Sia Chee Kiong

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.

Carbon Sequestration and Carbon Capture and Storage (CCS) in Southeast Asia

Southeast Asia is a standout amongst the most presented districts to unnatural weather change dangers even they are not principle worldwide carbon dioxide (CO2) maker, its discharge will get to be significant if there is no move made. CO2 wellsprings of Southeast Asia are mainly by fossil fuel through era of power and warmth generation, and also transportation part. The endeavors taken by these nations can be ordered into administrative and local level. This paper review the potential for carbon catch and capacity (CCS) as a part of the environmental change moderation system for the Malaysian power area utilizing an innovation appraisal structure. The countrys recorded pattern of high dependence on fossil fuel for its power segment makes it a prime possibility for CCS reception. This issue leads to gradual increment of CO2 emission. It is evident from this evaluation that CCS can possibly assume a vital part in Malaysias environmental change moderation methodology gave that key criteria are fulfilled. With the reason to pick up considerations from all gatherings into the earnestness of an Earth-wide temperature boost issue in Southeast Asia, assume that more efficient measures can be taken to effectively accomplish CO2 diminishment target.

Feasibility Study of Waste Motor Recycling through Manual Dismantling and Hydrometallurgical Process

Huge amount of waste electrical and electronic equipments (WEEE) or electronic waste (E-waste) has been produced every year in the world. It consists of valuable and hazardous metals that can be reused or extracted to minimize the environmental impact. This study is focusing on the investigation of recycling potential of e-waste through manual dismantling process and leaching test. The leaching test was conducted by changing the initial pH with constant stirring speed, constant water-sample ratio and in open air. The morphological structures of the solid samples were observed by SEM and the liquid residue was analyzed by Atomic Absorption Spectroscopy (AAS). It was found that total time required to dismantle all parts in the waste motor is about 10 minutes and the part that required longest dismantling time was armature windings. The metal elements that were observed are Fe, Mg, Pb and Cr. It was found that the pH of the solution increased with the increasing leaching time. The dissolution of Fe and Pb was high in the early stage of leaching but gradually decreased afterward. The dissolution for Mg and Cr was low throughout the leaching process. It was revealed that the metal elements in e-waste can be dissolved using this method and further investigation to increase the dissolution rate is required to ensure that the method proposed is applicable in industry. However, dissolved concentration of Pb must be controlled to ensure that it follows the permissible amount set under environmental standard.

Decision Making of Screw Manufacturing for the Best Environmental and Economic Combination by Using AHP

This study is an approach to investigate the viable impacts of screw manufacturing. At the same time, choose the suitable material and selected manufacturing process of screw by considering environmental aspects without sacrificing the economic aspect. It is important to the organisation to improve the environmental aspect. Therefore in this study, the decision making was focused on economic aspects to produce the synergy results between economic and environmental impact. The parameters involved were types of material and manufacturing process of screw which using the available data of environmental and production volume. The two different manufacturing approaches being evaluated were machining and forging process. The types of material concerned for forging process encompassed low carbon steel, alloy steel stainless steel, and aluminium alloy. On the other hand, for machining process, the material being considered in screw manufacturing were cast iron, low carbon steel, alloy steel, stainless steel and aluminium alloy. The information of environmental impacts that generated from SolidWorks Sustainability tool and screw production cost were calculate using Manufacturing cost model, both information was used in Analytic Hierarchy Process (AHP) analysis to obtain local priority of economic and environmental impacts. Then, the ranking of both global and local priorities from economic impact and environmental impacts had enabled the determination of appropriate material used for those selected screw manufacturing process. As result, low carbon steel was chosen for forging process whereas cast iron was excelled in machining process, at the same time, stainless steel was not suggested to be used in both two processes.

An exploration to develop concrete walls using MnxZn1-xFe2O4 ferrite as absorbing material to provide defense against electromagnetic pollution

Concern regarding the shielding effectiveness (SE) of building materials is gaining more response nowadays due to the awareness on the electromagnetic pollution (EMP) that is believed to results in disastrous consequence. A pure concrete inherently providing certain level of SE but it is not enough. Hence additional shielding and absorbing additives are added into the concrete. In this work MnxZn1-xFe2O4 will be added into the pure concrete to enhance its SE performance. The effect of microstructure, compositions, grain sizes, homogeneity, mixture volume of the MnxZn1-xFe2O4 will be considered for the optimization in this mixture. The key component to determine the SE of concrete is their electrical characteristic (relative permittivity and relative permeability). The parallel plate which is proposed previously will be used to determine the electrical characteristic of material and it will also be used for SE measurement.

