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  1. elvira pederes de lara-tuprio, Varayu boonpogkrong
    Sains Malaysiana, 2017;46:2549-2554.
    n this paper, transformation and differentiation of Henstock-Wiener integrals are discussed. The approach is by Riemann sums. The idea is more transparent than that of classical Wiener integral.
  2. Zurni Omar, Mohamed Suleiman
    A new method called parallel R-point explicit block method for solving a single equation of higher order ordinary differential equation directly using a constant step size is developed. This method calculates the numerical solution at R point simultaneously is parallel in nature. Computational advantages are presented by comparing the results obtained with the new method with that of the conventional 1-point method. The numerical results show that the new method reduces the total number of steps and execution time. The accuracy of the parallel block and the conventional 1-point methods is comparable particularly when finer step sizes are used.
  3. Zurina M, Idris A, Mohamad Roff M
    Bemisia tabaci (Gennadius) merupakan spesies lalat putih utama dan berbahaya kepada pertanian. Kajian telah dijalankan di Stesen MARDI Jalan Kebun, Klang, Selangor dari 9 September 2006 hingga 11 November 2007. Objektif kajian ini adalah untuk menilai kesan populasi lalat putih terhadap tanaman cili yang diberi kadar nitrogen yang berbeza (0, 33, 43, 53 g/pokok). Keputusan kajian menunjukkan pokok cili yang dibaja dengan kadar nitrogen yang tinggi menyebabkan peningkatan yang bererti (P<0.05) kepada populasi B. tabaci peringkat belum matang berbanding pada pokok cili yang dibajakan nitrogen pada kadar rendah. Min bilangan B. tabaci pada peringkat belum matang per aras kanopi adalah berbeza secara signifikan (P<0.05) antara aras kanopi dan antara perlakuan. Secara amnya, min bilangan telur dan larva B. tabaci adalah lebih tinggi secara bererti (P<0.05) pada aras kanopi atas berbanding tengah dan bawah. Walau bagaimanapun, min bilangan pupa B. tabaci adalah tinggi secara signifikan (P<0.05) pada aras kanopi bawah berbanding aras kanopi atas dan tengah. Min bilangan B. tabaci pada peringkat belum matang adalah berbeza secara bererti (P<0,05) mengikut minggu selepas pokok cili ditanam pada semua perlakuan. Secara amnya, populasi B. tabaci lebih tinggi semasa awal musim penanaman dan menurun selepasnya hingga ke akhir musim kecuali pada minggu ketiga dan ketujuh selepas pokok cili di tanam.
  4. Zurina AM, Asma' M, Raja Latifah RJ, Noriah Y
    Sains Malaysiana, 2014;43(11):1729-1735.
    Recent studies suggested that exposure to household smoking (HHS) could be a modifiable risk factor for caries development among children. Majority of the studies were cross sectional in nature. Therefore, a case-control study was designed to test the hypothesis that HHS is a risk factor to caries experience in permanent teeth. Calculation of sample size was based on the ratio of 1 case to 4 controls. Case was defined as a child aged 13-14 years old with caries in at least one second permanent molar and control was defined as a child from the same age and school with no caries second permanent molars. Matching was done for gender and ethnicity. School dental records provided information on oral health status and oral hygiene status. Information on HHS, socio-economic status, child’s smoking status and child’s oral health practices were obtained from a self- administered questionnaire, completed by the children and their parents. The result showed that 55.9% of the case group was exposed to HHS, as compared to 44.1% among the control group. In the final multiple logistic regression model after controlling for important risk factors for caries, children with caries were almost twice as likely to have been exposed to HHS for more than 10 years as compared to children with no caries, (Adjusted OR=1.90 and 95% CI=1.35, 2.60). In addition, children who only received dental care from the school dental service had reduced risk of having dental caries by more than one third (36%) as compared with those who received dental care from school dental service (SDS) as well as had additional dental problem solving visit outside SDS (Adjusted OR=0.64 and 95% CI=0.50, 0.90). It is concluded that exposure to HHS for a long duration (> than 10 years) increase the risk to have caries experience in permanent teeth of children.
