UniMAP RIS :: Browsing Publications 2019 by Issue Date

Publication

Performance of the hybrid growth sequencing batch reactor (HG-SBR) for biodegradation of phenol under various toxicity conditions

( 2019-01-01)

Yusoff N.

;

Ong S.

;

Ho L.

;

Wong Y.

;

Saad F.

;

Khalik W.

;

Lee S.

Hybrid growth microorganisms in sequencing batch reactors have proven effective for treating the toxic compound phenol, but the toxicity effect under different toxicity conditions has rarely been discussed. Therefore, the performance of the HG-SBR under toxic, acute and chronic organic loading can provide the overall operating conditions of the system. Toxic organic loading (TOL) was monitored during the first 7 hr while introducing 50 mg/L phenol to the system. The system was adversely affected with the sudden introduction of phenol to the virgin activated sludge, which caused a low degradation rate and high dissolved oxygen consumption during TOL. Acute organic loading (AOL) had significant effects at high phenol concentrations (600, 800 1000 mg/L). The specific oxygen uptake rate (SOUR) gradually decreased to 4.9 mg O2/(g MLVSS·hr) at 1000 mg/L of phenol compared to 12.74 mg O2/(g MLVSS·hr) for 200 mg/L of phenol. The HG-SBR was further monitored during chronic organic loading (COL) over 67 days. The effects of organic loading were more apparent at 800 mg/L and 1000 mg/L phenol concentrations, as the removal range was between 22%–30% and 18%–46% respectively, which indicated the severe effects of COL.

Publication

An Overview of Unique Metal Oxide Nanostructures for Biosensor Applications

( 2019-01-01)

Anthony L.S.

;

Perumal V.

;

Mohamed N.M.

;

Saheed M.S.M.

;

Gopinath S.C.B.

Metal oxide nanostructures have recently garnered much recognition because of their exceptional electrical, optical and molecular properties that provide a fascinating platform for the development of biosensors. Till recent years, various methods and techniques such as chemical precipitation, electrodeposition and hydrothermal treatment have been utilised to fabricate metal oxide-based biosensors with high sensitivities and low detection limits. However, a number of these fabricated devices are irreversible and have low sensitivities. Therefore, more efficient and reliable biosensing technologies need to be developed. Biosensors are usually defined as an analytical equipment that consists of a biological recognition component integrated to a transducer and signal processing unit that converts, amplifies and displays biochemical activity into a measurable signal. The goal of this bioelectrical combination is to detect pathogenic and physiological molecules in the food or body for the early detection as well as treatment of diseases using the high sensitivity and selectivity of biological sensing. We review here some of the main strategies used in the fabrication of metal oxide nanostructures, including the advancements in biosensors based on metal oxides and evaluate their properties with the aim of motivating greater interest in improving the development of biosensors for medical diagnosis.

Publication

Fabrication and thermoelectric property of Bi0.88Sb0.12/InSb eutectic alloy by melt spinning and spark plasma sintering

( 2019-01-01)

Norizan M.N.

;

Ohishi Y.

;

Kurosaki K.

;

Muta H.

In the present study, self-assembled submicrometer-sized composite structure of bismuth-antimony (BiSb) alloy and indium antimonide (InSb) were fabricated by melt-spinning (MS) technique and spark plasma sintered (SPS) process with the eutectic composition. The power factor reached 2.6 mW/mK2 at 300 K. The thermal conductivity decreased by 35% compared with the BiSb alloy. The results suggest that this MS-SPS procedure is promising for reducing the thermal conductivity with maintaining the electrical properties.

Publication

Design and analysis of dedicated Real-time clock for customized microcontroller unit

( 2019-01-01)

Alias M.

;

Mohyar S.

;

Isa M.

;

Harun A.

;

Jambek A.

;

Murad S.

