Volume 26 (2014)
Table of Contents
Table of Contents
Hubungan di antara Pelaksanaan 5S dan Prestasi Hijau Syarikat Pembuatan PKS di Malaysia: Satu Model
Because of the global sustainability agenda, environmental factors are increasingly becoming a priority in the implementation of management practices and competitiveness strategies. Management system such as ISO 9001 and ISO 14001 has the ability to improve company performance toward achieving market competitiveness. However, many companies especially small and medium enterprises (SMEs) are unable to perform these practices. Despite the importance of manufacturing SMEs as a major contributor for the world economic development and environmental pollution, they face resource constraints on resolving environmental issues. As an alternative to existing approaches, the concept of green management with emphasis on green performance improvement, namely in operation and environmental aspects has been introduced. In this context, 5S practice is an approach that is widely used to improve ﬁrm performance without requiring a large investment. The 5S implementation has now evolved from the concept of operational to green performance. However, the successful implementation of 5S depends on the characteristics and internal factors of a company. This study primarily a IMS to examine to what extent the 5S concept has been treated as green management practices in the Malaysian manufacturing SMEs. In this study, several hypotheses and a conceptual model of the relationship between 5S implementation and green performance has been built. In the proposed model, several factors that include strategic planning, commitment and implementation procedures have been identiﬁed to inﬂuence the successful implementation of 5S to achieve green performance.
|2.||A Novel Prototype and Simulation Model for Real Time Solid Waste Bin Monitoring System
Md. Abdulla Al Mamun, M.A. Hannan & Aini HussainAbstract
This research deals with an exclusive solution to monitor the solid waste bin condition on real time. The system architecture is designed using wireless sensor networks. A set of carefully chosen sensors are used to measure the status of the bins and ZigBee and GPRS are used as communication technologies. The physical architecture of the system contains three levels such as smart bins for the measurement and transmission of bin status, gateways for storing and forwarding bin data to server and control station for storing and analyzing the data. After the framework design, a simulation is performed using Castalia to ensure the feasibility and accuracy of the system. The simulation is performed for ten bins and taking ten samples from each bin where a ﬁll level threshold of 15 is considered. The simulation result shows that, the proposed system would be able to automate the solid waste monitoring process that helps to optimize waste collection route.
|3.||Sun Outage Calculator for Geostationary Orbit Satellites
Jouko Vankka & Antti KestiläAbstract
Sun outages in satellite communication occur when the sun, a powerful broadband microwave noise source, passes directly behind the satellite (when viewed from Earth), causing the receiver with the beam directed towards the satellite to pick up the satellite signal and the noise from the sun. A new type of calculator was developed to accurately determine the occurrence of such phenomena for any chosen geostationary satellite and receiver location combination. The calculator outputs the degradation experienced by the satellite signal, enabling the receiver to take suitable countermeasures. The results from the calculator program were compared with measurement results and agreed to a good degree. Several different open-source calculation tools exist for sun outages. However, these tools are either built from incorrect assumptions or lack of a useful function, leading to inaccurate predictions for strength and beginning/ending time of the outages. The program described in this work has more inputs, such as the solar flux, with which the sun’s activity can be considered when calculating outage duration and receiver noise temperature. Regression analysis was used to develop a linear model to estimate daily solar flux at a frequency of interest from the day’s solar flux 2800 MHz observations (F10.7).
|4.||Microstructural Properties of Semisolid Welded Joints for AISI D2 Tool Steel
M.N. Mohammed, M. Z. Omar, J. Syarif, Z. Sajuri, M. S. Salleh & K. S. AlhawariAbstract
The aim of this study is to investigate experimentally the microstructural evolution of the joints using ledeburitic AISI D2Tool Steel parts. The application of a new process of the semisolid joining of two parts of AISI D2 cold-work tool steel is proposed using a partial remelting method. Samples were heated in an argon atmosphere up to 1300°C and held for10 minutes. Metallographic analyses along the joint interface showed a smooth transition from one to the other and neither oxides nor micro cracking was observed. The current work successfully confirmed that avoidance of a dendritic microstructure in the semisolid joined zone and high bonding quality components can be achieved without the need for force or complex equipment when compared to conventional welding processes.
