularly so that
    adequate lung volumes can be maintained to prevent atelectasis. Current models of single-use, low-cost incentive
    spirometers do not have features that can track and store data on breathing exercises. This makes it difficult to monitor
    patients’ breathing exercises effectively. We present here a device designed to be interfaced with the Spiro-ball incentive
    spirometer and programmed to monitor the incentive spirometry performance. Laboratory based validation performed
    indicate that there were no significant differences between the value obtained from the device and manual reading;
    p-value > 0.05 and root-mean-square error (RMSE) is 3.882. The device was able to retrieve and display pertinent data
    on incentive spirometry performance. It was also able to correctly track and register random sets of inspiration data
    through different dates and timelines. Being a separate entity which is reusable, it does not add to the cost of the singleuse
    incentive spirometer
  4. Fazia Adyani Ahmad Fuad, Houston Douglas R, Michels Paul AM, Fothergill-gilmore Linda A, Walkinshaw Malcolm D
    Sains Malaysiana, 2016;45:1113-1120.
    Cofactor-independent phosphoglycerate mutase has been proposed as a therapeutic target for the treatment of
    trypanosomatid diseases. In this paper, we report the identification of compounds that could potentially be developed as
    selective inhibitors of cofactor-independent phosphoglycerate mutase from Leishmania mexicana (LmiPGAM). Virtual
    screening was used in this search, as well as compounds identified by high-throughput screening. A ligand-based virtual
    screen programme, ultra fast shape recognition with atom types (UFSRAT), was used to screen for compounds resembling
    the substrate/product, before a structure-based approach was applied using AutoDock 4 and AutoDock Vina in a consensus
    docking scheme. In this way eight selected compounds were identified. In addition, three compounds from the Library of
    Pharmacologically Active Compounds (LOPAC) were selected from the published results of high-throughput screening of
    this library. The inhibitory effects of these compounds were tested at a fixed concentration of 1 mM. The results showed
    that seven compounds inhibited LmiPGAM activity and of these, two compounds (one each from high-throughput and
    virtual screening) showed substantial inhibition (i.e. 14% and 49% remaining activity, respectively). Taken together, the
    findings from this study indicate that these compounds have potential as novel inhibitors that specifically target LmiPGAM.
    MeSH terms: Inorganic Chemicals; Leishmania mexicana; Libraries; Ligands; Phosphoglycerate Mutase; Gene Library; Consensus
  5. Kim TW, Kim CW, Kwon SG, Hwang JH, Park DH, Kang DG, et al.
    Sains Malaysiana, 2016;45:1097-1103.
    In order to examine differences of meat quality traits depending on pH values post-mortem, the pH range was classified
    according to initial pH (pH45min) and ultimate pH (pH24hr) post-mortem. The differences of meat quality traits depending
    on sex were not changed by a number of amount, except for backfat thickness and fat content. The value of pH45min was
    positively correlated with pHdif, whereas pH24hr was negatively associated with lightness (CIE L*) and protein content. At
    pH45min post-slaughter, collagen content, fat content, shear force, water holding capacity and yellowness (CIE b*) showed
    lower values at the higher pH range of pH>6.7 than those of other ranges, but CIE L* and redness (CIE a*) presented
    the lowest value at the intermediate pH range of pH6.3~6.7. Conversely, at pH24hr post-slaughter, fat and moisture
    contents maintained the highest average values at the higher pH range of pH>6.1, but protein content showed higher
    value at the lower pH range of pH<5.7. Higher pH24hr appeared significantly lower shear force, but higher water holding
    capacity. CIE L*, a*, and b* values showed significantly higher values at the lowest region of pH24hr. Since meat quality
    characteristics seemed to be favored by consumers in rather than at the range of pH5.7~6.1, which showed significant
    differences of meat color, appearance, and meat juiciness, it is suggested that production of pork meat to appropriate
    pH value is performed by pig breeders and control measures taken during pre- and post-slaughters.
    MeSH terms: Red Meat; Animals; Collagen; Color; Meat; Swine; Water; Sus scrofa
  6. Nurul Ashikeen Ab Razak, Mustafa Abdul Rahman, Tuen AA
    Sains Malaysiana, 2016;45:1089-1095.
