Displaying publications 1 - 20 of 363 in total

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  1. Udin, W. S., Ahmad, A., Ismail, Z.
    MyJurnal
    In recent years image acquisition in close range photogrammetry relies on digital sensors such as digital cameras, video cameras, CCD cameras etc that are not specifically designed for photogrammetry. This study is performed to evaluate the compatibility of the digital metric camera and non-metric camera for the purpose of mapping meandering flume, using close range photogrammetric technique and further, to determine the accuracy that could be achieved using such a technique. The meandering flume provides an opportunity to conduct an experimental study in a controlled environment. In this study, the digital images of the whole meandering flume were acquired using a compact digital camera - Nikon Coolpix S560, a Single Lens Reflex (SLR) Nikon D60 and also a metric digital camera Rollei D30. A series of digital images were acquired to cover the whole meandering flume. Secondary data of ground control points (GCP) and check points (CP), established using the Total Station technique, was used. The digital camera was calibrated and the recovered camera calibration parameters were then used in the processing of digital images. In processing the digital images, digital photogrammetric software was used for processes such as aerial triangulation, stereo compilation, generation of digital elevation model (DEM) and generation of orthophoto. The whole process was successfully performed and the output produced in the form of orthophoto. The research output is then evaluated for planimetry and vertical accuracy using root mean square error (RMSE). Based on the analysis, sub-meter accuracy is obtained. It can be concluded that the differences between the different types of digital camera are small . As a conclusion, this study proves that close range photogrammetry technique can be used for mapping meandering flume using both the metric digital camera and non-metric digital camera.
  2. Yusoff, N., Reiko Yap, K.M., Ahmad, A.
    MyJurnal
    This study aims to explore the life experience of the husbands of women who survived breast cancer for more than five years following breast removal. Basic interpretative of qualitative methodology was applied in order to construct the phenomenon of breast cancer from the perspective of husbands. This approach allowed researchers to explore in-depth the experience of husbands in facing breast cancer of their wives. Four themes were identified. These are marital
    challenges, pattern of life, supportive atmosphere and psychological defenses. Health strategies should direct the family member to the specific pathway in order to facilitate them towards the effective action of healthcare at their level. Evidence from this study is a direction for future research and health planning for better health policy.
  3. Ahmad AM
    Singapore Med J, 1995 Dec;36(6):600-5.
    PMID: 8781629
    The purpose of the study is as a preliminary outline of the effectiveness of initiating high-risk individuals into the Health Farm concept in the primary prevention of coronary artery disease (CAD). Thirty-five (35) Army personnel, all male, with risk-factors for CAD were brought together on a Health Farm concept to go through a predesigned ten-day Farm programme comprising CAD risk-assessment, comprehensive medical examination, relevant blood chemistry analysis, physical fitness evaluation, individualised weekly exercise routine, physical fitness workouts, individualised diet, lectures, group discussion and individual counselling. Description of the participants (as measurements of various relevant parameters) are made at the start and as participant-achievement. The results show general participant-compliance to the programme which was reflected by significant changes in weight (p < 0.005), percentile VO2Max (p < 0.005), percentile push-ups (p < 0.005) and girth-difference (p < 0.005). The study showed that the Health Farm concept is effective in initiating high-risk individuals into lifestyles conducive to the primary prevention of CAD. Sustained results towards primary prevention of CAD can be expected with compliance to a long-term follow-up that has been identified and to which participants have been made aware of. Other previous intervention studies are briefly discussed.
  4. Majid, Z., Chong, A., Setan, H., Ahmad, A., Rajion, Z.A.
    MyJurnal
    This paper describes the use of stereophotogrammetry approach to measure and hence identify accurately threedimensional (3D) coordinates of important landmarks on a craniofacial surface. A "novel" technique dubbed as "natural features" technique was employed to accurately compute the 3D coordinates of selected craniofacial landmarks. The natural features technique involves the use of 3D coordinates of the natural features (such as acne, scar, corners of eyes, edge of mouth, point of chin, etc.) that appear on the craniofacial surface as an absolute stereophotogrammetric mapping control points. The 3D coordinates of the natural features were gained using digital photogrammetric bundle adjustment method. Validation of the proposed technique has firstly been carried out using mannequin and finally, it was applied on the real-life human faces. The result shows that the craniofacial landmark measurement accuracy of 0.8mm with one standard deviation can be successfully achieved by the proposed technique.
  5. Mahdi, M.A., Md. Ali, M.I., Ahmad, A., Zamzuri, A.K.
    ASM Science Journal, 2008;2(2):123-127.
