bluuebunny/crossref_metadata_2025 huggingface dataset:
SIMULATED ANNEALING ALGORITHM FOR SCHEDULING DIVISIBLE LOAD IN LARGE SCALE DATA GRIDS
Authors: Abdullah Monir , Othman MOHAMED , Ibrahim Hamidah , Subramaniam Shamala
Published: October 2018

In many data grid applications, data can be decomposed into multiple independent sub datasets and distributed for parallel execution and analysis. This property has been successfully exploited using Divisible Load Theory (DLT). Many Scheduling approaches have been studied but there is no optimal solution. This paper proposes a novel Simulated Annealing (SA) algorithm for scheduling divisible load in large scale data grids. SA algorithm is integrated with DLT model and compared with the previous approaches. Experimental results show that the proposed model obtains better solution in term of makespan.
TUNABLE BANDPASS FILTER USING RF MEMS SWITCHES
Authors: Alam A.H.M Zahirul
Published: October 2018

A band pass tunable RF filter is proposed by using Radio Frequency (RF) Microelectro Mechanical Systems (MEMS). The tunability is obtained by using capacitive MEMS switches that can be tuned within the bandwidth of 3.6 GHz to 4.4 GHz. The performance of the filter depends on geometry and location and types of the MEMS switches. Optimization has been done to achieve tunability by using 3-D high frequency electromagnetic simulator (HFSS).
FORWARD MASKING THRESHOLD ESTIMATION USING NEURAL NETWORKS AND ITS APPLICATION TO PARALLEL SPEECH ENHANCEMENT
Authors: Gunawan T. S. , Khalifa O. O. , Ambikairajah E.
Published: October 2018

Forward masking models have been used successfully in speech enhancement and audio coding. Presently, forward masking thresholds are estimated using simplified masking models which have been used for audio coding and speech enhancement applications. In this paper, an accurate approximation of forward masking threshold estimation using neural networks is proposed. A performance comparison to the other existing masking models in speech enhancement application is presented. Objective measures using PESQ demonstrates that our proposed forward masking model, provides significant improvements (5-15 %) over four existing models, when tested with speech signals corrupted by various noises at very low signal to noise ratios. Moreover, a parallel implementation of the speech enhancement algorithm was developed using Matlab parallel computing toolbox.
A Linear Relationship between the Mechanical, Thermal and Gas Barrier Properties of MAPE Modified Rubber Toughened Nanocomposites
Authors: Jamal Nur Ayuni
Published: October 2018

Composites based on high density polyethylene (HDPE), ethylene propylene diene monomer (EPDM) and organophilic montmorillonite (OMMT) clays were prepared by melt compounding followed by compression molding. The addition of clay as well as compatibilizer agent (maleic anhydride polyethylene (MAPE)) considerably improved the tensile properties of nanocomposites systems. The largest improvement in mechanical and thermal properties occurred at clay loading levels of 4% (2-8 wt %) with MAPE system. Interestingly, the increased in tensile properties also resulted in improve in thermal and barrier properties. Differential scanning calorimeter analysis (DSC) revealed that the barrier property of nanocomposite was influenced by the crystalline percentage of nanocomposite. Along with crystalline percentage, the crystallization temperature, Tc and melting temperature, Tm were also improved with OMMT and MAPE agent. The d-spacings of the clay in nanocomposites were monitored using x-ray diffraction (XRD) and the extent of delamination was examined by transmission electron microscope (TEM). The wide angle of XRD patterns showed the increased interplanar spacing, d of clay layers, indicating enhanced compatibility between polymer matrix and OMMT with the aid of MAPE agent. TEM photomicrographs illustrated the mixed intercalated and partial exfoliated structures of the nanocomposites with OMMT and MAPE agent.
RETINA FUNDUS IMAGE MASK GENERATION USING PSEUDO PARAMETRIC MODELING TECHNIQUE
Authors: Aibinu Abiodun Musa , SALAMI M.J.E. , SHAFIE A.A.
Published: October 2018

The use of vascular intersection as one of the symptomsfor monitoring and diagnosis of diabetic retinopathy fromfundus images have been widely reported in literatures. Inthis work, a new hybrid approach that makes use of threedifferent methods of vascular intersection detection namelyModified cross-point number (MCN), Combine Cross Points(CNN) and Artificial Neural Network (ANN) is hereby proposed.Result obtained from the application of this techniqueto both simulated and experimental shows a very high accuracyand precision value in detecting both bifurcation andcross over points. Thus an improvement in bifurcation andvascular point detection and a good tool in the monitoringand diagnosis of diabetic retinopathy.
TRACKING AND MONITORING OF TAGGED OBJECTS EMPLOYING PARTICLE SWARM OPTIMIZATION ALGORITHM IN A DEPARTMENTAL STORE
Authors: Bhattacharya Indrajit
Published: October 2018

The present paper proposes a departmental store automation system based on Radio Frequency Identification (RFID) technology and Particle Swarm Optimization (PSO) algorithm. The items in the departmental store spanned over different sections and in multiple floors, are tagged with passive RFID tags. The floor is divided into number of zones depending on different types of items that are placed in their respective racks. Each of the zones is placed with one RFID reader, which constantly monitors the items in their zone and periodically sends that information to the application. The problem of systematic periodic monitoring of the store is addressed in this application so that the locations, distributions and demands of every item in the store can be invigilated with intelligence. The proposed application is successfully demonstrated on a simulated case study.
EXPERIMENTAL DESIGN FOR SIMULTANEOUS PRODUCTION OF PHB, MESOPHILIC PROTEASES AND LIPASES
Authors: Amara Amro Abd al fattah
Published: October 2018

