This research investigated the wear properties of Carbon Nanotube (CNT) filled epoxy polymer and fiber reinforced composites. The CNT/epoxy composites with 0.5 wt% and 1.0 wt% CNT contents were mixed at 50°C for 1 hour at a speed of 400 rpm using mechanical mixer, while woven glass fiber reinforced polymer (GFRP) nanocomposites were fabricated using vacuum bagging technique. The effect of CNT on wear properties was evaluated using dry sliding abrasion wear test that used vitrified bonded silicon carbide as abrasive wheels. The mass loss and specific wear rate curves show that wear properties of epoxy polymer and GFRP composite systems were enhanced when CNT was added. Epoxy polymer and GFRP nanocomposites showed the highest wear resistance when CNT content was 1.0 wt% and 0.5 wt% respectively. The CNT-filled composite showed improvement till up to 78.9 % from its pure system. This suggested that the load transferability between CNT and epoxy was more effective in nanomodified systems than in its pure systems. Therefore, adding CNT improves the wear properties of epoxy polymer and woven GFRP composite.
Exposure to industrial air pollutants is a public health concern particularly in children due to their immaturity of respiratory systems. The distance between their school and home from the industrial area will elevate the risk of airway inflammation among children. This study aims to determine the exposure of Industrial Air Pollutants (PM10, PM2.5, NO2, SO2, and VOCs) and its association with airway inflammation (FeNO) among primary school children in industrial and non- industrial areas in Kemaman, Terengganu. A cross-sectional comparative study was conducted among Malay primary school children in Kemaman, Terengganu. A validated questionnaire was randomly distributed to children to get the background information, respiratory symptoms and exposure history of the children. The assessment of indoor air quality was carried out in each primary school and home using indoor air monitoring equipment. Fractional exhaled nitric oxide (FeNO) was measured using an NIOX MINO device. The results showed a significant difference between concentrations of PM10, PM2.5, NO2, SO2, and VOCs in different classrooms from selected schools and homes of exposed and comparative groups, P
In this study, simulation and optimisation of the purification of bioethanol from an azeotropic mixture was done using the Aspen HYSYS and the Response Surface Methodology (RSM), respectively, to achieve an acceptable bioethanol content with minimal energy use. The objective of this study is to develop the simulation process of bioethanol production from a fermentation effluent. Additionally, the effects of parameters such as solvent temperature, number of entrainer feed stage, mass flow rate and third components of the process for production of bioethanol were studied. As bioethanol is a product of biofuel production, the main challenge facing bioethanol production is the separation of high purity ethanol. However, the separation of ethanol and water can be achieved with the addition of a suitable solvent such as 1,3-butylene glycol (13C4Diol), mixture 13C4Diol and ethylene glycol (EGlycol) and mixture 13C4Diol and glycol ethyl ether (DEG) in the extractive distillation process. For the 13C4Diol mixture, the temperature of entrainer is 90oC with 1500 kg/hr of entrainer rate, while the number of entrainer feed stage is one. The optimum conditions for mixture 13C4Diol and EGlycol require a temperature of entrainer of 90.77oC with an entrainer rate of 1500 kg/hr, while the number of entrainer feed stage is one. Lastly, for optimum conditions for the mixture 13C4Diol and DEG, the temperature of entrainer should be 90oC with an entrainer rate of 1564.04 kg/hr, while the number of entrainer feed stage is one. This study shows that process simulation and optimisation can enhance the removal of water from an azeotropic mixture.
This study focuses on the simulation of ethylene glycol (C2H6O2) – glycerol (C3H8O3) and ethylene glycol (C2H6O2) – calcium chloride (CaCl2) as separating agents in bioethanol production from fermentation effluent. The entire process was simulated using Aspen HYSYS V7.3 software, but the main focus is the extractive distillation where the mixture compounds were utilised. Response Surface Methodology (RSM) was used to optimise the process variables in extractive distillation column with the separating agent ethylene glycol, temperature, solvent to feed molar ratio and reflux ratio. Non-random two-liquid (NRTL) model was used for activity coefficients of mixture from Aspen properties databank. Results show that both mixture compounds values on solvent to feed molar ratio, reflux ratio and reboiler energy consumption were slightly different as separating agent temperature maintained at 80 oC and ethanol composition in distillate was 99.89 mole%. The separating agents show that better ethanolwater separation with lower energy consumption compared with a well-known single compound such as ethylene glycol. Thus, this study is important to improve extractive distillation column operating conditions by studying the effect of mixture compounds as separating agents in bioethanol production.
