bluuebunny/crossref_metadata_2025 huggingface dataset:
Topographic Distribution of the Different Cell Types, Connective Tissue and Vascular Tissue/Lumina Within a Functional Bovine Corpus Luteum and its Association with Breed, Type of Fixation Protocol and Stage During the Cycle
Authors: Cools S , Van den Broeck W , De Vliegher S , Piepers S , Hostens M , Opsomer G
Published: January 2013

Contents

In the present study, we analysed the effect of fixative, breed, luteal stage and location on the nuclear density, volume density of connective tissue and vascular tissue/lumina within a bovine luteal gland in view of the development of an in vivo sampling technique to longitudinally monitor luteal histophysiology. The inner zone defined as the zone geometrically closest to the centre of the gland shows a significantly lower nuclear density (for all cell types) and a higher volume density of collagen fibres and vessels when compared with the outer zone (p < 0.001). The nuclear density in luteal glands from Holstein‐Friesian cows is not significantly different from that in Belgian Blue cows, nor is it in stage II vs stage III glands. The collagen fibre content was significantly lower in glands of Belgian Blue cows (p = 0.01) and in younger glands (p = 0.003). Hence, it seems that the lower nuclear density in the inner zone was compensated by a higher amount of collagen fibres. As the type of fixative applied has a significant effect on the nuclear density of the different cell types, the present study warrants future research to further optimize the fixation protocol. As a conclusion, we can state that the topographic difference in nuclear distribution for the different cell types in a bovine luteal gland is only significant when comparing the inner vs the outer zone. This implies that if a sample representative for the whole gland has to be taken, for example, when taking an in vivo sample, it is necessary that the biopsy goes through the inner zone and contains the total diameter of the gland.
Task‐irrelevant own‐race faces capture attention: Eye‐tracking evidence
Authors: CAO RONG , WANG SHUZHEN , RAO CONGQUAN , FU JIA
Published: January 2013

To investigate attentional capture by face’s race, the current study recorded saccade latencies of eye movement measurements in an inhibition of return (IOR) task. Compared to Caucasian (other‐race) faces, Chinese (own‐race) faces elicited longer saccade latency. This phenomenon disappeared when faces were inverted. The results indicated that own‐race faces capture attention automatically with high‐level configural processing.
Risk and Policy Shocks on the US Term Structure
Authors: Weber Enzo , Wolters Jürgen
Published: January 2013

We document two stylized facts of US short‐term and long‐term interest rate data seemingly incompatible with the expectations hypothesis: low contemporaneous cross‐correlation and relatively slow adjustment to long‐run relationships. We explain these features in a small structural model with three types of randomness: While a persistent monetary policy shock implies immediate identical reactions through the term structure, both a transitory policy shock and an autocorrelated risk premium allow for sustained deviations. Indeed, we find important impacts and persistence of risk premia and considerable contribution of transitory policy shocks to short rates. Results of standard expectations hypothesis tests can be rationalized.
Effect Of Operating Parameters On The Minimum Fluidisation Velocity Of An Inclined Fluidised Bed
Authors: Taib Mohd. Rozainee , Kumoro Andri Cahyo
Published: January 2013

Fenomena kebendaliran pada lapisan terbendalir satah condong (IFB) masih di peringkat awalan dan kurang mendapat perhatian jika dibandingkan dengan lapisan terbendalir biasa walaupun terdapat banyak penerapan lapisan terbendalir yang tidak mengikut ciri lapisan terbendalir biasa. Tujuan kajian ini dilakukan adalah untuk menentukan kesan sudut kecondongan, saiz zarah dan komposisi zarah ke atas halaju kebendaliran minimum (Umf). Eksperimen ini dijalankan dengan menggunakan IFB segi empat tepat berdimensi 7 x 50 cm dilengkapi dengan distributor berketebalan 2 mm yang mempunyai lubang berdiameter 1 mm dan peratusan bukaan 2.98%, manometer air dan pemampat udara. Metode pengurangan berperingkat halaju udara masukan digunakan untuk menentukan halaju kebendaliran minimum. Tiga parameter yang diselidiki ialah sudut kecondongan, diameter zarah dan komposisi percampuran zarah. Keputusan yang didapati menunjukkan Umf berkurangan dengan penambahan sudut kecondongan. Pasir bersaiz kecil mempunyai Umf yang rendah. Tambahan lagi, percampuran pasiran yang mempunyai nisbah zarah bersaiz kecil yang tinggi menunjukkan Umf yang rendah. Oleh itu, kesan sudut kecondongan dan nisbah zarah bersaiz kecil dalam satu campuran pasiran terhadap Umf menunjukkan hubungan berkadar songsang, manakala kesan saiz zarah memberikan hubungan berkadar linear terhadap Umf.

Kata kunci: lapisan terbendalir; condong; halaju kebendaliran minimum

Fluidisation phenomena in an inclined fluidised bed (IFB) systems are poorly understood and receive less attention as compared to that of vertical fluidised bed although in practice there are many fluidised bed systems not vertically oriented. The objective of this work is to investigate the effect of inclination angle, particle size and particle composition to the minimum fluidisation velocity (Umf). The experiments were conducted in a rectangular IFB of dimension,7 cm x 50 cm a 2 mm thick metal distributor plate with 1 mm holes diameter (2.98 % opening area), water manometer, flow meter and compressor for fluidising air supply. The gradual decreasing velocity method was used to investigate the Umf. Three operating parameters were observed, namely angle of inclination, particle diameters and the compositions of mixed particles. The experimental results showed that the Umf of the particles is lower at higher angle of inclinations. The smaller particles have a lower Umf. The mixed sand with higher smaller particles mass fraction also has a lower Umf. Therefore, the effects of inclination angle and smaller particles mass fractions in the mixed sand to the Umf were observed to follow an inverse function, while, the particle size is linearly related to the Umf.

