Elektronik ve Haberleşme Mühendisliği Bölümü Yayın Koleksiyonu
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Browsing Elektronik ve Haberleşme Mühendisliği Bölümü Yayın Koleksiyonu by Author "120207"
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Article Citation Count: Böyükata, M., Özdoğan, C., Güvenç, Z.B. (2007). An investigation of hydrogen bonded neutral B4Hn (n=1-11) and anionic B4H11(-1) clusters: Density functional study. Journal of Molecular Structure-Theochem, 805(1-3), 91-100. http://dx.doi.org/10.1016/j.theochem.2006.10.015An investigation of hydrogen bonded neutral B4Hn (n=1-11) and anionic B4H11(-1) clusters: Density functional study(Elsevier Science, 2007) Böyükata, Mustafa; Özdoğan, Cem; Güvenç, Ziya B.; 120207In this study, detailed analysis of the structural stability of hydrogen bonded four-atom boron clusters within the framework of density functional theory (DFT) is presented. Effects of the number of hydrogen atoms on the structural stability of 134, binding energy of the clusters, and also on the boron-hydrogen binding energy are investigated. Attention is also paid to the determination of energetically the most stable geometries of B4Hn (n = 1-11) boron hydrides, and to their isomers. The lower-lying electronic states of the B4Hn structures are investigated. In addition natural electron configurations of the most stable clusters and charge transfer between the atoms in the cluster are also analyzed. Furthermore, the stability of anionic form of B4H11(-1) cluster is examinedArticle Citation Count: Böyükata, M., Koçyiğit, Y., Güvenç, Z.B. (2008). Determination of chemisorption probabilities of hydrogen molecules on a nickel surface by Artificial Neural Network. Croatica Chemica Acta, 81(2), 305-310.Determination of chemisorption probabilities of hydrogen molecules on a nickel surface by Artificial Neural Network(Croatian Chemical Soc, 2008) Böyükata, Mustafa; Koçyiğit, Yücel; Güvenç, Büşra; 120207; 53469Dissociative chemisorption probabilities for H(2)(v, j) + Ni(100) collision systems have been estimated by using Artificial Neural Network (ANN). For training, previously determined probability values via molecular dynamics simulations have been used. Performance of the ANN, for predicting any quantities in the molecule-surface interaction, has been investigated. Effects of the surface sites and the rovibrational states of the molecule on the process are analyzed. The results are in good agreement with the related previous studiesArticle Citation Count: Böüyükata, M., Özdoğn, C., Güvenç, Z.B. (2008). Effects of hydrogen hosting on cage structures of boron clusters: density functional study of B(m)H(n) (m=5-10 and n <= m) complexes. Physica Scripta, 77(2). http://dx.doi.org/10.1088/0031-8949/77/02/025602Effects of hydrogen hosting on cage structures of boron clusters: density functional study of B(m)H(n) (m=5-10 and n <= m) complexes(IOP Publishing Ltd, 2008) Böyükata, Mustafa; Özdoğan, Cem; Güvenç, Ziya B.; 120207The structural stability of hydrogen bonded boron microclusters has been studied by using the density functional theory. Effects of the increasing number of hydrogen atoms on the cage geometries of B(5)-B(10) clusters, and the distortion of the cage configurations of the boranes are assessed. The possible stable structures of B(m)H(n)(m = 5-10 and n <= m) boron hydrides, their binding energies, HOMO-LUMO energy gaps and the total atomic charges of the B(m) in the complexes are determined. For the series of B(5)H(n), B(7)H(n), and B(9)H(n) major structural changes are observedArticle Citation Count: Böyükata, M., Güvenç, Z.B. (2006). Effects of molecular rovibrational states and surface topologies for molecule-surface interaction: Chemisorption dynamics of D(2) collision with rigid Ni surfaces. Brazilian Journal of Physics, 36(3A), 725-729Effects of molecular rovibrational states and surface topologies for molecule-surface interaction: Chemisorption dynamics of D(2) collision with rigid Ni surfaces(Springer, 2006) Böyükata, Mustafa; Güvenç, Ziya B.; 120207A quasiclassical and micro-canonical molecular dynamic simulation techniques have been applied for D(2)(v,j) + Ni-surface collision systems. Dissociative adsorptions