bluuebunny/crossref_metadata_2025 huggingface dataset:
The Potential Usage Of Steelmaking By-Products: Electric Arc Furnace Dust
Authors: Idris Jamaliah , Kim Siong Tee
Published: January 2013

During the steel manufacturing processes, by-products such as electric arc furnace (EAF) dust, rich in metallic oxides, are generated. In Malaysia. EAF dust is presently dumped or landfilled. However, as we forge ahead to achieve Malaysia's Vision 2020 to be a fully industrialised nation, we should not lose sight of the various regulations to protect the environment. EAF dust, presently listed as N201 and classified as scheduled waste under the Environmental Quality (Scheduled Waste) Regulations, 1989, contains heavy metals such as zinc, lead, cadmium and chromium. Heavy metals are harmful substances which are prohibited from being dumped directly. They are also valuable mineral resources. The high percentage of zinc in EAF dust suggests the potentiality to extract this valuable metal. In view of the difficulty in obtaining licence and land for dumping or landfill, and the tremendous increase in cost for present method of disposing EAF dust, a series of tests had been done to identify the potential usage of this by-product. This paper aims to direct iron and steel industry in Malaysia on the right path to the conversion of non-usable EAF dust into the recovery or valuable metals such as zinc, lead, iron, chromium, cadmium or nickel.
Fenomena Cincin Pusaran Oleh Gelembung Peronggaan Berhampiran Sempadan Pepejal
Authors: Hanapei Md. Hisam , Bidin Noriah
Published: January 2013

Akibat dari bcncana hakisan yang dijanakan oleh gelembung peronggaan,maka ahli-ahli fizik telah mengambil langkah-langkah untuk mencari punca hakisan tersebut. Salah atau punca yang telah dapat dikesan adalah kehadiran fenomena cincin pusaran dalam proses dinamik gelembung peronggaan dan sering dihubung kaitkan dengan kesan kerosakan bentuk annular. Kertas kerja ini dijalankan bertujuan untuk membuat kajian yang lebih mendalam dan terperinci mengenai kewujudan-kewujudan cincin pusaran. Teknik pemfokusan laser dan teknik fotograti kelajuan tinggi telah digunakan untuk merakamkan proses dinamik cincin pusaran. Didapati fenomena ini telah mula dikesan dari peringkat penguncupan pertama dalam cecair bebas dan juga berhampiran permukaan sempadan. Kejadian ini juga didapati mudah dikesan pada sempadan permukaan bebas yang berhampiran.

Kata Kunci:peronggaan,cincin pusaran,annular,laser,penguncupan
Nonlinear Response Of Steel Girder Bridges Under Various Directions And Intensities Of Earthquake Motions
Authors: Adnan Azlan , Mohd. Ghazali Mohd.Zulkifli , Mohammadi Jamshid
Published: January 2013

This paper presents an investigation into the behavior of reinforced concrete slabs, steel girders, and concrete columns of a two span steel girder bridge under the influence of different combination of earthquake directions and intensities. The beam-column elements were used to represent the composite bridge deck (concrete slab and steel girder) and also the concrete columns. This element type has the nonlinear material capability. The free vibration analysis was performed to detect the first four mode shapes of the bridge models. Time history analysis was implemented on the bridge when subject to San Fernando Earthquake, 1971. Various failure patterns were detected by examming the maximum displacement patterns, and the maximum forces (or stresses) of the bridge components. Significant amplification of the bridge response occured in all directions, longitudinally, transversely, and vertically as a result of the combination effect of earthquake in the other directions.
Initial Development Of OC-Based Flight Dynamics Engineering Simulator
Authors: Mansor Shuhaimi , Yaacob Amir Fadhil
Published: January 2013

Flight simulation had played a very important role in aerospace and aviation industries as an engineering tool and training equipment. Computers provided the capability of stimulating an aircraft in flight without actually flying the aircraft, thus providing safety to pilots and also cost reduction in pilot training and aircraft design. Aerodynamic characteristics were modelled mathematically to display the air craft orientation and the aircraft motion during manoeuvres. Implementation of aerodynamic database system enables a flight simulator to stmulate many types of aircraft manoeuvres.
A Field Evaluation Of Particulate Emission Concentrations In Palm Oil Mill Boilers
Authors: Rashid M. , Ramli M. , Rozainee M.
Published: January 2013

A field evaluation on particulate emission concentrations from two different types of palm oil mill boilers (i.e water-tube, WT, and fire-tube, FT type boilers) was performed using a standard stack sampling procedures. A total of 12 WT and 12 FT boilers were studied. Six of the 12 WT boilers were equipped with multi-cyclones as a means of controlling particulate emissions from the boilers, whilst all 12 FT boilers were without any form of air particulate control equipment. Results showed that the mean particulate emission concentrations from water-tube type boilers with and without particulate control equipment installed was 1.11 ± 0.58 g/Nm3 and 1.93 ± 1.40 g/Nm3 respectively. There was no significant difference in the particulate emissions between WT boilers with or without particulate control installed. It was found that only one out of the six WT boilers with particulate control was able to meet the emission standards limit of 0.40 g/Nm3 while others were still violating the standard. Meanwhile, the mean particulate emission from all 12 FT type boilers (all were without control) was 0.5 1 ± 0.27 g/Nm3, which was found to be significantly lower (p 0.01) compared to the WT boiler emissions of without particulate control.Apparently, the characteristic of particulate size distributions generated by the two types of boilers could be an important factor affecting the findings and it is discussed further in this paper.

Keywords :air pollution, particulate, palm oil mill, boilers.
Soil Improvement Techniques
Authors: Hj. Yusuf Mohd. Zain
Published: January 2013

Masalah tapak bina semasa dan setelah siap pembinaan sesuatu projek adalah banyak. Kehadiran air tanah, darjah pengkemasan dan perlekatan antara zarah serta kepenuhan liang mempunyai pengaruh yang besar dalam sifat dan kelakunan tanah. Terdapat beberapa cara memperelokkan tanah dan usaha telah dibuat, menerusi kertas kerja ini, untuk menerangkan penggunaan kawalan air tanah, pengkemasan cara mekanikal dan penggunaan bahan kimia dalam pengelokan tanah. Namun demikian pemilihan sesuatu cara tertentu bergantung kepada jenis tanah yang terdapat di kawasan pembinaan itu.

