Displaying publications 81 - 100 of 275 in total

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  1. Shakinah Salleh, Affrida Abu Hassan, Shuhaimi Shamsudin, Yahya Awang, Ab. Kahar Sandrang, Abdullah, Thohirah Lee
    MyJurnal
    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
  2. Khairiah Yazid @ Khalid, Roslan Yahya, Nadira Kamarudini, Mohd. Zaid Abdullah, Mohd Ashhar Khalid, Abdul Aziz Mohamed
    MyJurnal
    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
  3. Zaini Hamzah, Nurul Latiffah Abd Rani, Ahmad Saat
    MyJurnal
    Measurement of major cation such as Na+, K+, and Ca2+ in water are normally carried out using
    AAS, ICP-OES or flame photometry. In this study, an attempt was made to measure these cations
    using Energy Dispersive X-ray Fluorescent Spectrometry (EDXRF). Hot spring s water was taken from varies hot spring in Selangor and divided into two portions that is filtered and unfiltered. 5 mL of water samples were pipette into a special liquid cups (sample holders) which has a thin mylar film underneath. The MiniPal4 XRF instrument was used in this study. The resolution for the instrument use is 145 keV with energy resolution at 5.9 keV. The spectrum of cations were analysed by using MiniPal/MiniMate software to determine the cations concentration. For K+ and Ca2+, Al-thin filter was used and default filter was used for Na+. The concentration of Na+ obtained for filtered and unfiltered samples were ranged from 38.00 to 66.05 and 43.26 to 76.95 ppm. Meanwhile, concentrations of K+ for filtered and unfiltered samples were ranged from 2.42 to 8.07 and 6.18 to 29.28 ppm. Concentrations of Ca2+ for filtered and unfiltered samples were ranged from 2.59 to 10.94 and 3.18 to 12.99 ppm.
    Matched MeSH terms: X-Rays
  4. Tan, Shiuan Lee, Mohd Fadhli Khamis, Albajalan, Osama Bahaa, Norehan Mokhtar
    MyJurnal
    Cephalometric analyses using computer software have more advantages than manual analyses. However, the software should be evaluated for the accuracy and reproducibility before it can be used. The aims of the present study were: 1) to compare the differences in accuracy and precision between utilizing scanned images and soft copy images with the software 2) to assess the reproducibility of software and manual cephalometric analyses. Fifteen cephalograms were selected randomly from the Record Unit, Hospital Universiti Sains Malaysia. All films had 10 fiducial points marked and were scanned at 75 dots per inch (dpi) and 300 dpi. Manual and digital measurements were compared to obtain magnification factors. Seven digital x-ray images of a caliper were taken. The mean differences were measured between the fixed caliper measurement and digital measurements. Subsequently, 37 cephalograms were traced manually and digitally with Computer-Assisted Simulation System for Orthognathic Surgery (CASSOS) software to assess its accuracy and reproducibility after applying the obtained magnification factor. Steiner analysis was utilized and T tests were used to evaluate the mean difference. P
    Matched MeSH terms: X-Rays
  5. Ng, Boon Lim, Lockman, Zainovia
    MyJurnal
    Texture evolution of NiO formed during oxidation of polycrystalline single oriented (100) Ni-Cr was investigated. This foil was also termed rolling assisted biaxially textured substrate (RABiTS). X-ray diffractograms of oxidized Ni-Cr RABiTS foil showed the existence of mostly (200) NiO indicating (100)-type NiO formed exclusively on (100) singly oriented Ni-Cr grains. Epitaxial relationship between the two layers is observed. However the dual-in-plane texture was recorded.
