ADDRESS

Faculty of Engineering and Built Environment
Universiti Kebangsaan Malaysia

Volume 31(2) 2019

Table of contents

Front Page

No. Article Page  
1. An Assessment of Indigenous Innovations in Wet Fufu Paste Production: Prospects, Constraints and Processing Risk Implications

Lawal Nurudeen Samuela*, Ogedengbe Kolawoleb, Ojo Olukayode Omotayo Smithc & Nudamajo Paul Segbenua
Abstract

Immense opportunities in cassava-tuber value addition have resulted in the development and application of indigenous innovations by small and medium scale cassava processors across the country. This study examines the prospects and challenges faced by indigenous wet fufu paste processors; highlighting waste generation and handling, processing techniques and inherent processing risks. Data were collected using a structured questionnaire administered in 50 processing clusters scattered across the study area (Ifo, Ogun State, Nigeria). Target oral interviews were used to validate the questionnaire and elicit information on the processing clusters, adopted processing techniques, processing equipment, wastewater generation and disposal techniques, and processing risk factors. Wastewater quality parameters were also obtained to assess the level of compliance with permissible limits and the risk implications of disposed of effluent. Processing operations were entirely manual and dominated by young indigenous women working in organized groups of 2-6 people depending on the expected output. About 47% of the tested wastewater parameters were above local (NESREA – National Environmental Standards and Regulations Enforcement Agency) and international (WHO – World Health Organization) limits. Inorganic constituents like sodium, calcium, magnesium, phosphate and heavy metals were found in low quantities. However, heavy metals (cadmium, lead and chromium) exceed the permissible limits. Open land disposal (50%), nearby streams/rivers (13%) and open drains (37%) are the predominant wastewater disposal technique adopted by processors. The risk implications of these techniques were highlighted, and alternative solutions were proffered to mitigate the identified risks and encourage the development of improved innovations among processors.

Keywords: Cassava-tuber; Fufu processors; Wastewater disposal; Risk; Indigenous innovations

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-01
185-192
2. The Application of Multi-Phase Power Distribution Line with Pure Energy Conversion

Erol Can*
Abstract

This paper discusses the power transmission of a six-phase power line with a six-phase LPWM inverter. The 20 km long line with six-phase is formed to be fed from the 6-phase multi-level inverter. The structure of the line and the elements of the power line are given in the design phase. After that, mathematical analysis of the power line is done to present information on the line structure and the relationship between the variables of the line. In the application stage, the described line is operating in Matlab Simulink. The input voltage of the line, the voltage of the RC parallel filter on the line and the voltage of the 1MW load on the line are measured. Six phase flux of the power is measured according to b2 and b4 bus points. Harmonic distortion of created voltages is measured. The harmonic distortion of the voltage on the Z2 impedance is 0.12%. This level of deterioration is well below the international standard of 5% and is an ideal result for loads that need a pure multi-phase magnetic field. 6-phase voltage is measured at 244V amplitude on a 6-phase load with 1 MVA power connecting the secondary side of the transformer. Then, the distortion of this voltage is close to zero. This result is highly desirable for a load on the power line. Based on the results obtained, the power is transmitted over a 20 km long line with high quality successfully.

Keywords: Transmission of a six-phase; six-phase LPWM inverter; a high quality

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-02
193-199
3. Analysis of Fluid Flow Patterns in Cylindrical Vessels of Anaerobic Digester using CFD

Muhammad Shakaib*, Antash Najibb & M. Ehtesham ul Haquec
Abstract

The production of energy from biomass and waste material is gaining popularity worldwide due to the expected depletion of fossil fuels shortly. A device commonly used is anaerobic digester in which microorganisms react with biomass/biodegradable in a vessel and produce useful gases. The performance of anaerobic digester depends on mixing or proper contact of bio-matter with microorganisms. In this paper, flow behaviour is studied in cylindrical vessels of anaerobic digester using Computational Fluid Dynamics (CFD) technique. The study includes simulations for various cylinder dimensions obtained by changing the height and diameter of the digester vessel and locations for fluid inlet and outlet. The results are shown in qualitative terms using velocity profiles and quantitatively in terms of volume of the stagnant zone. The comparison of several geometries at a constant velocity indicates the considerable effect of cylinder aspect ratio (height to diameter ratio) and positions and numbers of inlet and outlet ports on mixing performance. The influence of inlet velocity/Reynolds number is also examined for a few cases. The digester which has an inlet and two outlets on the curved surface (both on the same side) is found to be most suitable. The volume of the dead zone in this configuration at various Reynolds number is less than 30% (based on 0.5% criterion).