|5.||Effect of Aluminium Content on the Tensile Properties of Mg-Al-Zn Alloys
N. Abdul Latif, Z. Sajuri & J. SyarifAbstract
The aim of this study is to investigate the effect of aluminium content on microstructure, tensile properties and work hardenability of Mg-Al-Zn alloys. Two types of magnesium alloys were investigated i.e. AZ31 and AZ61, where the aluminium contents were 3% and 6%, respectively. Microstructure observation revealed that higher aluminium content decreases the grain size and increases the volume of Mg17Al12 precipitations. From the tensile test, AZ61 demonstrated higher yield stress and tensile strength while maintaining the elongation as compared to AZ31. The work hardening rate for AZ61 was also greater as compared to that of AZ31.
|6.||Tensile Properties and Strain Response of Cu-Al Bi-Metal Tube
A.H. Baghdadi, I. S. Misran, Z. Sajuri & J. SyarifAbstract
Recent high price of copper in global market forced the heat, ventilation, and air condition (HVAC) industry players to find alternative materials with relatively lower market price compared to copper such as aluminium for replacement. This study characterizes tensile properties and strain response of new Cu-Al bi-metal tubes i.e. aluminium cladded copper (ACC) and copper cladded aluminium (CCA) in order to look at the possibility of applying the bi-metal tubes in HVAC industries. The result shows that tensile properties of CCA tubes was higher than that of ACC bi-metal tubes in two different strain rates of 1 × 10-3 and 1 × 10-1 sec-1. Also, Strain response refers to the sample elongation at break shows a higher elongation value of CCA samples compared to ACC.
Kajian Pelemahan Hujan pada Jalur Ku dan Jalur Ka di Malaysia Menggunakan Data Satelit TRMM
Attenuation due to rain can severely degrade the radio wave propagation at frequencies above 10 GHz. The impact is more severe in tropical and equatorial region like Malaysia which encounters higher rainfall intensity throughout the year. Total rainfall accumulation, obtained from Tropical Rainfall Measuring Mission (TRMM) satellite have been used to derive 1-minute rainfall rates for a period two years (2011-2012) used to calculate the prediction of rain attenuation at Ku and Ka-band all over Penisular Malaysia and at random locations in Sabah and Sarawak. Measat 3 is applied for practical measurement to calculate rain attenuation prediction. The study of effect monsoons and La-Nina with El-Nino fenomenon on rain attenuation were conducted. In order to study the fenomenon of El-Nino and La-Nina, the period of this study are extend to five years, from 2008 to 2012. ITU-R model has been selected to calculate the rain attenuation because it is the best model based on the result of previous researchers. The results from this study shows that Sabah and Sarawak have lower rain attenuation compared to Peninsular Malaysia even though Peninsular Malaysia produces having heavy rainfall throughout the year. This studies is very useful to guide the design and applications of low availability of satellite-to-Earth communication systems specifically in Malaysia.
|8.||Pembangunan Kawalan Logik Kabur dalam Reaktor Lapisan Terpadat (Development of Fuzzy Logic
Controller for Packed Bed Reactor)
Ahmad Zuhairi Abdul Ghafar, Norliza Abd Rahman & Faezah EsaAbstract
Fuzzy logic control system on simulation model was created using MATLAB Simulink R2011a in order to control the isomerization process of glucose to fructose in recycled and non-recycled packed bed reactor. Immobilized glucose isomerase catalysts the process along with regulation of pH and temperature. Mathematical equations on rate of fructose production,temperature changes and pH changes were created and modulated into a simulation model. Fuzzy logic controller was applied onto this simulation model to control the pH and temperature. The calculated error from fuzzy logic control system was compared with PID control and ON/ OFF control at constant pH (pH 8) and temperature (60°C) respectively. Fuzzy logic control system was found to exhibit lower error compared to ON/OFF control system in both non-recycled and recycled packed bed reactor. The same finding was obtained on camparison to PID control system. Conserving pH and temperature at optimum conditions are important for an efficient process. Thus, lower calculated error of fuzzy logic control indicated its potential in regulating isomerization process of glucose to fructose in packed bed reactor.
|9.||Heat Transfer Enhancement of Laminar Flow in a Circular Tube Using Swirl/Vortex Generator
Sami D. Salman, Abdul Amir H. Kadhum, Mohd S. Takriff & Abu Bakar MohamadAbstract
Swirl/vortex flow generator is an important form of passive augmentation techniques consist of a variety of tube inserts, geometrically varied flow arrangements and duct geometry modifications that produce flows. Twisted-tape is one of the most important members of this form which used extensively in different type heat exchangers. This paper presents a research on heat transfer enhancement and friction factor characteristics in a circular tube using CFD simulation. Plain twisted tape inserts with twist ratios (y = 2.93, 3.91) and slant baffled twisted tape inserts with baffle angle 30° and twist ratio (y= 2.93) have been used for the simulation. The results obtained by simulation matched with the literature correlations for plain tube with the discrepancy of less than ±8% for Nusselt number and ±6.25% for friction factor. The results have also revealed that the heat transfer in term of the Nusselt number enhanced with increases of Reynolds number, decreases of twist ratio. Among the various twist ratios, the slant baffled twisted tape with twist ratio of y = 2.93 has offered a maximum heat transfer enhancement with significant friction factor.