ABSTRACT: Bacillus species are able to produce PHB, Proteases and Lipases. Bacillus subtilius, Bacillus pumilus, Bacillus therigienesis and Bacillus sp. were used. Plackett-Burman, Box-Behnken design and the Excel solver were used to optimize the production. The statistical analysis of the results proved insignificant relationship between the media compositions and the responses. The results clearly proved a competition between the production of PHB, Proteases and Lipases. Meanwhile systematic experimental design succeeded to minimize this competition. The maximum gained PHB in this study were 16.48 g/l/48 hr. In case of Proteases and Lipases were 534, and 22.56 Units/ml/48 h respectively. The strategies used in this study are recommended for simultaneous production of PHB and proteases. For some extend lipases produced too.
TEMPERATURE CONTROL CIRCUIT FOR SURFACE ACOUSTIC WAVE (SAW) RESONATORS
Authors: Mohamad Ashari Zainab , Sidek Fatini , Nordin Anis Nurashikin
Published: October 2018

Surface Acoustic Wave (SAW) resonators are key components in oscillators, frequency synthesizers and transceivers. One of the drawbacks of SAW resonators are that its piezoelectric substrates are highly sensitive to ambient temperature resulting in performance degradation. This work propose a simple circuit design which stabalizes the temperature of the SAW resonator, making it independet of temperature change. This circuit is based on the oven control method which elevates the temperature of the resonator to a high temperature, making it tolerant to minor changes in ambient temperature.This circuit consist of a temperature sensor, heaters and a comparator which turn the heater on or off depending on the ambient temperature. Several SAW resonator were tested using this circuit. Experimental results indicate the temperature coefficient of frequency (TCF) decreases from maximum of 130.44/Â°C to a minimum of -1.11/Â°C.Â
INVESTIGATION OF THERMAL PERFORMANCE OF AIR TO WATER HEAT EXCHANGER USING NANO-FLUIDS
Authors: Saeid Nawaf Hazim
Published: October 2018

In the present study the three-dimensional numerical simulation is selected as a tool to investigate the effectiveness of a cross flow heat exchanger. Water is selected to be mixed with nano-particles and flow inside a circular pipe while a pure air is flowing across it. Numerical simulations is carried out under laminar flow for both water and air sides. The thickness of the pipe is neglected in the present preliminary study. From the physics of the problem, the governing parameters can be determined as: the Reynolds, the type and the volume fraction of the nono-fluid. The effect of these governing parameters is studied and the results are presented. The results show significant enhancement of heat transfer with introduction of nano-particles, such as titanium-oxide (TiO2) nano-powder, compared to the pure base fluid. The accuracy of the results presented in the present study depends on the accuracy of the effective properties of the nano-fluids, which are taken from the open literature. ABSTRAK: Dalam kajian ini, simulasi tiga dimensi berangka digunakan untuk mengkaji keberkesanan penukar haba aliran silang.  Air dipilih untuk dicampurkan dengan zarah bersaiz nano dan dialirkan di dalam paip berbentuk bulat, sementara udara tulen mengalir melaluinya.  Simulasi berangka dijalankan di bawah aliran lamina untuk kedua-dua belah air dan udara. Ketebalan paip diabaikan di dalam kajian permulaan ini.  Dari sudut permasalahan fizik, parameter pengawal imbang boleh ditentukan sebagai: nombor Reynolds, jenis dan isipadu pecahan bendalir nano. Kesan parameter pengawal imbang ini dikaji dan keputusannya dibentangkan.  Keputusan menunjukkan peningkatan pemindahan haba yang ketara dengan penggunaan zarah bersaiz nano seperti serbuk titanium oksida (TiO2), berbanding dengan bendalir tulen.  Ketepatan keputusan kajian ini bergantung kepada ketepatan sifat-sifat efektif bendalir nano yang dirujuk daripada sumber maklumat terdahulu.
Characterization of Materials by Vibration Technique
Authors: Mohd Akil Tan Mohd Hilman
Published: October 2018

This paper presents an experimental investigation of two different kinds of plates of materials namely glass and stainless steel by experimental modal analysis. The materials are excited by an impact hammer to perform resonant vibration where the characteristics of the resonance are acquired. One most important characteristic is the natural frequency where it is known that different material having undergone resonant vibration exhibit different specific natural frequencies to it. The natural frequencies and corresponding mode shapes are used as the parameters of determining the structural properties of these materials. The vibration analysis is done using the LMS instruments and software where Frequency Response Function (FRF) measurement technique is employed in determining the natural frequencies. The structural properties are established based on the obtained natural frequencies and geometries of the materials using the expression from available literature. The elastic moduli obtained for glass and stainless steel are 66.08 Gpa and 193.26 GPa.ABSTRAK: Kertas ini membentangkan kajian mengenai dua bahan plat yang berbeza iaitu kaca dan keluli tahan karat dengan menggunakan analisis ragaman eksperimental. Getaran resonans dijalankan dengan menguja bahan-bahan tersebut dengan tukul hentaman dimana ciri-ciri tertentu diperolehi. Frekuensi asli merupakan satu daripada ciri utama, dimana ianya diketahui bahawa bahan yang berbeza akan mengalami getaran resonans yang menghasilkan frekuensi asli tertentu. Frekuensi asli dan bentuk ragam yang berpadanan digunakan sebagai parameter dalam menentukan sifat-sifat struktur bahan ini. Analisis getaran dijalankan dengan menggunakan peralatan LMS dan teknik ukuran perisian Fungsi Frekuensi Sambutan (Frequency Response Function (FRF)) untuk menentukan frekuensi asli. Sifat-sifat struktur ditentukan berdasarkan frekuensi asli dan bahan geometri, yang diperolehi daripada pengungkapan bahan sumber bacaan yang sedia ada. Modulus keanjalan yang diperolehi untuk kaca adalah 66.08 GPa dan untuk keluli tahan karat adalah 193.26 GPa.
STRUCTURAL IDENTIFICATION OF DISTINCT INVERSIONS OF PLANAR KINEMATIC CHAINS
Authors: Sanyal Dr. Shubhashis
Published: October 2018

