Displaying publications 1 - 20 of 34 in total

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  1. Ultrasound wave assisted removal of Ceftriaxone sodium in aqueous media with novel nano composite g-C3N4/MWCNT/Bi2WO6 based on CCD-RSM model
    Shi X, Karachi A, Hosseini M, Yazd MS, Kamyab H, Ebrahimi M, et al.
    Ultrason Sonochem, 2020 Nov;68:104460.
    PMID: 30712851 DOI: 10.1016/j.ultsonch.2019.01.018
    The aim of this study was ultrasound assisted removal of Ceftriaxone sodium (CS) based on CCD model. Using sonochemical synthesized Bi2WO6 implanted on graphitic carbon nitride/Multiwall carbon nanotube (g-C3N4/MWCNT/Bi2WO6). For this purpose g-C3N4/MWCNT/Bi2WO6 was synthesized and characterized using diverse approaches including XRD, FE-SEM, XPS, EDS, HRTEM, FT-IR. Then, the contribution of conventional variables including pH, CS concentration, adsorbent dosage and ultrasound contact time were studied by central composite design (CCD) under response surface methodology (RSM). ANOVA was employed to the variable factors, and the most desirable operational conditions mass provided. Drug adsorption yield of 98.85% obtained under these defined conditions. Through conducting five experiments, the proper prediction of the optimum point were examined. The respective results showed that RSD% was lower than 5% while the t-test confirmed the high quality of fitting. Langmuir isotherm equation fits the experimental data best and the removal followed pseudo-second order kinetics. The estimation of the experimentally obtained maximum adsorption capacities was 19.57 mg.g- of g-C3N4/MWCNT/Bi2WO6 for CS. Boundary layer diffusion explained the mechanism of removal via intraparticle diffusion.
    Matched MeSH terms: Tungsten Compounds
  2. Fulltext Photocatalysis and photoelectrochemical properties of tungsten trioxide nanostructured films
    Lai CW
    ScientificWorldJournal, 2014;2014:843587.
    PMID: 24782669 DOI: 10.1155/2014/843587
    Tungsten trioxide (WO₃) possesses a small band gap energy of 2.4-2.8 eV and is responsive to both ultraviolet and visible light irradiation including strong absorption of the solar spectrum and stable physicochemical properties. Thus, controlled growth of one-dimensional (1D) WO₃ nanotubular structures with desired length, diameter, and wall thickness has gained significant interest. In the present study, 1D WO₃ nanotubes were successfully synthesized via electrochemical anodization of tungsten (W) foil in an electrolyte composed of 1 M of sodium sulphate (Na₂SO₄) and ammonium fluoride (NH₄F). The influence of NH₄F content on the formation mechanism of anodic WO₃ nanotubular structure was investigated in detail. An optimization of fluoride ions played a critical role in controlling the chemical dissolution reaction in the interface of W/WO₃. Based on the results obtained, a minimum of 0.7 wt% of NH₄F content was required for completing transformation from W foil to WO₃ nanotubular structure with an average diameter of 85 nm and length of 250 nm within 15 min of anodization time. In this case, high aspect ratio of WO₃ nanotubular structure is preferred because larger active surface area will be provided for better photocatalytic and photoelectrochemical (PEC) reactions.
    Matched MeSH terms: Tungsten/chemistry*
  3. A DFT analyses for molecular structure, electronic state and spectroscopic property of a dithiolene tungsten carbonyl complex
    Arifin K, Daud WR, Kassim MB
    Spectrochim Acta A Mol Biomol Spectrosc, 2014 Apr 24;124:375-82.
    PMID: 24508875 DOI: 10.1016/j.saa.2013.12.107
    Bis(dithiolene) tungsten carbonyl complex, W(S2C2Ph2)2(CO)2 was successfully synthesized and the structure, frontier molecular orbital and optical properties of the complex were investigated theoretically using density functional theory calculations. The investigation started with a molecular structure construction, followed by an optimization of the structural geometry using generalized-gradient approximation (GGA) in a double numeric plus polarization (DNP) basis set at three different functional calculation approaches. Vibrational frequency analysis was used to confirm the optimized geometry of two possible conformations of [W(S2C2Ph2)2(CO)2], which showed distorted octahedral geometry. Electronic structure and optical characterization were done on the ground states. Metal to ligand and ligand to metal charge transfer were dominant in this system.
