Browse publications by year: 1997

  1. Leisner JJ, Rusul G, Wee BW, Boo HC, Muhammad K
    J. Food Prot., 1997 Oct;60(10):1235-1240.
    PMID: 31207722 DOI: 10.4315/0362-028X-60.10.1235
    The predominant microbial flora of a specific Malaysian food ingredient, chili bo (containing 9% ground dried chilies, 0.6% acetic acid, and 5 to 10% cornstarch, wt/vol) stored for up to 25 days at 28°C without added benzoic acid (product A) and with 7,000 ppm of added benzoic acid (product B) was examined. Aerobic plate counts for both products were initially 6.2 to 6.5 log CFU/g increasing to 8.5 log CFU/g for product A after 4 days. Aerobic plate counts for product B did not increase during storage. Lactic acid bacteria (LAB) counts increased in product A from 4.8 log CFU/g to 8.3 log CFU/g and in product B from 2.1 log CFU/g to 7 .6 log CFU/g after 17 days. Growth of yeast occurred in product A. Both products exhibited spoilage after 1 to 2 days of storage at 28°C indicated as accumulation of gas bubbles. In addition surface growth of molds (product A) or whitish discoloration (product B) was observed later in storage. For product A the predominant isolates were LAB, Bacillus pumilus , Bacillus subtilis , Staphylococcus spp., and yeasts. B. pumilus and B. subtilis predominated initially whereas the other types of microorganisms predominated after 25 days of storage. B. pumilus and B. subtilis were also predominant in product B, but after 25 days of storage a homofermentative LAB was found in higher numbers (7.6 log CFU/g). Isolates of heterofermentative LAB but not homofermentative LAB or B. pumilus or B. subtilis were able to produce gas during growth in chili bo sterilized by autoclaving at l2l°C for 15 min. Growth of heterofermentative LAB, B. pumilus , and B. subtilis was inhibited by acidifying agents, a nisin-containing supernatant, or incubation at low temperatures.
  2. Rusul G, Chun CK, Radu S
    J. Food Prot., 1997 Jun;60(6):644-648.
    PMID: 31195564 DOI: 10.4315/0362-028X-60.6.644
    The growth of Vibrio cholerae O139 inoculated into cendol (a mixture of coconut milk, brown sugar, and green jelly from rice flour), rojak (prawn paste, sugar, soy sauce, spices, garlic, and peanut gravy), gravy, tofu, fried tofu, and wheat-flour noodles (all except rojak gravy containing the natural microbial flora) was examined at four incubation temperatures (7, 15,25, and 35°C). V. cholerae O139 grew well in cendol incubated at 25 and 35°C but not at 15°C or below. No growth of V. cholerae O139 in rojak gravy was detected at any temperature except for very slow growth at 35°C. V. cholerae O139 inoculated into tofu exhibited slow growth at 25 and 35°C and growth was not detected at 7 and 15°C. However, in fried tofu, the organism entered the growth phase after 12 h of incubation at 25 and 35°C. Growth of V. cholerae O139 was not demonstrated in noodles at any incubation temperatures. Nutrient broth with 1% NaCl added supported the growth of V. cholerae O139 at 25 and 35°C. At both of these incubation temperatures mean generation time was longer at pH 5 than at pH 8. The high variation in growth of V. cholerae O139 in the distinct foods examined might have been due to differences in pH, fat content, and aw. Proper sanitary practices and storage of foods at refrigeration temperatures will help to reduce the possibility of growth by Vibrio cholerae O139 in foods to levels which do not imply a risk for food-poisoning.
  3. Supian Bin Samat, Green S, Beddoe AH
    Measurement of the natural 40K body gamma-ray radioactivity via the whole-body counter (WBC) technique may yield the total body potassium (TBK) status, from which for example, the body cell mass can be derived (Moore et al. 1963). The accuracy of the derived TBK is of course critically dependent on the assumed value of the ratio 40K:TBK. Potassium chloride (KCI) has been widely used as the 40K calibration standard. In reviewing the literature (Burkinshaw 1967; Ross & Morris 1968; Havlik 1970, Young et al 1975; Manocha & Mohindra 1976; Holtzman 1977; Graham 1983; HMSO 1985-1986, Lykken et al 1987; Lan & Weng 1989; Fenwick et al. 1991), it is apparent that inconsistencies occur in the use of 40K activity per gram of natural potassium. It varies between 27.33 to 31.31 Bq per gram of potassium. The objectives of this study were to independently measure and calculate the 40K activity per gram of natural potassium in an attempt to reduce the uncertainty in the accepted figure. Experimentally the activity of 40K from a known amount of K was determined by measuring the 40K photon emission of an analar grade KCI sample solution and the absolute efficiency of the detection system at energy 1460 KeV. Both the photopeak count-rate and the absolute efficiency were measured using the gamma-ray spectroscopy technique. The 40K activity is also calculated from its half-life (IAEA 1989) and the number of atoms present in the sample. The measured and calculated values obtained were 30.18 ± 0.72 Bq g-1 and 31.00 ± 0.33 Bq g-1 respectively. The difference is of the order of 2.6%. The measured value is consistent with the literature values being close to the mean of the values, namely 29.77. In conclusion, it is believed that the experimental values reported in this work is one of the few experimentally determined results and it is reassuring to note that the experimental and theoretical values are in reasonable agreement.
