Saparudin Ariffin

Mechanical Properties Evaluation of Woven Coir and Kevlar Reinforced Epoxy Composites

The utilization of coconut fibers as reinforcement in polymer composites has been increase significantly due to their low cost and high specification of mechanical properties. Whereas kevlar fibers has widely used as the core material in flexible body armors due to its great mechanical properties, such as high strength, light weight, good chemical resistance and thermal stability. The research work is concerned with the evaluation of high speed impact and flexural test of hybrid textile reinforced epoxy composites. Samples were prepared from coir yarn, kevlar yarn, interlaced of coir and kevlar yarn with different warp/weft orientation and pure epoxy as control specimen. The woven samples were produced using handloom and the composites specimens were prepared using hand lay-up technique. From the results obtained, it was found that woven kevlar composites samples displayed the highest impact properties while it exhibits the lowest flexural properties. Results also showed that the composite plate for woven coir yarn (warp) and kevlar yarn (weft) has the flexural strength and impact strength of 17 MPa and 67 kJ/m², which presented as the nearest properties to woven Kevlar composite respectively. These results indicate that coir as a natural fiber can be used as a potential reinforcing material for high impact resistance such as body armors in order to reduce the usage of synthetic materials whilst utilizing the natural resources.

Finite scheduling of collaborative design and manufacturing activity: a Petri net approach

Purpose – This paper aims to present an approach of utilizing Petri net (PN) to model and schedule collaborative design and manufacturing activities at a cyber manufacturing centre (CMC).Design/methodology/approach – A conceptual PN model consisting of all activities at the CMC is drafted. This model is then simplified to generate a conflict free PN for scheduling analysis purposes. Based on this simplified PN, generalized scheduling algorithms were developed. The algorithms were used in spreadsheets to process and analyze the operation database before finally transforming it into a dynamic finite scheduling sequence in the form of Gantt chart.Findings – The PN is found to be very useful in modelling and analysing the scheduling sequence for a CMC with collaborative activities resembling flow shop with shared resources.Originality/value – The models and methods described in this paper are practical means of utilizing PN in managing the scheduling and manufacturing activities.

Mercerization Treatment Conditions Effects on Kenaf Fiber Bundles Mean Diameter Variability

The interest in utilizing natural fiber as reinforce in polymer composites has increased in recent years due to their advantages like availability, cheap, renewable, lightweight, and biodegradable. However, the main challenge of natural fiber to be used as reinforcement in polymer is their hydrophobic nature. One of the solutions is via chemical modification like mercerization treatment. In this study, the effect of alkali concentrations at 2 and 10 w/v %; and soaking temperature at 30°C and 80°C on a kenaf fiber bundles mean diameter was investigated. Untreated kenaf fiber was used as a control unit. Kenaf fiber diameter was measured using a Leica video analyzer. Microstructure change of kenaf fiber before and after mercerization treatment conditions was identified using JOEL scanning electron microscopy (SEM). Finally, an interaction of alkali treatment conditions on kenaf fiber bundles mean diameter value was statistically analyzed using a commercially available statistical software package. The results showed that kenaf fiber bundle mean diameter was reduced by 30.12% to 42.92% after mercerization treatment. From analysis of variance, the main effect of alkali concentration value was 6.075 and the temperature value was 1.135. The main effect plots reveal that alkali concentration had a higher impact on mean diameter changes compared to soaking temperature factor.

The Effect of Pretreatment Powder Using Ball Mill and Ultrasound on the Properties of Single Cell Solid Oxide Fuel Cell

Solid oxide fuel cell (SOFC) is currently popular due to its capability to convert hydrogen into electricity directly from oxidizing hydrogen fuel. The SOFC is one of the expected renewable energy devices and green technology in the future because of less carbon dioxide production and no pollutant product. Performance of SOFC was influenced by morphology and microstructure of the material, starting particle size and particles distribution. This paper addresses the comparative evaluation of using pretreatment NiO/YSZ powder using ball mill and ultrasound processess on the performance of a single cell SOFC. The performance of solid oxide fuel cell was evaluated using scanning electron microscopy (SEM), X-Ray diffraction (XRD) and impedance spectroscopy, measured at room temperature. The results indicate that the treatment using ultrasound process is better than ball mill process due the total resistance is smaller and distribution particle is more homogenous.