    Matched MeSH terms: Tungsten/chemistry*
  4. Synthesis, structure and theoretical investigation into a homoleptic tris(dithiolene) tungsten
    Arifin K, Minggu LJ, Daud WR, Yamin BM, Daik R, Kassim MB
    Spectrochim Acta A Mol Biomol Spectrosc, 2014;120:208-15.
    PMID: 24184623 DOI: 10.1016/j.saa.2013.09.069
    A new homoleptic dithiolene tungsten complex, tris-{1,2-bis(3,5-dimethoxyphenyl)-1,2-ethylenodithiolene-S,S'}tungsten, was successfully synthesized via a reaction of the thiophosphate ester and sodium tungstate. The thiophosphate ester was prepared from 3,5-dimethoxybenzaldehyde via benzoin condensation to produce the intermediate 1,2-bis-(3,5-dimethoxyphenyl)-2-hydroxy-ethanone compound, followed by a reaction of the intermediate with phosphorus pentasulfide. FTIR, UV-Vis spectroscopy, 1H NMR and 13C NMR and elemental analysis confirmed the product as tris{1,2-bis-(3,5-dimethoxyphenyl)-1,2-ethylenodithiolene-S,S'}tungsten with the molecular formula of C54H54O12S6W. Crystals of the product adopted a monoclinic system with space group of P2(1)/n, where a=12.756(2) Å, b=21.560(3) Å, c=24.980(4) Å and β=103.998(3)°. Three thioester ligands were attached to the tungsten as bidentate chelates to form a distorted octahedral geometry. Density functional theory calculations were performed to investigate the molecular properties in a generalized-gradient approximation framework system using Perdew-Burke-Ernzerhof functions and a double numeric plus polarization basis set. The HOMO was concentrated on the phenyl ligands, while the LUMO was found along the W(S2C2)3 rings. The theoretical optical properties showed a slight blue shift in several low dielectric solvents. The solvatochromism effect was insignificant for high polar solvents.
    Matched MeSH terms: Tungsten/chemistry*
  5. Fulltext 56 nm Wide-Band Tunable Q-Switched Erbium Doped Fiber Laser with Tungsten Ditelluride (WTe2) Saturable Absorber
    Ahmad H, Albaqawi HS, Yusoff N, Yi CW
    Sci Rep, 2020 Jun 17;10(1):9860.
    PMID: 32555280 DOI: 10.1038/s41598-020-66664-9
    A wide-band and tunable Q-switched erbium-doped fiber (EDF) laser operating at 1560.5 nm with a tungsten ditelluride (WTe2) saturable absorber (SA) is demonstrated. The semi-metallic nature of WTe2 as well as its small band gap and excellent nonlinear optical properties make it an excellent SA material. The laser cavity uses an 89.5 cm long EDF, pumped by a 980 nm laser diode as the linear gain while the WTe2 based SA generates the pulsed output. The WTe2 based SA has a modulation depth, non-saturable loss and saturation intensity of about 21.4%, 78.6%, and 0.35 kW/cm2 respectively. Stable pulses with a maximum repetition rate of 55.56 kHz, narrowest pulse width of 1.77 µs and highest pulse energy of 18.09 nJ are obtained at the maximum pump power of 244.5 mW. A 56 nm tuning range is obtained in the laser cavity, and the output is observed having a signal to noise ratio (SNR) of 48.5 dB. The demonstrated laser has potential for use in a large number of photonics applications.
    Matched MeSH terms: Tungsten
  6. Fulltext WS2: A New Window Layer Material for Solar Cell Application
    Bin Rafiq MKS, Amin N, Alharbi HF, Luqman M, Ayob A, Alharthi YS, et al.
    Sci Rep, 2020 Jan 21;10(1):771.