    Family Scolopacidae includes the sandpipers, shanks, snipes, godwits and curlews. Systematic classifications of shorebirds
    at the higher level have been successfully resolved. Nevertheless, the phylogeny of shorebirds in the familial level is still
    poorly understood. Thus, this phylogenetic study on Scolopacidae was conducted upon the framework provided by the first
    sequence-based species-level phylogeny within the shorebirds to determine the phylogenetic relationships among family
    members of Scolopacidae in West Borneo, Sarawak using combined gene markers, mtDNA Cytochrome Oxidise I (COI)
    and nucDNA Recombinant Activating Gene 1 (RAG1). A total of 1,342 base pair (bp) were inferred from both COI and RAG1
    gene from 45 sequences constituted of 15 species Scolopacidae sampled from Sarawak namely Xenus cinereus, Actitis
    hypoleucos, Tringa totanus, Tringa glareola, Tringa stagnatilis, Heteroscelus brevipes, Calidris alba, Calidris ruficollis,
    Calidris ferruginea, Calidris tenuirostris, Calidris alpina, Gallinago stenura, Gallinago megala, Numenius arquata, and
    Numenius phaeopus. The phylogenetic tree was constructed with Charadrius mongulus derived as an outgroup. The
    Bayesian Inference (BI) tree constructed supported grouping of species into several lineages of Numeniinae, Calidrinae,
    Scolopacinae and Tringinae. The groupings of species into several lineages correlate with morphological features that
    contribute to their adaptation and ability of the species to fit to their ecosystems.
    MeSH terms: Animals; Base Sequence; Bayes Theorem; Borneo; Cytochromes; DNA, Mitochondrial; Malaysia; Phylogeny; Genes, RAG-1; Ecosystem; Base Pairing; Charadriiformes
  7. Chan Kg, Yap Ac, Choo Ym
    Sains Malaysiana, 2016;45:1073-1077.
    Burkholderia cenocepacia and Serratia marcescens are Gram-negative proteobacteria commonly found in the natural
    environment and are also opportunistic pathogens that caused a number of human diseases. The fermentation culture of
    Burkholderia cenocepacia yielded three compounds, 4-(2-hydroxyethoxy)-phenol (1), Maculosin (2) and methyl myristate
    (3). Compound 2 was also isolated together with cyclo(L-Leu-L-Pro) (4) from Serratia marcescens. Compound 1 was
    isolated from a natural source for the first time and the first isolation of compounds 2-4 was also reported from both
    Burkholderia cenocepacia and Serratia marcescens.
    MeSH terms: Environment; Fermentation; Humans; Myristates; Peptides, Cyclic; Phenols; Piperazines; Serratia marcescens; Phenol; Myristic Acid; Proteobacteria; Burkholderia cenocepacia
  8. Ling Onn M, Teen Lim P, Aazani Mujahid, Proksch P, Müller M
    Sains Malaysiana, 2016;45:1063-1071.
    Endophytic fungi provide protection to their host plant and the fungi often produce antimicrobial compounds to aid the host
    fighting off pathogens. These bioactive compounds were secondary metabolites which were often produced as waste- or
    by-products. In the present study, endophytic fungi isolated from mangrove plants and soils were characterized and their
    antimicrobial production and bioremediation potential of heavy metals copper (Cu) and zinc (Zn) were assessed. Twelve
    (12) isolated and identified endophytic fungi belonged to seven species; Penicillium, Curvularia, Diaporthe, Aspergillus,
    Guignardia, Neusartorya and Eupenicillium. Antimicrobial activities of these 12 fungal endophytes were tested against
    Gram negative bacteria; Bacillus subtilis, Staphylococcus aureus, Gram positive bacteria; Escherichia coli and fungi;
    Candida albicans and Aspergillus niger among others. Two isolates (related to Guignardia sp. and Neusartoya sp.) showed
    strong antimicrobial (and antifungal) activity whereas the rest showed no activity. Compounds were isolated from both
    isolates and screened using HPLC. Both isolates displayed chemically very interesting chromatograms as they possessed a
    high diversity of basic chemical structures and peaks over a wide range of polarities, with structures similar to Trimeric
    catechin and Helenalin among others. For bioremediation assessment, the results showed maximum biosorption capacity
    for two isolates related to Curvularia sp. and Neusartorya sp., with the former removing 25 mg Cu/g biomass and the
    latter removing 24 mg Zn/g biomass. Our results indicated the potential of mangrove endophytic fungi in producing
    bioactive compounds and also highlighted their potential for the treatment of heavy metal-contaminated wastewater.
