Displaying publications 141 - 160 of 839 in total

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  1. Eyada, Saadoon Obaid, Celik, Osman N.
    MyJurnal
    Since 1958, most of the world’s countries including Turkey depend on the Empirical
    Pavement Design Method established by AASHO (which is now known as AASHTO).
    The limitation of the data used for preparing AASHTO 1993 and Non-Mechanical Based
    procedure are the main reasons for the needs of new design procedure. The new AASHTO
    design procedure MEPDG has been established in 2002 and adopted by most of the states
    in the USA which is based on Mechanistic-Empirical (M-E) principles. The aim of this
    paper is to prepare a plan for the implementation of MEPDG in TURKEY starting with
    Third Region. The plan consists of two stages. Stage one is concerned with data collection
    and preparing of input files. This stage is subdivided into three tasks namley, Climate File,
    Material File and Traffic File. Stage two is associated with the use of the files prepared
    in Stage one to conduct studies using MEPDG software. These studies are recommended
    by AASHTO to evaluate the applicability of the procedure and the recommended
    enhancements. The studies of this stage are: (a) Sensitivity Analysis of MEPDG to Design
    Inputs; (b) Comparison of specific Third Region Designs with MEPDG designs; and (c)
    Calibration of Performance Models for Third Region in Turkey. The outcomes of this
    paper can be used as guidance for further studies on the implementation of MEPDG
    in other Regions in Turkey. Also the results of these researches can be assembled to
    implement the procedure for whole Turkey.
  2. Chun Lim, Siow, Mohd Syariffuddin, Johari, Chandima, Gomes
    MyJurnal
    Soil plays an important role in ground designing. Engineers normally consider only soil resistivity under normal or steady state condition when designing the grounding system. Under certain circumstances such as lightning, electrical response of the soil will change accordingly and thus, the performance of the grounding system will be affected. The purpose of this study is to investigate the effect of moisture content on the electrical behaviour of sand and clay under high impulse voltage condition. Both soil samples are dried in the oven at 110 ± 5°C to remove the water content until became 0%. The samples are subjected to 30 shots of standard (1.2/50μs) lightning impulse voltage for both positive and negative impulse polarities. This is followed by moistening the samples with 5% amount of water over the volume of the samples. The corresponding V50% for both sand and clay was calculated and the value obtained was converted to standard atmospheric condition. The voltage at breakdown and time to breakdown for each soil sample was analysed a statistical analysis conducted for these two parameters to determine if type of soil and moisture content have an effect on the breakdown voltage. In general, it was found that clay is more efficient in neutralising high impulse voltage than sand likely due to the former’s low resistivity and porosity.
  3. Manzoor, Sama, Yus Aniza Yusof, Ling, Chin Nyuk, Intan Syafinaz Mohamed Amin Tawakkal, Mohammad Fikry, Chang Lee Sin
    MyJurnal
    In this study, papaya (Carica papaya) peel was dried using convection oven and microwave drying methods to investigate the drying kinetics and the drying behavior in the attempt to search for a feasible way to utilize waste peel. Three different drying temperatures (45, 55, and 65 oC) and microwave powers (250, 440, and 600 W) were applied to dry the papaya peel, wherein the drying data were fitted into the following seven drying kinetic models: Lewis, Page, Modified Page, Henderson and Pabis, Logarithmic, Two-Term, and Approximation of Diffusion models. The study outcomes indicated that the Page model emerged as the best fitted model for oven drying of papaya peels with the highest coefficient of determination (R2) value (0.994-0.996) for all the three temperatures. As for microwave drying, the Approximation of Diffusion model exhibited the best fit owing to the highest R2 value (0.996-0.999) for all the three powers. The effective moisture diffusivity values for convection oven and microwave drying methods ranged from 6.65 x 10-08 to 4.35 x 10-07 and from 2.43 x 10-07 to 6.67 x 10-07, respectively. Additionally, the activation energy values were recorded at 61.301 kJ/mol and 46.621 W/g for oven and microwave drying methods, respectively.
