Displaying publications 21 - 40 of 839 in total

Abstract:
Sort:
  1. Ahmad, M.B., Hashim, K.B., Mohd Yazid, N., Zainuddin, N.
    MyJurnal
    In this work, hydrogels were prepared from carboxymethyl cellulose (CMC) and 1-vinyl-2-pyrrolidone(VP) by Electron Beam irradiation in the presence of N,N'-methylenebisacrylamide (BIS) as a crosslinkingagent. The parameters studied include stirring time and percentage of crosslinking agent. Hydrogels werecharacterized using Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy(SEM). VP and BIS were found be effective as reinforcement materials to improve the properties ofCMC. Meanwhile, the optimum conditions were 5% BIS and 3 hours of stirring time. The gel fractionincreased when irradiation dose was increased. FTIR confirmed the crosslinking reaction between CMCand VP after the irradiation process by using BIS as the crosslinking agent. TGA thermograms showedchanges in the thermal properties of CMC-VP hydrogels in the presence of different amounts of BIS.
  2. El Aswad, Nadia Ahmed, Mohammad, Thamer Ahmad, Abdul Halim Ghazali, Zainuddin Md Yusoff
    MyJurnal
    Tripoli coastal aquifer, Libya, which is located in a densely urbanised area, is the primary source of water supply in Tripoli city. In the last few decades and due to population growth, more than 100 wells have been drilled in Tripoli aquifer for the purpose of increasing pumping to meet demand on groundwater. The urbanisation at the Tripoli upper aquifer system has reduced the recharge rates and affected the groundwater storage. In this study, changes in groundwater dynamics in Tripoli’s unconfined aquifers were simulated using MODFLOW-2005 code. The model was calibrated and validated using measured and simulated values. Statistical tests such as coefficient of determination, R2 mean error, mean absolute error, and the root mean square error were computed and found to be 0.97, 0.31, 1.70 and 2.32 respectively. The simulation will assist in the assessment of the long term saline water intrusion. Calibrated transient groundwater flow models for the years 2020 – 2100 indicated that this case is likely to occur along pumping profiles with high pumping rates. Simulation results show that the groundwater levels will decline and exceed 12 m in the Southern area while in the Northern area near the coastal line, depletion is continuous and more than 70 wells will face saline water intrusion by the year 2100. Doubling the pumping rate from the wells will accelerate the drop in the groundwater levels and about 98% of the wells will be subjected to high salinity level by 2100. The salinity levels in these wells will make the groundwater unfit for human consumption.
  3. Tan Lee CY, Ngatirin NR, Zainol Z
    MyJurnal
    Personality represents the mixture of features and qualities that built an individual’s distinctive characters including thinking, feeling and behaving. Traditionally, self-assessment method via questionnaire is the most common means to identify personality. Since recommender systems and advertisement
    campaigns have evolved rapidly, personality computing has become a popular research field to provide personalisation to users. Currently, researchers have utilised social media data for automatically predicting personality. However, it is complex to mine the social media data as they are noisy, free-format, and
    of varying length and multimedia. This paper proposes a decision tree C4.5 algorithm to automatically predict personality based on Big Five model. The Big Five Inventory and ZeroR algorithm were included to be served as the baseline for performance evaluation. Experimental evaluation demonstrated that C4.5
    performs better than ZeroR in terms of accuracy.
    Keywords: Big Five, decision tree, personality, social media
  4. Norhafiz Azis, Yee Von Thien, Robiah Yunus, Zaini Yaakub
    MyJurnal
    In recent years, vegetable oil such as Palm Oil (PO) has been identified as a potential alternative dielectric insulating fluid for transformers. It is biodegradable, non-toxic and has high flash and fire points. In this paper, a study on the positive lightning impulse breakdown voltages of PO under non-uniform field is carried out. The testing was carried out using needle-plane electrodes configuration at gap distances of 25 mm and 50 mm. Rising voltage, 1 and 3 shots per step testing methods were used and 3 types of Refined Bleach and Deodorized Palm Oil (RBDPO) and Mineral Oil (MO) were examined. It was found there is no significant effect on the breakdown voltages of all samples. The breakdown voltages of all RBDPO at 50% probability are comparable with MO. At 1% probability and gap distance of 50 mm, the breakdown voltages of all RBDPO are lower than MO.