Impact of alkali treatment conditions on kenaf fiber polyester composite tensile strength

The increase of environmental issues awareness has accelerated the utilization of renewable resources like plant fiber to be used as reinforced material in polymer composite. However, there are significant problems of compatibility between the fiber and the matrix due to weakness in the interfacial adhesion of the natural fiber with the synthetic matrices. One of the solutions to overcome this problem is using chemical modification like alkali treatment. In this study, the impact of alkali treatment conditions on short randomly oriented kenaf fiber reinforced polyester matrix composite tensile strength was investigated. The experimental design setting was based on 2 level factorial experiments. Two parameters were selected during alkali treatment process which are kenaf fiber immersion duration (at 30 minute and 480 minute) and alkali solution temperature (at 40°C and 80°C). Alkali concentration was fixed at 2% (w/v) and the kenaf polyester volume fraction ratio was 10:90. The composite specimens were tested to determine the tensile properties according to ASTM D638-10 Type I. JOEL scanning electron microscopy (SEM) was used to study the microstructure of the material. The result showed that alkali treatment conditions setting do have the impact on tensile strength of short randomly oriented kenaf polyester composite. The interaction factors between immersion time and temperature was found to have prominent factors to the tensile strength of composite followed by the immersion time factor.

Analysis of single phase flow pressure drop and heat transfer in a horizontal rifled tube

Analysis by using Fluent® has been carried out to investigate the pressure drop and heat transfer of single phase flow (Reynolds number ranging from 2.0×104 − 1.4×105) in a 2 meter long of rifled tube and smooth tube which are heated at the outer wall at constant temperature. The rifled tube or also known as spiral internally ribbed tube which is used in this investigation has an outside diameter 45.0 mm and inside equivalent diameter of 33.1 mm while the smooth tube has an outside diameter 45.0 mm and inside diameter 34.1 mm. The working fluid that is used in this investigation is water. In this analysis, realizable k-epsilon model has been chosen to solve the fully developed turbulence flow in both the tubes. The result from simulation shows that the pressure drop in rifled tube is about 1.69-2.0 times higher than in the smooth tube while the heat transfer coefficient of water in the rifle tube is 0.97-1.27 times than in the smooth tube. The high pressure drop and heat transfer coefficient in rifled tub...

Numerical Analysis of Single Phase Flow Pressure Drop in a Horizontal Rifled Tube

Numerical analysis by using Fluent® has been carried out to investigate the pressure drop of single phase flow in a 2 meter long of rifled tube and smooth tube which is placed horizontally. The rifled tube or also known as spiral internally ribbed tube that is used in this investigation has an outside diameter 45.0 mm and inside equivalent diameter1 of 33.1 mm while the smooth tube has an outside diameter 45.0 mm and inside diameter 34.1 mm. The working fluid that is used in this investigation is water. In this numerical analysis, realizable k-epsilon model has been chosen to solve the fully developed turbulence flow in both the tubes. The result of the pressure drop which is obtained from simulation shows that the pressure drop in rifled tube is about 1.69-1.77 times much higher than pressure drop in smooth tube. The high pressure drop in rifled tube comparing to smooth tube is due to the helical rib in the rifled tube which causes swirling effect near the wall. A correlation has been proposed for the single phase friction factor of the rifled tube.

Development of Clay Thin Plate as First Preparation for Solid Oxide Fuel Cell Manufacture—Preliminary Study

Various methods have heen implemented to manufacture the intermediate temperature solid oxide fuel cell. The quality of thin plate fuel cell that allows the optimum electrons flow within the fuel cell membrane is of interest. This paper investigates the manufacturing process of clay thin plate for solid oxide fuel cell (SOFC) using the compaction method. Several parameter processes that affect the quality of thin plate such as compaction loading, microstructure and deformation of thin plate at green density and after sintering are investigated. The thin plate is fabricated from clay powder using a single acting compaction at a finite loading, for sintering temperature at about 1350° C with holding time of 30 minutes. The thin plate is underwent a scanning process using a Scanning Electron Microscopy to evaluate the grain size and thickness plate. The result indicates the substantial information of parameter process of clay thin plate for solid oxide fuel cell manufacture.

Mechanical Properties of Clay Thin Plate as Pre‐Evaluation for Solid Oxide Fuel Cell Manufacture

Solid oxide fuel cell that produces a certain power density requires specific air pressures to be flowed within its membrane to ensure that certain electrons flow through its fuel cell membrane. Therefore, it is vital for a fuel cell membrane to sustain the pressure loading without any failures. This paper investigates the mechanical properties of clay thin plate as a preliminary evaluation of parameter processes used for solid oxide fuel cell manufacture. Several parameter processes that affect the mechanical properties such as compaction loading, sintering temperature, grain size and of the thin plate are of interest. The experiment uses the Vickers test to determine the hardness number. The experimental results are used as guidance in preparing the thin plate of solid oxide fuel cell.