Inversions are various structural possibilities of a kinematic chain. The number of inversions depends on the number of links of a kinematic chain. At the stage of structural synthesis, identification of distinct structural inversions of a particular type of kinematic chain is necessary. Various researchers have proposed methods for identification of distinct inversions. Present method based on Link joint connectivity is proposed to identify the distinct inversions of a planar kinematic chain. Method is tested successfully on single degree and multiple degree of freedom planar kinematic chains. ABSTRAK: Penyonsangan merupakan kebarangkalian pelbagai struktur suatu rangkaian kinematik. Jumlah songsangan bergantung kepada jumlah hubungan suatu rangkaian kinematik. Pada peringkat sintesis struktur, pengenalan songsangan struktur yang berbeza untuk suatu jenis rangkaian kinematik adalah perlu. Ramai penyelidik telah mencadangkan pelbagai kaedah pengenalan songsangan yang berbeza. Kaedah terkini berdasarkan hubungan kesambungan bersama telah dicadangkan untuk mengenalpasti songsangan yang berbeza dalam suatu satah rangkaian kinematik.
PERFORMANCE DETERIORATION OF THERMOSIPHON SOLAR FLAT PLATE WATER HEATER DUE TO SCALING
Authors: Chandavar Arunachala umesh
Published: October 2018

The performance of Flat plate Solar Water Heater deteriorates within five to twelve years of their installation due to factors related to manufacturing, operating conditions, lack of maintenance etc. Especially, problem due to scaling is significant as it is based on quality of water used. The remaining factors are system dependent and could be overcome by quality production. Software is developed by incorporating Hottel Whillier Bliss (H-W-B) equation to ascertain the effect of scaling on system efficiency in case of thermosiphon system. In case of clean thermosiphon system, the instantaneous efficiency calculated at 1000 W/m2 radiation is 72 % and it drops to 46 % for 3.7 mm scale thickness. The mass flow rate is reduced by 90 % for 3.7 mm scale thickness. Whereas, the average temperature drop of water in the tank is not critical due to considerable heat content in water under severe scaled condition.  But practically in case of major scale growth, some of the risers are likely to get blocked completely which leads to negligible temperature rise in the tank. ABSTRAK: Prestasi plat rata pemanas air suria merosot selepas lima hingga dua belas tahun  pemasangannya disebabkan faktor-faktor yang berkaitan dengan pembuatannya, cara kendaliannya, kurangnya penyelenggaraan dan sebagainya.  Terutama sekali, masalah disebabkan scaling (tembunan endapan mineral) perlu diambil berat kerana ianya bergantung kepada kualiti air yang digunakan. Faktor-faktor selebihya bersandarkan sistem dan ia boleh diatasi dengan mempertingkatkan kualiti pembuatannya. Perisian komputer dihasilkan dengan menggunakan persamaan Hottel Whillier Bliss (H-W-B) untuk menentukan  kesan scaling terhadap kecekapan sistem dalam termosifon. Dalam sistem termosifon bersih, kecekapan seketika dikira pada 1000 W/m2 , pada kadar radiasi 72 % dan ianya jatuh kepada 46 % untuk ketebalan skala 3.7 mm. Kadar aliran jisim berkurangan sebanyak 90 % untuk ketebalan skala 3.7 mm. Manakala, penurunan suhu purata air di dalam tangki tidaklah kritikal, disebabkan oleh kandungan haba yang tinggi di dalam air di bawah keadaan  kerak yang teruk. Tetapi dalam kes tumbesaran kerak yang genting, sesetengah penaik akan tersumbat sepenuhnya, mengakibatkan peningkatan suhu di dalam tangki boleh diabaikan.
Enhanced Cancer Cell (HeLa) Killing Efficacy of Mixed Î‘lpha and Gamma Iron Oxide Superparamagnetic Nanoparticles under Combined AC (Alternating Current) Magnetic-Field and Photoexcitation
Authors: And Yuji Horie Md. Shariful Islam, Yoshihumi Kusumoto, Md. Abdulla Al-Mamun
Published: October 2018

We synthesized mixed α and γ-Fe2O3 nanoparticles and investigated their toxic effects against HeLa cells under induced AC (alternating current) magnetic-fields and photoexcited conditions at room temperature. The findings revealed that the cell-killing percentage was increased with increasing dose for all types of treatments. Finally, 99% cancer cells were destructed at 1.2 mL dose when exposed to combined AC magnetic-field and photoexcited conditions (T3) whereas 89 and 83 % of HeLa cells were killed under only AC magnetic-field induced (T1) or only photoexcited (T2) condition at the same dose.ABSTRAK: Campuran α dan zarah γ-Fe2O3 bersaiz nano disintesiskan dan kesan toksidnya terhadap sel HeLa dikaji dibawah aruhan medan magnet arus ulang-alik (alternating current (AC)) dan keadaan photoexcited (proses ransangan atom atau molekul suatu bahan dengan penyerapan tenaga sinaran) pada suhu bilik. Penemuan mendedahkan bahawa peratusan sel yang musnah bertambah dengan pertambahan dos untuk semua jenis rawatan. Akhirnya, 99% sel kanser dimusnahkan pada kadar dos 1.2mL setelah didedahkan terhadap kombinasi medan magnet AC dan keadaan photoexcited (T3) dimana 89% dan 83% sel HeLa dimusnahkan dengan hanya di bawah aruhan medan magnet AC (T1) atau hanya pada keadaan photoexcited (T2) pada kadar dos yang sama.KEY WORDS : Cancer, Hyperthermia, Iron oxide nanoparticles, Heat dissipation,    Cytotoxicity, HeLa cell.
Isolation of Lactic Acid Bacteria from Malaysian Non-Broiler Chicken (Gallus gallus) Intestine with Potential Probiotic for Broiler Feeding
Authors: Tengku Abdul Hamid Tengku Haziyamin , Ezani And Ezureen
Published: October 2018

