3538 results
Search Results
Now showing 1 - 10 of 3538
Article Citation - WoS: 21Citation - Scopus: 21Synthesis and Electro-Optical Properties of New Conjugated Hybrid Polymers Based on Furan and Fluorene Units(Pergamon-elsevier Science Ltd, 2013) Gunes, Arzu; Cihaner, Atilla; Onal, Ahmet M.A novel series of hybrid monomers containing furan and fluorene units, namely 2-(2-(furan-2-yl)-9H-fluoren-7-yl)furan (FFF), 2,7-di(furan-2-yl)-9H-fluoren-9-one (FOF) and 2-(2-(furan-2-yl)-9,9-dihexyl-9H-fluoren-7-yl)furan (FHF), was synthesized and their electrochemical polymerization was achieved via potential cycling. Optical and electrochemical properties of the polymers, poly(2-(2-(furan-2-yl)9H-fluoren-7-yl)furan (PFFF), poly(2,7-di(furan-2-yl)-9H-fluoren-9-one) (PFOF) and poly(2-(2-(furan2-yl)-9,9-dihexyl-9H-fluoren-7-yl)furan) (PFHF), were investigated and it was found that polymer films exhibited quasi-reversible redox behavior (E-p(ox) =0.92V for PFFF, E-p(ox) = 1.08V for PFOF and E-p(ox) = 0.99V for PFHF) accompanied with a reversible electrochromic behavior, yellow to dark blue for PFFF, orange to green for PFOF and orange to green for PFHF. Their band gap values (E-g) were found to be 2.49, 2.32 and 2.61 eV for PFFF, PFOF and PFHF, respectively. (C) 2012 Elsevier Ltd. All rights reserved.Conference Object Citation - Scopus: 14A Decentralized Application for Secure Messaging in a Trustless Environment(Institute of Electrical and Electronics Engineers Inc., 2019) Abdulaziz,M.; Culha,D.; Yazici,A.Blockchain technology has been seeing widespread interest as a means to ensure the integrity, confidentiality and availability of data in a trustless environment. They are designed to protect data from both internal and external cyberattacks by utilizing the aggregated power of the network to resist malicious efforts. In this article, we will create our own decentralized messaging application utilizing the Ethereum Whisper protocol. Our application will be able to send encrypted messages both securely and anonymously. We will utilize the Ethereum platform to deploy our blockchain network. This application would be resistant to most suppression tactics due to its distributed nature and adaptability of its communication protocol. © 2018 IEEE.Article Citation - WoS: 25Citation - Scopus: 32High-Dimensional Optimization of Large-Scale Steel Truss Structures Using Guided Stochastic Search(Elsevier Science inc, 2021) Azad, Saeid Kazemzadeh; Aminbakhsh, Saman; Kazemzadeh Azad, SaeidDespite a plethora of truss optimization algorithms devised in the recent literature of structural optimization, still high-dimensional large-scale truss optimization problems have not been properly tackled basically due to the excessive computational effort required to handle the foregoing instances. In this study, application of a recently developed design-driven heuristic, namely guided stochastic search (GSS), is extended to a more challenging class of truss optimization problems having thousands of design variables. Two variants of the algorithm, namely GSSA and GSSB, have been employed for sizing optimization of four high-dimensional examples of steel trusses, i.e., a 2075-member single-layer onion dome, a 2688-member double-layer open dome, a 6000-member doublelayer scallop dome, and a 15048-member double-layer grid as per AISC-LRFD specification. The numerical results obtained indicate the efficiency of GSSA and GSSB in handling high-dimensional instances of large-scale steel trusses with up to 15048 discrete design variables.Article Usability Assessment of Scholarly Publishers' Online Journal Interfaces(Springernature, 2023) Peker, Serhat; Dalveren, Gonca Gokce MenekseA well-designed and user-friendly online journal interface not only enhances researchers' satisfaction but also bolsters the reputation of academic publishers within the scholarly community. Consequently, the present study undertakes an examination of the usability aspects pertaining to online journal interfaces offered by five prominent academic publishers: Wiley, Sage, Elsevier, Springer, and Taylor & Francis. This investigation encompasses a combination of user testing and post-questionnaire methodologies, aiming to accrue both quantitative and qualitative data concerning user task execution and satisfaction. The research findings spotlight the varying degrees of usability across major academic publishers and emphasize the critical role of design in enhancing researchers' experiences. By identifying both usability strengths and weaknesses, along with offering actionable areas for improvement, this study adds a valuable perspective to the enhancement of academic journal interfaces.Article Citation - Scopus: 8Computation of a Tunable Slot-Loaded Equilateral Triangular Microstrip Antenna(2009) Aydın,E.In this paper, a simple closed form expression is developed to accurately estimate the lower and upper operating frequencies of a single feed slot loaded triangular patch (SLTP) with variations of the bent slot lengths. It is obtained by using cavity model analysis and useful to antenna engineers for accurately predicting both operating resonant frequencies of the SLTP. The theory is compared with the experimental results available in the literature, and excellent agreement is observed. The proposed computation is also extended to the analysis of tunability of the SLTP as a function of the air-gap height. © Journal of electromagnetic waves and applications. All Rights