Keywords: Anaerobic digestion; CFD; Reynolds number; stagnant zone

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-03
201-208
4. A Study on Tiredness Assessment by Using Eye Blink Detection

Arafat Islam, Naimur Rahaman & Md Atiqur Rahman Ahad
Abstract

In this paper, the loss of attention of automotive drivers is studied by using eye blink detection. Facial landmark detection for detecting eye is explored. Afterward, eye blink is detected using Eye Aspect Ratio. By comparing the time of eye closure to a particular period, the driver’s tiredness is decided. The total number of eye blinks in a minute is counted to detect drowsiness. Calculation of total eye blinks in a minute for the driver is done, then compared it with a known standard value. If any of the above conditions fulfills, the system decides the driver is unconscious. A total of 120 samples were taken by placing the light source front, back, and side. There were 40 samples for each position of the light source. The maximum error rate occurred when the light source was placed back with a 15% error rate. The best scenario was 7.5% error rate where the light source was placed front side. The eye blinking process gave an average error of 11.67% depending on the various position of the light source. Another 120 samples were taken at a different time of the day for calculating total eye blink in a minute. The maximum number of blinks was in the morning with an average blink rate of 5.78 per minute, and the lowest number of blink rate was in midnight with 3.33% blink rate. The system performed satisfactorily and achieved the eye blink pattern with 92.7% accuracy.

Keywords: Facial Landmarks; Eye Closure Time; Eye Blinks; Eye Aspect Ratio (EAR); Blinks per Minute

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-04
209-214
5. Glacier Mapping with Object based Image Analysis Method, Case Study of Mount Everest Region

Dhval Thankia*, Dippal Isrania & Ashwin Makwanaa
Abstract

Substantial progress in Geoinformatics System in recent years leads to the research in monitoring and mapping of glaciers. Monitoring glacier in the mountain region with traditional manual method is very crucial and time-consuming. Glaciers are melting because of global warming. Melting of glaciers can causes calamities like rising in sea level, glacial lake outburst, avalanches etc. Glacier monitoring using multi-temporal data for objects on the surface of the glacier is hard to classify. This paper gives an insight into the importance of Geo-spatial data and object-based image analysis method for satellite image processing. The object-based image analysis benefits more compared to traditional pixel-based image analysis as it is more robust and noise removing more image features etc. Spectral data with multiple bands is the backbone of surveying and monitoring of glacier. In this paper case study of Mount Everest region (27 48° 32N, 86 54° 47E) is represented. The remotely sensed image needs to be taken in a cloud-free environment. Object-based image classification is done in recognition tool. Also, the step by step methodology of object-based classification, segmentation and post-classification possibilities are discussed. Finally, the paper presents several representations of indexes. The integration of indexes is useful for accurately classifying the different part of terrain, lake, vegetation and glacier.

Keywords: Glacier Mapping; Object Based Image Analysis; Classification: Geographic information system; Geo-spatial

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-05
215-220
6. Modeling Severity of Road Traffic Accident in Nigeria using Artificial Neural Network

Ibrahim Khalil Umar* & Huseyin Gokcekus
Abstract

In this study, an Artificial Neural Network (ANN) was used to model injury and fatality index in Nigeria with the aim to determine the effects of the number of GSM subscription (NGS) on the injury and fatality index in the country. Fifty-seven-year data from 1960-2016 comprising of Gross Domestic Product (GDP) per capita, population, NGS, the total number of traffic accidents, number of fatality and injury per year were used for developing the model. The result of the ANN implies that adding the NGS to the model has increased the model performance in both training and testing with a determination coefficient increasing by 18.7% and 2.5% in testing for fatality and injury index respectively. Comparing the performance of the ANN models and regression analysis shows the superiority of the ANN technique over the regression analysis for both injury and fatality index models. The goodness of fit of the model was further checked using t-test at 5% level of significance and the result proved the ANN approach as a powerful tool for modeling the severity of road traffic accident. Strict enforcement against the use of phone while driving will help reduce the accident severity caused as a result of phone usage while on wheels.

Keywords: Road traffic accident; Injury index; Fatality index; GSM subscription; Nigeria

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-06
221-227
7. Effects of Nanopowder Addition on Rheological Properties of Feedstock for Micropowder Injection Moulding Process

Javad Rajabia* & Abdolali Fayyaz b
Abstract

Micropowder injection moulding (μPIM) is an ideal alternative for miniaturization of parts because of its ability to produce complex micro-geometries at low manufacturing cost. Utilizing bimodal powder mixtures in feedstock can increase packing density and densification of parts fabricated via μPIM. This study investigated the feedstock consists of nano-micro 316L stainless steel powder-and polyethylene glycol-based binder system. The flowability of different feedstocks was evaluated using rheological parameters, including critical powder volume concentration (CPVC), melt viscosity, activation energy, and rheological index. Results showed that mixing nanopowders with micropowders increases CPVC from 67.66 vol.% (pure micropowder) to 78.33 vol.%. The nano-micropowder feedstock showed viscosity below 45 Pa·s and shear rate in the range of 102 s−1 to 105 s−1, which are suitable for the μPIM process. The determined flow index values ranged from 0.25 to 0.76, and the reduced n values at high temperature with the addition of nanopowder indicated a possible increase in shear-thinning behavior. A defect-free microsample was obtained at an injection temperature of 85°C with sintering at 1200°C. Using the nano–micro bimodal powders, the hardness of the obtained samples also increased from 182 HV to 221 HV, with strength of 501 MPa, which is higher than that of the sample obtained with the use of micropowder only (435 MPa).

