Displaying publications 61 - 80 of 9913 in total

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  1. Muneer Saleh, Ahmad Suhaimi
    MyJurnal
    An instrumental neutron activation analytical (INAA) technique is used for the determination of thirty elements in five coal samples collected from Kapar power station, imported from Indonesia and Australia. Analyses of the samples are being associated with standards. All irradiations were performed in the nuclear reactor of Malaysia Nuclear Agency (MNA). Samples were counted by Hyper Pure Germanium (HPGe) detector for short period irradiations at MNA, while for the long period irradiations the samples were counted at Universiti Kebangsaan Malaysia (UKM). The concentrations of thirty elements have been determined: The major components are Cl, Ca, Mg, K, Fe, Ti and Na with the mean concentrations in the range between 70±69 ppm- 6100±1639 ppm; and the trace elements are Zr, V, Mn , Sc, Cr, Co, As ,Br ,Rb ,Sb ,Ba , La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Hf, Th, U and Ta with the mean concentrations in the range between 0.1381±0.0202 - 69.0±2.8 ppm. The results have been compared to the reported data of eight coal samples from the United States and the reported data of Australian bituminous coal.
  2. Ahmad Syazrin Muhamad
    MyJurnal
    Sound is one of the source of energy generated by vibration and is carried through the air in a form of pressure waves (Frederick, 1975). This pressure waves consist of pulsation or vibration of molecules of an elastic medium such as gas, liquid and even solid (Gerber, 1974). Due to its nature, sound can be irritating when it is excessive. The excessive amount of sound is called noise. Exposure to noise is common to the workers working at the industry. This can lead to hearing loss. Hearing loss is one of the most common health problems in the industrialized world. Working activities have been related to noise exposure due to increase use of machine that generates sounds. Many workers throughout the world experience hazardous noise exposure which is ≥ 85 decibels (dB) (Seter, 1998). Based on the previous study in the European region, most of the employers had difficulties to compensate workers diagnosed with hearing loss or hearing impairment cause by the working nature. (Rachiotis et al., 2006). According to European Survey on Working Conditions, about 7% of the workers considered that their work affects their health in the form of hearing disorders. Occupational risk factors for hearing loss include occupational noise, whole body vibration, work-related diseases and exposure to chemical. In this report, we specified in the noise exposure level of the workers.
  3. Othman, M., Ahmad, K.
    ASM Science Journal, 2007;1(2):181-182.
    MyJurnal
    Comet 17P/Holmes was discovered by Edwin Holmes on 6 November 1892 while he was conducting regular observations of the Andromeda Galaxy (M31). Calculations using observation of its orbits established the perihelion date as 13 June and the orbital period as 6.9 years. The 1899 and 1906 appearances were observed, but the comet was only seen again in 1964. The comet has since been
    observed on every subsequent return.
  4. Ahmad, N.A., Margaret, L.
    JUMMEC, 2008;11(1):33-36.
    MyJurnal
    Oral cavity malignancy reconstructive surgery has advanced from pedicle flaps to microvascular free tissue transfer. Previously, reconstruction of these defects were done using radial forearm free flaps in this centre. We report our experience using anterolateral thigh free flap in a 49 year old lady with squamous cell carcinoma of the tongue. Excision of tumour left a defect which was later reconstructed using microvascular free tissue transfer using the right anterolateral thigh free flap. The flap was well taken up at the recepient site and no evidence of flap failure noted post operatively and on completion of radiotherapy. She was able to maintain comprehensible speech and swallowing ability.
  5. Ahmad Saat, Zaini Hamzah
    MyJurnal
    Clay has been regarded as very important natural industrial materials. All these industries exploit the properties that clay can be molded into any shape and fired to dry without losing its form. A study was carried out on clay samples from eight sites in the north-eastern part of Peninsular Malaysia. The study was accomplished by using X-ray diffraction (XRD) technique. The x-ray diffraction spectra obtained enable the determination of the lattice spacing associated with the types of clay and nonclay minerals present in the samples. Results of the study shows that the major components of clay minerals present in all samples studied are kaolinite and illite. The presence of kaolinite is confirmed by firing test in which the kaolinite diffraction peaks disappeared upon heating the samples at 600 o C. The presence of non-clay minerals such as quartz, mica, feldspar and chlorite are also observed.
  6. Ahmad Naim Ismail
    Movement Health & Exercise, 2012;1(1):39-48.
    MyJurnal
    The increase in weight-lifting performance after resistance training is greater than the increase seen in maximal voluntary isometric contraction (MVC). This discrepancy has been attributed to learning and coordination. The purpose of the present study was to look into the contribution of joint angle specificity, and the specificity of the movement at various speeds in explaining the disproportionate increase in weightlifting strength compared to isometric strength. Eighteen participants completed the study. The quadriceps muscle group of each individual was trained unilaterally on a leg extension machine. Participants performed four sets of ten lifts at a steady pace. A load of 80% of the maximum load (1RM) was prescribed. The MVC of the quadriceps was measured on a strength-testing chair. The length-tension relationship was measured isometrically at 600, 750, 900, and 1050 of knee flexion. Measurement of isokinetic strength at velocities of 450/s, 1800/s and 300/s were made. All measurements were made before and after the training. The eight weeks training resulted in a 33% increased in weights lifted (p < 0.05) that was significantly greater than the gain in isometric MVC (6%). Significant gains in isometric strength were seen at all the joint angle but with no evidence of length specificity. Although there were significant gains in strength at higher velocities, they were not sufficient to explain the increased weight-lifting performance and, in any case, similar gains were seen with the untrained leg where no improvement in weight-lifting
    performance was seen. From the findings it is concluded that angle and velocity specificity could not fully account for the discrepancy between gains in weight-lifting performance compared to isometric strength.