  5. Taufiq-Yap, Y. H., Ong, P. S., Zainal, Z.
    MyJurnal
    In this work, 10 mol% yttrium-doped ceria powders, Ce0.9Y0.1O1.95, were synthesised using a new mechanical technique, mechanochemical reaction, in which both impact action and shearing forces were applied for efficient fine grinding, subsequently leading to higher homogeneity of the resultant powders. Ce0.9Y0.1O1.95 prepared using this new technique was systematically compared with a sample of the same prepared using conventional solid-state methodology. X-ray diffraction analysis showed all prepared samples were single phase with a cubic fluorite structure. Generally, Y2O3-doped CeO2 electrolytes prepared by mechanochemical reactions were stable at a lower temperature (1100 °C) compared with a sample of the same synthesised using the conventional solid-state method. Characterisations using differential thermal analysis (DTA) and thermogravimetric analysis (TGA) showed no thermal changes and phase transitions, indicating all materials were thermally stable. The electrical properties of the samples investigated by AC impedance spectroscopy in the temperature range 200–800 ˚C are presented and discussed. Scanning electron microscopy (SEM) was used to study the morphology of the materials. Fine-grained powders with uniform grain-size distribution were obtained from the mechanochemical reaction.
  6. Nor Azah Yusof, Zainab Omar
    MyJurnal
    In this study, a simple, selective and sensitive method, for spectrophotometric determination of As(III) with gallocyanine as the sensitive reagent was developed. The wavelength of an analytical measurement, for the determination of As (III), using gallocyanine was at 630 nm with an optimum response at pH 2. The RSD for the reproducibility of 100 ppm As (III) was 2.3%. The LOD was 0.04 ppm with linear dynamic range in As(III) concentration of 0.2 - 1.5 ppm. The developed method has been validated against Atomic Absorption Spectrophotometry (AAS). The interference study of several metal ions was carried out and it revealed that that Mn (II) ion was interfered the most.
  7. Rosilawati Zainol, Sayed Jamaludin Sayed Ali, Zainab Abu Bakar
    MyJurnal
    This paper presents the evaluation of integrated partial match query in Geographic Information Retrieval (GIR). To facilitate the evaluation, Kuala Lumpur tourist related data is used as test collection and is stored in SuperWeb, a map server. Then the map server is customized to enhance its query capability to recognize word in partial or case sensitive between layers of spatial data. Query keyword is tested using the system and results are evaluated using experiments on sample data. Findings show that integrated partial match query provides more flexibility to tourist in determining search results.
  8. Usubamatov, R., Qasim, A.Y., Zain, Z.M.
    MyJurnal
    Wind energy has often been touted as one of the most reliable sources of renewable energy that should be used for people. Today, wind energy (mainly by propeller type wind turbines) produces less than one percent of the total energy used worldwide. Practically, a standard three-blade propellers efficiency of use of the wind energy is around twenty percents and this is due to its design and shape that use the wind lift force and a rotating turbine. In addition, these turbines are quite expensive due to the complex aerodynamic shape of the propellers which are made of composite materials. The new world boom for wind turbines obliges inventors to create new wind turbine designs that have high efficiency and are better than any known design. This paper proposes the new patented invention of the vane-type wind turbine which uses wind energy more efficiently and is only dependent on the acting area of the vanes. The vane wind turbine was designed to increase the output of a wind turbine that uses kinetic energy of the wind. Due to its high efficiency, simple construction and technology, the vane wind turbine can be used universally, apart from the fact that it is made from cheap materials. The new design of the vane-type wind turbine has quite small sizes than the propeller type one of same output power.
  9. Ariffin Abas, Abdul Halim Shaari, Zainal Abidin Talib, Zaidan Abdul Wahab
    MyJurnal
    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.
