1,720,963 research outputs found
Novel electrochromic copolymers based on 3-3′-dibromo-2-2′-bithiophene and 3,4 ethylene dioxythiophene
No full textA novel electrochromic material of poly(3-3?-dibromo-2-2?-bithiophene) (P(DBT)) and new electrochromic copolymers of 3,4-ethylenedioxythiophene and 3-3?-dibromo-2-2?-bithiophene prepared from different monomer feed ratios were synthesized by using electroanalytical methods. Homopolymerization and copolymerization were achieved in the medium of 0.1 M LiClO4/ACN solvent-electrolyte couple. Cyclic voltammetry (CV), atomic force microscopy (AFM), fourier transform infrared spectroscopy and ultraviolet and visible (UV-Vis) absorption spectroscopy were used to characterize corresponding homopolymer and copolymers. Electrochemical, morphological and optical properties of copolymers were alternated depending on changing the monomer feed ratio in the copolymer structure. Furthermore, electrochromic properties of the all polymers were also investigated. © 2017 Elsevier Lt
Poly(3,4-ethylenedioxythiophene) electrode grown in the presence of ionic liquid and its symmetrical electrochemical supercapacitor application
Get PDFWOS:000427373000014Poly(3,4-ethylenedioxythiophene) polymer film (PEDOT-IL) was electrosynthesized in the ionic liquid (IL) 1-ethyl-3-methylimidazolium hydrogen sulphate (EMIMHSO4) medium, which also contains 0.1 M LiClO4 in ACN. For comparison reasons in terms of structure and electrode capacitance performance, PEDOT film was also synthesized electrochemically without IL. The SEM results show that PEDOT-IL film has more porous surface and fine textures with nanometer-diameter than PEDOT polymer. Different electrochemical methods including galvanostatic charge-discharge (CD) experiments, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were carried out to investigate the applicability of the system as a redox supercapacitor for both polymers. PEDOT-IL electrode shows higher optimum specific capacitance than PEDOT film. Additionally, the symmetrical supercapacitor was assembled from two PEDOT-IL electrodes in LiClO4/ACN medium and exhibited a maximum specific capacitance of 107 F g(-1), an energy density of 11.5 Wh kg(-1) at a power density 13 kW kg(-1), and an excellent cycle life of 96% specific capacitance retention after 1000 cycles.Karamanoglu Mehmetbey UniversityKaramanoglu Mehmetbey University [KMU-BAP-38-M-16]We gratefully acknowledge financial support from Karamanoglu Mehmetbey University (KMU-BAP-38-M-16)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
An investigation on electrochromic properties of new copolymers based on dithienylpyrrole and propylenedioxythiophene
No full textWOS:000418984300014In this research, the effect of ProDOT (3,4-propylenedioxythiophene) monomer on the electrochromic properties of dithienylpyrrole type copolymer has been studied. The copolymers of these two components have obtained by electroanalytical methods in different monomer ratios. The morphological, optical and electrochemical characterizations of all copolymers were investigated. The electrochromic properties of the novel films were investigated by cyclic voltammetry and spectroelectrochemical methods. Different colors of the electrochromic films were achieved under different applied potentials. The maximum difference of the UV-vis absorption of the film was found about 42% between -0.6 V and 1.2 Vat 850 nm for P(C3) copolymer with a fast switching time (0.4 s). The morphological and chemical analyses for copolymers were also detected.Karamanoglu Mehmetbey UniversityKaramanoglu Mehmetbey UniversityThe author gratefully acknowledges the financial support from Karamanoglu Mehmetbey University. Authors thanks to Dr. Arif Kivrak for his help during the synthesis of the molecules. The preliminary studies of this manuscript was presented at International Congress of the New Approaches and Technologies for Sustainable Development on September, 21-24, 2017 in Turkey
Synthesis and characterization of a new poly(dithieno ( 3,2-b: 2 ', 3 '-d) pyrrole) derivative conjugated polymer: Its electrochromic and biosensing applications
Get PDFWOS:000418581800006Synthesis and electropolymerization of a new conjugated dithieno(3,2-b: 2',3'-d) pyrole (DTP) derivative, namely, 2-(2-(2-(4H-dithieno[3,2-b: 2',3'-d] pyrrol-4-yl) ethoxy) ethoxy) ethanamine, (DTP-alkoxy-NH2) monomer are presented. The electrochemical, spectroelectrochemical effects and biosensor capability towards to glucose oxidase enzyme of P(DTP-alkoxy-NH2) polymer film are investigated in detail during the placement of alkoxy-NH2 functional unit in the polymer. Electrochemical and optical results between neutral and oxidized states of the polymer film show that (P(DTP-alkoxy-NH2)) has reversibly multi-electrochromic behaviors. Furthermore, glucose oxidase enzyme (GOx) is covalently immobilized on Au electrodes modified with P(DTP-alkoxy-NH2) conducting polymer. This enzyme is entrapped into conducting polymer during electropolymerization of DTP monomer on the electrodes. Some characterization parameters (Maximum reaction rate, Michaelis-Menten constants, temperature, pH and operational stabilities) for this kind of biosensor application is also determined. (C) 2017 Elsevier Ltd. All rights reserved.Karamanoglu Mehmetbey UniversityKaramanoglu Mehmetbey University [06-M-15]The author gratefully acknowledges the financial support from Karamanoglu Mehmetbey University (Grant No: 06-M-15)
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
An effective approach for high-efficiency photoelectrochemical solar cells by using bifunctional DNA molecules modified photoanode
No full textWOS:000390118300022This paper firstly reports the effect of deoxyribonucleic acid ( DNA) molecules extracted from chickpea and wheat plants on the injection/recombination of photogenerated electrons and sensitizing ability of dye-sensitized solar cells (DSSCs). These high-yield DNA molecules are applied as both linker bridging unit as well as thin tunneling barrier (TTB) at titanium dioxide (TiO2)/dye interface, to build up high-efficient DSSCs. With its favorable energy levels, effective linker bridging role, and double helix structure, bifunctional DNA modifier shows an efficient electron injection, suppressed charge recombination, longer electron lifetime, and higher light harvesting efficiency, which leads to higher photovoltaic performance. In particular, a photoconversion efficiency (PCE) of 9.23% is achieved by the binary chickpea and wheat DNA-modified TiO2 (CW@TiO2) photoanode. Furthermore, time-resolved fluorescence spectroscopy measurements confirm a better electron transfer kinetics for DNA-modified TiO2 photoanodes, implying a higher electron transfer rate (k(ET)). This work highlights a great contribution for the photoanodes that are linked with DNA molecule, which act as both bridging unit and TTB to control the charge recombination and injection dynamics, and hence, boost the photovoltaic performance in the DSSCs.Scientific Research Commission of Karamanoglu Mehmetbey UniversityKaramanoglu Mehmetbey University [03-YL-14]The authors would like to express their thanks to Dr. Sabriye Acikgoz and Dr. Buket Bezgin Carbas for providing the time-resolved fluorescence lifetime measurements of photoanodes and cyclic voltammogram measurements of DNA molecules, respectively. Furthermore, this work was financially supported by the Scientific Research Commission of Karamanoglu Mehmetbey University under Project No. 03-YL-14
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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