Key words: fluidised bed; inclicned; minimum fluidisation velocity
Analisis Kumpulan Hidroksil Permukaan dan Tapak Asid Zeolit Beta daripada Abu Sekam Padi dengan Kaedah Spektroskopi FTIR
Authors: Prasetyoko Didik , Endud Salasiah , Ramli Zainab
Published: January 2013

Analisis permukaan ke atas kumpulan hidroksil dan keasidan zeolit adalah penting dalam menentukan keberkesanan zeolit sebagai mangkin heterogen yang baik. Kajian jenis kumpulan hidroksil dan sifat keasidan telah dijalankan ke atas zeolit beta (BEA) yang disintesis daripada abu sekam padi berhablur secara terus pada nisbah SiO2/Al2O3 antara 20 - 90 bagi campuran gel pada suhu 150Â°C. Penentuan kumpulan hidroksil dan keasidan diamati dengan menggunakan kaedah spektroskopi FTIR dan penjerapan piridina sebagai molekul pengesan sifat asid. Keputusan menunjukkan hasil sintesis yang dikalsinkan pada suhu 400Â°C untuk penguraian templat organik menyebabkan pembentukan kumpulan hidroksil bagi silanol terminal dan tapak cacat (3740 cm-1), aluminium luar kerangka (3689 cm-1), dan aluminium kerangka (3608 cm-1). Semakin tinggi nisbah SiO2/Al2O3 sampel, semakin bertambah nisbah kumpulan silanol berbanding hidroksil aluminium kerangka. Regangan hidroksil yang terikat pada aluminium kerangka beranjak kepada frekuensi yang lebih rendah dengan pertambahan nisbah SiO2/Al2O3 gel. Semua sampel menunjukkan kehadiran kedua-dua tapak asid BrÂ¿nsted dan Lewis, dengan jumlah asid BrÂ¿nsted berkurang dengan pertambahan nisbah SiO2/Al2O3.

Kata kunci: zeolit; abu sekam padi; kumpulan hidroksil; keasidan; penjerapan piridina

Surface analysis on the hydroxyl groups and their acid characteristic is important in order to determine the effectiveness of zeolites as catalyst. Study on the types of hydroxyl groups and acidity was carried out on zeolite beta (BEA), synthesized directly from crystalline rice husk ash at gel SiO2/Al2O3 ratio between 20 - 90 and 150Â°C. FTIR spectroscopy - pyridine adsorption combined was used in the determination of hydroxyl groups and their acidity. Synthesised product calcined at 400Â°C for organic template decomposition resulted in the creation of hydroxyl of the type terminal silanol and defect hydroxyl (3740 cm-1), non-framework aluminium (3689 cm-1), and framework aluminium (3608 cm-1). As the SiO2/Al2O3 ratio increased, the ratio of silanol to framework aluminium increased. Hydroxyl stretching of the hydroxyl group attached to framework aluminium shifted to lower frequency with the increasing of SiO2/Al2O3 gel. All samples exhibit both BrÂ¿nsted and Lewis acidic sites with decreasing amount of BrÂ¿nsted acid as the SiO2/Al2O3 ratio increases.

Key words: zeolite; rice husk ash; hydroxyl group; acidity; pyridina adsorption
Occurrence and Morphological Description of Seagrasses from Pulau Redang, Terengganu, Malaysia
Authors: Zakaria Muta Harah , Bujang Japar Sidik , Abdul Razak Fazrullah Rizally
Published: January 2013

Tinjauan kehadiran rumput laut di kepulauan Pulau Redang telah dijalankan dari April 1996 hingga September 1998. Rumput laut telah dijumpai di empat kawasan; Cagar Hutang, muara Sungai Redang, Pasir Panjang dan Teluk Dalam. Tiga spesies; Halophila decipiens Ostenfeld, Halophilaminor (Zoll.) den Hartog dan Halodule pinifolia (Miki) den Hartog telah direkodkan di perairan Pulau Redang. Kesemua spesies tumbuh subur di kawasan sub-tidal: kelompok monospesifik H. pinifolia tumbuh di atas substrat berpasir pada kedalaman 2.5â€“5.0 m di Pasir Panjang dan Teluk Dalam, dan populasi H. minor di atas substrat yang sama pada kedalaman 6 m di muara Sungai Redang. Hamparan H. decipiens tumbuh di atas substrat berlumpur dijumpai di muara Sungai Redang (kedalaman 6 m) dan Cagar Hutang (kedalaman 24 m). Perbezaan morfologi dalam H. decipiens dapat dikesan dan ini disebabkan kedalaman dimana spesies ini didapati. Keterangan dan perbincangan tentang morfologi keseluruhan dan pembiakan disertakan.

Kata kunci: diversity (kepelbagaian); rumput laut; ekologi; morfologi; Pulau Redang

The occurrence of seagrasses was surveyed around the Pulau Redang water from April 1996 to September 1998. Seagrasses were observed at four locations; Cagar Hutang, Sungai Redang estuary, Pasir Panjang and Teluk Dalam. Three species; Halophila decipiens Ostenfeld, Halophilaminor (Zoll.) den Hartog and Halodule pinifolia (Miki) den Hartog were recorded around Pulau Redang. All species were thriving in the sub-tidal areas; monospecific patches of H. pinifolia grew on sandy substratum at depth of 2.5â€“5.0 m at Pasir Panjang and Teluk Dalam, and a population of H. minor on similar substrate at depth of 6 m at Sungai Redang estuary. Meadows of H. decipiens on silty substratum were observed at Sungai Redang estuary (depth 6 m) and Cagar Hutang (depth 24 m). Morphological plasticity due to varied depth distribution was detected in the seagrass, H. decipiens. The descriptions on general and reproductive morphologies are given.

Key words: diversity; seagrass; ecology; morphology; Pulau Redang
Diagnostic of Preliminary Breakdown in an Artificial Thunderclouds
Authors: Bidin Noriah , Madia Pangeran
Published: January 2013

Kilat ialah satu fenomena kemusnahan. Kilat boleh menyebabkan kebakaran, kerosakan dan membunuh manusia dan haiwan. Oleh itu, kita perlu mempunyai sejenis alat pencegahan untuk memicu kilat sebelum ia boleh menyambar secara semula jadi. Salah satu kaedah yang boleh digunakan ialah dengan menggunakan laser. Dalam kajian ini satu laser UV digunakan untuk mengaktifkan penyahcasan cas elektrik. Elektrod dianggap sebagai awan petir. Jarak pisah antara elektrod dilaraskan untuk menentukan kewujudan permulaan runtuhan. Keputusan menunjukkan, permulaan runtuhan berlaku pada jarak yang pendek. Ini bermakna medan elektrik yang tinggi diperlukan. Runtuhan terangsang apabila diganggu oleh laser UV dalam awan petir. Dalam situasi ini, jarak pisah didapati mencapai tiga kali ganda berbanding jarak tanpa laser. Oleh itu medan elektrik yang minimum diperlukan untuk kejadian permulaan runtuhan seperti itu.