of a D(2) molecule on the rigid low index (100), (110) and (111), surfaces of the nickel are investigated to understand the effects of the different surfaces, impact sites and the initial rovibrational states of the molecule on molecule-surface collisions. Interactions between the molecule and the Ni surfaces are mimicked by a LEPS potential. Dissociative chemisorption probabilities of the D(2)(v,j) Molecule ( for the vibrational (v) = 0 and rotational (j) = 0, 1, 3, 10, and for the v = 1,j = 0 states on different impact sites of the surfaces) are presented for the translation energies between 0.001 and 1.0 eV. The probabilities obtained at each collision site have unique behavior for the colliding molecule which is moving along the surface normal direction. It has been observed that at the low collision energies the indirect processes (steering effects) enhance the reactivity on the surfaces. The results are compared to the related studies in the literature.Article Citation Count: Böyükata, M., Koçyiğit, Y., Güvenç, Z.B. (2006). Estimation of cross sections for molecule-cluster interactions by using artificial neural networks. Brazilian Journal of Physics, 36(3A), 730-735Estimation of cross sections for molecule-cluster interactions by using artificial neural networks(Springer, 2006) Böyükata, Mustafa; Koçyiğit, Yücel; Güvenç, Büşra; 120207; 53469The cross sections Of D(2) (v,j) + Ni(n) (T), n = 19 and 20, collision systems have been estimated by using Artificial Neural Networks (ANNs). For training, previously determined cross section values via molecular dynamics simulation have been used. The performance of the ANNs for predicting any quantities in molecule-cluster interaction has been investigated. Effects of the temperature of the clusters and the rovibrational states of the molecule are analyzed. The results are in good agreement with previous studies.Article Citation Count: Kurt, E., Böyükata, M., Güvenç, Z.B. (2006). Lyapunov exponent as an indicator of phase transition in melting Pd-13 clusters. Physica Scripta, 74(3), 353-361. http://dx.doi.org/10.1088/0031-8949/74/3/009Lyapunov exponent as an indicator of phase transition in melting Pd-13 clusters(Royal Swedish Acad Sciences, 2006) Kurt, Erol; Böyükata, Mustafa; Güvenç, Büşra; 13410; 120207In this study, the chaotic behaviour of Pd13 clusters is investigated in a wide total energy range. To identify interactions between atoms, the embedded atom potential is used in the computer simulation. Various analyses including power spectra, maximal Lyapunov exponents (lambda) and rms bond-length fluctuations (delta) are carried out to identify the characteristics of the system. As a result of these analyses, it is observed that Lyapunov spectra can clearly indicate the co-existence region for Pd-13 clusters and exponents have fixed values above a certain total energy value of the system. In addition, while the fast Fourier transforms give the existence of diffusive motion above the transitional region, the correlation dimension values exhibit a smooth character relevant to the total energies of the system.Article Citation Count: Böyükata, M., Güvenç Z.B. (2006). MD study of energetics, melting and isomerization of aluminum microclusters. Brazilian Journal of Physics , 36(3A), 720-724.MD study of energetics, melting and isomerization of aluminum microclusters(Springer, 2006) Böyükata, Mustafa; Güvenç, Ziya B.; 120207Voter and Chen version of an Embedded Atom Model has been applied to study the locally stable structures, energies, melting, isomerization and growth patterns of small aluminum clusters, Al(n), in the size range of n = 2 - 13. Using molecular dynamics and thermal quenching simulations, the global minima and the other locally stable structures have been distinguished from those stationary structures that correspond to saddle points of the potential energy surface. A large number (10000) of independent initial configurations generated at high temperatures has been used to obtain the stable isomers, and the probabilities of sampling different basins of attractions, for each size of the clusters. Their energy spectra have been determined and melting, and isomerization dynamics are investigated.
