Skip Navigation LinksVolume : Volume 22 No.1 2014

  
  
  
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paper_70.pdfADDITIVE INFLUENCE ON GASIFICATION OF PALM OIL EMPTY FRUIT BUNCH PELLET
  
ABSTRACT:  
In this research, a gasification experiment using Empty Fruit Bunch (EFB) pellets was carried out in Rosenheim, Germany, using a fully functioned gasification plant developed and owned by Stadtwerke Rosenheim. The research was conducted with a mixture of spruce wood chip and EFB. This is because EFB has high ash content and to reduce the total ash in the feedstock, spruce wood was mixed. . In addition the softening point of ash from EFB is low which will likely have an agglomeration issue at high temperature. The research was conducted in 2 different mixtures which include 33 % EFB and 67 % wood chip and 33 % EFB and 67 % wood chip with addition of additive. The additive was added to reduce the ash potassium content and increase its softening point. Gasification without additive did not manage to run in long hours as agglomeration built up in the reactor while with additive, the gasification managed to run for about 10 hours with 2.98 m3/kg of gas yield, cold gas efficiency recorded at 83.31 % and the calorific value of the feed stock mixture is 5.30 MJ/m³, comparable to gasification with 100 % of wood chips. Therefore a suitable gasification design has to be explored in the future considering the properties of EFB. Apart from the gasification reactor, pelletizing of EFB has to be premixed with additive in order to enable the EFB to be gasified at high temperature to enable the productionof a quality gas without a risk of agglomerations.     



KEYWORDS: Gasification, Empty Fruit Bunch (EFB), additive, agglomeration, sintering, EFB treatment.     

Author: Mohd Nizam Mokhri, Horst Kreimes, Reinhold Egeler, Chen Sau Soon
Year: 2014
paper_6.pdfSTUDY OF FEEDSTOCK PREPARATION AND DEBINDING PROCESS OF INJECTION MOULDED HIP STEM Co-Cr-Mo ALLOY POWDER USING WAX-BASED BINDER
  
ABSTRACT:
Metal Injection Moulding (MIM) has undergone development of various binder systems with the aims of shortening the overall debinding time duration. In this work, the binder system based on wax has been utilised in injection moulding of hip stem using CoCrMo alloy powder. The feedstock consisted of Co-Cr-Mo powder with mean diameter particle size of 16µm and binder which comprised of paraffin wax, polyethylene and stearic acid. The moulded hip stem was immersed in n-heptane at 60°C in order to remove the paraffin wax and stearic acid. Results showed that solvent extraction debinding technique allowed complete removal of the paraffin wax and stearic acid from the injection moulded hip stem within 4 hours, without swelling or distortion of the debound part. Scanning Electron Microscopy (SEM) observations have shown that large pores were formed from the surface to the interior of the debound part during the processes. In addition, this technique was found to be suitable to shorten the debinding time, which consequently resulted in a debound part that possesses adequate strength for handling.



KEYWORDS: CoCrMo, MIM, wax, debinding,

Author: M.A.Omar, N.Abdullah, R.Sayuti, F. Ismail, N.Zainon, and Baharuddin, M.Y.
Year: 2014
paper_50.pdfFABRICATION OF 45S5 BIOGLASS? COMPOSITE SCAFFOLD
  
ABSTRACT:
Recently, osteochondral tissue engineering have attracted great attention because a variety of diseases such as osteoarthritis. Expands in this tissue engineering, it has led researches to approach a new device such as a 45S5 Bioglass® composite scaffold as interfacial tissue, which will be implanted between cartilage and tibia at knee site. The composition of 45S5 Bioglass® composite are 45% SiO2, 24.5% Na2O, 24.5% CaO and 6% P2O5. This paper will describe the fabrication of 45S5 Bioglass® composite scaffolds which will be the layer for bone growth in the constructs for osteochondral tissue engineering. The fabrication of 45S5 Bioglass® scaffold was carried out using foam replication technique which consists of two steps; (1) preparation of green body and (2) sintering of 45S5 Bioglass® scaffold. Characterisations of the above scaffold were carried out using Variable Pressure Scanning Electron Microscope (VPSEM), INSTRON Universal Tensile Machine (UTM) and X-ray diffraction (XRD). The SEM micrographs revealed the porous structure of the scaffold consisting of micropores and nanopores. The X-ray diffraction (XRD) spectrum showed the presence of Na2Ca2Si3O9 phases in the sintered scaffold. 45S5 Bioglass® scaffold sintered at 1000°C for 2 hours gave the compressive strength of 0.32 MPa. Bioactivity assessment in Simulated Body Fluid (SBF) for 7, 14 and 28 days showed the formation of apatite layer on the scaffold.     



KEYWORDS: Green body, 45S5 Bioglass® scaffold, tissue engineering. 

Author: Suriani Shamsudin, Suhaida Mat Ghani, Sudirman Sahid, Wan Ruzaini Wan Sulaiman, Salina Sabudin, Darmawati Mohd Yunos
Year: 2014
paper_4_final_doll.pdfSYNTHETIC ANORTHITE CERAMIC FROM LOCAL RAW MATERIALS
  
ABSTRACT:    
Bone china together with soft porcelain and fine translucent china is grouped as a main commercial translucent whiteware. Translucent whitewares are dense, white and allow some light to pass through them. Soft porcelain and fine translucent china are made from a mixture of kaolin, feldspar and quartz, although they have a translucent body, their strength and fracture toughness are not very high as the glass content is higher. Bone china is stronger and tougher than other translucent wares because it is a crystalline material. The present work on synthetic anorthite (CaO.Al2O3.2SiO2) material or synthetic bone ash is designed to provide an alternative to natural bone ash materials. It is also designed to have equivalent properties of natural bone ash. The anorthite was prepared by calcining the low-iron containing materials, such as local calcium carbonate (CaCO3), silica (SiO2) and commercial aluminium trihydroxide (Al(OH)3) together with a little magnesium carbonate (MgCO3) as a fluxing agent. The synthesized anorthite materials contained about 90 % anorthite and 10 % corundum. Anorthite phase was formed as early as 1200 oC. The average density of the synthetic anorthite was 2.77 gcm-3 when sintered at 1240 oC to 1280 oC that was very close to the theoretical value of natural anorthite density of 2.76 gcm-3. The synthetic anorthite can be used as precursor material for ceramic products such as synthetic bone china.     


