Displaying publications 161 - 180 of 839 in total

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  1. Radin Maya Saphira Radin Mohamed, AAS, Al-Gheethi, Mohd Shauqi Lutfi Ahmad, Siti Asmah Bakar, Sabariah Musa, Amir Hashim Mohd Kassim
    MyJurnal
    Greywater traditionally receives the least attention compared to other aspects of environmental sanitation. In Malaysia, most of village houses discharged lots of significant portion of greywater into stream without any treatment. Laundry Greywater (LGW) is one of the largest portion of greywater that has been directly discharged to the stream. The aim of this study was to identify the physical and chemical characteristic of laundry greywater quality from the houses and also to evaluate the efficiency of using ceramic waste coarse aggregate filtration for LGW treatment. The effectiveness of the treatment systems was optimized with different Hydraulic Retention Time (HRT) and volume of samples by using Response Surface Methodology (RSM). The samples were taken from the direct discharge point of the laundry greywater at two houses. The results revealed that the efficiency of designed filtration system depended on HRT and volume of samples. The highest Chemical Oxygen Demand (COD) removal from 1 L of LGW and after 3 hrs was 43.31%, while the highest removal of orthophosphate (PO4) (100%) and sodium (Na) (27.48%) were recorded with 2 L and after 2 hrs. It can be concluded that the ceramic waste coarse aggregate filtration was effective in reducing the pollutants in the LGW before the final disposal into the environment.
  2. Mahirah Jahari, Khairunniza-Bejo, S., Abdul Rashid Mohamed Shariff, Helmi Zulhaidi Mohd. Shafri
    MyJurnal
    In this research wok, three different techniques of change detection were used to detect changes in forest areas. One of the techniques used a local similarity measure approach to detect changes. This new approach of change detection technique, which used mutual information to measure the similarity between two multi-temporal images, was developed based on correspondence of the pixel values, rather than the difference in their intensity. Pixels suffering any changes will be maximally dissimilar. The study was conducted using multi-temporal SPOT 5 satellite images, with the resolution of 10 m x10 m on 5th August 2005 and 13th June 2007. The experimental results show that local mutual information provides more reliable results in detecting changes of the multitemporal images containing different lighting condition compared to the image differencing and NDVI technique, specifically in areas with less plant growth. In addition, it can also overcome the problem on selecting the threshold value. Besides, the findings of this study have also shown that band 3, which is sensitive to vegetation biomass, gave the best result in detecting area of changes compared to the others.
  3. Madun, A., Wijeyesekera, D.C., Ahmad Tajuddin, S.A., Zainalabidin, M.H., Yunus, R., Baharudin, M.F.
    MyJurnal
    Seismic surface waves are a non-destructive technique used to obtain the dynamic properties of soil by measuring the shear wave velocity and calculating the shear modulus of soil. The shear modulus is one of the parameters to measure the stiffness of materials. This study evaluates soil profiles and the position of the sensor while conducting measurements of two , soil profiles, i.e. lateral and vertical non-homogeneities, using a continuous surface wave analysis (CSW) and multi-channel analysis of surface waves (MASW). Results showed the dispersive curve demonstrated an increased shear wave velocity with increasing depth for the sensor pair measurements on the clay (between columns), and decreased shear wave velocity with increasing depth for the sensor pair measurements on the column. In both instances the surface wave velocity results influenced by the depth and size of the wavelength, indicating that depth and wavelength controlled the volume of measurement in an elliptical shape. Therefore, the shear wave velocities and thus stiffness measured from the surface wave velocity techniques are represented the volume of soil measured across the sensor length.
  4. Suppiah, S., Kamal, S.H., Mohd Zabid, A.Z., Abu Hassan, H.
    MyJurnal
    Adnexal masses are growths that form near the uterus; the majority being ovarian tumours. Although
    there is no established population-screening tool for detecting ovarian cancer, ultrasound and contrastenhanced
    computed tomography (CECT) are useful imaging tools in the management of adnexal masses.
