Skip Navigation LinksVolume : Volume 11 No.2 2002

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the_production_and_application_of_powder_metallurgy_pm_high-speed_steels_an_introduction_to_malaysian_industries.pdfTHE PRODUCTION AND APPLICATION OF POWDER METALLURGY (PM) HIGH-SPEED STEELS: AN INTRODUCTION TO MALAYSIAN INDUSTRIES
ABSTRACT: The reason for choosing Powder Metallurgy (PM) processes is not only economical; other reasons include its ability to produce high quality parts, possibility of accurate dimensional control, obtaining homogeneous microstructural and mechanical properties, and also their low effect on the environment. High-speed steels are not exceptional, and during the last decades, not only the demand of high-speed steels produced by PM has grown but also new applications for these steels have appeared . KEYWORDS: High-speed steels, powder metallurgy, compaction, sintering Author: Mohd Asri Selamat
Year: 2002
synthesis_and_evaluation_of_homogeneous_and_crosslinked_chitosan-based_membranes.pdfSYNTHESIS AND EVALUATION OF HOMOGENEOUS AND CROSSLINKED CHITOSAN-BASED MEMBRANES
ABSTRACT: The ultimate goal of this project is to fabricate chitosan-based membranes from domestic shrimp shells, which were collected from a local market. Characterisations of the membranes were studied for the dehydration of isopropanol-water mixtures. Extraction of chitosan from shrimp shells was carried using strong acid and alkal i. A preweighed quantity of chitosan was first dissolved in 10 wt.% aqueous acetic acid solution to produce a casting chitosan solution. The resulting optical clear chitosan solution was cast onto petri dishes and dried at room temperature, followed by alkaline treatment. The homogeneous chitosan membranes obtained were further modified to prepare crosslinked membranes. The dry homogeneous membranes were immersed in a solution of sulphuric acid for a certain period of time. Homogeneous membranes were seen to have higher degrees of swelling and permeation flux but lower separation factor when compared to crosslinked membranes. KEYWORDS: Chitosan; shrimp shells; extraction; homogeneous; crosslinked Author: A. L. Ahmad, W. K. Ng and S. H. Tan
Year: 2002
pencirian_membran_penurasan_nano_yang_dihasilkan_menggunakan_kaedah_pempolimeran_antaramuka.pdfPENCIRIAN MEMBRAN PENURASAN NANO YANG DIHASILKAN MENGGUNAKAN KAEDAH PEMPOLIMERAN ANTARAMUKA
ABSTRACT: Nanofiltration membrane (NF) is a type of membrane with properties in between ultrafiltration (UF) and reverse osmosis (RO). Its application is rapidly growing in water treatment for removal of various salts and organic solu tes. In this paper, three different NF membranes were fabricated using interfacial polymerisation technique to study the variation in their nanofiltrat ion properties as the dipping time during t he interfacial reaction was varied . The membrane support was made from mixture of polysulfone (PSF) and polyvinylpyrrol idone (PVP) with N-methyl-2-pyrrolidinone (NMP) as the solvent. The top active layer was obtained through interfacial polymerisat ion between trimesoyl chloride (TMC) in hexane with aqueous phase containing Bisphenol A (BPA). The three membranes differ in their dipping time during t he interfacial reaction. The performance of the membranes were then tested w ith distilled water, NaCl and Na2S04 . By using the Teorell -Meyer-Sievers (TMS) model , which is based on the extended Nernst Planck equation , the membrane characteristics, namely effective charge density, ratio of thickness over porosity and effective pore radius, were obtained. It was found that different membrane characteristics can be obtained with the variation in dipping time . KEYWORDS: Nanofiltration, interfacial polymerisation, characteristics , TMS model Author: A. Wahab Mohammad, Mazrul Nizam Abu Seman dan A. Amir H. Kadhum
Year: 2002
measurement_of_pipe_diameters_from_partial_2-d_images_using_moire_method.pdfMEASUREMENT OF PIPE DIAMETERS FROM PARTIAL 2-D IMAGES USING MOIRE METHOD
ABSTRACT: This paper proposes two techniques for finding the diameters of partially visible pipes based on the shapes of the visible portion of the surface as seen through a fixed-size window. In one method, vertical stripes are projected onto horizontally positioned cylinders in a simulation study. The lateral offset of the shadow of the individual stripes on the cylinder measured from a fixed distance from the axis is used as the parameter (known as variable x P) for finding the diameter. In the second method, simulated moire fringes were generated onto the surface based on the shadow moire concept and the distance between the second moire fringes, measured symmetrically from the center, is used as the input parameter (known as variable j P). When the pipe diameter varied by 2 mm, Xp varied by only 0.1 mm whereas jp varied by 1.0 mm. The second method is therefore more sensitive to variations in pipe diameters and, hence, less sensitive to errors. The simulated moire fringes were then compared to experimentally obtained fringes for a pipe of diameter 56 mm. The error in jp was found to be less than 5% . This verified that simulated data could be used to determine actual pipe diameters based on the moire fringe spacing. Our results showed that the diameter of the actual pipes could be determined to within an accuracy of ±2% using the proposed method. KEYWORDS: Diameter measurement, 2-D image, moiré method Author: Mani Maran Ratnam, Khor Ai Ni
Year: 2002
finite_element_analysis_for_design_and_structural_studies_of_a_polymeric-based_composite_automotive_pedal_box_system.pdfFINITE ELEMENT ANALYSIS FOR DESIGN AND STRUCTURAL STUDIES OF A POLYMERIC-BASED COMPOSITE AUTOMOTIVE PEDAL BOX SYSTEM
ABSTRACT: The goal of this study is to develop a design system for an automotive pedal box from polymer-based composites, in order to reduce both vehicle weight and manufacturing costs. Finite element analysis (FEA) is used in the design to carry out structural analysis of a polymeric-based composite pedal box system. Algor software is used for analysing and validating the design. Stress analysis and displacement results are used to confirm the pedal ribbing pattern. It is concluded that X ribbing pattern is more feasible to use in pedal levers and the calculated yield stress values for pedal components are acceptable. KEYWORDS: Finite element analysis (FEA), pedal box system, polymer-matrix composites (PMC), short-fibre composites Author: S.M. Sapuan, A. Lees and Z. Leman
Year: 2002
design_of_a_mini-uart_using_vhdl.pdfDESIGN OF A MINI-UART USING VHDL
ABSTRACT: This paper presents the design of a mini-universal asynchronous receiver and transmitter (UART) using very high-speed integrated circuit (IC) hardware description language (VHDL). The design is compiled and simulated under Altera MAXPLUS-11 EDA (Electronic design automation) Software environment and is implemented using Altera FPGA (Field programmable gate array) technology. Hardware verification results using oscilloscope are also presented. Simulation results of the transmitter and receiver modules of the UART show that it is functioning properly in serial data communication. Logic levels of the signals in the hardware verification results verify the simulation results and ensure the accuracy of the design. Due to modularity feature and compact size of the proposed UART, it is ideal for system-on-a-chip (SOC) application. KEYWORDS: UART, VHDL, FPGA, SOC Author: Liakot Ali, Roslina Sidek, Ishak Aris Mohd. Alauddin Mohd. Ali and Bambang Sunaryo Suparjo
Year: 2002