Megat Mohamad Hamdan Megat Ahmad

Mechanical and Electrical Properties of Coconut Coir Fiber-Reinforced Polypropylene Composites

Abstract: Natural Fibers have an outstanding potential as reinforcement in thermoplastics. The objectives of this experiment are to evaluate the suitability of producing Fiber composites using coconut coir fibers. This study deals with the preparation of coconut coir composites by using compression technique in which good interfacial adhesion is generated by a combination of fiber modification and matrix methods. Initially the coconut fibers were treated in order to improve resin fiber interfacial bonding. The treatment agents used included alkali, stearic acid, acetone, and potassium permanganate. The various reactions between the modified fiber and polypropylene chains were used improve the interfacial adhesion between the fiber and polymer using the new bond. Generally, composites that contain treated fiber have a higher tensile modulus and greater flexural modulus than do untreated fiber composites. Typical mechanical tests on strength, flexability, hardness, and dielectric were performed and the results are reported.

The Effect of Environmental Treatments on Fiber Surface Properties and Tensile Strength of Sugar Palm Fiber-Reinforced Epoxy Composites

Fiber glass has been used widely in manufacturing industries, especially marine industries, because of low cost and high strength. However, glass fiber can cause acute irritation to the skin, eyes, and upper respiratory tract. This study looked at the possibility of substituting glass fiber with natural fiber in composite materials. The surface properties of sugar palm fiber (Arenga pinnata) were modified using seawater and freshwater as treatment substances. This led to biological, chemical, and water degradation of the sugar palm fiber. Morphological and structural changes in the fibers were investigated using a scanning electron microscope (SEM). A series of tensile tests based on ASTM D638-99 was carried out on epoxy composites with 15% sugar palm fiber by volume. It was found that seawater and freshwater treatments improved the surface properties of the sugar palm fiber and thus resulted in better adhesion quality as compared to untreated fiber. An improvement in tensile strength also supported this finding. Treatment with seawater for 30 days proved to be the best, with 67.26% increase in tensile strength.

Modeling the technology transfer process in the petroleum industry: Evidence from Libya

The purpose of this study was to propose a conceptual model for technology transfer (TT) that houses several factors. These factors are believed to influence the processes’ effectiveness and guide the TT performance. In addition, this study aimed to explore TT performance and the relationship between TT government support, infrastructure, TT environment, and TT learning capability. Oil production in Libya is dependent on foreign technology transferred into the country by foreign multinational petroleum companies. During the 1980s, the Libyan government launched a program of development known as “Libyanization” in the Libyan petroleum industry in an effort to create an absorptive capacity to acquire petroleum technology dominated by foreign companies. This study evaluates the level of technical change because of TT programs and the impact on knowledge and competitiveness performance of the Libyan petroleum industry. A questionnaire survey was administered to companies in the Libyan petroleum industry. There were 201 responses from industry professionals in the Libyan petroleum industry that were analyzed using structural equation modeling (SEM), exploratory factor analysis (EFA), and confirmatory factor analysis (CFA). In addition, the significance of direct and indirect interrelationships between model factors was determined through SEM. A path model was estimated and specified to include three process enablers, namely government support, host characteristics, and learning technology capability, and one outcome factor named TT performance. The results suggested that government support factor (government support, laws and regulations, petroleum industry strategy, international quality standards, and information technology) and technology learning capability factor (i.e., supervision, adoption, teamwork, absorption, training, technology complexity, and industry knowledge) were determined to be the key predictors of TT performance to the host petroleum industry.

Particular model for improving failure mode and effect analysis (FMEA) by using of overall equipment efficiency (OEE)

Almost all of factories use failure mode and effect analysis (FMEA) technique to reduced risk priority number (RPN). This paper proposes a new model to reduce RPN by improving overall equipment efficiency (OEE) by using of heuristic mathematic model based on total productive maintenance index. Three factors are considered: (i) probability of failure (Occurrence), (ii) severity and (iii) distinction. A textile industry is used as a test case that produces some product for seat cover. It was shown that the RPN decreased in FMEA.

Pre-treatment by water retting to improve the interfacial bonding strength of sugar palm fibre reinforced epoxy composite

Polymer composites using natural fibres as the reinforcing agents have found their use in many applications. However, they do suffer from a few limitations, due to the hydrophilicity of the natural fibres which results in low compatibility with the hydrophobic polymer matrices. This paper presents the alternative low-cost methods of sugar palm (Arenga pinnata) fibre surface treatments to improve the fibre-matrix interfacial adhesion. Fibre surface modifications were carried out by water retting process where the fibres were immersed in sea water, pond water and sewage water for the period of 30 days. The results showed that the tensile and flexural strengths of the treated fibre reinforced composites increased as the fibre treatment duration increased. This indicates that the treatments had significantly improved the fibre-matrix bonding strength.

Solution of Navier‐Stokes equations by fourth‐order compact schemes and AUSM flux splitting

Purpose – To develop a high‐order compact finite‐difference method for solving flow problems containing shock waves.Design/methodology/approach – A numerical algorithm based on high‐order compact finite‐difference schemes is developed for solving Navier‐Stokes equations in two‐dimensional space. The convective flux terms are discretized by using advection upstream splitting method (AUSM). The developed method is then used to compute some example laminar flow problems. The problems considered have a range of Mach number that corresponds to subsonic incompressible flow to hypersonic compressible flows that contain shock waves and shock/boundary‐layer interaction.Findings – The paper shows that the AUSM flux splitting and high‐order compact finite‐difference methods can be used accurately and robustly in resolving shear layers and capturing shock waves. The highly diffusive nature of conventional flux splitting especially on coarse grids makes them inaccurate for boundary layers even with high‐order discreti...

Elastohydrodynamic lubrication study of hard rolling contact using boundary element method

Presents a study on the application of boundary element method (BEM) to the solution of elastohydrodynamic lubricated hard rolling contacts in comparison with a solution using finite difference method (FDM). The developed program for the solution of Reynolds equation and the elasticity equation give results of pressure distribution and the lubricant film thickness for steady state, isothermal Newtonian lubricant behavior. Compares the BEM results and the computer effort with the solution using FDM. Uses an iterative Newton‐Raphson method to solve the non‐linearity of the problem. Discusses the effects of Hertzian pressure and rolling speeds on film thickness and pressure distribution. The numerical scheme of BEM has proved to have the advantage of being very effective and optimum in terms of accuracy, less computational effort and good constancy compared to other applied numerical techniques.

Optimal Design for a Thermosyphon Solar Water Heater Convenient for Malaysia

A thermosyphon solar water heating system with in‐tank auxiliary electric heater has been simulated according Malaysian hot water consumption profile using TRNSYS simulation program. The optimum value of a parameter is defined as the value which maximized the annual solar fraction of the system. This paper has a good deal of information concerning sizing of common components of thermosyphon solar water heater operated under certain condition (load volume, distribution profile and temperature). The results indicate that collector should be tilted at O + (→ 7° 37°) for all collector areas. Vertical storage tank has better performance in tropical climate (The average annual solar fraction for vertical was 88% and for horizontal was 82.9%).