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717 results for “SPECT”
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Research ArticleOpen accessEvery word in the titleAn Initio Theoretical Study for the Electronic Spectra of β-ThioxoketonesRita S. Elias, Bahjat A. Saeed, Dhiyaa K. MuslemProblem statement: β-thioxoketones exist as equilibrium mixtures of the tautomeric enol and enethiol forms which interconvert very rapidly by intramolecular chelate proton transfer. Accordingly their electronic spectra in the u.v.-visible region exhibit absorption bands arising from transitions within the electronic systems involved in these tautomers. Approach: The structures of several β-thioxoketones were geometrically optimized using B3LYP/cc-pVTZ, B3LYP/6-311++G (2d,p), PM2/6-311++G(2d,p) and … …American Journal of Applied Sciences, Vol. 9, Issue 1 · 24 Nov 2011 · 7,854 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleFrontal Arabic Fricative Consonants Characteristics among Primary School Children: Spectral Density Function ApproachNurul Ashikin Abdul-Kadir, Rubita SudirmanProblem statement: Arabic speech recognition system is un-developed until today. By using people of non-Arab nationality, the set of frontal fricative of Arabic consonants are study as the earlier step to develop the recognition system for Malaysian. As most of the developed Arabic speech recognition system for Malaysian are rarely found. Approach: The characteristic of each of the phonemes were … …Journal of Computer Science, Vol. 7, Issue 10 · 9 Aug 2011 · 7,175 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleDesign and Cost Performance of Decoding Technique for Hybrid Subcarrier Spectral Amplitude Coding-Optical Code Division Multiple Access SystemR.K.Z. Sahbudin, M.K. Abdullah, M. Mokhtar et al.Problem statement: A hybrid technique combining subcarrier multiplexed and Spectral Amplitude Coding-Optical Code Division Multiple Access (SAC-OCDMA) deploying the Khazani-Syed code was proposed. It was proposed as a mean of increasing the maximum number of simultaneous active users by increasing the subcarrier and/or the SAC-OCDMA code word. Multiple Access Interference (MAI) is the most dominant cause of performance degradation in … …Journal of Computer Science, Vol. 7, Issue 10 · 4 Aug 2011 · 6,875 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleFabrication of X-Ray Optics for a Portable Total Reflection X-Ray Fluorescence Spectrometer Using Electrolytic in Process Dressing Grinding and Magnetorheological FinishingShinsuke Kunimura, Hiroshi Kasuga, Yosuke Hachisu, Hitoshi OhmoriProblem statement: A portable X-ray elemental analyzer (total reflection X-ray fluorescence spectrometer) has been developed since 2006 and this spectrometer made it possible to perform ultra trace elemental determination. The intensity of scattered X-rays that become background noise in a spectrum is reduced with the improvement in surface accuracy of an X-ray reflector used in the portable spectrometer and therefore … …Current Research in Nanotechnology, Vol. 1, Issue 2 · 21 Jun 2011 · 7,293 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleA New Approach in Individual Tree Counting of Nyatoh (Palaquium spp.) Using an Airborne SpectroradiometerKamaruzaman JusoffProblem statement: In Malaysia inadequate data are available to make decisions regarding the sustainable management of Nyatoh (Palaquium spp.). Factual data and estimation of Nyatoh in the lowland dipterocarp forest resources are still lacking or, if available, are not complete, reliable or up to date. The collection and compilation of information and updating of existing data in near real time … …American Journal of Applied Sciences, Vol. 7, Issue 4 · 30 Apr 2010 · 7,955 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleAsymptotic Properties of Spectral Estimates of Second-Order with Missed ObservationsG. S. Mokaddis, M. A. Ghazal, A. E. El-DesokeyProblem statement: As a complement of the periodogram study the asymptotic properties of the spectral density using data window for stationary stochastic process are investigated. Some statistical properties of covariance estimation function with missing observations are studied. Approach: The asymptotic normality was discussed. A numerical example was discussed by using computer programming. Results: The study of time series with missed … …Journal of Mathematics and Statistics, Vol. 6, Issue 1 · 31 Mar 2010 · 7,496 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleMetabolic Fingerprinting of Three Malaysian Ginger (Zingiber officinale Roscoe) Using Gas Chromatography-Mass SpectromertryH.J. Mahdi, R. Andayani, IshakProblem statement: There is a chemical variation among different ginger cultivars detected by previous studies including the volatile and non-volatile oleo-resins. In this study we try to determine whether these variations are related to a genetic factor rather than environmental or intrinsic factors. Approach: A comprehensive metabolic fingerprinting from the leaves of three micro-propagated ginger cultivars Bukit Tinggi, Tanjung Sepat … …American Journal of Applied Sciences, Vol. 7, Issue 1 · 31 Jan 2010 · 7,387 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleOn the Pseudo-Spectral Method of Solving Linear Ordinary Differential EquationsB. S. OgundareProblem statement: Not all differential equations can be solved analytically, to overcome this problem, there is need to search for an accurate approximate solution. Approach: The objective of this study was to find an accurate approximation technique (scheme) for solving linear differential equations. By exploiting the Trigonometric identity property of the Chebyshev polynomial, we developed a numerical scheme referred to … …Journal of Mathematics and Statistics, Vol. 5, Issue 2 · 30 Jun 2009 · 7,222 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleRefractive Index and Fourier Transform Infrared Spectra of Virgin Coconut Oil and Virgin Olive OilW. Mahmood Mat Yunus, Yap Wing Fen, Lim Mei YeeThis study presents the refractive index and FTIR spectra of virgin coconut oil and virgin olive oil that have been measured in the wavelength range from 491.0-667.8 nm. The measurement of refractive index was carried out using a minimum deviation method while the IR transmission ranging from 600-4000 cm-1 was measured using FTIR spectrometer respectively. The measurements were done at … …American Journal of Applied Sciences, Vol. 6, Issue 2 · 28 Feb 2009 · 13,159 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleDetermination of Ibuprofen and Paracetamol in Binary Mixture Using Chemometric-Assisted Spectrophotometric MethodsWafaa S. HassanThree methods are presented for simultaneous determination of ibuprofen and paracetamol without previous separation. The first method depends on first derivative UV spectrophotometry, with zero-crossing measurement. The first derivative amplitudes at 230 and 290 nm were selected for the assay of ibuprofen and paracetamol, respectively. The second method depends on first derivative of the ratio-spectra by measurements of the amplitudes … …American Journal of Applied Sciences, Vol. 5, Issue 8 · 31 Aug 2008 · 8,199 accessesView PDFCite