Surface sediments were collected from the north western intertidal area (14 sites), drainage (3 sites), and rivers (3 sites) of Peninsular Malaysia in April 2005. The samples were analyzed for their concentrations of Cd, Ni, and Zn. The ranges for the total concentrations (µg/g dry weight) of Cd, Ni, and Zn were found to be 0.79-2.48, 6.46-73.92, and 33.6-484.14, respectively. Factory drainage site at Juru exceeded the established sediment quality values (Effect Range Median-ERM) for Zn and Ni, while the concentrations of Zn were also found to have exceeded the ERM at drainages at Kuala Kurau Town and Sg. Juru sites. The geochemical study, based on the sequential extraction technique on the sediments, revealed that the metal percentages of non-resistant fractions of the drainage at Kuala Kurau Town (drainage), Sg. Juru (river), Kuala Juru (intertidal), and factory drainage site at Juru were higher than the resistant fractions of the metals. These indicated that the sites (intertidal, river, and drainages) received anthropogenic inputs of these metals. Therefore, the point source of anthropogenic input in these sites should be given attention in future in order to mitigate the environmental problem on the living resources in the north western of Peninsular Malaysia. The present monitoring data are useful for future establishment of sediment quality guideline for Malaysian aquatic environment.
Composite structures and materials are used in aerospace, marine and automotive applications due
to their light weight characteristics. By using rice husk ash (RHA) as natural binder to replace epoxy
resin, it improves the characteristic of the composite laminated structure. Rice husk has become an
important ingredient in silica, silicon carbide, and silicon nitride because of its high a silicon content.
This paper evaluates the performance of laminated composite plate in a drop-weight impact testing. Two
plates are attached to the test rig in the particular desired impact orientation. The main advantages of
this process are the plates provide more realistic drop-weight impact and data. Data from the impact test
was collected and analysed to evaluate the material properties of epoxy resin and RHA. Results show
RHA’s energy absorption is better and it has more deformation to prevent structure failures compared
with epoxy resin. This paper aims to evaluate the application of RHA as a geopolymer binder and flax
fibre as an alternative material to glass fibre in the composites industry.
The water flow-like algorithm (WFA) is a relatively new metaheuristic algorithm, which has shown good solution for the Travelling Salesman Problem (TSP) and is comparable to state of the art results. The basic WFA for TSP uses a 2-opt searching method to decide a water flow splitting decision. Previous algorithms, such as the Ant Colony System for the TSP, has shown that using k-opt (k>2) improves the solution, but increases its complexity exponentially. Therefore, this paper aims to present the performance of the WFA-TSP using 3-opt and 4-opt, respectively, compare them with the basic WFA-TSP using 2-opt and the state of the art algorithms. The algorithms are evaluated using 16 benchmarks TSP datasets. The experimental results show that the proposed WFA-TSP-4opt outperforms in solution quality compare with others, due to its capacity of more exploration and less convergence.
The assumption when constructing a control chart is that the process parameters, i.e. mean and standard deviation, are known. Nevertheless, this assumption is not realistic in practical situations. In most of the application of a control chart, the mean and standard deviation are unknown and are estimated from an in-control Phase-I samples. When the process parameters are estimated, the control chart performs differently compared with the corresponding chart with known process parameters because of the variability of estimators. The usual practice to evaluate the performance of a control chart is to use the average run length (ARL). The ARL is the average number of samples plotted on a control chart before an out-of-control signal is detected. In addition, the expected ARL (EARL) is used as a performance measure for the random process mean shift. In this article, the performance of the side sensitive group runs (SSGR) chart with known and estimated process parameters are studied and examined in terms of ARL and EARL.
With a view to understanding the effect of rare earth element (Ce, Pr, Nd, Sm and Gd) substitution for the La site in LaMnO3 (LMO), the samples were prepared via solid-state reaction. Structure investigation by X-ray diffraction (XRD) showed that structure transformation from trigonal (LMO) to orthorhombic (PMO, NMO, SMO and GMO) occurred when smaller trivalent rare earth element was replaced. The MnO6 octahedra were tilted and elongated or compressed, corresponding to the ionic radii of the rare earth inserted. Meanwhile, microstructure study using scanning electron microscopy (SEM) illustrated that La substitution by another rare earth element caused a reduction in grain size. This might due to the changes in enthalpy of fusion by other rare earth ions, where higher enthalpy of fusion favours formation of smaller grain size. However, CeMnO3 did not form under this preparation condition. The magnetic properties studied from the hysteresis plot taken at room temperature indicated that the substitution of La with other magnetic trivalent rare earth ions strongly weakened the magnetic strength of the system.
