Yazar "Celik, Gultekin" seçeneğine göre listele

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    The calculation of transition probabilities between individual lines for atomic lithium
    (PERGAMON-ELSEVIER SCIENCE LTD, 2007) Celik, Gultekin
    The atomic transition probabilities for individual and multiplet lines of lithium atom are obtained using weakest bound electron potential model theory (WBEPMT) and exact quantum defect theory. The results obtained using two different methods agree very well with the accepted values taken from NIST, MCHF results and Opacity Project values. These methods require substantially less computational time than well-known theoretical methods, thereby permitting the study of 108 transitions. (c) 2006 Elsevier Ltd. All rights reserved.
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    Comparison of transition probabilities calculated using different parameters on WBEPM theory for some p-d and d-p transitions in excited atomic nitrogen
    (JOHN WILEY & SONS INC, 2007) Celik, Gultekin; Akin, Erhan; Kilic, Hamdi Sukur
    The transition probabilities between individual and multiplet lines for some quartet terms of excited p-d and d-p transition arrays of nitrogen atom have been calculated using the weakest bound electron potential model (WBEPM) theory. For determination relevant parameters, we employed both numerical Coulomb approximation (NCA) method and numerical nonrelativistic Hartree-Fock (NRHF) wave functions for expectation values of radii. The necessary energy values have been taken from experimental energy data in the literature. The expectation values of radii obtained using the two different methods have been employed in the calculation of transition probabilities of all transition arrays. The results obtained have been compared with either each other or NIST data. Good agreement with accepted values taken from NIST has been observed for related excited transitions. (c) 2006 Wiley Periodicals, Inc.
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    Electric quadrupole transition probabilities and line strengths of Ti11+
    (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2014) Gokce, Yasin; Celik, Gultekin; Yildiz, Murat
    Electric quadrupole transition probabilities and line strengths have been calculated using the weakest bound electron potential model for sodium-like titanium, considering many transition arrays. We employed numerical Coulomb approximation and non-relativistic Hartree-Fock wavefunctions for the expectation values of radii in determination of parameters of the model. The necessary energy values have been taken from experimental data in the literature. The calculated electric quadrupole line strengths have been compared with available data in the literature and good agreement has been obtained. Moreover, some electric quadrupole transition probability and line strength values not existing in the literature for some highly excited levels have been obtained using this method. (C) 2014 Elsevier Inc. All rights reserved.
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    Electric quadrupole transition probabilities for atomic lithium
    (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2014) Celik, Gultekin; Gokce, Yasin; Yildiz, Murat
    Electric quadrupole transition probabilities for atomic lithium have been calculated using the weakest bound electron potential model theory (WBEPMT). We have employed numerical non-relativistic Hartree-Fock wavefunctions for expectation values of radii and the necessary energy values have been taken from the compilation at NIST. The results obtained with the present method agree very well with the Coulomb approximation results given by Caves (1975). Moreover, electric quadrupole transition probability values not existing in the literature for some highly excited levels have been obtained using the WBEPMT. (c) 2014 Elsevier Inc. All rights reserved.
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    Electric quadrupole transition probabilities for singly ionized magnesium
    (PERGAMON-ELSEVIER SCIENCE LTD, 2012) Celik, Gultekin; Dogan, Duygu; Ates, Sule; Taser, Mehmet
    Electric quadrupole transition probabilities for Mg II have been calculated within the weakest bound electron potential model (WBEPM) theory using experimental energy levels and theoretical expectation values of orbital radii corresponding to those energy levels under the assumption of the LS coupling scheme. In this work, the WBEPM theory has been applied to forbidden transitions for the first time. The present results are consistent with earlier theoretical calculations. Some of these results are reported for the first time. (C) 2012 Elsevier Ltd. All rights reserved.
