Displaying publications 1 - 20 of 289 in total

  1. Mahdi RI, Gan WC, Abd Majid WH
    Sensors (Basel), 2014;14(10):19115-27.
    PMID: 25317763 DOI: 10.3390/s141019115
    Ferroelectric poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer 70/30 thin films are prepared by spin coating. The crystalline structure of these films is investigated by varying the annealing temperature from the ferroelectric phase to the paraelectric phase. A hot plate was used to produce a direct and an efficient annealing effect on the thin film. The dielectric, ferroelectric and pyroelectric properties of the P(VDF-TrFE) thin films are measured as a function of different annealing temperatures (80 to 140 °C). It was found that an annealing temperature of 100 °C (slightly above the Curie temperature, Tc) has induced a highly crystalline β phase with a rod-like crystal structure, as examined by X-ray. Such a crystal structure yields a high remanent polarization, Pr = 94 mC/m2, and pyroelectric constant, p = 24 μC/m2K. A higher annealing temperature exhibits an elongated needle-like crystal domain, resulting in a decrease in the crystalline structure and the functional electrical properties. This study revealed that highly crystalline P(VDF-TrFE) thin films could be induced at 100 °C by annealing the thin film with a simple and cheap method.
    Matched MeSH terms: X-Rays
  2. Sabar Bauk, Abd. Aziz Tajuddin
    The linear and the mass attenuation coefficients of Rhizophora spp. wood in the photon energy range of 11.22 - 28.43 keV were determined. This was done by studying the attenuation of x-ray fluorescent (XRF) photons from selenium, molybdenum, silver and tin targets. Both the Kα and Kβ peaks were utilised. The results were compared with theoretical values for average breast tissues for youngage, middle-age and old-age groups calculated by using a XCOM computer programme. The mass attenuation coefficient of Rhizophora spp. was found to be close to that of the calculated young-age breast in this photon energy range.
    Matched MeSH terms: X-Rays
  3. Khairiah Yazid @ Khalid, Roslan Yahya, Nadira Kamarudini, Mohd. Zaid Abdullah, Mohd Ashhar Khalid, Abdul Aziz Mohamed
    Detection and analysis of resin is particularly significant since the commercial value of agarwood is related to the quantity of resins that are present. This article explores the potential of a scanning electron microscope in combination with new non-destructive 3D visualization technique, X-ray micro-computed tomography, as imaging tools to visualize micro-structure resin in agarwood. These techniques were used to compare two samples of agarwood chips: high grade and low grade. From the results, it can be concluded that a wood cell filled with resin deposit have a higher attenuation. It can be shown that the combination of scanning electron microscopy and micro-CT can offer high resolution images concerning the localization and structure of resin inside Agarwood. While the second allows the 3D investigation of internal structure of agarwood, the first technique can provide details 2D morphological information. These imaging techniques, although sophisticated can be used for standard development especially in grading of agarwoodlbr commercial activities.
    Matched MeSH terms: X-Rays
  4. Kamal, I., Salehhon, N., Hashim, S., Musa, Y., Abdul Karim, M. K.
    The aimed of this study is to estimate the entrance surface dose (ESD) of routine chest X-ray (CXR) examination and to compare the direct and indirect measurement. This study also extended to relate with the patients body thickness and established lifetime attributable risk (LAR) of the examinations. A total of 101 CXR examinations in posteroanterior (PA) projections were selected
    as subjects and data, such as patient habitus and scanning acquisition parameters were recorded. The mean ESD value obtained from the TLD-100 and the software calculation was 0.31 mGy and 0.17 mGy, respectively. The percentage deviation obtained ranged from 25.5% to 61.3%. In comparison with the national diagnostic reference level (DRL), the mean values of ESD obtained from this study were lower by a factor of 3. Furthermore, it was observed that the mean absorbed dose of the adrenals, kidneys, lungs, oesophagus, and heart walls were lower as compared to the ESD value. The examinations were only associated with very low risk of cancer incidence and mortality. Hence, the results of this study suggested a need for standardisations of the personnel training to perform X-ray examinations according to ALARA principles.