    The in-plane texture was assessed by conducting phi scan and plotting series of pole figures measured at (111) NiO peak. The mechanism of the oxides formation was proposed to take into account the formation of (100)-type NiO. Cross section morphology of the oxidised foils reveals two oxidation layers; fast growing external layer consisting of the (100)-type NiO and an internal layer consisted of mostly Cr2O3 and maybe NiCr2O4. The thickness of NiO was ~ 10Pm. Cr2O3 formed as needle-like oxides embedded in a matrix of Ni foil. Inward diffusion of oxygen is believed to have caused this to happen. The external NiO layer was consisted of duplex microstructure characterised by columnar layer growing vertical on the surface of the metal and a few micron thick of equiaxed NiO. Delamination of the outer NiO layer often occurred at the columnarequiaxed interface which could be cured by CeO2 deposition on the foil prior to the oxidation process. CeO2 was deposited by conversion immersion using Ce(NO3)3.6H2O solution. (200) NiO formed on this coated sample as well.
    Matched MeSH terms: X-Rays
  6. Prastomo, Niki, Lockman, Zainovia, Ahmad Fauzi Mohd Noor, Ahmad Nuruddin, Matsuda, Atsunori
    MyJurnal
    Tetragonal Y2O3 stabilized Zirconia (t-Y-ZrO2) powders were doped with Nb2O5 to seek a possibility if electronics doping would enhance the electronics conductivity of the insulating oxide. In this work Y2O3 was added as a stabilizer to produce tetragonal ZrO2 whereas Nb2O5 was added for the electronic doping. Several compositions of powders were prepared by thermal decomposition method and were post annealed at different temperatures. Precursor solutions were prepared from the mixture of zirconyl nitrate, yttrium nitrate and niobium tartarate as well as TEA (triethanolamine). The mixed solution were evaporated, pyrolysed and calcined to produce nanosized powders. The phase formation of the as-made powders was investigated by x-ray diffractometer. The additions of 7% Y2O3 were found to stabilize the tetragonal phase of zirconia.
    The addition of Nb2O5 did not alter the stability of the tetragonal phase but it was found that the conductivity of the material has changed. The band gap as measured by the UV-Visible Spectrometer gave a value in the range of 2.97 to 5.01 eV. XRD was also used to deduce the crystallite size (by using Scherer’s equation) and transmission electron microcopy was used to view the particle sizes and shapes. The Nb doped t-Y-ZrO2 prepared in this work was to be nanosized crystal with size ranges from 7 nm to 15 nm.
    Matched MeSH terms: X-Rays
  7. Meor Yusoff, M.S., Masliana Muslimin, Latifah Amin
    MyJurnal
    Tin slag was collected from a slag dump in the Penang Island and was analysed for its elemental composition using microfocus XRF with a 300ȝm x-ray spot diameter. The tin slag sample was analysed direct without any sample treatment and analysis was conduct on four different spots. The result gives different elemental composition on these different spots. Among the elements analysed are Al2O3, SiO2, SnO2, CaO, TiO2, Nd2O3, MnO, Fe2O3, TaO, W2O3, As2O3, ThO2, U3O8, ZrO2 and Nb2O5. Elemental mapping was also done to show the distribution of these elements in the sample.
    Matched MeSH terms: X-Rays
  8. Salih, A.M., Wan Md. Zin Wan Yunus, Khairul Zaman Mohd Dahlan, Mohd Hilmi Mahmood, Mansor Ahmad
    MyJurnal
    Synthesis of palm oil based-urethane acrylate (POBUA) resins was carried out by acrylation of epoxidizedpalm oil (EPOP) using acrylic acid in the presence of a catalyst and followed by isocyanation to obtainthe POBUA. Using the monomer as a diluent in the formulation, 4% of photoinitiator and incorporationof organoclay (1-5% wt), nanocomposites were obtained upon UV irradiation. The X-ray DiffractoryXRD study revealed that the nanocomposites obtained were of the exfoliation type. The presence ofthe clay improved the hardness and did not affect the thermal stability. Similarly, it increased the glasstransition temperature Tg but reduced the modulus as the clay content was increased. The improvementof the tensile strength was only obtained when the clay concentration was 5 phr.
    Matched MeSH terms: X-Rays
  9. Bradley, D.A., Ramli, A.T., Hashim, S., Wagiran, H., Webb, M., Jeynes, C.
    ASM Science Journal, 2010;4(1):15-21.