In this paper, a Real Time Clock (RTC) system for a dedicated microcontroller is proposed to provide the customized microcontroller its own time and date system. The RTC is developed using Verilog Hardware Description Language (HDL) and simulated using Synopsys software. This RTC is developed with standard Advance Peripheral Bus (APB) to be interfacing with the microcontroller through Advanced Microcontroller Bus Architecture (AMBA). This RTC will be used as an on-chip RTC in the microcontroller system to provide precise time and date which can be used for various applications. The basic architecture of RTC, APB standard for interfacing the RTC with AMBA bus, and the result in term of RTL, waveform, and layout will be discussed in this documentation. For this research, the part covered is on the logic part of the RTC that is bus interface, register, frequency divider and counter.

Publication

A Ku-band SIW Six-port

( 2019-01-01)

Tan G.S.

;

Ibrahim S.Z.

;

Karim M.N.A.

;

Dewani A.A.

;

Razalli M.S.

This paper shows a compact fully integrated six-port Substrate Integrated Waveguide (SIW) operating at Ku-Band frequency range. The SIW six-port is formed by combining two SIW power dividers and two SIW couplers, having the benefit of no additional termination is required as this topology has no excessive port. To achieve the optimized design of the six-port, both of the key components; power divider and coupler are primarily designed, fabricated, and measured individually. Y-junction topology is employed on the power divider structure to achieve a compact size. In turn, the coupling coefficient of the two output ports of the SIW coupler are improved by shifting the position of a row of several vias located at the side wall center closer to the side wall. The simulated six port performance provides an advantage of wide bandwidth within Ku-Band across 13 to 17 GHz with a return loss better than 12 dB and transmission coefficient of 7±1.5 dB. The simulated and measured results show good agreement thus validating the prototype. The SIW six-port can find its application in designing a six-port.

Publication

Hydrocephaly Analysis Supported by Computerized Tomography and Nuclear Magnetic Resonance

( 2019-01-01)

Zhang T.

;

Zhou Y.

;

Su G.

;

Shi D.

;

Gopinath S.C.B.

;

Lakshmipriya T.

;

Li S.

Hydrocephalus is widely known as "hydrocephaly" or "water in the brain," a building up of abnormal cerebrospinal fluid in the brain ventricles. Due to this abnormality, the size of the head becomes larger and increases the pressure in the skull. This pressure compresses the brain and causes damage to the brain. Identification by imaging techniques on the hydrocephalus is mandatory to treat the disease. Various methods and equipment have been used to image the hydrocephalus. Among them, computerized tomography (CT) scan and nuclear magnetic resonance (NMR) are the most considered methods and gives accurate result of imaging. Apart from imaging, cerebrospinal fluid-based biomarkers are also used to identify the condition of hydrocephalus. This review is discussed on "hydrocephalus" and its imaging captured by CT scan and NMR to support the biomarker analysis.

Publication

Performance analysis of wavelet transform de-noising technique in partial discharge signal based on various types of mother wavelet via labview software

( 2019-01-01)

Abdullah A.N.

;

Hamadi S.H.K.

;

Isa M.

;

Ismail B.

;

Nanyan A.N.

;

Abdullah A.Z.

;

Irwan Y.M.

Longer service period of insulation system in high voltage has cause major problem to the high voltage equipment which typically due to ageing and deterioration. This will lead to the occurrence of Partial Discharge (PD) and immediate failure of the power system. Nowadays, PD measurement is applied to detect the occurrences of the PD. However, PD measurement has faced problem of unwanted noise in the measured PD signal. Therefore, Discrete Wavelet Transform (DWT) de-noising technique is widely used due to viable and superior characteristic of DWT in rejecting different kinds of noise from measured PD signal. Thus, the performance analysis of DWTde-noising technique based on various decomposition level and different type of mother wavelet, such as Haar, Daubechies, Coiflets, Symlets and Biorthogonal via LabVIEW software were carried out. The performance of denoising technique is analysed based on Mean Square Error (MSE) of the PD signal in order to select the optimum mother wavelet in the de-noising process. Minimum MSE will promising the optimum mother wavelet. Based on the result, bior5.5 wavelet had the lowest MSE value, thus selected as the most optimum for PD de-noising application.

Publication

Solving assembly line balancing problem using heuristic: A case study of power transformer in electrical industry

( 2019-01-01)

Bakar N.A.

;

Ramli M.F.