In this study, oil palm fruit bunch fiber (OPEFB) was used as a secondary filler in HDPE/clay nanocomposites. The composites were prepared by melt compounding, containing high density polyethylene (HDPE), OPEFB fibers, Maleic anhydride grafted polyethylene (MAPE) and four different clay loading (3, 5, 7 and 10 PE nanoclay masterbatch pellets per hundred HDPE pellets). Four OPEFB sizes (180 μm, 250 μm, 300 μm and 355 μm) were added in the composites to investigate its effects on the fracture toughness and impact strength. Fracture toughness of the composites was determined according to ASTM D5045 and single edge notch bending (SENB) was employed during the test while impact tests were performed according to ASTM D256. The effects of alkali treatment were also investigated in this study. The result indicates that the fracture toughness slightly increased as clay loading increased. The highest value of fracture toughness was 0.47 and 1.06 MPa.m1/2 at 5 phr for both types of composites. The presence of OPEFB fiber as a secondary filler in the matrix indicates significant enhancement of fracture toughness up to 133%. However, its impact strength seems to deteriorate with the presence of OPEFB fiber.
Normally, topographic map is produced using aerial photogrammetry. The recent development in aerial photogrammetry is the use of large format digital aerial camera for producing topographic map, however, the cost of the camera is too expensive and many mapping organization around the world could not afford to purchase it. In certain application, there is a need to map small area with limited budget. This issue has been solved by using small format camera (i.e. conventional or digital) to produce digital map. This study concentrates on the use of unmanned aerial vehicle (UAV) for producing digital map. UAV has been widely used in military for reconnaissance, planning, combat, and etc. Today, UAV can be used by civilian for reconnaissance, monitoring, mapping, and others. The objectives of this study are to investigate the capability of UAV in producing digital map and assess the accuracy of mapping using UAV. In this study, a light weight fixed wing UAV was used as a platform and a high resolution digital camera was used to acquire aerial digital images of the study area. The aerial digital images were acquired at low altitude. After capturing the aerial digital images, ground control points and check points were established using GPS. Then the aerial digital images were processed using photogrammetric software. The output of the study is a digital map and digital orthophoto. For accuracy assessment, the root mean square error (RMSE) is used. Based on the assessment, the results showed that accuracy of sub-meter can be obtained using the procedure and method used in the study. In conclusion, this study shows that UAV can be used for producing digital map at sub-meter accuracy and it can also be used for diversified applications.
This paper investigates several asymptotic confidence interval estimates, based on the Wald, likelihood ratio and the score statistics for the parameters of a parallel two-component system model, with dependent failure and a time varying covariate, when data is censored. This model is an extension of the bivariate exponential model. The procedures are investigated via a coverage probability study using the simulated data. The results clearly indicate that the interval estimates, based on the likelihood ratio method, work better than any of the other two methods when dealing with the censored data.
The rapid development of roads and the increasing number of vehicles have complicated road traffic enforcement in many countries due to limited resources of the traffic police, specifically when traffic infraction registration is done manually. The efficiency of the traffic police can be improved by a computer-based method. This study focused on mobile traffic infraction registration system benchmarking which is used to evaluate the server performance under load. The study attempts to provide a clear guideline for the performance evaluation of mobile road traffic infraction registration system, whereby the traffic police can make decision based on them to migrate from the manual-method toward computer-based method. A closed form of benchmark tool was used for the evaluation of the system performance. The tool was configured to imitate ramp scenarios, and statistics were gathered. The server was monitored at different times and works. Contributing factors include bottleneck, traffic, and response time, which are related with criteria and measurements. The system resource was also monitored for the tests.