    Study site: 12 secondary schools, Kelang District, Selangor, Malaysia
  5. Zunaidah Abu Samah, Devinder Kaur Ajit Singh, Resshaya Roobini Murukesu, Nor Azlin Mohd Nordin, Suzana Shahar, Mohd Azahadi Omar, et al.
    Sains Malaysiana, 2018;47:2769-2776.
    Falls are a public health concern among older adults. There is a need to take significant measures such as screening for the risk of a fall as a means of prevention and management. A cross-sectional study was conducted to determine discriminative and predictive ability of physical performance measures in identifying the risk of fall among Malaysian community dwelling older adults. Three hundred twenty-five Malaysian community dwelling older adults aged 60 years and above (67.67+ 5.5 years) participated in this study. This study was a part of a larger longitudinal study ‘LRGS TUA’. Physiological Profile Assessment (PPA), a comprehensive tool for quantifying risk of fall was used as a standard measure of comparison to 6 Meter Gait Speed (GS), Timed Up and Go (TUG) and Walking While Talking (WWT) tests to establish discriminative and predictive ability. Participants recorded incidence of falls in a ‘falls diary’ over a span of six months. To determine the optimum cut off scores of the test identified to classify fall risk, receiver operator curves (ROC) were used and its sensitivity and specificity were calculated. A significant mean difference between fallers and non-fallers was demonstrated only with TUG test (p<0.05). TUG test cut off score in discriminating older adults at risk of fall was established at eight seconds, with a sensitivity and specificity of 83.95% and 32.4%, respectively, in this study. Eighty-four percent older adults who experienced a fall in our study were identified to be at risk of fall when screened using this TUG cut off score. Our study results suggested TUG test to be an optimal screening tool for risk of fall among community dwelling older adults.
  6. Zun Liang Chuan, Nor Azura Md Ghani, Choong-Yeun Liong, Abdul Aziz Jemain
    Sains Malaysiana, 2013;42:1339-1344.
    Oleh sebab kejadian jenayah bersenjata api semakin berleluasa, pengecaman senjata api yang digunakan oleh penjenayah amat diperlukan sebagai bahan bukti dalam mahkamah. Beberapa sistem pengecaman senjata api telah diutarakan sebagai pengganti kepada cara penyiasatan tradisional yang amat bergantung kepada kepakaran ahli balistik. Pemetakan rantau tumpuan (ROI) berdasarkan kedudukan titik sauh (PAP) sempadan bulatan kesan pin peletup pada tapak kelongsong peluru merupakan langkah yang amat penting dalam sistem pengecaman senjata api automatik. Walau bagaimanapun, kaedah yang digunakan dalam kajian lepas bagi mengesan PAP sempadan bulatan tersebut adalah sangat kompleks dan memerlukan masa pemprosesan yang panjang. Kajian ini menerokai algoritma yang efisien dan berkemampuan untuk mengesan PAP sempadan bulatan secara automatik. Algoritma yang diutarakan merupakan gabungan daripada penapis penajaman reruang, penormalan histogram, pengambangan dan penganggar kuasa dua terkecil tak berpemberat. Dua kaedah pengambangan yang terkenal telah diuji dan dibandingkan, iaitu kaedah pengambangan berasaskan pengelompokan dan kaedah berasaskan entropi. Di samping itu, penerokaan kesan saiz dan bentuk ROI terhadap kadar pengelasan senjata api turut dipersembahkan. Sebanyak 747 imej kesan pin peletup jenis sempadan bulatan peletup yang dihasilkan oleh lima pucuk pistol yang berlainan daripada jenis yang sama digunakan untuk menguji algoritma yang diutarakan. Kadar pengelasan imej kesan pin peletup yang memberangsangkan (> 95%) telah dicapai dengan algoritma yang dicadangkan. Kajian juga mendapati bahawa saiz dan bentuk pemetakan ROI mempunyai kesan langsung terhadap kadar pengelasan senjata api.
  7. Zulkifli Yusop, Harisaweni, Fadhilah Yusof
    Sains Malaysiana, 2016;45:87-97.