    Matched MeSH terms: X-Rays
  5. Zaini Hamzah, Wan Noorhayani Wan Rosdi, Abdul Khalik Wood
    Well water is a renewable natural resources and one of the drinking water sources. The well water may constituted of dissolved essential chemicals such as K+, Ca''+ and Na+ ; and natural radionuclides such as radioisotopes from uranium-thorium decay series. The geology and mineral composition of the soil will determined the kinds and levels of chemical contents in the groundwater resources. The water flows through the geological formation and dissolved the chemicals before reaching the aquifers. To evaluate how much chemicals and natural radioactive in the water resources, a study has been carried out. Well water samples in this study were taken from 3 districts in Kelantan, which is Bachok, Machang and Kuala Krai. Similarly, in situ water quality parameters were measured using YSI portable water quality parameter include pH, salinity, dissolve oxygen(DO), conductivity, turbidity and total dissolved solids(TDS). The concentrations of K', Ca" and Na' were determined using Energy Dispersive X-ray Fluorescence (EDXRF). Five ml of filtered sample was pipette into the sample cup and, irradiated and measured for 100 seconds counting times. The type of filter used for measuring If+ and Cat{ was Al-thin and default for Nat The ranged of concentration of Kt Ce and Na+ is 23.04-251.89, 3.12-.45.41, and 3.71-125.75 ppm, respectively.
    Matched MeSH terms: X-Rays
  6. Memon AH, Ismail Z, Aisha AF, Al-Suede FS, Hamil MS, Hashim S, et al.
    PMID: 25530783 DOI: 10.1155/2014/470179
    Syzygium campanulatum Korth is an equatorial, evergreen, aboriginal shrub of Malaysia. Conventionally it has been used as a stomachic. However, in the currently conducted study dimethyl cardamonin or 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC) was isolated from S. campanulatum Korth, leaf extract. The structural characterization of DMC was carried out by making use of various techniques including UV, IR, NMR spectral followed by LC-MS, and X-ray crystallographic techniques. For determining the purity of compound, highly effective techniques including TLC, HPLC, and melting point were used. The cytotoxicity of DMC and three different extracts of S. campanulatum was evaluated against human colon cancer cell line (HT-29) by three different assays. DMC and ethanolic extract revealed potent and dose-dependent cytotoxic activity on the cancer cell line with IC50 12.6 and 90.1 µg/mL, respectively. Quite astonishingly to our knowledge, this is the very first report on S. campanulatum as being a rich source (3.5%) of DMC, X-ray crystallography, and anticancer activity on human colon cancer cells.
    Matched MeSH terms: X-Rays
  7. Suhaily Amran, Ahmad Sayuti Zainal Abidin, Shoffian Amin Jaafar, Mohd Talib Latif, Abdul Mutalib Leman
    There are several alternative sampling and analytical methods available for the determination of respirable
    crystalline silica exposure among workers. The commonly used ones are, (1) NIOSH Manual Analytical Method
    No.7500(NMAM 7500) which is Silica, crystalline, by X-ray difractometer via filter deposition(NIOSH 2003), and
    (2) MDHS 101 (Methods for the Determination of Hazardous Substances (MDHS) Guidance No.101: Respirable
    crystalline silica in respirable airborne dust). The aim of this study is to compare applicability of respirable crystalline
    silica sampling and analysis between method MDHS 101 and NMAM 7500. Laboratory procedures will be performed
    strictly based on MDHS 101 and NMAM 7500. Both methods apply X-ray diffraction as analytical technique with
    many variations on sampling techniques and laboratory preparations. Quality assurance values such as detection
    limits, accuracy and precision are derived from both data and will be compared to determine which of the method
    establishes better quality assurance. The method which establishes better quality assurance will be recommend to be
    used in Malaysian respirable crystalline silica monitoring programme. The strength of this research lies on its potential
    to provide local capabilities in analysis of respirable crystalline silica in Malaysian setting.
    Matched MeSH terms: X-Rays
  8. Zainudin LD, Abdul Hafidz MI, Zakaria AF, Mohd Zim MA, Ismail AI, Abdul Rani MF
    Respirol Case Rep, 2016 Mar;4(1):19-21.
