bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of SEBS on Impact Strength and Flexural Modulus of Polystyrene/Polypropylene Blends
Authors: Samsudin Sani Amril , Hassan Azman , Mokhtar Munirah , Syed Jamaludin Syed Mustafa
Published: January 2013

Pengadunan polistirena (PS) dengan polipropilena (PP) dibangunkan dengan objektif untuk mengatasi masalah kerapuhan PS dan meningkatkan kekuatan hentaman pada suhu bilik. Walau bagaimanapun, pengadunan PS dan PP adalah tidak serasi. Kajian terdahulu menunjukkan bahawa koâ€“polimer blok seperti stirenaâ€“b â€“(etilenaâ€“coâ€“ butilena)â€“bâ€“stirena (SEBS) adalah agen penyerasi yang baik bagi adunan PS/PP ini. Kajian ini juga menyelidiki kegunaan SEBS dalam meningkatkan keserasian adunan PS/PP. Mesin penyemperit skru berkembar Brabender PL2000, digunakan untuk melakukan adunan PS/PP pelbagai komposisi dalam julat 90â€“60% PS yang mengandungi kandungan SEBS yang berbeza dalam julat 5â€“25 phr, dan diacuâ€“suntikan bagi menentukan sifat mekanikal. Keputusan yang didapati daripada sifat mekanikal menunjukkan peningkatan sifat adunan yang menunjukkan kesan penyerasian dalam sistem adunan. Penambahan SEBS telah meningkatkan kekuatan hentaman adunan tetapi mengurangkan kekuatan dan modulus lenturan. Adunan 90/10 PS/PP dengan 25 phr SEBS menunjukkan kekuatan hentaman yang unggul. Yang menarik, keputusan menunjukkan bahawa SEBS lebih berkesan pada kandungan PP yang rendah.

Kata kunci: PS; PP. SEBS; sifat mekanikal; adunan polimer

Blends of Polystyrene (PS) with Polypropylene (PP) were developed with the objective to overcome the inherent brittleness of PS and enhance the impact strength at room temperature. However, the blends of PS and PP were known to be immiscible. Previous studies have concluded that the block copolymer such as styreneâ€“bâ€“ (ethyleneâ€“coâ€“butylenes)â€“bâ€“styrene (SEBS) is good compatibiliser for this PS/PP blends. The present study investigates the use of SEBS as a compatibiliser in this immiscible blend system. Using a Brabender PL2000 twinâ€“screw extruder, blends of PS/PP in various composition range of 90â€“60 wt% PS containing different amount of SEBS in the composition range of 5â€“25 phr were prepared and injection molded to evaluate for mechanical properties. The results obtained from mechanical properties show some improvement in the properties of the blends indicating some compatibilisation effect in the blend system. The addition of SEBS enhanced the impact properties of the blends but reduced the flexural strength and flexural modulus. The blends of 90/10 PS/PP with 25 phr SEBS gave superior impact properties. Interestingly, the results show that SEBS is more effective at lower PP content.

Key words: PS; PP; SEBS; mechanical properties; polymer blends
A Potential Use of Dehalogenase D (DehD) from Rhizobium sp. for Industrial Process
Authors: Huyop Fahrul Z. , Cooper Ronald A.
Published: January 2013

-2-haloacid and the kinetic data of DehD hold promise for further development to be used in an industrial process.

Key words: Dehalogenase; DehL; DehD; Rhizobium
Effect of Ammonium Sulphate on the Sporulation of Bacillus thuringiensis subsp. aizawai SN2 (a Local Isolate) during Batch Fermentation
Authors: Wan Yusoff Wan Mohtar , Mohd. Masri Mohd. Mazmira , Chan Choy Mei
Published: January 2013

Kesan penambahan ammonium sulfat, (NH4)2SO, (sebagai sumber nitrogen bukan organik tunggal) terhadap pensporaan Bacillus thuringiensis subsp. aizawai strain SN2 dalam kultur kelompok telah dikaji. Peratus spora tertinggi (76 %) dikesan selepas 96 j pengkulturan dalam medium yang mengandungi 1.5 gL-1 (NH4)2SO4. Peratus spora tertinggi sebanyak 82 % juga dikesan dalam sampel 96 j apabila medium yang mengandungi 1.5 gL-1 (NH4)2SO4 ditambah dengan 3.0 gL-1 (NH4)2SO4 pada jam keenam selepas mula fermentasi. Peningkatan peratus spora didapati tidak berkaitan dengan jumlah kandungan nitrogen tetapi berkaitan dengan masa penambahan sumber nitrogen.

Kata kunci: Bacillus thuringiensis subsp. aizawai strain SN2, masa penambahan nutrien, kultur kelompok

The effect of ammonium sulphate (as the sole inorganic nitrogen source) on the sporulation of Bacillus thuringiensis subsp. aizawai strain SN2 was investigated in batch fermentation. The spore percentage of 76 % was achieved at 96 h after inoculation into a medium containing initial cencentration of 1.5 gL-1 ammonium sulphate. In another experiment, the maximum spore percentage of 82 % was obtained after 96 h inoculation in a medium with initial concentration of 1.5 gL-1 (NH4)2SO4 followed by an addition of 3.0 gL-1 (NH4)2SO4 after 6 h of fermentation. The increase in Bacillus thuringiensis spore percentage was not a function of total nitrogen content in the medium but was a function of the time nitrogen being added.