    MyJurnal
    In this paper a study on the wideband double-pass Raman fibre amplifier with mirror as the pump reflector is reported. The pump lights at 1435 nm and 1455 nm were launched in a co-directional manner with respect to the input signal. The double-pass direction of the signal was achieved through a fibre loop mirror constructed using an optical circulator. It was shown that multiple signal amplification was achieved without any disturbance of stimulated Brillouin scattering.
  6. Sirat HM, Jamil S, Rahman AA
    Nat Prod Commun, 2009 Sep;4(9):1171.
    PMID: 19831021
    From the rhizomes of Curcuma ochrorhiza, four sesquiterpenes, isofuranodiene, germacrene, furanogermenone and zederone, have been isolated, the structures of which have been elucidated by spectroscopic methods.
  7. Ahmad AA, Hameed BH, Ahmad AL
    J. Hazard. Mater., 2009 Oct 30;170(2-3):612-9.
    PMID: 19515487 DOI: 10.1016/j.jhazmat.2009.05.021
    The purpose of this work is to obtain optimal preparation conditions for activated carbons prepared from rattan sawdust (RSAC) for removal of disperse dye from aqueous solution. The RSAC was prepared by chemical activation with phosphoric acid using response surface methodology (RSM). RSM based on a three-variable central composite design was used to determine the effect of activation temperature (400-600 degrees C), activation time (1-3h) and H(3)PO(4):precursor (wt%) impregnation ratio (3:1-6:1) on C.I. Disperse Orange 30 (DO30) percentage removal and activated carbon yield were investigated. Based on the central composite design, quadratic model was developed to correlate the preparation variables to the two responses. The most influential factor on each experimental design responses was identified from the analysis of variance (ANOVA). The optimum conditions for preparation of RSAC, which were based on response surface and contour plots, were found as follows: temperature of 470 degrees C, activation time of 2h and 14min and chemical impregnation ratio of 4.45.
  8. Rafatullah M, Sulaiman O, Hashim R, Ahmad A
    J. Hazard. Mater., 2009 Oct 30;170(2-3):969-77.
    PMID: 19520510 DOI: 10.1016/j.jhazmat.2009.05.066
    The present study proposed the use of meranti sawdust in the removal of Cu(II), Cr(III), Ni(II) and Pb(II) ions from synthetic aqueous solutions. Batch adsorption studies showed that meranti sawdust was able to adsorb Cu(II), Cr(III), Ni(II) and Pb(II) ions from aqueous solutions in the concentration range 1-200mg/L. The adsorption was favoured with maximum adsorption at pH 6, whereas the adsorption starts at pH 1 for all metal ions. The effects of contact time, initial concentration of metal ions, adsorbent dosage and temperature have been reported. The applicability of Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm was tried for the system to completely understand the adsorption isotherm processes. The adsorption kinetics tested with pseudo-first-order and pseudo-second-order models yielded high R(2) values from 0.850 to 0.932 and from 0.991 to 0.999, respectively. The meranti sawdust was found to be cost effective and has good efficiency to remove these toxic metal ions from aqueous solution.
  9. Ahmad AL, Ismail S, Bhatia S
    Environ. Sci. Technol., 2005 Apr 15;39(8):2828-34.
    PMID: 15884382
    The coagulation-flocculation process incorporated with membrane separation technology will become a new approach for palm oil mill effluent (POME) treatment as well as water reclamation and reuse. In our current research, a membrane pilot plant has been used for POME treatment where the coagulation-flocculation process plays an important role as a pretreatment process for the mitigation of membrane fouling problems. The pretreated POME with low turbidity values and high water recovery are the main objectives to be achieved through the coagulation-flocculation process. Therefore, treatment optimization to serve these purposes was performed using jar tests and applying a response surface methodology (RSM) to the results. A 2(3) full-factorial central composite design (CCD) was chosen to explain the effect and interaction of three factors: coagulant dosage, flocculent dosage, and pH. The CCD is successfully demonstrated to efficiently determine the optimized parameters, where 78% of water recovery with a 20 NTU turbidity value can be obtained at the optimum value of coagulant dosage, flocculent dosage, and pH at 15 000 mg/L, 300 mg/L, and 6, respectively.
  10. Osman, Z., Othman, L., Md Isa, K.B., Ahmad, A., Kamarulzaman, N.
    ASM Science Journal, 2010;4(1):55-61.
