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31.
Intensity modulated fiber vibrations sensing using Khazani Syed (KS) and Modified Quadratic Congruence Code (MQC) code for quasi distributed vibration measurement have been evaluated. The systems employed Spectral Direct (SD) Decoding for Spectral Amplitude Coding-Optical Code Division Multiple Access (SAC-OCDMA). SAC-OCDMA is adopted because of its enormous impact in dealing with Multiple Access Interference (MAI). The setup was carried out for three sensor points in three consecutive measurements. The performance of the sensing system with the KS and MQC codes were compared at the same weight and number of code sequence. It was observed that the applied vibration frequencies were obtained at the receivers and the signal employing MQC are received at slightly better power than KS code. However, KS code setup employed less number of components and therefore, reduce the cost and complexity of achieving quasi-distributed vibration sensing. 相似文献
32.
Abdul Ghani Zuleen Delina Fasya Ab Rashid Ahmad Hazri Shaari Khozirah Chik Zamri 《Applied biochemistry and biotechnology》2019,189(2):690-708
Applied Biochemistry and Biotechnology - The present studies are to evaluate the ability of PB to induce weight loss and urine metabolite profile of Piper betle L. (PB) leaf extracts using... 相似文献
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Mohd Sharizal Alias Sahbudin Shaari P. K. Choudhury Sufian Mitani 《Journal of Russian Laser Research》2009,30(4):368-375
A comprehensive study of the uniformity of 850 nm VCSEL epiwafer grown by the MOCVD technique is presented. By utilizing the
VCSEL planar structure, uniformity test is performed on-wafer directly, besides using the conventional photoluminescence technique.
The VCSEL quantum wells are found to exhibit a peak emission wavelength of 839.5 nm. Also, the grown epiwafer is observed
to exhibit a Fabry–Perot cavity resonance at 846.5 nm. Various VCSEL devices fabricated from the center to the edge of the
VCSEL epiwafer show a similar trend towards the light–current and output spectral characteristics. However, the device existing
near the epiwafer edge is observed to exhibit significantly different characteristics, which is attributed to the physical
conditions of the device near the edge, and also the limitations of the epitaxial growth. 相似文献
35.
Tan Pei Jean Khozirah Shaari Christian Paetz Intan Safinar Ismail Faridah Abas Nordin H. Lajis Viqar Uddin Ahmad 《Helvetica chimica acta》2009,92(10):1973-1982
Three new oleanane‐type triterpenoid saponins, 3‐O‐(α‐L ‐rhamnopyranosyl(1→2)‐β‐D ‐fucopyranosyl)‐28‐O‐{[α‐L ‐rhamnopyranosyl(1→2)] [β‐D ‐fucopyranosyl(1→6)]‐β‐D ‐glucopyranosyl} oleanolic acid ( 1 ), 3‐O‐[α‐L ‐rhamnopyranosyl(1→3)‐β‐D ‐fucopyranosyl]‐28‐O‐[α‐L ‐rhamnopyranosyl(1→4)‐β‐D ‐glucopyranosyl] oleanolic acid ( 2 ), and 3‐O‐{α‐L ‐rhamnopyranosyl(1→2)‐[3′,4′‐diacetoxy‐β‐D ‐fucopyranosyl]}‐28‐O‐[α‐L ‐rhamnopyranosyl(1→2)‐β‐D ‐glucopyranosyl] oleanolic acid ( 3 ) have been isolated from the stems of Xerospermum noronhianum. The structures of the saponins were determined as a series of bidesmosidic oleanane saponins based on spectral evidence. The anticholinesterase activity of the saponins 1 – 3 was also evaluated. 相似文献
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J. Ying Chyi Liew Zainal A. Talib W. Mahmood M. Yunus Zulkarnain Zainal Shaari A. Halim Mohd M. Moksin Wan Mohd Yusoff K. Pah Lim 《Central European Journal of Physics》2009,7(2):379-384
Thin films of copper selenide (CuSe) were physically deposited layer-by-layer up to 5 layers using thermal evaporation technique
onto a glass substrate. Various film properties, including the thickness, structure, morphology, surface roughness, average
grain size and electrical conductivity are studied and discussed. These properties are characterized by X-ray diffraction
(XRD), atomic force microscopy (AFM), ellipsometer and 4 point probe at room temperature. The dependence of electrical conductivity,
surface roughness, and average grain size on number of layers deposited is discussed.
相似文献
37.