The foundation problems faced during and after finishing the construction of a project are numerous. The presence of groundwater, the degree of densification and particulate cementation and void filling have immense contribution in the soil characteristics and performance. Several techniques of soil improvement are available and attempts have been made, in this paper, to explain the utilisation of groundwater control, mechanical means of densification and the usage of chemicals in the treatment of soils. The choice of a particular method is
dependent on the type of soil available at site.
A Numerical Study of Air Flow in a Coaxial Pipe
Authors: Surjosatyo Adi , Nasir Ani Farid
Published: January 2013

A simulation study of a coldâ€“flow in coaxial pipes was carried out with varying drivepipe diameter and entrance displacement (Î”L). The current work has studied the effect of the temperature of the entrance flow inlet with variation of Î”L to he entrained flow characteristics. To predict these flow characteristics, a numerical method was employed by the differencing scheme for integrating the continuity equation and energy equation. A kâ€“Îµ turbulent model was used to simulate the turbulent transport quantities. The 2â€“D flow pattern was created as the result of using Fluent 4.4 CFD modeling package. Results showed that increasing the air entrained temperature until 600 K would decrease the airflow rate. It was found that the diameter ratio of 2.81 has the highest entrained flow rate.
Fire Safety in Buildings
Authors: Walls Kelvin L
Published: January 2013

Many building, in many countries, throughout the world have substandard fire safety features. This discussion is restricted to hotels and hostels, which are often the only types of buildings readily accessible by visitors to a country. It attempts to explore some of the difficulties in that many building regulatory agents in some countries are not ensuring all building are safe from fire. It recommends that in the absence of fully safe buildings from the statutory approval process, private consortia of building owners should be initiating their own safety checklists.

Key words: Fire safety; non-compliance; unsafe buildings; building codes; means of escape.
Numerical Modelling of Thermo–Hydro–Mechanical (THM) in Deforming Porous Media for Subsurface Systems
Authors: Abd. Rahman Norhan , Kamaruddin Samira Albati , Schrefler Bernhard A.
Published: January 2013

Kajian aliran berbilang–fasa dan aliran haba dalam bahantara berliang separa tepu menjadi semakin penting dalam kejuruteraan geomekanik persekitaran kerana ia berkait rapat dengan pengukuhan bahantara berliang itu di dalam zon tidak tepu. Satu model berangka telah dikembangkan untuk menghuraikan masalah terganding haba–hidro–mekanikal (THM) dalam bahan berliang boleh ubah bentuk dengan aliran dua–fasa. Hubungan yang disarankan oleh Brooks dan Corey telah digunakan kepada tekanan rerambut, ketepuan air dan kebolehtelapan air serta gas. Satu kajian lanjutan dibuat ke atas model berangka tersebut berasaskan kod COMES–GEO untuk menyelesaikan masalah yang berlaku dalam zon tak tepu di medan telaga Kg. Puteh, Kota Bharu, Kelantan iaitu sebuah akuifer cetek yang berpotensi untuk mengeluarkan bekalan air bumi terbanyak di daerah Kota Bharu. Untuk menunjukkan model dan prosedur penyelesaiannya, rumusan pelaksanaan berangka dan contoh–contoh masalah dibincangkan di dalam kajian ini.

Kata kunci: Aliran berbilang-fasa; aliran haba; bahan berliang boleh ubah bentuk; model berangka;zon tidak tepu; haba-hidro-mekanikal.

The study of multiphase flow and heat flow in partially saturated porous media is important in environmental geomechanics engineering because of its relevance to consolidation of porous media in unsaturated zone. A numerical model which describes the thermo–hydro–mechanical (THM) coupled problems in deformable porous material with two–phase flow has been developed. The relationships between capillary pressure, saturation of water and relative permeabilities of water and gas, proposed by Brooks and Corey was used. An extended study of the numerical model, based on the COMES–GEO code was conducted recently to solve unsaturated problems in local condition of Kg. Puteh wellfield, Kota Bahru. This site is a potential shallow aquifer which contribute to the largest groundwater supply in Kota Bahru, Kelantan. Some numerical investigation on the proposed formulation is discussed with illustrative example problems to demonstrate solution procedures and validating of the model.

Key words: Multiphase flow; heat flow; deforming porous media; numerical model; unsaturated zone; thermo-hydro-mechanical.
Art of Woodcarving in Timber Mosques of Peninsular Malaysia and Southern Thailand
Authors: Said Ismail
Published: January 2013

Woodcarving in vernacular timber mosques of Peninsular Malaysia and Southern Thailand is a manifestation of a craftsman's idea into a piece of timber. It is a craft that is generated and nurtured form careful observation by the Malay craftsman towards the surrounding landscape elements particularly of plant forms. The manifestation is always in abstraction, symbolizing the plant feature or geometry into three types of architectural components, namely, structural, elemental and ornament. Cengal timber is the favorite hardwood species for carving which is carved either in relief or perforated manner. The significant effect of woodcarving in the mosque is that it enhances beauty and introduces symbolism to the vernacular architecture of the Pattani region. Although the skills of this craft are fast diminishing in the present Malay society, its revival could be generated through informing the public about the beauty of the craft.

Keywords: woodcarving; vernacular mosques; motif; craftmen.
Comparison of the Amino Acid Sequence of L–Mandelate Dehydrogenase From Rhodotorula Graminis With Other L–2–Hydroxyacid Dehydrogenase Enzyme and its Primary Structure Prediction
Authors: Md. Illias Rosli , A. Reid Graeme , A. Wahab Nadzarah
Published: January 2013

Perbandingan struktur primer L(+)–mendalate dehydrogenase (L–MDH) daripada yis Rhodotorula graminis dengan protein lain di dalam bank data protein menunjukkan persamaan di antara protein ini dengan kumpulan enzim L–2–hidroksiasid dehidrogenase. LMDH daripada R. graminis mempamerkan kesamaan antara 26–42% kepada L–lactate dehidrogenase daripada Sacchomoryces cerevisiae, L–lactate dehidrogenase daripada Hansenula anomala, glikolat oksida daripada bayam, L–laktat dehidrogenase daripada Escherichia coli, LMDH daripada Psedomonas putida dan laktat–2 monooksigenase daripada Mycobakterium smegmatis. Asid amino yang penting secara strukturnya bagi LMDH diramalkan secara perbandingan dengan bahagian penting domain sitokram dan domain perlekatan FMN yang diperoleh daripada struktur tiga dimensi L–laktat dehidrogenase daripada Sacchoromyces cerevisiae.