    MyJurnal
    In this study polymer electrolytes composed of poly(methyl methacrylate) (PMMA) as a host polymer and ethylene carbonate (EC) as a plasticizer complexed with different lithium salts, i.e. lithium tetrafluoroborate (LiBF4) and lithium triflate (LiCF3SO3) were prepared by the solution casting technique. The conductivities of the films were characterized by impedance spectroscopy. At room temperature, the highest conductivities were 4.07 × 10–7S cm–1 and 3.40 × 10–5 S cm–1 achieved, respectively from the films containing 30 wt% LiBF4 in the PMMA-EC-LiBF4 system and 35 wt% LiCF3SO3 in the PMMA-EC-LiCF3SO3 system. The conductivity-temperature dependence of the films seemed to obey the Arrhenius equation in which the ion transport in these materials was thermally assisted. Scanning electron microscopy analysis showed that the surface of PMMA-EC-LiCF3SO3 film was smooth and homogeneous, hence lithium ions could traverse through the PMMA-EC-LiCF3SO3 film more easily compared to the PMMA-EC-LiBF4 film. X-Ray diffraction studies revealed that complexation had occurred and the complexes formed were amorphous.
  11. Odeyemi OA, Ahmad A
    Microb. Pathog., 2017 Feb;103:178-185.
    PMID: 28062284 DOI: 10.1016/j.micpath.2017.01.007
    This study aimed to compare population dynamics, antibiotic resistance and biofilm formation of Aeromonas and Vibrio species from seawater and sediment collected from Northern Malaysia. Isolates with different colony morphology were characterized using both biochemical and molecular methods before testing for antibiotic resistance and biofilm formation. Results obtained from this study showed that in Kedah, the population of Aeromonas isolated from sediment was highest in Pantai Merdeka (8.22 log CFU/ml), Pulau Bunting recorded the highest population of Aeromonas from sediment (8.43 log CFU/g). It was observed that Vibrio species isolated from seawater and sediment were highest in Kuala Sanglang (9.21 log CFU/ml). In Kuala Perlis, the population of Aeromonas isolated from seawater was highest in Jeti (7.94 log CFU/ml). Highest population of Aeromonas from sediment was recorded in Kampong Tanah Baru (7.99 log CFU/g). It was observed that Vibrio species isolated from seawater was highest in Padang Benta (8.42 log CFU/g) while Jeti Kuala Perlis had highest population of Vibrio isolated from sediment. It was observed that location does not influence population of Aeromonas. The results of the independent t - test revealed that there was no significant relationship between location and population of Vibrio (df = 10, t = 1.144, p > 0.05). The occurrence of biofilm formation and prevalence of antibiotic resistant Aeromonas and Vibrio species in seawater and sediment pose danger to human and aquatic animals' health.
  12. A’attiyyah A.A., Wan Afiqah Syahirah W.G., Kannan, T.P., Suharni M., Ahmad A., Nor Azah M.A.
    MyJurnal
    Medicinal plants have healing properties and are able to synthesize various chemical compounds. These chemicals (also known as phytochemical compounds) play vital roles in determining the pharmacological properties existing in certain plants. The phytochemical compounds present in plants are associated with primary and secondary constituents. Most of the time, the secondary constituents exhibit the bioactivities in plants such as antimicrobial, antioxidant, antidiabetic, antibacterial and anti-inflammatory properties. Some common medicinal plants that have been used in curing various diseases by traditional practitioners in Malaysia are Ficus deltoidea Jack, Andrographis paniculata, Curcuma longa, Clinacanthus nutans and Eurycoma longifolia Jack. This review discusses the morphology, phytochemical compounds and phytochemical properties of selected medicinal plants in Malaysia. The plants of focus have been found to possess anti-cancer and anti-diabetic effects. This review, it is hoped will enable Malaysian researchers to explore further on the potential of these plants in investigating new and novel drugs in the future.
  13. Awang, M.S., Abdul Razak, A.H., Che Ahmad, A., Mohd Rus, R.
    MyJurnal
    Introduction: The purpose of this study is to identify the incidence of clavicle fractures in newborn
    associated with fetal, maternal and process of deliveries in Kuantan General Hospital from June 2012 until
    January 2014. This study is to determine epidemiological data of clavicle fractures, maternal and baby risk
    factors associated with clavicle fractures of newborn and its’ outcome.

    Methods: This is a prospective
    study. 13 patients were identified to fulfill the inclusion criteria of the study. The data of
    sociodemographic, associated fetal and maternal risk factors and the outcomes were recorded using
    proforma. The statistical data analysis was done using SPSS 12.0.