    Our study aimed to determine the characteristics of malignant adnexal masses on CECT scan and to
    describe common pitfalls in diagnosis of ovarian cancer when interpreting images. We also determined the
    sensitivity and specificity of diagnosing ovarian cancer using CECT. A retrospective study was conducted
    in Hospital Serdang using data from all patients who underwent CECT scan and detected with adnexal
    masses, and had histopathological examination correlation from January 2013 until January 2015. Out of
    the 64 cases analysed; the majority of malignant lesions were serous carcinoma of the ovary (40%). The
    CECT scan characteristics, tumour consistency of mixed type, presence of wall enhancement, septations,
    ascites and peritoneal nodule/omental caking were significantly associated with ovarian malignancy
    (p
  5. Nur Azida Che Lah, Aidy Ali, Napsiah Ismail
    MyJurnal
    Welding process is most widely used in joining components or structures in industry. Although welding is part of a larger category called metals joining, the weld itself still gives significant problems to engineers, researchers and manufacturers until today. Several widely used welding processes, such as the Metal Inert Gas (MIG), Tungsten Inert Gas (TIG), and Manual Metal Arc (MMA), were studied. In the present paper, the characterization of the macrostructure, microstructure, hardness and residual stress distribution are highlighted and discussed to achieve a better understanding of the welded quality which is crucial in determining the welded products.
  6. Muslimah Solehah Mohd Nazri), Intan Syafinaz Mohamed Amin Tawakkal, Nozieana Khairuddin, Rosnita A Talib, Siti Hajar Othman
    MyJurnal
    Jackfruit straws are normally disposed as waste by food industries and vendors which may lead to serious environmental issue. In order to reduce the wastage and negative effects to the environment, jackfruit straw waste generated by jackfruit (Artocarpus heterophyllus) shows potential as bio-based film incorporated with starch. This work describes the effect of different starch and plasticizer contents on mechanical and thermal properties of jackfruit straw powder (JSP)/starch films. Film-forming solutions were prepared and cast by mixing JSP with tapioca starch at different ratios and for the plasticized films, ca. 15 - 40% of plasticizers including sorbitol and glycerol were incorporated into the JSP/starch films respectively. The tensile strength and modulus of JSP/starch films pronouncedly increased with increasing starch content, accompanied with a slight decreasing in the elongation at break. The result demonstrated that starch interacted with JSP, resulting in the formation of a new network to improve the properties of JSP films. FTIR spectrum analyses demonstrated the presence of hydrogen bonding in the JSP/starch film. The tensile strength of the plasticized JSP/starch films decreased with increasing sorbitol and glycerol content from 15% to 40%. However, the plasticizing effect of sorbitol became more significant than glycerol, particularly on the tensile properties and thermal stability. Thermal analysis by thermogravimetric showed an increment in the decomposition temperature with the addition of plasticizers into JSP/starch films. The results suggest that films containing JSP and starch have the potential for the development of edible food packaging materials.
  7. Widad Fadhullah, Mohamad Anuar Kamaruddin, Norli Ismail, Nurulilyana Sansuddin, Hasmah Abdullah
    MyJurnal
    Solid waste management in developing countries including Malaysia is dominated by waste dumpsites which have a high possibility of transporting organic and inorganic pollutants to the underlying groundwater and surface water within the surrounding area. The objective of this study is to characterise the landfill leachates and its surrounding groundwater and river water quality and metals concentrations, namely arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) from Beris Lalang, Kelantan. Nine sampling points were collected within the dumpsite for analysis of in-situ: dissolved oxygen (DO), pH, total dissolved solids (TDS), conductivity, turbidity and ex-situ; Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Suspended Solids (SS) and the results were compared with permissible limits. As and Pb in groundwater samples were collected from the surface of two dug grounds within the vicinity of the dumpsites exceeded the standard of Ministry of Health. Cr, Cu and Pb in leachates exceeded Environmental Quality Act (EQA, 1974)’s standard, whereas Ni, Pb and Zn in surface water of Gali River exceeded the limit of class III National Water Quality Standard (NWQS). Exceeding metals concentration in leachates and its surrounding groundwater and river water relative to their respective standards points out toward potential leachate migration to the waterbodies within the surrounding vicinity of Beris Lalang dumpsite. This study provides the initial baseline data and preliminary monitoring assessments as a first step towards improving water security and waste management in Kelantan.
  8. Norazah, M.A., Rahmani, M., Khozirah, S., Ismail, H.B.M., Sukari, M.A., Ali, A.M., et al.
    MyJurnal
    The extract of Cinnamomum microphyllum showed strong antioxidant activity when it was tested against auto-oxidation of linoleic acid, superoxide, and DPPH radical scavenging activity. Further detailed investigations of the plant constituents and bioactivity studies led to the isolation and identification of known compounds consisting of three lignans, a coumarin, an ester and β-sitosterol. The structures of the compounds were determined using detailed spectroscopic analysis. The lignans were found to possess a significant antioxidant activity when tested against the three assay systems.
