Skip Navigation LinksVolume : Volume 1 No.1 1991

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the_influence_of_holding_time_on_the_properties_of_ductile_iron.pdfTHE INFLUENCE OF HOLDING TIME ON THE PROPERTIES OF DUCTILE IRON
ABSTRACT: This paper describes factors that influence the effectiveness of inoculating molten iron to form spt,eroidal graphite. The study shows .how the process parameters uch as · holding time and chemical composition affect the mechanical properties and metallographic behaviour of the alloys. A high initial residual Mg in the molten iron results in a more rapid decrease In the Mg content. As holding time increases, holding temperature, pearlite structure and hardness. of the ductile iron d~creases. Carbide formation increases if the dross is not removed from the ductile iron. Finally, ductile molten iron should not be poured at temperatures lower than 1380°C as shrinkage defects are likely to occur. AUTHOR: Mohd. Akhir Yeop Kamaruddin
Year: 1991
production_of_cocoa_butter-like_fats_from_palm_oil_by_enzymatic_interesterification.pdfPRODUCTION OF COCOA BUTTER-LIKE FATS FROM PALM OIL BY ENZVMATIC INTERESTERIFICATION
ABSTRACT: Lipase-catalysed incorporation of stearic acid Into three RBD palm oil fractions - palm oil, palm stearin and palm olein - by the 1,3-regiospecific Novo lipase Lipozyme IM20 produced a complex mixture of fatty acid glycerides and free fatty acids. Stearoyl Incorporation resulted In 40-50% of the desired cocoa butter-like triglycerides In the fatty acid glyceride portion, namely distearoyloleoyl-glycerol, palmitoyl-oleoyl-stearoyl-glycerol and dipalmitoyl-oleoyl-glycerol. In the fractionation of lnteresterified palm olein, free fatty acids were removed from the product mixture by steam distillation under vacuum followed by fractional crystallisation of the fatty acid-free glycerides In hexane and/or acetone. This procedure gave cocoa butter-like fats with triglyceride and melting profiles comparable to that of cocoa butter as adduced by reversed phase high performance liquid chromatography (HPLC) and differential scanning calorimetry (DSC), respectively. The yields of the cocoa butter-like fats ranged from 26-32% of the weight of the interesterified oil, depending on the crystallisation procedures adopted. AUTHOR: C.N. Chong, Y.M. Hoh, C.W. Wang & C.K.Ooi
Year: 1991
optimising_methane_yield_in_anaerobic_pome_treatment_through_temperature_and_process_manipulations.pdfOPTIMISING METHANE YIELD IN ANAEROBIC POME TREATMENT THROUGH TEMPERATURE AND PROCESS MANIPULATIONS
ABSTRACT: A model predicting the steady-state digestion temperature, based on a heat energy balance, of an influent-heated anaerobic reactor was developed. The heat transfer study on four full-scale anaerobic reactors treating POME revealed that the overall heat transfer coefficient was 7. 7 ±. 1.1 x 102 kJ/m²/K/day or 8.9 ±. 1.3 W/m²/K. The model was tested on two reactors and showed substantial agreement with the observed data. A comparative study of the conventional and contact processes at an industrial scale.concluded that there was considerable enhancement of methane yield In the latter. Existing conventional digesters could be easily modified and manipulated to operate on the contact process. The said model, coupled with these and other findings, could be used to derive practical design parameters for optimising methane yield and reactor performance in the anaerobic treatment of organic industrial wastewaters. KEYWORDS : Anaerobic wastewater treatment-methane yield-heat transfer analysis-modelling-thermophilic anaerobic contact process-palm oil mill effluent-biomass energy utilisation. AUTHOR: B.G. Yeoh*, M.Y. Rosian & S.K. Quah
Year: 1991
application_of_knowledge-based_system_in_process_planning.pdfAPPLICATION OF KNOWLEDGE-BASED SYSTEM IN PROCESS PLANNING
ABSTRACT: Knowledge-based System (KBS) or commonly called Expert Systems is a branch of Artificial I ntelllgence which is receiving increased attention in the manufacturing area. This article gives an overview of the application of KBS In process planning. A prototype knowledge-based system, TURN PLANNER is described to demonstrate the benefits of using KBS in process planning. Expert knowledge on the machining process is stored as a knowledge base in the form of rules; Using a part description method and databases, the system has shown to be capable of generating useful process plan data for machining of rotational parts. Although still at its developmental stage, test results show that process plans produced using a TURN PLANNER are more accurate, consistent and have reduced planning times, compared to the manual methods. KEYWORDS : Knowledge-based systems-expert systems-computer-aided process planning-turning-features-operation sequence. AUTHOR: Wan Abdul Rahman Wan Harun
Year: 1991