Nik Hisyamudin Muhd Nor

Effect of Velocity on the Impact Resistance of Woven Jute Fiber Reinforced Composites

is present project investigated the impact penetration response of woven jute fiber reinforced composites subjected to wide range of low impact velocities. Hand layout woven jute fibers are thermally compressed to ensure no internal defects formed in the composites. Six layers of woven jutes are stacked together using different fiber orientations [0/q/0]s. Low impact velocities are used ranging between 5 – 20 m/s. Force-time, force-displacement and energy-time curves are obtained automatically during the impact tests. The results are then discussed with considering the composite fragmentations and failure mechanisms. It is found that 00 composite orientations capable to absorb sufficiently impact energy for 5 m/s but not for velocity greater than 10 m/s. When fiber orientations used between 15 – 450, the composite impact resistance increased indicating two significant peak forces. These peak forces represent different type of failure mechanisms occurred during the striker progresses.

Decision Making With the Analytical Hierarchy Process (AHP) for Material Selection in Screw Manufacturing for Minimizing Environmental Impacts

This study is an approach to investigate the environmental impact of screw manufacturing and to choose suitable material for selected screw-making processes for the best performance with minimum environmental impact. The parameters involved were types of material and screw-making process using the environmental data available in Asia region. The two different manufacturing approaches being evaluated were machining and forging. The types of material considered were low carbon steel, stainless steel, titanium alloy and aluminium alloy. As for machining process, the materials being considered in screw manufacturing were low carbon steel, stainless steel, titanium alloy, aluminium alloy, magnesium alloy and cast iron. The information of environmental impact are generated by SolidWorks. Sustainability tool was used in the formation of pair-wise comparison matrices for Analytic Hierarchy Process (AHP). Then, the ranking of global priorities had enabled the determination of appropriate material to be used for those selected screw manufacturing process. As a result, aluminium alloy was found to give minimum environmental impact for forging process whereas cast iron was found to excel in machining process. At the same time, titanium alloy was not suggested to be used in either process.

Taguchi design and flower pollination algorithm application to optimize the shrinkage of triaxial porcelain containing palm oil fuel ash

In the preparation of triaxial porcelain from Palm Oil Fuel Ash (POFA), a new parameter variable must be determined. The parameters involved are the particle size of POFA, percentage of POFA in triaxial porcelain composition, moulding pressure, sintering temperature and soaking time. Meanwhile, the shrinkage is the dependent variable. The optimization process was investigated using a hybrid Taguchi design and flower pollination algorithm (FPA). The interaction model of shrinkage was derived from regression analysis and found that the shrinkage is highly dependent on the sintering temperature followed by POFA composition, moulding pressure, POFA particle size and soaking time. The interaction between sintering temperature and soaking time highly affects the shrinkage. From the FPA process, targeted shrinkage approaching zero values were predicted for 142 μm particle sizes of POFA, 22.5 wt% of POFA, 3.4 tonne moulding pressure, 948.5 °C sintering temperature and 264 minutes soaking time.

Cyclic voltammetry measurement for n-type Cu2O thin film using copper sulphate-based solution

Cuprous oxide (Cu2O) is a promising material for solar cell application. Due to its various advantages over silicon material, it has been exploited extensively to be use in photovoltaic cell. Cu2O thin films were electrodeposited in sulfate-based solution. Cyclic voltammorgram (CV) measurement was used to investigate the reduction process under controlled parameters. Deposition potential of-0.1V vs. Ag/AgCl was used for the fabrication of Cu2O thin film based on the CV measurement. CV also revealed that the deposition speed was dependent on the bath pH and the temperature. X-ray diffraction (XRD) measurement, Field Emission Scanning-Electron Microscopy (FE-SEM) and Ultraviolet-visible spectroscopy (UV-Vis) were performed to characterize the deposited thin films. The n-Cu2O was successfully fabricated on FTO glass substrate with (111)-prefered orientation. Surface morphology of the thin films were observed to be in flower-like shape combination with pyramidal and triangular shape.