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    Influence of Boron Substitution on the Crystal and Electronic Properties of LiCrO2 Battery Cathode
    (SPRINGER, 2017) Ozkendir, Osman Murat; Ates, Sule; Celik, Gultekin; Klysubun, Wantana
    Boron-substituted LiCrO2 battery cathode material samples were investigated by X-ray-based techniques to probe the influence of boron on their crystal and electronic structure properties. Studies were carried on a series of Li-ion battery cathode materials with the general formula LiCr1-x B (x) O-2. Up to 10 pct boron substitution amounts, light boron atoms were determined to sit in Cr coordinations. However, for more substitutions (> 10 pct), higher electronegativity of boron was determined to govern the crystal structure by obtaining isolated boron-centered domains and built Li2BO4 structures. Electronic structure studies and further crystal structure analysis were carried by X-ray absorption fine structure technique. In the studied samples, increasing boron concentration in the samples (i.e., > 10 pct substitution) were determined to cause a decrease in oxygen bond distances as a result of boron sitting in some chromium locations. As a result of this study, 10 pct boron substitution was determined as a threshold to protect the LiCrO2 crystal structure. (C) The Minerals, Metals & Materials Society and ASM International 2017
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    Oscillator strengths and lifetimes for Cu I
    (CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS, 2015) Celik, Gultekin; Ates, Sule; Erol, Elmas
    Electric dipole oscillator strengths and lifetimes for Cu I have been calculated within the weakest bound electron potential model theory and the quantum defect orbital theory under the assumption of the LS coupling scheme. In the calculations, many transition arrays including both multiplet and fine-structure transitions are considered. The present results are consistent with earlier theoretical calculations and experimental measurements. Some of these results are reported for the first time.
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    Oscillator strengths and transition probabilities for singly ionized terbium
    (CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS, 2014) Ates, Sule; Gokce, Yasin; Celik, Gultekin; Yildiz, Murat
    Electric dipole transition probabilities and oscillator strengths for singly ionized terbium (Tb II) have been calculated with the weakest bound electron potential model (WBEPM) theory using experimental energy levels and theoretical expectation values of orbital radii corresponding to those energy levels under the assumption of the Jj coupling scheme. The transition probabilities and the oscillator strengths calculated have been compared with available data in the literature. A good agreement has been obtained. In this work, the WBEPM theory has been applied to heavy atoms, such as Tb II, for the first time.
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    Transition probabilities, oscillator strengths and lifetimes for singly ionized magnesium
    (PERGAMON-ELSEVIER SCIENCE LTD, 2011) Celik, Gultekin; Ates, Sule; Ozarslan, Selma; Taser, Mehmet
    The electric dipole transition probabilities, oscillator strengths and lifetimes have been calculated using the weakest bound electron potential model theory (WBEPMT) for singly ionized magnesium. In the calculations both multiplet and fine structure transitions are studied. We have employed both the numerical Coulomb approximation (NCA) method and numerical non-relativistic Hartree-Fock (NRHF) wave functions for expectation values of radii. The calculated oscillator strengths and lifetimes have been compared with MCHF results given by Fischer et al. (2006). A good agreement has been obtained with the MCHF results. Moreover, some new transition probabilities, oscillator strengths and lifetime values, not existing in the data bases for highly excited levels in singly ionized magnesium, have been obtained using this method. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
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    Transition probabilities, oscillator strengths and radiative lifetimes for Zn II
    (PERGAMON-ELSEVIER SCIENCE LTD, 2013) Celik, Gultekin; Erol, Elmas; Taser, Mehmet
    The electric dipole transition probabilities, the oscillator strengths and the lifetimes of excited levels have been calculated using the weakest bound electron potential model theory (WBEPMT) and the quantum defect orbital theory (QDOT) for singly ionized Zinc. In the calculations, the many of transition arrays including both multiplet and fine-structure transitions are considered. We have employed numerical Coulomb approximation (NCA) wave functions and numerical non-relativistic Hartree-Fock (NRHF) wave functions for expectation values of radii in determination of parameters. The present results are consistent with the available theoretical and experimental results. Some of these results are reported for the first time. (C) 2013 Elsevier Ltd. All rights reserved.