  4. Abu Bakar Mohamad, Wan Ramli Wan Daud, Amir Kadhum, Fathi Messaud, Mohd. Ambar Yarmo
    Chemical structure of treated and untreated Aciplex membrane has been studied by X-ray Photoelectron Spectroscopy (XPS). Survey spectra showed that both membrane surfaces consist of Fluorine, Carbon, Oxygen, Sulphur and trace of Titanium. Binding energies for the elements are (C1s at 290.6 eV, F1s at 687.5 eV, O1s at 531.3 eV, S2P at 168.1 eV and Ti2P at 454.4 eV). Analysis of narrow scan XPS-spectra of each element demonstrate the presence of (-CF, -CF2, CF3, C-O-C and SO-3) groups, which are in agreement with the structural formula as disclosed by the manufacturer. There is no significant change in chemical states of untreated and treated membrane, which reflect its stability to treatment conditions.
    Struktur kimia Aciplex membran yang sudah dibersihkan dan yang belum dibersihkan telah dikaji menggunakan Spektroskopi Fotoelektron Sinaran-X (XPS). Spektra yang telah ditinjau menunjukkan bahawa kedua-dua permukaan membran mengandungi Florin, Karbon, Oksigen, Sulfur dan sedikit Titanium. Tenaga ikatan bagi unsur-unsur tersebut adalah (C1s pada 290.6 eV, F1s pada 687.5 eV. O1s pada 531.3 eV, S2P pada 168.2 eV dan Ti2P pada 454.4 eV). Analisis imbasan kecil spektra-xps bagi setiap unsur menunjukkan kehadiran kilmpulan (-CF, - CF2, CF3, C-O-C dan SO-3) yang bertepatan dengan formula struktur dari pihak pembekal. Tiada terdapat perubahan nyata berhubung dengan keadaan kimia membran yang sudah dibersihkan dan yang belum dibersihkan yang menggambarkan kestabilannya terhadap keadaan pembersihan.
    MeSH terms: Carbon; Fluorides; Fluorine; Oxygen; Surveys and Questionnaires; Sulfur; Titanium; Disclosure; Physical Phenomena; Photoelectron Spectroscopy; Educational Personnel
  5. Muhamad Mat Salleh, Belal A, Muhamad Yahaya
    There is great interest in gas sensing especially for toxic gases such as carbon monoxide. This paper reports the use of Langmuir-Blodgett films of hematin mixed with arachidic acid to detect carbon monoxide gas in nitrogen at room temperature. The detection was studied based on changes in the optical absorption and reflection of the film using a spectrophotometer and an optical fiber system, respectively. The absorption spectra of a 20 layers LB film decreased when exposed to 10, 100, 1000 ppm CO gas, and had fast recovery time when the gas flow was stopped. An optical fiber system consists of a laser diode as light source, a fiber reflectance probe, thin film sample on a reflecting mirror and a light detector was setup. Using this system it was found that the intensity of the reflected light increased when the film was exposed to the gas. The sensing sensitivity of the films increased after the films were annealed for one hour at 100°C. The result is explained using the atomic force microscope (AFM) images of the LB films taken before and after annealing.
    Terdapat minat yang besar terhadap penderiaan gas terutama bagi gas toksik seperti karbon monoksida. Kertas ini melaporkan penggunaan filem Langmuir-Blodgett (LB) hematin bercampur asid arakidik untuk mengesan gas karbon monoksida dalam gas nitrogen pada suhu bilik. Pengesanan dikaji berasaskan perubahan serapan optik dan pantulan filem yang masing-masing menggunakan spektrofotometer dan satu sistem serat optik. Spektrum serapan bagi 20 lapisan filem LB berkurang apabila filem itu didedahkan kepada 10, 100, 1000 ppm gas CO, dan mempunyai masa pulihan yang pantas apabila aliran gas dihentikan. Satu sistem serat optik yang terdiri daripada satu sumber cahaya diod laser, penduga pantulan, sampel filem nipis di atas satu cermin pemantul dan pengesan cahaya telah dibina. Menggunakan sistem ini didapati keamatan cahaya yang terpantul meningkat selepas filem disempuhlindap selama satu jam pada 100°C. Keputusan ini dijelaskan menggunakan imej mikroskop daya atom (AFM) filem LB yang diambil sebelum dan selepas sempuhlindap.