Dye-sensitized solar cell (DSSC) is the third generation of thin film solar cell. In this work, carrot fruit dye was prepared and used in DSSC as a sensitizer. TiO2–ZrO2 fine binary oxide was mechanochemically prepared and made paste. TiO2–ZrO2 paste (colloidal) was deposited onto FTO/glass in two ways, i.e. as single and double coatings by rolling method. It was immersed in the carrot solution to get dyed cell. The dyed TiO2-ZrO2-FTO/glass cell was offset with the FTO/glass cell coated with adhesive carbon paste. Photovoltaic properties of prepared TiO2–ZrO2 DSSC cell were measured. Results showed that the efficiency of double coating cell was greater than that of the single coating cell. According to the fill factor from the experiments, both the DSSC cells were acceptable for industrial requirement. Hence, it can be concluded that the results obtained were acceptable in the use of cost-effective and eco-favourable dye-sensitized solar cell.
Solid waste management in developing countries including Malaysia is dominated by waste dumpsites which have a high possibility of transporting organic and inorganic pollutants to the underlying groundwater and surface water within the surrounding area. The objective of this study is to characterise the landfill leachates and its surrounding groundwater and river water quality and metals concentrations, namely arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) from Beris Lalang, Kelantan. Nine sampling points were collected within the dumpsite for analysis of in-situ: dissolved oxygen (DO), pH, total dissolved solids (TDS), conductivity, turbidity and ex-situ; Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Suspended Solids (SS) and the results were compared with permissible limits. As and Pb in groundwater samples were collected from the surface of two dug grounds within the vicinity of the dumpsites exceeded the standard of Ministry of Health. Cr, Cu and Pb in leachates exceeded Environmental Quality Act (EQA, 1974)’s standard, whereas Ni, Pb and Zn in surface water of Gali River exceeded the limit of class III National Water Quality Standard (NWQS). Exceeding metals concentration in leachates and its surrounding groundwater and river water relative to their respective standards points out toward potential leachate migration to the waterbodies within the surrounding vicinity of Beris Lalang dumpsite. This study provides the initial baseline data and preliminary monitoring assessments as a first step towards improving water security and waste management in Kelantan.
Algae biodiesel is undeniably very promising as an energy substitute for fossil fuel. It mass cultivation though requires huge capital investment. The aim of this study was to find a simple, inexpensive and tolerable media for algae growth. The optimal growth conditions for algae growth were studied. Botryococcus sp. was isolated from Sembrong Dam in Johor, Malaysia. In this study, two media were used, namely bold’s basal medium (BBM) and synthetic media from nitrogen and phosphorus compound. The synthetic media consisted of ammonium chloride and monopotassium phosphate that were blended together and modified into desired ratios. The N: P ratio of 1.5:1 yielded the highest chlorophyll-a concentration and the optimal growth conditions of algae for both media were at 6000 Lux, pH 7 and 30 rpm. The BMM had the highest algae growth, 3.25 x 107cell/ml while the synthetic media yielded a maximum cell concentration of up to 1.025 x 107 cell/ml which is 68.5% lower compared with BBM. The findings of this study point to the importance of large scale production of algae useful for industrial production of biodiesel.
Compartmented Fluidized Bed Gasifier (CFBG), consisting of two compartments - the combustorand gasifier, uses air blown instead of pure oxygen for syngas production in bubbling fluidization mode, eliminating the need of air separation unit, and reducing the capital cost, thus distinguishes it from other traditional ones. Fluidization quality is a determining factor in the CFBG to guarantee its well-lifted behaviour. Previous study, without solid circulation at ambient conditions, brought to the fore the necessity of considering the effect of the minimum allowable effective diameter. The study was then performed in the CFBG cold physical model of 0.66m overall diameter (effective diameter for combustor and gasifier is 0.413m and 0.257m) to investigate the fluidization quality and compare it with the results obtained from the previous cold model of about 1.36 times smaller, but with the same compartmented ratio of 65:35. Different inert particles (river sand, quartz sand and alumina) were used, over a range of aspect ratios, for the aforementioned objective. The results showed that the fluidization quality in the gasifier has not been achieved and the degradation of fluidization quality in the combustor is still observed, notwithstanding the fact that the condition of the minimum allowable effective diameter has been met. The reduction of distributor free area, to increase the distributor pressure drop, showed a marginal effect on the quality. The effect of the minimum allowable effective diameter on fluidization quality in CFBG as well as the interplay of geometric and operational parameters require further studies be carried out. The fluidization quality of the binary mixture is also currently under investigation.