    PMID: 31964954 DOI: 10.1038/s41598-020-57596-5
    Radio frequency (RF) magnetron sputtering was used to deposit tungsten disulfide (WS2) thin films on top of soda lime glass substrates. The deposition power of RF magnetron sputtering varied at 50, 100, 150, 200, and 250 W to investigate the impact on film characteristics and determine the optimized conditions for suitable application in thin-film solar cells. Morphological, structural, and opto-electronic properties of as-grown films were investigated and analyzed for different deposition powers. All the WS2 films exhibited granular morphology and consisted of a rhombohedral phase with a strong preferential orientation toward the (101) crystal plane. Polycrystalline ultra-thin WS2 films with bandgap of 2.2 eV, carrier concentration of 1.01 × 1019 cm-3, and resistivity of 0.135 Ω-cm were successfully achieved at RF deposition power of 200 W. The optimized WS2 thin film was successfully incorporated as a window layer for the first time in CdTe/WS2 solar cell. Initial investigations revealed that the newly incorporated WS2 window layer in CdTe solar cell demonstrated photovoltaic conversion efficiency of 1.2% with Voc of 379 mV, Jsc of 11.5 mA/cm2, and FF of 27.1%. This study paves the way for WS2 thin film as a potential window layer to be used in thin-film solar cells.
    Matched MeSH terms: Tungsten
  7. Tribological behaviour of OA-capped WO3 nanoparticles as an additive to base oils
    Siti Fazlili Abdullah, Shahidan Radiman, Muhammad Azmi Abdul Hamid, Noor Baa’yah Ibrahim
    Sains Malaysiana, 2008;37:233-237.
    Oleic acid (OA) capped wolfram (VI) oxide, WO3 nanoparticles were chemically synthesized and characterized by means of Fourier Transform-Infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). The tribological properties of the capped WO3 nanoparticles as an additive in base oils were investigated using a four-ball machine. Results show that OA-capped WO3 nanoparticles are able to prevent water adsorption and capable of being dispersed stable in organic solvents which is base oils. The as-prepared capped WO3 nanoparticles have an average size of 15 nm. In addition, OA-capped WO3 nanoparticles as an additive in base oils perform good anti-wear (AW) and anti-friction (AF) properties owing to the formation of a boundary film.
    Matched MeSH terms: Tungsten
  8. Characterization of the feedstock properties of metal injection-molded WC-Co with palm stearin binder system
    Sri Yulis M. Amin, Norhamidi Muhamad, Khairur Rijal Jamaludin, Fayyaz A, Heng SY
    Sains Malaysiana, 2014;43:123-128.
    Feedstock preparation, as well as its characterization, is crucial in the production of highly sintered parts with minimal defect. The hard metal powder - particularly, cemented carbide (wc-co) used in this study was investigated both physically and thermally to determine its properties before the mixing and injection molding stage. Several analyses were conducted, such as scanning electron microscopy, energy dispersive X-ray diffraction, pycnometer density, critical powder volume percentage (cPvP), as well as thermal tests, such as thermogravimetric analysis and differential scanning calorimetry. On the basis of the CPVP value, the feedstock, consisting of wc-co powder, was mixed with 60% palm stearin and 40% polyethylene at an optimal powder loading, within 2 to 5% lower than the CPVP value. The CPVP spotted value was 65%. The feedstock optimal value at 61% showed good rheological properties (pseudoplastic behavior) with an n value lower than 1, considerably low activation energy and high moldability index. These preliminary properties of the feedstock serve as a benchmark in designing the schedule for the next whole steps (i.e. injection, debinding and sintering processes).
    Matched MeSH terms: Tungsten
  9. A novel ruthenium-tungsten bimetallic complex dye-sensitizer for photoelectrochemical cells application
    Khuzaimah Arifin, Wan Ramli Wan Daud, Mohammad B. Kassim
    Sains Malaysiana, 2014;43:95-101.
    A novel bimetallic double thiocyanate-bridged ruthenium and tungsten metal complex containing bipyridyl and dithiolene co-ligands was synthesized and the behavior of the complex as a dye-sensitizer for a photoelectrochemical (PEG) cell for a direct water splitting reaction was investigated. The ligands and metal complexes were characterized on the basis of elemental analysis as well as uv-Vis, Fourier transform infrared ( Pim) and nuclear magnetic resonance (11I and 13C NMR) spectroscopy. Cyclic voltammetry of the bimetallic complex showed multiple redox couples, in which half potentials E 112 at 0 .625 , 0.05 and 0.61 V were assigned as the formal redox processes of Ru(III)IRu(II) reduction, W(IV)IW(V) and W(V)IW(VI) oxidations, respectively. Photocurrent measurements were performed in homogeneous system and TiO2 was used as the photoanode for photocurrent measurements. Current density generated by the bimetallic complex was higher than that of N3 commercial dye which suggested that the bimetallic complex donated more electrons to the semiconductor.