    MyJurnal
    This research was focused on the thermoluminescence (TL) response of commercially produced single-mode telecommunication optical fibre manufactured by INOCORP (Canada). The fibres were either in the form of pure silica (SiO2) or as SiO2 doped with Ge or Al at concentrations appropriate for total internal reflection, as required for telecommunication purposes. Each of these INOCORP fibres had a core diameter of 125 ± 0.1 μm. It was noted that dopant concentration was not included among the data provided in the accompanying product data sheet. A particularly important parameter for obtaining the highest TL yield in this study was the dopant concentration of the SiO2 fibre. The dopants tended to diffuse during the production of the optical fibre. To obtain this parameter, proton induced X-ray emission (PIXE) analysis was utilised. PIXE while having limited depth resolution could unambiguously identify elements and analyse trace elements with a detection limit approaching μg g–1. For Al-doped fibres, dopant concentrations in the range of 0.98 – 2.93 mol% had been estimated, the equivalent range for Ge-doped fibres was 0.53 – 0.71 mol%. A linear dose response was observed following 2.5 MeV proton irradiation for Ge- and Al-doped fibres for up to 7 min exposure.
    Matched MeSH terms: X-Rays
  10. Sabar Bauk, Abd. Aziz Tajuddin
    MyJurnal
    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
  11. 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
  12. Mohd Fudzi L, Zainal Z, Lim HN, Chang SK, Holi AM, Sarif Mohd Ali M
    Materials (Basel), 2018 Apr 29;11(5).
    PMID: 29710822 DOI: 10.3390/ma11050704
    Despite its large band gap, ZnO has wide applicability in many fields ranging from gas sensors to solar cells. ZnO was chosen over other materials because of its large exciton binding energy (60 meV) and its stability to high-energy radiation. In this study, ZnO nanorods were deposited on ITO glass via a simple dip coating followed by a hydrothermal growth. The morphological, structural and compositional characteristics of the prepared films were analyzed using X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), and ultraviolet-visible spectroscopy (UV-Vis). Photoelectrochemical conversion efficiencies were evaluated via photocurrent measurements under calibrated halogen lamp illumination. Thin film prepared at 120 °C for 4 h of hydrothermal treatment possessed a hexagonal wurtzite structure with the crystallite size of 19.2 nm. The average diameter of the ZnO nanorods was 37.7 nm and the thickness was found to be 2680.2 nm. According to FESEM images, as the hydrothermal growth temperature increases, the nanorod diameter become smaller. Moreover, the thickness of the nanorods increase with the growth time. Therefore, the sample prepared at 120 °C for 4 h displayed an impressive photoresponse by achieving high current density of 0.1944 mA/cm².
    Matched MeSH terms: X-Rays
  13. Ong, S.F., Nik Azlan, N.M.
    Medicine & Health, 2017;12(1):90-93.
    MyJurnal
    We report a case of a giant bullous emphysema misdiagnosed as a pneumothorax. A 18-year-old chronic smoker presented with right sided chest pain and dyspnoea. Initial respiratory rate was 35 /min, blood pressure was 136/90 mmHg, heart rate 80/min and SpO2 was 98% on room air. Clinical examination revealed reduced right air entry and left trachea deviation. Chest X-ray helped to arrive at a diagnosis of pneumothorax. Needle aspiration was then performed followed by a chest tube thoracostomy because of no improvement. Massive amount of blood was drained and patient deteriorated further. CT thorax revealed a right haemopneumothorax with multiple bullaes. Patient was rushed to OT for emergency thoracotomy for stapling of the ruptured bullae. Giant bullous emphysema can mimic pneumothorax and physician must be vigilant if draining a suspected pneumothorax.