Kata kunci: L-MDH; Rhodotorula gramisis; L(+)-mandalate dehydrogenase; asid amino,flavocytochrome b2

A comparison of the primary structure or L–mandelate dehydrogenase (L–MDH) from Rhodotorula graminis with other proteins from the protein databank suggests that there is similarity between this protein and L–2–hydroxyacid dehydrogenase enzymes. R graminis LMDH exhibits 26–42% identity to L–lactate dehydrogenase from Saccharomyces cerevisiae, L–lactate dehydrogenase from Hansenula anomala, glycolate oxidase from spinach, L–lactate dehydrogenase from Escherichia coli, L–mandelate dehydrogenase from Pseudomonas putida and lactate–2–monooxygenase from Mycobacterium smegmatis. Structurally conserved amino acids are predicted from LMDH sequences corresponding to important regions of the cytochrome and FMN–binding domain defined from the known three–dimensional structure of the L–lactate dehyrogenase from Sacchoromyces cerevisiae.

Key words: L-MDH; Rhodotorula graminis; L-mandelate dehydrogenase; amino acid;flavocytochrome b2
Mathematics Education at Universiti Teknologi Malaysia (UTM): Learning from Experience
Authors: Mohd Yusof Yudariah , Abdul Rahman Roselainy
Published: January 2013

Kertas kerja ini akan menerangkan perkembangan pendidikan matematik di UTM. Suatu tinjauan berkaitan dengan masalah pembelajaran dan pengajaran matematik dalam dekat yang lalu akan dibincangkan. Beberapa strategi telah dilaksanakan untuk menangani permasalahan pelajar. Mengurangkan jurang perbezaan kebolehan antara pelajar serta memudahkan peralihan dari sekolah ke pendidikan peringkat tinggi. Suatu ringkasan tentang program–program tersebut akan diberikan.

Beberapa perubahan yang berlaku kini akan memberi kesan kepada hala tuju pendidikan di UTM. Terdapat peningkatan dalam bilangan pengambilan pelajar, usaha ke arah menyepadukan media elektronik dalam pengajaran dan pengembangan pendidikan maya yang akan membuka ruang yang lebih luas kepada pendidikan. Khususnya, bagi pendidikan matematik, perubahan ini akan mempengaruhi perkembangan kurikulum, kaedah pengajaran dan penilaian pembelajaran matematik.

Oleh yang demikian, inilah senario pendidikan di UTM – dalam sistem akademik yang sedia ada, dengan masalah yang belum selesai, pendekatan–pendekatan yang telah dilaksanakan dan ada yang diketepikan, strategi baru diperkenalkan secara berkala, dan kini terdapat pula perubahan dan perkembangan baru yang perlu dihadapi. Pengalaman lalu harus dimanfaatkan untuk menyediakan garis panduan bagi pendidikan matematik di UTM pada masa hadapan.

This paper will describe mathematics education in UTM. A review of the problems faced in the learning and teaching of mathematics in the last decade will be discussed. Several academic strategies have been implemented in the past, aimed at overcoming students’ learning difficulties, narrowing the abilities gap among the students, as well as facilitating the transition from secondary to tertiary learning. A summary of these programmes will be presented.

There are now changes taking place that will further impact the direction of education in UTM. There is an increase in the number of students intake, a movement towards integrating the use of electronic media in teaching and an expansion of virtual education to ensure a wider access to education. In particular, for mathematics education, these changes will affect the curriculum development, the teaching methods and the assessment of mathematics learning.

Thus the scenario in UTM is set–within the existing academic system, the old problems still persist, approaches have been undertaken and discarded, new strategies implemented periodically and there are now new changes and development to be faced. These experiences must be taken into consideration in order to develop guidelines for future mathematics education in UTM.
Peningkatan Kualiti Reka Bentuk Kerusi Sekolah Rendah dengan Mengintegrasikan Kaedah QFD dan Kejuruteraan Nilai
Authors: Mohd. Rohani Jafri , Tamat Suhaimi
Published: January 2013

Kajian ini adalah untuk mengintegrasikan kaedah QFD (Quality Function Deployment) – Pembangunan Fungsi Kualiti dan kaedah VE (Value Engineering) – Kejuruteraan Nilai dalam mereka bentuk kerusi sekolah rendah berasaskan kayu. Tujuan sebenar QFD adalah untuk membolehkan keperluan terhadap kehendak pengguna (pelajar sekolah rendah) diterjemahkan kepada kehendak teknikal dan reka bentuk. Pada hakikatnya pengguna mempunyai bahasa mereka yang tersendiri dalam menyampaikan maksud kehendak mereka, manakala jurutera reka bentuk pula mempunyai bahasa mereka tersendiri yang terdiri daripada bentuk–bentuk teknikal bagi memenuhi kehendak pengguna tersebut. Dalam melaksanakan proses translasi antara dua maklumat yang berbeza ini, pendekatan yang bersistematik perlu digunakan bagi menukar maklumat kualitatif dan kuantitatif pengguna kepada kriteria–kriteria teknikal yang diperlukan untuk reka bentuk. Pendekatan bersistematik tersebut boleh diperoleh melalui proses QFD, iaitu maklumat–maklumat tersebut akan dijanakan melalui beberapa matrik utama. Dalam kajian ini, kaedah VE telah diaplikasikan untuk menyenarai tapis kriteria yang dipindahkan dari Matrik Rumah Kualiti (matrik pertama) kepada Matrik Perancangan Komponen (matrik kedua) dalam kaedah QFD. Keputusan kajian menunjukkan bahawa kehendak pengguna iaitu pelajar sekolah rendah dapat dipenuhi melalui integrasi kaedah QFD dan VE iaitu kerusi sekolah rendah berasaskan kayu yang menepati ciri–ciri kepenggunaan telah dikenalpasti, yang meliputi aspek kejuruteraan reka bentuk.