  4. Suniza, A.M.S., Zaleha Kassim, Chatterji, Anil
    MyJurnal
    Respiratory metabolism of the larvae of Malaysian horseshoe crab Tachypleus gigas (Müller) was studied under different salinities, pH, and temperature. The trend in oxygen consumption was uniform at all salinities, ranging from 10-40 ppt, indicating insignificant influence on the oxygen consumption by the larvae. Similarly, the correlation coefficient values showed that the relationship between oxygen consumption and salinity was not significant (P > 0.05; r = 0.245). During the first three hours, the oxygen consumption was 8.89, 10.72, 17.4, and 12.06% at 10, 20, 30, and 40 ppt salinities, respectively. Meanwhile, the maximum oxygen consumption was recorded after 12 hrs, i.e. at salinity 20 ppt. A sudden drop in oxygen consumption was recorded during 3-6 hours of the experiment. This was followed by a gradual increase in the consumption of oxygen up to 12 hours of experiment. A similar trend in the oxygen consumption was observed in different pH levels, ranging from 5 to 9. At pH 6 and 9, during the first six hour, a moderate consumption of oxygen was observed. However, at pH 6, 7 and 8, the rates of oxygen consumption were found to be relatively greater after six hours, indicating unfavourable conditions. The data were statistically tested and it was found that a high degree of correlations existed between pH and oxygen consumption (r = 0.97). The analysis of covariance showed a significant relationship between oxygen consumption and pH (P < 0.05). Meanwhile, minimal variation in oxygen consumption was recorded between 30 and 40oC, with a
    gradual decrease in dissolved oxygen concentration up to 12 hours of experimental time. At 50oC,
    almost all dissolved oxygen was consumed by the larvae. The rate of oxygen consumption between
    30 and 40oC was low during the first 9 hours of the experiment but it was significantly increased at later hours. A sudden increase in the oxygen consumption was recorded at 50oC, suggesting that it
    might be the most unfavourable temperature condition. Meanwhile, a significant relationship was
    observed between temperature and oxygen consumption (P < 0.05; r = 0.98).
  5. Tajau, R., Wan Yunus, W.M.Z., Mohd Dahlan, K.Z., Mahmood, M.H., Hashim, K., Ismail, M., et al.
    MyJurnal
    This study demonstrated the utilization of radiation-induced initiator methods for the formation of
    nanoparticles of Acrylated Palm Oil (APO) using aqueous Pluronic F-127 (PF-127) microemulsion
    system. This microemulsion system was subjected to gamma irradiation to form the crosslinked APO
    nanoparticles. Dynamic light scattering (DLS), Fourier Transform Infrared (FTIR) spectroscopy and
    Transmission Electron Microscopy (TEM) were used to characterize the size and the chemical structure
    of the nanoparticles. As a result, the size of the APO nanoparticle was decreased when the irradiation
    dose increased. The decrease in size might be due to the effects of intermolecular crosslinking and
    intramolecular crosslinking reactions of the APO nanoparticles during irradiation process. The size of the
    nanoparticle is in the range of 98 to 200 nanometer (nm) after irradiation using gamma irradiator. This radiation-induced method provides a free initiator
    induced and easy to control process as compared
    to the classical or chemical initiator process. The
    study has shown that radiation-induced initiator
    methods, namely, polymerization and crosslinking
    in the microemulsion, were promising for the
    synthesis of nanoparticles.
  6. Wan, Ngeow Yen, Chin, Khaw Pei, Che Su Mt. Saad
    MyJurnal
    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.
  7. Buari, N.H., Chen, A.H.
    MyJurnal
    A full description of a new reading chart in Malay language, the Buari-Chen Malay Reading Chart (BCMRC) is described. Internal and external comparisons of BCMRC are also reported. BCMRC comprised four reading sets with contextual sentence (CS1 and CS2) and random words (RW1 and RW2) designs. A total of 14 prints, ranging from 1.3LogMAR to 0.0LogMAR in 0.1LogMAR steps (equivalent to 8 M to 0.4 M) were printed in high contrast Arial font. CS1, CS2, RW1 and RW2 were presented in random order to the participants for internal comparison. The reading was evaluated aloud with clear pronunciation (errors were recorded). Maximum reading speed (MRS) was reported in words per minute. The external comparison involved two standard English reading charts [MNread acuity chart (MNread) and Bailey-Lovie words reading chart (Bailey-Lovie)]. The internal and external comparisons were analysed using the intra-class correlation coefficient (ICC) and Cronbach’s alpha (α) respectively. Contextual sentence set (ICC=0.82) and random word set (ICC=0.85) exhibited good reliability in our internal comparison. The external comparison showed acceptable reliability for both MNread (α=0.76) and Bailey-Lovie (α=0.80). BCMRC sets with similar features could be used interchangeably to monitor clinical progress in visual rehabilitation. BCMRC was comparable with MNread and Bailey-Lovie reading charts.
