Now showing items 1-20 of 4048

    • Structural, optical and photocatalytic properties of pvc/cds nanocomposites prepared by soft chemistry method 

      Rouabah, N.; Boudine, B.; Nazır, Roshan; Zaabat, M.; Sebais, M.; Halimi, O.; Soltani, M. T.; Chala, A. (Springer, 15-09-2020)
      This work investigates the preparation of cadmium sulfde nanoparticles (CdS) embedded in the polymeric polyvinylchloride (PVC) matrix. PVC/CdS nanocomposite flms were prepared via sol–gel method with deposition by spin-coating ...
    • Sedimentation rates in the central lake constance determined with210Pb and137Cs 

      von Gunten, H. R.; Sturm, M.; Erten, H. N.; Rössler, E.; Wegmüller, F. (Birkhäuser-Verlag, 1987)
      Sediment cores from central Lake Constance were dated with210Pb and137Cs. A sedimentation rate of (0.11±0.02) g·cm-2·y-1 was determined with the210Pb method.137Cs measurements revealed sedimentation rates of (0.11±0.01) ...
    • Molecular-dynamics study of self-interstitials in silicon 

      Batra, I. P.; Abraham, F. F.; Çıracı, Salim (American Physical Society, 1987)
      Results of a molecular-dynamics computer simulation are presented for atomic relaxations and relaxation energies for self-interstitials in a silicon crystal. The Stillinger-Weber model potential containing two- and three-body ...
    • Scanning-tunneling microscopy at small tip-to-surface distances 

      Çıracı, Salim; Batra, I. P. (1987)
      The scanning-tunneling microscopy (STM) of graphite at small tip-to-surface distances is investigated using the self-consistent-field pseudopotential method. We have calculated potential, charge density in the region between ...
    • Long-range order and segregation in semiconductor superlattices 

      Çıracı, Salim; Batra, I. P. (1987)
      Results of self-consistent energy-minimization calculations provide strong evidence that the ordered phases in epitaxially grown Ga1-xAlxAs and strained Si1-xGex alloys are metastable, in the sense that segregation into ...
    • Metallization of Silicon upon Potassium Adsorption 

      Çıracı, Salim; Batra, I. P. (1987)
      We report novel features of potassium deposition on a Si(111)-(2×1) surface as a function of coverage. The binding is ionic even at the saturation coverage without any overlayer metallization. Up to a threshold coverage, ...
    • Efficiency calibration and summation effects in gamma-ray spectrometry 

      Erten, H. N.; Aksoyoğlu, S.; Göktürk, H. (Kluwer Academic Publishers, 1988)
      Precise, absolute γ-ray efficiences (∈γ) and total efficiences (∈T), have been measured at various distances from the detector, using a set of standards. The observed linear variation of ∈γ and ∈T as well as ∈γ/∈T with Eγ ...
    • An isomorphism theorem for Dragilev spaces 

      Kocatepe, M. (Birkhäuser-Verlag, 1988)
      Necessary and sufficient conditions for an Ly(a, l)-space to be isomorphic to some Lg(b, m)-space have been found.
    • Critical relaxation of the two-dimensional three-state Potts model with conserved dynamics 

      Aydın, M.; Yalabık, M. C. (Institute of Physics (Great Britain), 1988)
      The dynamical critical exponent z is obtained using the finite-size scaling method for the two-dimensional three-state Potts model with conserved dynamics. It is observed that there is a change in the dynamical behaviour ...
    • Sorption of cesium and strontium on montmorillonite and kaolinite 

      Erten, H. N.; Aksoyoglu, S.; Hatipoglu, S.; Göktürk, H. (De Gruyter Oldenbourg, 1988)
      Sorption characteristics of Cs+ and Sr++on montmorillonite and kaolinite type clays and soil fractions from various regions of Turkey were studied using the batch method. 137Cs and 90Sr were used as tracers. Concentrations ...
    • Sorption/desorption of Cs on clay and soil fractions from various regions of Turkey 

      Erten, H. N.; Aksoyoglu, S.; Göktürk, H. (Elsevier, 1988)
      The sorption desorption behaviour of Cs ion in the concentration region of 10−8 to 10−4 meqml−1 have been studied using clay and soil fractions from various regions of Turkey. The sorption curves for all the material studied ...
    • C∗-actions on Grassmann bundles and the cycle at infinity. 

      Sertöz, S. (Aarhus Universitet * Mathematica Scandinavica, 1988)
      We describe the Grassmann Graph construction of MacPherson in the analytic category using a C∗-action and the corresponding BialynickiBirula decomposition. It is shown that the cycle at infinity is analytic in the compact ...
    • Effect of tip profile on atomic-force microscope images: a model study 

      Abraham, F. F.; Batra, I. P.; Çıracı, Salim (American Physical Society, 1988)
      Adopting the empirical silicon interatomic potential of Stillinger and Weber, we investigate the effect of the tip profile on the atomic-force microscope images for a prototype system, Si(001)-(2×1), and conclude that the ...
    • Surface metallization of silicon by potassium adsorption on Si(001)-(2×1) 

      Çıracı, Salim; Batra, I. P. (American Physical Society, 1988)
      We present the detailed results of self-consistent and geometry-optimized total-energy, band-structure, and charge-density calculations for a potassium-covered Si(001)-(2×1) surface, and for an unsupported potassium ...
    • Delta-Doping in strained (Si) / (Ge) superlattices 

      Çıracı, Salim; Batra, I. P.; Tekman, E. (American Physical Society, 1988)
      We present a comparative study of the pseudomorphic (Si)6/(Ge)6 and -doped (Si)3(Sb)(Si)2/(Ge)6 superlattices using the self-consistent pseudopotential method. The strained (Si)6/(Ge)6 superlattice has the lowest conduction-band ...
    • Electronic structure of strained Sin / Gen (001) superlattices 

      Çıracı, Salim; Gülseren, O.; Ellialtioğlu, Ş. (Pergamon Press, 1988)
      Using the empirical tight binding method we have investigated the electronic properties of the Sin/Gen(001) strained superlattices as a function of the superlattice periodicity and the band misfit. For n ≥ 4 we have found ...
    • Tip induced localized states in scanning tunneling microscopy 

      Tekman, E.; Çıracı, Salim (Institute of Physics Publishing Ltd., 1988)
      We have investigated the Scanning Tunneling Microscopy (STM) of graphite with varying tip-to-surface distance. Using an LCAO type approach we showed that at small separations states are localized between the tip and the ...
    • Calculations of STM linescans-general formalism 

      Ellialtioğlu, Ş.; Çıracı, Salim; Batra, I. P. (Pergamon Press, 1988)
      We have developed a formalism for calculating the line scans of the scanning-tunneling microscopy from the realistic substrate and tip wave functions. The tip wave functions are calculated self-consistently by using a ...
    • Simulated annealing for texture segmentation with Markov models 

      Yalabık, M. Cemal; Yalabık, N. (IEEE, 1989)
      Binary textured images are segmented into regions of different textures. The binary Markov model is used, and model parameters are assumed to be unknown prior to segmentation. The parameters are estimated using a ...
    • A Monte Carlo study of the BNNNI model 

      Aydin, M.; Yalabik, M. C. (IOP Publishing, 1989)
      The biaxially next-nearest-neighbour Ising (BNNNI) model is studied using the Monte Carlo procedure. The structure factor is used to identify the possible phases of the system. At intermediate temperatures, evidence for ...