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Article Citation - WoS: 44Citation - Scopus: 45A Novel Electrochromic and Fluorescent Polythienylpyrrole Bearing 1,1′-Bipyrrole(Pergamon-elsevier Science Ltd, 2009) Cihaner, Atilla; Mert, Olcay; Demir, Ayhan S.A novel conducting polymer was successfully synthesized via electropolymerization of 1-(1H-pyrrol-1-yl)-2,5-di(thiophen-2-yl)-1H-pyrrole. The electrochemical and electro-optical properties of the corresponding polymer, which was the first example of polymer containing 1,1'-bipyrrole units, were elaborated using electroanalytical and spectroscopic techniques. Cyclic voltammograms and electro-optical studies showed that the polymer has a stable and well-defined reversible redox process as well as electrochromic behavior. The processable polymer film also possessed a yellowish orange light emitter property. (C) 2008 Elsevier Ltd. All rights reserved.Article Citation - WoS: 94Citation - Scopus: 95A New Conducting Polymer Bearing 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (bodipy) Subunit: Synthesis and Characterization(Pergamon-elsevier Science Ltd, 2008) Cihaner, Atilla; Algi, FatihA new monomer system based on thiophene, pyrrole and 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene dye (SNS-BODIPY) was synthesized and its corresponding polymer (PSNS-BODIPY) was obtained via repetitive cycling or constant potential electrolysis in 0.1 M tetrabutylammonium hexafluorophosphate dissolved in dichloromethane. The PSNS-BODIPY film has very stable and well-defined reversible redox couples during p-doping process. Multi-electrochromic polymer film has a band gap of 2.9 eV with two absorption bands in its neutral state at 351 and 525 nm, attributed to the polymer backbone and BODIPY subunits, respectively. The percentage transmittance changes between both states (neutral and oxidized) were found as 12.1% for 351 nm and 17.7% for 525 nm in the visible region as well as 46.2% for 1050 nm in the near-infrared region. Beyond the robustness, the PSNS-BODIPY film has high redox stability (retaining 53.3% of its electroactivity at 351 nm after 2000 switching) with a low response time of 1.0 s. (C) 2008 Elsevier Ltd. All rights reserved.Article Citation - WoS: 102Citation - Scopus: 113A 1.6-Mm, Metal Tube Ultrasonic Motor(Ieee-inst Electrical Electronics Engineers inc, 2003) Cagatay, S; Koc, B; Uchino, KA miniaturized metal tube ultrasonic motor, the dimensions of which are 1.6 mm in diameter and 6 rum in length, was developed. Two flattened surfaces with 90-degrees were ground on the outer surface of the stator. Two PZT-based piezoelectric ceramics were bonded onto these flat surfaces. The asymmetrical surface of the stator developed the split of the two degenerated orthogonal bending modes, resulting in a wobble motion. The working frequency of the 1.6-mm motor with 6 mm in length was 130 kHz. A torque of 0.5 mNm was reached at a maximum power of 45 mW with a speed of 45 rad/sec. The maximum efficiency was 16%.Article Citation - WoS: 40Citation - Scopus: 52Variable Structure Control of a Class of Uncertain Systems(Pergamon-elsevier Science Ltd, 2004) Efe, MÖ; Ünsal, C; Kaynak, O; Yu, XHThis brief paper proposes a method for tuning the parameters of a variable structure controller. The approach presented extracts the error at the output of the controller and applies a nonlinear tuning law using this error measure. The adaptation mechanism drives the state tracking error vector to the sliding hypersurface and maintains the sliding mode. In the simulations, the approach presented has been tested on the control of Dulling oscillator and the analytical claims have been justified under the existence of measurement noise, uncertainty and large nonzero initial errors. (C) 2003 Elsevier Ltd. All rights reserved.Article Citation - WoS: 37Citation - Scopus: 39A New Refined Form of Jordan's Inequality and Its Applications(Pergamon-elsevier Science Ltd, 2006) Özban, AY; MathematicsA new refined form of Jordan's inequality [D.S. Mitrinovic, Analytic Inequalities, Springer-Verlag, 1970; F. Yuefeng, Jordan's inequality, Math. Mag. 69 (1996) 126] is proved and an application of it, together with some numerical results, are given. (C) 2005 Elsevier Ltd. All rights reserved.Article Citation - WoS: 21Citation - Scopus: 20Cartan-Slodkowski Spectra, Splitting Elements and Noncommutative Spectral Mapping Theorems(Academic Press inc Elsevier Science, 2006) Dosiev, AIn this paper, we prove Slodkowski version of the infinite-dimensional spectral mapping theorem and Cartan-Slodkowski version of the finite-dimensional spectral mapping theorem for nilpotent operator Lie subalgebras with respect to the various noncommutative functional calculi. (C) 2005 Elsevier Inc. All rights reserved.Article Citation - WoS: 33Citation - Scopus: 46Higher-Order Self-Adjoint Boundary-Value Problems on Time Scales(Elsevier Science Bv, 2006) Anderson, Douglas R.; Guseinov, Gusein Sh.; Hoffacker, JoanIn this study, higher-order self-adjoint differential expressions on time scales and their associated self-adjoint boundary conditions are discussed. The symmetry property of the corresponding Green's functions is shown, together with specific formulas of Green's functions for select time scales. (c) 2005 Elsevier B.V. All rights reserved.Conference Object Citation - WoS: 1The Generalized Divergence Theorem and Its Application To Harmonic Maps(Pergamon-elsevier Science Ltd, 2001) García-Río, E; Kupeli, DNA survey of divergence theorems in semi-Riemannian geometry is made. The generalization of a divergence theorem to vector fields along a map is given in semi-Riemannian geometry and an application of it is made in Riemannian geometry to obtain some sufficient conditions for a map to be harmonic.Article Citation - WoS: 3Instability Intervals of a Hill's Equation With Piecewise Constant and Alternating Coefficient(Pergamon-elsevier Science Ltd, 2004) Guseinov, GS; Karaca, IYIn this paper, we obtain asymptotic formulas for eigenvalues of the periodic and the semiperiodic boundary value problems associated with a Hill's equation having piecewise constant and alternating coefficient. As a corollary, it is shown that the lengths of instability intervals of the considered Hill's equation tend to infinity. (C) 2004 Elsevier Ltd. All rights reserved.Article Citation - WoS: 9Citation - Scopus: 9The Approximation of Logarithmic Function by q-bernstein Polynomials in the Case q > 1(Springer, 2007) Ostrovska, SofiyaSince in the case q > 1, q-Bernstein polynomials are not positive linear operators on C[ 0, 1], the study of their approximation properties is essentially more difficult than that for 0 < q < 1. Despite the intensive research conducted in the area lately, the problem of describing the class of functions in C[ 0, 1] uniformly approximated by their q-Bernstein polynomials ( q > 1) remains open. It is known that the approximation occurs for functions admitting an analytic continuation into a disc {z : | z| < R}, R > 1. For functions without such an assumption, no general results on approximation are available. In this paper, it is shown that the function f ( x) = ln( x + a), a > 0, is uniformly approximated by its q-Bernstein polynomials ( q > 1) on the interval [ 0, 1] if and only if a >= 1.