Kata kunci: Pembangunan Fungsi Kualiti; Kejuruteraan Nilai
Pemodelan Pembangunan Guna Tanah Komersial Menerusi Aplikasi Sistem Maklumat Geografi (GIS) Kes Kajian: Seberang Perai Tengah, Pulau Pinang
Authors: Dziauddin Mohd Faris , Rainis Ruslan
Published: January 2013

Artikel ini menerangkan pembangunan model ruangan bagi pembangunan guna tanah komersil. Model yang dibangunkan ini bertujuan mendiskriminasikan kawasan yang membangun sebagai kawasan komersil, pembangunan–pembangunan lain dan kawasan yang tidak membangun. Teknik statistik yang dipanggil Analisis Diskriminan digunakan bagi tujuan pembangunan model. Terdapat sebelas pembolehubah ruangan dimasukkan ke dalam model termasuklah kehampiran ke kawasan komersil, kehampiran ke kawasan perumahan, kehampiran ke kawasan industri, kehampiran ke bandar, kehampiran ke jalan raya, nisbah jiran yang membangun, peratus jiran yang membangun sebagai kawasan komersil, peratus jiran yang membangun sebagai kawasan perumahan, peratus jiran yang membangun sebagai kawasan industri dan kehampiran ke kawasan pertanian. Bagi tujuan kajian, dua set data dibangunkan iaitu bagi tempoh tahun 1992–1994 dan 1995–1998. Sistem Maklumat Geografi digunakan bagi menjana semua pembolehubah–pembolehubah ruangan. Pembangunan model adalah berdasarkan kepada data perubahan guna tanah bagi tempoh tahun 1992–1994 manakala pengujian model berdasarkan kepada data bagi tempoh tahun 1995–1998. Ketepatan yang diperoleh daripada model asal ialah 74.9%. Daripada pengujian yang dilakukan, didapati model ini telah berjaya meramal perubahan guna tanah dari tabun 1995–1998 dengan ketepatan 98.6%.

Kata kunci: Pemodelan guna tanah guna tanah komersil; sistem maklumat geografi (GIS); analisis diskriminan

The article describes the development of a spatial model for commercial land use development. A statistical model called the Discriminant Analysis was used to discriminate between areas developed for commercial purpose, urban developments and undeveloped areas. Eleven spatial variables related to proximily and neighbourhood development were considered in the model. For this particular study data were developed for the period of 1992-1994 and 1995–1998, using the Geographic Information System to generate the spatial variables. The development of model based on changes of land used for 1992–1994 was verified against the data obtained for 1995–1998. The model yields a highly accurate prediction of the variation in the commercial land use development.

Key word: Land use modeling; commercial land use; geographic information system (GIS); discriminant analysis
Analisis Struktur dan Spesies Permukaan Terhadap Kereaktifan Mangkin Oksida Mangan–Timah
Authors: Ahmad Mohd. Tahir , Wan Abu Bakar Wan Azelee , Buang Nor Aziah
Published: January 2013

Oksida timah (IV) dengan kehadiran bahan pendop memperlihatkan pelbagai aktiviti yang menarik untuk dikaji dengan mendalam. Dalam kajian ini oksida timah (IV) didopkan dengan Mn(II) dan Mn(IV) pada pelbagai nisbah komposisi dan suhu pengkalsinan menggunakan kaedah pengisitepuan. Bagi melihat aktiviti pemangkinan, sampel mangkin diuji menggunakan sistem reaktor mikro padatan tetap yang menghampiri keadaan sebenar ekzos kenderaan bermotor. Hasil ujian menunjukkan sampel mangkin yang didopkan dengan Mn(II) pada nisbah komposisi 40:60 berpotensi sebagai mangkin dua arah yang setanding dengan mangkin komersil, Pt/AI2O3 dan Hopcalite (CuMn2O4). Pengoksidaan lengkap 100% (T100) berlaku pada suhu yang rendah iaitu T100 = 100°C bagi gas CO dan T100 = 300°C bagi gas propana. Bagi memahami kaitan struktur dan keupayaan pemangkinan sampel mangkin, dua teknik pencirian dilakukan iaitu XPS dan XRD. Pencirian melalui teknik XPS mengenalpasti oksida mangan wujud dengan nombor pengoksidaan +2 dan +3 pada suhu pengkalsinan 400 dan 600°C. Kewujudan nombor pengoksidaan tersebut disahkan melalui teknik XRD iaitu bagi oksida mangan disumbang oleh Mn2O3 dan spinel Mn3O4. Didapati aktiviti pemangkinan yang terbaik bagi sampel mangkin ialah apabila sampel mangkin berada dalam percampuran kedua–dua nombor pengoksidaan tersebut. Daripada teknik XRD juga didapati darjah kehabluran sampel mangkin meningkat apabila suhu pengkalsinan ditingkatkan.

Kata kunci: Aktiviti pemangkinan; XPS dan XRD

Tin(IV) oxide when doped with other metal oxides exhibit interesting activities to be studied further. In this research, tin(IV) oxide was doped with Mn(II) and Mn(IV) at various composition ratios and calcination temperatures using an impregnation method. The catalytic performance of the prepared sample were investigated using a fixed bed micro-reactor system which resembled the actual exhaust gas condition. For catalyst sample doped with Mn(II) 40:60, the catalytic results have shown their potential as 2–way catalyst that are comparable with the commercial catalyst (Pt/AI2O3 and Hopcalite (CuMn2O4). Catalyst sample gave a 100% conversion (T100) at a low temperature of T100 = 100°C for CO and T100 of 300 for C3H8. To verify the relationship between the structures of the catalyst sample with their catalytic capabilities, characterisation analysis by XPS and XRD were performed. XPS analysis recalled the existence of manganese oxides with oxidation numbers of +2 and +3 at calcination temperatures of 400 and 600°C. This finding is supported by XRD analysis which showed that the manganese oxide was contributed by Mn2O3 and spinel Mn3O4. Therefore the best catalytic activities could be achieved with a catalyst sample prepared under a mixture of the two oxidation numbers. More over from the XRD technique, the degree of crystalinity of the catalyst sample increase as the calcination temperature increases.