Kata kunci: Runtuhan; kilat; medan elektrik; percikan api elektrik; voltan tinggi; laser

Lightning is a destructive phenomenon. It can cause fire, damage and electrocute human being and animal. Therefore, we need to have some kinds of protective devices to trigger lightning before it could strike naturally. One way of doing it is by using laser. In this study unfocused UV laser was used to actively discharge the electrodes. Electrodes are used to represent thunderclouds. The separation distance between the electrodes was adjusted to determine the condition for preliminary breakdown. The result showed that, preliminary breakdown occurred at a short ranges separation distance of electrodes, hence very high electric field is required. The breakdown is found stimulated by interfering a UV laser in the thunderclouds. In this respect, the separation distance for breakdown is triple that of without laser. Hence minimum electric field can be achieved for such occurrence of preliminary breakdown.

Key words: Breakdown; lightning; electric field; electrical spark; high voltage; laser
Separation of Organophosphorus Pesticides Using Micellar Electrokinetic Chromatography
Authors: W. Ibrahim W. Aini , Monjurul Alam S. M. , Sulaiman Azli
Published: January 2013

Pemisahan enam pestisid organofosforus (mevinfos, metidation, diazinon, prefenofos, kuinalfos dan klorpirifos) telah dikaji menggunakan teknik kromatografi elektrokinetik misel (MEKC) dengan pengesan Ultralembayung–Nampak. Proses pemisahan dilakukan dengan menggunakan surfaktan anionik natrium dodesil sulfat (SDS) dan larutan penimbal borat atau fosfat sebagai elektrolit pembawa. Pemisahan yang dilakukan didapati tidak lengkap walaupun telah dilakukan perubahan terhadap pelbagai faktor seperti jenis larutan penimbal, kepekatan surfaktan dan larutan penimbal, penambahan pengubahsuai metanol dan juga pengubahsuaian pH larutan penimbal yang digunakan. Tanpa penggunaan dan pengubahsuaian faktor di atas, pestisid mevinfos sahaja selalu muncul sebagai puncak yang tajam diikuti oleh diazinon dan metidation. Walaupun tanpa kehadiran surfaktan SDS dalam matrik larutan penimbal, mevinfos dan diazinon dapat dikesan manakala pestisid OPPs yang lainnya tidak dapat dikesan. Penggunaan β–siklodekstrin (β–CD) 6 mM, penimbal borat 20 mM dengan SDS 40 mM dan pH penimbal 9.5 memberikan keputusan terbaik bagi pemisahan pestisid mevinfos, diazinon dan metidation. Keputusan dalam kajian ini mencerminkan kaitan antara keterlarutan dan sifat hidrofobik pestisid.

Kata kunci: Pestisid organofosforus; kromatografi elektrokinetik misel; natrium dodesil sulfat; siklodekstrin; ultralembayung-Nampak

Separation of six organophosphorus pesticides (mevinphos, methidathion, diazinon, profenofos, quinalphos and chlorpyrifos) has been investigated using micellar electrokinetic chromatography (MEKC) with on–column UV–Vis detection. Separations involved using anionic sodium dodecyl sulphate (SDS) surfactant and phosphate or borate buffer as carrier electrolytes. Separations have been found incomplete regardless of changing all sort of possible factors such as buffer types, buffer and surfactant concentrations, addition of organic modifier, methanol and pH of the running buffer. Irrespective of the combinations of levels of factors, mevinphos alone appeared always as a distinguishable strong peak followed by diazinon and methidathion. Even in the absence of any surfactant in buffer matrices, mevinphos and diazinon were detected but methidathion, profenofos, quinalphos and chlorpyrifos were undetected. The use of 6 mM β–cyclodextrin (β–CD), 20 mM borate buffer with 40 mM SDS and buffer pH of 9.5 resulted in the best separation of mevinphos, diazinon and methidathion. The results found in this study might reflect the solubility and hydrophobicity properties of the pesticides.

Key words: Organophosphorus Pesticides (OPPs); Micellar electrokinetic chromatography; Sodium dodecy sulphate; cyclodextrin; UV-Vis
A Potential Use Of Dehalogenase D (DEHD) From Rhizobium sp. For Industrial Process
Authors: Huyop Fahrul Z. , A. Cooper Ronald
Published: January 2013

DehL dan DehD dari Rhizobium sp. yang di hasilkan secara pengekspresan gen di dalam E.coli telah ditulenkan menggunakan kolum pertukaran ion kromatografi. Pencirian telah dilakukan terhadap DehL dan DehD melalui analisis kinetik untuk menentuan nilai pemalar Km, Kcat dan pemalar tetap. Analisis kinetik menunjukkan DehD dari Rhizobium sp. mempunyai nilai Km yang lebih rendah (0.04mM dengan D,L-2-CP) dan nilai Kcat (6.28saat–1 bagi D,L-2-CP) dan pemalar tetap (1.46 105 M–1sec–1 bagi D,L-2-CP) yang lebih tinggi berbanding dengan dehalogenase D-spesifik dari pada organisma lain menunjukkan DehD dari Rhizobium sp. merupakan pemangkin yang lebih baik. D-2-haloasid amat penting dalam industri bio-pemangkin berbanding dengan L-2-haloasid, dan data kinetik DehD menjanjikan ia boleh diguna dalam proses industri sekiranya dimajukan.

The Rhizobium sp. DehL and DehD were produced by heterologous expression of the cloned gene in E.coli and both proteins purified using anion-exchange column chromatography. DehL and DehD were characterised by kinetic analysis to determine their Km, Kcat and the Specificity constant values. The kinetic analysis results showed that DehD from Rhizobium sp. has lower Km value (0.04 mM with D,L-2-CP) and higher Kcat (6.28 sec–1 for D,L-2-CP) and Specificity constants (1.46 105 M–1sec–1 for D,L-2-CP) compared to other D-specific dehalogenases from different organism suggesting DehD enzyme from Rhizobium sp. is better catalysts. D-2-haloacid dehalogenase is important for industrial biocatalysis compared to the L-2-haloacid and the kinetic data of DehD hold promise for further development to be used in an industrial process.
Extraction of Junctions, Lines and Regions of Irregular Line Drawing: The Chain Code Processing Algorithm
Authors: Haron Habibollah , Mohamed Dzulkifli , Hj. Shamsuddin Siti Mariyam
Published: January 2013

