Volume 29(1) 2017

Table of Contents

No. Article Page  
1. Kesan Lilin Ke Atas Sifat Hidrofobik Permukaan Daun Pisang

(Wax Effect on Hydrophobic Properties of Banana Leaves)

Hasrawati Abu Hassan*, Mariyam Jameelah Ghazali, Nurfatihah Mohamed Zainuddin & Che Husna Azhari

Wax extraction of two types of banana leaves: Musa parasidiaca L. and Musa acuminata Colla; were conducted by immersing the banana leaves in chloroform in order to investigate the hydrophobicity and self-cleaning behaviour. Then, the resulting solvent was evaporated and crystallized at room temperature. Morphology of the both waxes was observed by using Field Emission Scanning Electron Microscope (FESEM) and the chemical elements obtained which were carbon and silicon by using Energy Dispersive X-ray Analysis (EDX). The melting point of Musa parasidiaca L. and Musa acuminata Colla were 80.2ᵒC and 82.9 respectively whereas the water contact angle of the wax surfaces of Musa parasidiaca L. and Musa acuminata Colla 137.3ᵒ and 132.8ᵒ. Both waxes exhibited hydrophobicity due to the contact angles values that exceeded 90ᵒ and Musa parasidiaca L. showed higher contact angle and suitable for biomimetic application. The characterization of the banana leaves wax can be a source of coating and textiles industry.

Keywords: wax; Musa acuminata Colla; Musa Parasidiaca L.; contact angle; hydrophobic

DOI : dx.doi.org/10.17576/jkukm-2017-29(1)-01
1 – 7
2. An Investigation on the Surface Austempering of Ductile Cast Iron

Abdolali Fayyaz*, Nasser Varahram, Parviz Davami

This research presents surface austempering of ductile cast iron. Surface of pearlitic ductile cast iron samples were austenitised and heated to 810 and 850 °C and held at these temperatures for 90 and 105 sec and then austempered at a temperature of 325 °C for 60 and 90 min. The microstructure of samples was evaluated by optical microscopy. The hardness profile in polished cross section was also determined. In addition, the depth of austempered layer was measured. The result indicated that temperature and time of austenitisation intensely effect on surface austempering process. The test results also revealed that the hardness of austempered layer increase when the austenitising temperature and time increase. After surface austempering of ductile cast iron samples, the highest hardness achieved 450 HV in austempered surface-layer. The highest depth of austempered layer 1.7 mm was obtained.

Keywords: Austempered ductile iron; surface hardening; hardness; microstructure; austenitisation

DOI : dx.doi.org/10.17576/jkukm-2017-29(1)-02
9 – 12
3. Kebolehpercayaan & Kesahan Soal Selidik Kelewatan dalam Projek Pembinaan Menggunakan Model Pengukuran Rasch

(Reliability & Validity of the Construction Delay Questionaire using the Rasch Mesurement Model)

Muhamad Azry Khoiry*, Noraini Hamzah, Wan Hamidon Wan Badaruzzaman, Norngainy Mohd Tawil

Construction industry is one of the industry that generates economy and at the same time provides job vacancy and national treasure. However, delay in construction project is a global phenomenon which occurred at almost every country, thus retards the development of the country. There are numerous of studies on construction delay using questionnaire done by researchers worldwide. Reliability and validity of the questionnaire should be reviewed in advance to ensure the effectiveness of the survey conducted. It is to obtain the appropriate data and the data can be used for futher analysing. The objective of this research is to get the reliability and validity of the questionnaire on construction delays projects using the Rasch measurement model. For purposes of data analysis, this research uses Winstep a software-based Rasch Modal measurement. Beside Cronbach alpha reliability, Rasch Measurement Model can provide the reliability of the item and respondent. Validity of data evaluated from various aspects, including the items and the respondent misfit, principal component analysis and rating scale. A total of 54 of the 64 items were identified contributed to delays in construction projects in Malaysia.