  8. Tin, Ang Gaik, Mohamad Zailani Abu Bakar, Chen, Cheah Mooi
    MyJurnal
    The present investigation deals with the development of ethanol-vapour-sensing materials coated with the semiconducting oxide TiO2. Thick films of anatase TiO2 were deposited using the sol-gel dip-coating technique on alumina substrates by conventional alkoxide sol and modified sol added with Degussa P-25 as the sensing medium. It was shown that crystallised TiO2 anatase was obtained at the annealing temperature of 500oC. The fabricated TiO2 sensors exhibited highest sensitivity at the sensing temperature of 350 ºC. Sensitivity towards the ethanol vapour was further increased with UV light effect. The enhancement of the sensitivity of the modified catalytic pellet can be explained by the crystallite of anatase TiO2 and the effect of the photocatalytic of TiO2. The high sensitivity of the TiO2 film deposited with modified sol revealed that the modified sol could be a new alternative in the development of a TiO2 ethanol sensor.
  9. Ching SM, Chia YC, Cheong AT
    MyJurnal
    This case report highlights delay in the diagnosis of adenoma carcinoma of the lung in a female patient who has never smoked. It took three months to reach the diagnosis of stage IV lung carcinoma despite the presence of symptoms and an abnormal chest radiograph finding from the beginning. The clinical characteristics and predictors of missed opportunities for an early diagnosis of lung cancer are discussed. In this case, patient and doctor factors contributed to the delay in diagnosis. Thus, early suspicions of lung cancer in a woman with the presence of respiratory symptoms despite being a non-smoker are important in primary care setting.
  10. Ee, G.C.L., Cheow, Y.L.
    MyJurnal
    Detail chemical studies on Carcinia maingayi have yielded one xanthone, 1,3,7-trihydroxy-2-(3-methylbut-2-enyl)-xanthone, one benzophenone, isoxanthochymol, one benzoic acid derivative 3,4-dihydroxy-methylbenzoate and two triterpenoids, stigmasterol and sitosterol. Meanwhile, investigations on Carcinia parvifolia have afforded one triterpenoid, a-amyrin and two xanthones, cowanin and rubraxanthone. Their structures were derived based on spectroscopic evidence, mainly ID and 2D NMR spectroscopy. Acetylation reaction was carried out on rubraxanthone to yield triacetate rubraxanthone. It was found that the pure rubraxanthone was strongly active against the larvae of Aedes aegypti with LC50 value of 15.49 {lg/ ml and HL-60 cells line with an IC50 value of 7.5 {lg/ ml.
  11. Siti Fatimah Halim, Soon Kong Yong, Chia Chay Tay
    MyJurnal
    The objective of this study is to elucidate sorption mechanism of ammonia-N by Spent Mushroom Substrate Biochar (SMSB), produced from pyrolysis process of Spent Mushroom Substrate (SMS) at 550°C for two hours. Surface functional group, ash contents, and elemental compositions were analysed using Boehm titration, furnace and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICPOES) respectively. Sorption parameters (i.e., sorbent dosage, input ammonia-N concentration, and contact time) were optimised, and the sorption data were analysed using kinetic models (i.e., pseudo-first-order and pseudo-second-order), and isotherm models (i.e., Langmuir, Freundlich, and Dubinin-Radushkevich (D-R)). The surface of SMSB consists of carboxylic (0.3 mmol/g), phenolic (0.5 mmol/g), and basic functional groups (0.2 mmol/g). Sorption of ammonia-N was best described by the pseudo-second-order kinetic model and the Dubinin-Radushkevich (D-R) isotherm model. The D-R sorption capacity for SMSB was 12.6 mg/g, and correlates well with the amount of acid functional groups (i.e., carboxylic and phenolic groups) in SMSB (i.e., 14.4 mg/g). The low Freundlich constant (n = 0.754), and low D-R mean free energy per mol of the adsorbate (E = 4.4 kJ/mol) indicates a physical sorption process, and ammonia-N binds with acid functional groups through weak forces. The result shows great potential of SMSB for removing ammonia-N in wastewater.