Dissolution Behaviour of Hazardous Materials from Steel Slag with Wet Grinding Method

Steel slag is a by-product from steel industry and it contains variety of hazardous materials. In this study, the dissolution behaviour and removal potential of hazardous materials from steel slag with the wet grinding method was investigated. The slag was wet ground in the CO2 atmosphere and the slurry produced was filtered using centrifugal separator to separate the liquid and solid sediments. Then, the concentrations of dissolved metal elements in the liquid sediment were analyzed by ICP-MS. The changes of pH during the grinding were also investigated. It was found that the pHs were decreased immediately after the CO2 gas introduced into the vessel. The pHs were ranging from 6.8 to 7.6 at the end of grinding. The dissolved concentration of Zn and Cr were ranging from 5~45 [mg/dm3] and 0.2~2.5 [mg/dm3] respectively. The ratios of Zn removal for stainless steel oxidizing and reducing slag were very high, but those from normal steel oxidizing and reducing slag were very low. It is assumed that the Zn dissolved as ZnOH+ from Zn(OH)2 that formed due to the reaction between ZnO and water. Dissolution of Cr also occurred but in very low quantity compared to the dissolution of Zn. The dissolution of Cr occurred due to the grinding process and small amount of Cr(OH)3 was formed during the grinding. This small formation of Cr(OH)3 resulted to the low dissolved concentration of Cr in the form of Cr(OH)2+. According to the XRD analysis, the Cr mostly existed in the slags as Cr(IIl) in the form of MgCr2O4 and FeCr2O4.

Maximum Torque of Combinations Threat for Spur Gear Based on AGMA Standard

This study is an approach to investigate the transformations curve of gearing safety. Two types of failure can occur on a gear namely the bending stress and the surface pitting failure. There are many standards for gearing in used worldwide such as AGMA, JGMA, ISO, DIN, etc. but the focus of this study will be on AGMA standard. The main data for this study is the torque value applied which can be distinguished into causing bending strength or surface pitting failure. The Autodesk Inventor spur gear component accelerator was used as a tool for data acquisition based on the AGMA standard of calculations. Two gear materials with high value of allowable contact stress compared to its allowable bending stress was chosen for the study as they are predicted to have a transformation curve from surface durability to bending strength when its torque values are plotted against number of teeth. This is then repeated on various gear modules for both materials to obtain a series of combination curves useful in determining the maximum torque that can be applied on the spur gear before failures occur either by bending stress or surface pitting depending on the curve.

Development of Course Management and Monitoring System as a Quality Tools in Engineering Education

Engineering education in Malaysia has moving fast in creating high quality environment for all higher educational institution graduates through several innovative and creative teaching and learning tools and methods. Stress on the quality of delivery method in higher education was also increased in order to assure that the graduates are really fulfilling the needs of the stakeholders. In this work, we have developed a Course Monitoring and Management System (CMMS) to ease the lecturers in managing and monitoring the class. User survey was conducted to identify the actual requirements and data from the survey was used to construct the CMMS. By reducing the lecturers loads in the managing and monitoring activities, lecturers can be more focus in delivering innovative and effective teaching techniques that really notable for the production of high quality graduates.

Characterization of Nickel-Zinc Ferrite Powder Prepared via Sol-Gel Technique in Between 100 MHz to 2 GHz

Electromagnetic Interference (EMI) issue is gaining more attention as the result of proliferation of electrical and electronic devices. In order to reduce the exposure to EMI, shielding and absorbing materials are often applied. This paper discussed the process of forming the nickel-zinc ferrite as one of the absorbing material by mixing the nickel nitrate, zinc nitrate and iron (III) nitrate together. X-ray diffraction, scanning electron microscopy, and dielectric measurement are carried out to reveal the characteristic of the specimen. The sintering temperature determines the formation of a pure spinal nickel-zinc ferrite and grain size.