Peringkat konsepsualisasi dalam kitar hayat reka bentuk produk kejuruteraan merupakan proses menterjemahkan idea jurutera ke atas sehelai kertas. Menggunakan sebatang pensil dan sehelai kertas, bentuk produk yang diinginkan akan dilakar. Lakaran seterusnya akan dikemaskinikan dengan menambah dimensi yang lebih tepat beserta pandangan-pandangan tambahan bagi menunjukkan kawasan terlindung. Kertas kerja ini membincangkan proses-proses yang terlibat dalam menterjemahkan lakaran berupa lukisan garisan tak sekata kepada lukisan sekata yang kemas. Proses ini juga turut menghasilkan tiga entiti penting iaitu simpang, garisan dan kawasan. Algoritma kod rantaian digunakan bagi mendapatkan entiti ini. Kertas kerja ini juga menerangkan proses penipisan yang terlibat sebelum algoritma kod rantaian dilaksanakan. Andaian-andaian, beberapa definisi penting dan kaedah memindahturun fail imej juga dipersembahkan. Kertas kerja ini diakhiri dengan beberapa lakaran input, kesimpulan dan cadangan pembaikan.

Kata kunci: Terjemahan lukisan garisan; kod rantaian; pengestrakkan ciri; algoritma penipisan

Conceptualization stage in designing engineering product is a process of translating engineer´s idea onto a sheet of paper. The product is always sketched on a sheet of paper using pencil. The sketch is tidied up by adding accurate dimension, and complete view of hidden part. This paper discusses part of the process involved in translating the sketch or irregular line drawing into a tidy or regular line drawing, that yield three important entities namely junction, line and region. The chain code algorithm is used to find these entities. The paper also explains explicit thinning process involved before the chain code methodology. Assumptions, important definitions and method of loading image file are also presented. The paper is concluded with several test input sketches, conclusion and future works.

Key words: Line drawing; interpretation; chain code; feature extraction; thinning algorithm
Matrix Acidizing with Gelled Acid
Authors: Ismail Issham , Kweh Wei Loon
Published: January 2013

Suatu uji kaji makmal telah dilakukan untuk membandingkan kecekapan asid gel dan asid lumpur konvensional dalam merawat kerosakan formasi yang disebabkan oleh lumpur dasar air. Suatu sistem pengasidan telah dibina untuk mengkaji kesan kadar alir dan kelikatan asid gel terhadap batu pasir Berea. Peralatan utama yang membentuk sistem pengasidan ialah pemegang teras, sel lumpur, injap, dan tiub 3 mm. Semua komponen ini diperbuat daripada keluli kalis karat. Bendalir perawat yang digunakan dalam uji kaji terdiri daripada asid lumpur (3% HF–12% HCl), asid hidroklorik, dan gel polimer (gam xanthan). Keputusan uji kaji menunjukkan bahawa polimer dengan kelikatan kurang daripada 73 cP memberikan kecekapan yang lebih baik berbanding kelikatan yang melebihi 73 cP. Ini terbukti apabila nisbah kebolehtelapan mencapai 3.5 pada kelikatan gel 73 cP berbanding 1.5 sahaja pada kelikatan 126 cP. Perbezaan nisbah kebolehtelapan yang ketara berlaku kerana polimer yang terlalu likat cenderung untuk memalam liang secara kekal. Asid gel berjaya merawat kerosakan formasi dengan lebih berkesan berbanding asid lumpur, terutama apabila gel polimer berkelikatan 73 cP dialirkan pada kadar alir 0.28 ml/saat, berbanding kadar alir yang lebih rendah.

Kata kunci: Teknik lencongan; asid gel; pengasidan; gel polimer

A laboratory investigation was conducted to compare the efficiency of gelled acid with conventional/plain mud acid in removing the formation damage induced by water-based mud. An acidizing system was developed to study the effect of flow/injection rate and gel viscosity on Berea sandstone. The main equipments used in this research study were stainless steel core holder, mud cells, valves, and 3 mm tubing. The treatment fluids used were mud acid (3% HF–12% HCl), hydrochloric acid, and polymer gel (xanthan gum). The experimental results revealed that polymer gel with viscosity lower than 73 cP gave better performance as compared to polymer gel with viscosity greater than 73 cP. At gel viscosity of 73 cP, the permeability ratio was 3.5 compared to 1.5 only at viscosity of 126 cP. This was due to the permanent plugging by the high viscosity polymer gel in the core after the injection. Gelled acid has shown tremendous improvement in removing formation damage, where polymer gel with viscosity of 73 cP was found to give better treatment at flow rate of 0.28 ml/s as compared to lower flow rates.

Key words: Diversion technique; galled acid; acidizing; polymer gel
Tin-Tannin-Lignosulfonate Complex: An Improved Lignosulfonate-Based Drilling Fluid Thinner
Authors: Mohamad Ibrahim M. N. , Chuah S. B. , P. Y. Cheng
Published: January 2013

Satu penipis lumpur gerudi yang diperbaiki iaitu kompleks stanum–tanin–lignosulfonat, telah dihasilkan dengan melakukan pengubahsuaian terhadap penipis komersil iaitu lignosulfonat. Tindak balas yang terlibat termasuk tindak balas rangkai silang antara asid lignosulfonat dengan tanin pada suhu 105°C dengan kehadiran formaldehid yang berfungsi sebagai pemula tindak balas tersebut. Campuran tersebut selanjutnya dikelatkan dengan ion stanum. Tindak balas pengubahsuaian tersebut ditentusahkan menerusi analisis spektroskopi inframerah (IR) dan prestasinya sebagai agen penipis berpolimer bagi lumpur bentonit akueus dinilai. Prestasi reologi penipis terubahsuai tersebut kemudiannya dibandingkan dengan lignosulfonat. Keputusan menunjukkan bahawa penipis terubahsuai mempunyai prestasi penipisan yang lebih baik berbanding lignosulfonat pada suhu tinggi dan juga ketahanan yang lebih tinggi terhadap pencemaran garam.