reserved.Article Citation - WoS: 14Citation - Scopus: 22Simulation of the Flood Wave Caused by Hypothetical Failure of the Haditha Dam(Taylor & Francis Ltd, 2023) Mhmood, Harith Hamad; Yilmaz, Meric; Sulaiman, Sadeq OleiwiIn this research, the flood wave resulting from the hypothetical overtopping failure of the Haditha Dam on the Euphrates River, Iraq, was simulated, utilizing the ArcMap 10.2 and HEC-RAS 5.0.7 software and the observed field data from the Iraqi Ministry of Water Resources. Flooding parameters were calculated, for the study reach from the Haditha Dam to Heet city and major cities in between. The Manning coefficient of the study reach was calibrated to 0.035 and 0.07 for the main river and the floodplain, respectively. The results showed the flood wave propagation along the study reach, the flood hydrograph and time to the peak discharge/time to the maximum water surface elevation, maximum velocity, and width of the inundated area at the selected cities. The analysis outputs and the inundation maps can be used to provide an emergency action plan for the flooded regions.Letter Citation - WoS: 3Citation - Scopus: 3Global Robust Stability of Interval Delayed Neural Networks: Modified Approach(Wiley, 2009) Singh, VimalA criterion for the global robust stability of Hopfield-type delayed neural networks with the intervalized network parameters is presented. The criterion, which is derived by utilizing the idea of splitting the given interval into two intervals, is in the form of linear matrix inequality and, hence, computationally tractable. The criterion yields a less conservative condition compared with many recently reported criteria, as is demonstrated with an example. Copyright (C) 2008 John Wiley & Sons, Ltd.Article Citation - WoS: 13Citation - Scopus: 12Oscillation Criterion for Half-Linear Differential Equations With Periodic Coefficients(Academic Press inc Elsevier Science, 2012) Dosly, O.; Ozbekler, A.; Simon Hilscher, R.In this paper, we present an oscillation criterion for second order half-linear differential equations with periodic coefficients. The method is based on the nonexistence of a proper solution of the related modified Riccati equation. Our result can be regarded as an oscillatory counterpart to the nonoscillation criterion by Sugie and Matsumura (2008). These two theorems provide a complete half-linear extension of the oscillation criterion of Kwong and Wong (2003) dealing with the Hill's equation. (C) 2012 Elsevier Inc. All rights reserved.Article Citation - WoS: 7Citation - Scopus: 6Parametric Analysis of Viscoelastic Hyperboloidal Helical Rod(Sage Publications inc, 2016) Ermis, M.; Eratli, N.; Argeso, H.; Kutlu, A.; Omurtag, M. H.The objective of this study is to perform a pioneering research about a viscoelastic hyperboloidal helical rod having a standard type of distortional behavior and a Kelvin type of bulk compressibility. Field equations are based on the Timoshenko beam theory, and the exact curvatures of the hyperboloidal geometry are considered through the formulation. The numerical analysis is carried out by the mixed finite element method, considering the rotary inertia, in the Laplace space, and the results are transformed back to time space numerically using the modified Durbin's algorithm. A cantilevered hyperboloidal helical rod having solid circular, hollow circular, and thin-walled hollow circular cross sections is handled, and the rod is loaded by rectangular and triangular impulsive types of point load at the tip. Through the analysis, different values of retardation time, three different relaxation functions associated with shear modulus, and three different creep functions associated with bulk modulus are handled. Finally, a benchmark example is presented, and the influence of the loading and the material parameters on the helix geometry is discussed.Article Citation - WoS: 13Citation - Scopus: 14BIFURCATIONS AND HYPERCHAOS FROM A DC DRIVEN NONIDENTICAL JOSEPHSON JUNCTION SYSTEM(World Scientific Publ Co Pte Ltd, 2010) Kurt, Erol; Canturk, MehmetThe dynamics of a resistively coupled system of nonidentical Josephson junctions (JJ) with dc feedings is explored theoretically. The effects of system parameters on the dynamic features are defined and equilibrium features of the system of equations are explored in such a nonidentical JJ system for the first time. By using center manifold reduction, the inverse of coupling resistance R-cp is considered as the main bifurcation parameter. The bifurcation at the vicinity of the equilibrium point is found to be transcritical, stable and unstable regimes are also indicated analytically. It is observed that the amplitudes of the output voltages on the coupling resistance R-cp are changeable and mostly uncorrelated for two parts of superconducting junction system. Such a system exhibits very rich dynamics from periodic to chaotic behavior for certain parameter sets. While the regular characteristics are observed for moderate and lower feeding currents, chaotic and highly-complex patterns are obtained for relatively higher values of them. Besides, a wider hyperchaotic region is found for wide ranges of parameters after the determination of phase diagrams compared to the earlier studies. The nonidentical nature of JJs governs the complicated dynamics on the phase space. The present circuitry can be utilized for various purposes such as stable, chaotic or hyperchaotic behavior depending on the parameters I-i and R-cp.
