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Article Citation - WoS: 1Citation - Scopus: 1Spectroelectrochemical Investigation of the Anodic Oxidation of Dibenzo-18(Elsevier Science Sa, 2004) Cihaner, A; Önal, AMPoly(dibenzo-18-crown-6) (poly-DB18C6) was synthesized by electrochemical oxidation of dibenzo-18-crown-6 (DB18C6) using a mixture of acetonitrile and dichloromethane as the solvent and tetrabutylammonium tetrafluoroborate (TBABF(4)) or tetrabutylammonium hexafluorophosphate (TBAPF(6)) as supporting electrolyte. The anodic polymerization of DB18C6 was investigated using in situ ESR and in situ UV-Vis spectroscopic techniques. Spectroelectrochemical (SPEL), properties and thermal analysis of the resulting polymers have been investigated using UV-Vis spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). (C) 2004 Elsevier B.V. All rights reserved.Publication China-Africa Relations in the 21st Century : Engagement,compromise and Controversy(2009) Uchehara, E.kieranÇin’in Afrika ile ilgili dış politika gündemi, gelişmekte olan ülkeler arasındaki işbirliğini artırma ve yükselen bir süper güç olarak statüsünü gösterme hamlesinin bir parçasını oluşturmaktadır. 2000 Pekin Deklarasyonu ve Çin-Afrika Ekonomik ve Siyasi işbirliği Programı yenilenen ilişkilerin temelini oluşturmaktadır. Çin, Afrika ile tüm karşılıklı ilişki alanlarında Afrika ile farklı ve çeşitli ilişkiler geliştirmiştir. Ancak Çin’in büyüyen sanayisinin ihtiyaç duyduğu Afrika’nın maden ve enerji kaynakları, 21. yüzyılda Çin’in Afrika ile iyi ilişkiler kurmasının ana sebebidir. Çin’in Afrika’daki ticaret ve yatırımındaki hızlı artış, kıtanın kalkınması ile ilgili fırsatlar ve zorlukların yapısına ilişkin ve Batı ile olduğu gibi yeni-sömürgeci tarzı ilişkilerin gelişme ihtimalinin olup olmadığı konusunda akademisyenler ve siyasiler arasındaki uyuşmazlıkları açığa çıkarmıştır. Kısmen ekonomik asimetrilerden kaynaklanan ticari ve yatırım ilişkilerindeki dengesizlik, Çin’in Afrikalı baskıcı yönetimleri kınamaması ve iyi yönetilmeyen ekonomiler; kendisine hizmet eden ve kısa dönem kazanımlardan etkilenen bir dış ekonomik politikayı işaret etmektedir.Article Citation - WoS: 47Citation - Scopus: 68On the Positive Solutions of the System of Rational Difference Equations(Academic Press inc Elsevier Science, 2006) Ozban, Ahmet YasarOur aim in this paper is to investigate the periodic nature of solutions of the system of rational difference equations x(n+1) = 1/y(n-k), y(n+1) = yn/x(n-mYn-m-k), n = 0, 1,..., where k is a nonnegative integer, m is a positive integer and the initial values x(-m), x(-m+1),..., x(0), y(-m-k), y(-m-k+1),..., y(0) are positive real numbers. (c) 2005 Elsevier Inc. All rights reserved.Article Citation - Scopus: 1Adaptive Neuro-Fuzzy Inference Technique for Estimation of Light Penetration in Reservoirs(Springer Japan Kk, 2007) Soyupak, Selcuk; Karaer, Feza; Senturk, Engin; Hekim, HuseyinAn adaptive neuro-fuzzy inference technique has been adopted to estimate light levels in a reservoir. The data were collected randomly from Doganci Dam Reservoir over a number of years. The input data set is a matrix with vectors of time, depth, sampling location, and incident solar radiation. The output data set is a vector representing light measured at various depths. Randomization and logarithmic transformations have been applied as preprocessing. One-half of the data have been utilized for training; testing and validation steps utilized one-fourth each. An adaptive neuro-fuzzy inference system (ANFIS) has been built as a prediction model for light penetration. Very high correlation values between predictions and real values on light measurements with relatively low root mean square error values have been obtained for training, test, and validation data sets. Elimination of the overtraining problem was ensured by satisfying close root mean square error values for all sets.Article Citation - WoS: 21Citation - Scopus: 21Special Standard Static Space-Times(Pergamon-elsevier Science Ltd, 2004) Dobarro, F; Ünal, BEssentially, some conditions for the Riemannian factor and the warping function of a standard static space-time are obtained in order to guarantee that no nontrivial warping function on the Riemannian factor can make the standard static space-time Einstein. (C) 2004 Elsevier Ltd. All rights reserved.Article Citation - WoS: 39Citation - Scopus: 44Application of Continuum Damage Mechanics in Discontinuous Crack Formation: Forward Extrusion Chevron(Wiley-v C H verlag Gmbh, 2008) Soyarslan, Celal; Tekkaya, A. Erman; Akyuz, UgurhanMaterializing Continuum Damage Mechanics (CDM), numerical modeling of discrete internal cracks, namely central bursts, in direct forward extrusion process is presented. Accordingly, in a thermodynamically consistent setting, a local Lemaitre variant damage model with quasi-unilateral evolution is coupled with hyperelastic-plasticity. The formulations are constructed in the principal axes where simultaneous local integration schemes are efficiently developed. To this end, the framework is implemented as ABAQUS/VUMAT subroutine to be used in an explicit FE solution scheme, and utilized in direct forward extrusion simulations for bearing steel, 100Cr6. Discontinuous cracks are obtained with the element deletion procedure, where the elements reaching the critical damage value are removed from the mesh. The periodicity of the cracks shows well accordance with the experimental facts. The investigations reveal that, application of the quasi-unilateral conditions together with the crack closure parameter has an indispensable effect on the damage accumulation zones by determining their internal or superficial character. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Article Citation - WoS: 41Citation - Scopus: 48Platinated Copper(3-Clip Complexes as Effective Dna-Cleaving and Cytotoxic Agents(Wiley-v C H verlag Gmbh, 2008) Ozalp-Yaman, Seniz; de Hoog, Paul; Amadei, Giulio; Pitie, Marguerite; Gamez, Patrick; Dewelle, Janique; Reedijk, JanThe synthesis and biological activity of three heteronuclear platinum-copper complexes based on 3-Clip-Phen are reported. These rigid complexes have been designed to alter the intrinsic mechanism of action of both the platinum moiety and the Cu(3-Clip-Phen) unit. The platinum centers of two of these complexes are coordinated to a 3-Clip-Phen moiety, an ammine ligand and two chlorides, which are either cis or trans to each other. The third complex comprises two 3-Clip-Phen units and two chloride ligands bound in a trans fashion to the platinum ion. DNA-cleavage experiments show that the complexes are highly efficient nuclease agents. In addition, a markedly difference in their aptitude to perform direct double-strand cleavage is observed, which appears to be strongly related to the ability of the platinum unit to coordinate to DNA. Indeed, complex 6 is unable to coordinate to DNA, which is reflected by its incapability to carry out double-strand breaks. Nonetheless, this complex exhibits efficient DNA-cleavage activity, and its cytotoxicity is high for several cell lines. Complex 6 shows better antiproliferate activity than both cisplatin and Cu(3-Clip-Phen) toward most cancer cell lines. Furthermore, the cytotoxicity observed for 1 is for most cell lines close to that of cisplatin, or even better. Cu(3-Clip-Phen) induces very low cytotoxic effects, but a marked migratory activity. Complex 6 presents DNA-cleavage properties comparable to the one of Cu(3-Clip-Phen), but it does not show any migratory activity. Interestingly, both Cu(3-Clip-Phen) and 6 induces vacuolisation processes in the cell in contrast to complex 1 and cisplatin. Thus, the four complexes cisplatin tested, Cu(3-Clip-Phen), I and 6 stimulate different cellular responses.Article Citation - WoS: 19Citation - Scopus: 20Human Body Shadowing Variability in Short-Range Indoor Radio Links at 3-11 Ghz Band(Taylor & Francis Ltd, 2009) Kara, AliMeasurement results for human body shadowing and local environmental effects in short-range indoor radio channels are presented. A narrowband measurement system, comprising a signal generator, two identical triangular monopoles and a spectrum analyser, was used in the measurements. When the radio link was periodically blocked by a human body with various objects in and around the link, fading depths of up to 15dB and even more were observed at spot frequencies of 3-11GHz band. Standard deviation and its range for human body blockage are estimated for different radio link scenarios simulating real environments. The distribution of human body shadowing was analysed and compared with known distribution functions.Article Citation - WoS: 26Citation - Scopus: 31New Lmi Condition for the Nonexistence of Overflow Oscillations in 2-D State-Space Digital Filters Using Saturation Arithmetic(Academic Press inc Elsevier Science, 2007) Singh, VimalA new criterion for the nonexistence of overflow oscillations in 2-D state-space digital filters described by Roesser model using saturation arithmetic is presented. The criterion is in the form of a linear matrix inequality (LMI) and hence computationally tractable. The criterion is compared with an earlier LMI-based criterion due to Xiao and Hill. It turns out that the present criterion may uncover some new A (i.e., other than those arrived at via Xiao-Hill's criterion) for which the absence of overflow oscillations is assured. (c) 2006 Elsevier Inc. All rights reserved.Article Citation - WoS: 4Citation - Scopus: 4Multi Input Dynamical Modeling of Heat Flow With Uncertain Diffusivity Parameter(Taylor & Francis inc, 2003) Efe, MÖ; Özbay, HThis paper focuses on the multi-input dynamical modeling of one-dimensional heat conduction process with uncertainty on thermal diffusivity parameter. Singular value decomposition is used to extract the most significant modes. The results of the spatiotemporal decomposition have been used in cooperation with Galerkin projection to obtain the set of ordinary differential equations, the solution of which synthesizes the temporal variables. The spatial properties have been generalized through a series of test cases and a low order model has been obtained. Since the value of the thermal diffusivity parameter is not known perfectly, the obtained model contains uncertainty. The paper describes how the uncertainty is modeled and how the boundary conditions are separated from the remaining terms of the dynamical equations. The results have been compared with those obtained through analytic solution.