  7. Singh, J., Ahmad, N.
    MyJurnal
    Objective: Lacunar infarct is a small infarct in the distal distribution of deep
    penetrating vessels. A silent stroke is not associated with outward symptoms.
    The objective of this report is to highlight a case of a silent young stroke
    presenting with peduncular hallucinosis.

    Methods: This gentleman was
    thoroughly investigated and was found to have a lacunar infarct of the Pons
    and Occipital Lobe. A further referral to Neurology thereafter; for an in
    depth investigation into the cause of this silent young stroke.

    Results:
    Treatment with low dose antipsychotic resolved the complaints; while the
    episode being transient.

    Conclusion: Organic psychosis is responsive to
    antidopaminergic agents, via action on the Ponto-Geniculo-Occipital
    pathways.
  8. Mas Suryalis Ahmad
    Malaysian Dental Journal, 2017;2017(1):0-0.
    MyJurnal
    Perceived and normatic needs for dental treatment is increasing globally, as patients in various parts of the world demonstrate different patterns of oral diseases (1). Some regions showed an increasing demand for aesthetic dentistry (2), while some demonstrated a rise in procedures relating to tooth preservation and functional restoration (3). In spite of the variable market demands, it is evident that utilisation of oral health care services has improved worldwide, regardless of patients’ socioeconomic status and other personal or environmental circumstances (1). (Copied from article)
  9. Mas Suryalis Ahmad
    Malaysian Dental Journal, 2015;38(2):1-4.
    MyJurnal
    In 2013, the Malaysian Education Blueprint (Higher Education) was developed by the Ministry of Education to guide the transformation process of the education system in this country for the next decade, starting from 2015 (1). The blueprint highlighted core aspirations for Malaysian higher education, which includes rapid expansion of research output and quality (1). This effort is in line with the nation's aspiration to uplift the standard of service provision among healthcare professionals, whose practice should advance on the essence of high quality scientific evidence.(Copied from article)
  10. Nur Laila Sofia Ahmad
    Malaysian Dental Journal, 2015;38(2):36-50.
    MyJurnal
    Full mouth rehabilitation of the severely collapsed dentition is one of the most challenging procedures in restorative dentistry. The treatment aims are not only to restore function with sustainable restorations and to provide patients with an aesthetic smile, but also to conserve the remaining dentition and maintain the health of supporting structures. This case report describes the complete oral rehabilitation of a patient with severely broken down dentition and loss of posterior support. Loss of posterior support will not only result in breakdown of remaining dentition in the anterior region due to occlusal overload, it also adds years to the patient’s appearance. A complete treatment plan was outlined involving multidisciplinary team treatment included sessions of oral hygiene instructions and re-assessments, a diagnostic stage with provisional overlay denture at an increased occlusal vertical dimension (OVD), endodontic treatment and retreatment, crown lengthening as well as implant surgery. Final restoration involved both fixed and removable prostheses. Maintenance review was carried out periodically after completion of treatment for two years and good outcome was observed.
  11. Mas Suryalis Ahmad
    Malaysian Dental Journal, 2016;39(1):1-8.
    MyJurnal
    Collaborative teaching is an educational approach that seeks to involve participation of teachers and learners in achieving learning goals and outcomes in an interactive manner (1). Such approach has been effective in equipping students with knowledge and/or skills via high levels of learning, while allowing interpersonal development such as teamwork, time management, as well as communication and written competencies (2, 3). (Copied from article)
  12. Faid Rahman, Ahmad Ismail
    MyJurnal
    Waterbirds serve as an important bio-indicator of ecosystem changes and have been used widely throughout the world. This is because they exhibit conspicuous and meaningful responses to the changes of the environment around them. Other qualities that make them a good bio-indicator are also highlighted. Thus, important information on their biology and ecology are essential to make informed decisions. This is crucial in order to better conserve them and their habitats. Currently they are facing new challenges that arise from continuous development throughout the world. In addition, many endangered species continue to declines and could be extinct if they are not protected and conserved. The development of artificial habitat such as wetlands to compensate natural habitat loss could be an alternative. However, detailed information on the waterbirds and their interactions with the new environment are needed in order to do so. It is further highlighted that few researches have been conducted and focused on the waterbirds particularly in Malaysia. Thus, we encourage more local young scientists to take up this challenge and equip themselves with the right knowledge and necessary skills as well as to remain relevant with the international research standards. Proper planning, funding and focus should also be considered by the government and local authorities to maximize the impact of the country’s conservation effort.