Kata kunci: lignosulfonat; bendalir/lumpur gerudi;ion stanum; tannin; prestasi reologi

An improved drilling fluid thinner, tin–tannin–lignosulfonate (TTLS) complex; was formulated by imposing slight modifications to a commercially available thinner, lignosulfonate. The reactions involved include reaction of a lignosulfonate acid with tannin at 105°C in the presence of formaldehyde to initiate the cross-linking reaction. The mixture was further chelating with stannous ions. The modifications reactions were verified by an infrared (IR) spectroscopy analysis and its performances as a polymeric thinning agent for aqueous bentonite mud were evaluated. The rheological performances of the modified thinner were then compared with lignosulfonate. The modified thinner shows better thinning performance at higher temperature and indicates more tolerance to salt contamination compared to lignosulfonate.

Key words: lignosulfonate; drilling fluid/mud; thinner; stannousion; tannin; rheological perfomances
Removal of Residual Oil from Palm Oil Mill Effluent Using Solvent Extraction Method
Authors: H. Hameed Bassim , Ahmad Abdul Latif , Ng. Ai Hoon
Published: January 2013

Pencemaran akibat dari minyak buangan yang terkandung dalam air sisa merupakan salah satu masalah persekitaran yang amat serius. Disebabkan oleh perkembangan industri kelapa sawit yang amat pesat di Malaysia, suatu isipadu air sisa dari kilang kelapa sawit (POME) yang banyak juga dihasilkan pada masa yang sama. Pengekstrakkan minyak buangan dari POME telah dijalankan menggunakan proses pengektrakan pelarut. Dalam kajian ini, kesan masa pengektrakan, nisbah pelarut/suapan dan kadar pencampuran pengektrakan menggunakan beberapa jenis pelarut telah dijalankan. N–pentana, n–hexana dan n–heptana telah digunakan sebagai pelarut. Peratus minyak yang diekstrakkan pada keadaan–keadaan optimum ujikaji menggunakan n–pentana, n–hexana dan n–heptana diperolehi masing–masing sebanyak 58, 63 dan 65 peratus. Pengekstrakan berbagai peringkat juga telah dijalankan. Lebih dari 97% minyak buangan yang terkandung dalam POME telah berjaya diekstrakkan pada peringkat keempat pengekstrakkan menggunakan pelarut–pelarut tersebut.

Kata kunci: Pengekstrakkan; kadar pencampuran; masa pencampuran; pelarut; POME

Pollution from residual oil content in the wastewater is one of the serious environmental problems. Due to the rapid development of the palm oil industry in Malaysia, a large volume of palm oil mill effluent (POME) has been produced at the same time. Removal of residual oil from POME was carried out using solvent extraction process. The effect of different solvents, extraction time, solvent/feed ratio and mixing rate on extraction efficiency were investigated throughout this work. N– pentane, n–hexane and n–heptane were used as solvents. The percent of oil extracted at the optimum conditions of 10 min extraction time, 1:1 solvent: feed ratio, 200 rpm using n–pentane, n–hexane and n–heptane were found to be 58, 63 and 65, respectively for a single stage extraction. Multistage extraction has shown that the % of oil extracted increased significantly to more than 97% of the residual oil in the POME.

Key words: Extraction; mixing rate; mixing time; solvent; POME
Development of Neural Network Models for a Crude Oil Distillation Column
Authors: Mohd. Yusof Khairiyah , Karray Fakhri , Douglas Peter L.
Published: January 2013

This paper discusses the development of artificial neural network (ANN) models for a crude oil distillation column. Since the model is developed for real time optimisation (RTO) applications they are steady state, multivariable models. Training and testing data used to develop the models were generated from a reconciled steady-state model simulated in a process simulator. The radial basis function networks (RBFN), a type of feedforward ANN model, were able to model the crude tower very well, with the root mean square error for the prediction of each variable less than 1%. Grouping related output variables in a network model was found to give better predictions than lumping all the variables in a single model; this also allowed the overall complex, multivariable model to be simplified into smaller models that are more manageable. In addition, the RBFN models were also able to satisfactorily perform range and dimensional extrapolation, which is necessary for models that are used in RTO.
Kepuasan Pengguna Selepas Pengiktirafan ISO 9001: Kajian Kes Sebuah Fakulti di Universti Teknologi Malaysia
Authors: Baharun Rohaizat
Published: January 2013

Kepuasan pengguna merupakan isu yang paling kerap dibincangkan dalam semua organisasi sama ada sektor awam mahupun swasta. Para pelajar intitusi pengajian tinggi merupakan pengguna dalaman kepada servis dan produk yang ditawarkan kepada mereka; lebih-lebih lagi kepada institut yang telah diiktiraf dan mendapat persijilan ISO 9000. Dengan menggunakan pengubahsuaian pengukuran SERVPERF dan SERVQUAL dalam kajian literatur, satu kajian telah dibuat untuk mengukur tahap dan pengaruh kepuasan pengguna kepada Fakulti Pengurusan dan Pembangunan Sumber Manusia, Universiti Teknologi Malaysia, Skudai, Johor. Hasil dari kajian menunjukkan bahawa kepuasan pengguna bertambah apabila mereka melihat perubahaan yang signifikan dari segi penawaran servis dan produk yang dilakukan selepas fakulti mendapat sijil ISO 9000.

Kata kunci: ISO 9000; Kualiti; Kepuasan Pengguna; Institut Pengajian Tinggi; Pemasaran Servis

Customer satisfaction is perhaps one of the most talked about challenges of organizations, both in private and public sectors. In tertiary institutions, students can be categorized as customers they use the services and products provided, especially the institutes which have been awarded the ISO 9000 certification. By using the modified SERVPERF and SERVQUAL instrument as suggested in the literature review, a survey was conducted to measure the level and to explain customer satisfaction at the Faculty of Management and Human Resource Development, University Technology Malaysia, Skudai, Johor. The findings show that customer satisfaction increases significantly in relation to the output/outcomes from the implementation of quality service and product after the faculty was awarded the ISO 9000 certificate.