Key words: Bacillus thuringiensis subsp. aizawai strain SN2, timing addition, batch fermentation
Free Convection Boundary Layer Over a Nonisothermal Vertical Flat Plate
Authors: Nazar Roslinda , Amin Norsarahaida
Published: January 2013

Penyelesaian berangka bagi masalah lapisan sempadan olakan bebas terhadap plat menegak dengan taburan suhu atau fluks haba yang ditetapkan akan dibincangkan. Perbincangan tertumpu kepada dua jenis syarat sempadan iaitu, variasi sinusoid suhu dinding dan variasi eksponen fluks haba. Dalam kajian ini, pengiraan berangka dilakukan menggunakan suatu skema beza terhingga tersirat yang efisien, yang dinamakan kaedah kotak Keller. Ilustrasi pengiraan dijalankan dan keputusan baru yang diperolehi dibandingkan dengan keputusan-keputusan lepas yang diperolehi menggunakan kaedah-kaedah penyelesaian yang lain, dan didapati bahawa hasil perbandingan adalah baik. Perbandingan melibatkan kecerunan suhu tak berdimensi bagi variasi sinusoid suhu dinding dan suhu tak berdimensi bagi variasi eksponen fluks haba. Keputusan baru bagi variasi tegasan ricih permukaan dengan pelbagai nombor Prandtl juga dibincangkan. Di samping itu, bagi kes variasi sinusoid suhu dinding, profil halaju dan suhu diberikan bagi beberapa nombor Prandtl iaitu 0.7, 1, 10 dan 100, manakala bagi kes variasi eksponen fluks haba, profil halaju dan suhu juga diketengahkan untuk beberapa nilai koordinat mengikut-strim yang terjelmakan ξ iaitu 0, 1, 10 and 100.

Kata kunci: Olakan bebas; lapisan sempadan; plat menegak tak isoterma; kaedah berangka

Numerical solutions are presented for the free convection boundary layer problems on a vertical flat plate with prescribed temperature or heat flux distributions, namely the sinusoidal wall temperature and the exponential heat flux variations. The numerical computation is carried out using a very efficient implicit finite difference scheme known as the Keller-box method. Illustrative computational examples are carried out and the present results are compared with previously available theoretical results obtained using other methods of solution, and they are found to be in good agreement. Comparisons of nondimensional temperature gradient for sinusoidal wall temperature variation and of nondimensional wall temperature with exponential variation in wall heat flux are made between the present and previous results. New results for the variation of the surface shear stress with various Prandtl numbers are also presented. In addition, for the case of sinusoidal wall temperature variation, representative velocity and temperature profiles are presented for Prandtl numbers 0.7, 1, 10 and 100, while for the case of exponential heat flux distribution, the velocity and temperature profiles for various transformed streamwise coordinate ξ = 0, 1, 10 and 100 are illustrated.

Key words: Free convection; boundary layer; nanoisothermal vertical plate; numerical method
Satu Pendekatan bagi Membangunkan Peralatan Pemarkahan Esei Berkomputer
Authors: Mohd Zin Abdullah , Darus Saadiyah , Mat Kassim Norhayati
Published: January 2013

Kertas ini membincangkan satu pendekatan bagi membangunkan satu peralatan pemarkahan esei secara automatik. Peralatan pemarkahan ini telah diimplementasi dan diintegrasikan ke dalam CMS (Coursework Management System), satu sistem pengurusan kerja kursus yang telah dibangunkan di Universiti Kebangsaan Malaysia. Kertas ini dimulakan dengan membincangkan kaedah pemarkahan esei yang biasa digunakan oleh pensyarah dan sistem pemarkahan esei secara automatik yang sedia ada, diikuti dengan perbincangan tentang reka bentuk dan implementasi peralatan pemarkahan ini. Kertas ini menunjukkan bahawa satu pendekatan mudah bagi membangunkan peralatan pemarkahan ialah dengan menggunakan peralatan perisian sedia ada, misalnya peralatan perisian yang disediakan oleh Microsoft Word. Namun begitu, disebabkan peralatan perisian yang disediakan oleh Microsoft Word hanya menyokong Bahasa Inggeris, hanya esei dalam Bahasa Inggeris sahaja yang dapat dimarkahkan oleh peralatan pemarkahan ini.

Kata kunci: Pemarkahan esei, sistem pengurusan tugasan, peralatan perisian, peralatan pemarkahan, penilaian pembelajaran

This paper discusses an approach of developing a computer-based essay-marking tool. The marking tool has been implemented and integrated into CMS (Coursework Management System), a coursework management system that has been developed at Universiti Kebangsaan Malaysia. The paper will first discuss methods that lecturers normally used in marking essays and available automated essay marking systems, followed by a discussion on the design and implementation of the marking tool. This paper shows that a simple possible approach in developing a marking tool is by using available software tools, such as software tools that are provided by Microsoft Word. However, since software tools provided by Microsoft Word can only support the English language, this marking tools can only mark essays that are written in English.

Key words: Essay marking, coursework management system, software tool, marking tool, learning assessment
Diagnosis Kerosakan Litar Menggunakan Pspice dan Rangkaian Neural Tiruan
Authors: Jasni Jasronita , Mohd Noor Samsul Bahari , Abd Rahman Ribhan Zafira
Published: January 2013

Kerosakan komponen di dalam satu litar sangat sukar dikesan dan mengambil masa yang lama untuk dikenalpasti. Kertas ini membentangkan kaedah mendiagnosis kerosakan litar menggunakan Rangkaian Neural Tiruan (RNT). Litar Pengayun dan Pulse Width Modulator yang merupakan sebahagian dari Switch Mode Power Supply telah digunakan sebagai litar kajian. Litar ini disimulasi menggunakan Pspice dan data voltan pada nod direkodkan dan digunakan dalam sistem rangkaian neural tiruan. Setelah dilatih, sistem ini berupaya mengenalpasti komponen yang rosak dengan mudah.

Kata kunci: Diagnosis kerosakan, litar analog, rangkaian neural

Faulty components in a circuit is difficult and time consuming to be identified. This paper presents a method of circiut fault diagnosis using artificial neural networks (ANN). Oscillator circuit with Pulse Width Modulator which is part of a Switch Mode Power Supply is used in this study. The system is trained and able to identify the individual faulty components with ease.

Key words: Fault diagnosis, analog circuit, neural network
Optimization of Oxidative Coupling of Methane Using Response Surface Methodology
Authors: Saidina Amin Nor Aishah , Zakaria Zaki Yamani
Published: January 2013

Tindak balas penggandingan beroksida metana (OCM) terhadap mangkin Li/MgO dioptimumkan menggunakan reka bentuk eksperimen daripada perisian Statsoft Statistica versi 6.0. Pemboleh ubah yang di pilih dalam kajian ialah suhu operasi, jumlah kadar aliran suapan per berat mangkin (F/W), dan peratus berat Li yang dimasukkan ke dalam mangkin MgO, manakala penukaran metana, kememilihan C2, dan keberhasilan C2 merupakan sambutannya. Model persamaan diuji menggunakan analisis Anova dengan 99% darjah keyakinan. Metodologi sambutan permukaan (RSM) digunakan bagi menentukan sambutan optimum. Dengan menggunakan analisis varians dan eksperimen tambahan, kejituan model dapat disahkan.