    PMID: 26839696 DOI: 10.1002/rcr2.143
    We report a case of a 34-year-old lady with past history of asthma and pulmonary tuberculosis, who presented 5 weeks pregnant with acute dyspnea. Her chest X-ray showed left-sided complete lung collapse and concomitant right-sided pneumothorax. The pneumothorax was initially managed conservatively with a chest tube but due to its persistence despite suction, was subsequently changed to a Pneumostat(TM), with which she was later discharged. She had a normal echocardiography (ejection fraction [EF] 67%) at 5 weeks of gestation but developed pulmonary hypertension (EF 55%, pulmonary arterial pressure 40.7 mmHg) as the pregnancy progressed. She delivered a healthy baby at 35 weeks via elective lower section caesarean section with spinal anesthesia. We followed her up postnatally and noted the presence of left-sided pulmonary embolism, hypoplastic left lung, and left pulmonary artery. The management of this complex case involved a multidisciplinary effort between general medical, respiratory, obstetric, and cardiothoracic teams.
    Matched MeSH terms: X-Rays
  9. Bradley DA, Siti Rozaila Z, Khandaker MU, Almugren KS, Meevasana W, Abdul Sani SF
    Appl Radiat Isot, 2019 May;147:105-112.
    PMID: 30852298 DOI: 10.1016/j.apradiso.2019.02.016
    We explore the utility of controlled low-doses (0.2-100 Gy) of photon irradiation as initiators of structural alteration in carbon-rich materials. To-date our work on carbon has focused on β-, x- and γ-irradiations and the monitoring of radiotherapeutic doses (from a few Gy up to some tens of Gy) on the basis of the thermoluminescence (TL) signal, also via Raman and X-ray photo-spectroscopy (XPS), providing analysis of the dose dependence of single-walled carbon nanotubes (SWCNT). The work has been extended herein to investigate possibilities for analysis of structural alterations in graphite-rich mixtures, use being made of two grades of graphite-rich pencil lead, 8H and 2B, both being in the form produced for mechanical pencils (propelling or clutch pencils). 2B has the greater graphite content (approaching 98 wt %), 8H being a mixture of C, O, Al and Si (with respective weight percentages 39.2, 38.2, 9.8 and 12.8). Working on media pre-annealed at 400 °C, both have subsequently been irradiated to penetrating photon-mediated doses. Raman spectroscopy analysis has been carried out using a 532 nm laser Raman spectrometer, while for samples irradiated to doses from 1 to 40 Gy, XPS spectra were acquired using Al Kα sources (hv ∼1400 eV); carbon KLL Auger peaks were acquired using 50 eV Pass Energy. At these relatively low doses, alterations in order-disorder are clearly observed, defect generation and internal annealing competing as dominating effects across the dose range.
    Matched MeSH terms: X-Rays
  10. Bradley DA, Zubair HT, Oresegun A, Louay GT, Ariffin A, Khandaker MU, et al.
    Appl Radiat Isot, 2018 Nov;141:176-181.
    PMID: 29673719 DOI: 10.1016/j.apradiso.2018.02.025
    In previous work we investigated the real-time radioluminescence (RL) yield of Ge-doped silica fibres and Al2O3 nanodot media, sensing electron- and x-ray energies and intensities at values familiarly obtained in external beam radiotherapy. The observation of an appreciable low-dose sensitivity has given rise to the realisation that there is strong potential for use of RL dosimetry in diagnostic radiology. Herein use has been made of P-doped silica optical fibre, 2 mm diameter, also including a 271 µm cylindrical doped core. With developing needs for versatile x-ray imaging dosimetry, preliminary investigations have been made covering the range of diagnostic x-ray tube potentials 30 kVp to 120 kVp, demonstrating linearity of RL with kVp as well as in terms of the current-time (mAs) product. RL yields also accord with the inverse-square law. Given typical radiographic-examination exposure durations from tens- to a few hundred milliseconds, particular value is found in the ability to record the influence of x-ray generator performance on the growth and decay of beam intensity, from initiation to termination.
    Matched MeSH terms: X-Rays
  11. Yunos MA, Hussain SA, Yusoff HM, Abdullah J
    Appl Radiat Isot, 2014 Sep;91:57-61.