|10.||Development of Bicycle Shift Models in Universiti Kebangsaan Malaysia Campus
Amiruddin Ismail & Shazrizil ZakariaAbstract
Cycling is suitable for short trips and take shorter commute time for students who are living in the campus. Moreover, it requires lower costs and can reduce environmental pollution. However, cycling in campus is not well received by the students.This is due to certain factors such as hilly terrain, uncertain weather, and also the exposure to road traffic accidents. A survey had been conducted in UKM Bangi campus to identify the factors that can influence students to choose cycling as the main choice of transport. Surveys were targeted to 170 respondents from the students in the campus. Two bicycle shift models were developed based on travel distance of non-hilly terrain and travel distance if covered lane provided. 76.5%of the respondent agreed that hilly terrain makes bicycle is not an option inside campus while 79.4% believe that the weather condition makes them not to choose bicycle. From both model, it is seen that the probability to shift to bicycle is increased as the travel distance increases if the terrain is not hilly and if there is covered lane provided. Overall, the study is a success and might be useful for future research on sustainable transportation system in campus.
|11.||Evaluation of Physical Properties of Clays Mixed with Silica Sand
A. Akbar Firoozi, M.R. Taha, A. Asghar Firoozi & Tanveer A. KhanAbstract
This study examined the effects of heat treatment on two types of clays mixed with silica sand under laboratory conditions. Soils were subjected to three varied temperatures, i.e. 100, 250 and 500°C. The soil properties studied were Atterberg’s limits, optimum water content and unconfined compressive strength. Experimental results showed that the temperature greater than 100°C resulted in a reduction in Atterberg’s limits, optimum water content and unconfined compressive strength.For illite and silica mixture heating the soils at 500°C, liquid limit, plastic limit, optimum water content and unconfined compressive strength were reduced to 12%, 0%, 40% and 0%, and for kaolinite and silica mixture the above characteristics reduced to 18%, 0%, 50% and 0% respectively when matched to soil specimen’s properties at ambient temperature. Where as maximum dry density for illite and kaolinite increased by 5% and 8% respectively for the two clays.
Analisis Penyerakan Isyarat Gelombang Mikro Elemen Gelung Segi Tiga dari Pelbagai Jenis Filem
A study on the performance of scattering Ku-band microwave signals from an element designed with triangular loop shape made of different types of conductive thin film is presented in this paper. In this study, four types of transparent film have been used i.e. Kapton, ITO, AgHT-4 and AgHT-8. Each of this film was then positioned on top of glass of solar panel which is based with RT/Duroid 5880 substrate. The element was designed to be operated at Ku-band frequency range. Simulation results obtained from the CST microwave studio software showed that element of Kapton film exhibits the best performance.The linear phase range reaches 361°, while the phase slope goes down as low as 0.063°/μm. It is also demonstrated that the dual frequency operational element contributes the highest bandwidth of around 15.2% and also the best candidate to form a solar reflect array antenna for terrestrial applications.
|13.||An Enhanced Opposition-based Firefl y Algorithm for Solving Complex Optimization Problems
Ling Ai Wong, Hussain Shareef, Azah Mohamed & Ahmad Asrul IbrahimAbstract
Firefly algorithm is one of the heuristic optimization algorithms which mainly based on the light intensity and the attractiveness of firefly. However, firefly algorithm has the problem of being trapped in local optimum and slow convergencerates due to its random searching process. This study introduces some methods to enhance the performance of original firefly algorithm. The proposed enhanced opposition firefly algorithm (EOFA) utilizes opposition-based learning in population initialization and generation jumping while the idea of inertia weight is incorporated in the updating of firefly’s position. Fifteen benchmark test functions have been employed to evaluate the performance of EOFA. Besides, comparison has been made with another existing optimization algorithm namely gravitational search algorithm (GSA). Results show that EOFA has the best performance comparatively in terms of convergence rate and the ability of escaping from local optimum point.