Mete E.,Balkesir University |
Dansman M.F.,Middle East Technical University
Journal of Physical Chemistry C | Year: 2015
Here we present a density functional theory study of pentacene ultrathin films on flat and vicinal [(455)] Au(111) surfaces. We have performed crystal and electronic structure calculations by using PBE and optB86b-vdW functionals and investigated the effects of long-range van der Waals interactions for different coverages starting from a single isolated molecule up to 4 monolayers of coverage. For an isolated molecule both functionals yield the hollow site as the most stable one with the bridge-60 site being very close in energy in the case of optB86b-vdW. Binding strength of an isolated pentacene on the step edge was found to be much larger than that on the terrace sites. Different experimentally reported monolayer structures were compared and the (6 × 3) unit cell was found to be energetically more stable than the (2 × 2 7) and (2 × 31) ones. For one monolayer films while dispersion corrected calculations favored flat pentacene molecules on terraces, standard (PBE) calculations either found tilted and flat configurations to be energetically similar (on the flat (111) surface) or favored the tilted configuration (on the (455) surface). PDOS calculations performed with the optB86b-vdW functional showed larger dispersion of molecular orbitals over the Au states for the (455) surface when compared with the flat (111) surface, indicating an enhanced charge carrier transport at the pentacene-gold interface in favor of the vicinal surface. Starting with the second monolayer, both functionals favored tilted configurations for both surfaces. Our results underline the importance of the dispersion corrections for the loosely bound systems like pentacene on gold and the role played by step edges in determining the multilayer film structure and charge transfer at the organic molecule-metal interface. © 2015 American Chemical Society.
Sonmez S.,Adyaman University |
Sak S.,Balkesir University |
Karaytug S.,Mersin University
Marine Biodiversity | Year: 2015
In the present study, we contribute to the diversity of marine meiofauna of Turkey by describing both sexes of Schizopera karanovici sp. nov., which were collected from the intertidal zone of Alata beach, Turkey. The new species is closely related to S. lagrecai Pesce 1988, S. minuta Noodt 1955, and S. variseta Bozic, 1964, but can easily be differentiated from its congeners by the width/length ratio and setal organisation of the caudal rami and P5. © 2014, Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg.
Coban C.,Balkesir University |
Colakoglu K.,Gazi University |
Ciftci Y.O.,Gazi University
Journal of Physics and Chemistry of Solids | Year: 2012
The structural and lattice dynamical properties of TmX (X=As, P) compounds were investigated using normconserving pseudopotentials within the generalized gradient approximation correction (GGA) of Perdew-Burke-Ernzerhof (PBE) in the framework of density functional theory (DFT). The structural parameters (a 0, B, B′, E coh) were determined through total energy and interatomic force minimization and the overall agreement was found to be good. The pressure dependence of the ratios of normalized lattice parameters a/a 0, normalized volume V/V 0, bulk modulus, elastic constants, Zener anisotropy factor, Poissons ratio, Youngs modulus, shear modulus, and the brittleness were presented and discussed. The thermodynamical properties such as thermal expansion, heat capacity, Debye temperature, and Grüneisen parameter were calculated employing the quasi-harmonic Debye model at different temperatures (0-1000 K) and pressures (0-30 GPa). The phonon dispersion curves and corresponding density of states (DOS) of TmX (X=As, P) were also obtained, and the salient results were interpreted. © 2012 Elsevier Ltd.
Aydin S.,Balkesir University
Computer Assisted Language Learning | Year: 2015
This study presents a review of the literature that examines WebQuests as tools for second-language acquisition and foreign language-learning processes to guide teachers in their teaching activities and researchers in further research on the issue. The study first introduces the theoretical background behind WebQuest use in the mentioned processes. It then reviews studies that examine WebQuests as tools used in second-language acquisition and foreign language-learning processes. The study concludes that WebQuest use improves interaction, communication, critical thinking, knowledge application, social skills, scaffolded learning, higher order thinking skills and problem-solving skills. Moreover, WebQuests help learners to acquire and learn linguistic and extra-linguistic knowledge in a secure atmosphere in the processes of second-language acquisition and foreign language learning. Second, the results of the reviewed studies show that WebQuests have positive effects on reading skills and vocabulary knowledge. The paper ends with practical recommendations for teachers and researchers. © 2015 Taylor & Francis
Saritas S.,Balkesir University
Turkish Online Journal of Educational Technology | Year: 2015
No matter who we are or where we live, our lives revolve around food, which is much more than a merely sustenance. As a part of the human culture, food carries complex significance and symbolic meanings. Turkish people attribute great value to food and its usage specifically tied to rites of passage of human life. Traditions, especially the ones practiced during rites of passage, such as birth, circumcisions, weddings and funerals, have always been accompanied by food in Turkish culture. Since food celebrates and symbolizes human progress in life in the culture, it also surrounds by aspects of belief, custom, magic, ritual and religion and has always been used in ceremonial context during such rites. Even though that context may be different depending on the religious, economic and social nuances of the various Turkish regions, like wheat, meat and bread, certain kinds of food play key roles during Turkish rites, generally upholding traditions. This paper highlights the place of food in the rites of passage in Turkish culture. © The Turkish Online Journal of Educational Technology.