Key words: ISO 9000; Quality; Customer satisfaction; Institutions of Higher Learning; Service marketing
Peristiwa Tahkim Antara ‘Ali dan Mu´awiyah (Tahun 36 H): Suatu Kajian dan Pengajaran
Authors: Marni Nurazmallail
Published: January 2013

Tulisan ini membincangkan Peristiwa Tahkim iaitu persetujuan antara Saidina cAli dan Mu‘ã–wiyah pada tahun 36 H untuk menerima keputusan wakil–wakil yang dilantik dalam menyelesaikan perselisihan antara mereka. Objektif kajian ini ialah untuk memberikan penjelasan menangani peristiwa tersebut. Kajian ini meliputi perbincangan dari beberapa aspek seperti faktor pendorong Peristiwa Tahkim, gambaran peristiwa pada peringkat permulaan dan peringkat perhimpunan wakil kedua pihak. Kajian ini juga membuat analisis terhadap faktor–faktor kegagalan Saidina cAli menangani isu Tahkim dan justifikasi pendirian beberapa sahabat mengenai perlantikan ‘Ali sebagai khalifah. Fokus utama kajian tertumpu pada sejauhmana kebenaran cerita yang mengatakan bahawa wakil pihak Mucãwiyah iaitu cAmr ibn Al–cÃs telah memperdayakan wakil pihak Saidina cAli iaitu Abu Musã al–Ashcari hingga berjaya melucutkan jawatan khalifah daripada Saidina cAli dan mengekalkan kedudukan Mucãwiyah. Kajian mendapati pendapat yang menerima cerita penipuan cAmr ibn Al–cÃs dalam majlis Tahkim lebih berdasarkan sumber riwayat, sementara pendapat yang menolak kesahihannya adalah berdasarkan hujah akal yang disokong oleh beberapa riwayat yang menjelaskan realiti sebenar peristiwa. Ini bermakna pandangan yang mengatakan bahawa Abu Musa al–Ashcari adalah seorang yang bodoh sementara cAmr ibn Al–cÃs adalah seorang penipu, kurang pegangan agama dan tidak menepati janji merupakan pandangan yang salah dan perlu dijauhi.

Kata kunci: Peristiwa TAhkim; Saidina Ali; Muawiyah; Amr ibn Al-As; Abu Musa al-Ashari

This article focusses on the event of tahkim; an agreement between Caliph cAli and Muawiyah to enable their representatives discuss and find solution for their dispute. A thorough explanation is important in order to clear untruthful narration that surrounded the event. The discussion will include factors that led to the event; the developments of the event, and the meeting itself. This research will also focus on the factors which led to Caliph cAli´s failure in the tahkim as well as justifications of the companions on the appointment of cAli as caliph. The main focus will be on whether cAmr ibn Al–cÃs manipulated and cheated cAli´s representative Abu Musa al–Ashcari loosing cAli which led to his position as the caliph to Muawiyah. This research suggests that the current perceptions of Muslims on the issues are baseless and should be avoided.

Key words: Event of Tahkim; Caliph Ali Muawiyah; Amr ibn Al- As; Abu Musa al-Ashari
Mechanical and Morphological Study of Talc/calcium Carbonate Filled Polypropylene Hybrid Composites Weathered in Tropical Climates
Authors: Leong Y. W. , Abu Bakar M. B. , Mohd. Ishak Z. A. , Ariffin A.
Published: January 2013

Dua jenis komposit, iaitu komposit polipropilena (PP) terisiâ€“tunggal (diisi dengan talkum atau kalsium karbonat) dan komposit PP terisiâ€“hibrid (diisi campuran talkum dan kalsium karbonat) yang telah diacuanâ€“suntikkan kepada bentuk â€˜dumbbellâ€™. Spesimen tersebut didedahkan kepada pencuacaan semulajadi, iaitu iklim tropika di Pulau Pinang, Malaysia selama 6 bulan. Selepas tempoh pendedahan, sifat mekanikal PP terisiâ€“tunggal telah merosot akibat degradasi fizikal dan kimia yang teruk. Kajian yang lebih mendalam ke atas aspek struktur komposit telah dijalankan untuk mendapatkan kepastian tentang keadaan degradasi tersebut. Walau bagaimanapun, komposit PPâ€“terisi hibrid menunjukkan keupayaan untuk mengekalkan sifat tegangan dan lenturan yang lebih baik walaupun terdapat kesan degradasi pada permukaan spesimen. Didapati bahawa kesan â€˜hibridisasiâ€™ telah berjaya meningkatkan ketahanan komposit hibrid terhadap degradasi pencuacaan yang teruk, sehingga strukturâ€“struktur di dalam komposit tersebut dapat dilindungi daripada kesan degradasi, sedangkan permukaan komposit telah mengalami degradasi yang teruk.

Kata kunci: Polipropilena; komposit hibrid; pengoksidaan foto; pengguntingan rantai; degradasi terma; pencuacaan semula jadi

Two kinds of composites, namely singleâ€“filler polypropylene (PP) composites (contain either talc or calcium carbonate) and hybridâ€“filler PP composites (consist of a mixture of talc and calcium carbonate) were injection moulded into dumbbells. These specimens were subjected to natural weathering i.e. tropical climate in Penang, Malaysia for 6 months. After 6 months of exposure, the mechanical properties of singleâ€“filler PP composites deteriorated due to severe physical and chemical degradation. This was confirmed after studies were made on the structure aspects of the composite. However, the hybridâ€“filler PP composites were found to show better retention in both tensile and flexural strength albeit have undergone some degree of degradation as well. It was found that the â€˜hybridizationâ€™ effect has successfully increased the resistance of the hybrid composite to severe environmental degradation to the extent that it protects the internal structure of the composite from environmental damage, while the surface of the composite gets severely degraded.

Key words: Polypropylene; hybrid composite; photooxidation; chain scission; thermal degradation; natural weathering
Intelligent Object Analyser for Conceptual Database Design Model
Authors: Mohd. Noah Shahrul Azman , Williams Michael
Published: January 2013

Fasa reka bentuk konseptual pangkalan data merupakan fasa terpenting dalam proses pembangunan sebuah sistem pangkalan data memandangkan model konseptual yang terhasil melalui fasa ini adalah merupakan model semantik pertama yang dijanakan. Walau bagaimanapun, fasa ini juga digambarkan sebagai suatu fasa yang sukar dan kemungkinan untuk berlaku ralat pemodelan adalah tinggi. Sehubungan dengan itu, beberapa sistem pengautomasian yang berasaskan teknik kecerdasan buatan telah dibangunkan yang bertujuan untuk membantu mereka bentuk model konseptual tersebut. Tetapi kebanyakan daripada sistem ini lebih tertumpu kepada aspek sintesis reka bentuk dengan kemampuan diagnosis yang sangat terhad. Melalui kertas ini, satu set petua diagnosis telah dicadangkan dan diimplementasikan di dalam prototaip sistem iaitu Intelligent Object Analyser (IOA). Sungguhpun pengujian awal telah menunjukkan keputusan yang menggalakkan, masih lagi terdapat ralat pemodelan yang gagal dikesan oleh petua diagnosis yang dicadangkan. Kertas ini diakhiri dengan perbincangan dan perluasan penyelidikan dalam bidang ini.