Key words: Catalytic activity; XPS and XRD
Degradasi Larutan Pewarna Azo Tekstil Menggunakan Sistem Heterogenan O3, O3/UL, O3/TiO2/UL dan O3/H2O2/UL
Authors: Ali Razak , Wan Abu Bakar Wan Azelee , Aris Azmi , Mok Pak Yan
Published: January 2013

Rawatan larutan pewarna azo tekstil, Sumifix Supra Blue BRF 150% Gran (SSBBRF) melibatkan sistem yang berbeza, O3, O3/UL, 03/TiO2/UL dan O3/H2O2/UL telah dikaji. Keputusan yang diperoleh menunjukkan bahawa degradasi larutan SSBBRF melalui sistem pengoksidaan berasaskan ozon adalah lebih efektif berbanding dengan sistem pemangkinanfoto. Darjah degradasi keserapan dan warna yang tinggi serta degradasi COD dan TOC yang ketara, menunjukkan bahawa sistem pengoksidaan yang berasaskan ozon berupaya memecahkan pewarna azo dalam air tercemar kepada spesies yang lebih terbiorawat. Keputusan yang diperoleh juga menunjukkan bahawa sistem pengozonan (O3 sahaja dalam keadaan gelap), dan sistem gandingan pengozonanfoto–pemangkinanfoto (03/TiO2/UL) tidak menunjukkan perbezaan kadar degradasi pewarna azo yang ketara berbanding sistem pengozonanfoto (O3/UL) tetapi penambahan hidrogen peroksida (H2O2) ke dalam sistem 03/UL mampu meningkatkan lagi kadar degradasi pewarna azo. Perbandingan keupayaan sistem yang dikaji bagi degradasi pewarna SSBBRF adalah mengikut urutan: 03/H202/UL > O3/UL > O3/TiO2/UL > O3 > TiO2/UL. Proses pendegradasian pewarna SSBBRF mematuhi kinetik tindak balas tertib pertama pseudo dengan nilai pemalar kadar, k, dari julat 0.20 min–1 hingga 0.24 min–1 untuk 20 minit yang pertama.

Kata kunci: Pewarna azo; pengozonanfoto; pemangkinanfoto; hidrogen peroksida

Treatment of aqueous textile azo dye, Sumifix Supra Blue BRF 150% Gran (SSBBRF) by different kinds of systems, 03, O3/UV, 03/TiO2/UV and O3/H2O2/UV has been investigated. The results obtained showed that the degradation of SSBBRF solution involving ozone–assisted oxidation system is more superior compared to photocatalytic system. The high degradation degree of Absorbance and colour as well as the significant degradation of COD and TOC indicated that the ozone–assisited system is capable of disrupting the azo dye in the wastewater to more biotreatable species. The results obtained, also showed that ozonation (O3 alone in dark) system and simultaneous photoozonation–photocatalytic (03/TiO2/UV) system do not give significant effect to the degradation rate of azo dye in comparison with photoozonation (O3/UV) system, but addition of hydrogen peroxide (H202) in the O3/UV system may enhance the degradation rate of the azo dye. The degradation potential of these different systems studied towards SSBBRF are in the following the order: O3/H2O2/UV > O3/UV > 03/TiO2/UV > O3 > TiO2/UV. The degradation process of SSBBRF is following the kinetic of pseudo–first order reaction with the rate constants, k, ranging from 0.20 min–1 up to 0.24 min–1 for the first 20 minutes of the reactions.

Key words: Azo dye; photoozonation; photocatalysis; hydrogen peroxide
Kajian Ke atas Parameter Model Rangkaian Rambatan Balik untuk Peramalan: Kajian Kes Hasil Pengeluaran Getah
Authors: Sallehuddin Roselina , Hj. Shamsuddin Siti Mariyam
Published: January 2013

Kertas kerja ini membincangkan metodologi dan parameter berkaitan yang perlu diambilkira apabila melibatkan proses peramalan menggunakan teknik rambatan balik. Lazimnya, kejituan peramalan banyak dipengaruhi oleh pemilihan parameter iaitu pemalar pembelajaran (pemalar momentum (b) dan kadar pembelajaran (a)), bilangan nod tersembunyi dan jenis fungsi keaktifan. Ketidaksesuaian nilai parameter dan bilangan nod di aras tersembunyi akan menyebabkan rangkaian memberi jawapan yang mencapah daripada sasaran sebenar. Oleh yang demikian, penulis cuba mengkaji nilai parameter yang bersesuaian, perkaitan yang wujud di antara parameter tersebut serta kesannya terhadap prestasi ramalan model rambatan balik. Parameter yang dicadangkan ini diuji ke atas data pengeluaran hasil getah daripada tahun 1989 sehingga 1998.

Kata kunci: Peramalan; Rambatan balik; Parameter Pembelajaran; Momentum; Nod Tersembunyi

This paper discusses the methodology and parameters that need to be considered when using backpropagation model for forecasting. Usually, the accuracy of forecasting depends on several parameters such as learning parameters (momentum constant (b) and learning rate (a)), number of hidden nodes and type of activation function used. When the values of learning parameters and the number of hidden nodes are not suitable, the resulted values are diverged from the actual target values. Therefore, in this study, we investigate the compatible values of learning parameters, their relationships and the effectiveness on forecasting performance. The suggested parameters are tested on data of rubber production from the year 1989 to 1998.