    Rainfall intensity is the main input variable in various hydrological analysis and modeling. Unfortunately, the quality of rainfall data is often poor and reliable data records are available at coarse intervals such as yearly, monthly and daily. Short interval rainfall records are scarce because of high cost and low reliability of the measurement and the monitoring systems. One way to solve this problem is by disaggregating the coarse intervals to generate the short one using the stochastic method. This paper describes the use of the Bartlett Lewis Rectangular Pulse (BLRP) model. The method was used to disaggregate 10 years of daily data for generating hourly data from 5 rainfall stations in Kelantan as representative area affected by monsoon period and 5 rainfall stations in Damansara affected by inter-monsoon period. The models were evaluated on their ability to reproduce standard and extreme rainfall model statistics derived from the historical record over disaggregation simulation results. The disaggregation of daily to hourly rainfall produced monthly and daily means and variances that closely match the historical records. However, for the disaggregation of daily to hourly rainfall, the standard deviation values are lower than the historical ones. Despite the marked differences in the standard deviation, both data series exhibit similar patterns and the model adequately preserve the trends of all the properties used in evaluating its performances.
  8. Zulkifli Mohd Nopiah, Mohd Helmi Jamalluddin, Nur Arzilah Ismail Haliza Othman, Izamarlina Asshaari, Mohd Hanif Osman
    Sains Malaysiana, 2012;41:1171-1176.
    Students’ performance cannot be based solely on their ability to answer questions. The accuracy of the examination questions must also be considered when measuring the outcome of the course. The objective of this paper was to study the reliability of a question and its impact on students’ performance. A well-constructed question should be commensurate with the level of the intended knowledge. In this study, results from a linear algebra examination were analysed using the Rasch Model. The Rasch Model was used to analyse the reliability, non-redundancy and suitability of examination questions. The results showed that, in this particular case, the linear algebra questions were correctly constructed without any redundancy and suitable for the intended students.
  9. Zulkifli Mohamed, Omar Samat, Daud Mohamad
    Stock market investing is undoubtedly challenging. Investors have to deal with random, vague and ambiguity stock price volatility before embarking on investment decision. Due to these weaknesses, the conventional model has several limitations; as a result investors are demanding for a new robust model which is able to represent their real situation to solve the uncertainty issues. In this study we developed a new fuzzy portfolio selection model using semi-variance as a risk measure integrates with investor’s judgment on assets’ future performance. Linear programming approach was used to optimize the portfolio risk and return. Empirical data showed that the model were able to derive a resourceful portfolio compared to the naïve portfolio selection.
  10. Zulkarnain, Rozli Zulkifli, Mohd Jailani Mohd Nor
    Sains Malaysiana, 2011;40:1179-1186.
    Penyelidikan ini dilakukan untuk mengkaji ciri akustik serabut sabut kelapa yang berpotensi digunakan sebagai bahan penyerap bunyi. Untuk meningkatkan ciri akustik serabut sabut kelapa pada frekuensi rendah, lapisan berliang digunakan di bahagian depan atau belakang bertujuan untuk meningkatkan nilai galangan permukaan. Bahan selanjutnya dilapisi dengan plat berlubang dengan nisbah keluasan yang berbeza. Sampel diuji mengikut piawaian antarabangsa ASTM E 1050-98 untuk menentukan pekali penyerapan bunyi. Daripada hasil uji kaji, plat 1 mm berlubang yang diperbuat daripada kepingan aluminium yang melapisi serabut sabut kelapa, didapati bahawa nilai maksimum pekali penyerapan bunyi berada pada frekuensi antara 2750 Hz hingga 2825 Hz iaitu dengan nilai 0.97. Nilai nisbah keluasan plat berlubang memberikan pengaruh penurunan pekali penyerapan bunyi pada frekuensi tinggi. Penurunan nilai pekali penyerapan bunyi terjadi apabila plat berlubang mempunyai nilai nisbah keluasan di bawah 0.22. Akan tetapi, penggunaan plat berlubang boleh meningkatkan prestasi penyerapan bunyi serabut sabut kelapa pada frekuensi rendah. Kesepakatan yang baik diperoleh daripada keputusan uji kaji dan analisis dengan pendekatan rangkaian elektrik setara yang digunakan untuk menghitung nilai pekali penyerapan bunyi. Ini menunjukkan bahawa pendekatan rangkaian elektrik setara boleh digunakan untuk merancang dan mengoptimumkan ciri akustik serabut sabut sebagai bahan penyerap bunyi.