Probiotic supplement can function as substitute for antibiotics especially in the broiler chicken feeding which can form an integral part of organic farming. Broiler forms one of an important protein source in South East Asia. Lactic acid bacteria (LAB) are important inhabitants of animal intestine and are useful source of probiotic microorganisms. Non-broiler chicken could be an ideal source of probiotic microorganisms that can be utilized for large scale broiler feeding. Our studies have successfully identified, through morphological and biochemical tests, 11 LAB isolates from gastrointestinal tract of local non-broiler chicken (Gallus gallus). These isolates have the ability to utilize lactose as part of their metabolism process and all showed negative reactions on catalase test. Out of the eleven (11) isolates, three (3) isolates were Gram-positive cocci and remaining isolates were of Gram-positive bacilli. Three isolates (E4, E11 and E17) showed at least 10 mm inhibitory effects on disc diffusion test against pathogenic bacteria Salmonella typhimurium. The partial 16S rRNA gene sequencing showed that one isolate (E17) has 89% similarity with Lactobacillus rhamnosus. These LAB strains isolated from Malaysian domestic non-broiler chicken gastrointestinal tract can potentially be used as a component for probiotics formulation in poultry feeding.ABSTRAK: Makanan tambahan probiotik boleh berfungsi sebagai pengganti antibiotik terutamanya dalam pemakanan ayam pedaging yang akan membentuk bahagian kamiran dalam penternakan organik. Ayam pedaging merupakan sumber protein penting di Asia Tenggara. Bakteria asid laktik (lactic acid bacteria (LAB)) merupakan penghuni penting dalam usus haiwan dan merupakan sumber penting dalam mikroorganisma probiotik. Ayam bukan pedaging sesuai dijadikan sumber mikroorganisma probiotik agar dapat digunakan sebagai pemakanan ayam pedaging secara besar-besaran. Kajian telah berjaya mengenal pasti, melalui kaedah morfologi dan uji kaji biokimia, 11 LAB diasingkan daripada salur gastrousus ayam bukan pedaging (Gallus gallus). Pencilan ini berupaya menggunakan laktosa sebagai sebahagian daripada proses metabolisma dan semuanya menunjukkan kesan negatif terhadap ujian katalase. Daripada sebelas (11) pencilan, tiga (3) pencilan adalah kokus gram-positif dan pencilan yang lainnya adalah basilus gram-positif. Tiga pencilan (E4, E11 dan E17) menunjukkan sekurang-kurangnya 10 mm kesan rencatan terhadap ujian resapan cakera terhadap bakteria patogen Salmonella typhimurium. Sebahagian daripada urutan gen 16S rRHA menunjukkan bahawa satu pencilan (E17) mempunyai 89% persamaan dengan Lactobacillus rhamnosus. Strain LAB ini diasingkan daripada salur gastrousus ayam tempatan bukan pedaging, sesuai digunakan sebagai komponen untuk rumusan probiotik dalam pemakanan ayam-itik.
Removal of Oil and Grease as Emerging Pollutants of Concern (EPC) in Wastewater Stream
Authors: Abass O Alade , Jameel Ahmad T. , Muyubi Suleyman A. , Abdul Karim Mohamad I. , Alam And Md. Zahangir
Published: October 2018

Wastewater characteristics, which depend on wastewater source, are increasingly becoming more toxic in recent times. The concentrations of oil and grease in wastewater streams have been observed to increase in wastewater stream with increasing adverse effects on the ecology. This results from the increasing use of oil and grease in high-demanded oil-processed foods, establishment and expansion of oil mills and refineries worldwide, as well as indiscriminate discharge of oil and grease into the water drains, domestically and industrially. This study reports the applications, efficiencies and challenges of the wastewater treatment techniques currently employed in the removal of oil and grease from the industrial wastewater and municipal water stream. The results shows that the concentrations of oil and grease injected into the ecosystem are of higher environmental impact and this needs to be given the desired attention. The desired development for effective removal of oil and grease as emerging pollutants of concern (EPC) in wastewater stream are thus proposed. ABSTRAK: Ciri-ciri air sisa, bergantung kepada punca air sisa tersebut, menjadi semakin toksik akhir-akhir ini. Kepekatan minyak dan gris dalam air sisa anak sungai dilihat makin bertambah dalam air sisa anak sungai dengan bertambahnya kesan negatif ke atas ekologi. Ini disebabkan oleh peningkatan penggunaan minyak dan gris dalam makanan berproses yang tinggi permintaannya, penubuhan dan perkembangan kilang pertroleum dan loji penapisan di seluruh dunia. Minyak dan gris juga dibuang sewenang-wenangnya ke dalam parit air, dari kalangan domestik dan industry. Kajian ini membentangkan tentang aplikasi, keberkesanan dan teknik cabaran rawatan air buangan yang kini digunakan dalam pembuangan minyak dan gris dari air sisa industry dan air sungai perbandaran. Keputusan menunjukkan kepekatan minyak dan gris yang wujud dibuang ke dalam ekosistem mempunyai impak yang lebih tinggi terhadap persekitaran dan hal ini perlu diambil berat. Keinginan untuk kemajuan penyingkiran minyak dan gris sebagai keprihatinan terhadap pencemaran (emerging pollutants of concern (EPC))ke atas air sisa sungai dicadangkan.Key words: wastewater, oil and grease, emerging pollutant of concern
Mammalian Cell Culture Clarification: A Case Study Using Chimeric Anti-CEA Monoclonal Antibodies
Authors: Abol Hassan Mohamed Ali , Mohammad Abdul Wahab , Abdul Rahman And Badarulhisam
Published: October 2018