  9. Lee, Kah Nyan, Maulidiani, Faridah Abas, Ahmed, Mediani, Leong, Sze Wei, Intan Safinar Ismail, et al.
    MyJurnal
    The ocean has an exceptional resource with various groups of natural products that are potentially useful for biomedical and other applications. Marine sponges have prominent characteristic natural products with high diversity. They produce many vital therapeutic metabolites with prominent biological activities. Marine invertebrates and microbial communities are the primary producers of such metabolites. Among the richest sources of these metabolites, class Demospongiae and the order Haplosclerida and genus Xestopongiae from family Petrosiidae are of interest. This review summarizes the research that has been conducted on two classes, eight orders, twelve families and fourteen genera of marine sponges available in the South East Asia region, covering the literature of the last 20 years. Ninety-five metabolites including alkaloids, sterols, terpenoids, quinones isolated from marine sponges collected in South East Asia along with their bioactivities especially cytotoxicity and antibacterial activities were reported in this review. Chemistry and biology are highly involved in studying marine sponges. Thus, tight collaboration is needed for understanding their taxonomy aspects. This review will outline chemistry and biological aspects, challenge, limitation, new idea and a clear future perspective on the discovery of new drugs from South East Asia’s marine sponges.
  10. Ee, G.C.L., Cheow, Y.L.
    MyJurnal
    Detail chemical studies on Carcinia maingayi have yielded one xanthone, 1,3,7-trihydroxy-2-(3-methylbut-2-enyl)-xanthone, one benzophenone, isoxanthochymol, one benzoic acid derivative 3,4-dihydroxy-methylbenzoate and two triterpenoids, stigmasterol and sitosterol. Meanwhile, investigations on Carcinia parvifolia have afforded one triterpenoid, a-amyrin and two xanthones, cowanin and rubraxanthone. Their structures were derived based on spectroscopic evidence, mainly ID and 2D NMR spectroscopy. Acetylation reaction was carried out on rubraxanthone to yield triacetate rubraxanthone. It was found that the pure rubraxanthone was strongly active against the larvae of Aedes aegypti with LC50 value of 15.49 {lg/ ml and HL-60 cells line with an IC50 value of 7.5 {lg/ ml.
  11. Kamarulzaman, F. A., Mohamad, K., Awang, K., Lee, H. B.
    MyJurnal
    Our continuing research on the Aglaia genus (family Meliaceace) has led us to this first study on the chemical constituents of Aglaia lanuginose (bark). The dichloromethane extract from the bark of Aglaia lanuginose showed cytotoxicity against HL-60 leukaemia cell line (45% inhibition) at 20 µg/ml and was prioritised for further investigation. Repeated chromatography of the dichloromethane extract yielded the known dammarane triterpenes which were identified as cabralealactone (1), methyl eichlerianate (2), cabraleone (3), ocotillone (4), eichleriatone (5), eichlerianic acid (6) and shoreic acid (7) together with the known sterols, sitosterol (9) and stigmasterol (10). Another isolated compound was the aromatic 4-hydroxycinnamyl-acetate (8), which has not been reported to be present in a plant from the Meliaceae family. The structures of all the compounds were elucidated on the basis of spectroscopic methods (IR, MS and NMR). Cytotoxicity testing of 1-10 showed activity only for mixtures of (3, 4), and (5, 6).
  12. Zainab Ngaini, Rafeah Wahi, Dayang Halimatulzahara, Nur An-Nisaa’ Mohd Yusoff
    MyJurnal
    Oil pollution remains a serious concern especially in Malaysia. Many strategies have been employed to overcome oil pollution. In this research, sago waste material abundantly found in Sarawak was used and chemically modified into an oil adsorbent . Sago waste cellulosic residues were modified using fatty acid derivatives. The capability of the chemically modified sago waste to absorb oil from aqueous solution was studied and compared with the untreated sago waste. The modified sago waste showed higher hydrophobicity than the untreated sago waste, implying that it is less affinity for water and also an excellent affinity for oil. This chemically modified sago waste would be the most suitable for applications where engine oil (i.e., Shell Helix HX5) is to be removed from an aqueous environment. The modified sago waste selectively absorbs the oil and remains on the surface and is to be removed when the application is complete.