;

Zakaria M.Z.

;

Sin T.C.

;

Masran H.

Currently, problem in assembly line has created so much attention, particularly in manufacturing area. Similar to this case study as they faced with problems regarding workstation in production line of electrical industry. There exist some cases where workstations in assembly line are experienced with bottleneck and suffered from high idle time. Thus, four heuristic methods are used for minimizing number or workstations and improve the bottleneck problems at the same time. In this case study, LCR, RPW and LPT have successfully minimized the number of workstations from 19 to 16. This solution has affected the layout of assembly line. Different from SPT that manage to improve the bottleneck among workstations by reducing number of workstations from 19 to 17 without changing the line layout. Therefore, both solution has brought an option for an engineer to choose which decision to be used in this assembly line in order to increase the line efficiency.

Publication

Effect of carbonized wood fiber and carbon black loading on density, tensile properties, electrical conductivity and swelling of ethylene vinyl acetate copolymer composites

( 2019-01-01)

Hanif M.P.M.

;

Rozyanty A.R.

;

Kahar A.W.M.

;

Tan S.J.

;

Supri A.G.

Challenges faced to develop conducting polymer composites (CPCs) comprised of poor electro-active stability, control of the mobility, mechanical properties, presentation and concentration of bioactive molecules. Carbonized wood fiber (CWF) with diameter size of 110 µm was successfully produced from waste wood fiber grade B by using conventional furnace machine at 700ºC in air atmosphere for 3 hours. In this study, the effect of CWF and carbon black (CB) on the properties of ethylene vinyl acetate (EVA) composites was studied. The samples were prepared by using brabender plasticoder at temperature 160ºC with rotor speed of 50 rpm. The result indicated that EVA/CB composites showed higher density, void content, tensile strength, and electrical conductivity but lower elongation at break and swelling compared to EVA/CWF composites. Both composites showed increment in density, void content, and electrical conductivity, and reduced tensile strength, elongation at break, and swelling with increasing of filler loading in EVA composites.

Publication

Optimization of AZ80 magnesium alloy anodizing by using Taguchi method

( 2019-01-01)

Jamil A.A.

;

Derman M.N.

;

Azmi S.

In this study, anodizing of AZ80 magnesium alloy by using different parameter were investigated. The Taguchi method was employed to investigate the effect of process parameter, namely anodizing potential, treatment time and electrolyte concentration on corrosion behaviour on anodized AZ80 magnesium alloy. The data were statistically analysed using Minitab software to predict the optimal combination of processing parameter. It was found that the factor that give biggest influence to the corrosion resistance of the anodic film is voltage, followed by Sodium Hydroxide, Sodium Silicate, Sodium Phosphate and finally treatment time. The optimum parameter is achieved by combination of 10 min of treatment time, 30V of potential, and 80, 40 and 30 g/L concentration of potassium hydroxide, sodium silicate and sodium phosphate.

Publication

A remotely controlled sea level compensation system for wave energy converters

( 2019-01-01)

Ayob M.

;

Castellucci V.

;

Abrahamsson J.

;

Waters R.

The working principle of the wave energy converter (WEC) developed at Uppsala University (UU) is based on a heaving point absorber with a linear generator. The generator is placed on the seafloor and is connected via a steel wire to a buoy floating on the surface of the sea. The generator produces optimal power when the translator’s oscillations are centered with respect to the stator. However, due to the tides or other changes in sea level, the translator’s oscillations may shift towards the upper or lower limit of the generator’s stroke length, resulting in a limited stroke and a consequent reduction in power production. A compensator has been designed and developed in order to keep the generator’s translator centered, thus compensating for sea level variations. This paper presents experimental tests of the compensator in a lab environment. The wire adjustments are based on online sea level data obtained from the Swedish Meteorological and Hydrological Institute (SMHI). The objective of the study was to evaluate and optimize the control and communication system of the device. As the device will be self-powered with solar and wave energy, the paper also includes estimations of the power consumption and a control strategy to minimize the energy requirements of the whole system. The application of the device in a location with high tides, such as Wave Hub, was analyzed based on offline tidal data. The results show that the compensator can minimize the negative effects of sea level variations on the power production at the WEC. Although the wave energy concept of UU is used in this study, the developed system is also applicable to other WECs for which the line length between seabed and surface needs to be adjusted.