  6. Ahmad Nazlim Yusoff, Mustaffa Hj. Abdullah
    The a.c. electrical response of a polycrystalline Li0.25Ni0.2Zn0.3Fe2.25O4 ferrite is studied by means of impedance spectroscopy. The impedance measurement was performed at different input voltage amplitudes in ten decades of frequency (1 mHz - 10 MHz). Two overlapping semicircles with negative capacitance phenomenon below 1 Hz are observed at all amplitudes. The two semicircles are mainly attributed to the grain and grain boundary processes at high and low frequencies respectively. The grain boundary impedance shows a non-linear dependence on the input voltage, where the corresponding impedance semicircle is smaller for larger amplitude. However, a linear response is observed for the grain component. The dependence of the a.c. electrical properties of the grain and grain boundary components on the amplitude of the input voltage is discussed.
    Ransangan elektrik a.u. daripada ferit Li0.25Ni0.2Zn0.3Fe2.25O4 berpolihablur dikaji dengan menggunakan spektroskopi impedans. Pengukuran impedans dilakukan pada beberapa amplitud voltan masukan dalam julat sepuluh dekad frekuensi (1 mHz - 10 MHz). Dua lengkung separuh bulatan yang bertindih dengan fenomena kapasitans negatif di bawah frekuensi 1 Hz dapat diperhatikan pada setiap nilai amplitud. Kedua-dua lengkung separuh bulatan tersebut berpunca daripada proses-proses butiran dan sempadan butiran masing-masing pada frekuensi tinggi dan rendah. Impedans sempadan butiran menunjukkan persandaran tak-linear ke atas voltan masukan, dengan separuh bulatan impedans yang berpadanan yang mengecil dengan peningkatan amplitud. Akan tetapi, suatu ransangan linear dapat diperhatikan bagi komponen butiran. Kebergantungan sifat elektrik a.u. bagi komponen-­komponen butiran dan sempadan butiran kepada amplitud voltan masukan dibincangkan.
  7. Supian Bin Samat
    The activity of two liquid mixed radionuclide sources in NPL'S standard glass ampoules were determined by gamma-ray spectrometry measurement using a standard point source placed at 38.5 cm axially above the detector. A radio nuclide 137Cs was chosen, Results obtained were within 3% agreement with the calculated value. The same degree of deviation was obtained when the NPL standard source of equal geometry, chemical composition and density was used.
    Keaktifan dua sumber radionuklid campuran cecair yang terkandung dalam bekas kaca piawai NPL ditentukan dengan kaedah pengukuran spektrometri sinar-gama menggunakan satu sumber titik piawai diletakkan pada 38.5 em di atas pengesan, Satu sumber radionuklid 137Cs dipilih. Keputusan yang diperoleh bersetuju dalam lingkungan 3% dengan nilai yang dikira. Darjah simpangan yang sama diperoleh apabila sumber piawai NPL yang sama dari segi geometri, komposisi kimia dan ketumpatan digunakan,
    MeSH terms: Glass; Radioisotopes; Spectrometry, Gamma
  8. Othman A. Karim, Crapper M, Ali K.H.M.
    The study of cohesive sediment in the laboratory gives rise to a number of instrumentation problems, especially in the location of mud bed, fluid mud and hindered settling layers and in the measurement of flow velocities. This paper describes the application of medical diagnostic ultrasound technique in the cohesive sediment study conducted at the University of Liverpool, United Kingdom. This paper illustrates that the use of ultrasound technique creates a reasonably flexible environment for the study of fluid mud phenomenon in which bed formation and flow velocities can be measured easily, accurately and non-intrusively. This in turn will assist in development of computer models to predict the environmental impact, siltation rates and dredging requirements in both new and existing ports and harbour developments.
    Kajian endapan berjeleket di dalam makmal mengalami pelbagai masalah peralatan, terutamanya bagi menentukan lokasi dasar lumpur, pengenapan terhalang dan pengukuran halaju aliran. Dalam makalah ini diterangkan penggunaan teknologi diagnosis perubatan ultrabunyi dalam kajian endapan berjeleket, yang dijalankan di University of Liverpool, United Kingdom. Ditunjukkan bahawa penggunaan teknologi ultrabunyi keadaan yang begitu boleh suai bagi kajian fenomenon lumpur yang pembentukan dasar dan halaju aliran dapat diukur dengan mudah, tepat dan tanpa gangguan. lni seterusnya dapat membantu di dalam pembangunan model komputer bagi menjangka kesan sekitaran, kadar enapan dan keperluan mengorek bagi pembangunan kawasan pelabuhan baru dan sedia ada.