    MeSH terms: Anti-Infective Agents; Anti-Bacterial Agents; Antifungal Agents; Aspergillus niger; Bacillus subtilis; Biodegradation, Environmental; Candida albicans; Catechin; Chromatography, High Pressure Liquid; Copper; Escherichia coli; Penicillium; Sesquiterpenes; Soil; Staphylococcus aureus; Zinc; Biomass; Eupenicillium; Endophytes; Waste Water
  9. Wan Haizatul Akmal Che Yusoff, Zazali Alias, Khanom Simarani
    Sains Malaysiana, 2016;45:1057-1062.
    The glutathione S-Transferase (GST) enzyme plays an important role in cellular detoxification. This multifunctional enzyme
    is involved in Phase II detoxification pathways that protect cellular macromolecules from being attacked by harmful
    compound. The study is an attempt to isolate glutathione transferase-expressing bacteria from the rhizospheric soil of
    selected herbal plants. Screening showed nine positive isolates out of twelve bacterial samples from a large microbial
    population in our soil collection. Crude extract from strain E1 which was isolated from Piper sarmentosum (Kadok)
    showed the highest specific activity against 1-chloro-2, 4-dinitrobenzene substrates (5.78 × 10-06 µmol/min/mg). Based
    on the carbon utilization of E1 assessed using Biolog system, the strain was identified as Comamonas testosterone E1.
    Glutathione S-transferase purification using GST trap yielded two distinct subunits with molecular weights of 23 and 24
    kDa as visualized on 1D SDS-polyacrylamide gel electrophoresis. The purified GST showed reactivity towards 1-chloro-2,
    4-dinitrobenzene, 1, 2-dichloro-4-nitrobenzene and ethacrynic acid with specific activity of 0.264 ± 0.038 nmol/min/
    mg and 0.056 ± 0.002 nmol/min/mg and 10.500 ± 3.130 nmol/min/mg, respectively. However, no activity was detected
    against p-Nitrobenzyl chloride, Sulfobromophthalein, trans-4-phenyl-3-butene-2-one, hexa-2, 4- dienal, trans-hepta-2,
    4-dienal and trans-oct-2-enal in the study.
  10. Ouled-haddar H, Sifour M, Idoui T, Bouridane H, Arid S
    Sains Malaysiana, 2016;45:1049-1055.
    A Lactobacillus plantarum strain G1 was previously isolated from chicken crop and it was found to show interesting
    probiotic properties. In this study, several microencapsulation combined materials were used to test their ability to protect
    cells from gastrointestinal harsh conditions. The results on kinetics of cell release after exposition to acidic pH (2.0)
    indicated that the efficiency of cell entrapment of the gels was as follows starting from the highest capacity to the lowest
    one: sodium alginate, alginate-agar (AA), alginate-starch (AS) and κ-carrageenan. In addition, effect of bile salts on
    cell release was also tested; the results showed that the efficiency of entrapment of the gels was different and as follows
    starting from the highest capacity to the lowest one: AA, sodium alginate, κ-carrageenan, and AS. Moreover, viability of
    free and alginate-microencapsulated Lactobacillus plantarum after exposure to acid, bile and pancreatic enzymes was
    investigated; the results showed that microencapsulation was capable of protecting cells against the harsh conditions of
    the gastrointestinal tract. In addition, microencapsulation enhanced the viability of Lb. plantarum during cold storage
    for 2 weeks and during a range of heat treatments.
  11. Jiang L, Yue K, Yang Y, Wu Q
    Sains Malaysiana, 2016;45:1041-1047.