    Matched MeSH terms: Tungsten
  10. Fulltext Tungsten-based material as promising new lead-free gamma radiation shielding material in nuclear medicine
    Jamal AbuAlRoos N, Azman MN, Baharul Amin NA, Zainon R
    Phys Med, 2020 Oct;78:48-57.
    PMID: 32942196 DOI: 10.1016/j.ejmp.2020.08.017
    PURPOSE: The main objective of this study was to evaluate the efficacy of tungsten carbide as new lead-free radiation shielding material in nuclear medicine by evaluating the attenuation properties.

    MATERIALS AND METHODS: The elemental composition of tungsten carbide was analysed using Field-Emission Scanning Electron Microscopy (FESEM) with energy dispersive X-ray (EDX). The purity of tungsten carbide was 99.9%, APS: 40-50 µm. Three discs of tungsten carbide was fabricated with thickness of 0.1 cm, 0.5 cm and 1.0 cm. Three lead discs with similar thickness were used to compare the attenuation properties with tungsten carbide discs. Energy calibration of gamma spectroscopy was performed by using 123I, 133Ba, 152Eu, and 137Cs. Gamma radiation from these sources were irradiated on both materials at energies ranging from 0.160 MeV to 0.779 MeV. The experimental attenuation coefficients of lead and tungsten carbide were compared with theoretical attenuation coefficients of both materials from NIST database. The half value layer and mean free path of both materials were also evaluated in this study.

    RESULTS: This study found that the peaks obtained from gamma spectroscopy have linear relationship with all energies used in this study. The relative differences between the measured and theoretical mass attenuation coefficients are within 0.19-5.11% for both materials. Tungsten carbide has low half value layer and mean free path compared to lead for all thickness at different energies.

    CONCLUSION: This study shows that tungsten carbide has high potential to replace lead as new lead-free radiation shielding material in nuclear medicine.

    Matched MeSH terms: Tungsten
  11. Fulltext Characterization of fusion welded joint: a review
    Nur Azida Che Lah, Aidy Ali, Napsiah Ismail
    Pertanika Journal of Science & Technology, 2009;17(2):-.
    MyJurnal
    Welding process is most widely used in joining components or structures in industry. Although welding is part of a larger category called metals joining, the weld itself still gives significant problems to engineers, researchers and manufacturers until today. Several widely used welding processes, such as the Metal Inert Gas (MIG), Tungsten Inert Gas (TIG), and Manual Metal Arc (MMA), were studied. In the present paper, the characterization of the macrostructure, microstructure, hardness and residual stress distribution are highlighted and discussed to achieve a better understanding of the welded quality which is crucial in determining the welded products.
    Matched MeSH terms: Tungsten
  12. Fulltext Selective formation of tungsten nanowires
    Bien DC, Saman RM, Badaruddin SA, Lee HW
    Nanoscale Res Lett, 2011;6(1):543.
    PMID: 21970543 DOI: 10.1186/1556-276X-6-543
    We report on a process for fabricating self-aligned tungsten (W) nanowires with polycrystalline silicon core. Tungsten nanowires as thin as 10 nm were formed by utilizing polysilicon sidewall transfer technology followed by selective deposition of tungsten by chemical vapor deposition (CVD) using WF6 as the precursor. With selective CVD, the process is self-limiting whereby the tungsten formation is confined to the polysilicon regions; hence, the nanowires are formed without the need for lithography or for additional processing. The fabricated tungsten nanowires were observed to be perfectly aligned, showing 100% selectivity to polysilicon and can be made to be electrically isolated from one another. The electrical conductivity of the nanowires was characterized to determine the effect of its physical dimensions. The conductivity for the tungsten nanowires were found to be 40% higher when compared to doped polysilicon nanowires of similar dimensions.
