Skip Navigation LinksVolume : Volume 1 No.1 1991

  
  
  
Count= 4
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