The extracellular expression of monoclonal antibodies (mAbs) in mammalian cell culture provides both opportunities and restrictions for the design of robust harvest and clarification operations. With advances in cell culture media and cell lines, it is now possible to achieve high titers of over 5 g/l for mAbs. However, Mammalian cells are sensitive to breakage due to shear stress that can result in release of proteases and other host cell proteins (HCPs) which eventually affects product stability and purity. There is larger number of mAbs undergoing clinical development and it has placed significant importance on platform technologies of process development. Generally, Centrifugation and microfiltration are the primary harvest techniques used in the industry and depth filtration is also used as a step operation on clarification. This study compares the unit operations; centrifugation, microfiltration and depth filtration for maximum recovery of monoclonal antibodies. The results have shown that the depth filtration as more suitable operation for mammalian cell culture clarification since it gives 96% recovery of mAbs in comparison to centrifugation and microfiltration. ABSTRAK: Pengungkapan luar sel dari antibodi monoklon (monoclonal antibodies ((mAbs) dalam kultur sel mamalia memberi ruang dan batasan terhadap reka bentuk penuaian yang cekap dan penerangan operasi. Dengan kemajuan dalam media sel kultur dan cell lines (produk yang berupa sel kekal yang digunakan untuk tujuan kajian biologi), kini adalah berkemungkinan untuk memperolehi titer tinggi melebihi 5g/l untuk mAbs [2]. Walaupun begitu, sel mamalia sensitif terhadap retakan disebabkan tegasan ricih yang menyebabkan pengeluaran protease dan hos sel protein yang lain, (host cell proteins (HCPs)) akhirnya mempengaruhi kestabilan dan keaslian produk. Terdapat mAbs dalam jumlah besar yang masih menjalani pembangunan klinikal dan sesungguhnya ini penting sebagai satu landasan teknologi dalam proses pembangunan. Umumnya pengemparan dan mikropenurasan merupakan teknik asas tuaian dalam industri dan penurasan dalam juga digunakan sebagai satu pengendalian langkah dalam penjelasannya. Kajian ini membandingkan operasi unit: pengemparan, mikropenurasan dan penurasan dalam untuk perolehan antibodi monoklon yang maksima. Keputusan menunjukkan penurasan dalam adalah operasi yang lebih sesuai untuk penjelasan kultur sel mamalia kerana ia memberikan perolehan 96 % mAbs berbandingkan dengan cara pengemparan dan mikropenurasan.
Modification of ITU-R Rain Fade Slope Prediction Model Based on Satellite Data Measured at High Elevation Angle
Authors: Dao Hassan , Islam Md. Rafiqul , Al-Khateeb Khalid
Published: October 2018

Rain fade slope is one of fade dynamics behaviour used by system engineers to design fade mitigation techniques (FMT) for space-earth microwave links. Recent measurements found that fade slope prediction model proposed by ITU-R is unable to predict fade slope distribution accurately in tropical regions. Rain fade measurement was conducted  in Kuala Lumpur (3.3° N, 101.7° E) where located in heavy rain zone by receiving signal at 10.982 GHz (Ku-band) from MEASAT3 (91.5° E) on 77.4° elevation angle. The measurement has been carried out for one year period. Fade slope S parameter on ITU-R prediction model has been investigated. New parameter is proposed for the fade slope prediction modeling based on measured data at high elevation angle, Ku-band. ABSTRAK: Cerun hujan pudar adalah salah satu dinamik tingkah laku pudar yang digunakan oleh jurutera sistem untuk mereka bentuk teknik-teknik pengurangan pudar (FMT) bagi link gelombang mikro ruang bumi. Ukuran baru-baru ini mendapati bahawa cerun pudar ramalan model yang dicadangkan oleh ITU-R tidak mampu untuk meramalkan pengagihan cerun pudar tepat di kawasan tropika. Pengukuran  hujan pudar telah dijalankan di Kuala Lumpur (3.3° N, 101.7° E) yang terletak di kawasan hujan lebat dengan menerima isyarat pada 10,982 GHz (Ku-band) dari MEASAT3 (91.5° E) pada sudut ketinggian 77.4°. Pengukuran telah dijalankan untuk tempoh satu tahun. Parameter cerun pudar S pada model ramalan ITU-R telah disiasat. Parameter baru adalah dicadangkan untuk pemodelan cerun pudar ramalan berdasarkan data yang diukur pada sudut paras ketinggian, Ku-band.KEYWORDS: fade slope; ITU-R; fade mitigation techniques; sampling time interval
Iterative Spatial Sectoring: An Extention of Simpsonâ€™s Rule for Determining Area of Irregular Close Shape
Authors: Aboaba Abdulfattah , A. Hameed Shihab , Khalifa Othman O , Abdalla Aisha H.
Published: October 2018

Just as the method for determining the properties of shapes like  triangles, parallelogram, cuboids, and geometric figures like circle, and spheres have standard formulae, the determination of a function F(x) in many dimensions have formulae or standard methods. Complex 2D and 3D figures consisting of intricate merger of regular shapes have had their parameters determined through careful separation and determination of the properties of individual components that make up the figure.  Moreover, the case of irregular close shapes mostly but not limited to 2D and 3D which abound in science and engineering have equally received attention resulting in lots of approximation method evolved over time. The Iterative spatial sectoring is a novel way of determining the area of 2D irregular close shape by expanding on the famours Simpson’s method for finding the area of a function F(x) whose definite integral is either tedious or impossible by standard approaches. ABSTRAK: Seperti beberapa kaedah yang ada yang sering kali digunakan untuk menentukan sifat-sifat bentuk seperti segi tiga, segi empat selari, kuboid, dan rajah geometrik seperti bulatan, dan sfera; semuanya mempunyai formula-formula yang standard, penentuan fungsi F(x). Bentuk kompleks dua dimensi, 2D dan tiga dimensi, 3D terdiri daripada penyatuan rumit bentuk-bentuk yang biasa dimana parameternya ditentukan melalui pengasingan yang cermat dan penentuan ciri-ciri komponen individu yang akhirnya membentukkannya. Walaupun begitu, dalam hal bentuk tertutup yang tak nalar, ia bukan hanya terhad kepada bentuk 2D dan 3D yang banyak terdapat dalam bidang sains dan kejuruteraan.  Ia mendapat perhatian meluas dimana pelbagai kaedah penghampiran dihasilkan.  Pensektoran ruang berlelar merupakan cara baru yang digunakan untuk menentukan keluasan bentuk  2D tak nalar yang bertutup  dengan mengembangkan kaedah Simpson’s untuk mendapatkan keluasan dengan fungsi F(x) dimana kamirannya sama ada terlalu rumit ataupun di anggap mustahil mengikut cara biasa.KEYWORDS: function F(x); irregular shape; Simpson’s method; definite integral; iterative spatial sectoring
UNSTEADY HEAT TRANSFER IN AN ANNULAR PIPE. PART II: SWIRLING LAMINAR FLOW
Authors: Seng Kelvin Ho Choon
Published: October 2018