  12. Ching, Chieh Kiu
    MyJurnal
    With the proliferation of Web 2.0 technologies, folksonomy which is also known as social tagging or
    collaborative tagging is widely used by learners to annotate and categorize their learning resources. In
    a folksonomy system, the tags are added by learners to the learning resources, hence the tags are often
    ambiguous, overly personalised and imprecise. In addition, conjugated words, compound words and
    nonsense words may be used in tagging and shared among a group of learners. This has resulted in an
    uncontrolled and chaotic set of tagging terms that cause learning resources searching, reuse and sharing
    to become ineffective. In this paper, we present a content-based approach which automatically generates
    tags from a learning resource using Part-Of-Speech Tagging and K-Means Clustering techniques. The
    generated tags are more precise and unambiguous which can improve learning resources searching,
    reuse and sharing among learners.
  13. Ahmad, R., Virgiyanti, W., Mahmod, M., Habbal, A., Chit, S.C.
    MyJurnal
    Crowdsourcing introduces new perspectives in innovation, allowing for new products and services to shift away from the traditional manufacture-centric model to a more user-centric one. In order for businesses to reap the benefits of open innovation, it is necessary to understand the factors that motivate ideators to contribute valuable ideas. Equally, there is an urgency to identify the challenges faced by ideators in crowdsourcing for open innovation to retain the participants of crowdsourcing communities. This paper presents a structured review to address the aforementioned issues. Our findings reveal that the intrinsic factors that drive participation in open innovation are related to the learning experience that results from sharing ideas. Extrinsic factors like social motivation are frequently mentioned in different studies. This study also highlights the need for organisations to develop strategies for interacting with their contributors in order to sustain their participation and idea contribution. In conclusion, this paper can serve as a guideline for practitioners to improve crowdsourcing platforms with the inclusion of important motivational features. It can also serve as reference for organisations for formulating policies to regulate idea contribution.
  14. Ho, C. L. I., Choo, B. Q.
    MyJurnal
    In this paper, stormwater runoff from a residential catchment located in Miri, Sarawak, was characterized to determine the pollutant concentrations and loading. The observed average event mean concentrations were 116 mg/L for TSS, 115 mg/L for COD, 1.5 mg/L for NH3-N, and 0.23 mg/L for Pb. Based on Interim National Water Quality Standards (INWQS) for Malaysia, the average event mean concentration, EMC value for TSS exceeded class II (50 mg/L), exceeded class V (>100 mg/L) for COD, and exceeded class III (0.9 mg/L) for NH3-N. All four water quality parameters exhibited first flush characteristic but to varying magnitude which was influenced by the storm characteristics.
  15. Huat, Bujang B.K, Faisal AIi, Choong, Foong Heng
    MyJurnal
    Residual soils occur in most countries of the world but the greater areas and depths are normally found in tropical humid areas. In these places, the soil forming processes are still very active and the weathering is much faster than the erosive factor. Most residual exhibit high soil suctions for most of the year. The absence of positive pore water pressure except immediately after rain, renders conventional soil mechanics for saturated soil irrelevant. In particular, the effective stress theories of saturated soil are not applicable at the practical leve l. Ignorance or lack of understanding of the geotechnical behavior of soil in the partially or unsaturated state has caused a lot of damages to infrastructures, buildings and other structures. For instances, the collapsibility and volume change of partially saturated soils in connection with the drying or wetting causes a lot of damage to foundation, roads and other structures. As such, the development of extended soil mechanics, which embraces the soil in the unsaturated state or subjected to soil suction, is essential. This paper examines the collapsibility and volume change behavior specifically of an unsaturated residual soil under various levels of applied matric suction (u -u ), and net mean stress (a-u) in a predetermined stress path. The volume change of ;he"' soil is found to be sensitive to both the applied matric suction and net mean stress. The soil is found to exhibit a collapsibility behavior upon a reduction in applied matric suction to 25 kPa at constant net mean stress.
  16. Azhari Muhammad Syam, Robiah Yunus, Tinia Idaty Mohd. Ghazi, Choong, Thomas Shean Yaw
    MyJurnal
    Research on the use of Jatropha curcas triglycerides as biodiesel feedstock has received worldwide attention due to its inherent characteristics. Unlike palm oil, J. curcas oil is not edible, and thus, it will not disturb the food supply. However, to the researchers' experiences with the synthesis of J. curcas, oil-based biodiesel has shown that the fuel characteristics depend largely on the type of alcohol used as the excess reactants. Transesterification reaction is chosen for this process with sodium methoxide as the catalyst. Comparison studies on the yield of esters using methanol and ethanol, as well as the impacts on the reaction rate are discussed. The effects of reaction time and molar ratio on the reaction conversion are also examined. The determination of reaction yield is based on the conversion of triglycerides into alkyl esters as the main product. The findings are described as follows: the highest percentage yield of product is attained at 96% for methanol as an excess reactant, and this is 90% when ethanol is used. The optimum conditions of parameters are achieved at 6:1 molar ratio of alcohol to triglycerides, 50 min of reaction time and reaction temperature of 65°C for methanol and 75°C for ethanol. The biodiesel properties of both ester fuels were determined according to the existing standards for biodiesel and compared to the characteristics of diesel fuel.