    Matched MeSH terms: Tungsten
  13. A current overview of the oxidative desulfurization of fuels utilizing heat and solar light: from materials design to catalysis for clean energy
    Lim XB, Ong WJ
    Nanoscale Horiz, 2021 May 21.
    PMID: 34018529 DOI: 10.1039/d1nh00127b
    The ceaseless increase of pollution cases due to the tremendous consumption of fossil fuels has steered the world towards an environmental crisis and necessitated urgency to curtail noxious sulfur oxide emissions. Since the world is moving toward green chemistry, a fuel desulfurization process driven by clean technology is of paramount significance in the field of environmental remediation. Among the novel desulfurization techniques, the oxidative desulfurization (ODS) process has been intensively studied and is highlighted as the rising star to effectuate sulfur-free fuels due to its mild reaction conditions and remarkable desulfurization performances in the past decade. This critical review emphasizes the latest advances in thermal catalytic ODS and photocatalytic ODS related to the design and synthesis routes of myriad materials. This encompasses the engineering of metal oxides, ionic liquids, deep eutectic solvents, polyoxometalates, metal-organic frameworks, metal-free materials and their hybrids in the customization of advantageous properties in terms of morphology, topography, composition and electronic states. The essential connection between catalyst characteristics and performances in ODS will be critically discussed along with corresponding reaction mechanisms to provide thorough insight for shaping future research directions. The impacts of oxidant type, solvent type, temperature and other pivotal factors on the effectiveness of ODS are outlined. Finally, a summary of confronted challenges and future outlooks in the journey to ODS application is presented.
    Matched MeSH terms: Tungsten Compounds
  14. Self-assembled heteropolyacid on nitrogen-enriched carbon nanofiber for vanadium flow batteries
    Etesami M, Abouzari-Lotf E, Sha'rani SS, Miyake M, Moozarm Nia P, Ripin A, et al.
    Nanoscale, 2018 Jul 13;10(27):13212-13222.
    PMID: 29971298 DOI: 10.1039/c8nr02450b
    A novel polyoxometalate-based electrode was developed by incorporating phosphotungstic acid (PWA) in nylon-6,6 nanofiber, followed by carbonization. The developed PWA-carbon nanofiber (PWA-CNF) showed the characteristics of the dual-scale porosity of micro- and mesoporous substrate with surface area of around 684 m2 g-1. The compound exhibited excellent stability in vanadium electrolyte and battery cycling. Evaluation of electrocatalytic properties toward V2+/V3+ and VO2+/VO2+ redox couples indicated promising advantages in electron transfer kinetics and increasing energy efficiency, particularly for the VO2+/VO2+ couple. Moreover, the developed electrode exhibited substantially improved energy efficiency (14% higher than that of pristine carbon felt) in the single cell vanadium redox flow battery. This outstanding performance was attributed to high surface area and abundant oxygen-containing linkages in the developed electrode.
    Matched MeSH terms: Tungsten Compounds
  15. Fulltext Investigation of Surface Plasmon Resonance (SPR) in MoS2- and WS2-Protected Titanium Side-Polished Optical Fiber as a Humidity Sensor
    Zakaria R, Zainuddin NAM, Leong TC, Rosli R, Rusdi MF, Harun SW, et al.
    Micromachines (Basel), 2019 Jul 11;10(7).
    PMID: 31336745 DOI: 10.3390/mi10070465
    In this paper, we report the effects of a side-polished fiber (SPF) coated with titanium (Ti) films in different thicknesses, namely 5 nm, 13 nm, and 36 nm, protected by a thin layer of transition metal dichalcogenides (TMDCs) such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2), which provide ultra-sensitive sensor-based surface plasmon resonance (SPR) covering from the visible to mid-infrared region. The SPF deposited with Ti exhibits strong evanescent field interaction with the MoS2 and WS2, and good optical absorption, hence resulting in high-sensitivity performance. Incremental increases in the thickness of the Ti layer contribute to the enhancement of the intensity of transmission with redshift and broad spectra. The findings show that the optimum thickness of Ti with 36 nm combined with MoS2 causes weak redshifts of the longitudinal localized surface plasmon resonance (LSPR) mode, while the same thickness of Ti with WS2 causes large blueshifts. The redshifts are possibly due to a reduced plasmon-coupling effect with the excitonic region of MoS2. The observed blueshifts of the LSPR peak position are possibly due to surface modification between WS2 and Ti. Changing the relative humidity from 58% to 88% only elicited a response in Ti/MoS2. Thus, MoS2 shows more sensitivity on 36-nm thickness of Ti compared with WS2. Therefore, the proposed fiber-optic sensor with integration of 2D materials is capable of measuring humidity in any environment.