    Keywords: emphysema, haemopneumothorax, thoracostomy, thorax
    Matched MeSH terms: X-Rays
  14. Ooi, Z.V., Saif, A.A., Poopalan, P.
    MyJurnal
    Sol-gel barium titanate (BaTiO3) and erbium doped barium titanate (Er-BaTiO3) were deposited on SiO2/Si substrates. The phase and crystallinity of the thin films were identified using x-ray diffractometer (XRD). The effect of Er dopant into BaTiO3 thin film on its grain size and surface roughness was studied using atomic force microscope (AFM) in tapping mode. XRD patterns revealed that the films were crystallized with perovskite structure. At the same time, it was shown that introducing Er dopant into BaTiO3 thin film caused the dominant peak to shift towards higher angle. AFM micrographs indicated that the films had well distributed grains, dense and crack-free surface. In general, substitution of Er dopant into Ba-site reduced the grain sizes and roughness parameter of the BaTiO3 which was attributed to the smaller ionic radius of Er.
    Matched MeSH terms: X-Rays
  15. Doris M, Aziz F, Alhummiany H, Bawazeer T, Alsenany N, Mahmoud A, et al.
    Nanoscale Res Lett, 2017 Dec;12(1):67.
    PMID: 28116608 DOI: 10.1186/s11671-017-1851-0
    In this study, low-bandgap polymer poly{[4,4-bis(2-ethylhexyl)-cyclopenta-(2,1-b;3,4-b')dithiophen]-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl} (PCPDTBT) nanostructures have been synthesized via a hard nanoporous alumina template of centrifugal process. Centrifuge has been used to infiltrate the PCPDTBT solution into the nanoporous alumina by varying the rotational speeds. The rotational speed of centrifuge is directly proportional to the infiltration force that penetrates into the nanochannels of the template. By varying the rotational speed of centrifuge, different types of PCPDTBT nanostructures are procured. Infiltration force created during the centrifugal process has been found a dominant factor in tuning the morphological, optical, and structural properties of PCPDTBT nanostructures. The field emission scanning electron microscopy (FESEM) images proved the formation of nanotubes and nanowires. The energy-dispersive X-ray spectroscope (EDX) analysis showed that the nanostructures were composed of PCPDTBT with complete dissolution of the template.
    Matched MeSH terms: X-Rays
  16. Chakraborty S, Goswami S, Quah CK, Pakhira B
    R Soc Open Sci, 2018 Jun;5(6):180149.
    PMID: 30110468 DOI: 10.1098/rsos.180149
    Single-crystal X-ray structures of dimeric quinoxaline aldehyde (QA), quinoxaline dihydrazone (DHQ) and HQNM (Goswami S et al. 2013 Tetrahedron Lett.54, 5075-5077. (doi:10.1016/j.tetlet.2013.07.051); Goswami S et al. 2014 RSC Adv.4, 20 922-20 926. (doi:10.1039/C4RA00594E); Goswami S et al. 2014 New J. Chem.38, 6230-6235. (doi:10.1039/C4NJ01498G)) are reported along with the theoretical study. Among them, QA is not acting as an active probe, but DHQ and HQNM are serving as selective and sensitive probe for the Fe3+ cation and the Ni2+ cation, respectively. DHQ can also detect the Fe3+ in commercial fruit juices (grape and pomegranate).
    Matched MeSH terms: X-Rays
  17. Rahman MA, Ahamed E, Faruque MRI, Islam MT
    Sci Rep, 2018 Oct 08;8(1):14948.
    PMID: 30297730 DOI: 10.1038/s41598-018-33295-0
    Various techniques are commonly used to produce nano-crystalline NiAl2O4 materials; however, their practical applications in the microwave region remain very limited. In this work, flexible substrates for metamaterials containing two different concentrations of NiAl2O4 (labelled Ni36 and Ni42) have been synthesised using a sol-gel method. The formation of spinel structures in the synthesised materials is confirmed, and their crystalline sizes are determined using scanning electron microscopy, X-ray diffraction, and energy dispersive X-ray techniques. The dielectric properties, conductivities, loss tangents, and other parameters of the NiAl2O4-based substrates are analysed to evaluate their applicability as dielectric materials for the microwave frequency range. The obtained results show that the fabricated Ni36 and Ni42 nickel aluminates possess dielectric constants of 4.94 and 4.97 and loss tangents of 0.01 and 0.007, respectively; in addition, they exhibit high flexibility and light weight, which make them suitable for applications as metamaterial substrates. The synthesised structures are also validated experimentally using a commercially available electromagnetic simulator; as a result, double negative behaviour of the flexible metamaterials has been observed. Furthermore, it is found that the prepared NiAl2O4 substrates can be used in the S-, C-, and X-bands of the microwave frequency region.