Keywords: validity; reliability, construction delay; rasch analysis; rating scale

DOI : dx.doi.org/10.17576/jkukm-2017-29(1)-03
13 – 21
4. Calibrating and Modelling of Statistical Delay for Signalized Intersections at Al-Nasiriyah City in Iraq

Abdullah Hayal Khalaf Alshnawa*, Amiruddin Ismail, Alla Jaber Essa, Ameer Abdul Adheem Hussein

In this paper develops an empirical delay model for delay prediction by taking lane group parameters to make delay model in the field where delay have considered very important measure that effects at signalized intersection because of relation of delay with performance of signalized intersection, lost travel time, fuel consumption, feasible of movement, discomfortable of drivers also, it is considered the primary measure to determine the level of service at signalized intersection. The main aim of this study is to make a field delay model at signalized intersection by using microsimulation software to calibrate data and using statistical software (SPSS) to create model. The methodology of the study is made by using video recording and manual collected data by taken three biggest signalized intersections where the collection data was very challenged specifically speed forward and uncontrollable drivers and others factors. Sidra Intersection 6.0 is described as an advanced micro-analytical model with a lane-by-lane method and a vehicle drive-cycle model that is used to estimate capacity and performance measures through an iterative method. Calibration of the software is very necessary to find accurate model that can be described the field delay. Multiple Linear Regression analysis (MuLRa) has been generally statistical method to create a model. It has been taken into consideration in the modelling of delay at signalized intersection and adjusted R² is 80% with multi factors that effect on field delay. Vehicle speed has been improved very significance level and impact factor on delay at signalized intersection by lane group experimental method and this finding very important for all simulation software should be taken that in the accounts.

Keywords: Statistical delay model; signalized intersection; calibration; multiple linear regression analysis; lane group; Speed vehicles

DOI : dx.doi.org/10.17576/jkukm-2017-29(1)-04
23 – 34
5. Optimization of Stir Casting Method of Aluminum Matrix Composite (AMC) for the Hardness Properties by Using Taguchi Method

Amir Arifin*, Gunawan, Irsyadi Yani, Muhammad Yanis, Raka PradiftaAbstract

Aluminum matrix composite (AMC) was fabricated using stir casting with fly ash and SiC as reinforcing materials. In this work, Taguchi optimization technique was utilized to analyze the significant contributions of stir casting parameters on the hardness properties of AMC. For this reason, stir casting was carried out by utilizing the combination of process parameters based on three-level of L9 Taguchi. The signal-to-noise (S/N) and the analysis of variance (ANOVA) were used to find the optimum levels and to indicate the impact of the process parameters on the hardness properties. The results show that some of process parameters have significant effect on the hardness, by comparing with the other three sintering factors, the composition of reinforcement materials gave the most significant effect on the hardness

Keywords: Taguchi method, Stir casting, Fly ash, Aluminum matrix composite

DOI : dx.doi.org/10.17576/jkukm-2017-29(1)-05
35 – 39
6. Litar Penuai Tenaga Hibrid Mikro untuk Aplikasi Bioperubatan

(Micro Hybrid Energy Harvester Circuit for Biomedical Application)

Jahariah Sampe*, Nor Afidatul Asni Semsudin, Farah Fatin Zulkifli, Burhanuddin Yeop Majlis

The deployment of energy harvester as a power supply attracts high attention especially for micro-scale devices. It is utilizing the ambient energy sources to produce electric energy. In-depth research has been carried out to achieve energy harvester with high efficiency and sensitivity. Three energy sources are used as input which are thermal energy, vibration and Radio Frequency (RF). The thermal energy input is in the form of DC voltage while RF and vibration is in the form of AC voltage. All these inputs are set to 0.02V, 0.5V and-20dBm respectively. The operation frequency that has been used for vibration input is 10Hz while for RF input is 915MHz. The full-wave rectifier circuit is used to convert AC to DC vibration signal. Meanwhile, the voltage multiplier circuit is constructed by implementing substrate modulation techniques to multiply the input voltage. All these individual circuits are combined using the voltage adder circuit to form a complete hybrid energy harvester system. The energy harvester circuit is built and simulated using PSPICE software with the resistor load of 1MΩ. The complete energy harvester circuit with hybrid input has successfully achieved output voltage approximately 2.12V and suitable for use as an alternative power supply to biomedical device applications. The device is Health Monitoring device that requires minimum supply source of 1.7V.