    Litter decomposition is vital for carbon and nutrient turnover in terrestrial ecosystems, and this process has now
    been thoroughly demonstrated to be regulated by various mechanisms. The total environment has been continuously
    changing in recent decades, especially in high-latitude regions; these alterations, however, profoundly contribute to the
    decomposition process, but a comprehensive recognition has not available. Here we reviewed the empirical observations
    and current knowledge regarding how hydrological leaching and freeze-thaw events modulate early decomposition of
    plant litter. Leaching contributes a considerable percentage of mass loss and carbon and nutrient release in early stage of
    decomposition, but the magnitudes are different between species levels depending on the chemical traits. Frequent freezing
    and thawing events could positively influence decomposition rate in cold biomes but also hamper soil decomposer and
    there is no general and predictable pattern has been emerged. Further experiments should be manipulated to estimate
    how the altered freezing and thawing effect on carbon and nutrient release from plant litter to better understanding the
    changing environment on litter decomposition.
    MeSH terms: Carbon; Environment; Freezing; Plants; Soil; Ecosystem; Hydrology
  12. Norhayati Y, Wahizatul Afzan A, Siti Noor Jannah S, Nurul Wahidah MR
    Sains Malaysiana, 2016;45:1035-1040.
    Interaction between the Red Palm Weevil (RPW) and coconuts will stimulate the plants’ early response by producing the
    reactive oxygen species (ROS) which causes lipid peroxidation and membrane damage of the host plants. Thus, a multiple
    defense lines, including both scavenging enzymes and molecular antioxidants have been evolved to promptly inactivate
    these radicals. This study investigated the responses of catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX),
    α-tocopherol, ascorbic acid and carotenoids contents of three coconut cultivars which were PANDAN, MAWA and MATAG
    against the RPW infestation. The infested PANDAN and MAWA exhibited higher CAT, POD and APX specific activities of 2.60
    ± 0.11, 5.0 ± 0.72 and 1.58 ± 0.20 units/mg protein for PANDAN whereas 1.13 ± 0.04, 39.38 ± 2.29 and 1.15 ± 0.16 units/
    mg, protein for MAWA) compared with controls. However, MATAG cultivar showed no significant difference (p<0.05) in the
    production of both enzymes except for POD specific activities. RPW infestations only managed to trigger the α-tocopherol
    concentrations in the MAWA cultivar compared with the others. Infested MAWA and MATAG increased the ascorbic acid
    concentrations, however, a contrast results was observed in infested PANDAN. All coconut cultivars exhibited higher
    carotenoids content (2771.20 ± 263.90, 3043.20 ± 526.35 and 921.20 ± 281.10 µg/g.fwt of PANDAN, MAWA and MATAG,
    respectively) compared with their respective controls (455.20 ± 135.10, 1408.40 ± 103.02 and 248.80 ± 110.39 µg/g.
    fwt). The above results indicated that the oxidative stress induced by the RPW infestation would stimulate the activities of
    enzymes and molecular antioxidants studied especially in infested MAWA. Thus, it may be suggested that MAWA cultivar
    was more tolerance towards RPW infestation compared to MATAG and PANDAN. It is hoped that this finding will provide
    clues on how plant respond toward stress during infestation, thus further action can be activated as soon as possible to
    control the spread of R. ferrugineus.
  13. Razieh Shojanoori, Helmi Z.m. Shafri, Shattri Mansor, Mohd Hasmadi Ismail
    Sains Malaysiana, 2016;45:1025-1034.
    The growth of residential and commercial areas threatens vegetation and ecosystems. Thus, an urgent urban management
    issue involves determining the state and the quantity of urban tree species to protect the environment, as well as controlling
    their growth and decline. This study focused on the detection of urban tree species by considering three types of tree
    species, namely, Mesua ferrea L., Samanea saman, and Casuarina sumatrana. New rule sets were developed to detect these
    three species. In this regard, two pixel-based classification methods were applied and compared; namely, the method of
    maximum likelihood classification and support vector machines. These methods were then compared with object-based
    image analysis (OBIA) classification. OBIA was used to develop rule sets by extracting spatial, spectral, textural and color
    attributes, among others. Finally, the new rule sets were implemented into WorldView-2 imagery. The results indicated
    that the OBIA based on the rule sets displayed a significant potential to detect different tree species with high accuracy.
    MeSH terms: Biological Phenomena; Environment; Trees; Ecosystem; Protective Agents; Support Vector Machine
  14. Zaleha K, Nasiratul_shahida MN, Siang HY, Kamaruzzaman BY
    Sains Malaysiana, 2016;45:1019-1024.