Kata kunci: OCM, pengoptimuman, reka bentuk eksperimen, metodologi sambutan permukaan

Oxidative Coupling of Methane (OCM) reaction over Li/MgO catalyst was optimized using experimental design from Statsoft Statistica version 6.0 software. The manipulated variables chosen in this study were operating temperature, total flow rate per weight of catalyst (F/W), and weight percent of Li doped into MgO catalyst, whilst methane conversion, C2 product selectivity, and C2 product yield were the responses. The equation model was tested with Anova analysis with 99% degree confidence. The Response Surface Methodology (RSM) was employed to determine the optimum responses. By means of variance analysis and additional experiments, the adequacy of this model was confirmed.

Key words: OCM, optimization, experimental design, response surface methodology
Assessing Inherent Health Hazard for Proposed Plants
Authors: Mimi H.
Published: January 2013

Pada peringkat awal reka bentuk loji kimia, keputusan paling penting dan kritikal yang perlu dibuat adalah ketika pemilihan proses kimia yang bakal digunakan untuk penghasilan produk yang dikehendaki. Sebelum ini, ekonomi merupakan faktor yang diberi keutamaan dalam pemilihan proses kimia yang terbaik. Sebaliknya kini, faktor kesihatan, keselamatan serta alam sekitar merupakan isu penting yang menjadi tumpuan dan amat dititikberatkan dalam pengoperasian sesebuah loji. Risiko ke atas kesihatan para pekerja di kawasan loji berikutan terdedah kepada bahan–bahan kimia di tempat kerja dapat dikurangkan melalui pemilihan proses kimia yang betul. Proses yang paling ‘sihat’ dapat dikenal pasti dengan menjumlahkan ancaman ke atas kesihatan manusia. Dalam projek ini, PRHI telah diperkenalkan untuk menjangka potensi ancaman proses kimia ke atas kesihatan pekerja. Proses alternatif yang wujud bagi menghasilkan produk yang sama akan disusun berdasarkan tahap kesihatan yang dihasilkan oleh setiap proses. Lebih tinggi nilai indeks yang diperolehi, maka lebih berbahayalah sesuatu proses itu. Nilai PRHI dikira berdasarkan pelepasan bahan kimia serta kuantiti bahan kimia yang dihidu oleh pekerja. Indeks yang telah dibangunkan dalam projek ini diaplikasikan ke atas enam proses kimia alternatif yang wujud bagi menghasilkan metil metakrilat (MMA). Keputusan bagi pengiraan PRHI ini kemudiannya dibandingkan dengan Inherent Safety Index (ISI), Environmental Hazard Index serta kos penghasilan produk bagi kesemua enam proses alternatif.

Kata kunci: ISHE, teknik penilaian keselamatan loji

Proper selection of chemical process route is one of the main design decisions during the preliminary stages of chemical plant design. Previously, the most important factor for selecting the best chemical process route was only the economics. But now, safety, environmental and health issues have become important factors to be considered. Health risks on workers could also be reduced by proper selection of chemical process route. However, the health hazards needed to be quantified in order to choose the ‘healthiest’ route. Process Route Healthiness Index (PRHI) has been developed to foresee the potential health hazards from chemical processes. PRHIP ranks process routes in terms of their occupational healthiness. The higher the index, the higher is the hazard. PRHI is influenced by the health impact due to chemical releases and the concentration of airborne chemicals inhaled by workers. In this article, PRHI has been applied on six alternative routes for Methyl Methacrylate (MMA). The results of the ranking was compared to the Inherent Safety Index, Environmental Hazard Index and production costs for the six alternative chemical process routes.

Key words: Occupational health hazard, assessment method, ISHE, ranking index
Computer-Based Accounting Systems: The Case of Manufacturing-Based Small and Medium Enterprises in the Northern Region of Peninsular Malaysia
Authors: Ismail Noor Azizi , Abdullah Shamsul Nahar , Tayib Mahamad
Published: January 2013

Kajian ini menguji status penggunaan sistem perakaunan berkomputer (CBAS) di kalangan industri kecil dan sederhana di Wilayah Utara Semenanjung Malaysia. Dapatan kajian menunjukkan bahawa tahap penggunaan CBAS adalah melebihi sembilan puluh peratus. Walau bagaimanapun, CBAS yang digunapakai pada umumnya adalah di peringkat asas yang mana majoriti syarikat hanya menggunakan CBAS untuk tempoh enam tahun atau kurang. Dapatan kajian menunjukkan bahawa tempoh penggunaan CBAS berhubung langsung secara positif dengan kualiti keseluruhan CBAS. Hasil kajian juga mendapati hubungan di antara kematangan kepenggunaan CBAS dan usia sesebuah syarikat adalah berkait rapat pada arah positif. Walau bagaimanapun, dapatan kajian tidak menemui kesan positif usia dan saiz perniagaan dengan bentuk pemilikan ke atas pengunaan CBAS.

Kata kunci: Penggunaan sistem perakaunan berkomputer, teknologi maklumat, industri kecil dan sederhana

This study investigates the status of computer-based accounting systems (CBAS) adoption among small and medium manufacturing firms (SMEs) in the northern region of Peninsular Malaysia. Results show that over ninety percent of the firms have adopted CBAS. The adoption of CBAS, however, is still at the beginning stage as majority of the firms only adopted CBAS in the last six years or less and the depth of the CBAS system adopted is behind that of industrialized countries. The results showed that years of adoption are positively correlated with the overall quality of the CBAS adopted. Further investigations on the relationships between CBAS use items and factors that were expected to affect CBAS use indicate that the maturity stage of CBAS adoption was significantly positively correlated with age of business. However, the results did not find evidence supporting previous research that argued age and size of the firms as well as the type of ownership influence the adoption of CBAS.