Kata kunci: Model konseptual, reka bentuk pangkalan data, sistem kecerdasan, sistem berasaskan pengetahuan

Conceptual database design is seen as the most important stage of a database design process, as the conceptual model produced at this stage is the first design model constructed with formal and detailed semantics. The stage, however, is also viewed as a difficult task for designers, and the potential for committing and correcting errors is significant. As a result, it is not surprising to see the emergence of a number of automated systems employing artificial intelligence (AI) techniques in providing assistance in the design of such a model. However, the majority of these tools have been focussed on the task of design synthesis with limited diagnostic capabilities. This paper, therefore, proposed a set of diagnostic rules meant for intelligent diagnosis of conceptual database design model. These rules have been implemented using a prototype tool called the Intelligent Object Analyser (IOA). Initial testing on a number of domains has so far produce encouraging results. However, there still remains undiagnosed cases whereby the proposed diagnostic rules incapable of diagnosing. The paper concludes with a discussion of areas for future development in this field.

Key words: Conceptual modelling, database design, intelligent system, knowledge-based system
Mengkaji Keberkesanan Aplikasi Pemusar Udara Ram Bilah Rata dalam Mengurangkan Emisi dari Pembakar Berbahan Api Cecair
Authors: Mohd Jaafar Mohammad Nazri , Samat Ismail , Abdul Mookmin Muhamed Shukri
Published: January 2013

Enjin turbin gas digunakan secara meluas sama ada dalam bidang industri atau penerbangan. Kecekapan enjin merupakan salah satu kriteria dalam pemilihan enjin yang baik. Pembakar adalah antara komponen penting dalam enjin turbin gas yang banyak diberi perhatian dalam kajian oleh penyelidik. Pembakar yang baik dapat menghasilkan pembakaran yang sempurna dengan kadar bahan cemar yang minimum. Ini dapat dicapai dengan menggunakan pemusar udara. Maka melalui projek ini, kajian dilakukan untuk mengkaji keberkesanan aplikasi pemusar udara ram rata dalam mengurangkan emisi dari pembakar berbahan api cecair. Ujian pembakaran yang dilakukan menggunakan pemusar udara aliran jejarian ram rata dengan sudut pesongan ram yang berlainan. Tahap penghasilan bahan cemar diukur dan dibandingkan bagi sudut–sudut bilah yang berlainan. Keputusan yang diperolehi menunjukkan sudut pesongan bilah yang tertinggi memberikan tahap pengeluaran bahan cemar terendah berbanding sudut–sudut bilah yang lain.

Kata kunci: Pemusar udara, NO, CO, bahan api cecair, ram bilah rata

Gas turbine engine has been used extensively either in the industrial or the aviation sector. Engine efficiency is one of the criteria in selecting a good engine. The combustor or combustion chamber is one of the important components in a gas turbine engine that has been given attention by researchers in their research. A good combustor is capable to achieve complete combustion with minimal pollutants emissions. This can be achieved by the application of air swirler. Through this work, a study has been made to demonstrate the effectiveness of the application of straight vane air swirler in reducing emissions from liquid fuel combustor. Tests were done using straight blade radial air swirler with varying vane angles. Emissions level emitted from the combustor was measured and compared for varying vane angles. Results obtained show that the highest vane angle produces the lowest level of emissions compared to the other vane angles.

Key words: Air swirler, NO, CO, liquid fuel, straight vane
Tahap Penghayatan Nilai-Nilai Murni di Kalangan Pelajar-Pelajar Sarjana Muda Teknologi serta Pendidikan Semasa Menjalankan Kerja Amali Bengkel
Authors: Buntat Yahya , Sanapi Rozita
Published: January 2013

Kajian yang dijalankan ini adalah bertujuan untuk meninjau tahap penghayatan nilai–nilai murni para pelajar Sarjana Muda Teknologi Serta Pendidikan (Kemahiran Hidup) di Universiti Teknologi Malaysia semasa menjalani kerja amali di bengkel. Kajian ini melibatkan sejumlah 92 sampel kajian yang terdiri daripada pelajar–pelajar tahun satu dan tahun tiga Sarjana Muda Teknologi Serta Pendidikan (Kemahiran Hidup) 1997/1998. Maklumat kajian diperolehi melalui soal selidik yang diedarkan kepada semua sampel yang terlibat. Hasil kajian mendapati para pelajar tersebut mempunyai tahap penghayatan yang tinggi dan bersikap positif. Bagaimanapun, beberapa aspek nilai–nilai murni didapati mendapat peratus penghayatan yang rendah dan perlu diberi perhatian semasa proses pembelajaran dijalankan. Beberapa cadangan telah dikemukakan bagi memantapkan lagi amalan penghayatan nilai-nilai murni yang telah dilaksanakan.
Thermoacoustic Heat Engine
Authors: Mohd. Ghazali N. , Nasir Ani Farid
Published: January 2013

Kertas kerja ini memperkenalkan teknologi terbaru dalam kuasa bendalir iaitu termoakustik, fenomenon yang disebabkan oleh interaksi pepejal-bendalir. Secara umumnya, termoakustik boleh dibahagi kepada dua kategori. Kategori pertama ialah enjin haba, di mana kuasa akustik dapat dijana hasil daripada gelombang yang wujud disebabkan oleh perbezaan suhu yang merentas suatu susunan plat. Keadaan sebaliknya untuk pam haba, di mana pemindahan haba berlaku merentas suatu susunan plat dengan kuasa akustik masukan dalam bentuk gelombang akustik. Teori asas termoakustik dan beberapa parameter reka bentuk sistem termoakustik yang diguna penyelidik masa kini dibincangkan disini. Analisis dengan menggunakan teori tersebut juga dilakukan. Perbincangan ini adalah sebagai dorongan untuk penyelidikan dalam bidang termoakustik khususnya secara eksperimen dan analisis berangka.