Keywords: Micropowder injection moulding; Rheology; Flow behavior; Flow index; Nanopowder

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-07
229-241
8. Machine Learning in 3D Space Gesture Recognition

Veronica Naosekpam* & Rupam Kumar Sharma
Abstract

The rapid increase in the development of robotic systems in a controlled and uncontrolled environment leads to the development of a more natural interaction system. One such interaction is gesture recognition. The proposed paper is a simple approach towards gesture recognition technology where the hand movement in a 3-dimensional space is utilized to write the English alphabets and get the corresponding output in the screen or a display device. In order to perform the experiment, an MPU-6050 accelerometer, a microcontroller and a Bluetooth for wireless connection are used as the hardware components of the system. For each of the letters of the alphabets, the data instances are recorded in its raw form. 20 instances for each letter are recorded and it is then standardized using interpolation. The standardized data is fed as inputs to an SVM (Support Vector Machine) classifier to create a model. The created model is used for classification of future data instances at real time. Our method achieves a correct classification accuracy of 98.94% for the English alphabets’ hand gesture recognition. The primary objective of our approach is the development of a low-cost, low power and easily trained supervised gesture recognition system which identifies hand gesture movement efficiently and accurately. The experimental result obtained is based on use of a single subject.

Keywords: Human Computer Interaction; Gesture Recognition; Machine Learning; Support Vector Machine; Accelerometer.

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-08
243-248
9. The Load Performance of Multi-Level Alternating Voltage Provided by Upgrade Effect

Erol CAN
Abstract

In this paper, the applications of the multi-level inverter with a partial inductor are investigated on different loads. The operation of the inverter is given according to different conditions of the circuit at the six-part duty times. Mathematical equations for the inverter are forming according to the load which is resistive (R), inductive (L), and Capacitive (C) in serial connection. After describing the circuit structure, Matlab SIMULİNK also simulates the circuit for loads that are RLC, and a single-phase asynchronous motor. While the voltage and current measurements for the RLC load are performed; measurements of the main winding current, auxiliary winding current, electromagnetic torque, speed are made on the asynchronous motor. RLC loads are operated at high current values such as 297A in order to examine the suitability of the proposed system for systems that may require high current. When the current harmonic distortions of RLC loads are observed, the distortion values are acceptable values that are lower than % 5 that is international standards of the IEEE. In another hand, despite the voltage is insufficient for supplying the motor at the motor application, the voltage is upgraded with the boost effect of the inverter. So, the voltage is both a multilevel and sufficient. According to the obtained results, it is shown that multi-level inverter design has been successfully performed by using partial inductor source.

Keywords: Partial inductor source; different working times; the upgrade effect of the inverter

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-09
249-259
10. A Framework for Six-Sigma Implementation in Rubber Manufacturing Industry – An Innovation between DMAIC Cycle and Quality Improvement Tools

Mohd Nizam Ab Rahmana, Muhammad Zeeshan Rafiqueb*, Zamri Darusc * & Muhammad Saad Amjadb
Abstract

Quality improvement tools are commonly utilised by the industries to attain quality products and benefits like reduction in scrap cost and wastes. In order to achieve the proper implementation of quality tools, a theoretically developed framework inclusive of six-sigma DMAIC (Define, Measure, Analyse, Improve & Control) cycle is required. Also, the quality tools associated at each stage has thoroughly implemented on a case study which carries a real-time issue related to the quality products production. The issue has thoroughly resolved through the right application of quality tools like Failure Modes and effects analysis (FMEA) on the compression moulding technique utilised for the production of Rubber Valve Sleeve Liner (RVSL) under the umbrella of DMAIC cycle. The benefits achieved are 23.1% reduction in scrap rate, 63.8% reduction in Delivery on time (DOT) with savings gained almost RM26,880/month. The relationship between DMAIC cycle and quality tools for quality improvements under the platform of lean six sigma which is highly beneficial for academicians, practitioners and engineering managers working in this field with a limitation of implementation only in the rubber manufacturing industry. In future, the developed framework should be implemented in some other manufacturing industries.