    MeSH terms: Computers; Environment; Laboratories; Ultrasonography; Transportation Facilities
  9. Abdul Ghani Rafek, Khairuddin Nordin
    The new Genting Sempah tunnel represents an important part of the widening and upgrading of the main east-west road link between Kuala Lumpur on the west coast and Kuantan on the east coast of Peninsular Malaysia. The new tunnel is located between 18m to 30m north of the existing (old) tunnel which was constructed in 1975 and has a similar alignment. Engineering geological investigations and site characterization for the construction of the new tunnel were carried out in 1994 with drilling, aerial photograph interpretation, surface geological mapping, geophysical surveys and laboratory testing. Rock mass classification was carried out based on the Q classification system of Barton et at. (1974). Based on this classification, it was predicted that for the tunnel zone, 8.6 % of the length of the tunnel consisted of rock mass classified as very poor i.e. type two, 82.8% as extremely poor, i.e. type three and the remaining 8.6% as exceptionally poor, i.e. type four. Excavation of the tunnel between March 1995 and September 1996 together with engineering geological logging and rock mass classification revealed the following; type two, very poor 6.3%, type three, extremely poor 89.9%, type four, exceptionally poor 3.8%. These results show the general validity of the prediction of the rock mass quality.
    Terowong kedua Genting Sempah merupakan suatu bahagian utama dalam pembesaran dan peningkatan taraf jalan timur-barat utama yang menghubungi Kuala Lumpur di pantai barat dan Kuantan di pantai timur Semenanjung Malaysia. Terowong kedua berkedudukan 18 m hingga 30 m ke utara terowong lama yang dibina pada tahun 1975 dan mempunyai penjajaran yang sama. Penyiasatan geologi kejuruteraan dan pemeriksaan tapak pembinaan terowong kedua dilaksanakan pada tahun 1994 dengan penggerudian, pentafsiran fotograf udara, pemetaan geologi permukaan, survei geofizik dan ujian makmal. Pengelasan kualiti jasad batuan dilakukan berdasarkan sistem pengelasan Q oleh Barton et al. (1974). Hasil pengelasan ini di zon terowong meramalkan 8.6% panjang terowong baru terdiri daripada jasad batuan berkualiti sangat rendah, iaitu jenis dua, 82.8% berkualiti tersangat rendah, iaitu jenis tiga manakala 8.6% panjang terowong terdiri daripada jasad batuan berkualiti luarbiasa rendah, iaitu jenis empat. Penggalian terowong di antara Mac 1995 dan September 1996 dengan rakaman geologi kejuruteraan dan pengelasan jasad batuan semasa penggalian menghasilkan keputusan seperti berikut; jenis dua, berkualiti sangat rendah 6.3%, jenis tiga, berkualiti tersangat rendah 89.9%, jenis empat, berkualiti luar biasa rendah 3.8%. Keputusan
    MeSH terms: Azepines; Geology; Malaysia; Surveys and Questionnaires; Thiocarbamates; Macrophage Activation Syndrome
  10. Umar Hamzah, Abd. Rahim Samsudin
    Identification of a possible source of engineering geological hazard in the limestone area such as cavities, sinkholes and an underground cavern have become necessity for site investigation before any construction of roads, bridges and buildings are carried out. The study is also necessary for tunneling and underground mining works where knowledge of the engineering properties of the rock mass is very important in order to assess the suitability and safety of a proposed building. Geophysical techniques have been widely used in engineering geological study to deal with such problems that normally arise at construction sites with limestone bedrock. In this study, shallow seismic reflection technique and dipole-dipole geoelectrical methods were used to detect the presence of cavity in lime stone area of Batu Cave, Kuala Lumpur. The exact location and depth of cavities in the area were determined from the existing borehole data and report provided by the Geological Survey Department of Malaysia. Based on the borehole data, several cavities that were filled-up with water and fine silt are encountered at depths of 15.7m to 17.8m, 20.2m to 21.1m and 21.4m to 25.7m. Three shallow seismic reflection profiles were established on the cavity area and the results show that the cavities in the limestone occur in the form of 20 to 30m long subterranean channel of 15 to 30 m depth. Dipole-dipole resistivity survey conducted on seismic lines one and three also indicates the presence of the channel and cavities in the limestone.