Optimization of the EMI shielding effectiveness of fine and ultrafine POFA powder mix with OPC powder using Flower Pollination Algorithm

In order to solve the electromagnetic interference (EMI) issue and provide a new application for palm oil fuel ash (POFA), POFA was used as the cement filler for enhancing the EMI absorption of cement-based composites. POFA was refined by using water precipitation for 24 hours to remove the filthiness and distinguish the layer 1 (floated) and layer 2 (sink) of POFA. Both layers POFA were dried for 24 hours at 100 ± 5 °C and grind separately for sieve at 140 μm (Fine) and 45 цш sizes (Ultrafine). The micro structure and element content of the both layers POFA were characterized by scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) respectively. The results showed layer 1 POFA has potentialities for EMI shielding effectiveness (SE) due to its higher carbon content and porous structure. The study reveals that EMI SE also influenced by the particle size of POFA, where smaller particle size can increase 5 % to 13 % of EMI SE. When the specimen consists of 50% POFA with passing through 45 μm sieve, the EMI was shield -13.08 dB in between 50 MHz to 2 GHz range. Flower Pollination Algorithm (FPA) proves that POFA passing 45 μm sieve with 50% mixed to OPC is optimal parameter. The error between experimental and FPA simulation data is below 1.2 for both layers POFA.

Storage of CO2 in Low Al2O3 EAF Oxidizing Slag by Grinding with Vibration Mill

The investigation of the behavior of CO2 absorption into the low Al2O3 electric arc furnace (EAF) oxidizing slag under wet grinding was investigated in this paper. The slag was wet ground in the vibration ball mill in the presence of CO2 at room temperature. The observation of the CO2 absorption was made with constant pressure method. The CO2 absorption increased steeply in the early stage of grinding. It occurred simultaneously with the grinding and immediately ceased when the grinding was stopped. The CO2 absorption occurred at the interface between the slag and the water which was saturated with CO2. The CO2 absorption increased as the finer particles were formed by the grinding process, and as the interface between slag and water was increased by the vibration process. A large amount of CO2 absorption and high conversion ratio was observed in the oxidizing slag with low Al2O3 in comparison with those of the slag with the high Al2O3 content.

Growth Mechanism of Copper Oxide Fabricaticated by Potentiostatic Electrodeposition Method

This experiment is about fabrication of n-type Cu2O thin film on fluorine doped thin oxide (FTO) glass by using copper acetate based solution through potentiostaticelectrodeposition. A range of deposition time was carried out from 20 to 40 minutes and the results were obtained. The other parameters such as potential deposition, bath temperature and pH value of solution were kept constant for-0.125Vvs Ag/AgCl, 60 °C and pH 6.3, respectively. It was found that the optimum deposition time for growth mechanism of n-type Cu2O thin film was 30 minutes. Structural, morphologicaland optical properties were characterized by using X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), and Ultraviolet and visible Absorption Spectroscopy (UV-Vis), respectively. The successfully fabrication of n-Cu2O was confirmed using PEC measurement result.

Reaction between Carbon Dioxide and Mechanically Activated Metal Powder

A fundamental study on the reaction between CO2 and mechanically activated metal powders has been conducted. In this research, the behavior and mechanism of CO2 reaction under various grinding conditions were investigated to fix and reduce CO2. The powder used was placed inside a grinding vessel, and was ground together with the SUJ2 balls in CO2 atmosphere. It was found that only the adsorption of CO2 gas on the ground samples was observed, whereas the decomposition of CO2 was not occurred. The CO2 adsorption increased proportionally with the increase in the grinding speed, weight of sample and number of SUJ2 balls. Furthermore, the CO2 adsorption increased with the decrease in the standard free energy of formation of each metal oxide. The morphology of the sample observed by SEM showed that the samples were not crushed into finer particles, but were only grazed on the sample’s surface. Therefore, it can be said that the CO2 can be adsorbed on the mechanically activated samples by using the centrifugal type ball mill, but in order to enhance the amount of CO2 adsorption, another type of machine with higher grinding intensity should be considered.

Solubility of Nitrogen Gas into Molten Copper at Temperature Range of 1,993 K to 2,443 K

Abstract Solubility of nitrogen gas into pure copper at temperature range of 1,993–2,443 K was studied with using a levitation melting apparatus. The solubility which was dissolved content of nitrogen equilibrated with nitrogen gas with a pressure of 101.3 kPa increased with the temperature of molten copper. However, the solubility was approximately 1.5 mass ppm even at 2,443 K. Absorption of nitrogen gas into pure copper obeyed the Sieverts’ law and was expressed as: 12N2gas=N_