  10. Muhammad Shukri Senwan, Muhd Fauzi Safia, Zainon Mohd Noor, Zaidah Zainal Ariffin
    MyJurnal
    Aspergillus sp. is an extremely resilient species that can be found everywhere in the environment and
    is present abundantly in water and soil. The defining characteristic of Aspergillus sp. is their extensive
    hyphal network which enable them to survive anywhere, even in very harsh conditions. This study was
    carried out to isolate the filamentous fungi from peat soil of animal agricultural farm and characterise
    them based on their morphological and molecular characteristics. Growth rate of each isolated fungi was
    also evaluated in order to determine the period of maturity for each fungi. Soil samples were collected,
    weighed and then dissolved in sterile distilled water. The samples were serially diluted and spread
    onto potato dextrose agar (PDA) for isolation. Different isolated colonies that were morphologically
    different from each plate was purified and sub-cultured onto new media for macroscopic and microscopic
    identifications. For molecular identification, a conventional technique was used in genomic DNA
    extraction of filamentous fungi due to their thick cell wall and presence of surface proteins protecting the
    fungus. These characteristics make it difficult to harvest the genomic DNA. Polymerase chain reaction
    (PCR) was carried out using internal transcribed spacer primers; ITS1 (forward) and ITS4 (reverse).
    The morphological identification and molecular
    technique showed that majority of these isolated
    fungi are Aspergillus sp.
  11. Noraishah Othman, Siti Kartom Kamarudin, Muhd Noor Md Yunus, Abd. Halim Shamsuddin, Siti Rozaimah, Zahirah Yaakob
    MyJurnal
    The production of carbon dioxide from Karas woods under argon atmosphere was investigated using a direct pyrolysis-combustion approach. Direct burning was used in this study, using argon for yrolysis and oxygen during combustion to look at the yield of carbon dioxide, produced at different parameters, such as the temperature, retention time and flow rate of argon, as the carrier gas. In this study, a new methodology, 23 response surface central composite design was successfully employed for the experimental design and analysis of results. Central composite experimental design and response surface method were utilized to determine the best operating condition for a maximum carbon dioxide production. Appropriate predictable empirical linear model was developed by incorporating interaction effects of all the variables involved. The results of the analysis revealed that linear equation models fitted well with the experimental for carbon dioxide yield. Nevertheless, the R-Squared obtained using the direct pyrolysis-combustion was 0.7118, indicating that the regression line was not at the best-fitted line.
  12. Mohd. Sanusi Che Kadir, Jamaliah Md. Jahim, Nurina Anuar, Mohd. Sobri Takrif, Zahira Yaakub
    MyJurnal
    In this study, an anaerobic mesophilic bacterial strain, namely Clostridium butyricum KBH1, was isolated from a natural source. This strain grew well and produced biogas with an average hydrogen concentration of 60% (v/v) in the Reinforced Clostridial Media (RCM). To study the basic nutrient requirements, three main nutrients namely peptone (Pep), yeast extracts (Yes) and glucose (Glu) were chosen as factors, using an experimental design. The experiments were run according to 23 Full Factorial Design, followed by the Response Surface Method (RSM). The fermentation was performed in 30 ml serum bottles with 20 ml working volume in a sterile and anaerobic condition at 37°C with 5% inoculums. The results from the Analysis of Variance (ANOVA) for the factorial design showed that all the three factors had significantly affected the gas production by the C. butyricum. The response surface plot of the gas production by C. butyricum showed that the gas production could be enhanced by increasing peptone and yeast extract concentrations up to 15 g/l and 24 g/l respectively, without showing any substrate inhibition. Meanwhile, the glucose concentration showed an optimum at the middle point (8 g/l) with possible substrate inhibition at a high concentration (12 g/l). The total biogas production could be correlated to the three factors, using the quadratic equation: Gas =0.17 + 7.11Glu - 0.02Pep + 0.77Yes - 0.53Glu2 + 0.09Glu*Pep. The experimental results showed that the strain could grow well in substrate with high organic nitrogen content such as POME and might be not suitable for substrate with high sugar content due to substrate inhibition.