  13. Musa Ahmad, Narayanaswamy R
    Optical fibre has been used in this study to guide a light from the light source to the probe. A disposable type probe developed in this study consist of a reagent Chrome Azurol S (CAS) immobilised on a polymeric support (XAD-2) which has been coupled to a fibre end using nylon mesh. This sensor was regenerable using fluoride solution with a limit of detection of 1.0 ´ 10-5 M, high reproducibility (relative error of < 5.0%) and can be used for Al(III) determination in water at concentration range of 1.3 ´ 10-5 M - 7.0 ´ 10-4 M. The results obtained using this sensor is comparable to the well established method such as atomic absorption spectrophotometry using graphite furnace. EDTA, phosphate, oxalate, tartrate, Cu(II), Fe(III), Be(II) and Ca(III) were found to interfere during Al(III) determination in water.
    Gentian optik telah digunakan di dalam kajilidikan ini sebagai pemandu cahaya daripada sumber cahaya kepada prob. Prob jenis bolehbuang yang dibina dalam kajian ini terdiri daripada reagen Chrome Azurol S (CAS) yang telah dipegunkan di atas penyokong polimer (XAD-2) dan dipegang olehjaring nilon. Penderia ini boleh dijanakan semula menggunakan larutan fluorida, mempunyai had pengesaran 1.0 ´ 10-5 M, kebolehulangan yang tinggi (ralat relatif < 5.0%) dan boleh digunakan untuk penentuan Al(III) dalam air pada julat kepekatan 1.3 ´ 10-5 M - 7.0 ´ 10-4 M. Keputusan analisis yang diperolehi menggunakan penderia ini adalah bolehbanding dengan kaedah yang telah diterima umum seperti spektrofotometri serapan atom mertggunakan relau grafit. EDTA, fosfat, oksalat, tartrat, Cu(II), Fe(III), Be(II) dan Ca(III) didapati menganggu semasa penentuan Al(III) di dalam air.
  14. Ahmad M, Hasan M
    Sains Malaysiana, 2011;40:1179-1186.
    This paper proposes a new computational method for computing non-monotone functions that take a fuzzy interval as their arguments. The proposed method represents an implementation of optimisation technique into Zadeh’s extension principle. By taking into account the dependency problem that exists in fuzzy environment, the proposed method can avoid the effect of overestimation in computation. This problem usually arises when the same fuzzy interval is computed separately in fuzzy interval computation. The proposed method is simple to use and can be implemented in many practical applications. In order to show the capability of the proposed method, several non-monotone functions with trapezoidal fuzzy intervals are studied.
  15. Ahmad M, Hasan M
    Sains Malaysiana, 2011;40:1179-1186.
    This paper proposes a new fuzzy version of Euler’s method for solving differential equations with fuzzy initial values. Our proposed method is based on Zadeh’s extension principle for the reformulation of the classical Euler’s method, which takes into account the dependency problem that arises in fuzzy setting. This problem is often neglected in numerical methods found in the literature for solving differential equations with fuzzy initial values. Several examples are provided to show the advantage of our proposed method compared to the conventional fuzzy version of Euler’s method proposed in the literature.
  16. Norhayati Ahmad, Sueyoshi H
    Sains Malaysiana, 2012;41:1005-1009.
    Si3N4-TiN composites were prepared by conventional powder processing (SPS1) and in-situ reaction sintering (SPS2). Rapid densification of SPS was achieved for sample SPS1 and SPS2 within a few minutes at low temperature. Sample SPS1 sintered at 1550ºC showed rapid transformation of α to β Si3N4 while for sample SPS2 sintered at 1350ºC, a significant
    degree of α to β Si3N4 transformation was achieved. Homogeneous distribution of equiaxed TiN grains in matrix Si3N4 resulting in high hardness (21.7 GPa) and bending strength (621 MPa) for sample SPS1 sintered at 1550ºC. Elongated TiN grains as the reinforcement of Si
    3N4 matrix composites was found to increase the toughness (8.39 MPa m1/2) of sample
    SPS2 sintered at 1350ºC. The composites prepared by SPS2 sintered at 1250-1350ºC had low electrical resistivity and could be machined by electrical discharge machining (EDM).
  17. Ahmad Puaad Othman
    Computer simulations is now becoming a common feature in many under­graduate physics textbook together with online supplements to supposedly enhance learning and understanding. Many questions arise as to how these computer simulations and online supplements are developed and is it a worthy investment on the part of the physics educators. In this paper we look at the ways how "Physlets" (Physics Applets) are developed for the purpose of the undergraduate physics curriculum. JAVA is the fastest-growing pro­gramming language today. In scientific programming, the JAVA language meets the need for a simpler object-oriented language than C++ but is not yet popular, useful and widely used in very large scale or number crunching physics simulations. One of JAVA applets’s strength is that it is device independent. And for physics learning, simulation applets embedded in World Wide Web pages allow interactive learning and students-programmable demonstrations. We will examine a few physics simulations using JAVA applets that we have developed. We also discuss the various different aspects of using JAVA applets in developing physics simulation. And finally we will look into the reasons as to why it is still not ready for use in intensive physics simulation.
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