    Meiobenthos in Bidong Archipelago in coastal water of the South China Sea is hypothesised to have a certain trend of
    distribution particularly in the island ecosystem where it is usually having different type of sea bottom. Nonetheless, since
    it is located in a tropical area, the trend at the sub-tidal could be less obvious due to absent of clear season. Meiobenthic
    sampling was carried out in Karah Island, an island in Bidong Archipelago, from the intertidal, towards the sub-tidal
    zone covering the coral and non-coral area to see the trend in the density and composition. A transparent hand core
    was used to collect benthos samples. Nematoda and harpacticoid copepods dominated the intertidal and sub-tidal zone
    respectively. Harpacticoid copepods were higher in density in the non-coral sediment than the coral area. This could be
    due to the high content of silt and clay in the coral area (2.98% of silt and clay). The 2-dimension MDS analysis on the
    density data indicated the highest degree of scattering and an over-lapping condition for those intertidal and sub-tidal
    samples respectively. ANOSIM result showed that the degree of similarity was lower at the intertidal (70%) than the subtidal
    (reaching 90%) in the first sampling before both became no significant different in the second sampling. It could
    indicate the stable condition in the subtidal than the intertidal ecosystem. The comparatively low density of meiobenthos
    could indicate their response towards the environmental condition in the area which will only be confirmed by long term
    ecological study.
    MeSH terms: Aluminum Silicates; Animals; China; Nematoda; Seasons; Ecosystem; Copepoda; Anthozoa; Islands
  15. Irshad M, Ullah F, Mehmood S, Khan AU
    Sains Malaysiana, 2016;45:1013-1018.
    Allelopathy is a process in which one plant species may usefully or adversely affect the growth of other plant species
    through the production of allelochemicals. During the present investigation, mulch effect of Jatropha curcas leaves was
    evaluated on seed germination and seedling growth of maize varieties viz. Pioneer (V1), Azam (V2) and Jalal (V3). Mulch
    was applied at 1 and 2 tons/hectare. Phenolic compounds were detected in Jatropha curcas leaf (131.15 mg gallic acid
    eq./gm extract). Mulch applied at 2 tons/hectare significantly reduced seed germination (%), germination index, relative
    water content, root width and seedling dry weight. From the findings of the present investigation, it was inferred that
    Jatropha curcas leaves exhibited phytotoxic effects on maize at high concentrations.
    MeSH terms: Biological Phenomena; Zea mays; Gallic Acid; Phenols; Pheromones; Seeds; Water; Plant Leaves; Plant Roots; Germination; Jatropha; Seedlings; Allelopathy
  16. Osama Ala’yed, Ying TY, Azizan Saaban
    Sains Malaysiana, 2016;45:1007-1012.
    In this article, a fourth order quintic spline method has been developed to obtain numerical solutions for second order
    boundary value problems with Dirichlet boundary conditions. The developments of the quintic spline method and
    convergence analysis were presented. Three test problems have been considered for comparison purposes. The numerical
    results showed that the quintic spline method is more accurate compared to existing cubic spline method when solving
    nonlinear second order boundary value problems but vice versa when solving linear second order boundary value
    problems.
    MeSH terms: Algorithms; Models, Theoretical
  17. Zaharuzaman Jamaluddin, Ahmad Mahir Razali, Zainol Mustafa, Mohd Rashid Ab Hamid
    Sains Malaysiana, 2016;45:999-1006.
    The aim of this article was to validate an instrument of quality management practices (QMPs) and performance
    measurement for the manufacturing industry in Malaysia. QMPs and performance were measured using the following
    six value indicators: Management commitment, training, process management, quality tools, continuous improvement
    and organisational performance. A total of 480 questionnaires were distributed and 210 questionnaires were valid for
    analysis. A confirmatory factor analysis (CFA) approach was employed using analysis of moment structures (AMOS)
    software. The results for the hypothesised CFA model showed the following fit statistics: Comparative fit index (CFI) =
    0.924, Tucker Lewis index (TLI) = 0.913 and root mean square error of approximation (RMSEA) = 0.061. The values of
    CFI and TLI ≥ 0.9 and at the same time the value of RMSEA ≤ 0.08 showed that CFA model fits the data very well. Hence,
    the results of the study can be used by managers in manufacturing companies to consider and adapt their QMPs and
    performance assessments toward increasing competitiveness
  18. Iskandar Shah Mohd Zawawi, Zarina Bibi Ibrahim
    Sains Malaysiana, 2016;45:989-998.