Keywords: Lean Six Sigma; Rubber Manufacturing; DMAIC Cycle; Quality Improvement

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-10
261-273
11. Velocity Modelling for Pipeline Inspection Gauge
(Pemodelan Halaju Tolok Pemeriksaan Talian Paip Gas)

Low Zi Lia, Masli Irwan Roslia,b,* & Dedikarni Panuhc
Abstract

Pipeline inspection gauges (PIGs) apply in oil and gas industries, particularly in cleaning, dewatering, and inspecting pipelines. Also, both the speed and driving pressure for the PIGs operation are deduced basis on the guesswork or experience. In this study, the dynamic behaviour of PIGs in gas pipelines is investigated. The dynamic differential equations of PIG velocity are used to calculate the motion of models Solghar and Nieckele. Differential and other conditional equations are simultaneously solved by using the ODE45 built-in function of the MATLAB® software. Generally, the dynamic motion of PIGs depends on the differential pressure of the fluid and can be affected by other parameters, such as bypass area and frictional force. Therefore, we further examine and consider these parameters in modelling. We validate the modelling results by comparing them with the experimental results obtained by a PIG manufacturing company. Results show that the Solghar model is more suitable than Nieckele model in operating condition selections. The increasing bypass area and frictional force reduce the movement speed of the PIG because of the decrease in the pressure difference between the PIGs. Subsequently, a graphical user interface is created and customised in MATLAB® to automate the calculation of PIG velocity.

Keywords: pipeline inspection gauge; modelling; velocity; MATLAB

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-11
275-280
12. Geo-Polymer Binder as Portland Cement Alternative: Challenges, Current Developments and Future Prospects

Abubakar Ndagia,* & Mohd Saleh Jaafara
Abstract

Ordinary Portland Cement (OPC), a material which built the world is now devastating it. Environmental impact has raised concerns over its continued usage while its multifaceted problems are also biting the production companies hard. Hence, alternative geopolymer binder has demonstrated excellent properties to stand ordinary Portland cement even though it is still being faced with technical drawbacks. Therefore, these paper reviews attempt made on improving discoveries and understanding about proper implementation of geopolymer binder. The geopolymer binder is curable at ambient temperature by the use of Fly Ash/Ground Granulated Blast Furnace Slag (GGBS) blend. This has been an alternative have been discovered for cheaper activating solutions rather than the expensive Sodium Hydroxide/Sodium Silicate solution. However, various of chemical composition known as Supplementary Cementitious Materials (SCMs) still an issues to fabricate a geopolymer binder.

Keywords: Geopolymer; Green Concrete; Ordinary Portland Cement

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-12
281-286
13. Pattern Recognition for HEV Engine Diagnostic using an Improved Statistical Analysis
(Pengiktirafan Corak untuk Diagnosis Enjin HEV menggunakan Analisis Statistik yang Telah Ditambahbaik)

Nor Azizi Ngatiman* & Mohd. Zaki Nuawi
Abstract

Detecting early symptoms of engine failure is a crucial phase in an engine management system to prevent poor driving performance and experience. This paper proposes a Hybrid Electric Vehicle (HEV) engine diagnostics using a low-cost piezo-film sensor, an analysis with improved statistical method and verification by a Support Vector Machine (SVM). The current engine management system is unable to evaluate the performance of each cylinder operation. Eventually, it affects the whole hybrid vehicle system, particularly in the mode of charging and accelerating. This research aims to classify the combustion to monitor the condition of sparking activity of the engine by using the Z-freq statistical method. Piezo-film sensors were mounted on the Internal Combustion Engine (ICE) wall of each hybrid vehicle for vibration signal measurements. The engine runs at different speeds, the vibration signals were then recorded and analysed using the Z-freq technique. A machine learning tool referred to as Support Vector Machine was used to verify the classifications made by the Z-freq technique. A significant correlation was found between the voltage signal and calculated Z-freq coefficient value. Moreover, a good pattern was produced within a consistent value of the engine speed. This technique is useful for the hybrid engine to identify different stages of combustion and enable pattern categorisation of the measured parameters. These improved techniques provide strong evidence based on pattern representation and facilitate the investigator to categorise the measured parameters.