  11. Zulkafli Abdul Rashid, Mohammad Noor Azmai Amal
    Sains Malaysiana, 2018;47:1941-1951.
    This study assesses the influence of water quality on fish occurrences in Sungai Pahang, Maran District, Pahang, Malaysia. Water quality and fish samplings were conducted at seven sampling sites in the district for 13 consecutive months. We used canonical correspondence analyses (CCA) to determine the influence of water quality on monthly fish species occurrences. The ranges of water quality parameters were quite high considering the measurements were made during rainy and dry seasons throughout the year. A total of 2,075 individual fish was captured which comprised of 22 different families and 65 species. Family Cyprinidae recorded the highest number of fish species of the area (27 species; 41.5%), followed by Bagridae (five species; 7.69%) and Pangasiidae (five species; 7.69%). Three fish species categorized as endangered, including Balantiocheilos melanopterus, Probarbus jullieni and Pangasianodon hypophthalmus were also collected. The collected fish species were divided into three groups (A to C), which was clearly separated in the CCA ordination diagram. The most important water quality variables for the fish occurrences in this river were pH, followed by temperature, conductivity, alkalinity and phosphate. Data analysis indicates that the occurrence of fishes were influenced by a combination of water quality parameters, but not associated with sampling month. The results present a new data from a study of fish assemblage and their habitat condition which may be important in fisheries activity and fish conservation of the river in the future.
  12. Zulham, Jusuf AA, Indarti J, Lisnawati
    Papanicolaou test is a diagnostic test for uterine cervical cancer screening and routinely examined. It has limitations. A better technique is needed to identify true cervical malignancy process. Molecular cancer marker detection may have high the sensitivity and specificity in detecting cancer. Survivin, a marker candidate, is upregulated in many malignancy processes. Ninety women have joined in this cross sectional study by consecutive sampling. Survivin expression was examined by indirect immunoperoxidase method. It was predominantly found in metaplastic cells. Correlation between survivin expression and Papanicolaou test results was calculated by Fischer’s-exact test. Using Papanicolaou test result as an indicator for the presence of uterine cervical abnormalities, the performance indicators were calculated. Fischer’s-exact test showed that survivin expression was not significantly useful as cervical cancer molecular marker. Survivin expression of the uterine cervical exfoliative cells cannot be used as a diagnostic test for uterine cervical malignancy process.
  13. Zulfahmi Ali Rahman, Sahibin Abdul Rahim, Wan Mohd Razi Idris, Nai CF, Jasni Yaakob
    Tinjauan sepanjang lebuhraya Puchong-Kajang telah dijalankan khususnya di kawasan Puchong, Selangor. Terdapat 12 stesen telah dilawati dan 6 daripadanya telah dilakukan pensampelan tanah bagi analisis makmal. Cerun-cerun yang terbabit dengan pensampelan ini melibatkan cerun jenis tanih dengan julat darjah luluhawa di antara gred IV dan VI. Sampel-sampel tanih yang diambil mewakili cerun yang mengalami kegagalan dan cerun yang stabil. Ciri-ciri fiziko-kimia tanih yang dikaji melibatkan kandungan air segar dan dalam keadaan tepu, kandungan bahan organik, taburan saiz zarah, ketumpatan pukal dan sebenar, keporosan tanah, serakan liat, pH dan kandungan oksida ferum. Kandungan air tanah segar menunjukkan peratusan yang lebih tinggi pada cerun gagal berbanding cerun yang stabil. Semua sampel menunjukkan kandungan air tanah lapangan di bawah tahap kandungan air tepu. Kandungan bahan organik adalah sangat rendah (<2%) dan tanah boleh dikelaskan sebagai berpotensi tidak stabil. Terdapat hubungan positif yang jelas antara kandungan air dan bahan organik khususnya pada cerun gagal. Porositi tanah menunjukkan perkaitan positif terhadap lempung dan kandungan bahan organik. Kebanyakan tanah dikelaskan sebagai bertekstur lempung berpasir berbanding tekstur lain. Nilai-nilai koefisien serakan liat menunjukkan struktur tanah berada dalam kategori stabil hingga sangat stabil berbanding satu stesen yang dikelaskan sebagai tidak stabil. Secara umumnya, tanah terdiri daripada jenis asidik (pH4.87 - pH4.34) dengan kehadiran oksida ferum kurang daripada 6%.
