Yazar "Ozkaner, Vedat" seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • Küçük Resim
    Öğe
    Chiral metamaterial design using optimized pixelated inclusions with genetic algorithm
    (Spie-Soc Photo-Optical Instrumentation Engineers, 2015) Akturk, Cemal; Karaaslan, Muharrem; Ozdemir, Ersin; Ozkaner, Vedat; Dincer, Furkan; Bakir, Mehmet; Ozer, Zafer
    Chiral metamaterials have been a research area for many researchers due to their polarization rotation properties on electromagnetic waves. However, most of the proposed chiral metamaterials are designed depending on experience or time-consuming inefficient simulations. A method is investigated for designing a chiral metamaterial with a strong and natural chirality admittance by optimizing a grid of metallic pixels through both sides of a dielectric sheet placed perpendicular to the incident wave by using a genetic algorithm (GA) technique based on finite element method solver. The effective medium parameters are obtained by using constitutive equations and S parameters. The proposed methodology is very efficient for designing a chiral metamaterial with the desired effective medium parameters. By using GA-based topology, it is proven that a chiral metamaterial can be designed and manufactured more easily and with a low cost. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)
  • [ N/A ]
    Öğe
    Investigations into the cutting and wear characteristics of TiCN-CrN coated C 80 steels
    (Carl Hanser Verlag, 2008) Cakan, Ahmet; Ozkaner, Vedat; Yildirim, M. Mustafa
    Hard coatings of titanium carbonitrides (TiCN) and chromium nitrides (CrN) are now commonly used to protect the surfaces of cutting tools from the effects of wear and corrosion. In the work presented here the surfaces of the cutting edges of tools made of unalloyed C80 steel are coated with a thin layers of TiCN and CrN coatings using the Cathodic Arc-Vapour (CAVD) deposition technique. The cutting characteristics and wear behaviour of the cutting tools so treated were then investigated experimentally on a conventional lathe. The change in the chemical composition and properties of the nitride coated surfaces is investigated using both SEM photography with line scan analysis and by X-ray diffraction (XRD). Cutting tests and wear behaviour of tools, the cutting edges of which were coated with very thin TiCN and CrN coatings, were investigated directly using an on-line monitoring system. Amongst other things the results revealed the TiCN coated cutting tools to be more wear resistant than those coated with CrN coatings.
  • [ N/A ]
    Öğe
    A Markov model developed for sodium channel currents in cerebellar Purkinje neurons
    (Ieee, 2006) Ozkaner, Vedat; Kayikcioglu, Temel
    In this study, a Markov model for gating kinetics of sodium channel currents in dissociated cerebellar Purkinje neurons is developed. The model is based on voltage-clamped, resurgent and action potential evoked currents, known as macroscopic currents. It is different from previously developed models. In this model, some-modifications are made in the number of states and channel rate constants. The model parameters are determined using trial and error procedure to minimizing the error between model responses and three experimental data sets. The developed sodium channel model reproduces quantitatively all features of the experimental data sets, with minor discrepancies.
  • Küçük Resim
    Öğe
    Quantifying Cutting and Wearing Behaviors of TiN- and CrN-Coated AISI 1070 Steel
    (Mdpi, 2008) Cakan, Ahmet; Ozkaner, Vedat; Yildirim, Mustafa M.
    Hard coatings such as titanium nitride (TiN) and chromium nitride (CrN) are widely used in cutting and forming tools against wear and corrosion. In the present study, hard coating films were deposited onto AISI 1070 steels by a cathodic arc evaporation plating ( CAVP) technique. These samples were subjected to wear in a conventional lathe for investigating the tribological behaviour of coating structure, and prenitrided subsurface composition was characterized using scanning electron microscopy (SEM), line scan analyses and X-ray diffraction ( XRD). The wear properties of TiN- and CrN-coated samples were determined using an on-line monitoring system. The results show that TiN- coated samples demonstrate higher wear resistance than CrN-coated samples.