Now showing items 1-20 of 27

    • Adsorption and dissociation of hydrogen molecules on bare and functionalized carbon nanotubes 

      Dag, S.; Ozturk, Y.; Çıracı, Salim; Yildirim, T. (American Physical Society, 2005)
      Interaction between hydrogen molecules and bare as well as functionalized single-wall carbon nanotubes (SWNT) is investigated using first-principles plane wave method. It is found that the binding energy of the H2 physisorbed ...
    • Effects of hydrogen adsorption on single-wall carbon nanotubes: metallic hydrogen decoration 

      Gülseren, O.; Yildirim, T.; Çıracı, Salim (American Physical Society, 2002)
      We show that the electronic and atomic structure of carbon nanotubes undergo dramatic changes with hydrogen chemisorption from first principle calculations. Upon uniform exohydrogenation at half coverage, the cross sections ...
    • Electronic structure of the contact between carbon nanotube and metal electrodes 

      Dag, S.; Gülseren, O.; Çıracı, Salim; Yildirim, T. (American Institute of Physics, 2003)
      Our first-principles study of the contact between a semiconducting single-walled carbon nanotube ~s-SWNT! and metal electrodes shows that the electronic structure and potential depend strongly on the type of metal. The ...
    • Exohydrogenated single-wall carbon nanotubes 

      Yildirim, T.; Gülseren, O.; Çıracı, Salim (American Physical Society, 2001)
      An extensive first-principles study of fully exohydrogenated zigzag (n,0) and armchair (n,n) single-wall carbon nanotubes (CnHn), polyhedral molecules including cubane, dodecahedrane, and C60H60 points to crucial differences ...
    • First-principles investigation of structural and electronic properties of solid cubane and its doped derivatives 

      Yildirim, T.; Çıracı, Salim; Kılıç, Ç.; Buldum, A. (American Physical Society, 2000)
      The electronic and structural properties of molecular and solid cubane have been studied by first-principles, self-consistent field total energy calculations. Calculated molecular properties such as equilibrium geometry ...
    • A First-principles Study of the Structure and Dynamics of C8H8, Si8H8, and Ge8H8 Molecules 

      Kiliç, Ç.; Yildirim, T.; Mehrez, H.; Çıracı, Salim (American Chemical Society, 2000)
      We present a first-principles study to elucidate the nature of the bonding, stability, energetics, and dynamics of individual X8H8 molecules (X = C, Si, Ge). The results obtained from both "local basis" and "pseudopotential" ...
    • Formation of quantum structures on a single nanotube by modulating hydrogen adsorption 

      Gülseren, O.; Yildirim, T.; Çıracı, Salim (American Physical Society, 2003)
      Using first-principles density functional calculations we showed that quantum structures can be generated on a single carbon nanotube by modulating the adsorption of hydrogen atoms. The band gap of the hydrogen-free zone ...
    • Functionalization of carbon-based nanostructures with light transition-metal atoms for hydrogen storage 

      Durgun, Engin; Çıracı, Salim; Yildirim, T. (American Physical Society, 2008)
      In a recent letter, the unusual hydrogen storage capacity of Ti decorated carbon nanotubes has been revealed. The present paper extends this study further to investigate the hydrogen uptake by light transition-metal atoms ...
    • Half-metallic properties of atomic chains of carbon-transition-metal compounds 

      Dag, S.; Tongay, S.; Yildirim, T.; Durgun, Engin; Senger, R. T.; Fong, C. Y.; Çıracı, Salim (American Physical Society, 2005)
      We found that magnetic ground state of one-dimensional atomic chains of carbon-transition-metal compounds exhibit half-metallic properties. They are semiconductors for one spin direction, but show metallic properties for ...
    • Hydrogen absorption properties of metal-ethylene complexes 

      Zhou. W.; Yildirim, T.; Durgun, Engin; Çıracı, Salim (American Physical Society, 2007)
      Recently, we have predicted that a single ethylene molecule can form stable complexes with light transition metals (TMs) such as Ti and the resulting TMn -ethylene complex can absorb up to ∼12 and 14 wt % hydrogen for n=1 ...
    • Hydrogen storage capacity of titanium met-cars 