  13. Nor Nasriah Zaini, Mardiana Saaid, Hafizan Juahir, Rozita Osman
    MyJurnal
    Tongkat Ali (Eurycoma longifolia) is one of the most popular tropical herbal plants as it is believed to enhance virility and sexual prowess. This study looked examined chromatographic fingerprint of Tongkat Ali roots and its products generated using online solid phase-extraction liquid chromatography (SPE-LC) combined with chemometric approaches. The aim was to determine its quality. Pressurised liquid extraction (PLE) technique was used prior to online SPE-LC using polystyrene divinyl benzene (PSDVB) and C18 columns. Seventeen Tongkat Ali roots and 10 products (capsules) were analysed. Chromatographic dataset was subjected to chemometric techniques, namely cluster analysis (CA), discriminant analysis (DA) and principal component analysis (PCA) using 37 selected peaks. The samples were grouped into three clusters based on their quality. The PCA resulted in 11 latent factors describing 90.8% of the whole variance. Pattern matching analysis showed no significant difference (p>0.05) between the roots and products within the same CA grouping. The findings showed the combination of chromatographic fingerprint and chemometric techniques provided comprehensive evaluation for efficient quality control of Tongkat Ali formulation.
  14. Nagoor Basha Shaik, Srinivasa Rao Pedapati, Shazaib Ahsan, Faizul Azly Abd Dzubir, Syed Ali Ammar Taqvi
    MyJurnal
    Leaks and breakdowns of pipelines can lead to catastrophic failures and cause economical losses worldwide. Currently, condition monitoring has become a challenging process because of various reasons such as fluctuating external conditions, natural hazards. Pipelines are installed in severe conditions and are subjected to degradation mainly due to corrosion and metal loss. This study attempted to classify different types of metal loss faults using historical inspection data of oil and gas fields. For this purpose, Support Vector Machines (SVM) were employed to classify and predict various types of metal loss faults which were affecting the life condition of a crude oil pipeline. The historical inspection data was acquired from a crude oil pipeline located in Sudan. Different types of SVM models were trained and quadratic SVM type was selected for the present study due to its high prediction accuracy. The performance evaluation of the proposed SVM model was done using the confusion matrix. The developed SVM model provides promising results with a prediction accuracy of 93.0%. As a result, the fault detection rate (FDR) for all faults is found to be 90.4%, while the misclassification rate (MR) is 9.6%. The prediction of metal loss fault type may help in condition assessment and maintenance schedule to take prior actions for the better life of pipeline which reduces the degradation rate of a pipeline.
  15. Che Soh, A., Mohamad Yusof, U.K., Radzi, N.F.M., Ishak, A.J., Hassan, M.K.
    MyJurnal
    Herbs have unique characteristics such as colour, texture and odour. In general, herb identification is
    through organoleptic methods and is heavily dependent on botanists. It is becoming more difficult to
    identify different herb species in the same family based only on their aroma . It is because of their similar
    physical appearance and smell. Artificial technology, unlike humans, is thought to have the capacity to
    identify different species with precision. An instrument used to identify aroma is the electronic nose.
    It is used in many sector including agriculture. The electronic nose in this project was to identify the
    odour of 12 species such as lauraceae, myrtaceae and zingiberaceae families. The output captured by the
    electronic nose gas sensors were classified using two types of artificial intelligent techniques: Artificial
    Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS). From the result, ANFIS
    has 94.8% accuracy compared with ANN at 91.7%.
  16. Raja Zubaidah Raja Sabaradin, Norashikin Saim, Rozita Osman, Hafizan Juahir
    MyJurnal
    Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) has been recognised as an effective technique to analyse car paint. This study was conducted to assess the combination of Py-GC-MS and chemometric techniques to classify car paint primer, the inner layer of car paint system. Fifty car paint primer samples from various manufacturers were analysed using Py-GC-MS, and data set of identified pyrolysis products was subjected to principal component analysis (PCA) and discriminant analysis (DA). The PCA rendered 16 principal components with 86.33% of the total variance. The DA was useful to classify the car paint primer samples according to their types (1k and 2k primer) with 100% correct classification in the test set for all three modes (standard, stepwise forward and stepwise backward). Three compounds, indolizine, 1,3-benzenedicarbonitrile and p-terphenyl, were the most significant compounds in discriminating the car paint primer samples.