Key words: Adoption of computerized accounting systems, information technology, small and medium enterprises
Development of Step Hole Recognition System for Computer Aided Process Planning
Authors: Tan C. F. , Ismail N. , Wong S. V. , Sulaiman S. , Osman M. R.
Published: January 2013

Sistem CAD masa kini mewakili komponen dengan vertex, garis, permukaan dan/atau isipadu. Perwakilan ini tidak sesuai untuk kebanyakan applikasi pembuatan seperti Perancangan Proses Terbantu Komputer (CAPP). Pada tahap pembuatan, kebanyakan keputusan adalah berdasarkan pada entiti tertinggi di mana ia biasa dipanggil sebagai sifat pembuatan. Kertas kerja ini membincangkan pembangunan Sistem Pengecaman Lubang STEP yang dinamakan S_HoRS untuk Perancangan Proses Terbantu Komputer. S_HoRS akan menukarkan data geometri terutamanya lubang dari fail STEP kepada model berdasarkan sifat, sesuai untuk aktiviti perancangan proses terutamanya bagi komponen alatan dan acuan. Algoritma yang berdasarkan aturan digunakan dalam proses pengecaman. Perlaksanaan terkini bagi sistem tersebut terhad untuk sifat lubang sahaja.

Kata kunci: Sifat lubang, perancangan proses berbantu komputer, pengecaman sifat, sifat lubang, fail STEP, algoritma berasaskan aturan

Current CAD system represents part by set of vertices, lines face and/or volume. This type of presentation is not suitable for most manufacturing application such as Computer Aided Process Planning (CAPP). At manufacturing level, decisions are mainly based on higher entities, which are commonly called manufacturing features. This paper describes the development of STEP Hole Recognition System called S_HoRS for CAPP. S_HoRS will convert geometrical data specifically holes from the STandard for the Exchange of Product model data (STEP) file into feature based model suitable for process planning activities, especially for tool and die components. Ruleâ€“based algorithm is used for the recognising process. The output from S_HoRS is the holeâ€™s feature data such as radius, height and the coordinates system. Current implementation of the S_HoRS is limited to simple hole features.

Key words: Hole features, computer aided process planning, feature recognition, STEP file, rule-based algorithm
Microstructural Characterisation of Asâ€“Cast Binary Near Gamma Titanium Aluminides
Authors: Hamzah Esah , Kanniah Maiiyeaalagan , Harun Mohd.
Published: January 2013

Sebatian antara logam berasaskan sebatian Tiâ€“Al mempamerkan sifat yang menyakinkan untuk aplikasi suhu tinggi. Walau bagaimanapun, hanya aloi dua fasa hampir gamma mampu sedikit sebanyak memenuhi aplikasi suhu tinggi yang penting. Oleh itu, pada dekad yang lepas, banyak kajian telah ditumpukan kepada mengoptimumkan aplikasi aloi baru ini. Oleh kerana sifat suhu tinggi terutama berkaitan dengan rayapan yang sangat bergantung kepada mikrostruktur, kefahaman menyeluruh mengenai mikrostruktur ini diperlukan. Dalam kertas kerja ini, pengetahuan semasa mengenai mikrostruktur aloi tuangan binari hampir gamma titanium aluminaid akan dibincangkan.

Kata kunci: Hampir gamma titanium aluminaid, mikrostruktur, saiz bijian, pecahan isipadu, morphologi sempadan bijian

Intermetallics based on Tiâ€“Al compounds exhibits promising properties for high temperature applications. However, only two phase near gamma alloys are able to some extent fulfill the crucial high temperature applications. Therefore during the past decade, a number of research efforts were directed to optimise the application of this recently emerging class of alloy. Since the high temperature property which mainly concerns creep is strongly microstructure dependent, a comprehensive understanding on the microstructure is needed. In this paper, the current knowledge on the microstructures of as cast binary near gamma titanium aluminides will be addressed.

Key words: Near gamma titanium aluminides, microstructure, lamellae, nearly lamellae, duplex
Verification Of Weibullâ€™s Theory Of Brittle Fracture To Merantiâ€™s Timber Loaded In Tension Parallel To The Grain
Authors: Abu Bakar Suhaimi , Saleh Abd Latif
Published: January 2013

Kayu sudah dikenali ramai sebagai bahan yang rapuh di bawah pembebanan tegangan dan mempunyai sifat tidak homogen. Sungguhpun teori rapuh musnah Weibull sudah disahkan untuk kayu lampung, pengesahan teori ini terhadap spesis kayu keras terutamanya daripada kalangan kayu spesis tempatan adalah sangat terhad. Kertas kerja ini mengemukakan pengesahan teori Weibull terhadap kayu tempatan untuk spesis Meranti yang dibebani secara tegangan selari dengan ira. Penganggaran teori dibandingkan dengan keputusan ujian. Taburan kekuatan tegangan pada beberapa kebarangkalian ditemui hampir sama dengan penganggaran teori. Dua nilai parameter Weibull dicadangkan dalam formulasi penganggaran kekuatan tegangan untuk kayu tempatan. Juga ditemui, kekuatan tegangan bagi kayu tempatan dipengaruhi oleh isipadu kayu tersebut.

Kata kunci: Teori Weibull, musnah rapuh, kebarangkalian gagal, ujian tegangan kayu, spesis Meranti

Timber is a wellâ€“known brittle material under tensile load and is also an inhomogeneous material. Although Weibullâ€™s theory of brittle fracture is well established for softwood timber, the verification of this theory to hardwood species, particularly to the timber of local species is very limited. This paper presents the verification of Weibullâ€™s theory to local timber of Meranti species loaded in tension parallel to the grain. The theoretical prediction is compared to the test results. It is found that the variation of tensile strength at several probabilities is in close agreement with theoretical prediction. Two values of Weibullâ€™s parameters were proposed in the formulation to predict the tensile strength for local timber. It is also found that the tensile strength of local timber is affected by its volume.

