Displaying publications 141 - 160 of 839 in total

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  1. Siregar, Januar Parlaungan, Mohd. Sapuan Salit, Mohd. Zaki Ab. Rahman, Khairul Zaman Hj. Mohd. Dahlan
    MyJurnal
    This paper studied the thermal behaviour of pineapple leaf fibre (PALF) reinforced high impact polystyrene (HIPS) composite. Thermogravimetric analysis (TGA) and differential scanning calorimetric (DSC) analysis were used to measure the thermal characteristic of HIPS/PALF composites. In particular, the TGA analysis was utilized to measure the degradation and decomposition of materials in neat polystyrene, pineapple fibre, and the composites. The measurements were carried out in the temperature of 25°C – 800°C, at a heating rate of 20°C min-1 and the nitrogen gas flow was 50 mL min-1. The temperature of the DSC analysis was programmed to be between 25°C – 300°C. The results from TGA analysis show that the addition of pineapple fibre has improved the thermal stability of the composites as compared to neat HIPS. In addition, the effects of compatibilising agent and surface modification of PALF with alkali treated were also determined and compared.
  2. Siregar, J.P., Sapuan, S.M., Rahman, M.Z.A., Zaman, H.M.D.K.
    MyJurnal
    A study on the effects of alkali treatment and compatibilising agent on the tensile properties of pineappleleaf fibre (PALF) reinforced high impact polystyrene (HIPS) composite is presented in this paper. Thetensile properties of natural fibre reinforced polymer composites are mainly influenced by the interfacialadhesion between the matrix and the fibres. In this study, several chemical modifications were employedto improve the interfacial matrix-fibre bonding and this resulted in the enhancement of tensile propertiesof the composites. In this study, the surface modification of pineapple fibre with alkali treatments andcompatibilizer were used to improve the adhesion between hydrophilic pineapple fibre and hydrophobicpolymer matrix. There are two concentrations of NaOH treatments and compatibilizer used in this study,namely, 2 and 4 wt. %. The results show that the alkali treated fibre and the addition of compatibilisingagent in PALF/HIPS composites have improved the tensile strength and tensile modulus of the composites.
  3. Sirageldin, Abubakr, Baharum Baharudin, Low, Tang Jung
    MyJurnal
    Developing a trust management scheme in mobile computing environment is increasingly important,
    and the effective trust management model is a challenging task. Business, education, military, and
    entertainment have motivated the growth of ubiquitous and pervasive computing environments, which are always available due to the widespread of portable and embedded devices. Wireless and mobile computing are good example of ubiquitous and pervasive computing environments. Due to the uncertainty and mobility in such environments, the issue of trust has been regarded as an important security problem. Malicious nodes are a major threat to these networks; the trust system can monitor the behaviour of nodes and accordingly rewards well-behaved nodes and punishes misbehaving ones. At present, there are a lot of endeavours on the trust model of the pervasive computing environment. In this paper, a trust management framework for mobile computing is presented. The hybrid framework is based on a fusion of the support vector machine (SVM) and fuzzy logic system. From the results, it can be stated that the framework is effective, dynamic, lightweight, and applicable.
  4. Sinin Hamdan, Iran Amri Musoddiq, Ahmad Fauzi Musib, Marini Sawawi
    MyJurnal
    The tone of peking 1, 2, 3, 5, 6, 1’ was investigated using time-frequency analysis (TFA). The frequencies were measured using PicoScope oscilloscope, Melda analyzer in Cubase version 9 and Adobe version 3. Three different approaches for time-frequency analysis were used: Fourier spectra (using PicoScope), spectromorphology (using Melda analyzer) and spectrograms (using Adobe). Fourier spectra only identify intensity-frequency within entire signals, while spectromorphology identify the changes of intensity-frequency spectrum at fixed time and Adobe spectrograms identify the frequency with time. PicoScope reading produces the spectra of the fundamental and overtone frequencies in the entire sound. These overtones are non-harmonic since they are non-integral multiples of the fundamental. The fundamental frequencies of peking 1, 2, 3, 5, 6 were 1066Hz (C6), 1178Hz (D6), 1342Hz (E6), 1599Hz (G6) and 1793Hz (A6) respectively while peking 1’was 2123Hz (C7) i.e. one octave higher than peking 1. Melda analyzer reading proved that all peking sustained the initial fundamental frequency and overtone at t=0 until 2s. TFA from Adobe reading provides a description of the sound in the time-frequency plane. From TFA, peking 1, 2 and 6 exhibited a much gentler attack and more rapid decay than peking 3, 5 and 1’.