    Matched MeSH terms: Tungsten
  16. Characterisation of micro-sized and nano-sized tungsten oxide-epoxy composites for radiation shielding of diagnostic X-rays
    Azman NZ, Siddiqui SA, Low IM
    Mater Sci Eng C Mater Biol Appl, 2013 Dec 1;33(8):4952-7.
    PMID: 24094209 DOI: 10.1016/j.msec.2013.08.023
    Characteristics of X-ray transmissions were investigated for epoxy composites filled with 2-10 vol% WO3 loadings using synchrotron X-ray absorption spectroscopy (XAS) at 10-40 keV. The results obtained were used to determine the equivalent X-ray energies for the operating X-ray tube voltages of mammography and radiology machines. The results confirmed the superior attenuation ability of nano-sized WO3-epoxy composites in the energy range of 10-25 keV when compared to their micro-sized counterparts. However, at higher synchrotron radiation energies (i.e., 30-40 keV), the X-ray transmission characteristics were similar with no apparent size effect for both nano-sized and micro-sized WO3-epoxy composites. The equivalent X-ray energies for the operating X-ray tube voltages of the mammography unit (25-49 kV) were in the range of 15-25 keV. Similarly, for a radiology unit operating at 40-60 kV, the equivalent energy range was 25-40 keV, and for operating voltages greater than 60 kV (i.e., 70-100 kV), the equivalent energy was in excess of 40 keV. The mechanical properties of epoxy composites increased initially with an increase in the filler loading but a further increase in the WO3 loading resulted in deterioration of flexural strength, modulus and hardness.
    Matched MeSH terms: Tungsten/chemistry*
  17. Fulltext InSitu Anodization of WO₃-Decorated TiO₂ Nanotube Arrays for Efficient Mercury Removal
    Lee WH, Lai CW, Hamid SBA
    Materials (Basel), 2015 Aug 28;8(9):5702-5714.
    PMID: 28793530 DOI: 10.3390/ma8095270
    WO₃-decorated TiO₂ nanotube arrays were successfully synthesized using an in situ anodization method in ethylene glycol electrolyte with dissolved H₂O₂ and ammonium fluoride in amounts ranging from 0 to 0.5 wt %. Anodization was carried out at a voltage of 40 V for a duration of 60 min. By using the less stable tungsten as the cathode material instead of the conventionally used platinum electrode, tungsten will form dissolved ions (W(6+)) in the electrolyte which will then move toward the titanium foil and form a coherent deposit on the titanium foil. The fluoride ion content was controlled to determine the optimum chemical dissolution rate of TiO₂ during anodization to produce a uniform nanotubular structure of TiO₂ film. Nanotube arrays were then characterized using FESEM, EDAX, XRD, as well as Raman spectroscopy. Based on the FESEM images obtained, nanotube arrays with an average pore diameter of up to 65 nm and a length of 1.8 µm were produced. The tungsten element in the samples was confirmed by EDAX results which showed varying tungsten content from 0.22 to 2.30 at%. XRD and Raman results showed the anatase phase of TiO₂ after calcination at 400 °C for 4 h in air atmosphere. The mercury removal efficiency of the nanotube arrays was investigated by photoirradiating samples dipped in mercury chloride solution with TUV (Tube ultraviolet) 96W UV-B Germicidal light. The nanotubes with the highest aspect ratio (15.9) and geometric surface area factor (92.0) exhibited the best mercury removal performance due to a larger active surface area, which enables more Hg(2+) to adsorb onto the catalyst surface to undergo reduction to Hg⁰. The incorporation of WO₃ species onto TiO₂ nanotubes also improved the mercury removal performance due to improved charge separation and decreased charge carrier recombination because of the charge transfer from the conduction band of TiO₂ to the conduction band of WO₃.