    PMID: 24907683 DOI: 10.1016/j.apradiso.2014.05.015
    Radioactive particle tracking (RPT) has emerged as a promising and versatile technique that can provide rich information about a variety of multiphase flow systems. However, RPT is not an off-the-shelf technique, and thus, users must customize RPT for their applications. This paper presents a simple procedure for preparing radioactive tracer particles created via irradiation with neutrons from the TRIGA Mark II research reactor. The present study focuses on the performance evaluation of encapsulated gold and scandium particles for applications as individual radioactive tracer particles using qualitative and quantitative neutron activation analysis (NAA) and an X-ray microcomputed tomography (X-ray Micro-CT) scanner installed at the Malaysian Nuclear Agency.
    Matched MeSH terms: X-Rays
  12. Muhammad A, Yusof NA, Hajian R, Abdullah J
    Sensors (Basel), 2016;16(1).
    PMID: 26805829 DOI: 10.3390/s16010056
    In this work, a novel electrochemical sensor was fabricated for determination of amoxicillin in bovine milk samples by decoration of carboxylated multi-walled carbon nanotubes (MWCNTs) with gold nanoparticles (AuNPs) using ethylenediamine (en) as a cross linker (AuNPs/en-MWCNTs). The constructed nanocomposite was homogenized in dimethylformamide and drop casted on screen printed electrode. Field emission scanning electron microscopy (FESEM), energy dispersive X-Ray (EDX), X-Ray diffraction (XRD) and cyclic voltammetry were used to characterize the synthesized nanocomposites. The results show that the synthesized nanocomposites induced a remarkable synergetic effect for the oxidation of amoxicillin. Effect of some parameters, including pH, buffer, scan rate, accumulation potential, accumulation time and amount of casted nanocomposites, on the sensitivity of fabricated sensor were optimized. Under the optimum conditions, there was two linear calibration ranges from 0.2-10 µM and 10-30 µM with equations of Ipa (µA) = 2.88C (µM) + 1.2017; r = 0.9939 and Ipa (µA) = 0.88C (µM) + 22.97; r = 0.9973, respectively. The limit of detection (LOD) and limit of quantitation (LOQ) were calculated as 0.015 µM and 0.149 µM, respectively. The fabricated electrochemical sensor was successfully applied for determination of Amoxicillin in bovine milk samples and all results compared with high performance liquid chromatography (HPLC) standard method.
    Matched MeSH terms: X-Rays
  13. Rasheed M, Jawaid M, Karim Z, Abdullah LC
    Molecules, 2020 Jun 18;25(12).
    PMID: 32570929 DOI: 10.3390/molecules25122824
    Bamboo fibers are utilized for the production of various structures, building materials, etc. and is of great significance all over the world especially in southeast Asia. In this study, the extraction of microcrystalline cellulose (MCC) was performed using bamboo fibers through acid hydrolysis and subsequently different characterizations were carried out using various advanced techniques. Fourier transform infrared (FTIR) spectroscopy analysis has indicated the removal of lignin from MCC extracted from bamboo pulp. Scanning Electron Microscopy (SEM) revealed rough surface and minor agglomeration of the MCC. Pure MCC, albeit with small quantities of impurities and residues, was obtained, as revealed by Energy Dispersive X-ray (EDX) analysis. X-ray diffraction (XRD) indicates the increase in crystallinity from 62.5% to 82.6%. Furthermore, the isolated MCC has slightly higher crystallinity compared to commercial available MCC (74%). The results of thermal gravimetric analysis (TGA) demonstrate better thermal stability of isolated MCC compared to its starting material (Bamboo fibers). Thus, the isolated MCC might be used as a reinforcing element for the production of green composites and it can also be utilized as a starting material for the production of crystalline nanocellulose in future.
    Matched MeSH terms: X-Rays
  14. Ibrahim N, Baqiah H, Abdullah M
    Sains Malaysiana, 2013;42:961-966.
