Skip Navigation LinksVolume : Volume 9 No.2 2000

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structure_and_properties_of_cellular_polypropylene_natural_rubber_blends_compatibilised_with_bismaleimide.pdfStructure and Properties of Cellular Polypropylene Natural Rubber Blends Compatibilised with Bismaleimide
ABSTRACT: Cellular polypropylene/natural rubber (PP/NR) blends compatibilised with N, N-m-phenylenebismaleimide (HVA-2) has been prepared by melt blending in a twin screw compounder followed by compression moulding, using modified Azodicarbonamide as the chemical blowing agent (CBA). Blends with different cell structures were obtained by varying the percentage of HVA-2 and CBA used and the influence of cell size and void fraction on the density, failure impact energy and damping factor of the cellular PP/ NR blends were investigated. In this study, a blend system with 0.5% HVA-2 and 2.5% CBA was observed from the SEM micrographs to have the smallest average cell size of 260 µm and the highest void fraction of 60% resulting in the greatest reduction in the apparent density as compared to the unfoamed PP/NR blend. The failure energy of the cellular PP/NR blends during impact, investigated using an instrumenied falling weight impact tester were found to increase with an increase in the void fractions and was at its maximum value at an optimum cell size of 350 µm. The damping factor (tan o) of the blends, determined using a Dynamic Mechanical Analyser, was found to increase with increasing void fraction and decreased with increasing cell size. AUTHOR: Hanim Harun, Zarina Rasmin, M.Y. Ahmad Fuad and Ismail Zainol
Year: 2000
optimisation_of_multi-stage_production-inspection_stations_using_genetic_algorithm.pdfOptimisation of Multi-stage Production-Inspection Stations Using Genetic Algorithm
ABSTRACT : The optimal allocation and sequencing of inspection stations is to be presented in this paper. The notion of optimality in this case encompasses factors such as the cost of inspection, the cost of allowing a defective unit to be output, and the cost of internal failure. The main goal of this work is to develop an efficient optimisation tool which will minimise the cost functions of the stated optimisation problems. The optimisation tool to be considered is Genetic Algorithm (GA). An introduction to the concepts of the GA and its encoding of the solutions to the problems in a genetic form and the evaluation of the resulting genetic code to give the fitness of those solutions will be discussed. The setting of the parameters for the genetic operators and the ways of initialising the solution population are also described. Finally, the results obtained are presented and compared to those produced by conventional methods. AUTHOR: Azmi Hassan, D.T. Pham
Year: 2000
mutiphase_oscillatory_flow_in_a_baffled_tube.pdfMULTIPHASE OSCILLATORY FLOW IN A BAFF
ABSTRACT: Hydrodynamics behaviour of multiphase oscillatory flow in a baffled tube was investigated. A CFD simulation of an oscillatory liquid flow in a baffled tube is carried out to determine the extent of its mixing capability prior to the actual laboratory work.The results of the CFD simulation show that efficient mixing is achieved in the space between baffles at low oscillatory Reynolds number corresponding to low oscillation frequencies. The application of oscillatory flow in a baffled tube for multiphase mixing is studied in this work. Oscillatory flow in a baffle tube is able to suspend solid up to 20% by weight of the column content. The mass fraction of solid in suspension increases ith oscillation velocity and liquid viscosity. The combined effect of oscillatory flow and gas fluidisation on solid suspension is also investigated in this work. The results shows that greater mass fraction of solid is suspended under this condition. AUTHOR: Mohd Sobri Takriff, Wan Ramli Wan Daud, Zahedi Fisal and Zahangir Alam
Year: 2000
integrating_knowledge-based_system_with_geometric_data_for_site_layout_planning.pdfINTEGRATING KNOWLEDGE-BASED SYSTEM WITH GEOMETRIC DATA FOR SITE LAYOUT PLANNING
ABSTRACT: The site layout is a complex process, requiring the analysis of large amounts of information from several disciplines (such as design, construction planning, estimating and others). It involves identifying, allocating and positioning temporary facilities (TFs), plant and materials, to best suit the needs of the construction process at each stage of construction. This paper describes the proposed algorithms used in the development of lnteSite (Intelligent Site Layout Planning) that has resulted in the implementation of a system that embodies the intuitive responses, judgements and experience of experts in its knowledge-base. Geometric information from CAD system is automatically mapped into knowledge-base system at real time for optimising site layout planning. AUTHOR: Mohamad Jamil Sulaiman
Year: 2000
ABSTRACT: An aromatic vinyl monomer was successfully grafted onto a commercial isotactic polypropylene (PP) by the use of an organic peroxide. An aliphatic peroxide, 2,5-dimethyl-2,5-di-t-butylperoxy hexane, was employed in the grafting reactions that were carried out for 10 minutes in melt at 180°C. The grafting reaction was confirmed through FTIR spectra showing infrared bands which conformed to aromatic substi.tuted benzene in the grafted copolymer, while weight percentage of monomer grafted to polypropylene and percentage grafting of monomer were obtained through the measurements of infrared absorbance bands of grafted polymer at two different peaks (752 cm-1 and 690 cm-1), before and after extraction. These values were found to be agreeable and consistent. Influence on the thermal properties was also investigated, where DSC melting curves showed the formation of double melting peaks. Effects of initiator and monomer concentration on the melting peaks and crystallinity of the grafted polypropylene were also reported. AUTHOR: S. J. Syed Mustafa, M. R. Nor Azlan, M.Y. Ahmad Fuad, Z.A. Mohd lshak and U.S. lshiaku
Year: 2000
effect_of_lubricant_on_the_porosity_of_bronze_cu-sn_based.pdfEFFECT OF LUBRICANT ON THE POROSITY OF BRONZE (CU-SN) BASED
ABSTRACT: Porosity is one of the most important parameters influencing the performance of self-lubricating bearing. The effect of lubricant on the porosity of Cu-Sn based self-lubricating bearing was investigated. Zinc stearate (ZnS) and lithium stearate (LiS) were used as lubricants. Results indicated that dimension of pores on Cu-Sn-LiS were slightly bigger while interconnected porosity and percentage of pores were slightly higher than of Cu-Sn-ZnS. Cu-Sn-LiS formed branching pores with irregular boundaries. Consequently, Cu-Sn-ZnS formed less branching pores with rounded boundaries. Hence, lubricant does effect the porosity of Cu-Sn system.
Year: 2000
concentrated_laundry_powder_detergent.pdfCONCENTRATED LAUNDRY POWDER DETERGENT
ABSTRACT: The most recent change in detergent powder technology has been the move from conventional to concentrated (compact) laundry powder detergent. This article reviews the types of laundry detergent in existence today, their consumption, typical composition and the process to manufacture concentrated laundry powder detergent
Year: 2000