Keywords: Hybrid energy harvester; efficiency; sensitivity; micro-scale device

DOI : dx.doi.org/10.17576/jkukm-2017-29(1)-06
41 – 48
7. Two Component Injection Moulding of Bi-material of Stainless Steel and Yttria Stabilized Zirconia – Green Part

Ukwueze Bonaventure Emeka*, Abu Bakar Sulong, Norhamidi Muhamad, Zainuddin Sajuri & Farrahshaida Salleh

The two component injection molding (2C-PIM) is a promising technique for production of small, complex and high density, metal-ceramic parts in large scales. This method is a viable option for integrating incompatible functions or properties of the materials in a singular part or component. Thus, the production of near net shaped components via 2C-PIM is imperative due to cost effectiveness resulting from high unit volumes. In this study, the feasibility of joining stainless steel (17-4PH) and 3mol% yttria stabilized zirconia (3YSZ) materials in their green states was investigated. Two feedstock of SS17-4PH and 3YSZ powder materials was prepared based on optimum solid loading of 3vol% lower than value of the critical loading. The critical solid loading for the SS17-4PH and 3YSZ powder materials were 71vol% and 53vol% respectively, based on the oil absorption technique ASTM: D-281-12. The binder system utilized comprises of 60wt.% palm stearin (PS) and 40wt.% low density polyethylene(LDPE). The two materials were injected sequentially using the screw type injection molding machine (BOY 22A) to form a bi-material component. The green properties were investigated. The morphology of the individual green parts and composites depicted that the powders were optimally dispersed in the binder matrix indicating good mixture and compaction of the green components. The flexural strength of the single components of the bi-material was above 5MPa. The strength of the bonding zone which was 1.4MPa indicates an evidence of bonding.

Keywords: two component injection molding; Material characterization; Morphology; Density

DOI : dx.doi.org/10.17576/jkukm-2017-29(1)-07
49 – 55
8. Car Driver Attitude towards Road Safety Measures

Hussin A.M Yahia*, Sina Safinia, Noof Khamis Al Musharfi & Saband S.I.A. Ali

Road traffic accidents (RTA) constituted a severe public problem in all countries of the world. Roughly about 1.5 million people around the world die in traffic-related accidents. Its absolute impact is exacerbated by the fact that RTA have become the leading cause of death, especially among young adults who constitute the most economically productive age groups of the larger society. Road traffic accidents also prove to be an issue of economic and social. More than 70 % of the injuries and victims of accidents were in low and middle-income countries. The integral role of knowledge and practice of road safety measures necessitate further emphasis in the RTA prevention. The present study seeks to evaluate the road safety measures’ knowledge among car drivers in Tripoli – Libya. A total of 389 drivers had taken in this study. A questionnaire was used to gather some relevant information from the participants. The data collected was run in analysis using SPSS version 19. From the 389 drivers, 310 (79.7%) were male and 79 (20.3%) female. The study results have shown that gender differences in attitudes towards traffic law indicate that there is no significant difference between both sexes. Female had a marginally higher awareness than males with regard to certain substantial issues such as eating, drinking or smoking while driving and using cassette / radio or using the telephone while driving were particularly significant ( P-value = 0.04). Explanations and results of the behaviors of the drivers about safety measures on the roads are discussed.

Keywords: Road accidents; knowledge; awareness; attitudes; traffic law.

DOI : dx.doi.org/10.17576/jkukm-2017-29(1)-08
57 – 61