Key words: Weibullâ€™s theory, brittle fracture, probability of failure, timber tension tests, Meranti species
Kajian Perbezaan Dalam Klasifikasi Kawasan Berbukit Dari Hasilan Kecerunan Berbagai Perisian Sistem Maklumat Geografi (GIS)
Authors: Mohd Shariff Noresah , Rainis Ruslan
Published: January 2013

Artikel ini melaporkan hasilan satu penyelidikan mengenai klasifikasi kawasan berbukit menggunakan maklumat kecerunan dari sistem maklumat geografi (GIS). Sebanyak empat perisian GIS telah diuji iaitu IDRISI32 for Windows, Erdas Imagine, ArcView dan GridAnalyser. Hasil kajian mendapati bahawa kesemua perisian tersebut menghasilkan maklumat kecerunan berbeza dan seterusnya mempengaruh klasifikasi kawasan berbukit. Perbezaan ini berbagai, ada yang berbeza sedikit sahaja (ArcView dan GridAnalyser) iaitu 0.04%, manakala ada juga yang besar sehingga 5.0% (IDRISI32 dan Erdas Imagine). Menyedari hakikat bahawa penggunaan perisian GIS yang berbeza boleh menghasilkan hasilan yang berbeza, maka satu kajian yang komprehensif harus dijalankan oleh agensi-agensi yang berwajib agar dapat menetapkan satu nilai tolerans yang dibenarkan yang boleh dijadikan panduan oleh semua pihak.

Kata kunci: Kecerunan, sistem maklumat geografi, kawasan berbukit

This article reports the result of a research on the classification of hilly areas using slope information from geographic information system (GIS). Four GIS softwares were tested i.e. IDRISI32 for Windows, Erdas Imagine, ArcView, and GridAnalyser. The results of the study found that all the softwares produced different slope information, thus influencing the classification of hilly areas. The differences vary, ranging from as small as 0.04% (ArcView and GridAnalyser) to a large difference of 5.0% (IDRISI32 and ERDAS Imagine). Given the fact that different GIS software might produce different results, a comprehensive study should be carried out by the relevant agencies to set an acceptable tolerance value to be used as a general guide to all users.

Key words: Slope, geographic information system, hilly areas
Effects of pH on Ethanol Photocatalytic Oxidation Using TiO2 and Zeolite 13X as Catalyst
Authors: Jamaludin Norzita
Published: January 2013

Proses pengoksidaan fotomangkin adalah suatu teknik yang amat berguna dalam rawatan bahan pencemar organik. Dalam kajian ini, keberkesanan dua jenis mangkin iaitu, TiO2 dan zeolite 13X dalam mengoptimumkan proses pengoksidaan fotomangkin bagi etanol dalam fasa akueus diuji dari segi keberkesanan penjerapan etanol dan kuantiti asetaldehid yang dihasilkan sebagai produk perantaraan bagi tindakbalas fotomangkin ini. Selain itu, kesan pH ke atas proses pengoksidaan fotomangkin ini juga ditentukan. Eksperimen telah dijalankan di bawah sinar UV dengan kehadiran oksigen terlarut. Persampelan dibuat setiap 40 minit untuk selama 200 minit di bawah pendedahan sinar UV pada berbagai pH berbeza (pH 3, pH 5, pH 7 dan pH 9). Sampel-sampel tersebut dianalisis menggunakan teknik HPLC. Hasil daripada uji kaji menunjukkan bahawa TiO2 mempunyai keberkesanan yang lebih tinggi berbanding zeolite 13X dari segi penyerapan etanol (iaitu menyerap lebih banyak etanol) dan dari segi penghasilan asetaldehid (iaitu menghasilkan kuantiti asetaldehid yang lebih rendah). Hasil kajian juga menunjukkan bahawa proses pengoksidaan fotomangkin bagi etanol mencapai tahap optimum dalam keadaan berasid. Begitu juga, hasil kajian mendapati jangkamasa pendedahan sistem fotomangkin kepada sinar UV memainkan peranan yang penting dan memberi kesan yang hebat terhadap proses pengoksidaan fotomangkin bagi etanol.

Kata kunci: Pengoksidaan fotomangkin, TiO2, zeolite 13X, penyerapan etanol, penghasilan asetaldehid, nilai pH

Photocatalytic oxidation is a very beneficial technique used in the treatment of various organic pollutants. In this research, two of the most prominent catalysts, TiO2 and zeolite 13X were tested for their ability in optimising the photocatalytic oxidation of ethanol in aqueous solution in terms of ethanol adsorption and production of acetaldehyde as an intermediate for the reaction. Besides that, the effects of pH on the photocatalytic oxidation of ethanol in an aqueous solution by using TiO2 and zeolite 13X as catalysts were also determined. The experiments were conducted under UV irradiation with the presence of dissolved oxygen. Samples were taken every 40 minutes for 200 minutes of irradiation at different pH values (pH 3, pH 5, pH 7 and pH 9) and then analysed by HPLC. The findings of the experiments indicated that TiO2 was a better catalyst compared to zeolite 13X in terms of ethanol adsorption (i.e. adsorbs more ethanol) and the production of acetaldehyde as an intermediate product (i.e. produces less acetaldehyde). The results also indicated that the optimum level for photocatalytic oxidation of ethanol was in acidic condition. It was also found that the duration of irradiation plays a big role and shows tremendous effect to the photocatalytic oxidation of ethanol.

Keywords: Photocatalytic oxidation, TiO2, zeolite 13X, ethanol adsorption, acetaldehyde production, pH values
Boundary Layer Flow Due to a Moving Flat Plate in Micropolar Fluid
Authors: Salleh Mohd. Zuki , Mohd Rohni Azizah , Amin Norsarahaida
Published: January 2013

Pemodelan matematik bagi aliran lapisan sempadan terhadap plat rata bergerak telah dibincangkan. Satu plat bergerak berterusan dalam arah positif paksiâ€“x dengan halaju tetap. Persamaan lapisan sempadan yang dihasilkan telah diselesaikan secara berangka dengan menggunakan skema beza terhingga tersirat. Keputusan berangka telah diberikan, ini termasuk profil halaju, profile komponen legaran dan perubahan tegasan ricih permukaan. Kajian ini menunjukkan bahawa keputusan bagi masalah dalam bendalir mikropolar berbanding dengan bendalir likat adalah sangat memuaskan apabila parameter bahan K = 0 (bendalir Newtonan). Seterusoya tegasan ricih permukaan meningkat dengan peningkatan nilai K. Untuk nilai K yang ditetapkan, didapati tegasan ricih permukaan menyusut dan kompenan legaran meningkat dengan peningkatan nilai n, dalam selang O
Home and Office Environments Using Bluetooth Technology
Authors: Zakiah Sahbudin Ratna Kalos , Azhar Nurulaza , Aris Ishak , Kean Jeet Goh
Published: January 2013