The   heat  transfer   problem  in   magnetocaloric regenerators  during  magnetization  has  been  described  and investigated for convective heat transfer by means of axial flow in part I of this series.   This work will focus on enhancing the unsteady heat  transfer using swirling laminar flow generated using axial vanes.   The governing parameters for this  studyare,  the  D*  ratio  (Inner  diameter/Outer  diameter)  and  the swirl number, S.   The study is conducted  using  dimensional analysis and commercial CFD codes provided by ANSYS CFX. The  hydrodynamics and the  heat transfer of the  model are compared with data from similar cases found in literature and is found to be in the vicinity of good agreement.Keywords-  Annular ducts; unsteady heat transfer;  magnetic refrigeration/cooling;   swirling   laminar    flow;    dimensional analysis.
Evaluation of Sustainable Development Indicators With Fuzzy TOPSIS Based on Subjective and Objective Weights
Authors: Nik Zahari Nang Idayu , Abdullah Mohd Lazim
Published: October 2018

ABSTRACT: Sustainable development aims at improving and maintaining the well-being of people and the ecology. However, this paper focuses only on the ecological aspects. The selection of the proper ecological protection determinant plays a very important role in improving the environment of Malaysia. This paper will propose a method from Wang and Lee (2009), and Yong (2006) which applies a fuzzy TOPSIS method -- based on subjective and objective weights â€“ to make the required selection. Four alternatives will be tested which are: prevent pollution (A1), conservation (A2), well-manage (A3), and public awareness (A4). Along with these, four criteria need to be considered: water quality factor (C1), land integrity factor (C2), air quality factor (C3), and biodiversity factor (C4). Finally, a numerical example of ecological protection determinant selection is used to illustrate the proposed method.Â ABSTRAK: Pembangunan lestari bermatlamat memperbaiki dan mengekalkan kesejahteraan rakyat serta ekologi. Walau bagaimanapun, kertas kajian ini hanya memberi tumpuan kepada aspek-aspek ekologi. Pemilihan penentu perlindungan serta keselamatan bagi aspek ekologi memainkan peranan yang amat penting dalam meningkatkan kualiti alam sekitar di Malaysia. Kertas kajian ini telah menggunakan kaedah Wang dan Lee (2009) dan Yong (2006) yang mengaplikasikan kaedah TOPSIS kabur berdasarkan pemberat subjektif dan objektif. Terdapat empat alternatif yang akan diuji iaitu: pencegahan pencemaran (A1), pemuliharaan (A2), pengurusan yang baik (A3), kesedaran orang awam (A4). Selain itu, terdapat empat kriteria yang perlu dipertimbangkan: faktor kualiti air (C1), faktor kualiti tanah (C2), faktor kualiti udara (C3), faktor kepelbagaian biologi (C4). Kesimpulannya, contoh pengiraan untuk memperoleh penentu pemilihan perlindungan ekologi telah digunakan bagi menunjukkan kaedah yang dicadangkan.KEYWORDS: sustainable development; ecological factors; subjective and objective weight; fuzzy TOPSIS
Performance Analysis of a Free Space Optics Link with Multiple Transmitters/Receivers
Authors: Md Noor Nur Haedzerin , Naji Ahmed Wathik , Al-Khateeb Wajdi
Published: October 2018

ABSTRACT: Â Multiple transmitters/receivers (TX/RX) are used to improve the quality of Free Space Optics (FSO) communication systems. With the current needs of this technology for longer distance communication, the qualitative analysis of the system has become essential. In this work, the received power level (PR) and bit error rate (BER) are considered to influence the FSO link performance. The relationship between the two parameters are investigated and analysed. Furthermore, the received power for various numbers of TXs and RXs are experimentally measured and compared with the values obtained from theoretical calculations. The first part of the work deals with the theoretical calculation and simulation designs of multiple laser beams based on the commercial FSO used in actual sites. The second part describes the practical work and analysis of the systemâ€™s performance.ABSTRAK: Pemancar/penerima berganda (TX/RX) digunakan bagi meningkatkan kualiti sistem komunikasi Ruang Optik Bebas (FSO). Analisis kualitatif ke atas sistemnya adalah penting bagi keperluan semasa teknologi ini untuk jarak jauh. Di dalam kajian ini, aras kuasa penerima (PR) dan kadar ralat bit (BER) telah diambilkira bagi menentukan prestasi rangkaian FSO. Hubungan di antara kedua-dua parameter telah dikaji dan dianalisis. Seterusnya, kuasa penerima untuk pelbagai nombor TXs dan RXs diukur secara eksperimen dan dibandingkan dengan nilai teori yang dikira. Bahagian pertama skop kajian berkaitan dengan pengiraan teori dan rekabentuk simulasi sinaran laser berdasarkan FSO komersial di lapangan. Bahagian kedua kajian adalah kerja lapangan dan analisis prestasi sistem.KEY WORDS:Â  Free Space Optics (FSO) link; Multiple TX/RX FSO; bit error rate (BER); eye diagram.
Propanoyl(1Z)-N-(2,6-dimethylphenyl)-2-oxopropanehydrazonoate as inhibitor for corrosion of 6061 Al alloy15 % (v) SiC(p) composite in hydrochloric acid media
Authors: U Achutha Kini , Shetty Prakasha , S Divakara Shetty , Herle Ramadev , Isloor Arun
Published: October 2018