    In this paper, the fully implicit 2-point block backward differentiation formula and diagonally implicit 2-point block
    backward differentiation formula were developed under the interpretation of generalized differentiability concept for
    solving first order fuzzy differential equations. Some fuzzy initial value problems were tested in order to demonstrate the
    performance of the developed methods. The approximated solutions for both methods were in good agreement with the
    exact solutions. The numerical results showed that the diagonally implicit method outperforms the fully implicit method
    in term of accuracy.
    MeSH terms: Algorithms; Cell Differentiation; Numerical Analysis, Computer-Assisted
  19. Aziz AM, Omar MZ, Salleh MS
    Sains Malaysiana, 2016;45:977-987.
    Pemprosesan logam separa pepejal yang juga dikenali sebagai pembentukan-tikso merupakan suatu kaedah pemprosesan
    yang secara relatifnya adalah baharu jika dibandingkan dengan kaedah pemprosesan biasa seperti penuangan dan
    penempaan. Sebelum pembentukan-tikso dapat dilakukan, aloi berkenaan perlu melalui langkah awal persediaan iaitu
    dengan mengubah mikrostruktur asal berbentuk dendritik kepada bentuk hampir sfera. Ini diikuti dengan pemanasan
    semula ke julat suhu separa pejal (iaitu sekitar 30-50% cecair) dan seterusnya proses ubah bentuk ke dalam acuan
    menggunakan mesin penekanan hidraulik. Antara kaedah utama yang biasa digunakan bagi penyediaan bahan aloi
    ini adalah tuangan cerun penyejukan, pengadukan mekanik dan kaedah terma langsung. Kajian ini memberi tumpuan
    kepada evolusi mikrostruktur aloi aluminium A333 (Al-7.5Si-3.1Cu) daripada bentuk dendritik kepada hampir sfera
    sebagai persediaan untuk diproses melalui pembentukan-tikso kelak. Kaedah tuangan cerun penyejukan digunakan
    dalam kajian ini kerana kaedah ini diketahui berkesan tapi mudah digunakan. Nilai saiz ira dan faktor bentuk dianalisis
    berdasarkan kepada suhu tuangan dan panjang cerun penyejukan berbeza yang digunakan. Di samping itu, kaedah
    kalometri pengimbas perbezaan juga diguna pakai dalam mengenal pasti suhu sempadan pepejal dan sempadan cecair
    aloi ini. Saiz ira fasa pepejal α-Al paling kecil dan nilai faktor bentuk terbaik yang diperoleh dalam kajian ini berlaku
    pada suhu tuangan 620°C dan panjang cerun 300 mm, iaitu masing-masing pada 15.3 µm dan 0.54.
  20. Hazwan Halimoon, Abdul Rashid Hussain, Kouzani A, Muhd Nazrul Hisham Zainal Alam
    Sains Malaysiana, 2016;45:969-976.
    In this paper, a minibioreactor platform made of low cost polymers is presented. The minibioreactor prototype was designed
    as an alternative solution for carrying out microbial fermentation experiments in laboratory. The minibioreactor prototype
    has a working volume of 1.5 mL and was fabricated from poly(methylmethacrylate) (PMMA) and poly(dimethylsiloxane)
    (PDMS) polymers. Cell density was measured online whilst agitation rates and the temperature of the reactor content
    can be tightly controlled to desired set-point values. As proof-of-concept, various S. cerevisae fermentation experiments
    were conducted. In every experiment, the minibioreactor operated stably for the entire length of operation which was
    nearly 40 h with very minimal volume loss i.e. about 2.8 µL·h-1 at 37ºC. The minibioreactor has the maximum oxygen
    transfer rate (OTR) of 16.6 mmol·L-1·h-1 under the agitation rate of 300 rpm. Under these conditions, cell specific growth
    rate as high as 0.291 h-1 was obtained. The experimental data in the minibioreactor operation was also reproducible
    using shake flask where similar growth profiles were attained under a similar growth conditions.
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