Teknologi Bluetooth yang mana telah mendapat sokongan daripada syarikatâ€“syarikat terkemuka merupakan satu penyelesaian untuk menghapuskan penggunaan wayarâ€“wayar, kabelâ€“kabel dan penyambungâ€“penyambung yang berkaitan di antara telefon bergerak, modem, komputer, pencetak, PDA dan sebagainya. Kertas kerja ini membentangkan pembangunan rangkaian kediaman dan pejabat secara wayarles dengan menggunakan Ericsson Bluetooth Module (ROK101 008). Kod punca telah ditulis dalam bahasa pengaturcaraan Visual Basic 6.0 (VB) dan juga menggunakan komponen ActiveX. Modul Bluetooth tersebut dapat menghantar data dan mengawal perantiâ€“peranti yang berada dalam jarak 10 meter. Satu komputer disambungkan kepada satu modul Bluetooth dan dijadikan induk. Satu lagi modul Bluetooth disambungkan kepada mikropengawal PIC16F84A dan perantiâ€“peranti dan dijadikan hamba. Perantiâ€“peranti tersebut boleh dikawal secara wayarles melalui modul Bluetooth tersebut.

Kata kunci: Teknologi Bluetooth, komunikasi wayarles, induk, hamba, mikropengawal

Bluetooth technology which has gained the support from leading manufacturers is a promising solution to eliminate the need for wires, cables and the corresponding connectors between mobile phones, modems, computers, printers, PDAs and so on. This paper describes the development of home and office environment using Ericsson Bluetooth Modules (ROK101 008). The source code is written in Visual Basic 6.0 (VB) and used ActiveX component. The Bluetooth modules are able to transfer data and control the devices in the range of 10 meters. A personal computer (PC) is connected to a Bluetooth module and acts as a master. Another Bluetooth module is connected to a microcontroller PIC16F84A and the devices and acts as the slave. The devices can be controlled wirelessly via the Bluetooth modules.

Key words: Bluetooth technology, wireless communication, master, slave, microcontroller
System Identification of Hammerstein Model a Quarter Car Passive Suspension Systems Using Multilayer Perceptron Neural Networks (MPNN)
Authors: Hanafi Dirman , Rahmat Mohd.Fuaâ€™ad
Published: January 2013

Sejak kebelakangan ini, ramai penyelidik telah memberi perhatian kepada aplikasi rangkaian neural untuk pengenalpastian sistem. Dalam penulisan ini, model Hammerstein untuk suspensi pasif kereta suku telah dikenal pasti menggunakan rangkaian perceptron neural anggapan berbilang lapis. Data masukan dan keluaran telah diperolehi dengan memandu sebuah kereta pada satu paras jalan yang khas. Struktur daripada rangkaian adalah berdasarkan kepada model daripada sistem. Rangkaian algoritma pembelajaran adalah berdasarkan kaedah pemarkahan Fisher. Maklumat Fisher ini diberikan sebagai pemberat matrix kovarian masukan dan keluaran lapisan rangkaian yang tersembunyi. Unitwise daripada kaedah pemarkahan Fisher berkurangan kepada algoritma di mana setiap unit menganggarkan sendiri pemberat dengan menggunakan kaedah pemberat kuasa dua terkecil. Hasilnya telah menunjukkan bahawa nilai ralat minimum punca knasa dua proses pembelajaran diperoleh dengan satu lelaran yang singkat.

Kata kunci: Pengenalpastian sistem, model Hammerstein, rangkaian perceptron neural berbilang lapis, pemberat kuasa dua terkecil, maklumat Fisher, pemarkahan Fisher

Recently, some researchers have focused on the applications of neural networks for system identification. In this paper, a Hammerstein model of a quarter car passive suspension system is identified using multilayer perceptron neural networks. Input and output data are acquired by driving a car on a special road event. The networks structure is based on system model. The network learning algorithm is based on Fisherâ€™s scoring method. Fisher information is given as a weighted covariance matrix of inputs and outputs of the network hidden layer. Unitwise, Fisherâ€™s scoring method reduces to the algorithm in which each unit estimates its own weights by a weighted least square method. The results show that the minimum mean square error (MSE) value of the training process was found with a short record.

Key words: System identification, Hammerstein model, multilayer perceptron, weighted least square, Fisher information, Fisherâ€™s scoring
Analysis of Carbon Dioxide Reforming of Methane via Thermodynamic Equilibrium Approach
Authors: Tung Chun Yaw , Saidina Amin Nor Aishah
Published: January 2013

Pembentukan air melalui reverse watergas shift serta tindakbalasâ€“tindakbalas sampingan lain dalam proses pembentukan semula metana menggunakan karbon dioksida (CORM) menjadi salah satu masalah utama yang menghadkan penghasilan maksima hidrogen and singas (campuran H2â€“CO). Dengan ini, kajian ke atas keseimbangan termodinamik CORM seharusnya mengambil kira kesan pembentukan air dalam rangkaian tindakbalas CORM. Disebabkan oleh rangkaian tindakbalas CORM yang kompleks, kaedah Lagrangeâ€™s undetermined multiplier digunakan dalam kajian ini dan keberkesanannya telah dibuktikan. Prestasi equilibria CORM dipertingkatkan daripada 600K kepada lOOOK tetapi kesan suhu menjadi tidak bermakna pada suhu melebihi 1OOOK. Nisbah CO/H2 menghampiri satu boleh dicapai dengan nisbah suapan CO2/CH4 yang rendah tetapi nisbah suapan CO2/CH4 yang sama diperlukan untuk memperoleh penghasilan H2 dan CO yang tinggi pada suhu lOOOK ke atas. Keputusan ini disokong oleh keputusan eksperimen seperti yang dilaporkan dalam literatur.