  13. Mohd Ashraf Ahmad, Zaharuddin Mohamed
    MyJurnal
    This paper presents investigations into the development of control schemes for end-point vibration
    suppression and input tracking of a flexible manipulator. A constrained planar single-link flexible manipulator is considered and the dynamic model of the system is derived using the assumed mode method. To study the effectiveness of the controllers, a Linear Quadratic Regulator (LQR) was initially developed for control of rigid body motion. This is then extended to incorporate a noncollocated PID controller and a feedforward controller based on input shaping techniques to control vibration (flexible motion) of the system. For feedforward controller, positive and modified specified negative amplitude (SNA) input shapers are proposed and designed based on the properties of the system. Results from the simulation of the manipulator responses with the controllers are presented in time and frequency domains. The performances of the control schemes are assessed in terms of level of vibration reduction, input tracking capability and time response specifications. Finally, a comparative assessment of the control techniques is presented and discussed.
  14. Abas, M.F., Aftab, S.M.A., Rafie, A.S.M., Ahmad, K.A., Yusoff, H.
    MyJurnal
    The purpose of this research is to gain initial knowledge and to predict the sustainability of an all-weather
    Micro-Aerial-Vehicle (MAV). The observed parameters are: the maximum coefficient of lift, CL and the
    changes in CL after impact, the fluctuation of CL upon entering simulated rain environment, and length of
    stability recovery in terms of time and flapping cycle, t and t/T, at flapping frequencies of 8, 16, and 24
    Hz, at t/T = 3/8 and 7/8. At 24 Hz, the increase in peak CL value after impact of entering rain environment
    is 0.59. The average fluctuations in CL occurred when entering the rain environment are 410.263. The
    stability recovery time recorded is 0.006 seconds. Small birds (especially hummingbirds) have a very
    high flapping frequency that enables them to efficiently withstand external disturbances caused by nature
    and to instantly adapt to new environments.
  15. Noor Mohamad Amin Salleh, Dayangku Kamilah Pengiran Ismail, Yong Soon Kong
    MyJurnal
    Heavy metals from mining sites can contribute to adverse health and environmental issues. Conventional liming practice depletes natural limestone deposits. Blood cockle shell (BCS) and palm kernel shell (PKS) calcination produced alkaline ash to immobilize heavy metals in soil. This study investigates the acid neutralizing capacity (ANC) of calcined BCS and PKS composites. BCS and PKS composites were prepared at various weight ratios (i.e. 1:0, 1:1, 1:5, 1:10, and 0:1) and were combusted for 1 hour at 400°C and 900°C, respectively. BCS and PKS composites were determined by its yield, pH, and ANC. The combustion characteristics for composites was conducted using thermogravimetric analysis (TGA). Elemental analysis was conducted using X-ray fluorescence (XRF) spectroscopy. Fourier transform infra-red (FTIR) was conducted for functional groups analysis. Ash content of composites increased when the portion of PKS feedstock is decreased. Increasing combustion temperature from 400°C to 900°C reduced the ash contents. The pH of raw and combusted composite (at 400°C) decreased as the portion of PKS feedstock is increased. Calcined composites at 900°C have slightly different pH value except for 0:1 sample. ANC value increased as PKS portion in composites reduced. Higher content of calcium oxide (CaO) in the composites increased the ANC value.
  16. Lee, Elaine, Neoh, Phene Pei Nee, Lee, Huei Hong, Wong, Sie Chuong, Wong, Tze Jin, Koo, Lee Feng, et al.
    MyJurnal
    Parboiling process has been widely implemented in brown rice processing, but its effect on in vitro physiological antioxidant capacity of brown rice was not known. In this study, an in vitro method simulating the human physiological conditions was used to investigate the effect of parboiling on antioxidant capacity of brown rice in three Bario rice varieties. In this method, bacterial inocula were prepared from rat cecal contents. Results showed that parboiling process gave significant impacts on in vitro physiological antioxidant capacity of brown rice. The process improved total phenolic content at small intestine (Adan Halus), DPPH scavenging activity at both small and large intestines (Adan Halus and Bario Merah) and ferrous ion-chelating activity at large intestine (Bario Hitam). However, changes in antioxidant capacity were variety dependent, possibly due to different bran pigmentation. These suggested that parboiling process could improve physiological antioxidant capacity with in vitro simulation at small and large intestines by selecting a suitable rice variety and parboiled brown rice could offer good antioxidant properties to maintain physiological health.