  17. Muhammad Hamizan Jamaludin, Yap, Bee Wah, Hapizah Mohd Nawawi, Chua, Yung-An, Marshima Mohd Rosli, Annamalai, Muthukkaruppan
    MyJurnal
    Familial hypercholesterolaemia (FH) is a genetic disease that causes the elevation of lowdensity lipoprotein cholesterol (LDL-C), which subsequently leads to premature coronary heart disease (CHD). Features which have been reported to be associated with FH include lipids level, tendon xanthomata, and history of CHD. The Ordinal Logistic Regression model using the classification of FH patients with the Dutch Lipid Clinic Network Criteria (DLCN) as the dependent variable (where 1=Possible, 2=Probable, 3=Definite) was developed and evaluated for different types of link functions. The FH patients (n = 449) were recruited from health screening programmes conducted in hospitals and clinics in Malaysia from 2010 to 2018. Results indicate there is a significant association between FH categories with demographic factors (ethnicity and smoking) and physical symptoms (corneal arcus and xanthomata). The Ordinal Logistic Regression using Cauchit link function has lower Akaike Information Criterion (AIC) value, higher Nagelkerke’s R-Square and classification accuracy compared to Probit and Logit link function, diastolic blood pressure, corneal arcus and xanthomata were found to be significant covariates of FH.
  18. Mohd Rezuan M Aspar, Rashidah Abdul Rahim, Mohamad Hekarl Uzir
    MyJurnal
    Yeast producing alcohol dehydrogenase 1 (YADH 1) enzyme has been used as a biocatalyst for the synthesis of an optically active flavouring compound known as citronellol. However, the slow growth of yeast (Saccharomyces cerevisiae) has deterred the progress of biotransformation. The main purpose of this work is to clone the genes producing YADH1 enzyme from yeast into a faster growing bacteria, Escherichia coli. Initially, the sequence of the gene encoding this protein has been identified in the S. cerevisiae Genome Databases (SGD). The so-called Yadh1 gene sequence is located from coordinate 159548 to 160594 on chromosome XV of yeast. Based on this information, two primer sequences (Forward and Reverse) were constructed. Each of these primers will bind to either end of the Yadh1 gene. The Yadh1 gene was then amplified using Polymerase Chain Reaction (PCR) technique. The amplified Yadh 1 gene was successfully cloned into a cloning vector, TOPO TA plasmid. This plasmid also contains a gene which confers resistance to ampicillin. This recombinant
    plasmid was then inserted into Escherichia coli TOP 10 using heat shock protocol at 42oC. Finally, the cloned bacteria containing the recombinant TOPO TA plasmid harbouring Yadh1 gene was able to grow on Luria Bertani (LB) media supplied with antibiotic.
  19. Huat, Bujang B.K, Faisal AIi, Choong, Foong Heng
    MyJurnal
    Residual soils occur in most countries of the world but the greater areas and depths are normally found in tropical humid areas. In these places, the soil forming processes are still very active and the weathering is much faster than the erosive factor. Most residual exhibit high soil suctions for most of the year. The absence of positive pore water pressure except immediately after rain, renders conventional soil mechanics for saturated soil irrelevant. In particular, the effective stress theories of saturated soil are not applicable at the practical leve l. Ignorance or lack of understanding of the geotechnical behavior of soil in the partially or unsaturated state has caused a lot of damages to infrastructures, buildings and other structures. For instances, the collapsibility and volume change of partially saturated soils in connection with the drying or wetting causes a lot of damage to foundation, roads and other structures. As such, the development of extended soil mechanics, which embraces the soil in the unsaturated state or subjected to soil suction, is essential. This paper examines the collapsibility and volume change behavior specifically of an unsaturated residual soil under various levels of applied matric suction (u -u ), and net mean stress (a-u) in a predetermined stress path. The volume change of ;he"' soil is found to be sensitive to both the applied matric suction and net mean stress. The soil is found to exhibit a collapsibility behavior upon a reduction in applied matric suction to 25 kPa at constant net mean stress.
  20. Ai-Hong Chen, Fazrin Mazlan, Saiful-Azlan Rosli
    MyJurnal
    This article aims to quantify the colour discrimination ability by using Total error scores (TES) to categorise colour discrimination level into superior, average or inferior levels under three different types of light sources, with different spectral power distribution. Colour discrimination was investigated using Farnsworth-Munsell 100 hues and compared upon three light sources: compact fluorescent light (CFL), fluorescent light (FL) and light emitting diode (LED). Total error score calculated and pattern of colour caps misplacement plotted used the web-based scoring method (http://www.torok.info/colorvision/fm100. htm). Total error score (TES) for three types of light sources (TES for LED 58.00 ± 18.67, FL 80.00 ± 19.27 and CFL 127.25 ± 28.02) were significantly different [One-way ANOVA (F=9.98, P
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