  5. Sinha, P.C., Jena, G.K., Rao, A.D., Mohd Lokman Husain, Jain, Indu
    MyJurnal
    A depth-averaged numerical model was developed to study tidal circulation and suspended sediment transport in the gulf of Khambhat along the west coast of India. The spatial resolution of the model is 750m x 750m. A 2-D fine resolution (150 m x 150 m) model for the lower part of the Narmada estuary is coupled with the coarser gulf model to simulate the flow features in the lower estuary. The model dynamics and basic formulation remain the same for both the gulf model and the estuary model. The models are barotropic, based on the shallow water equations and neglect horizontal diffusion and wind stress terms in the momentum equations. The models are fully non-linear and use a semi-explicit finite difference scheme to solve mass, momentum, and advection- diffusion equation for suspended sediments in a horizontal plane. The erosion and deposition have been computed by an empirically developed source and sink term in the suspended sediment equation. The tide in the gulf is mainly represented in the model by the semi-diurnal M2 constituent. Meanwhile, fresh water discharge from the rivers joining the gulf had also been considered. Numerical experiments were carried out to study the circulation and suspended sediment concentrations in the gulf and estuarine region.
  6. Sim, F.S., Mohd Irwan Lu, N.A.L., Lee, Z.E.T., Mohamed, M.
    MyJurnal
    In this study, agriculture biomass was used to remove dissolved organic matter from peat swamp runoff. The functional groups and morphological properties of 6 tropical agriculture biomasses (coconut husk, rice husk, empty fruit bunch, sago hampas, saw dust and banana trunk) in their raw and citric acid–treated states were examined. The Fourier transform infrared (FTIR) spectra showed that various biomasses were typically characterised with lignocellulosic compounds. The spectra analysis further demonstrated that citric acid treatment resulted in the dissolution of lignin and hemicelluloses to various extents where carboxyl groups were also introduced. These changes hypothetically suggest improved adsorption ability. Treatment of peat swamp runoff with various untreated biomasses showed no adsorption. With the modified biomass, adsorption was evidenced, with rice husk illustrating the highest removal efficiency of 60% to 65%.The biosorbent can be used in the water treatment process especially for treating water with a high dissolved organic matter content. The spent sorbent can be subsequently applied as a soil conditioner as the dissolved organic fraction, commonly known as humic matter, possesses important agricultural value.
  7. Sim, C.K., Abdullah, K., Mat Jafri, M.Z., Lim, H.S.
    MyJurnal
    Microwave Remote sensing data have been widely used in land cover and land use classification. The objective of this research paper is to investigate the feasibility of the multi-polarized ALOS-PALSAR data for land cover mapping. This paper presents the methodology and preliminary result including data acquisitions, data processing and data analysis. Standard supervised classification techniques such as the maximum likelihood, minimum distance-to-mean, and parallelepiped were applied to the ALOS-PALSAR images in the land cover mapping analysis. The PALSAR data training areas were chosen based on the information obtained from
    optical satellite imagery. The best supervise classifier was selected based on the highest overall accuracy and
    kappa coefficient. This study indicated that the land cover of Butterworth, Malaysia can be mapped accurately
    using ALOS PALSAR data.
  8. Siew-Yi Lee, Siti Aqlima Ahmad, Siti Roslina Mustapha, Janna Ong-Abdullah
    MyJurnal
    Despite wide applications in industries, phenol pollution leads to many health effects, and one of the technologies used to clean up phenol pollution is phytoremediation. The aim of this research was to assess the remediation ability of Ipomoea aquatica Forssk., which is easy to handle and and has a fast growth rate. Plantlet was grown in water spiked with 0.05, 0.10, 0.20, 0.30 and 0.40 g/L phenol, followed by daily observation of the plantlets morphology and tracking of phenol concentration in the water and plantlet extracts via 4-aminoantipyrine (4-AAP) assay. Plantlet’s roots in 0.10 g/L phenol (57.42 ± 1.41 mm) were significantly longer (p < 0.05) than those of the control plantlets (43.57 ± 3.87 mm) in contrast to other phenol concentrations which had stunted roots growth. I. aquatica Forssk. was able to survive with 0.30 g/L phenol despite exhibiting yellowing of leaves and increased sensitivity to scarring on the stems. The plantlets were able to completely remove the phenol from the water spiked with phenol at 0.05 g/L after 12 days of growth. However, the highest average rate of phenol removal was 0.021 g/L/day from water spiked with 0.30 g/L phenol. Phenol analysis on the plantlets’ extracts revealed that I. aquatica Forssk. had degraded the absorbed phenol. This observation is of significant interest as it highlights the
    potential of I. aquatica Forssk. for use as a phytoremediator to clean up phenol contaminated water.