    Pengecaman punca bencana geologi kejuruteraan di kawasan batu kapur seperti lohong batu kapur, kewujudan lubang benam dan gua-gua batu kapur telah menjadi amat penting dalam penyiasatan tapak sebelum sesuatu pembinaan seperti jalan raya, jambatan dan bangunan dilakukan. Begitu juga dalam kerja-kerja penerowongan dan perlombongan, pengetahuan asas sifat kejuruteraan jasad batuan amat perlu diketahui untuk menitai kesesuaian dan keselamatan bangunan yang bakal dibina. Teknik geofizik telah digunakan secara meluas dalam kajian geologi kejuruteraan untuk menangani masalah yang terdapat di tapak-tapak binaan yang mempunyai batu kapur sebagai batuan dasar. Dalam kajian ini teknik seismos pantulan cetek dan kaedah geoelektrik dwikutub-dwikutub telah digunakan untuk mengesan rongga batu kapur yang terdapat di kawasan Batu Caves, Kuala Lumpur. Kedudukan dan kedalaman rongga batu kapur di kawasan kajian telah ditentukan melalui data lubang gerudi dan laporan yang diperoleh daripada Jabatan Kajibumi Malaysia. Berdasarkan data lubang gerudi tersebut terdapat beberapa rongga yang terisi air dan pasir halus berlodak di kedalaman 15.7 m hingga 17.8 m, 20.2 m hingga 21.1 m dan 21.4 m hingga 25.7 m. Tiga profil seismos pantulan cetek telah dibuat di kawasan berongga tersebut dan hasil survei menunjukkan rongga dalam batu kapur tersebut membentuk palung sepanjang hampir 20 - 30 m pada kedalaman antara 15 m hingga 30 m. Rentisan survei geoelektrik dwikutub yang dilakukan pada profil seismos satu dan tiga juga memperlihatkan kehadiran lohong dan palung dalam batu kapur tersebut.
    MeSH terms: Azepines; Calcium Carbonate; Composite Resins; Geology; Malaysia; Surveys and Questionnaires; Thiocarbamates; Water; Caves
  11. Syakirah Samsudin, Zubaid A.
    Space use and activity patterns by 3 species of small mammals, namely, Tupaia glis, Callosciurus notatus and e. nigrovitatus were determined. The home range size of T. glis ranged from 9,544 to 73,470m2, C. notatus from 6,512 to 16,150m2 and C. nigrovitatus 10,970m2. There was no overlap in the ranges between individuals of the same species and sex but the ranges of different species overlapped. There was no significant difference in the mean daily distance moved among the studied individuals. All individuals showed a bimodal type of activity pattern.
    Penggunaan habitat dan corak aktiviti 3 spesies mamalia kecil, Tupaia glis, CalJosciurus notatus dan C. nigrovitatus telah ditentukan. Saiz banjaran kediaman T. glis adalah antara 9,544 hingga 73,470m2, C. notatus daripada 6,512 hingga 16,150m2 dan C. nigrovitatus 10,970m2. Pertindihan banjaran tidak wujud antara spesies atau jantina yang sama. Walau bagaimanapun, berlaku pertindihan banjaran antara spesies yang berbeza. Tiada perbezaan bererti pada purata jarak yang dilalui setiap hari antara individu-individu yang dikaji. Semua individu yang dikaji menunjukan corak aktiviti jenis bimodal.
    MeSH terms: Animals; Homing Behavior; Mammals; Sciuridae; Tupaia; Ecosystem; Myoxidae
  12. Suriah Abdul Rahman, M. Shamsoul Bahrein, Tew WA, Babji A
    A total of 13 samples of sausages were analyzed for proximate composition and mineral (sodium, calcium, potassium, phosphorus and iron) content. The sausages were of UKM formulation, local brand and imported brand. Results from proximate analyses indicated water content ranged between 58.18­-71.30g/100g, protein 11.4-16.52g/100g, fat 8.19-22.87g/100g, carbohydrate 2.00-10.2g/100g, ash 1.52-2.99g/100g and fiber 0.69-2. 199/100g. In comparing the three groups of sausages no significant differences were found for water, fat and carbohydrate contents, while the ash and protein contents of the local brand were lower (p<0.05) compared to the other two formula­tions. UKM formulated sausages contain the least fibre. Overall the average values for sodium and phosphorus of local brand sausages were found to be lowest while calcium, potassium and iron were lowest for UKM formulated sausages.
    Tiga belas jenis sosej ayam telah dianalisis untuk komposisi proksimat dan kandungan mineral (natrium, kalsium, kalium, fosforus, ferum). Sosej ini ialah sosej formulasi UKM, sosej tempatan dan sosej import. Dari keputusan analisis proksimat, didapati kandungan air berjulat di antara 58.18-71.30g/ 100g, protein 11.4 -16.52 g/100g, lemak 8.19-22.87g/100g, karbohidrat 2.00­-10.2g/100g, abu 1.52-2.99g/100g dan gentian 0.67-2.19g/100g. Apabila dibandingkan di antara tiga kumpulan sosej didapati tiada perbezaan bererti (p<0.05) bagi air, lemak dan karbohidrat sementara kandungan abu dan protein sosej tempatan adalah terendah berbanding sosej formulasi UKM dan import. Manakala bagi kandungan gentian pula, sosej formulasi UKM adalah paling rendah. Secara keseluruhan, purata kandungan mineral natrium dan fosforus didapati paling rendah bagi sosej tempatan manakala kandungan kalsium, kalium dan ferum pula adalah terendah bagi sosej formulasi UKM.