    High quality indium oxide and iron doped indium oxide nanocrystalline films were prepared by the sol-gel method followed by a spin coating technique. The samples were characterized by an X-ray diffractometer, an atomic force microscopy and a UV-vis spectroscopy. All samples had good crystallinity with a preferred orientation in the (222) direction. The crystallite size increased from 12.1 nm for the pure sample to 16.1 nm for the sample with x=0.35 and then decreased to 12.1 nm for the sample with x=0.45. All samples contained nanometer grain sizes with a smooth surface. All films showed a high transmission of over 91% in the wavelength range of 200-800 nm.
    Matched MeSH terms: X-Rays
  15. Mohd Chachuli SA, Hamidon MN, Mamat MS, Ertugrul M, Abdullah NH
    Sensors (Basel), 2018 Aug 01;18(8).
    PMID: 30071579 DOI: 10.3390/s18082483
    High demand of semiconductor gas sensor works at low operating temperature to as low as 100 °C has led to the fabrication of gas sensor based on TiO₂ nanoparticles. A sensing film of gas sensor was prepared by mixing the sensing material, TiO₂ (P25) and glass powder, and B₂O₃ with organic binder. The sensing film was annealed at temperature of 500 °C in 30 min. The morphological and structural properties of the sensing film were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The gas sensor was exposed to hydrogen with concentration of 100⁻1000 ppm and was tested at different operating temperatures which are 100 °C, 200 °C, and 300 °C to find the optimum operating temperature for producing the highest sensitivity. The gas sensor exhibited p-type conductivity based on decreased current when exposed to hydrogen. The gas sensor showed capability in sensing low concentration of hydrogen to as low as 100 ppm at 100 °C.
    Matched MeSH terms: X-Rays
  16. Shakinah Salleh, Affrida Abu Hassan, Shuhaimi Shamsudin, Yahya Awang, Ab. Kahar Sandrang, Abdullah, Thohirah Lee
    Chrysanthemum morfolium is an important temperate cut flower and potted plant for Malaysian local market and exporter. Considering chrysanthemum as a popular vegetatively propagated ornamental plant, induce mutations for breeding purposes are more beneficial. Several of physical mutagens have been used in mutation breeding including x-rays, gamma rays and ion beams. Gamma rays and ion beams are from two different linear energy transfer (LET) which are low and high, respectively. The objective of this study was to compare the effectiveness of acute gamma and ion beam irradiation in generating flower colour mutations on nodal explants of Chrysanthemum morifblium cv. Reagan Red'. The nodal explants were irradiated with acute gamma (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110 and 120 Gy) and ion beam (0, 0.5, 1.0, 2.0, 3.0, 5.0, 8.0, 10, 15, 20 and 30 Gy). The optimal dose for in vitro shoot regeneration using acute gamma was in the range of 10 to .15.0Gy and for ion beam was between 3.5 to 4.OGv. Relative biological effectiveness for ion beam was found 3.75 higher than the acute gamma. The regenerated plantlets were planted in the greenhouse at MARDI, Cameron Highland for morphological screening. The highest frequency of flower colour mutation for acute gamma was 77.8% whilst for ion beam were between 42.3 to 58.3%.
    Matched MeSH terms: X-Rays
  17. Pramanik S, Hanif ASM, Pingguan-Murphy B, Abu Osman NA
    Materials (Basel), 2012 Dec 21;6(1):65-75.
    PMID: 28809294 DOI: 10.3390/ma6010065
    In this work, untreated bovine cortical bones (BCBs) were exposed to a range of heat treatments in order to determine at which temperature the apatite develops an optimum morphology comprising porous nano hydroxyapatite (nanoHAp) crystals. Rectangular specimens (10 mm × 10 mm × 3-5 mm) of BCB were prepared, being excised in normal to longitudinal and transverse directions. Specimens were sintered at up to 900 °C under ambient pressure in order to produce apatites by two steps sintering. The samples were characterized by thermogravimetric analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM) attached to an energy-dispersive X-ray spectroscopy detector. For the first time, morphology of the HAp particles was predicted by XRD, and it was verified by SEM. The results show that an equiaxed polycrystalline HAp particle with uniform porosity was produced at 900 °C. It indicates that a porous nanoHAp achieved by sintering at 900 °C can be an ideal candidate as an in situ scaffold for load-bearing tissue applications.