  9. Siew, Ching Ngai, Ramasamy, Rajesh, Syahril Abdullah
    MyJurnal
    Many diseases are potential targets for gene therapy using either non-viral or viral vectors. Unlike nonviralmethods, viral vectors, such as lentiviruses, have the ability to integrate into the host chromosome,which can lead to long-term transgene expression. Lentiviruses have advantages over other types ofviruses due to their capacity to transduce non-dividing cells. An optimized generation of lentivirusescarrying green fluorescent protein (GFP) reporter gene driven by either UbC (LV/UbC/GFP) orCMV (LV/CMV/GFP) promoter is described in this paper. The lentiviruses were produced by cotransfectinglentiviral expression constructs and packaging mix into 293FT lentivirus producer cell lines.Lipofectamine was highly efficient in transfecting the cells compared to Transfast and Polyethyleneimine(PEI). Following cell transfection, syncytia were clearly visible at day 2. Lentiviruses were harvestedat days 1, 2 and 3 post-transfection. The highest transduction efficiency was read from LV/CMV/GFPharvested at day 2 post-transfection and LV/UbC/GFP harvested at day 3 post-transfection. Finally,the GFP expression in COS-7 cells was determined at day 2 and day 14 post-transduction for transientand stable GFP expression. It was found that the GFP expression declined overtime. However, thetransduction efficiency and duration of the transgene expression in COS-7 cells transduced with LV/CMV/GFP were higher compared to LV/UbC/GFP. In conclusion, we have successfully produced lentivirusescarrying GFP with different promoters and shown that the viruses were able to infect COS-7 cells atdifferent efficiencies. Meanwhile, the generation of the active lentiviruses will allow us to proceed to the subsequent analysis of the effect of regulatory elements in future study.
  10. Shuja’, N., Lazim, M.A., Yap, B.W.
    MyJurnal
    Input-Output analysis provides important information about the structure of a country’s economy. The construction of input-output tables based on detailed census or surveys is a complex procedure requiring substantial financial outlay, human capital, and time. This is the main reason why Malaysia Input-Output (MIO) Table is produced and published on average once every five years. For policy makers past data is not seen as suitable for planning economic policies. The aim of this study is to compare RAS and Euro methods to project input-output tables for Malaysia. The data for the study are MIO table and Gross Domestic Product for the years 2000, 2005 and 2010. The RAS and Euro method were used to project the MIO table 2005 using MIO table 2000 and also projection of MIO table 2010 using MIO table 2005. The projection of I-O tables involved an intensive iterative procedure using Excel Visual Basic programming. The projection performance of RAS and Euro methods were assessed based on Mean Absolute Deviation (MAD), Root Mean Squared Error (RMSE) and Dissimilarity Index (DI). The results show that Euro method performed better than the RAS method in the projection of MIO table.
  11. Shuib, A., Alwadood, Z.
    MyJurnal
    This paper presents a mathematical approach to solve railway rescheduling problems. The approach assumes that the trains are able to resume their journey after a given time frame of disruption whereby The train that experiences disruption and trains affected by the incident are rescheduled. The approach employed mathematical model to prioritise certain types of train according the railway operator’s requirement. A pre-emptive goal programming model was adapted to find an optimal solution that satisfies the operational constraints and the company’s stated goals. Initially, the model minimises the total service delay of all trains while adhering to the minimum headway requirement and track capacity. Subsequently, it maximises the train service reliability by only considering the trains with delay time window of five minutes or less. The model uses MATLAB R2014a software which automatically generates the optimal solution of the problem based on the input matrix of constraints. An experiment with three incident scenarios on a double-track railway of local network was conducted to evaluate the performance of the proposed model. The new provisional timetable was produced in short computing time and the model was able to prioritise desired train schedule.