  13. Kamarulzaman Bin Ibrahim, Abdul Aziz Jermain
    Dengue is one of the main factors of mortality of inhabitants in the region of South East Asia. Malaysia is one of the countries which is facing a high incidence of dengue, particularly in the 70's and early 80's. The Ministry of Health has taken various measures in order to reduce the dengue epidemic. These include educating people about dengue and conducting research such as investigation of factors that influence the epidemic of dengue. In this study, a sequential Bayesian approach is applied to data of the proportion of death due to dengue over the period from 1982 to 1992. In the sequential Bayesian approach, the data for the year 1982 becomes the prior information for the 1983 data and so on. The data for the different periods are combined in a chronological manner until the final posterior distribution of the proportion of death due to dengue is obtained. It is found that the overall proportion is 0.59% and its standard deviation is 0.00002%.
    Denggi adalah satu daripada faktor utama kematian bagi penduduk di rantau Asia Tenggara. Malaysia pula merupakan satu daripada negara yang sedang mengalami kadar insiden denggi yang tinggi, khususnya dalam tahun 70-an dan pada awal 80-an. Kementerian Kesihatan telah mengambil pelbagai langkah untuk mengurangkan wabak denggi. Ini termasuk memberikan pendidikan tentang denggi dan membuat kajian tentang faktor-faktor yang mempengaruhinya. Dalam kajian ini kaedah Bayesan jujukan digunakan terhadap data perkadaran yang mati akibat denggi dalam tempoh 1982 hingga 1992. Dalam kaedah ini, data tahun 1982 digunakan sebagai maklumat prior untuk data tahun 1983 dan seterusnya. Data dari tahun yang berlainan digabungkan secara kronologi sehingga diperoleh taburan posterior yang terakhir bagi perkadaran yang mati akibat denggi. Didapati bahawa perkadaran keseluruhan ialah 0.59% dan sisihan piawainya 0.00002%.
    MeSH terms: Asia; Asia, Southeastern; Bayes Theorem; Dengue; Malaysia; Incidence; Epidemics
  14. Md. Nasir Bin Sulaiman, Evans D
    NEUCOMP2 is a parallel Neural Network Compiler for a shared-memory parallel machine. It compiles a program written as a list of mathematical specifications of Neural Network (NN) models and then translates it into a chosen target program which contains parallel codes. In this paper we present the performance results for intertwined spiral problem on popular NN models. The models are the Backpropagation, Kohonen, and Counter propagation models. NEUCOMP2 was developed on the Sequent 8000 computer system at PARC.
    NEUCOMP2 adalah Pengkompilasi Rangkaian Neuron selari untuk mesin selari berkongsi-ingatan. Ia mengkompilasi atur cara yang ditulis dalam bentuk senarai spesifikasi matematik bagi model Rangkaian Neuron (RN) dan kemudian menterjemahkannya kepada atur cara sasaran yang dipilih mengandungi kod-kod selari. Dalam makalah ini dibentangkan keputusan prestasi penyelesaian masalah lingkaran berkembar menggunakan model­-model RN tertentu. Model-model ini adalah model rangkaian Perambatan Balik, Kohonen, dan Lawan Perambatan. EUCOMP2 dibangunkan pada sistem komputer Sequent 8000 di PARC.
  15. Aziz Bin Deraman, Ahmad Shukri Bin Yahaya
    A study was conducted to examine the usage of application software and its development practices in Malaysia. The study has shown that the use of application software is greatly emphasized by organizations in their respective businesses. And for most organizations, the application software is supplied by a vendor or through in house development. For the software development practices, the deployment of a current technique and technology is still inadequate. Therefore, most of the existing information technology practitioners should be given additional training on the latest techniques of software development. Other aspect of improvement on software development practices is also discussed.
    Satu kajian terhadap status pemakaian dan kegiatan pembangunan perisian gunaan di Malaysia telah dijalankan. Kajian ini menunjukkan yang aspek pemakaian sangat diberi penekanan oleh organisasi. Manakala proses perolehan perisian gunaan pula terbahagi secara setara di antara buat sendiri dengan menggunakan pihak ketiga. Namun begitu yang ketara ialah kadar penggunaan teknologi dan teknik terkini dalam kegiatan pembangunan perisian masih berkurangan. Oleh itu disarankan supaya aspek latihan teknik kakitangan teknologi maklumat organisasi perlu dipertingkatkan secara berterusan. Di samping itu kajian ini memaparkan beberapa aspek amalan pembangunan perisian yang boleh diperbaiki lagi.