Keywords: Hybrid engine diagnostic; Pattern recognition; Piezo-film sensor; Statistical signal analysis; Z-freq

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-13
287-294
14. Drying of Instant Coffee in a Spray Dryer
(Pengeringan Serbuk Kopi Segera dalam Pengering Sembur)

Nur Tantiyani Ali Othmana, b* & Muhammad Elmi Fahmi Mohd Razalib
Abstract

Instant coffee is a popular beverage around the world and has been recognized for shorter preparation time and longer shelf life compared to brewed coffee. The production of instant coffee powder through the drying process requires lots of attention to provide the best quality of coffee to the consumer. Most of the instant coffee powder has been produced either by freeze-drying or spray drying. However, the drying spray showed some advantages in case of shorter drying time, ability to handle in a large capacity, and continuous production of coffee powder compared. The objective of this study is to identify the affecting factors in achieving a high quality of coffee production in the drying process. The initial concentration of coffee extract is between 30-42 wt.% were fed by the atomizer. Also, the spray drying chamber with the inlet air temperature of 423.15 K to 573.15 K. The pressure was set at 52 bar to obtain the best drying quality of the coffee production. The simulation results show with the air temperature of 423.15 K, the pressure of 52 bar and the initial extract concentration of 42% are the best conditions of drying coffee using the spray drying method. Also, the velocity distribution flattened as the flow proceeds downstream. As well, the vapour concentration distribution flattened further down the chamber so that the drying air leaving the drying chamber has almost a uniform moisture distribution.

Keywords: Instant coffee; spray dryer; Ansys Fluent; drying; moisture content; evaporation rate

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-14
295-301
15. Heavy Metals Detection from Contaminated River Using Molybdenum Reducing Enzyme
(Pengesanan Logam Berat daripada Sungai Tercemar Menggunakan Enzim Penurun Molybdenum)

Nurlizah Abu Bakar, Ahmad Razi Othman* & Mohd Yunus Shukor
Abstract

Heavy metals contamination in Malaysia River has attracted concern among Malaysians. The issue arises when the Department of Environmental Malaysia in 2015 claimed the number of polluted river has increased from year 2000 to 2015. Therefore, the monitoring method is required in order to screen the polluted area. Current monitoring systems involved analytical methods such as Atomic Absorption Spectrophotometer (AAS) and Inductively Coupled Plasma (ICP) are costly, thus, the development of effective method and cost effective in screening heavy metal contamination is required. Molyhdenum-reducing enzyme has a potential to detect heavy metals contamination in river water samples. The enzyme extracted from locally isolated bacteria labeled as Bacilus sp. strain A.rzi was partially purified based on ion exchange chromatography using High Performance Liquid Chromatography (HPLC). The screening for heavy metals inhibition towards Mo-reducing enzyme was based on colorimetric analysis. Data for IC50 determined using statistical analysis (one phase decay plot) showed. Significant inhibition with three heavy metals (copper, lead and mercury) towards Mo-reducing enzyme. Copper showed the highest IC50 value of 0.25 mgL-1 followed by mercury and lead at 0.35 mgL-1 and 0.49 mgL-1 respectively. Screening for river water samples showed that Mo-reducing enzyme positively reacted to heavy metals in water samples. The Colorimetric based assay also showed heavy metals present in river water samples had inhibited Mo-reducing enzyme activity. The enzyme could reduce heavy metals to form molybdenum blue and was observed during reaction. Due to this unique feature, Mo-reducing enzyme can be proposed as a bioassay method for detecting heavy metal in river samples.

Keywords: Heavy metals; Bioassay; Molybdenum Blue; Molybdenum reducing enzyme

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-15
303-308
16. Transformation in the Architectural Identity of Palaces
(Transformasi dalam Identiti Senibina bagi Istana)

Nurul Alia Ahamada*, Zahari Zubira, Prince Favis Isipa & Nor Hayati Hussainb
Abstract

The establishment of the first National Palace in Malaya in 1957 reflects the transformation in the identity of palace architecture. Traditional palace architecture has developed from society’s traditional way of life, as well as the materials and techniques of local construction. However, in the 1950s, significant changes could be seen in the lifestyle, politics, economics and many other areas in Malaya due to modernisation. The changes in the political system and people’s values have influenced the traditional palace architecture during the 1950s. This research aims to highlight the palace’s architecture transformation as direct consequences of changes in the identity of the state and nation. The research employs interpretive historical methodology, with the first National Palace as the case study. The study concluded that the architecture of the first National Palace reflects an image based on the contemporary values of the local community, which meet the political aspiration of a modern democratic government at that time. These findings will contribute to the understanding of the changes in the traditional social contract between the rulers and the people, and the selection of modern architecture as an identity of the country’s current government.