ABSTRACT: The corrosion inhibition effect of Propanoyl(1Z)-N-(2,6-dimethylphenyl)-2-oxopropanehydrazonoate (PDOH) in the corrosion of 6061 Aluminium alloy-15%(v) SiC(p)Â composite in 0.5 and 1M hydrochloric acid medium at four different temperatures (30, 40, 50 and 60 â°C) was investigated using potentio-static polarization (Tafel extrapolation and Linear polarization) and weight loss methods. The results obtained reveal that PDOH is an efficient corrosion inhibitor with around 96% inhibition efficiency within the range of temperature studied. Leftward and downward shifts in Tafel plots were observed with the addition of the inhibitor, indicating that PDOH inhibits the corrosion process effectively, and that it is a cathodic inhibitor. Corrosion rate increases and inhibition efficiency decreases with increase in temperature. Results obtained by Tafel extrapolation, linear polarization, and weight loss methods are in agreement. The adsorption of the inhibitor onto the surface of the 6061 Al alloy 15 % (v) SiC(p)Â composite is found to obey Temkins' adsorption isotherm that verifies the assumption of mono-layer adsorption on a uniform homogeneous composite surface with an interaction in the adsorption layer. The inhibition is therefore governed by the physisorption mechanism.ABSTRAK: Kesan perencatan kakisan Propanoyl(1Z)-N-(2,6-dimethylphenyl)-2-oxopropanehydrazonoate (PDOH) ke atas kakisan komposit aloi Al 6061-15%(v) SiC(p) dalam media asid hidroklorik 0.5 dan 1M pada suhu-suhu yang berbeza (30, 40, 50 dan 60â°C) telah dikaji menggunakan polarisasi statik-upaya (extrapolarisasi Tafel dan polarisasi Linear) dan kaedah kehilangan berat. Keputusan diperolehi menunjukkan PDOH adalah perencat yang efisien dengan 96 % keupayaan perencatan bagi julat suhu yag dikaji. Anjakan ke kiri dan ke bawah plot Tafel dapat dilihat dengan penambahan perencat, menunjukkan PDOH merencatkan proses kakisan dengan berkesan, dan ia adalah perencat katodik. Dengan peningkatan suhu, kadar kakisan meningkat dan keberkesanan perencatan menurun. Keputusan dari ekstrapolasi Tafel, polarisasi linear dan kehilangan berat.adalah saling bersetuju antara satu sama lain. Penjerapan perencat ke atas permukaan komposit aloi 6061 Al alloy 15 % (v) SiC(p) memenuhi penjerapan Temkinsâ€™ isoterma yang mengesahkan andaian penjerapan lapisan-mono ke atas permukaan komposit homogenus yang seragam melalui interaksi pada lapisan penjerapan. Perencatan dikawal oleh mekanisma fizijerapan.
A VOLTAGE STABILIZER FOR A MICROGRID SYSTEM WITH TWO TYPES OF DISTRIBUTED GENERATION RESOURCES
Authors: Mahzarnia Maedeh , Sheikholeslami Abdolreza , Adabi J.
Published: October 2018

ABSTRACT:Â Microgrids are used as controllable units connected to power grid, in which the electrical distances between reactive power sources and the loads that need the reactive compensation are not too much. Thus, a coordinated compensation of reactive sources has to be implemented in order to avoid a fast voltage collapse by proposing a Microgrid Voltage Stabilizer (MGVS). This stabilizer is desirable to improve the dynamic voltage profile and is tested at a 21-bus IEEE microgrid system. In order to verify the performance of this stabilizer, three distributed generation (DG) resources are utilized in this microgrid (Two PV resources which are categorized as power-electronic converter based on DG and a diesel generator which is known as synchronous machine-based on DG). At first, the mentioned resources and all of their needed equipments are modeled. Then a control model of the stabilizer with appropriate parameters for the proposed microgrid is presented. Voltage deficiency of the system is the input of the stabilizer, and the output signal of the stabilizer, is divided between the DGs in order to provide required reactive power. The dynamic voltage profile of buses in the presence of MGVS and its absence has been compared by implying disturbances. Simulation results in MATLAB/SIMULINK show that the dynamic voltage profile of the buses improves satisfactorily with the addition of MGVS.Â ABSTRAK: Grid mikro digunakan sebagai unit kawalan yang disambungkan kepada grid kuasa, di mana jarak elektrikal antara sumber kuasa reaktif dan bebanan yang memerlukan kompensasi reaktif tidak terlalu besar.Â  Dengan itu, kompensasi yang selaras dengan sumber reaktif perlu diimplimentasikan untuk mengelak kegagalan voltan pantas dengan menggunakan Grid Mikro Penstabil Voltan (Microgrid Voltage Stabilizer - MGVS). Penstabil ini sesuai digunakan untuk meningkatkan profil voltan dinamik dan telah diuji ke atas sistem mikro grid 21-bus IEEE. Untuk memastikan keupayaan penstabil ini, tiga sumber penjanaan agihan (distributed generation - DG) telah digunakan (dua sumber PV yang dikategorikan sebagai pengubah kuasa elektronik berdasarkan DG dan penjana diesel yang dikenali sebagai mesin segerak berasaskan DG). Mulanya, semua sumber dan alatan yang diperlukan, diilustrasikan. Kemudian, satu model penstabil kawalan bersama parameter yang sesuai dengan mikro grid yang dikemukakan. KetakcukupanÂ  voltan dalam sistem merupakan input penstabil, isyarat keluaran penstabil kemudiannya dibahagikan antara kesemua DG agar ia dapat menyalurkan kuasa reaktif yang diperlukan. Profil voltan dinamik setiap bus dengan kehadiran MGV dan ketidakhadirannya dibandingkan dengan mengimplikasikan gangguan. Keputusan simulasi menggunakan MATLAB/SIMULINK menunjukkan bahawa profil voltan dinamik setiap bus meningkat pada kadar yang memuaskan dengan kehadiran MGVS.
MEMS-BASED OSCILLATORS: A REVIEW
Authors: Karim Jamilah , Alam A. H. M. Zahirul , Nordin Anis Nurashikin
Published: October 2018