Kata kunci: Karbon dioksida, metana, singas, pembentukan air, Lagrangeâ€™s undetermined multiplier

Water formation through reverse water gas shift and several other side reactions in carbon dioxide reforming of methane (CORM) have became one of the major process hurdles that limits maximum hydrogen and syngas (H2â€“CO mixture) yields. Therefore, it is vital that the study on CORM thermodynamic equilibrium takes into consideration the formation of water in the CORM reaction network. Due to the complexity of the reaction network, Lagrangeâ€™s undetermined multiplier was employed in the present work and its applicability had been proven throughout this study. The equilibrium compositions improved drastically from 600â€“1OOOK, but the temperature effect becomes insignificant above 1OOOK. Furthermore, CO/H2 ratio close to unity can be achieved at lower CO2/CH4 feed ratios but equal CO2/CH4 feed ratios is required to obtain higher H2 and CO yields at temperature lOOOK and above. These findings are in strong agreement with laboratory experimental results reported in literature.

Key words: Carbon dioxide, methane, syngas, water formation, Lagrangeâ€™s undetermined multiplier
The Effect of Curing Temperature on the Performance of Thin Film Composite Membrane
Authors: Idris Ani , Kormin Faridah , Mohd.Suput Mohd.Zakiamani
Published: January 2013

Kesan suhu rawatan pada prestasi membran komposit dikaji menggunakan dua jenis membran penyokong polimer iaitu selulosa asetat dan polisulfona. Larutan fasa akuas disediakan dengan melarutkan mâ€“fenildiamina, tetrabutilammonium bromida, natrium hidroksida dan hidroquinon berdasarkan komposisi di dalam air suling. Larutan fasa organik disediakan dengan melarutkan trimesil klorida dalam nâ€“heksana. Membran komposit disediakan dengan menggunakan kaedah pempolimeran antara muka. Pempolimeran berlaku dalam fasa organik melalui tindak balas antara muka antara mâ€“fenildiamina, hidrokuinon dan trimesil klorida untuk menghasilkan rangkaian poliesteramida. Suhu rawatan di dalam julat 40Â°C hingga 100Â°C digunakan dalam oven semasa proses tindakbalas antara muka. Penilaian prestasi membran komposit terhadap kadar penyingkiran garam dan fluks dilakukan menggunakan sel penelapan ringkas. Hasil uji kaji menunjukkan membran komposit selulosa asetat dengan suhu rawatan 60Â°C menunjukkan kadar penyingkiran terbaik sebanyak 76% manakala membran komposit polisulfona dengan suhu rawatan 80Â°C memberikan kadar penyingkiran yang terbaik sebanyak 80%.

Kata kunci: Membran lapisan komposit, fasa organik, fasa akuas, suhu rawatan

The effect of curing temperature on the performance of thin film composite membranes was studied using two different kinds of polymeric membrane supports, i.e. cellulose acetate and polysulfone. Aqueous phase solution was prepared by dissolving mâ€“phenyldiamine, tetrabutylammonium bromide, sodium hydroxide and hydroquinone based on the composition in distilled water. Organic phase was prepared by dissolving trimesoyl chloride in nâ€“hexane. Polymerization occurred in the organic phase by interfacial reaction of mâ€“phenyldiamine with the presence of trimesoyl chloride to form polyesteramides. Curing temperatures ranging from 40Â° to 100Â°C were used in the airâ€“circulated oven during the interfacial reaction process. The performances of the thin film composite membranes in terms of salt rejection and permeation rate were evaluated using the permeation cell. The results showed that cellulose acetate thin film composite membrane cured at 60Â°C gives the best rejection rate of 76% whilst polysulfone thin film composite membrane cured at 80Â°C gives the highest rejection rate of 80%.

Key words: Thin film composite membrane, aqueous phase, organic phase, curing temperature
Performance Of Hybrid Learning Control With Input Shaping For Input Tracking And Vibration Suppression Of A Flexible Manipulator
Authors: Md. Zain M. Z. , Tokhi M. O. , Mohamed Z.
Published: January 2013

Objektif kertas kerja ini ialah untuk mengkaji keberkesanan gabungan pengawal pembelajaran berulang cerdik dan teknik pembentuk masukan bagi penjejakan masukan dan pengurangan getaran pada hujung suatu pengolah fleksibel. Model dinamik sistem tersebut diterbitkan menggunakan kaedah unsur terhingga. Pada permulaan, pengawal kadaran–kebezaan (PD) menggunakan sudut dan halaju hub direka bentuk untuk kawalan pergerakan badan tegar sistem. Kemudian, pengawal pembelajaran berulang dengan algoritma genetik dan pengawal suap hadapan berasaskan teknik pembentuk masukan ditambahkan untuk kawalan getaran sistem. Keputusan simulasi dalam domain masa dan frekuensi diberikan. Keberkesanan pengawal yang direka bentuk ini dikaji berasaskan penjejakan masukan dan kadar pengurangan getaran sistem. Keberkesanan pengawal ini untuk sistem pengolah fleksibel berbagai beban juga dikaji.

Kata kunci: Pengolah fleksibel, algoritma genetik, kawalan cerdik, kawalan pembelajaran berulang, pembentukan masukan

The objective of the work reported in this paper is to investigate the performance of an intelligent hybrid iterative learning control scheme with input shaping for input tracking and end–point vibration suppression of a flexible manipulator. The dynamic model of the system is derived using finite element method. Initially, a collocated proportional–derivative (PD) controller utilizing hub–angle and hub–velocity feedback is developed for control of rigid–body motion of the system. This is then extended to incorporate iterative learning control with genetic algorithm (GA) to optimize the learning parameters and a feedforward controller based on input shaping techniques for control of vibration (flexible motion) of the system. Simulation results of the response of the manipulator with the controllers are presented in time and frequency domains. The performance of hybrid learning control with input shaping scheme is assessed in terms of input tracking and level of vibration reduction. The effectiveness of the control schemes in handling various payloads is also studied.