  14. Zulfahmi Ali Rahman, Umar Hamzah, Noorulakma Ahmad
    Hydrocarbon is a light-non aqueous phase liquid or known as LNAPL. It poses environmental hazard if accidentally spilled out into the soil and water systems as a result of its insoluble nature in water. LNAPL component infiltrates into soil through pore spaces and afloat at the top of groundwater level. Some of this hydrocarbon would trap and clog within the voids, difficult to remove and costly to clean. The occurence of hydrocarbon in the soil definitely degraded the behaviour of soils in terms of engineering properties. This study aimed to investigate the engineering properties of oil-contaminated soil for two different residual soils originally developed from in-situ weathering of granitic and metasedimentary rocks. The physical characterisations of the soil were determined including particle size distribution, specific gravity test and x-ray diffraction (XRD). The engineering parameters for the contaminated and uncontaminated soils were Atterberg limits, compaction and soil shear strength (UU tests). The amounts of hydrocarbon added to soil were varied at 0%, 4%, 8%, 12% and 16% of dried weigth of soil samples. The results from the particle size distribution analysis showed that residual soil from granitic rock comprises of 38% sand, 33% silt and 4% clay while metasedimentary soil consists of 4% sand, 43% silt dan 29% clay. The mean values of specific gravity for the granitic and metasedimentary soils were 2.56 and 2.61, respectively. The types of minerals present in granitic soil sample were quartz, kaolinite and gibbsite while metasedimentary soil consists of quartz and kaolinite. The Atterberg limits value decreased as a result of increasing amount of added hydrocarbon into the soil. A similar behaviouir was observed with the values of maximum dry density and optimum water content with increasing hydrocarbon content. The overall unconsolidated undrained shear strength, Cu showed a decreasing trend with the increase in hydrocarbon content.
  15. Zulfahmi Ali Rahman, Sahibin Abd. Rahim, Wan Muhd Razi Idris, Jasni Yaakob
    Sains Malaysiana, 2007;36(2):105-116.
    Secara geologi, kawasan Cameron Highland terdiri daripada batuan granit batolit yang merejah ke dalam batuan sedimen yang lebih tua. Rejahan jasad igneus asidik ini menyebabkan pembentukan batuan meta-sedimen dan batuan metamorfik lain sebagai sisa bumbung. Sekis sering ditemui telah mengalami luluhawa tinggi hingga sepenuhnya, berwarna kelabu cerah hingga gelap dengan butiran halus hingga sederhana dan struktur foliasi yang ketara. Manakala batuan granit mengandungi mineral kuarza, felspar dan butiran biotit dan/atau turmalin. Kebanyakan cerun potongan jalan raya yang dibina merentasi jasad batuan ini dan survei ketidakstabilan cerun dilakukan berdasarkan jenis, geometri dan cirian fiziko-kimia tanah cerun. Hasil cerapan lapangan menunjukkan bahawa jenis cerun yang gagal adalah jenis cerun tanah yang terdiri daripada jenis gelinciran cetek dan dalam. Antara faktor yang menyumbang kepada ketidakstabilan cerun adalah geometri cerun seperti cerun yang tinggi dan sudut muka cerun yang curam, sifat keperoian tanah pada cerun dan kekurangan litupan vegetasi permukaan. Ini menyebabkan permukaan cerun terdedah kepada hentaman terus hujan. Kesan daripada air larian permukaan juga menyebabkan pembentukan alur-alur hakisan pada muka cerun tanah. Sifat fiziko-kimia bahan cerun (tanah) seperti taburan saiz partikel, pH, kandungan ferum oksida, bahan organik, kandungan air, ketumpatan pukal dan sebenar serta keporosan juga didapati memainkan peranan sebagai faktor yang dalaman dalam mempengaruhi kestabilan cerun tertentu yang dikaji. Julat pH tanah yang rendah (sifat asidik) pada semua cerun mengurangkan kandungan ferum oksida dalam tanah yang bertindak sebagai bahan penyimen tanah. Ini menyebabkan agregatan tanah menjadi lemah dan mudah terhakis.