Keywords: Transformation; Architecture; Identity; Traditional Palace; National Palace

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-16
309-316
17. The Effect of the Rheocast Process on the Microstructure and Mechanical Properties of Al-5.7Si-2Cu-0.3Mg Alloy
(Kesan Proses Pembentukan Tuangan Reo terhadap Sifat Mikrostruktur dan Mekanikal Aloi Al-5.7Si-2Cu-0.3Mg)

Mnel A H Abdelgneia,b,c*, Mohd Zaidi Omarb, Mariyam Jameelah Ghazalib Mohamed A. Gebrilb & M N Mohammed
Abstract

This study shows the results of an experimental investigation of semisolid rheocasting of Al-5.7Si-2Cu-0.3Mg alloy using a cooling slope (CS) casting technique. However, the challenge is to determine process parameters of the CS process to get a desirable microstructure in the semisolid feedstock material. cooling slope technique was employed to create feedstock material for thixoforming under an argon gas atmosphere, where on an inclined plate that was fixed at a 60° slope angle, molten alloy is poured at different temperatures of 640°C, 650°C and 660°C at lengths 300, 400 and 500 mm. Examination the microstructure with optical microscope observed that the microstructure of conventionally cast alloy presented coarse and dendritic primary α-Al phase, whereas rheocast alloy included fine and nondendritic primary α-Al phase with homogeneous distribution of eutectic phase. The best CS processing condition has been identified for optimum pouring temperature of 650°C and the slope length of 400 mm as average globular grain size of around 31.67 ± 3 μm and a shape factor of about 0.66 ± 0.09 were obtained. The mechanical properties of conventional cast alloy were enhanced by the CS casting process. The ultimate tensile strength, the yield strength and elongation of the rheocast alloy were increased by 10%, 12% and 22% respectively compared to the conventional cast alloy. due to a reduction in shrinkage and porosity of the microstructure of the CS alloy.

Keywords: Al-Si alloy; Cooling slope process; Microstructure; Mechanical properties

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-17
317-326
18. Role of Graphene Oxide in Support Layer Modification of Thin Film Composite (TFC) Membrane for Forward Osmosis Application
(Peranan Oksida Grafin dalam Pengubahsuaian Lapisan Sokongan Membran Komposit Filem Nipis (TFC) untuk Aplikasi Osmosis ke Hadapan)

Wan Nur Syuhada Wan Ata, Ang Wei Lunb & Abdul Wahab Mohammadb*
Abstract

In this work, the effect of graphene oxide (GO) incorporation into the membrane support layer towards the performance of thin-film composite (TFC) membrane was investigated. The support layer was fabricated by phase inversion method with the incorporation of GO as hydrophilic nanoparticles. Next, the active polyamide layer was formed on the membrane support layer via interfacial polymerization between trimesoyl chloride (TMC) and m-Phenylenediamine (MPD). The cross-section images from Field-Emission Scanning Electron Microscope (FESEM) showed the presence of active polyamide layer on the surface of TFC membrane while the FTIR results indicated the existence of bands associated with the amide linkages. The initial study showed that an optimal amount of GO (0.5 wt%) incorporation into the polymer substrate resulted in favourable improvement in TFC membrane performance. The physical and chemical properties of GO helps in enhancing the water transport through the membrane polymer matrix and thus contributing to higher permeate flux. The TFC-FO membrane incorporated with GO showed 44% improvement in terms of water flux (3.72 compared to 2.09 Lm-2 h-1 for pure PSf membrane) and minimal improvement in reverse solute diffusion (0.02 compared to 0.03 g m-2 h-1 for pure PSf membrane). Thus, this study showed that small addition of GO nanoparticles into the membrane support layer leads to an increase in performance of TFC membrane for FO application.

Keywords: Graphene Oxide; Support Layer; Water Permeation; Thin Film Composite; Forward Osmosis

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-18
327-334
19. Inexpensive Current-Voltage System with Electronically-Controlled Resistance under Xenon Arc Light for Solar Cell Efficiency Measurements
(Sistem Arus-Votan yang Murah dengan Rintangan Terkawal-Elektronik di bawah Lampu Xenon Arka untuk
Pengukuran Kecekapan Sel Suria)

Mukhlis Mokhtar, Samir Ahmad, Suhaila Sepeai*, Norizam M. Daud & Saleem H. Zaidi
Abstract

Crystalline silicon solar cell efficiency is required in order to accurately determine its performance and evaluate the fabrication process. Extensive automation has led to development of expensive instrumentation. In this study, simple, inexpensive method for measuring solar cell efficiency is reported. A controllable direct current (dc) illumination intensity method based on low power xenon arc lamps was designed and constructed. Low resistance electrical contacts were formed with conventional front surface probes and back surface Au-plated metal plate with vacuum attachment. In order to measure current-voltage (I-V) response, variable resistance approach was chosen. Commercially available, low cost electronic loads power supply is used to precisely vary resistance while measuring cell voltage and current. The resistance is controllably varied from a short circuit to an open circuit position on the I-V curve while measuring cell voltage and current. Plotting current as a function of voltage generates the characteristic solar cell I-V response. Solar cell efficiency measurements were recorded and plotted using LabVIEW program. The light intensity was varied by increasing number of high intensity discharge (HID) 50 W from 1 to four in order to vary respective illumination intensities from 330 to 1200 W/m2 range. The variation in light intensity was aimed at investigation of the electronic loads power supply at low and high currents. This I-V tester has been applied to different types of solar cell to validate its performance. Solar cells measured as part of this study included commercial silicon solar cell and laboratory solar cells with phosphorus oxytrichloride (POCl3) and phosphoric acid (H3PO4) emitter formation. This I-V measurement system for commercial cell exhibited an efficiency of 15.83% and efficiency of 16.2% and 13.3% for solar cells with POCl3 and H3PO emitters.