    Matched MeSH terms: X-Rays
  18. Barua PD, Muhammad Gowdh NF, Rahmat K, Ramli N, Ng WL, Chan WY, et al.
    PMID: 34360343 DOI: 10.3390/ijerph18158052
    COVID-19 and pneumonia detection using medical images is a topic of immense interest in medical and healthcare research. Various advanced medical imaging and machine learning techniques have been presented to detect these respiratory disorders accurately. In this work, we have proposed a novel COVID-19 detection system using an exemplar and hybrid fused deep feature generator with X-ray images. The proposed Exemplar COVID-19FclNet9 comprises three basic steps: exemplar deep feature generation, iterative feature selection and classification. The novelty of this work is the feature extraction using three pre-trained convolutional neural networks (CNNs) in the presented feature extraction phase. The common aspects of these pre-trained CNNs are that they have three fully connected layers, and these networks are AlexNet, VGG16 and VGG19. The fully connected layer of these networks is used to generate deep features using an exemplar structure, and a nine-feature generation method is obtained. The loss values of these feature extractors are computed, and the best three extractors are selected. The features of the top three fully connected features are merged. An iterative selector is used to select the most informative features. The chosen features are classified using a support vector machine (SVM) classifier. The proposed COVID-19FclNet9 applied nine deep feature extraction methods by using three deep networks together. The most appropriate deep feature generation model selection and iterative feature selection have been employed to utilise their advantages together. By using these techniques, the image classification ability of the used three deep networks has been improved. The presented model is developed using four X-ray image corpora (DB1, DB2, DB3 and DB4) with two, three and four classes. The proposed Exemplar COVID-19FclNet9 achieved a classification accuracy of 97.60%, 89.96%, 98.84% and 99.64% using the SVM classifier with 10-fold cross-validation for four datasets, respectively. Our developed Exemplar COVID-19FclNet9 model has achieved high classification accuracy for all four databases and may be deployed for clinical application.
    Matched MeSH terms: X-Rays
  19. George, J., Teo, S.C., Adan, M.
    Malays Orthop J, 2008;2(1):33-37.
    Aim: This study was designed to evaluate the use of ultrasound in diagnosis of infection and tumour of long bones. Methodology: Patients referred from the orthopaedic unit with doubt regarding long bone clinical and/or radiological signs which could be tumour or infection were enrolled in this study. Analysis of ultrasound characteristics included presence of pericortical fluid over normal cortex well away from the primary lesion, wavy contour sign (fluid tracking in and out muscle planes), subperiosteal fluid and soft tissue mass displacing adjacent muscle planes. Results: Fourteen out of 15 patients with confirmed osteomyelitis were diagnosed by ultrasound examination. Ultrasound as a diagnostic tool has a sensitivity of 93% and specificity of 100%. The most accurate indicator was pericortical fluid noted up to several centimetres from the long bone abnormality seen on plain x-rays. Conclusion: Ultrasound is a safe, fast, cost-effective imaging modality that can play an important role in diagnosis of osteomyelitis as it then serves as a tool for ultrasound guided aspiration.
    Matched MeSH terms: X-Rays
  20. Fathul Karim Sahrani, Zaharah Ibrahim, Madzlan Aziz, Adibah Yahya
    Corrosion caused by sulphate-reducing bacteria (SRB) isolated from seawater nearby to Pasir Gudang has been studied. The test coupon was a AISI 304 stainless steel. Potential and corrosion rate measurements were carried out in various types of culturing solutions, with SRB1, SRB2, combination of SRB1 & SRB2 and without SRBs inoculated (sterilized). From Tafel plots a higher corrosion rate has been found in medium inoculated with SRBs than that of the sterilized medium (control). When SRBs were present in the medium, the Tafel plot shifted towards more negative values (Ecorr was shifted to much less anodic values) and increase in current density compared to that of the sterilized medium (control). Localized corrosion was observed on the metal surface, and it was associated to the SRB activity. X-ray analysis (EDAX) showed that the corrosion product has higher content of sulphur for medium containing SRBs than that of the sterilized medium. X-Ray Diffraction analysis carried out on corrosion products which showed the presence of iron sulphide. This indicates the influence of the presence of SRB in corrosion process.
    Matched MeSH terms: X-Rays
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