  12. Shodiya, S., Azhar, A. A., Darus, A. N.
    MyJurnal
    HCFCs, in addition to destroying the ozone layer, have been recognized as a contributing factor that increases global warming. It is widely used as working fluid in window air-conditioning system, where capillary tube serves as an expansion device. Literature reports have shown that no single refrigerant can solve the problem of ozone layer depletion and global warming. Refrigerant HC290/HC600a/HFC407C mixture, an eco-friendly refrigerant, has been recognized as an alternative to HCFC22. The objective of this study is to, for cost effectiveness, develop an empirical correlation to predict the refrigerant HC290/ HC600a/HFC407C mixture mass flow rate using statistical experimental design approach. A review of relevant literature shows that refrigerant’s mass flow rate depends on condensing temperature, degree of subcooling, inner diameter and length of capillary tube. The relationship between the mass flow rate and the four independent variables was established as an empirical mathematical correlation using central composite design (CCD), a response surface methodology (RSM). This empirical correlation was examined using analysis of variance (ANOVA) of 5% level of significance. The results of these analysis showed that the correlation fitted well with the experimental data yielding an average and standard deviation of 1.05% and 2.62%, respectively. The validity of the present correlation was further assessed by comparing it with published empirical correlation in literature and the result showed that the present correlation is consistent.
  13. Shitan, Mahendran, Kok, Wei Ling
    MyJurnal
    Modelling observed meteorological elements can be useful. For instance, modelling rainfall has
    been an interest for many researchers. In a previous research, trend surface analysis was used and
    it was indicated that the residuals might spatially be correlated. When dealing with spatial data, any
    modelling technique should take spatial correlation into consideration. Hence, in this project, fitting
    of spatial regression models, with spatially correlated errors to the annual mean relative humidity
    observed in Peninsular Malaysia, is illustrated. The data used in this study comprised of the annual
    mean relative humidity for the year 2000-2004, observed at twenty principal meteorological stations
    distributed throughout Peninsular Malaysia. The modelling process was done using the S-plus
    Spatial Statistics Module. A total of twelve models were considered in this study and the selection
    of the model was based on the p-value. It was found that a possible appropriate model for the
    annual mean relative humidity should include an intercept and a term of the longitude as covariate,
    together with a conditional autoregressive error structure. The significance of the coefficient of the
    covariate and spatial parameter was established using the Likelihood Ratio Test. The usefulness
    of the proposed model is that it could be used to estimate the annual mean relative humidity at
    places where observations were not recorded and also for prediction. Some other potential models
    incorporating the latitude covariate have also been proposed as viable alternatives.
  14. Shirazi, A.H.S., Muda, M.K.H., Thirumurthy, M.J., Mustapha, F.
    MyJurnal
    This paper presents an improved version of a wireless device embedded with a smart PZT sensor to
    detect flaws and structural defects on selected investigated structure. Smart PZT sensors were used as an
    actuator and sensor, coupled with two XBee’s and one signal generator IC chip. Programme execution on
    transmitting and receiving the ultrasonic guided wave via the PZT sensor had been written in MATLAB.
    The developed source code is basically to receive serial data from one Xbee to another remote Xbee attached
    to the investigated structural system. The refined waveform response is utilised for prognosis of the true
    structural status. The 4-mm simulated holed into one of the aluminium structural plate is benchmarked
    with its pristine condition in validating the effectiveness of the developed SHM wireless module. Results
    showed that the wave is more even in non-defected area and disrupted in affected area. Ultrasonic waves
    increase continuously for non-destructive evaluation and structural health monitoring in various structural
    applications because the guided wave can propagate long distances and reach difficult-to-access regions;
    for inspecting porous and some non-porous materials ultrasonic waves attenuate fast and are very useful.
    Recent advances in ultrasonic wave application model and results are discussed in this paper.
  15. Shin, Tan Seok, Zeenathul Nazariah Allaudin, Mohd. Azmi Mohd. Lila
    MyJurnal
    Adenovirus vector is the most common used vector in clinical gene therapy. The development of adenovirus from the first generation until the helper-dependent adenovirus vector has greatly reduced toxicity and immunogenicity. The helper-dependent adenovirus can also prolong transgene expression. Tissue- or disease-specific approach has been used to improve the specificity of adenoviral vector for cancer gene therapy. This review summarizes some adenoviral gene therapy and targeting approaches available for human cancer as well as animal cancer.
  16. Sheiladevi, S., Rahman, A.
    MyJurnal
    The purpose of this research is to analyse the impact of identified variables to adapt change management
    due to e-learning implementation in Malaysian private higher education institutions focusing on educators’
    perspectives. The conceptual framework was modified in combination of various theories from Systemic
    Change Models and E-learning Cycle Models. A self-administered questionnaire adapted from Siebel
    4.0-2 Survey Questionnaires (SSQ) by Hambling, 2010 was the data collection instrument. The sample
    consisted of educators from private higher education institutions with visions or missions based on
    e-learning implementation in Malaysia. As per findings, through review of the visions and missions,
    the selected private higher education institutions integrated teaching and learning, advancement of the
    knowledge based on e-learning and leadership in service and outreach.