Kata kunci: Termoakustik, parameter reka bentuk, analisis

This paper is an attempt at introducing the latest technology in fluid power, thermoacoustics, a phenomenon due to solid-fluid interactions. Thermoacoustics can be generally characterised by the following two categories. The first, the oscillations induced by temperature difference across a stack of plates can generate acoustic power consistent of a prime mover. While the reverse, that of heat transfers across a stack of plates powered by acoustic waves is typical of a heat pump learnt in the engineering introductory course. Basic thermoacoustic theory and some simple thermoacoustic design parameters that are currently being used are discussed. Analysis using these theories is shown. Discussions through this paper will show the way for initial and continuing research into thermoacoustics, particularly in the experimental and numerical fields.

Key words: Thermoacoustics, design parameters, analysis
Gain and Noise Figure Performances of L–Band EDFA with an Injection of C–Band ASE
Authors: Wadi Harun Sulaiman , Subramaniam T. , Tamchek Nizam , Ahmad Harith
Published: January 2013

Kesan suntikan pancaran spontan terkuat (ASE) jalur–C terhadap prestasi jalur–L penguat gentian terdop–erbium (EDFA) ditunjukkan. Sebuah pekeliling dan parutan gentian Bragg lebar jalur luas digunakan untuk menyalurkan ASE jalur–C ke dalam sistem penguat. Dengan penyuntikan sejumlah kecil ASE (20 dB pelemahan dan lebih), gandaan isyarat kecil ditingkatkan tanpa peningkatan nilai hingar berbanding penguat tanpa suntikan ASE. Peningkatan gandaan maksimum adalah sebanyak 3.5 dB dan dicapai semasa pelemahan 20 dB untuk isyarat 1580 nm. Walau bagaimanapun, jika penguat disuntik dengan jumlah ASE yang besar (VOA=0 dB), gandaan penguat didapati mendatar pada 15.2 dB dari –40 hingga –10 dBm dengan variasi gandaan kurang daripada 0.3 dB. Kuasa tepu juga bertambah dari –8 dBm (semasa tiada ASE) kepada 2 dBm (VOA=0 dB) dengan sedikit peningkatan nilai hingar. Keputusan ini menunjukkan bahawa teknik menyuntik ASE boleh digunakan sama ada untuk meningkatkan gandaan atau untuk menetapkan nilai gandaan dalam EDFA jalur–L.

Kata kunci: Penetapan gandaan, penguat optik, EDFA jalur-L, penambahan gandaan, pancaran spontan terkuat

The effect of injecting conventional band amplified spontaneous emission (C–band ASE) on the performance of long wavelength band erbium–doped fiber amplifier (L–band EDFA) is demonstrated. A circulator and a broadband fiber Bragg grating (FBG) were used to route a C–band ASE into amplifier system. Injection of a small amount of ASE (attenuation of 20 dB and above) improves the small signal gain with a negligible noise figure penalty compared to that of an amplifier without the ASE injection. A maximum gain improvement of 3.5 dB is obtained at an attenuation of 20 dB for signal wavelength of 1580 nm. At very large amount of ASE injection (VOA=0 dB), the gain of the amplifier is clamped at 15.2 dB from –40 to –10 dBm with a gain variation of less than 0.3 dB. The saturation power is also increased from –8 dBm (for without ASE injection) to 2 dBm (VOA=0 dB) with a slight noise figure penalty. These results show that the ASE injection technique can be used either for gain improvement or gain clamping in L–band EDFA.

Keywords: Gain clamping, optical amplifier, L-band EDFA, gain enhancement, amplified spontaneous emission
Preliminary Investigation of Gray Coded M–Quadrature Amplitude Modulation in Orthogonal Frequency Division Multiplexing Over Additive White Gaussian Noise Channel
Authors: Noordin Nor K. , M. Ali Borhanuddin , Jamuar S. S. , A. Rahman Tharek , Ismail Mahamod B.
Published: January 2013

Dalam makalah ini, kami menyelidik prestasi M–Modulasi Amplitud Kuadratur terkod–Gray dalam sistem penghantaran menggunakan skema Multiplexan Pembahagian Frekuensi Ortogonal (OFDM) melalui saluran hingar Gaussian (AWGN). QAM terkod Gray dengan 1 bit ke 8 bit per simbol bersamaan dengan 2–QAM ke 256–QAM dijana dan dimasukkan ke dalam sistem penghantaran OFDM. Prestasi sistem dalam bentuk kadar ralat bit (BER) diberi berbanding saiz jelmaan Fourier pantas (FFT), bilangan sub-pembawa, panjang prefix-kitaran, dan toleransi terhadap nisbah isyarat kepada hingar (SNR) dalam saluran. Dapatan awal menunjukkan hanya modulasi 16–QAM ke bawah boleh diterimapakai untuk mencapai BER sebanyak 10–3 dengan SNR sekurang-kurangnya 20 dB. Peringkat modulasi yang lebih tinggi seperti 256–QAM memerlukan SNR sebanyak 50 dB untuk mencapai hasil BER yang sama. Kajian juga menunjukkan prestasi sistem ini tidak tergugat dengan perubahan saiz FFT mahupun panjang prefix-kitaran yang dimasukkan ke dalam isyarat yang dihantar. Walau bagaimanapun, bilangan sub-pembawa bergantung kepada peringkat QAM yang digunakan untuk suatu nilai SNR yang diberi.

Kata kunci: Multiplexan pembahagian frekuensi ortogonal (OFDM), modulasi kuadratur (QAM), pengkodan gray, dan jelmaan fourier pantas

In this paper, we investigate the performance of Gray encoding M–Quadrature Amplitude Modulation (QAM) schemes in Orthogonal Frequency Division Multiplexing (OFDM) transmission over added white Gaussian noise (AWGN) channel. Gray–coded QAM with 1 to 8–bit symbol corresponding to 2 to 256–QAM respectively is generated and fed into OFDM transmission system. Performance in terms of bit error rate (BER) is presented against OFDM fast Fourier transform (FFT) size, subcarrier number, length of cyclic prefix, and tolerance to signal to noise ratio of the channel. Preliminary results show that only 16 and lower level–QAM are attractive to achieve a bit error rate (BER) of 10–3 with signal to noise ratio of at least 20 dB. The higher level QAM such as 256–QAM scheme will require at least a SNR of 50 db to achieve similar outcome. The study also shows that the performance of the system is not affected by the number of fft–points used, or the length of cyclic prefix inserted to the transmitted signal. However, the number of subcarriers does depend on the level of QAM used at a given SNR value.

Keywords: Orthogonal frequency division multiplexing (OFDM), quadrature amplitude modulation (QAM), gray coding, fast fourier transform (FFT)