    MeSH terms: Commerce; Information Science; Malaysia; Software; Technology
  16. Azizah Hashim, Mohd. Imran Khan, Rizainal Mustaffa
    Peanut (Acrachis hypogea L.) var. Matjam grown in an Ultisol obtained from peanut field, was respectively inoculated with Glomus mosseae and G. velum. Responses of the host plant to treatments was estimated by periodic measurements from the fourth to twelfth weeks, for dry shoot and root weight, nodulation, N2 fixation (C2H2 reduction activity), per cent root colonization and vesicle formation cm-1 root. A proportionate increase in dry weight of root and shoot was observed with increase in sampling time up to the eight and tenth weeks, respectively. This increase was only significant only in the 10th week for shoot and 8th week for dry weights when compared to that of uninoculated control plants (indigenous species only present). However, the difference between the two Glomus species was not a significant for all the samplings. The nodule number plant-1 and N2 fixation was maximum and significant in the 8th week when compared to uninoculated controls. How­ever, there was a sharp decline in nodulation and N2 fixation in both the treated and uninoculated plants after this week. This decrease was significant (P < 0.05) in G. mosseae treatment (at the 12th week for nodulation and 10th - 12th week for N2 fixation). The difference between G. mosseae and G. velum was not significant (except, in the 8th and 12th week) for N2 fixation. Percentage root colonization and formation of vesicle cm-1 root system was significantly higher in G. mosseae and G. velum plants compared to controls. However, the formation of vesicle was not significantly different at 12th week of observation. Plant responded positively to G. mosseae by forming more vesicle than in G. velum or indigenously colonized plants.
    Kacang tanah (Arachis hypogea L.) ver. Matjam telah ditanam pada tanah ultisol yang diambil dari ladang bekas ditanam dengan kacang tanah. Tanah ini diinokulat dengan Glomus mosseae dan G. velum. Tindakbalas tanaman perumah terhadap rawatan telah dinilai dalam jangkamasa empat hingga 12 minggu. Pengambilan data berdasarkan kepada berat kering pucuk, berat akar, bilangan nodul, peningkatan N2 (aktiviti penurunan (2H), peratus kolonisasi akar dan pembentukan vesikul per cm akar. Pembandingan pertambahan bagi berat kering akar dan pucuk dinilai dengan peningkatan masa persampelan dari minggu ke 8 hingga minggu ke 10. Peningkatan ini memberikan nilai bererti hanya pada minggu ke 10 bagi pucuk dan minggu ke 8 bagi berat kering berbanding dengan pokok kawalan yang tidak dinokulat (hanya mengandungi spesies asal). Walau bagaimanapun perbezaan antara dua spesies Glomus tidak bererti pada semua sampel. Bilangan nodul per pokok dan pengikat N2 adalah maksima dan bererti pada minggu ke 8 apabila dibandingkan dengan kawalan (tidak diinokulan). Walau bagaimanapun terdapat penurunan yang ketara pada penodulan dan peningkatan N2 pada kedua-dua pokok rawatan dan yang tidak diinokulat. Penurunan ini bererti (P < 0.05) pada rawatan G. mosseae (pada minggu ke 12 bagi penodulan dan minggu ke 10 hingga minggu ke 12 bagi pengikatan N2) Perbezaan antara G. mosseae dan G. velum tidak bererti (kecuali pada minggu ke 8 dan 12) bagi pengikatan N­2. Peratusan kolonisasi akar dan pembentukan vesikul per cm adalah sangat bererti pada tanaman G. mosseae dan G. velum berbanding dengan kawalan. Walau bagaimanapun pembentukan vesikul tidak mempunyai perbezaan bererti pada minggu ke 12. Tanaman memberi kesan yang positif kepada G. mosseae dengan pembentukan lebih banyak vesikul berbanding kepada G. velum atau pada tanaman yang hanya mempunyai spesies asal (kawalan).
  17. Mustaffa Hj. Abdullah, Tan TK
    Samples of Y-Ba-Cu-O superconductor with nominal compositions of YBa2Cu3O7-d + x (weight %) Y2O3 (x = 0 - 15) were prepared by solid state reaction method using the Y2Cu2O5 and BaCuO2 precursors as the starting reagents. The X-ray diffraction (XRD) diffractograms for the doped samples (x> 0) show an additional non-superconducting Y2BaCuO5 (211) phase. The scanning electron microscope (SEM) micrographs show that the smaller Y2BaCuO5 grains are precipitated on the surface of the larger YBa2Cu3O7-d (YBCO) crystals. The grain size of the YBCO decreases with increasing yttria. The superconducting zero resistivity critical temperature (Tco) of the doped samples is very close to the Tco of the YBCO for x < 5, but it seems to be significantly decreasing for larger x. The transport critical current density (J) for x < 5 is enhanced due to magnetic flux pinning process by the 211 phase. However, Jc decreased for larger x due to the increase of weak links at the grain boundaries of the YBCO phase.