  17. Shazrul Fazry, Malina Kumaran, Nahid Khalili, Ibrahim Mahmood, Herryawan Ryadi Eziwar Dyari, Nur Hidayah Jamar, et al.
    MyJurnal
    The zebrafish (Danio rerio) has become a prevailing vertebrate model for developmental biology studies due to its ease of care, rapid embryogenesis stages development and translucent embryos. In this studies, ATM Kinase and MRN complex role as DNA damage response proteins during embryogenesis was examined by using specific MRN complex (Mirin) and ATM Kinase inhibitors (Ku60019 and Ku55933). To create DNA lesions in zebrafish, embryos at mid-blastula transition (MBT) stage were exposed to inhibitors (Mirin, Ku60019 or Ku55933) and later exposed to UVC irradiation wavelength of between 100 to 280 nm. Hatching but with visible physical deformation was observed for embryos treated with Mirin, Ku60019 or Ku55933 and UVC exposure at concentration of 3μM, 1.5 nM and 3nM or lower, respectively up to 72 hours-post fertilisation (hpf). On the other hand, no deformities were observed for all control as well as mock treated embryos. This study confirmed that DNA damage response proteins are crucial during embryo development to prevent undesired abnormal biological development. Thus, it is proven that protein inhibitors are a cheaper alternative in valuating specific protein roles during embryogenesis compared to both genomic and transcription modification tools.
  18. Shazreen, S., Fathinul Fikri, A.S., Shakher, R., Shahrun Niza, A.S.
    MyJurnal
    The aim of this study was to evaluate the value of MRI spectroscopy and association with the altered glucose metabolism on 18-FDG PET/CT in patients with suspicious breast cancer. Eight selected breast cancer patients with BIRADS 4 or 5 on mammogram were recruited and patients underwent 18F-FDG PET/CT MRI (spectroscopy). The standardise uptake value (SUVmax) was analysed to determine the degree of the altered glucose metabolism on the PET. The metabolites of tumor lesions were measured using in vivo proton MR spectroscopy (MRS) of the breast. There were eight females with a mean age of 55.3±12.2 years with a biopsy result of invasive ductal carcinoma (2), lobular carcinoma (1) and benign lesion (5). There was a significant difference between the mean of the malignant tumour (SUVmax 4.28±3.74 g/ml) and the mean of the benign tumour (SUVmax: 2.33±0.9 g/ml). On the per-lesional basis of the MRS correlate with SUVmax, the suspicious breast tissue exhibited raised creatinine metabolites (mean: 3.39±0.54u) with significant correlation SUVmax mean 3.06±2.34 as compared to N-acetyl Aspartate (NAA), (mean: 2.84±0.99u) and choline (mean: 2.46± 0.70 u). This study showed that high SUVmax was associated with malignant cancer and the high creatinine metabolite that correlated with the SUVmax could potentially be utilised as a surrogate marker in detecting breast cancer.
  19. Sharmila Karim, Zurni Omar, Haslinda Ibrahim, Khairil Iskandar Othman, Mohamed Suleiman
    MyJurnal
    Linear array of permutations is hard to be factorised. However, by using a starter set, the process of listing the permutations becomes easy. Once the starter sets are obtained, the circular and reverse of circular operations are easily employed to produce distinct permutations from each starter set. However, a problem arises when the equivalence starter sets generate similar permutations and, therefore, willneed to be discarded. In this paper, a new recursive strategy is proposed to generate starter sets that will not incur equivalence by circular operation. Computational advantages are presented that compare the results obtained by the new algorithm with those obtained using two other existing methods. The result indicates that the new algorithm is faster than the other two in time execution.
  20. Sharifah Sakinah, Tuan Othman, Jasronita, Jasni, Mohd Nazim, Mohtar
    MyJurnal
    Lightning is a natural phenomenon that generates a high electric field during thunderstorm. It has been
    reported that lightning strikes amid storms can occur around 100 times per second. The atmospheric
    electric field is an imperative parameter during a thunderstorm. Therefore, monitoring the electric field
    and its parameters is the best way for local lightning forecast. The electric field monitoring data can
    validate the accuracy of weather prediction in a local area from meteorology department or by using
    equipment specially designed to measure this electric field that exists when the phenomenon of lightning occurs. In this paper, the relationship between lightning, air humidity and temperature is discussed to understand the post lightning effect on these electric parameters. Additionally, the characteristics of the parameters are observed and analysed.
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