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