The effect of solid solution treatment on semisolid microstructure of Zn-22Al with developed dendrites was investigated. Zn-22Al is a zinc-based alloy with aluminium as its main alloying element. Producing Zn-22Al product by semisolid metal processing (SSM) offers significant advantages, such as reduction of macrosegregations, porosity and low forming efforts. Meanwhile, thermal and microstructure analyses of Zn-22Al alloy were studied using differential scanning calorimeter (DSC) and Olympus optical microscope. Solidus and liquidus of the alloy can be determined by DSC analysis. In addition, changes to the microstructures in response to solid solution treatments were also analyzed. The major effort of all the semi-solid technologies is the generation of small and spherical morphologies. Prior to the generation of spherical morphologies, the fine grains should be first produced. The as-cast samples were isothermally held at 315°C, ranging from 0.5 to 5 hours before they were partially re-melted at semisolid temperature of 438°C to produce solid globular grains structure in liquid matrix. The results indicated that a non-dendritic semisolid microstructure could not be obtained if the traditionally cast Zn-22Al alloy with developed dendrites was directly subjected to partial remelting. After solid solution treatment at 315°C, the black interdendritic eutectics were dissolved and gradually transformed into ß structure when the treatment time was increased. The microstructure of the solid solution treated sample changed into a small globular structure with the best shape factor of 0.9 and this corresponded to 40±16µm when the sample was treated for 3 hours, followed by directly partial remelting into its semi solid zone.
The exponential fed-batch cultivation of Bacillus sphaericus UPMB10 in 2 l stirred tank fermenter was performed by feeding the initial batch culture with 14 g l-1 of glycerol according to the algorithm aimed at controlling the specific growth rate (μ) of the bacterium. Very high viable cell count (1.14 x 1010 cfu ml-1), which was four times higher as compared to batch cultivation, was achieved in the fed-batch with a controlled μ at 0.4 h-1. In repeated exponential fed-batch cultivation, consisting of four cycles of harvesting and recharging, a final cell concentration of 1.9 x 1011 cfu ml-1 was obtained at the end of the fourth cycle (46 h). Meanwhile, acetylene reduction of cell samples collected from repeated fed-batch cultivation remained unchanged and was maintained at around 20 nmol C2H2 h-1 ml-1 after prolonged cultivation period, and was comparable to those obtained in batch and exponential fed-batch cultivation. Glycerol could be used as a carbon source for high performance cultivation of B. sphaericus, a nitrogen fixing bacterium, in repeated fed-batch cultivation with high cell yield and cell productivity. The productivity (0.68 g l-1 h-1) for repeated fed-batch cultivation increased about 6 times compared to that obtained in conventional batch cultivation (0.11 g l1 h-1). A innovative method in utilizing glycerol for efficient cultivation of nitrogen fixing bacterium could be beneficial to get more understanding and reference in manipulating the integrated plans for sustainable and profitable biodiesel industry.
The computer, together with Lab View software, can be used as an automatic data acquisition system. This project deals with the development of a computer interfacing technique for the study of Hall Effect and converting the existing automation system into a Web-based automation system. The drive board RS 217-3611 with PCI 6025E card and stepper motor RS191-8340 with a resolution of 0.1mm, was used to move a pair of permanent magnets backward and forward against the sample. The General Interface Bus (GPIB) card interfaces, together with digital nano voltmeter and Tesla meter using serial port RS232 interface, are used for measuring the potential difference and magnetic field strength respectively. Hall Effect measurement on copper (Cu) and tantalum (Ta) showed negative and positive sign Hall coefficient. Therefore, the system has electron and hole charge carriers respectively at room temperature. The parameters such as drift velocity, conductivity, mobility, Hall Coefficient and charge carrier concentration were also automatically displayed on the front panel of Lab View programming and compared with standard value. The Web-based automation system can be remotely controlled and monitored by users in remote locations using only their web browsers. In addition, video conferencing through Net Meeting has been used to provide audio and video feedback to the client.