Keywords: Current-Voltage; DC Light; Electronic Load; Solar Cell; Testing

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-19
335-340
20. Prototype Development of a Smart Voice-Controlled Audio System B9ased on the Raspberry Pi Platform
(Pembangunan Prototaip Sistem Audio Pintar Kawalan-Suara Berasaskan Platform Raspberry Pi)

Weng Thong Kuana & Muhammad Faiz Bukhoria,b,* & Abdul Halim Ismail
Abstract

We report a prototype audio system that can be controlled by means of voice commands. The operations of this audio player – such as song playback and volume control – can be effectively controlled by verbal commands alone without requiring any button-press or dial-turn, enabling a user to operate it with full hands. This feature could be particularly useful in situations when the user’s view and attention are pre-occupied, as in the case of driving or cycling. A voice-command device also has the advantage of a smaller form factor and simpler product casing, due to fewer dials and buttons. While there are a wide variety of commercial audio systems, only very limited few allow voice-control operations. This voice-controlled audio system is low-cost, open-source, and capable of “smart” features that include notifying weather forecasts, automatic volume control, and automatic shutdown. Its platform is the single-board computer Raspberry Pi, which runs speech-to-text processes that record and transcribe a given voice command, such as “Play music” and “Volume up.” The Raspberry Pi also connects to cloud-based services – and upon voice requests – can check and tell real-time information such as date, time, and weather. The system’s average response time to a given voice command was measured to be about 5 seconds. A simple circuit of LED indicators was also designed to prompt users to give voice commands at the right window of time, therefore improving system responsiveness and overall user experience. This prototype can be extended to voice-control other appliances in an integrated smart home environment.

Keywords: Audio system; Voice command; Voice recognition; Consumer electronics; Raspberry Pi; Prototyping

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-20
341-348
21. Indeks Pembangunan Lestari Alam Sekitar: Kriteria dan Cabaran Pelaksanaannya dalam Pengurusan Sisa Pepejal Perbandaran di Malaysia
(Index of Environmental Sustainabilty: Criteria and Challenges of Implentation on Malaysian Municipal Solid Waste Management)

Khairunnisa Syarafina Samsudin* & Sohif Mat & Halim Razali & Noor Ezlin Ahmad Basri & Zulkifli Aini
Abstract

The level of hygiene of a developing country represents the level of its MSW management. Apart from the various policies, acts, awareness campaigns and ongoing implementation of recycling programs which aiming to reduce the volume of municipal solid waste to the disposal area as the last location, the use of index principles, is increasingly favoured in sustainable environmental development. In Malaysia, the implementation of sustainable index principles is still low especially in managing municipal solid waste. Hence this research explores the implementation of the principles of sustainable environmental development index, recommending sustainability indicator based on national development plans and the key challenges in implementing these principles in the management of solid waste in Malaysia. Content analysis techniques were used in this study where reading materials such as journals, thesis reports, research projects, and research reports were used. The results of the analysis have identified the various criteria in existed indices that can be applied in managing municipal solid waste in Malaysia. In addition, the challenges of implementing the sustainable development index in managing municipal solid waste in Malaysia have also been discussed. The results of this study are expected to be used by policy makers and all stakeholders.

Keywords: Municipal solid waste management; Green index; Sustainable development; Malaysia, Indicator

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-21
349-356 
22. Kajian Perbandingan Penggunaan Model Rangkaian Saraf Tiruan dan Model Penyesuaian Logik Kabur untuk Meramal Modulus Elastik Turapan Boleh Lentur
(A Comparative Study of Artificial Neural Network and Adaptive System Network Model Neuro-Fuzzy Models to Predict Flexible Pavement Layer Moduli)

Mohammad Izzulhanif Mohd Arifa, Asmah Hamima, Ahmad Nazrul Hakimi Ibrahima, Faridah Hanim Khairuddina,b,
Nor Azliana Akmal Jamaludinc & Nur Izzi Md. Yusoffa*
Abstract