    Results: Out of 20,257 live births at our
    centre during the study period, 13 infants were diagnosed to have clavicle fractures, giving an incidence of
    0.64 per 1000 live births. There were 5 (38.5%) left, 7 (53.8%) right and one (7.7%) bilateral fracture. All
    fractures located at the mid shaft of the clavicle and none have associated brachial plexus injuries. All
    infants were delivered through vaginal delivery (61.5%); five through assisted delivery (instrumental); 2
    (15.4%) forcep and 3 (23.1%) vacuum. Two of the babies developed shoulder dystocia. The average birth
    weight was 3371 grams (SD 0.269) and mean gestational age was 38.7 weeks (SD 1.16). Five of the mothers
    (38.5%) were primigravida and eight (61.5%) were multigravida in which,7 (53.8%)were healthy without
    other co-morbidty, 5 (38.5%) having gestational diabetis and one (7.7%) hypertension. The average maternal
    weight was 62.0 kg and height 1.58 metres with average BMI of 24.16 (3.29SD). All eventually had a
    complete recovery at 6 weeks with clinical and radiological evident of fracture union.

    Conclusions: In
    conclusion, all patients with clavicle fractures were found following vaginal delivery. There were no
    associations between neonatal clavicle fractures with maternal or baby risk factors. All fractures healed
    without any complications.
  14. Majid AAA, Wu DT, Koh CA
    Langmuir, 2017 10 24;33(42):11436-11445.
    PMID: 28926254 DOI: 10.1021/acs.langmuir.7b02642
    In situ rheological measurements for clathrate hydrate slurries were performed using a high pressure rheometer to determine the effect of hydrate particles on the viscosity and transportability of these slurries. These measurements were conducted using a well-characterized model water-in-oil emulsion ( Delgado-Linares et al. Model Water in-Oil Emulsions for Gas Hydrate Studies in Oil Continuous Systems . Energy Fuels 2013 , 27 , 4564 - 4573 ). The emulsion consists of a model liquid hydrocarbon, water, and a surfactant mixture of sorbitane monooleate 80 (Span 80) and sodium di-2-ethylhexylsulfosuccinate (Aerosol OT, AOT). This emulsion was used as an analog to water-in-crude oil (w/o) emulsions and provides reproducible results. The flow properties of the model w/o emulsion prior to hydrate formation were investigated in terms of several parameters including water percentage, temperature and pressure. A general equation that describes the viscosity of the emulsion as a function of the aforementioned parameters was developed. This general equation was able to predict the viscosity of a saturated emulsion at various temperatures and water percentages to within ±13% error. The general equation was then used to analyze the effect of hydrate formation on the transportability of gas hydrate slurries. As for hydrate slurries investigation, measurements were performed using methane gas as the hydrate former and a straight vane impeller as a stirring system. Tests were conducted at constant temperature and pressure (1 °C and 1500 psig of methane) and water percentages ranging from 5 to 30 vol %. Results of this work were analyzed and presented in terms of relative values, i.e., viscosities of the slurries relative to the viscosities of the continuous phase at similar temperature and pressure. In this work, a correlation to predict the relative viscosity of a hydrate slurry at various hydrate volume fractions was developed. Analysis of the developed correlation showed that the model was able to predict the relative viscosity of a hydrate slurry to within ±17% error.
  15. Ahmad AA, Hameed BH
    J. Hazard. Mater., 2010 Mar 15;175(1-3):298-303.
    PMID: 19883979 DOI: 10.1016/j.jhazmat.2009.10.003
    In this work, the adsorption potential of bamboo waste based granular activated carbon (BGAC) to remove C.I. Reactive Black (RB5) from aqueous solution was investigated using fixed-bed adsorption column. The effects of inlet RB5 concentration (50-200mg/L), feed flow rate (10-30 mL/min) and activated carbon bed height (40-80 mm) on the breakthrough characteristics of the adsorption system were determined. The highest bed capacity of 39.02 mg/g was obtained using 100mg/L inlet dye concentration, 80 mm bed height and 10 mL/min flow rate. The adsorption data were fitted to three well-established fixed-bed adsorption models namely, Adam's-Bohart, Thomas and Yoon-Nelson models. The results fitted well to the Thomas and Yoon-Nelson models with coefficients of correlation R(2)>or=0.93 at different conditions. The BGAC was shown to be suitable adsorbent for adsorption of RB5 using fixed-bed adsorption column.
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