This study was conducted using crab shells as a biosorbent to remove Cu and Cd with different initial concentrations of 1, 5, 10, 15, and 20 mg/L in a biosorption treatment process. Crab shells were selected as biosorbents due to their abundance in the environment and ready availability as waste products from the market place. This study aimed to determine the ability of Scylla Serrata shells to remove Cu and Cd in an aqueous solution, as well as to provide a comparison of the removal rate between the two metals. The data were incorporated into hydrochemical software, PHREEQC, to investigate the chemical speciation distribution of each heavy metal. The shells of S. serrata were found to have a significant (p< 0.05) ability to remove Cu and Cd following the treatment. After six hours of treatment, the crab shells had removed 60 to 80% of both metals. However, the highest removal percentage was achieved for Cu with up to 94.7% removal rate in 5 mg/L initial Cu concentration, while 85.1% of Cd was removed in 1 mg/L initial solution, respectively. It can be concluded that the shells of S. serrata could remove Cu and Cd better with significant results (p
In this paper, we introduce T-DepExp system to simulate the transitive dependence based coalition formation (CF). It is a multi-agent based simulation (MABS) tool that aims to enhance cooperation between agents through transitive dependence. Previously, the transitive dependence was introduced by An and his colleagues for expressing the indirect dependence between agents in their cooperation. However, it did not receive much attention. Although it has a few problems need to be addressed, we try to propose our own mechanism to increase the efficiency of the transitive dependence based CF. To simulate MAS dependence relationship, we have included two fundamental dependence relationships in this MABS tool, which are AND-Dependence and OR-Dependence. In addition, the architecture of the T-DepExp system is presented and discussed. It allows possible integration of other features such as budget mechanism and trust model. Subsequently, hypothesis for the experiments and experimental setup are explained. The overall system will be demonstrated for its functionality and the experimental results will also be discussed.
The false positive (FP) is an over-segment result where the noncancerous pixel is segmented as a cancer pixel. The FP rate is considered a challenge in localising masses in mammogram images. Hence, in this article, a rejection model is proposed by using a supervised learning method in mass classification such as support vector machine (SVM). The goal of the rejection model which is based on SVM is the reduction of FP rate in segmenting mammogram through the Chan-Vese method, which is initialised by the marker controller watershed (MCWS) algorithm. The MCWS algorithm is utilised for segmentation of a mammogram image. The segmentation is subsequently refined through the Chan-Vese method, followed by the development of the proposed SVM rejection model with different window size as well as its application in eliminating incorrect segmented nodules. The dataset comprised of 57 nodules and 113 non-nodules and the study successfully proved the effectiveness of the SVM rejection model to decrease the FP rate.
An e-learning website is very useful, especially for students and lecturers, as this platform is very efficient for blended learning. Thus, the main objective of this research was to determine the user expectations of e-learning websites of comprehensive universities through localisation based on user preferences. This research showed how users interact with e-learning websites and indicated the patterns that can be used as standard guidelines to design the best e-learning websites. It was found localisation of e-learning websites was scarce and slow interaction with e-learning websites has inconvenienced users. Additionally, too many web objects on the user interface of e-learning websites have a tendency to confuse users. A mixed method approach was used I this study, namely content analysis (qualitative) and localisation (quantitative). Thus, this research contributes to knowledge by guiding users on localising their web objects according to their preferences and hopefully allow for an easy and quick information search for e-learning websites.
In this paper, a micropropagation protocol of sugar palm (Arenga pinnata Wurmb Merr) through callogenesis and somatic embryogenesis was examined. Callus induction frequency and somatic embryogenesis response were dependent on plant growth regulators (PGRs) and genotype. Semi-compact and compact embryogenic calluses were induced from excised immature zygotic embryo (IZE) cultured on semi-solid MS (Murashige & Skoog, 1962) medium supplemented with various concentration and combination of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyl aminopurine acid (BAP). MS medium supplemented with 0.4 mg/L 2,4-D and 0.5 mg/L BAP was found optimum to induce 100% rate of embryogenic calluses and maximum degree of callus formation after 8 and 12 weeks of culture. The incorporation of increased sucrose concentration (60.0 g/L) and 2.0 g/L casein hydrolysate (CH) to the culture medium with similar PGRs composition enhanced the induction of globular somatic embryos (SEs), while addition of silver nitrate (AgNO3) produced SEs of different stages. SEs maturated in MS medium containing 1.0 mg/L BAP and 1.0 mg/L naphthalene-acetic acid (NAA) formed cotyledon-stage embryos. Clonal roots regeneration was obtained on half-strength MS devoid of PGRs after 4 months of culture. Frequent subcultures increased embryogenesis rate favourably.