  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. Lim, Kean Pah, Abdul Halim Shaari, Chen, Soo Kien, Ng, Siau Wei, Zalita Zainuddin, Ye, Chau Yuen
    MyJurnal
    A series of polycrystalline samples (La1-xSmx)0.67Sr0.33MnO3 (X=0.00, 0.05 and 0.10) were prepared using the conventional solid-state reaction method. The XRD analysis indicated that all the samples were fully crystalline and in a single phase with a rhombohedral structure after a sintering at 1200ºC for 24 hours in air. Meanwhile, the Atomic Force Microscopy measurements showed that a small amount of Sm doping in La sites affected the grain growth and this might affect the grain boundary layer, thus resulting in the reduction of the Curie temperature, TC. Extrinsic magnetoresistance (MR) was observed for all the samples with a large negative MR at low field (0-0.1 or 0.2T) region, followed by a slower varying MR at high field (0.1 or 0.2-1T). The highest low-field MR value of -4.6% (at 0.1T) and -6.1% (at 0.2T) were observed for sample X=0.10 and X=0.05, respectively. Hence, these indicated that the extrinsic MR was grain size dependent and was therefore enhanced with a small amount of Sm substitution in La sites.
  19. Hazirah, A., Loong, Y.Y., Rushdan, A.A., Rukman, A.H., Yazid, M.M.
    MyJurnal
    Clostridium difficile can cause severe diseases with significant morbidity and mortality in infected patients.
    The rate of Clostridium difficile infection is high in North America and European countries. Metronidazole
    and vancomycin have been recommended as the treatments of choice since 1990s. Recurrent infection
    due to Clostridium difficile is common after several days of antibiotic administration. Probiotics have
    been used in these patients as an adjunct treatment with some successful findings. However, a detailed
    investigation on the use of probiotic for infected patients is still needed, particularly for its real efficacy.
  20. Mohd Asri IA, Abd Rani NA, Dzulkifli Z, Muhamad Jamil MI, Ahmad Saman MS, Yasin SM
    MyJurnal
    Tobacco use is one of the largest causes of preventable diseases across the world. It is interesting to note that second-hand smoke exposure is a major public health problem in Malaysia. The objectives of this study are first, to explore the perspectives of pregnant mothers whose partners are smokers, and second, to explore barriers and facilitators to creating a smoke-free environment in their home. This study uses a qualitative method in analysing the experiences of 15 pregnant mothers taken from a specialist healthcare centre in Sungai Buloh, Malaysia. It discusses the perspectives of these pregnant mothers towards their partners’ smoking habits, as well as the barriers and facilitators in creating a smoke-free home. From the interviews, it became apparent that pregnant mothers despised their partners’ smoking habits due to smoke odour, lack of money, and poor health. The barriers in creating a smoke-free home include the attitude of the smoking spouse, difficulty in weaning off the habit, excessive encouragement by a spouse, difficultly in advising a smoking spouse, influences from friends, and wrong perceptions. Meanwhile, the facilitators towards creating a smoke-free home are illnesses developed through smoking, multiple reminders from family members, and nicotine replacement therapy (NRT) were perceived to work on certain smokers and habitual cues in quitting smoking. The transition process towards making homes smoke-free is complex and individualistic; healthcare professionals may need to tailor strategies to take into account the specific contexts of each individual. More education programmes on the impacts of smoking and second-hand smoke exposures to family members and smoking cessation are needed for both pregnant mothers and their smoking partners.
    Study site: Gynaecology Clinic, public teaching hospital, Malaysia
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links