Publication

Hermite-Gaussian mode in spatial division multiplexing over FSO system under different weather condition based on linear Gaussian filter

( 2019-01-01)

Alshwani S.

;

Fakhrudeen A.M.

;

Ismael M.N.

;

Al-Dawoodi A.

;

Ghazi A.

;

Aljunid S.A.

;

Idrus S.Z.S.

The wireless telecommunication system of hybrid free-space optics (FSO) utilizes a transmission medium of free space to transmit data at high bit rates. However, it is exposed to various effects of noise in different weather conditions. This paper investigates on compensation for atmospheric turbulence in optical communication systems of 10-channels spatial division multiplexing (SDM) over FSO link under different weather conditions based on linear Gaussian filter (LGF). The performance of a 10-channel transceiver system is evaluated in an SDM-FSO link under the clear sky, haze, and rain weather conditions based on Gaussian filter at the receiver. Furthermore, the simulated system has transmitted 100 Gbit/s up for a distance of 12 km FSO in superbly very clear weather condition. Moreover, it is also transmitted 100 Gbit/s up for a distance of 4.2 km FSO during heavy rain and up to 1.1 km distance FSO during heavy haze. The results show that system capacity is effectively increased with the use of SDM that operate at 1550 nm wavelength. Finally, the validation is conducted based on analyzing eye diagrams, Q-Factor and Bit Error Rates

Publication

Using computer simulation to investigate which joint angle changes have the most effect on ball release speed in overarm throwing

( 2019-01-01)

Omar N.

;

Yeadon M.R.

;

King M.A.

Efficient throwing mechanics is predicated on a pitcher's ability to perform a sequence of movements of body segments, which progresses from the legs, pelvis, and trunk to the smaller, distal arm segments. Each segment plays a vital role in achieving maximum ball velocity at ball release. The perturbation of one joint angle has an effect on the ball release speed. An eight-segment angle-driven simulation model of the trunk, upper limbs and ball was developed to determine which joint angle changes have the most influence on ball release speed in overarm throwing for an experienced pitcher. Fifteen overarm throwing trials were recorded, and the joint angle time histories of each trial were input into the simulation model. Systematically replacing each joint angle time history with a constant value showed that overarm throwing was sensitive (≥5 m/s effect on ball release speed) to trunk extension/flexion and upper arm external/internal rotation, and very sensitive (≥10 m/s effect) to forearm extension/flexion. Computer simulation allows detailed analysis and complete control to investigate contributions to performance, and the key joint angle changes for overarm throwing were identified in this analysis.

Publication

A Fuzzy-Based Angle-of-Arrival Estimation System (AES) Using Radiation Pattern Reconfigurable (RPR) Antenna and Modified Gaussian Membership Function

( 2019-01-01)

Jais M.I.

;

Thennarasan Sabapathy

;

Muzammil Jusoh

;

R Badlishah Ahmad

;

Jamaluddin M.H.

;

Kamarudin M.R.

;

Ehkan P.

;

Murukesan Loganathan L.

;

Soh P.J.

Angle-of-arrival (AOA) estimation is an important factor in various wireless sensing applications, especially localization systems. This paper proposes a new type of AOA estimation sensor node, known as AOA-estimation system (AES) where the received signal strength indication (RSSI) from multiple radiation pattern reconfigurable (RPR) antennas are used to calculate the AOA. In the proposed framework, three sets of RPR antennas have been used to provide a coverage of 15 regions of radiation patterns at different angles. The salient feature of this RPR-based AOA estimation is the use of Fuzzy Inferences System (FIS) to further enhance the number of estimation points. The introduction of a modified FIS membership function (MF) based on Gaussian function resulted in an improved 85% FIS aggregation percentage between the fuzzy input and output. This later resulted in a low AOA error (of less than 5%) and root-mean-square error (of less than 8°).

