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Öğe Application of a coating mixture for solid oxide fuel cell interconnects(PERGAMON-ELSEVIER SCIENCE LTD, 2015) Unal, Fatma Aydin; Mat, Mahmut D.; Demir, Ibrahim; Kaplan, Yuksel; Veziroglu, NejatDue to high operating temperature (800-1000 degrees C) of SOFC's, limited number of alloys can be employed for the purpose of current collection. The electrical conductivity of these alloys usually decreases during the operation of SOFC because of highly corrosive cathode (air side) environment. Cr evaporation from such alloys is also an important problem of performance degradation. A spinel Mn1.5Co1.5O4 and perovskite La0.60Sr0.40FeO3 mixture is coated on Crofer alloy for corrosion and chromium protection in the cathode side of a SOFC. In study firstly, the performance of the fuel cell with the Crofer 22 APU as interconnect material was measured up to 100 h without any coating. Secondly, using a screen printing method, bare Crofer 22 APU was coated with Mn1.5Co1.5O4 and finally Mn1.5Co1.5O4 + La0.60Sr0.40FeO3 ceramic powder slurries were employed as the coating material. Then, the performances of a SOFC short stack with interconnects coated by two methods were compared with uncoated interconnect. Results show that uncoated interconnect experienced a significant performance lost from 4.5 W to 3.8 W. On the other hand the cells with screen printing coated with a mixture Mn1.5Co1.5O4 and La0.60Sr0.40FeO3 exhibited decreases only from 5.78 W to 5.42 W in the short-term performance tests. Copyright (c) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.Öğe Subtractive-FTIR spectroscopy to characterize organic matter in lignite samples from different depths(PERGAMON-ELSEVIER SCIENCE LTD, 2012) Gezici, Orhan; Demir, Ibrahim; Demircan, Aydin; Unlu, Nuri; Karaarslan, MuhsinOrganic matter present in lignite samples collected from different depths (i.e. top, mid and bottom) of lignite source. Ilgin, Konya province, was examined by using subtractive-FTIR-ATR spectroscopy. FTIR spectra were recorded on (i) original samples, (ii) the samples dried at 105 degrees C and (iii) the samples acid-treated and dried. After a combustion process performed for each sample at 650 degrees C for 15 min, the spectra of samples were recorded and subtracted from the spectra of untreated samples. Hence, a software-based subtraction made it possible to acquire a representative spectra related with organic matter. As the contribution of the bands related with inorganic constituents in lignite samples were eliminated after spectrum-subtraction procedure, difference-spectra led analyzing the spectra related with organic matter in lignite samples, reasonably. Furthermore, the bands related with acidic functional groups, aromatic and aliphatic structures were analyzed on the basis of difference-spectra, easily. From the difference-spectra it was shown that an acid-treatment process under mild conditions caused shift in some specific bands related with carbonyl groups of carboxyls so that the band at around 1710 cm(-1) arisen, while the intensity of the band at around 1420 cm(-1) was diminished. Through the acid-treatment process, acidic groups in lignite samples from different depths were thought to be turned into similar forms by protonation and/or stripping of metal ions originally bonded. Difference-spectra acquired for acid-treated samples made it possible to evaluate the form of carboxylic acid groups present in the studied samples under specific environmental conditions. Hence, a facile and environmentally-friendly methodology was used to analyze organic matter in lignite by using FTIR spectra, and valuable information was acquired about the aliphatic, aromatic and acidic character of the studied lignite samples collected from different depths. The proposed methodology seems to be promising in acquiring approximate representative spectra for lignite organic matter by using little or no chemicals. (C) 2012 Elsevier B.V. All rights reserved.Öğe Synthesis and characteristics of N-(glyoxyldioxime)-N '-(2-hydroxybenzylidene)-1,4-diaminonaphthalene and its metal complexes(MAIK NAUKA/INTERPERIODICA/SPRINGER, 2008) Kaya, Muharrem; Yenikaya, Cengiz; Demir, Ibrahim; Kalfa, Orhan MuratA new vic-dioxime, N-(glyoxyldioxime)-N'-(2-hydroxybenzylidene)-1,4-diaminonaphthalene, was synthesized proceeding from naphthalene. Its complexes of nickel, copper and cobalt were prepared. The vic-dioxime and its complexes were charecterized by FT-IR, UV, H-1 NMR, mass spectrometry, elemental analysis, DTA/TG analysis techniques and conductometric measurements.