    Sampel superkonduktor Y-Ba-Cu-O dengan komposisi nominal YBa2Cu3O7-d + x (% berat) Y2O3 (x = 0 -15) disediakan dengan kaedah tindakbalas keadaan pepejal menggunakan bahan pelopor Y2Cu2O5 dan BaCuO2 Difraktogram pembelauan sinar-X (XRD) bagi sampel yang didop (x > 0) menunjukkan wujudnya fasa tak mensuperkonduksi Y2BaCuO5 (211). Mikrograf mikroskop imbasan elektron (SEM) menunjukkan bahawa butiran Y2BaCuO5 yang lebih kecil itu termendap di atas permukaan hablur YBa2Cu3O7-d yang lebih besar. Saiz hablur YBCO mengecil dengan peningkatan yittria. Suhu genting kerintangan sifar (Tc) bagi sampel yang didop adalah hampir dengan Tco bagi YBCO untuk x<5, tetapi menurun dengan agak cepat untuk x yang lebih besar. Ketumpatan arus genting angkutan (J) untuk x < 5 meningkat jika dibandingkan dengan YBCO disebabkan oleh proses kepinan fluks magnet oleh fasa 211. Walau bagaimanapun, Jc menurun untuk x yang lebih tinggi kerana meningkatnya hubungan lemah pada sempadan butiran fasa YBCO.
    MeSH terms: Body Weights and Measures; Copper; Indicators and Reagents; Microscopy, Electron, Scanning; Temperature; X-Ray Diffraction; Yttrium; Barium Compounds; Magnets; Superconductivity
  18. Mohd. Nasir Saadon, Camerlengo AL, Wan Hazli Wan Kadir
    This study provides new information on the coastal current along the northern region of the east coast of Peninsular Malaysia. A self-recording S4 current meter, 3 m deep, from July to September 1996, about one nautical mile from the coastline of Kuala Terengganu, was used to determine the speed and direction of the coastal current. The results confirm the pres­ence of coastal current along the northern region of the east coast of Peninsular Malaysia, during the southwest (SW) monsoon season. The coastal current has a maximum speed of over 30 cm/s. Its direction off low is affected by tide. It flows northward (southward) during ebb (flood) tide. However, its net direction of flow is southeastward.
    Kajian ini memberikan maklumat baru arus pantai di sepanjang bahagian utara Pantai Timur Semenanjung Malaysia. Meter arus rekod sendiri S4, telah dipasangkan di kedalaman 3 m, dari Julai hingga September 1996, lebih kurang satu batu nautika dari pantai Kuala Terengganu, untuk menentukan halaju dan arah arus pantai. Hasil kajian ini mengesahkan kehadiran arus pantai di sepanjang bahagian utara pantai timur Semenanjung Malaysia, dalam monsun barat daya. Arus pantai mempunyai halaju maksimum melebihi 30 cm/s. Arahnya dipengaruhi oleh air pasang surut. Ia mengalir ke utara (selatan) ketika air surut (pasang). Walau bagaimanapun, pengaliran bersihnya adalah ke arah tenggara.
  19. Shahidan Radiman
    The evolution of microemulsion microstructure formed from didodecyl dimethyl ammonium bromide, water and cyclohexane which started from being structureless (fiat scattering profile) to a mean-field Ginsburg-Landau behaviour is shown. The evolution gave the characteristic Lorentzian scattering profile as the system approaches phase separation.
    Evolusi mikrostruktur mikroemulsi yang terbentuk daripada didodesil dimetil ammonium bromida, air dan sildoheksana tiada berstruktur (profil serakan yang malar) kepada medan-min Ginsburg-Landau. Evolusi tersebut memberikan serakan Lorentz apabila komposisinya menghampiri sempadan pemisahan fasa.
    MeSH terms: Quaternary Ammonium Compounds; Bromides; Composite Resins; Cyclohexanes; Water; Ammonium Compounds
  20. Lalang Buana, Ahmad Mahir Razali, Zainodin Haji Jubok
    The changes on the vegetables oil trading environment might change the foundation of palm oil pricing and induce a structural change to the price model. Failing to take it account the structural change in a data series might lead to misspecification of the actual model. This study, however, showed that structural change was not present in the monthly, January 1983 to July 1995, palm oil price, but it was present on the unconditional variance. The underlying model of this series was ARIMA (3, 1, 0) with ARCH (1). The critical change of the unconditional variance took place in April 1989.
    Perubahan dalam suasana perdagangan minyak sayuran boleh mengubah asas harga minyak kelapa sawit. Seterusnya ia merangsang perubahan dalam struktur model harga minyak tersebut. Kegagalan untuk mengambil kira perubahan struktur dalam siri data menjadikan model itu tidak menepati spesifikasi daripada model sebenar. Kajian ini mendapati bahawa perubahan struktur tidak berlaku bagi data harga minyak sawit dari Januari 1983 hingga Julai 1995. Tetapi perubahan berlaku pada varians tidak bersyaratnya. Model asas bagi siri ini adalah ARIMA (3,1,0) dengan ARCH(1). Didapati juga bahawa perubahan yang kritikal bagi varians tidak bersyarat berlaku pada bulan April 1989.
    MeSH terms: Commerce; Costs and Cost Analysis; Environment; Plant Oils; Vegetables; Moclobemide
External Links