Publication

Comparison of different wavelength propagations over few-mode fiber based on space division multiplexing in conjunction with electrical equalization

( 2019-01-01)

Al-Dawoodi A.

;

Fareed A.

;

Masuda T.

;

Ghazi A.

;

Fakhrudeen A.M.

;

Aljunid S.A.

;

Idrus S.Z.S.

;

Amphawan A.

Nonlinearities in optical fibers deteriorate system performances and become a major performance-limiting issue. This article aims to investigate the compensation of nonlinear distortions in optical communication systems based on different wavelength propagations over few-mode fiber (FMF). The study adopted Space Division Multiplexing (SDM) based on decision feedback equalizer (DFE). Various transmission wavelength of the FMF system is applied to mitigate the attenuation effect on the system. In this paper, different wavelengths (780, 850 and 1550 nm) are used in SDM. Extensive simulation is performed to assess the attenuation and Bit Error Rate (BER) in each case. The results show that the wavelength of 1550 nm produces higher power and less attenuation in the transmission. Furthermore, this wavelength produces the best distance with less BER compared to 780 nm and 850 nm wavelengths. Moreover, the validations show improvement in BER and eye diagram.

Publication

Parameter adaptation for ant colony system in wireless sensor network

( 2019-01-01)

Nasir H.J.A.

;

Ku-Mahamud K.R.

;

Kamioka E.

The Ant Colony System (ACS) algorithm has been applied in solving packet routing problems in Wireless Sensor Networks (WSNs). Solving these problems is complicated as packets need to be submitted through sensor nodes which are spatially distributed and heterogeneous by nature. Without an effective packet routing algorithm, energy consumption will be increased while network lifetime will be reduced. Most researches are focused on optimizing the routing process by using predefined parameters within a certain range. However, this approach will not guarantee optimal performance. This paper presents the parameter adaptation values for ACS experimental set-up in validating its performance. Possible values of each parameter within a defined range were employed. Experiments were conducted to obtain the best value of each parameter to be used for throughput, energy consumption, and latency. Results of this study can be adopted to achieve optimal performance for the packet routing process.

Publication

Optimization and characterization of magnetite-reduced graphene oxide nanocomposites for demulsification of crude oil in water emulsion

( 2019-01-01)

Wai M.M.

;

Khe C.S.

;

Yau X.H.

;

Liu W.W.

;

Sokkalingam R.

;

Jumbri K.

;

Lwin N.

Oily wastewater from the oil and gas industry negatively affects the environment. Oily wastewater typically exists in the form of an oil-in-water emulsion. Conventional methods to treat oily wastewater have low separation efficiency and long separation time and use large equipment. Therefore, a simple but effective method must be developed to separate oil-in-water emulsions with high separation efficiency and short separation times. Magnetite-reduced graphene oxide (M-RGO) nanocomposites were used as a demulsifier in this work. Magnetite nanoparticles (Fe3O4) were coated on reduced graphene oxide (rGO) nanosheets via an in situ chemical synthesis method. The synthesized M-RGO nanocomposites are environmentally friendly and can be recovered after demulsification by an external magnetic field. M-RGO characterization was performed using X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, field emission scanning microscopy, Raman spectroscopy, and vibrating sample magnetometry. Demulsification performance was evaluated in terms of M-RGO dosage, effects of pH, and brine concentration. The demulsification capability of M-RGO was determined based on the residual oil content of the emulsion, which was measured with a UV-vis spectrometer. The response surface method was used to determine the optimum conditions of the input variables. The optimum demulsification efficiency achieved at pH 4 and M-RGO dosage of 29 g L-1 was approximately 96%. This finding demonstrates that M-RGO nanocomposites are potential magnetic demulsifiers for oily wastewater that contains oil-in-water emulsions. Also, the recyclability of this nanocomposite has been tested and the results shown that it is a good recyclable demulsifier.

Publication

Review of the renewable energy outlook in Saudi Arabia

( 2019-01-01)

Al-Douri Y.

;

Waheeb S.A.

;

Voon C.H.