  16. Zulfahimi A, Wan Zuhairi W, Raihan M, Sahibin A, Wan Mohd Razi I, Tukimat L, et al.
    Sains Malaysiana, 2012;41:303-312.
    Amang or tin tailing is commonly found in the vicinity of disused mining area and responsible in downgrading the water quality, landscape and mechanical behaviour of soils. It was generated from extraction process of separating valuable metal from particular ore. This paper presents the geotechnical characteristics of amang-contaminated clay soil. The geotechnical properties of uncontaminated soils were studied in order to compare to that of amangcontaminated soils. The base soil used in this study represents completely weathered horizon of metasedimentary rock. Meanwhile, tin tailing sample was taken from the disused mine at Sungai Lembing, Pahang. The geotechnical characterisations of base soil and contaminated soils were determined based on consistency index, compaction behaviour, hydraulic conductivity and undrained shear strength (UU tests). Contaminated soil samples were prepared by adding 5, 10 and 20% of tailing, based on dry weigh of the studied base soil. The results from the particle size distribution analysis showed that residual soil from metasedimentary rock comprised 42.6% clay, 32.2% silt and 25.2% sand whilst tailing was dominated by 98% of sand fraction. XRD analysis indicated the presence of quartz, kaolinite and muscovite minerals in the studied soil. The specific gravity of soil used is 2.67 and the pH is 3.88. Tailing found to have higher specific gravity of 3.37. The consistency index of contaminated soils showed that liquid limit, wL and plastic limit, wP decreased with the increase in the percentage of tailing added to the soil samples. The value of maximum dry density, dry max increased while optimum moisture content decreased due to the increase in tailing content in soil sample. The permeability of contaminated soil also increased with the increase in tailing
    contents ranged from 19.8 cm/hr to 23.8 cm/hr. The undrained shear strength, Cu, of contaminated soil decreased from 646 kPa (5% of tailing) to 312 kPa (20% of tailing) suggesting that the presence of tailing has influenced the geotechnical properties on the studied soil.
  17. Zulaikah Mohamed, Nazlina Ibrahim, Ismail Ahmad
    Sains Malaysiana, 2008;37(1):107-113.
    Methanol extract of Melastoma malabathricum leaves inhibited the growth of Staphylococcus aureus and six clinical isolates of Methicilin Resistant Stapyhlococcus aureus (MRSA 1-6). The minimum inhibitory concentration (MIC) of test substance was 1.565mg/ml and the minimum bacteriocidal concentration (MBC) was 3.125 mg/ml. The methanol extract suppressed RNA synthesis at 10 mg/ml as shown by RNA profile which was devoid of three bands compared to the control. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis using seven primer pairs was only successful in amplifying four cDNA amplicons. The failure to amplify three cDNA amplicons for three primer pairs corresponding to gyrA, femA and nuc genes, implied the possibility of suppression of the corresponding mRNA. Electrophoretic separation of endogenous and exogenuos bacterial proteins showed that three and five protein, respectively were not expressed. One endogenous and three exogenous proteins were over-expressed in treated MRSA compared with untreated control. The results of the molecular and proteomic analyses are in agreement, and based on primers being used, methanol extract of M. malabathricum leaves possibly inhibits MRSA growth through inhibition of DNA synthesis, peptidoglycan production, and nuclease production.
    Keywords: Methicillin resistant Staphylococcus aureus; Melastoma malabathricum; gene expression; protein production
  18. Zuhaili Zakaria, Sarani Zakaria, Chin HC, Sharifah Nabihah Syed Jaafar, Umar Adli Amran, Sinyee Gan, et al.
    Sains Malaysiana, 2018;47:2573-2580.
