Matematik Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/413
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Article Citation - WoS: 49Citation - Scopus: 51Multidetermination of Thiamine Hcl and Pyridoxine Hcl in Their Mixture Using Continuous Daubechies and Biorthogonal Wavelet Analysis(Elsevier Science Bv, 2003) Baleanu, D; Dinç, EA new graphical method based on the one-dimensional wavelet transform (WT) was proposed and tested on mixture of thiamine hydrochloride (THI) and pyridoxine hydrochloride (PYR) in the presence of strongly overlapping signals. We selected from the data of the UV-VIS absorption spectra a signal consisting of 1150 points corresponding to the concentration range 8-32 mg ml(-1) for each vitamin and we subjected it to Daubechies8 (DAUB8) and Biorthogonal6.8 (BIOR6.8) wavelet transforms. Since the peaks of the transformed signals were bigger than original ones a zero crossing method was applied to obtain the calibration graphs. In addition, the validity of Beer-Lambert law was assumed for the transformed signals. An appropriate scale setting was choosing to obtain an alternative calibration for each method. MATLAB 6.5 software was used for one-dimensional wavelet analysis and the basic concepts about wavelet method were given. The obtained results were successfully compared among each other as well as with those obtained by other literature methods. The method developed in this paper is rapid, easy to apply, not expensive and it is suitable for analyzing of the overlapping signals of compounds in their mixtures without any chemical pre-treatment. (C) 2002 Elsevier Science B.V. All rights reserved.Article Citation - WoS: 12Citation - Scopus: 11Dualisation of the Symmetric Space Sigma Model With Couplings(Elsevier Science Bv, 2005) Dereli, T; Yilmaz, NTThe first-order formulation of the G/K symmetric space sigma model of the scalar cosets of the supergravity theories is discussed when there is coupling of (m - 1)-form matter fields. The Lie superalgebra which enables the dualized coset formulation is constructed for a general scalar coset G/K with matter coupling where G is a non-compact real form of a semi-simple Lie group and K is its maximal compact subgroup. (C) 2004 Elsevier B.V. All rights reserved.Article Citation - WoS: 72Citation - Scopus: 81An Application of Derivative and Continuous Wavelet Transforms To the Overlapping Ratio Spectra for the Quantitative Multiresolution of a Ternary Mixture of Paracetamol, Acetylsalicylic Acid and Caffeine in Tablets(Elsevier Science Bv, 2005) Özdemir, A; Baleanu, D; Dinç, EQuantitative multi resolution of tablets and ternary mixtures of paracetamol (PAR), acetylsalicylic acid (ASP) and caffeine (CAF) having strongly overlapping spectra was accomplished by two graphical transform methods as ratio spectra first derivative-zero crossing and ratio spectra-continuous wavelet transform-zero crossing (ratio spectra CWT-zero crossing) methods. In this study, ratio spectra derivative-zero crossing and ratio spectra CWT-zero crossing methods are based on the use of transformed signals of the ratio spectra and their calibration graphs were obtained by measuring the dA/dlambda and CWT amplitudes of the ratio spectra corresponding to zero crossing points. For the comparison purpose. PLS calibration method was applied to predict the content of the same mixtures containing the subject active Compounds. The obtained calibrations were tested by using the synthetic mixtures and standard addition technique and they applied to the simultaneous determination of PAR, ASP and CAF in commercial pharmaceutical preparation. The obtained results were statistically compared with each other as well as those obtained by HPLC method and they showed good agreement. (C) 2004 Published by Elsevier B.V.Article Citation - WoS: 51Citation - Scopus: 56Comparative Study of the Continuous Wavelet Transform, Derivative and Partial Least Squares Methods Applied To the Overlapping Spectra for the Simultaneous Quantitative Resolution of Ascorbic Acid and Acetylsalicylic Acid in Effervescent Tablets(Elsevier Science Bv, 2005) Ozdemir, A; Baleanu, D; Dinç, EThe simultaneous spectrophotometric determination of ascorbic acid (AA) and acetylsalicylic acid (ASA) in effervescent tablets in the presence of the overlapping spectra was accomplished by the continuous wavelet transform (CWT), derivative spectrophotometry (DS) and partial least squares (PLS) approaches without using any chemical pre-treatment. CWT and DS calibration equations for AA and ASA were obtained by measuring the CWT and DS amplitudes corresponding to zero-crossing points of spectra obtained by plotting continuous wavelet coefficients and first-derivative absorbance values versus the wavelengths, respectively. The PLS calibration was constructed by using the concentration set and its full absorbance data consisting of 850 points from 220 to 305 urn in the range of 210-310 nun. These three methods were tested by analyzing the synthetic mixtures of the above drugs and they were applied to the real samples containing two commercial pharmaceutical preparations of subjected drugs. A comparative study was carried out by using the experimental results obtained from three analytical methodologies and precise and accurate results were obtained. (c) 2004 Published by Elsevier B.V.Article Citation - WoS: 2Citation - Scopus: 2An Implicit Decoupling for the Dilatons and the Axions of the Heterotic String(Elsevier Science Bv, 2007) Yilmaz, Nejat T.A set of consistency conditions is derived for the massless sector of the D-dimensional E-8 x E-8 heterotic string. Under the solvable Lie algebra gauge these conditions are further formulated explicitly in terms of the dilatons and the axions. It is then shown that these consistency conditions which are satisfied by the solution space give way to an implicit decoupling between the coset scalar sector namely the dilatons and the axions and the gauge fields of the theory. (c) 2007 Elsevier B.V. All rights reserved.Article Citation - WoS: 34Citation - Scopus: 37Perron's Theorem for Linear Impulsive Differential Equations With Distributed Delay(Elsevier Science Bv, 2006) Alzabut, J.; Zafer, A.; Akhmet, M. U.In this paper it is shown that under a Perron condition trivial solution of linear impulsive differential equation with distributed delay is uniformly asymptotically stable. (c) 2005 Elsevier B.V. All rights reserved.Article Citation - WoS: 78Citation - Scopus: 83Convergence of General Beams Into Gaussian-Intensity Profiles After Propagation in Turbulent Atmosphere(Elsevier Science Bv, 2006) Baykal, Yahya; Sermutlu, Emre; Eyyuboglu, Halil T.It is shown that a general shaped laser beam will eventually approach a Gaussian average intensity profile after propagation in turbulent atmosphere. In our formulation, source field at the exit plane of the laser is taken as the product of arbitrary functions of source transverse coordinates with Gaussian exponential modulations. Following the expansion of the arbitrary functions in terms of Hermite polynomials, the average receiver intensity expression is derived using the extended Huygens-Fresnel principle and the conditions for the intensity profile to assume a Gaussian shape are stated. The results are illustrated by simulating various source field distributions. (c) 2006 Elsevier B.V. All rights reserved.Article Citation - WoS: 4Citation - Scopus: 4Symmetric Space Σ-Model Dynamics: Internal Metric Formalism(Elsevier Science Bv, 2006) Yilmaz, Nejat T.For the symmetric space sigma model in the internal metric formalism we explicitly construct the Lagrangian in terms of the axions and the dilatons of the solvable Lie algebra gauge and then we exactly derive the axion-dilaton field equations. (c) 2006 Published by Elsevier B.V.