    Matched MeSH terms: X-Rays
  18. Kayode JS, Yusup Y, Nawawi MNM, Ariffin KS, Kalil AE, Tagwa MG
    Data Brief, 2018 Oct;20:1525-1531.
    PMID: 30258956 DOI: 10.1016/j.dib.2018.09.014
    Energy Dispersive X-ray Analysis, EDX mapping, Scanning Electron Microscope, SEM, together with X-ray Fluorescence Analysis, XRF, was carried out to extract the needed data from some metamorphic rock samples in part of the Nigerian Southwestern Precambrian Basement Complex, NSPBC. The foremost aim is to obtain the detail subsurface geological structures of the rocks within the area and to enhanced understanding of the processes and the types of metamorphic evolution in the area. The techniques involved qualitative and quantitative data analysis of the major, minor and radioactive elements present in the samples of rocks analyzed. The data helped to experimentally evaluate the rocks microstructures, and to also explore the development of magmatic and metamorphic mechanisms for the recognition of textual associations in the area. Applications of the EDX, SEM, and XRF data analysis are effortlessly done to determine the varied mixtures of Si, Al, Ca, Fe, K, Mg, and Na, in the presence of O existing in the rocks samples.The data helped in the classification and perceptive of these rocks and it was considered as a necessary tool in the knowledge of the metamorphism and origin of the Basement Complex rocks through measurement of the intensity of the emitted X-ray and its characteristics.
    Matched MeSH terms: X-Rays
  19. Sandu AV, Vasilache V, Sandu IG, Sieliechi JM, Kouame IK, Matasaru PD, et al.
    Materials (Basel), 2019 Nov 21;12(23).
    PMID: 31766445 DOI: 10.3390/ma12233836
    The paper presents the results of ample investigations performed on industrial and traditional ceramics of fired clay used in processes of water potabilization in the last stage of filtration, after that of active charcoal. Using the data obtained through the scanning electron microscope coupled with energy dispersive X-ray analysis (SEM-EDX) and pH analyses, on the basis of the atomic composition and free concentration of hydronium ions, the normal caustic (Si/Al) and summative [(Si+Ti+FeIII+Cl)/(Al+Ca+Mg+Na+K)] modules were assessed, which were correlated with the free acidity and, respectively, the capacity of absorption and ionic exchange of the Fe3+ and Al3+ ions. The study allowed the selection, on the basis of the caustic module, of the ceramics with high capacity for ionic exchange.
    Matched MeSH terms: X-Rays
  20. Liao X, Zhang Y, Wang J, Kang J, Zhang J, Wang J, et al.
    Materials (Basel), 2019 Nov 09;12(22).
    PMID: 31717524 DOI: 10.3390/ma12223698
    The tunability of semi-conductivity in SrTiO3 single crystal substrates has been realized by a simple encapsulated annealing method under argon atmosphere. This high temperature annealing-induced property changes are characterized by the transmission spectra, scanning electron microscopy (SEM) and synchrotron-based X-ray absorption (XAS). We find the optical property is strongly influenced by the annealing time (with significant decrease of transmittance). A sub gap absorption at ~427 nm is detected which is attributed to the introduction of oxygen vacancy. Interestingly, in the SEM images, annealing-induced regularly rectangle nano-patterns are directly observed which is contributed to the conducting filaments. The XAS of O K-edge spectra shows the changes of electronic structure by annealing. Very importantly, resistance switching response is displayed in the annealed SrTiO3 single crystal. This suggests a possible simplified route to tune the conductivity of SrTiO3 and further develop novel resistance switching materials.
    Matched MeSH terms: X-Rays
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