    In this study oil palm empty fruit bunches (EFB) fibres was used to synthesize biophenolic resin (BPR) at a different
    formaldehyde/liquefied empty fruit bunches (F/LEFB) molar ratio which is 1.0, 1.5 and 2.0. The higher molar ratio of F/
    LEFB used has resulted in an increased of viscosity and solid content of BPR resin. The first decomposition of BPR resin
    occured around 86 to 130°C due to the evaporation of low molecular weight substance which were water, free phenol
    and formaldehyde. Glass fibre reinforced biophenolic composite (BPC) and glass fibre reinforced biophenolic elastomer
    composite (BPEC) was successfully fabricated using BPR resin. The impact strength and flexural strain of BPEC were
    higher than that of BPC. The impact strength of BPEC 1.5 was the highest at 47.71 kJm-2. However, the flexural strength
    of BPEC was lower compared with BPC, which the highest flexural strength was obtained by BPC 1.0 at 65.18 MPa. The
    cross-sectional image from scanning electron microscope (SEM) of BPEC and BPC confirmed the presence of epoxidized
    natural rubber (ENR) improved the compatibility between glass fibre and BPR resin.
  19. Zou LJ, Yang JT, Wu QG
    Sains Malaysiana, 2017;46:1183-1189.
    Solanum nigrum L. is a species highly valued for its medicinal properties. In the present study, an efficient propagation system was established by using five explants of S. nigrum namely, roots, leaves, rooted hypocotyls, nodal segments and petioles. Various types of plant growth regulators (PGRs) were used to determine the most effective hormone combination for callus induction and organogenesis. Zeatin (ZT), thidiazuron (TDZ), kinetin (Kin) and indole-3-acetic acid (IAA) were found to induce multiple shoots. Shoot organogenesis was induced in the five explants. The highest mean for number of shoots per petioles (31.54±5.76) and rooted hypocotyls (44.00±1.51) with a 100% induction rate was obtained on Murashige and Skoog (MS) medium fortified with 0.4 mg/L IAA and 3.0 mg/L ZT. MS medium containing 0.4 mg/L IAA and 3.0 mg/L TDZ was found to be optimal for shoot regeneration of roots, leaves and nodal segments. The highest regeneration frequency (100%) with mean numbers of shoots equal to 38.77±6.87 for roots, 42.73±7.75 for leaves and 56.73±7.98 for nodal segments was produced. Regenerated shoots rooted effectively on half-strength MS medium and acclimatized successfully in soil with a 100% survival rate and normal growth. The protocol can be used for the large-scale propagation of S. nigrum to meet the increasing demand of commercial cultivation.
  20. Zong-ji Yang, Taro Uchimura, Jian-ping Qiao, Jian-ping Qiao
    Sains Malaysiana, 2017;46:2029-2034.
    Prevention and mitigation of rainfall induced geological hazards after the Ms=8 Wenchuan earthquake on May 12th, 2008 were significant for rebuild of earthquake hit regions. After the Wenchuan earthquake, there were tens of thousands of fractured slopes which were broken and loosened by the ground shaking, they were very susceptible to heavy rainfall and change forms into potential debris flows. In order to carry out this disaster reduction and prediction effectively in Longmenshan region, careful real-time monitoring and pre-warning of mountain hazards in both regional and site-specific scales is reasonable as alternatives in Wenchuan earthquake regions. For pre-warning the failure of fractured slopes induced by rainfall, the threshold value or the critical value of the precipitation of hazards should be proposed. However, the identification of critical criterion and parameters to pre-warning is the most difficult issue in mountainous hazards monitoring and pre-warning system especially in the elusive and massive fractured slopes widespread in Wenchuan earthquake regions. In this study, a natural coseismic fractured landslide in the Taziping village, Hongkou County, Dujianyan City, was selected to conduct the field experimental test, in order to identify the threshold parameters and critical criterion of the fractured slopes of Taziping. After the field experimental test, the correlation of rainfall intensity, rainfall duration and accumulative rainfall was investigated. The field experimental test was capable of identifying the threshold factors for failure of rainfall-induced fractured slopes after the giant earthquake.
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