Öğe Synthesis and characterization of a novel iminooxime Schiff base ligand and its complexation with copper(II), nickel(II), zinc(II), cadmium(II), and cobalt(II)(SLOVENSKO KEMIJSKO DRUSTVO, 2008) Demir, Ibrahim; Bayrakci, Mevluet; Mutlu, Kuersat; Pekacar, A. IhsanIn this study, a novel iminooxime ligand having dimetoxide groups as well as its complexes with copper(II), nickel(II), zinc(II), cadmium(II), and cobalt(II) were synthesized. We have used 3,4-dimetoxyacetophenone as starting material, and synthesized isonitroso-3,4-dimetoxyacetophenone by reaction of 3,4-dimetoxyacetophenone with n-butyl nitrite in presence of sodium ethoxide. 3-hydroxyphenylimino-isonitroso-3,4-dimetoxyacetophenone(3) was obtained from reaction of such nitroso compound with 3-aminophenol and its complexes were prepared by treatment of iminooxime with metal salts as Cu(II), Ni(II), Zn(II), Cd(II), and Co(II) in methanol, respectively. All of the structures were characterized by using spectroscopic techniques.Öğe Synthesis and characterization of complexes of vic-dioxime derivatives with transition metal(ASIAN JOURNAL OF CHEMISTRY, 2008) Kaya, Muharrem; Demir, Ibrahim; Yenikaya, CengizA novel vic-dioxime compound (H(2)L) and their transition metal complexes were synthesized for the first time. This compound, N-[(4-(2,4-dihyroxybenzylideneamino)naphthalen-1-yl)]-N'-hydroxy-2-(hydroxyimino)acetimidamide, have been synthesized by starting metarial of naphthalene. The complexes of nickel(II), copper(II) and cobalt(II) with H2L were prepared. The ligand and its metal complexes were charecterized FT-IR, UV, (1)H NMR, (13)C NMR, MS, elemental analysis and conductometric measurements.Öğe Synthesis and characterization of Cu(II), Cd(II) and Hg(II) complexes with Schiff bases(ASIAN JOURNAL OF CHEMISTRY, 2007) Demir, Ibrahim; Akkaya, Mustafa; Bayrakci, Mevlut; Pekacar, A. IhsanTwo new Schiff base have been synthesized by the condensation 1,2-diaminoethane (HL) and 1,4-diamino butane (HL) with isonitroso-p-chloroasetafenon. The complexes of copper(II), cadmium(II) and mercury(II) with HL and HL were prepared. The ligands and their metal complexes were characterized by spectroscopic techniques.Öğe Synthesis and characterization of transition metal complexes of oxime(ASIAN JOURNAL OF CHEMISTRY, 2007) Demir, Ibrahim; Pekacar, A. IhsanIn this study a novel oxime, isonitroso-p-methoxyacetophenone was synthesized. A new schiff base have been synthesized by the condensation 1,2-diaminoethane (HL) with isonitroso-p-methoxyacetophenone. The complexes of nickel(II), copper(II), cobalt(II), zine(II), cadmium(II) and mercury(II) with HL were prepared. The ligand and their complexes were charecterized by spectroscopic techniques.Öğe Synthesis, Characterization, and Spectroscopic Properties of a Symmetrical Schiff Base Ligand and its Bimetallic Complexes(TAYLOR & FRANCIS INC, 2011) Bayrakci, Mevlut; Ertul, Seref; Bas, Salih Zeki; Demir, IbrahimThis article presents the synthesis of new Schiff base ligand and preparation of its transition metal complexes with copper (II), nickel (II), zinc (II), and cobalt (II). Furthermore, absorption and fluorescence properties of ligand and its metal complexes are investigated. The effect of the solvents, such as N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethanol, methanol, 1,4-dioxane on fluorescence properties of metal complexes, are performed and obtained results are summarized. All of the structures were characterized by using spectroscopic techniques.Öğe Synthesis, electrochemical, and antibacterial activity of some novel N(4)O(2) ligand derivativies(MAIK NAUKA/INTERPERIODICA/SPRINGER, 2008) Demir, Ibrahim; Sahmetlioglu, Ertugrul; Celik, Gokcen Y.; Unal, MuratA novel ligand has been synthesized by the condensation of 1,3-diaminoprophane (HL) with isonitroso-p-chloroacetophenone. The complexes of cobalt(II), nicel(II), cupper(II) and zinc(II) with HL were prepared. All compounds were characterized by spectroscopic techniques and its antibacterial activities were determined by the disc diffusion method used against to those gram-positive and-negative bacteria. All compounds were investigated by cyclic voltammetry at 25 degrees C. The voltammograms were recorded with a potential scan of 100 mV s(-1).Öğe tert-butyl 3a-chloroperhydro-2,6a-epoxyoxireno[e]isoindole-5-carboxylate(INT UNION CRYSTALLOGRAPHY, 2007) Kosar, Basak; Karaarslan, Muhsin; Demir, Ibrahim; Bueyuekguengoer, OrhanIn the title compound, C13H18ClNO4, the molecules are linked only by weak van der Waals interactions. The boat form of the six-membered ring is almost symmetric with respect to the epoxy bridge. The three five-membered rings adopt envelope conformations.