Mohamad Shazeli Che Zain Muhamad Faris Osman Soo Yee Lee Khozirah Shaari 《Molecules (Basel, Switzerland)》2021,26(4)
Luteolin and apigenin derivatives present in oil palm (Elaeis guineensis) leaves (OPL) are reported to possess excellent antioxidant properties relating to numerous health benefits. To meet the global demand for flavonoids, OPL, which is plentifully generated as an agricultural by-product from oil palm plantations, can be further exploited as a new source of natural antioxidant compounds. However, to produce a standardized herbal preparation, validation of the quantification method for these compounds is required. Therefore, in this investigation, we developed and validated an improved and rapid analytical method, ultra-high-performance liquid chromatography equipped with ultraviolet/photodiode array (UHPLC-UV/PDA) for the quantification of 12 luteolin and apigenin derivatives, particularly focusing on flavonoid isomeric pairs: orientin/isoorientin and vitexin/isovitexin, present in various OPL extracts. Several validation parameters were assessed, resulting in the UHPLC-UV/PDA technique offering good specificity, linearity, accuracy, precision, and robustness, where the values were within acceptable limits. Subsequently, the validated method was employed to quantify luteolin and apigenin derivatives from OPL subjected to different drying treatments and extraction with various solvent systems, giving total luteolin (TLC) and apigenin content (TAC) in the range of 2.04–56.30 and 1.84–160.38 µg/mg extract, respectively. Additionally, partial least square (PLS) analysis disclosed the combination of freeze dry-aqueous methanol yielded OPL extracts with high TLC and TAC, which are strongly correlated with antioxidant activity. Therefore, we provide the first validation report of the UHPLC-UV/PDA method for quantification of luteolin and apigenin derivatives present in various OPL extracts, suggesting that this approach could be employed in standardized herbal preparations by adopting orientin, isoorientin, vitexin, and isovitexin as chemical markers. 相似文献
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Mohd Sharizal Alias Sahbudin Shaari Paul O. Leisher Kent D. Choquette 《Photonics and Nanostructures》2010,8(1):38-46
Single transverse mode control is achieved for multimode GaAs-based VCSEL by utilizing photonic crystal design and etched trench structure. Theoretical analysis is initially performed for photonic crystal design with various lattice constants and air holes diameter. The fabricated photonic crystal VCSEL with etched trench structure exhibits single mode output power of 0.7 mW, threshold current of 3.5 mA, slope efficiency of 0.10 W/A, and continuous single mode output spectrum throughout a wide operating current range. Comparison of typical oxide VCSEL, trench oxide VCSEL, and photonic crystal oxide VCSEL employing trench structure is presented. By combining photonic crystal and trench structure, single transverse mode operation of photonic crystal VCSEL can be much more strictly controlled. 相似文献
39.
We proposed a simple low-cost acrylic and metal-based Y-branch plastic optical fiber (POF) splitter which utilizes a low cost optical polymer glue NOA63 as the main waveguiding medium at the waveguide taper region. The device is composed of three sections: an input POF waveguide, a middle waveguide taper region and output POF waveguides. A desktop high speed CNC engraver is utilized to produce the mold inserts used for the optical devices. Short POF fibers are inserted into the engraved slots at the input and output ports. UV curable optical polymer glue NOA63 is injected into the waveguide taper region and cured. The assembling is completed when the top plate is positioned to enclose the device structure and connecting screws are secured. Both POF splitters have an average insertion loss of 7.8 dB, coupling ratio of 55: 45 and 57: 43 for the acrylic and metal-based splitters respectively. The devices have excess loss of 4.82 and 4.73 dB for the acrylic and metal-based splitters respectively. 相似文献
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N. Ali R. Ahmed A. Shaari I. Rahim M. Shah A. Hussain N. Ahmad S. M. Abbas 《Brazilian Journal of Physics》2014,44(6):733-738
We report the deposition and characterization of tin antimony sulfide thin films on a soda glass substrate by a thermal evaporation technique. The thin films were annealed in argon gas at 150, 175, and 300 °C inside glass ampoules. The structural and optical properties of the deposited and annealed films are investigated. X-ray diffraction (XRD) patterns show that the films are polycrystalline in structure. Photoconductivity plot revealed good response in the NIR and visible regions, while the films show no transmittance below 700 nm. The absorption coefficient was of the order of 106 cm?1. Optical band gaps were also evaluated and a decrease in band gap was observed due to annealing. Hot point probe technique was employed for type of conductivity. 相似文献