Keywords: Anorthite, synthetic bone ash, bone china     

Author: Doll Said Ngah
Year: 2014
paper_3.pdfBACTERIAL IDENTIFICATION OF PEPTOCOCCACEAE FAMILY BASED ON BERGEY’S MANUAL VIA ARTIFICIAL NEURAL NETWORK APPROACH
  
ABSTRACT:  
A novel technique employing a neural network system was used as a tool for identifying bacterial species from Peptococcaceae family.   The study was initiated by extracting the bacterial properties from the Bergey’s Manual and the data was then trained using neural network tool in MATLAB programme Version 7.0 (Math Works, U.S.) software. Standard parameters were involved during the development of the neural network system such as neuron numbers, activation function used and learning algorithm in a batch training mode. The results indicated that the developed neural network for the identification programme worked successfully with an accuracy of 92%. The application of large neuron numbers in the hidden layer for a large set of training data has improved the network prediction capabilities with high accuracy. Otherwise, small neuron numbers in the hidden layer were adequate for small and medium sets of training data. The accuracy of developed neural network system was compared with a conventional identification system of bacteriology tool, Microstation BIOLOG (MicroLog3 4.20.05), by conducting bacterial identification experiments on three Gram-Positive bacterial species’. The developed neural network system used much simpler steps and required much shorter time.     

Keywords: Bacterial Identification; Bergey’s Manual; Peptococcaceae;Neural Network     

Author: Normadyzah Ahmad, S. Rozaimah S. Abdullah, Nurina Anuar
Year: 2014
paper_2.pdfTHE EFFECT OF MOLECULAR WEIGHT AND CONCENTRATION OF HYPERBRANCHED POLYGLYCEROL FOR SOLUBILISING HYDROPHOBIC DRUGS
  
ABSTRACT:
A water soluble hyperbranched polyglycerol with p-nitrophenol core with five different molecular weights and four different concentrations of each polymer has been synthesised and characterised. Polyglycerol with p-nitrophenol core was synthesised using anionic ring opening polymerisation technique with glycidol as the monomer. Five different molecular weights of the hyperbranched polymer were produced  i.e 4000 Da, 8000 Da, 12500 Da, 25000 Da and 50000 Da. Four different concentration of each molecular weight of hyperbranched polyglycerol were also prepared which were 1.0 x 10-4 M, 2.0 x 10-4 M,  4.0 x 10-4 M  and 6.0 x 10-4 M. These hyperbranched polyglycerols were then used to solubilise hydrophobic molecules i.e. naphthalene and ibuprofen. Solubilisation of all molecules increased after encapsulation with the hyperbranched polyglycerol. The results showed that the solubilisation of naphthalene increased from 0.62 x 10-4 M to 2.33 x 10-4 M for hyperbranched polymer with molecular weight of 4000 Da to 50000 Da with concentration of 1.00 x 10-4 M. For ibuprofen, the solubilisation increased from 5.30 x 10-4 M to 12.88 x 10-4 M for hyperbranched polymer molecular weight of 4000 Da to 50000 Da with concentration of 1.00 x 10-4 M.

KEYWORDS: hyperbranched polymer, solubiliser, encapsulation   

Author: Suriani Shamsudin, Lance J. Twyman, Muhamad Fadhlullah Rahmat
Year: 2014
paper_1.pdfSINTERING BEHAVIOUR, MICROSTRUCTURE AND MECHANICAL PROPERTIES OF SUB-MICRON HARDMETALS POWDER PROCESSED IN NITROGEN-BASED ATMOSPHERE
  
ABSTRACT:
Cemented tungsten carbide (WC) insert is widely used for a variety of applications such as machining, cutting, drilling and others. The properties of this tungsten heavy alloy are sensitive to processing and degraded by residual porosity. The sequences of high-end Powder Metallurgy (PM) process include mixing and compacting, followed by multi-atmosphere sintering of green compact. The sub-micron (1.0 µm) and less than 10.0 µm of WC powders are sintered with a metal binder (6 wt.% Co) to provide pore-free part. The powder compacts were sintered at temperatures ranging from 1200-1550 ºC in nitrogen-based sintering atmosphere. To date, many works in the literature mentioned that the best sintering technique of tungsten carbide was carried out via liquid phase sintering mechanism in vacuumand pure hydrogen atmosphere at 1500 and 1485 ºC, respectively. However, from this study we found that in order to attain better mechanical properties, a fine grain size of powder is necessary and could be sintered in nitrogen-based atmosphere, too. Therefore, the attention of the current work is to develop and produce wear resistant component with better properties or comparable to the commercial ones.   

KEYWORDS:  Powder Metallurgy, tungsten carbide, liquid phase sintering, nitrogen-based atmosphere 

Author: M.A. Selamat, A.A. Mahaidin, S. Abdul Manaf and T. Ria Jaafar
Year: 2014