This research was conducted to investigate the suitability of using two models; namely the artificial neural network (ANN) and adaptive system network model Neuro-Fuzzy (ANFIS) methods to predict the flexible pavement layer moduli. The falling weight deflectometer (FWD) data obtained from the Butterworth–Kulim Expressway (BKE) in year 2011 were used to test the models. The ANN and ANFIS models have been trained and tested continuously using different parameters until the optimum output is obtained. Thereafter, a validation process has been carried out to test the ability of whole models by calculating the coefficient of determination (R2), the mean absolute error (MAE), the mean squared error (MSE) and root mean squared error (RMSE). A total of 270 data sets have been used to develop the models. Based on the analysis conducted, it was found that both models are able to predict well the flexible pavement layer moduli(R2 > 0.90). However, a further comparison suggested that the ANFIS model yield a higher precision compared to the ANN model, with lower MAE, MSE and RMSE values. Therefore, it can be inferred that the neural network models have an excellent potential to replace the existing analytical and empirical models in predicting the flexible pavement layer moduli.

Keywords: Artificial neural network; Adaptive system network model neuro-fuzzy; Falling weight deflectometer; Modelling

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-22
357-366
23. Analisa Laporan EIA dalam Aspek Kajian Hakisan Tanah dan Sedimentasi bagi Projek Perumahan
(Analysis on EIA Report In Terms of Soil Erosion and Sedimentation Study for Housing Project)

Abdul Rahman Mahmud* & Zaini Sakawi
Abstract

Soil erosion and sedimentation control has become one of the challenges in the implementation of EIA projects especially for housing construction activities. Failure to implement adequate erosion control measures at the project site would affect the quality of river water. To ensure adequate control of soil erosion and sedimentation the EIA reports submitted should achieve minimum standards of impact assessment and control measures as well as good quality. This study was conducted to evaluate the quality of the EIA report in terms of soil erosion and sedimentation aspect. The EIA review package has been prepared by referring to the guidance document on soil erosion and sedimentation. A total of 21 EIA reports for housing projects from 2013 to 2015 in Selangor have been analyzed. The results show that 18 of the EIA reports complied with 50% of the requirements that set in the guidelines, while the quality aspect of the EIA report shows that only 7 reports have achieved satisfactory level. This study identified there are three major weaknesses in the EIA report for housing projects. Firstly; the description of earth work planning are not thoroughly explained, secondly; the weaknesses in the descriptions of the project options and third; the weaknesses in the Land Disturbance Pollution Prevention and Mitigation Measures (LDP2M2) conceptual plan which is not plan in stages. The skills and expertise of EIA consultant and also EIA review officer is need to be improved. It is to ensure the quality of EIA report and the compliance to the EIA guidelines can be achieved. The EIA review packages which developed in this study could be used by the consultants to evaluate the adequacy of the EIA content as a self-assessment practice.

Keywords: EIA; the quality of EIA reports; EIA effectiveness; soil erosion and sedimentation; EIA review package; the EIAprocedure in Malaysia
Artikel

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-23
367-373 
24. Kajian Persepsi Arkitek terhadap Pelaksanaan Bumbung Hijau di Malaysia: Faedah, Halangan dan Cadangan
(A Study on the Perception of Architects on The Implementation of Green Roofs in Malaysia: Benefits, Obstacles and Recommendatiosn)

Mohd. Hafizzudin Md. Zahira, Chin Ong Woonb, Sudharshan N. Ramanb,*, Mohd. Farid Mohamedb & Zulkifli Mohd. Nopiahc
Abstract

The implementation of a green roof as a sustainable method to reduce the urban heat island effect is still new in Malaysia. Although it has not been tested on a city scale, many studies have found that green roofs can balance the impact of urbanization by improving environmental quality. Its low usage in Malaysia is due to various factors, such as cost and the lack of awareness among the construction industry players. This study aims to identify the perceptions of local architects towards the implementation of green roof and its benefits, obstacles and recommendations to overcome the challenges in implementation. Questionnaire survey were used to determine the views of local architects, on ten benefits, nine obstacles of green roof implementation and eight recommendations to overcome the green roofs obstacles. The results indicated that the most important green roof benefit was minimizing the urban heat island effect (N = 8.14). Meanwhile, the weakest green roof benefit was increasing the roofing thermal insulation (N = 3.73). The most significant obstacle of green roof application was the constraint of implementation by the client (N = 4.22), with the weakest obstacle was inadequacy in the confidence of the architect towards the benefits of the green roof (N = 2.62). In addition, the most significant recommendation to overcome its implementation obstacles was enhancing the incentive to green roof operators (N = 4.37), while the weakest recommendation is by bringing in foreign expertise and technology transfer (N = 3.65). The findings of the study will facilitate in promoting the implementation of green roofs in Malaysia and enhancing the contribution of the green roof to the interior and exterior environment of buildings.

Keywords: Green roof; Architect; Sustainable development; Perception

DOI : dx.doi.org/10.17576/jkukm-2019-31(2)-24
375-381