Reclaimed rubber from rejected natural rubber (NR) latex gloves (r-NRG) was evaluated as partial
replacement for Standard Malaysian Rubber (SMR) 20 in producing microcellular rubber. In the study, the amount of reclaimed rubber varied from 20 pphr to 95 pphr for the purpose of cost reduction, environmental interest and as processing aids in reducing internal porosity, swells and to minimize shrinkage and air-trapped problems in producing microcellular rubber. A typical formulation in making microcellular rubber slab was developed and two-roll mill was used for compounding. The cure characteristics and mechanical properties, such as density, hardness, tensile strength, and elongation at break, were evaluated. Scorch time and cure rate index performed marginal decreased with increasing of r-NRG content. 95 pphr r-NRG blends showed a consequential drop in hardness. Both tensile properties and elongation at break decreased as the r-NRG content was increased.
A study was conducted to identify the responses of Aedes albopictus to different diet regime towards the development of juvenile and adult mosquitoes. Fish pellet was selected as standard diet in order to study the effect of diet regime on the development of Ae. Albopictus. Four different diet regimes (1.0 mg, 0.6 mg, 1.0 mg an1.6 mg) were tested on 50 eggs of Ae. albopictus under laboratory conditions. Juvenile development until adult emergence was observed and recorded. Results indicated that the time taken to mature the mosquitoes was significantly affected by the diet regime. Furthermore, juvenile body size and adult wing size of Ae. albopictus were found to be greatly affected by diet regime exposed during juvenile stages. In summary, an increase of diet regime resulted in the decrease of developmental time and an increase in juvenile body size and adult wing size.
Oxidation of low-density lipoprotein (LDL) and activation of the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) are critical for the inflammatory response for endothelial dysfunction. The objective of this study is to investigate the effects of various doses of HDL on: (a) LDL susceptibility to oxidation; (b) expression of eNOS; and (c) expression of NF-κB p50 and p65. Different concentrations of HDL were incubated in LDL. The reaction rates of LDL susceptibility to oxidation were obtained by kinetic modeling analysis. For determination of eNOS, NF-κB p50 and p65 expression, different HDL concentrations were incubated in lipo polysacharides (LPS)-stimulated human umbilical vein endothelial cell line for 16 hours. Protein was extracted and analysed by western blot and nuclear transcription factor, for example, Co-incubation of LDL with increasing HDL concentrations showed longer lag time and lower reaction rate in a dose-dependent manner compared to controls (p
The transformation method (TM) of fuzzy arithmetic is aimed at simulation and analysis of a system. The aim of this paper is to use fuzzy arithmetic based on the TM on a state space of a steam turbine system. The model is then used to identify the degree of influence of each parameter on the system. Simulation and analysis of the system are presented in this paper.
This animal modelling study aimed to investigate the effects of LDR exposure on cellular ROS production,
oxidative DNA damage, and alteration of cellular ultrastructure and apoptosis-related protein expressions.
Ten male ICR mice were randomly divided into two groups consisting of control (Cx) and radiation
(Rx) groups. On day 29 of post-acclimatisation, mice underwent total body irradiation with 100 µGy
X-ray. Liver and lung tissues were assessed for the levels of cellular ROS production and Apurinic/
Apyrimidinic sites generation. Ultrastructural alteration was detected using TEM, alteration of p53,
Bax, and Bcl-2 expressions was determined by western blotting. Results showed that exposure to LDR
significantly increased the levels of cellular ROS and AP sites in mice. Ultrastructure of the nucleus in
Rx showed nuclear blebbing and structural changes in morphology that indicate cell death. Meanwhile,
p53, Bax, and Bcl-2 proteins increased in expressions and altered the balance of Bax/Bcl-2 ratio. These
findings may postulate that LDR exposure may enhance oxidative DNA damage and alter expression
of apoptosis-related proteins.
The application of computer and machines for agricultural production has been one of the outstanding
developments in Malaysian agriculture, especially in overcoming labour shortages in Oil Palm plantations. The on-line automated weedicide sprayer system was developed at Universiti Putra
Malaysia to locate the existence and intensity of weeds in real-time environment and to spray the
weedicides automatically and precisely. During the start of the spraying operation, the web camera
will initially capture the image of weeds. The computer programme will compute the red, green, blue (RGB) values in the form of computer pixel. These values will be used as reference RGB values to be compared with the RGB values of the weeds captured real-time during the spraying operation. The sprayer nozzle will be turned ‘on’ or ‘off’, depending on the percentage or intensity of the green colour pixel value of weeds. The sprayer valve will open the nozzle/s when the camera detected the presence of weeds. The purpose is to reduce wastage, reduce labour, reduce cost, and control environment hazard.