Key words: Forecasting; Backpropagation; Learning Parameter; Momentum; Hidden Nodes
Kajian Sekat Gerak Bakteria Berpenyokong dalam Pengambilan Semula Logam Cu dan Zn
Authors: Haron Roslindawati , Zakaria Zainul Akmar , Ahmad Wan Azlina
Published: January 2013

Kajian pengambilan semula logam Zn dan Cu telah dilakukan menggunakan teknik sekat gerak dengan bakteria A dan P sebagai biopenjerap dan pasir terawat asid sebagai matrik penyokong. Hampir 99% bakteria A dan 100% bakteria P berjaya disekat gerak pada pasir. Nilai qmarks. (Zn: 205.6 mg/g bagi bakteria A dan 58.2 mg/g bagi bakteria P, Cu: 23.2 mg/g bagi bakteria A, dan 13.3 mg/g bagi bakteria P) yang diperoleh menunjukkan bahawa pengambilan logam lebih baik pada pH 4.5. Pengelusian Zn dan Cu yang dilakukan menggunakan 0.05M HNO3 hanya berjaya mengeluarkan lebih kurang 40% Zn dan 30% Cu.

Kata kunci: Tersekat gerak; zink; kuprum; penyahjerapan; bakteria

A study on the ability of immobilized bacteria A and P to enhance the recovery of Cu and Zn was carried out. Almost 99% of bacteria A and 100% of bacteria P were successfully immobilized on the sand. qmax values obtained for Cu and Zn was 23.2mg/g (bacteria A), 13.28mg/g (bacteria P) and 205.6mg/g (bacteria A), 58.2mg/g (bacteria P) respectively. From the desorption experiment, about 33% of Cu and 41% of Zn were recovered. In conclusion, the uptake of Cu and Zn was higher at pH 4.5, whilst HNO3 (0.05M) was not a suitable eluting agent to release adsorped Cu and Zn.

Key words: Immobilized; zink; copper; bacteria
Ciri Kerja dan Prestasi Profesional Teknologi Maklumat Sektor Awam Malaysia
Authors: Mohamad Noor Azmi , Wan Ismail Wan Faridah Akmal , Omain Siti Zaleha
Published: January 2013

Kajian ini mengkaji ciri kerja dan prestasi profesional Teknologi Maklumat di Unit/Bahagian Perkhidmatan Maklumat sektor awam Malaysia. Ciri kerja dianalisis melalui Model Ciri Kerja oleh Hackman dan Oldham. Prestasi kerja pula dianalisis berpandukan Borang Pengenalpastian Perlakuan yang dipermudahkan, asalnya dibina oleh Botterbusch pada tahun 1985. Hubungan ciri kerja dengan prestasi diselidiki menggunakan ujian Mann–Whitney U. Ciri kerja menunjukkan tahap tinggi dalam kepentingan tugas dan keperluan bekerjasama dalam menjalankan tugas tetapi dengan tahap rendah dalam autoriti tugas. Prestasi kerja yang tinggi ialah dalam produktiviti dan perlakuan sosial dan yang rendah pula dalam tabiat/sikap kerja. Kajian ini mendapati terdapat hubungan bererti antara ciri kerja dan prestasi di kalangan profesional Teknologi Maklumat sektor awam Malaysia.

Kata kunci: Ciri kerja; prestasi kerja; teknologi maklumat; sektor awam

This study analyzed job characteristics and performance of Information Technology professionals at the Information Technology centers of the public sector of Malaysia. Job characteristics were analyzed based on the Job Characteristics Model by Hackman and Oldham. Performance on the other hand was analyzed using a simplified Behavior Identification Form, originally developed by Butterbusch in 1985. The relationship between job characteristic and performance was determined using the Mann–Whitney U test. Job characteristics showed a high score on job significance and dealing with others but low on task authority. Job performance showed high productivity and high social behavior but low on work habit and attitudes. This research found that there is a significant relationship between job characteristics and performance of Information Technology professionals of the Malaysian public sector departments.

Key words: Job characteristics; job performance; information technology; public sector departments
Injection Moulding of A Bimodal Size Distribution 316L Stainless Steel Powders
Authors: Omar M.A.
Published: January 2013

Bagi mengurangkan kos bahan mentah untuk proses pangacuan suntikan logam (MIM), bahan teracu yang diperbuat daripada serbuk logam keluli tahan karat dengan nisbah serbuk logam kasar dan halus yang berlainan telah diselidiki. Bahan suapan tersebut disediakan dengan menggunakan sistem bahan pengikat komposit yang terdiri sebahagian besarnya polietilina glikol (PEG) yang berlainan berat molekulnya dan emulsi polimetil metakrilat (PMMA) yang seterusnya disuntik ke dalam bentuk segiempat tepat dengan suhu muncung suntikan logam pada 140°C. Hasil ujikaji menunjukkan kekuatan bahan teracu meningkat secara linear dengan peningkatan nisbah serbuk halus di dalam campuran dan optimum pada 30 wt.% dan seterusnya berlaku penurunan dengan peningkatan nisbah serbuk halus. Peningkatan serbuk logam halus di dalam campuran juga dapat meningkatkan ketumpatan akhir dan kekerasan bahan tersinter. Kadar penyingkiran polietilina glikol semasa proses pengurasan air meningkat dengan penurunan nisbah serbuk logam halus yang mana menunjukkan bahawa serbuk logam kasar memberi kesan ketara ke atas proses penyingkiran bahan pengikat.

Kata kunci: pengacuan suntikan logam; polietilina glikol; polimetil metakrilat; pengurusan air; pengsinteran

In an effort to lower the cost of raw materials of metal injection moulding (MIM), a moulded part made of a different ratio of coarse and fine stainless steel powder mixtures, ranging from 10 to 50 wt.% of fine powder were investigated. The feedstocks were prepared using a composite binder system which consist of a major fraction of polyethylene glycol (PEG) with different molecular weight and a minor fraction of polymethyl methacrylate (PMMA) emulsion and subsequently moulded into a rectangular shape at the nozzle temperature of 140°C. The results show that the green strength of the moulded part increased linearly with the increased of the ratio of fine powder to an optimum of 30 wt.% and decreased slightly with the increased of coarse/fine ratio. An increase in the fine powder in the mixture, improved the final densification and hardness of the sintered parts. The rate of PEGs removed during water leaching substantially increased with the lower ratio of fine powder, which suggest that the coarse powder has significant influence on the removal of the binder.