High uncertainties in aerosol radiative forcing (ARF) arise from inaccurate estimation for aerosol optical depth (AOD) as an input parameter into Santa Barbara Discrete Ordinate Radiative Transfer (SBDART) model. Influence of AOD in ARF at the top of atmosphere (TOA) and surface over Kuching from 2011 until 2015 was investigated using Moderate Resolution Imaging Spectroradiometer (MODIS). Multi plane regression technique was used to retrieve AOD from MODIS (AODMODIS) by using different statistics (mean and standard deviation (MODISµ±σ) and relative absolute error (MODISRAE) for accuracy assessment in spatial averaging and compared with Aerosol Robotic Network (AERONET). The relationship between AODMODIS and AOD from AERONET (AODAERONET) showed R2 value for MODISµ±σ and MODISRAE is 0.906 and 0.932, respectively. AODMODIS over Kuching tends to underestimate AOD during low variations and overestimate AOD when aerosol loading is higher. The retrieval of AODMODIS was used as an input parameter into SBDART for ARF estimation and compared with ARF from AERONET. When using AODMODIS from MODISµ±σ, the ARF at TOA was between -5.95 Wm-2 and 0.89 Wm-2 and at the surface was from -389.7 Wm-2 and -31.4 Wm-2 while for MODISRAE, ARF value at the surface was from -392.3 Wm-2 and -27.3 Wm-2 while at TOA was between -5.89 Wm-2 and 0.98 Wm-2. Average ARF value within the atmosphere for both MODISµ±σ and MODISRAE were 151.6 Wm-2 and 130.4 Wm-2, respectively. There is a poor relationship between the SBDART and AERONET for MODISµ±σ, where R2 is 0.33, while strong relationship is observed for MODISRAE with R2 value at 0.724.
DNA microarray images contain spots that represent the gene expression of normal and cancer samples.
As there are numerous spots on DNA microarray images, image processing can help in enhancing an
image and assisting analysis. The mathematical morphology is proposed to enhance the microarray image
and analyse noise removal on the image. This follows an experiment in which the erosion, dilation,
opening, closing, white top-hat (WTH) and black top-hat (BTH) operations were applied on a DNA
microarray image and its results analysed. Noise was completely removed by the erosion operation and
the images were enhanced.
The watermarking is a method of concealing digital information in multimedia data, namely the host image. Discrete wavelet transform (DWT) when joined with discrete cosine transform (DCT) and SVD deliver powerful digital watermarking image. There are different types of intrusions that either plunder the actual ownership or demolish the appearance. In this paper, the DWT-DCT, DWT-SVD approach has been proposed to ensure security by concealing the watermark inside the actual image and validate the proprietor’s image. Using DWT-DCT and low-bit percentage, the watermark image was inserted and abstracted. The DWT-SVD hybrid produced very good results.
This review is aimed to present an in-depth review of several methodologies on magnetic
water treatment (MWT) that are employed as scale treatment in water pipeline and to
critically discuss each method in order to determine the best outcome of MWT. The
magnetically assisted water in pipeline in various applications are presented, argued and
best variables are listed according to the performance of each MWT. The advantages and
limitations of MWT are discussed and the main outcome from the review summarize the
best method in MWT, especially in effectiveness of treating scale in terms of sustained
environment benefits. Magnetic field application in water treatment has the potential to
improve the water pipeline performance and lifetime. The application is also significant in
controlling the growth of scale in upcoming system. Both of these benefits lead to healthier
water treatment, increasing and maintaining the lifetime and performance of water system.