This paper describes the design and development of harvesting system for the gantry system to harvest eggplants. For this purpose, the harvesting robot was successfully designed and fabricated for the gantry system to harvest eggplants. The operation of the harvester was controlled by Programmable Logic Controller (PLC). Basically, the limit switches, DC motor, and relay are connected to the PLC. Meanwhile, a PLC ladder diagram was designed and developed to control the operation of the eggplant harvester. A visual basic programme was developed to interface the harvester with a greenhouse gantry control system. A videogrammetry method was employed to calculate the distance between the stems of eggplants and the cutter of robot end effector. The end effector used electric as its power source and it was controlled via Programmable Logic Controller (PLC). Visual Basic Programme was developed to interface the harvester with the gantry control system. The accuracy of the videogrammetry was tested to be 67.2% for X-axis, 88.2% for Y-axis and 84.7% for Z-axis. Meanwhile, the speed of the end effector for harvester is 2.4 km/h and it could lift up to 55 cm. In order to determine detachment force of eggplant, 16 samples of mature eggplants were tested in a greenhouse, and as a result, more than 22.76 N force was needed to detach a mature eggplant inside the gantry system.
Vapour pressure deficit (VPD) analysis introduces an approach to develop a better basis for the control of the environment of lowland greenhouses in Malaysia. The study of vapour pressure deficit (VPD) is to show air moisture conditions for plant production while taking into account different temperature levels. The purpose of this project is to develop a real-time automatic temperature and relative humidity control system in the lowland tropical greenhouse using a PIC16f876A microcontroller. The controller will then be used to monitor the temperature, relative humidity and VPD in the planting of Chili Kulai (Titisan 15). The fertigation system was introduced to the greenhouse to fertilize and irrigate the plant as well as to provide moisture to the environment. A swamp cooler was used to bring down the temperature and increase moisture content in the greenhouse. Ventilators were installed to remove the heat in the greenhouse. The study was carried out in an experimental greenhouse located at the Institute of Advanced Technology, Universiti Putra Malaysia (UPM).
In this paper, we proposed a new readout circuit in order to improve measurement output while reading the grouped resistive value in matrix array form. The purpose of having this circuit is to overcome the main problem in applying piezoresistive pressure sensor array for foot plantar application. This new approach is called Nodal Array Approach (NAA), a modified version of Wheatstone Bridge Circuit based on nodal analysis technique using Kirchcoff Current Law. The NAA calculates the sensors’ resistance values by solving simultaneous equations from reading voltages of the proposed readout circuit. Therefore, it is found that the readout circuit connection is of low complexity as it only uses resistive element as the major component of reading technique with only four iterations involved for each voltage nodes. Through simulation results, it shows that NAA is able to achieve high accuracy in obtaining a sensor’s resistance value by adhering to several limitations in order to avoid miscalculation (< 5% average calculation error).
This study was conducted to investigate mitochondrial, nuclear chromatin and cytoskeletal organisation of vitrified embryos based on timing of the first zygotic cleavage. Embryos were retrieved from superovulated ICR mice, 28 hours after hCG injection. Two-cell stage embryos were categorised as earlycleaving (EC), while zygotes with 2-pronuclei as late-cleaving (LC) embryos. Embryos were cultured overnight in M16 medium supplemented with 3% bovine serum albumin (BSA) in carbon dioxide incubator. After 20 hours, the embryos were vitrified for one hour and warmed to room temperature. They were then fixed and immunostained to visualise distribution and intensity of mitochondria, nuclear chromatin and cytoskeleton. Finally, the embryos were mounted on glass slides and examined under a Confocal Laser Scanning Microscope (CLSM). Fluorescence intensities were analysed using LAS-AF-Lite Software. Results showed that EC embryos had significantly higher mitochondria (39.22 ± 12.50 versus 35.42 ± 14.61 pixel, p
Minimally invasive surgery results in faster recovery. The objective of this study is to identify criteria for the feasibility of 24-hour discharge post laparoscopic ovarian cystectomy. This is a prospective cross-sectional study that was carried out at the Obstetrics and Gynaecology Department in Putrajaya Hospital between 1 January and 31 December, 2016. The inclusion criteria were: age between 15 and 45, no comorbidities, no family history of malignancy, BMI of less than 30, mass size less than 18 weeks, single uninoculated simple cyst and no ascites. The exclusion criteria were post-menopause women, known medical illness, family history of malignancy, mass size more than 18 weeks, multiloculated or bilateral ovarian cyst, presence of solid area within the cyst and ascites. The sample size was calculated to be 14. A total of 16 participants were identified. Results showed that using the Visual Analogue Score (VAS), the mean pain score post operatively in the first six hours, 24 hours, 48 hours, two weeks and three months were 3.67, 2.57, 0.5, 0 and 0, respectively. Two of the subjects experienced post-operative nausea and vomiting, one had urinary tract infection and one had minor bleeding from the surgical site. All the participants were discharged within 24 hours post-operatively. There was no readmission. In conclusion, 24-hour discharge post laparoscopic cystectomy is safe and feasible. Factors determining the success must be adhered to closely to ensure a good and satisfactory outcome. This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.