Key words: metal injection moulding; polyethylene glycol; polymethyl methacrylate; water leaching; sintering
Radial Basis Function (RBF) for Non–Linear Dynamic System Identification
Authors: Ahmad Robiah , Jamaluddin Hishamuddin
Published: January 2013

Masalah utama dalam pengenalpastian sistem ialah memilih struktur model yang sesuai. Dalam artikel ini, rangkaian fungsi asas jejarian menggunakan pelbagai fungsi asas dilatih untuk mewakili sistem dinamik tak linear masa diskrit dan keputusannya dibandingkan. Algoritma kuasa dua terkecil ortogon digunakan untuk memilih model rangkaian asas jejarian termudah. Untuk menerangkan tatacara pengenalpastian, dua contoh pemodelan sistem tak linear dibincangkan.

Kata kunci: fungsi asas jejarian; pengenalpastian sistem; pemodelan sistem tak linear; algoritma kuasa dua terkecil ortogon

One of the key problem in system identification is finding a suitable model structure. In this paper, radial basis function (RBF) network using various basis functions are trained to represent discrete-time nonlinear dynamic systems and the results are compared. The orthogonal least square algorithm is employed to select parsimonious RBF models. To demonstrate the identification procedure, two examples of modelling nonlinear system were included.

Key words: radial basis function; system identification; non-linear system modelling; orthogonal least square algorithm
Penganggaran Kekardinalan Set Penyelesaian Persamaan Kongruen
Authors: Sapar Siti Hasana , Mohd Atan Kamel Ariffin
Published: January 2013

Katakan X = (x1, x2, ...., xn) suatu vektor dalam ruang Zn dengan Z menandakan gelanggang integer. Katakan q integer positif dan f suatu polinomial dalam X berpekalikan unsur dalam Z. Hasil tambah eksponen yang disekutukan dengan f ditakrifkan sebagai yang dinilaikan bagi semmua nilai x di dalam set reja lengkap modulo q. Nilai S (f;q) adalah bersandar kepada penganggaran bilangan unsur |V| yang terdapat dalam set V = {X mod q | fx ? 0 mod q} dengan fx menandakan polinomial-polinomial terbitan separa f terhadap X = (x1, x2, ...., xn). Dalam makalah ini perbincangan kami ditumpukan kepada kaedah penganggaran |V| yang disekutukan dengan polinomial f dalam dua pemboleh ubah (x , y) berpekali integer. Perbincangan dimulakan dengan polinomial f yang linear dan seterusnya meningkat sehingga polinomial f berdarjah tiga. Pendekatan yang dilakukan ialah dengan menggunakan kaedah p-adic dan Polihedron Newton yang disekutukan dengan polinomial-polinomial terbabit.

Kata kunci: penganggaran kekardinalan; persamaan kongruen; kaedah p-adic; kaedah polihedron Newton

Let X = (x1, x2, ...., xn) be a vector in a space Zn with Z ring of integers and let q be a positive integer and f a polynomial in X with coefficients in Z. The exponential sum associated to f is defined as , where the sum is taken over a complete set of residues modulo q. The value of S (f;q) depends on the estimation of the number |V|, the number of elements contained in the set V = {X mod q | fx ? 0 mod q} with fx as the partial derivative of f with respect to X = (x1, x2, ...., xn). This paper discusses the problem of determining the common zeroes of two variable polynomials in cases where overlapping occurs at vertices and line segments of indicator diagrams associated with second and third degree polynomials. Subsequently estimations for of an exponential sum for these polynomials are arrived at. The approach is done by using p-adic method and the Newton Polyhedron technique associated with these polynomials

Key words: Cardinality estimation; congruence equation; p-adic method; newton polyhedron technique
Friedelâ€“Crafts Acylation of Anisole Catalysed by Hâ€“Zeolite Beta of Crystalline Rice Husk Ash
Authors: Ramli Zainab , Prasetyoko Didik , Endud Salasiah
Published: January 2013

Kereaktifan zeolit H-Beta yang disintesis secara terus daripada abu sekam padi berhablur dengan berbagai-bagai nisbah SiO2/Al2O3 gel dikaji dalam pengasilan Friedel-Crafts anisol dengan propionik anhidrida. Tindak balas dilakukan dalam reaktor kelompok pada berbagai-bagai suhu dan masa tindak balas untuk mendapatkan keadaan optimum. Hasil tindak balas yang dianalisis menggunakan kaedah gas kromatografi menunjukkan p-metoksipropiofenon adalah hasil utama di samping asid propionik sebagai hasil sampingan. Mangkin H-Beta daripada nisbah gel SiO2/Al2O3 = 27 menunjukkan keaktifan tertinggi dengan peratus pertukaran anisol 88.9% dan kepilihan terhadap p-metoksipropiofenon 75.3%. Keadaan optimun pengasilan adalah pada suhu 100Â°C dalam masa 4 jam. Kajian menunjukkan mekanisme pengasilan adalah penukargantian elektrofilik aromatik yang dimangkinkan oleh tapak asid Brnsted daripada zeolit H-Beta.

Kata kunci: beta zeolite; abu sekam padi; penghasilan Friedel-Crafts; anisol

The reactivity of H-Beta zeolite, synthesised directly from crystalline rice husk ash in various SiO2/Al2O3 gel ratios, was studied in the Friedel-Crafts acylation of anisole with propionic anhydride. Reactions were carried out in a batch reactor at various times and reaction temperatures in order to obtain the optimum acylation condition. Products identified by gas chromatography showed that p-methoxypropiophenone is the main product with propionic acid as the main side product. H-Beta catalyst from the SiO2/Al2O3 = 27 gel ratio gave the highest activity, with anisole conversion of 88.9% and product selectivity toward p-methoxypropiophenone of 75.3%. The optimum acylation condition was taken at 100Â°C reaction temperature in 4 hour reaction. Study showed that acylation reaction follows the electrophilic aromatic substitution mechanism catalysed by Brnsted acid sites of H-Beta zeolite.