  17. Sitti Rachmawati Yahya, Khairuddin Omar, Siti Norul Huda Sheikh Abdullah, Choong-Yeun Liong
    MyJurnal
    In this paper, an image binarization method for separating text from the background of degraded textual images is proposed. This proposed methods are based on combination of Window Tracking Method (WTM) and Dynamic Image Histogram (DIH). The WTM and DIH methods work on an image that has been pre-processed. The WTM method searches for the largest pixel value in a 3 × 3 window up to a maximum of five tracking steps, while the method searches for a definite frequency between the two highest values in the image histogram. We test proposed method on DIBCO dataset and self-collection faded manuscripts. The experimental results show that our proposed method outperforms state of the art methods.
  18. Sebastian, Patrick, Yap, Vooi Voon, Comley, Richard
    MyJurnal
    This paper presents a tracking method based on parameters between colour blobs. The colour blobs
    are obtained from segmenting the overall target into multiple colour regions. The colour regions are
    segmented using EM method that determines the normal colour distributions from the overall colour
    pixel distribution. After segmenting into different regions on the different colour layers, parameters
    can be generated between colour regions of interest. In this instance, the colour regions of interest are
    the top and bottom colour regions. The parameters that are generated from these colour regions are
    the vector magnitude, vector angle and the value difference between colour regions. These parameters
    are used as a means for tracking targets of interest. These parameters are used for tracking the target
    of interest across an array of cameras which in this instance are three cameras. Three cameras have
    been set up with different background and foreground conditions. The summarised results of tracking
    targets across three cameras have shown that the consistency of colour regions across different cameras
    and different background settings provided sufficient parameters for targets to be tracked consistently.
    Example of tracking performance across three cameras were 0.88, 0.67 and 0.55. The remaining tracking
    performances across three cameras are shown in Table 2. The tracking performance indicate that the
    parameters between colour regions were able to be used for tracking a target across different cameras
    with different background scenarios. Based on results obtained, parameters between segmented colour
    regions have indicated robustness in tracking target of interest across three cameras.
  19. Az Azrinudin Alidin, Crestani, Fabio
    MyJurnal
    Mobile users have the capability of accessing information anywhere at any time with the introduction of mobile browsers and mobile web search. However, the current mobile browsers are implemented without considering the characteristics of mobile searches. As a result, mobile users need to devote time and effort in order to retrieve relevant information from the web in mobile devices. On the other hand, mobile users often request information related to their surroundings, which is also known as context. This recognizes the importance of including context in information retrieval. Besides, the availability of the embedded sensors in mobile devices has supported the recognition of context. In this study, the context acquisition and utilization for mobile information retrieval are proposed. The “just-in-time” approach is exploited in which the information that is relevant to a user is retrieved without the user requesting it. This will reduce the mobile user’s effort, time and interaction when retrieving information in mobile devices. In this paper, the context dimensions and context model are presented. Simple experiments are shown where user context is predicted using the context model.
  20. Bachtiar, D., Sapuan, S.M., Zainudin, E.S., Khalina, A., Dahlan, K.Z.H.M.
    MyJurnal
    Thermal characterization of sugar palm fibre (SPF), reinforced high impact polystyrene (HIPS)
    composites, was studied by means of thermogravimetric analysis. The effects of alkaline treatment and compatibilizing agent on the thermal stability of the composites were evaluated. Alkaline treatment was carried out by soaking the fibres in 4 and 6% of NaOH solution, while treatment with compatibilizing agent was employed by adding 2 and 3% maleic anhydride-graft-polystyrene (MA-g-PS) to the composites. Both the treatments were aimed to improve the mechanical performance of the composites. From the study, the thermal stability of the treated composites was found to be higher than that of untreated composites. It is shown that the incorporation of sugar palm fibre influences the degree of thermal stability of the composites. The treatments on composites also contributed to shifting the peak temperature of degradation of the composites. In other words, there are strong chemical reactions between the components of the treated composites. The thermal stability of the composites, with alkaline treatment and compatibilizing agent, was found to be better as compared to those of the untreated composites.
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