      Akman, N.; Durgun, Engin; Yildirim, T.; Çıracı, Salim (IOP Publishing Ltd., 2006)
      The adsorption of hydrogen molecules on the titanium metallocarbohedryne (met-car) cluster has been investigated by using the first-principles plane wave method. We have found that, while a single Ti atom at the corner can ...
    • Metal nanoring and tube formation on carbon nanotubes 

      Bagci, V. M. K.; Gülseren, O.; Yildirim, T.; Gedik, Z.; Ciracil, S. (American Physical Society, 2002)
      The structural and electronic properties of aluminum-covered single-wall carbon nanotubes (SWNT's) are studied from first principles for a large number of coverages. Aluminum-aluminum interaction, that is stronger than ...
    • Molecular and dissociative adsorption of multiple hydrogen molecules on transition metal decorated C60 

      Yildirim, T.; Íñiguez, J.; Çıracı, Salim (American Physical Society, 2005)
      Recently we have predicted [Phys. Rev. Lett. 94, 175501 (2005)] that Ti-decorated carbon nanotubes can adsorb up to 8 wt.% hydrogen at ambient conditions. Here we show that a similar phenomenon occurs in light transition-metal ...
    • Oxygenation of carbon nanotubes: Atomic structure, energetics, and electronic structure 

      Dag, S.; Gülseren, O.; Yildirim, T.; Çıracı, Salim (American Physical Society, 2003)
      This paper presents an extensive and systematic analysis of the oxygenation of semiconducting and metallic single-wall carbon nanotubes by using the first principles pseudopotential plane wave method. Our study involves ...
    • Pentagonal nanowires: a first-principles study of the atomic and electronic structure 

      Sen, P.; Gülseren, O.; Yildirim, T.; Batra, I. P.; Çıracı, Salim (American Physical Society, 2002)
      We performed an extensive first-principles study of nanowires in various pentagonal structures by using pseudopotential plane wave method within the density functional theory. Our results show that nanowires of different ...
    • Pressure-induced interlinking of carbon nanotubes 

      Yildirim, T.; Gülseren, O.; Kiliç, Ç.; Çıracı, Salim (American Physical Society, 2000)
      We predict new forms of carbon consisting of one- and two-dimensional networks of interlinked single-wall carbon nanotubes, some of which are energetically more stable than van der Waals packing of the nanotubes on a ...
    • A recombinant PvpA protein-based diagnostic prototype for rapid screening of chicken mycoplasma gallisepticum infections 

      Büyüktanir, O.; Yildirim, T.; Yakicier, C.; Genç, O.; Yurdusev, N. (Elsevier, 2008)
      Mycoplasma gallisepticum is the primary agent of chronic respiratory disease causing important economic losses in the poultry industry. Serological monitoring is essential to maintain mycoplasma-free breeder flocks and ...
    • Reversible band-gap engineering in carbon nanotubes by radial deformation 

      Gülseren, O.; Yildirim, T.; Çıracı, Salim; Kılıç, Ç. (American Physical Society, 2002-03)
      We present a systematic analysis of the effect of radial deformation on the atomic and electronic structure of zigzag and armchair single wall carbon nanotubes using the first-principle plane wave method. The nanotubes ...
    • Storytelling in the stories of Efrâsiyâb 

      Yildirim, T. (2005)
      It is possible to find the traces of traditional storytelling in modern novels. In this study, the narrator's discourse in Ihsan Oktay Anar's Efrâsiyâb'in Hikâyeleri (The Stories of Afrasiab) is compared to the narrators ...
    • Systematic ab initio study of curvature effects in carbon nanotubes 

      Gülseren, O.; Yildirim, T.; Çıracı, Salim (American Physical Society, 2002)
      We investigate curvature effects on geometric parameters, energetics, and electronic structure of zigzag nanotubes with fully optimized geometries from first-principle calculations. The calculated curvature energies, which ...