    Matched MeSH terms: Tungsten
  18. Fulltext Use of an Industrial Tungsten Carbide Drill in the Treatment of a Complex Fracture in a Patient with Severe Osteopetrosis: A Case Report
    Kunnasegaran R, Chan YH
    Malays Orthop J, 2017 Mar;11(1):64-67.
    PMID: 28435578 DOI: 10.5704/MOJ.1703.007
    The treatment of fractures in osteopetrosis can be complicated and difficult. We describe the use of an industrial grade tungsten carbide drill bit in the treatment of one of these complex fractures. An industrial grade tungsten carbide drill bit was used to fashion a medullary canal in the surgical treatment of a left peri-implant fracture of the neck of femur in a patient with osteopetrosis. The patient was successfully treated with a hemiarthroplasty with good functional outcomes. A tungsten carbide drill bit serves as an effective and safe option in the treatment of osteopetrotic femoral neck fractures.
    Matched MeSH terms: Tungsten Compounds
  19. Fulltext Perbandingan dos glandular purata payudara berdasarkan kombinasi anod/penuras tungsten/rhodium dan tungsten/argentum pada mamografi digital
    Chelliah, Kanaga Kumari, Lumin, Felecia
    Jurnal Sains Kesihatan Malaysia, 2012;10(1):53-56.
    MyJurnal
    Mamografi adalah cara paling efektif untuk mengesan keabnormalan payudara di kalangan wanita. Namun, mamografi dipercayai boleh menyebabkan karsinogenesis aruhan sinaran. Justeru pengukuran dos adalah penting untuk menganggar risiko dan mengawal kualiti imej. Kajian ini dijalankan untuk membandingkan dos glandular purata (AGD) yang diperolehi fantom payudara berdasarkan dua kombinasi anod/penuras yang berbeza iaitu tungsten/rhodium (W/Rh) dan tungsten/argentum (W/Ag). Fantom payudara CIRS 012A didedahkan pada projeksi kraniokaudal (CC) menggunakan sistem mamografi digital Hologic Selenia. Kerma udara kemasukan permukaan (ESAK) diukur menggunakan dosimeter pendar cahaya terma (TLD). AGD diperolehi daripada pengiraan asas ESAK dengan faktor penukaran berdasarkan formula Euref. Ujian t tak bersandar menunjukkan perbezaan bererti dalam purata AGD yang diperolehi. Purata AGD W/Rh adalah lebih tinggi berbanding purata AGD W/Ag (p = 0.002, 95% CI: 0.22, 0.53). Kesimpulannya, penggunaan W/Ag menyumbang kepada pengurangan dos semasa pemeriksaan mamografi.
    Matched MeSH terms: Tungsten
  20. Fulltext Biodiesel synthesis catalyzed by transition metal oxides: ferric-manganese doped tungstated/molybdena nanoparticle catalyst
    Alhassan FH, Rashid U, Taufiq-Yap YH
    J Oleo Sci, 2015;64(1):91-9.
    PMID: 25492234 DOI: 10.5650/jos.ess14161
    The solid acid Ferric-manganese doped tungstated/molybdena nananoparticle catalyst was prepared via impregnation reaction followed by calcination at 600°C for 3 h. The characterization was done using X-ray diffraction (XRD), Raman spectroscopy, thermal gravimetric analysis (TGA), temperature programmed desorption of NH3 (TPD-NH3), X-ray fluorescence (XRF), Transmission electron microscope (TEM) and Brunner-Emmett-Teller surface area measurement (BET). Moreover, dependence of biodiesel yield on the reaction variables such as the reaction temperature, catalyst loading, as well as molar ratio of methanol/oil and reusability were also appraised. The catalyst was reused six times without any loss in activity with maximum yield of 92.3% ±1.12 achieved in the optimized conditions of reaction temperature of 200°C; stirring speed of 600 rpm, 1:25 molar ratio of oil to alcohol, 6 % w/w catalyst loading as well as 8 h as time of the reaction. The fuel properties of WCOME's were evaluated, including the density, kinematic viscosity, pour point, cloud point and flash point whereas all properties were compared with the limits in the ASTM D6751 standard.
    Matched MeSH terms: Tungsten Compounds/chemistry*
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