ABSTRACT: This paper presents an overview of microelectromechanical (MEMS) based oscillators. The accuracy and stability of the reference frequency will normally limit the performance of most wireless communication systems. MEMS technology is the technology of choice due to its compatibility to silicon, leading to integration with circuits and lowering power consumption. MEMS based oscillators also provide the potential of a fully integrated transceiver. The most commonly used topology for MEMS based oscillators are pierce oscillator circuit topology and TIA circuit topology. Both topologies result in very competitive output in terms of phase noise and power consumption.Â  They can be used for either higher or lower Rx. The major difference between both topologies is the number of transistors used. TIA circuit used more number of transistor compare to pierce circuit. Thus design complexity of the TIA is higher. Pierce circuit is simpler, provide straightforward biasing and easier to design. The highly integratable of MEMS-based oscillators have made them much needed in future multiband wireless system. So that future wireless systems are able to function globally without any problem.

ABSTRAK: Kertas kerja ini membentangkan gambaran keseluruhan mikroelektromekanikal (MEMS) berdasarkan pengayun.Â  Ketepatan dan kestabilan frekuensi rujukan sering membataskan perlaksanaan kebanyakan sistem komunikasi tanpa wayar. Teknologi MEMS merupakan teknologi pilihan memandangkan ia serasi dengan silikon; membolehkan integrasi dengan litar dan penggunaan tenaga yang rendah.Â  Pengayun berdasarkan MEMS jugaÂ  berpotensi sebagai integrasi penuh penghantar-terima. Topologi yang sering digunakan untuk pengayun berdasarkan MEMS adalah topologi litar pengayun pencantas dan topologi litar TIA.Â  Keputusan bagi kedua-dua topologi adalah amat kompetitif dari segi fasa bunyi dan penggunaan tenaga. Ia boleh digunakan untuk meninggikan atau merendahkan Rx. Perbezaan utama di antara kedua-dua topologi adalah bilangan transistor yang digunakan. Litar TIA menggunakan bilangan transistor yang lebih daripada litar pencantas.Â  Maka, rekaan TIA adalah lebih rumit.Â  Litar pencantas adalah lebih ringkas, memberikan pincangan yang jelas dan rekabentuk yang mudah. Pengayun berdasarkan MEMS amat bersepadu menjadikan ia sesuai sebagai sistem tanpa wayar berbilang jalur masa depan.Â  Jesteru sistem tanpa wayar dapat berfungsi pada peringkat global tanpa sebarang kesulitan.
THE CAUCHY PROBLEM FOR THE SYSTEM OF EQUATIONS OF THERMOELASTICITY IN E^n
Authors: Niyozov Ikbol E. , Makhmudov O. I.
Published: October 2018

ABSTRACT: In this paper we consider the problem of analytical continuation of solutions to the system of equations of thermoelasticity in a bounded domain from their values and values of their strains on a part of the boundary of this domain, i.e., we study the Cauchy problem. ABSTRAK: Di dalam kajian ini, kami menyelidiki masalah keselanjaran analitik bagi penyelesaian-penyelesaian terhadap sistem persamaan-persamaan termoelastik di dalam domain bersempadan berdasarkan nilai-nilainya dan nilai tegasannya bagi sebahagian daripada sempadan domain tersebut, iaitu kami mengkaji masalah Cauchy.
APPROXIMATE FUNCTION FOR UNSTEADY AERODYNAMIC KERNEL FUNCTION OF AEROELASTIC LIFTING SURFACES
Authors: Sulaeman Erwin , Ahmed Layeeq
Published: October 2018

ABSTRACT: Prediction of unsteady aerodynamic loads is still the most challenging task in flutter aeroelastic analysis. Generally the numerical estimation of steady and unsteady aerodynamic of thin lifting surface is conducted based on an integral equation relating aerodynamic pressure and normal wash velocity. The present work attempts to increase the accuracy of the prediction by using an approximate approach to evaluate kernel function occurring in the integral equation in the form of cylindrical function.Â  Following previous approximation approach by other researchers to solve the cylindrical function for planar lifting surfaces, in the present work such approach is extended to non planar lifting surfaces.Â  To increase the accuracy of the method, the integration region of the kernel function is divided into two parts namely near and far regions, where a nonlinear regression curve fitting technique is adapted to approximate the denominator part of the cylindrical function of each region.ABSTRAK: Penelahan daya aerodinamik tidak stabil merupakan satu tugas yang mencabar dalam menganalisis getaran aeroanjalan. Umumnya, anggaran berangka untuk daya aerodinamik stabil dan tidak stabil pada permukaan mengangkat yang nipis, adalah berdasarkan kepada persamaan kamiran di antara tekanan aerodinamik danÂ halaju aliran udara pada garis normal yang terhasil di bawah sayap pesawat. Kajian ini adalah bertujuan untuk menghasilkan penelahan daya aerodinamik yang lebih tepat dengan menggunakan pendekatan kira hampir untuk menilai fungsi Kernel yang terdapat dalam persamaan kamiran dalam bentuk fungsi silinder. Dengan menggunakan pendekatan kira hampir yang digunakan oleh penyelidik sebelumnya untuk menyelesaikan fungsi silinder pada permukaan mengangkat satah, kajian ini mengembangkan pendekatan tersebut kepada permukaan mengangkat tak sesatah. Untuk meningkatkan lagi ketepatan penelahan, kawasan pengamiran fungsi Kernel dibahagikan kepada dua bahagian, kawasan hampir dan kawasan jauh, di mana penyuaian lengkung regresi tak linear digunakan untuk kiraan hampir penyebut pada fungsi silinder pada setiap kawasan.