Key words: zeolite beta; rice husk ash; Friedel-Crafts acylation; anisole
Hysteresis Behaviour of Sensitivity In CH4 Detection in Air Using SnO2 with Pd as Sensitizing Additive
Authors: Dennis John Ojur , Abd. Karim Mohd Mustamam , Ibrahim Zuhairi , Saidin Mohd Khairi
Published: January 2013

Kepekaan SnO2 dengan Pd sebagai bahan tambah menunjukkan sifat histerisis apabila pengukuran dilakukan pada suhu operasi menaik berbanding dengan pengukuran yang dilakukan pada suhu menyusut. Kepekaan sampel-sampel dikira bagi beberapa suhu operasi dari 200Â°C sehingga 430Â°C dan didapati kepekaan meningkat apabila pengukuran yang dilakukan pada suhu menurun. Histerisis yang diamati dalam kepekaan ini dibincangkan dalam konteks jenis spesies oksigen yang terjerap di atas permukaan SnO2.

Kata kunci: histerisis; kepekatan; bahan tambah pemekaan; konduktans; metana

The sensitivity of SnO2 with Pd as an additive showed a hysteresis behaviour when measurement was carried out as the operating temperature is increasing compared to measurement with decreasing temperature. The sensitivities of the samples that were calculated at the various operating temperatures from 200Â°C to 430Â°C were found to be higher when measuring with decreasing temperature. This observed hysteresis in sensitivity is discussed in terms of the type of oxygen species adsorbed on the SnO2 surface.

Key words: hysterisis; sensitivity; sensitizing additive; conductance; methane
Superglue Fuming for the Chemical Enhancement of Latent Fingerprints
Authors: Ahmad Umi K. , Musa Afizah
Published: January 2013

Penerimaan bukti cap jari oleh mahkamah lazimnya berdasarkan kepada anggapan bahawa tiada dua individu mempunyai cap jari yang sama. Cap jari nampak atau cap jari pendam sering dijumpai di tempat kejadian jenayah. Walau bagaimanapun, cap jari pendam adalah sukar dikesan dan memerlukan penggunaan teknik yang dapat memperlihatkan kesan cap jari. Kajian ini melibatkan penggunaan teknik kimia bagi penyerlahan cap jari pendam. Kaedah pewasapan gam jenis superglue dibandingkan dengan dua kaedah lain menggunakan reagen ninhidrin dan eosin. Penyerlahan bagi ketiga-tiga kaedah didapati bergantung kepada jenis permukaan yang mengandungi cap jari. Keputusan menunjukkan bahawa pewasapan superglue dan teknik eosin berupaya menyerlahkan cap jari pendam pada permukaan tidak berliang yang telah disimpan sehingga tiga bulan. Teknik ninhidrin pula didapati berkesan bagi cap jari pendam pada permukaan yang berliang.

Kata kunci: Cap jari pendam; Pewasapan superglue; ninhidrin; eosin

The acceptance of fingerprint evidence by the courts has always been predicated on the assumption that no two individuals have identical fingerprints. Fingerprints (visible or latent) are often found at a scene of crime. Latent prints however, are difficult to locate and require the utilization of techniques that will visualize the prints. This study involved the application of chemical techniques to the visualization of latent fingerprints. The more recent superglue fuming technique was compared to two other techniques using ninhydrin and eosin as chemical reagents. The chemical enhancement of the three techniques was found to be dependent upon the nature of the surface on which the prints were deposited. Results showed that superglue fuming and eosin technique were capable of enhancing latent fingerprints on non-porous surfaces which have been kept for up to three months. The ninhydrin technique was found to be effective only for latent fingerprints on porous surfaces.

Key words: latent fingerprints; superglue fuming; ninhydrin; eosin
A Graphical User Interface Application for Continuous-time Identification of Dynamical System
Authors: Rahmat Mohd. Fuaâ€™ad , Omar Rosli , Jamaluddin Hishamuddin
Published: January 2013

Kertas kerja ini memperkenalkan teknik grafik pengantaramukaan pengguna di dalam pengenalpastian sistem dan penganggaran parameter sistem menggunakan kaedah GPMF yang berdasarkan algorithma IV. GUI yang berdasarkan kepada perisian MATLAB ini mengandungi pra pemproses data, anggaran parameter, penentusah model dan simulasi model. Prosedur penggunaan GUI juga ditunjukkan dalam kajian ini. Proses penentusah model adalah menggunakan proses penentusahan silang. Proses simulasi yang berdasarkan kepada anggaran model matematik telah dilaksanakan untuk menganalisis ciriâ€“ciri dinamik model. Dari keputusan simulasi dan analisis didapati model matematik yang diperolehi adalah boleh dipercayai.

Kata kunci: GUI; pengenalpastian sistem; anggaran parameter; GPMF; IV

This paper introduces a Graphical User Interface (GUI) application in system identification and parameter estimation of dynamic systems using Generalized Poisson Moment Functionals (GPMF) method based on Instrumental Variable (IV) algorithm. The GUI based on MATLAB consists of data preprocessing, parameter estimation, model validation and model simulation. A stepâ€“byâ€“step instruction on how to use the GUI employed in the study is also presented. A validation process had been implemented using cross validation process. Simulation process based on the estimated mathematical model was performed to analyze the dynamic behaviors of the model. From the simulation results and analysis, it could be concluded that the model obtained using this GUI is reliable.

Key words: GUI; system identification; parameter estimation; GPMF; IV
PI Sliding Mode Control for Mismatched Uncertain Systems
Authors: Md. Sam Yahaya , Osman Johari H.S. , A. Ghani Mohd. Ruddin
Published: January 2013

This paper focused on the proportionalâ€“integral sliding mode control for uncertain dynamic systems with mismatch uncertainties. First, the switching surface condition for the sliding mode control is synthesized. Then the control law is designed to drive the state trajectories of the system onto the sliding surface and the system remains in it thereafter. The proposed control law is applied to a numerical example and its performance is compared to the state variable feedback control system design methodology.

Key words: sliding mode control; state variable feedback regulator; mismatched uncertainties