Currently, existing technologies of energy generation based on fossil fuels and production processes of crude oil usually accompanied by flaring of gases resulted in excessive CO 2 emissions. Kingdom of Saudi Arabia (KSA) national oil consumption is increasing by 7% annually. If this growth rate continues, local demands will be doubled in a decade. This study has covered various renewable energy solutions such as solar thermal hybrid solutions, photovoltaic cells/arrays, and wind turbines. A selection of possible applications of sustainable buildings, wind farming, solar energy, and their futures are discussed. From the crisis viewpoint of energy and environment safety, architectural trends have shifted toward sustainability demands. Energy and ecology were impetus to improve the residents' life quality and health standards. The climate/building correlation has been established to observe the response between both of them. Five distinguished coastal locations in KSA have given the consideration for wind farms, where meteorological data have been recorded since 1970. In contrast to the hot and irksome weather, water misting systems are elaborated to settle a soothing atmosphere. The results are noticed for evaporation and robbing the excessive heat. It is known that health is dependent on clean and unpolluted air, and the pollution has a threat for public health everywhere. So, an induction of renewable energy future has been considered. Gas turbine technology is also discussed as it accounts for about half of the overall capability of the KSA's power generation. Temperature, humidity, and pressure conditions have been accounted as important factors that affect gas turbine performance to produce electricity. An outlook of domestic energy cost is also reviewed. Furthermore, this study has focused on the necessity of maintaining a green and clean environment as well as a climate of lowest dust content. “Reference prices” concept has been clearly comprehended and understood. The contradiction of real opportunities and marginal costs has been explained. An important issue regarding depletion of resources that are depleted exhaustible has been studied. This issue has been tackled and being showed from the starting point. Alternative solutions to provide new energy sources are assumed.

Publication

Squamous Cell Carcinoma Biomarker Sensing on a Strontium Oxide-Modified Interdigitated Electrode Surface for the Diagnosis of Cervical Cancer

( 2019-01-01)

Wang H.

;

Lakshmipriya T.

;

Chen Y.

;

Gopinath S.C.B.

Cervical cancer is a life-threatening complication, appearing as the uncontrolled growth of abnormal cells in the lining of the cervix. Every year, increasing numbers of cervical cancer cases are reported worldwide. Different identification strategies were proposed to detect cervical cancer at the earlier stages using various biomarkers. Squamous cell carcinoma antigen (SCC-Ag) is one of the potential biomarkers for this diagnosis. Nanomaterial-based detection systems were shown to be efficient with different clinical biomarkers. In this study, we have demonstrated strontium oxide-modified interdigitated electrode (IDE) fabrication by the sol-gel method and characterized by scanning electron microscopy and high-power microscopy. Analysis of the bare devices indicated the reproducibility with the fabrication, and further pH scouting on the device revealed that the reliability of the working pH ranges from 3 to 9. The sensing surface was tested to detect SCC-Ag against its specific antibody; the detection limit was found to be 10 pM, and the sensitivity was in the range between 1 and 10 pM as calculated by 3σ. The specificity experiment was carried out using major proteins from human serum, such as albumin and globulin. SCC-Ag was shown to be selectively detected on the strontium oxide-modified IDE surface.

Publication

Investigating the Applicability of Several Fuzzy-Based Classifiers on Multi-Label Classification

( 2019-01-01)

Al-luwaici M.

;

Ahmad Kadri Junoh

;

Ahmad F.K.

: In the last few decades, fuzzy logic has been extensively used in several domains such as economy, decision making, logic and classification. In specific, fuzzy logic which is a powerful mathematical representation has shown a superior performance with uncertainty real-life applications comparing with other learning approaches. Many researchers utilized the concept of fuzzy logic in solving the traditional single label classification problems of both types: binary classification and multi-class classification. Unfortunately, veiy few researches have utilized fuzzy logic in a more general type of classification that is called Multi-Label Classification (MLC). Hence, this study aims to examine the applicability of fuzzy logic to be used with MLC through evaluating several fuzzy-based classifiers on five different multi-label datasets. The results revealed that the utilizing fuzzy-based classifiers on solving the problem of MLC is promising comparing with a wide range of MLC algorithms that belong to several learning approaches and strategies.

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