Key words: Flexible manipulator, genetic algorithms, intelligent control, iterative learning control, input shaping
Evaluation And Development Of Cut–Slope Assessment Systems For Peninsular Malaysia In Predicting Landslides In Granitic Formation
Authors: Jamaludin Suhaimi , Huat Bujang B. K. , Omar Husaini
Published: January 2013

Penilaian cerun dijalankan bagi meramal kebarangkalian berlakunya kejadian tanah runtuh dan juga tahap kemusnahannya di sesuatu kawasan yang dinilai. Dalam kertas kerja ini, empat sistem penilaian cerun (SAS) sedia ada bagi meramal kejadian tanah runtuh pada skala mikro yang telah dibangunkan oleh Jabatan Kerja Raya (JKR) Malaysia iaitu Slope Maintenance System (SMS), Slope Priority Ranking System (SPRS), Slope Information Management System (SIMS) dan Slope Management and Risk Tracking System (SMART) telah dikaji. Daripada hasil kajian, adalah jelas tiada sebarang satu SAS sedia ada yang sesuai bagi meramal kejadian tanah runtuh di kawasan yang didasari batuan granit. Ini adalah kerana beberapa sebab yang jelas iaitu antaranya skor bahaya yang digunakan diadaptasi dari negara luar, pengkalan data yang terhad, dan juga pengkalan data yang digunakan adalah daripada formasi batuan yang berbeza. Dalam kajian ini, dua SAS baru telah dibangunkan iaitu Model A yang menggunakan persamaan sepuluh parameter yang dibentuk dari analisa discriminant, dan Model B yang menggunakan persamaan sembilan parameter yang dibentuk dari analisa linear regression. Kedua–dua model baru ini jelas menunjukkan ia lebih sesuai bagi meramal kejadian tanah runtuh di kawasan didasari batuan granit.

Kata kunci: Analisa discriminant, formasi granit, tanah runtuh, sistem penilaian cerun

A slope assessment is carried out to predict the probability of occurrence and the degree of severity of landslides in a given area. This paper evaluates four existing slope assessment systems (SAS) for predicting landslides at micro level of assessment developed by the Public Works Department of Malaysia, namely the Slope Maintenance System (SMS), Slope Priority Ranking System (SPRS), Slope Information Management System (SIMS) and the Slope Management and Risk Tracking System (SMART). From the results of this study, it appears that none of the existing SAS is satisfactory for predicting landslide in granitic formation, due to various reasons such as the use of hazard score developed from another country, insufficient database, and the use of data base derived from different rock formations. Two new SAS were developed, i.e. Model A using ten–variables equation that is based on the stepwise discriminant analysis, and Model B using ninevariables equation that is based on the stepwise linear regression analysis. These two new models appear to be suitable for predicting landslides in granitic formations than the existing four SAS.

Key words: Discriminant analysis, granitic formation, landslide, slope assessment system
Penyaduran Nikel Tanpa Elektrik Ke Atas Plastik ABS Bergred Tidak Boleh Disadur
Authors: Mohamad Ibrahim M. N. , Izat M. E. , Lau L. L. , Abdullah T. K.
Published: January 2013

Kajian ini adalah menyadur plastik Akrilonitril–Butadiena–Stirena (ABS) yang bergred tidak boleh disadur dengan logam nikel menggunakan teknik salutan lapisan bawah. Kaedah salutan lapisan bawah yang diperkenalkan dalam kajian ini didapati mampu memberikan kualiti penyaduran yang memuaskan. Beberapa jenis bahan serta campuran bahan diuji keberkesanan masing–masing agar dapat bertindak sebagai lapisan laker atau sampang. Hasil pemerhatian kualitatif mendapati bahawa sampang yang diperbuat daripada n–butil asetat memberikan kualiti penyaduran yang terbaik berbanding dengan empat lagi bahan atau campuran bahan yang lain iaitu campuran polivinil klorida (PVC) dan bahan pemplastik diisononil ftalat (DINP–S), campuran PVC dan n–butil asetat, etil asetat dan campuran n–butil asetat dan 2–propanol. Selain kelihatan lebih menarik, penyaduran logam nikel ke atas substrat melalui kaedah ini yang menggunakan n–butil asetat sebagai sampang memberikan kekuatan saduran yang setanding dengan kaedah konvensional.

This study is to coat the non–platable grade Acrilonitrile–Butadiene–Styrene (ABS) plastic with nickel by using underlayer coating technique. The underlayer coating technique introduced in this study has been proven to give satisfactory quality of plating. Several types of substances and their mixture were tested for their effectiveness as a lacquer. Results from qualitative observation showed that lacquer which was made from n–butyl acetate gives the best quality of coating compared to the other four substances or mixture which are the mixture of polyvinyl chloride (PVC) and diisononyl phthalate (DINP–S), mixture of PVC and n–butyl acetate, ethyl acetate and a mixture of n–butyl acetate and 2–propanol. Besides being more attractive, the nickel plating on the substrate using this method which used n–butyl acetate as lacquer gave comparable coating strength with the conventional method.
Analysis Of Selenium Species Using Cathodic Stripping Voltammetry
Authors: Mohamed Rugayah , Leong Wei Lee
Published: January 2013

M respectively when an accumulation potential of 100 mV was applied for 90 seconds. Simultaneous determination of selenite and dimethyl diselenide was also carried out. The effect of selenite on the determination of dimethyl diselenide and vice versa was studied. The influence of metal ions such as lead, copper, cadmium and zinc on the reduction signals for selenite and dimethyl diselenide was also investigated.

Key words: Cathodic stripping voltammetry, Se(IV), dimethyldiselenide
Effect Of Heat Treatment On The Performance And Structural Details Of Polyethersulfone Ultrafiltration Membranes
Authors: Idris Ani , Mat Zain Norashikin
Published: January 2013

) of the membranes were determined from solute transport data. It is observed that solute separation using PEG 35000 Daltons increased while flux decreased as the heating temperature increases. The MWCO and pore size of the membranes decreased with increased heating temperatures. Surface and cross section of PES UF membranes were characterized before and after heating using Scanning Electron Microscope (SEM). Atomic Force Microscopy (AFM) analysis revealed significant changes were observed in the surface of PES UF membrane with increased heating temperatures. The performance of the membrane was not only affected by heat treatment but also the heating temperatures.

Key words: Ultrafiltration, polyethersulfone, heating, temperature, polyethylene glycol
The Effects Of Lignin Purification On The Performance Of Iron Complex Drilling Mud Thinner
Authors: Mohamad Ibrahim M. N. , Azian H. , Mohd Yusop M. R.
Published: January 2013

, which suggests that purification process is not required to increase the performance of chelated ferrous ion drilling mud thinner.

Key words: Oil palm empty fruit bunches, black liquor, purification, soda lignin, drilling mud thinner, rheological properties