6 results
Search Results
Now showing 1 - 6 of 6
Article Citation - WoS: 20Citation - Scopus: 28Reliability Analysis of Consecutive k-out-of-n< Systems With Non-Identical Components Lifetimes(Elsevier Science Bv, 2011) Salehi, E. T.; Asadi, M.; Eryilmaz, S.In recent years, the study of reliability properties of consecutive k-out-of-n systems has attracted a great deal of attention from both theoretical and practical perspectives. In this paper we consider linear and circular consecutive k-out-of-n systems. It is assumed that lifetimes of components of the systems are independent but their probability distributions are non-identical. We study the reliability properties of the residual lifetimes of such systems under the condition that at least (n - r + 1), r <= n, components of the system are operating. We also investigate the probability that a specific number of components of the above-mentioned system operate at time t, t > 0, under the condition that the system is alive at time t. (C) 2011 Elsevier B.V. All rights reserved.Article Citation - WoS: 5Citation - Scopus: 5Electrical Behavior of Pb1.83mg0.29< Pyrochlore Ceramics(Elsevier Science Bv, 2004) Mergen, A; Kayed, TSPb1.83Mg0.29Nb1.71O6.39 pyrochlore was produced via a simple partial oxalate method. It was examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Single phase, belonging to the cubic pyrochlore structure, with a lattice parameter of a = 10.60125 +/- 0.001 Angstrom and grain size that varies from 5 to 10 mum was obtained. The electrical properties were measured at different temperatures in the range 15-320 K without and with applied magnetic field of 1.4 T. Current-voltage characteristics data were fitted to a power law expression V=I-beta(T) in which the exponential parameter beta takes values around 1 at all temperatures except at 300 K. Resistance starts from 3.3 x 10(10) Omega at 15 K and increases gradually to 4.8 x 10(10) Omega at 240 K. It drops to approximately 1.2 x 10(10) Omega at 300 K, after which it increases again to around 1.6 x 10(10) Omega at 320 K. (C) 2004 Elsevier B.V. All rights reserved.Article Citation - WoS: 45Citation - Scopus: 45An Ambipolar Low Band Gap Material Based on Bodipy and Edot(Elsevier Science Bv, 2009) Algi, Fatih; Cihaner, AtillaA novel donor-acceptor type conducting polymer based on BODIPY dye as acceptor and EDOT units as donor parts is synthesized electrochemically. The unique combination of BODIPY and EDOT units provides an ambipolar (n- and p-doping processes) low band gap material (4). This is the first example of p-n junction in an organic pi-conjugated material where BODIPY unit is incorporated directly in the main chain. Furthermore, the polymer film exhibits electrochromic behavior upon p-doping: a color change from light violet (neutral) to indigo (oxidized). (C) 2009 Elsevier B.V. All rights reserved.Article Citation - WoS: 15Citation - Scopus: 13K+-induced Conformational Changes in the Trimeric Betaine Transporter Betp Monitored by Atr-Ftir Spectroscopy(Elsevier Science Bv, 2013) Korkmaz, Filiz; Ressl, Susanne; Ziegler, Christine; Maentele, WernerThe trimeric Na+-coupled betaine symporter BetP from Corynebactrium glutamicum adjusts transport activity according to the external osmolality. BetP senses the increasing internal K+ concentration, which is an immediate consequence of osmotic upshift in C. glutamicum. It is assumed that BetP specifically binds potassium to yet unidentified binding sites, thereby inducing conformational changes resulting in activation. Atomic structures of BetP were obtained in the absence of potassium allowing only a speculative glimpse on a putative mechanism of K+-induced transport activation. The structural data suggest that activation in BetP is crucially linked to its trimeric state involving an interaction network between several arginines and glutamates and aspartates. Here, we describe the effect of K+-induced activation on the specific ionic interaction sites in terminal domains and loops and on the protomer-protomer interactions within the trimer studied by ATR-FTIR spectroscopy. We suggest that arginine and aspartate and/or glutamate residues at the trimeric interface rearrange upon K+-induced activation, although they remain assembled in an interaction network. Our data propose a two-step mechanism comprising first a change in solvent exposure of charged residues and second a modification of their interaction sites in a partner-switching manner. FTIR reveals a higher alpha-helical content than expected from the X-ray structures that we attribute to the structurally unresolved N-terminal domain modulating regulation. In situ H-1/H-2 exchange studies point toward an altered exposure of backbone regions to buffer solution upon activation, most likely due to conformational changes in both terminal domains, which further affects ionic interactions within the trimer. (C) 2013 Elsevier B.V. All rights reserved.Article Citation - WoS: 23Citation - Scopus: 25A Neutral State Yellow To Navy Polymer Electrochrome With Pyrene Scaffold(Elsevier Science Bv, 2011) Icli-Ozkut, Merve; Cihaner, Atilla; Oztas, Zahide; Algi, Fatih; Cihaner, Atilla; Cihaner, Atilla; Chemical Engineering; Chemical EngineeringA new pyrene based soluble polymer, namely poly(3,3-didecyl-6-(1-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4] dioxepin-6-yl) pyren-6-yl)-3,4-dihydro-2H-thieno[3,4-b][1,4] dioxepine), P5, which is synthesized by both chemical and electrochemical methods, is highlighted. The polymer shows both electrochromic and fluorescent properties (the emission of yellow (545 nm) and yellowish green light (524 nm) in solid state and in THF solution, respectively). It is noteworthy that P5 has a specific optical band gap (2.2 eV) to reflect the yellow color in the neutral state. Furthermore, the optical and electrochemical features of the polymer were investigated. (C) 2011 Elsevier B. V. All rights reserved.Article Citation - WoS: 26Citation - Scopus: 28A New Electrochromic Copolymer Based on Dithienylpyrrole and Edot(Elsevier Science Bv, 2013) Algi, Melek Pamuk; Oztas, Zahide; Tirkes, Seha; Cihaner, Atilla; Algi, FatihA new compound, namely diethyl 2,5-di(thiophen-2-yl)-1H-pyrrole-3,4-dicarboxylate (1), was copolymerized with 3,4-ethylenedioxythiophene (EDOT) via electrochemical method. The copolymer exhibits multicolor electrochromic property: It is found that the copolymer, poly(1-co-EDOT), has a specific optical band gap (1.71 eV) to reflect and/or transmit reddish brown color in the neutral state, and it can be switched to reddish orange, orange, yellowish green and blue colors upon oxidation in a low switching time (1.0 s). Importantly, these colors are essential for camouflage and/or full color electrochromic device/display applications. In addition to these, the obtained copolymer has a coloration efficiency of 173 cm(2)/C at 500 nm. (C) 2013 Elsevier B.V. All rights reserved.
