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Erdem A.,C anakkale Onsekiz Mart University | Erdem A.,University of Science and Arts of Iran | O zturk O.,C anakkale Onsekiz Mart University | O zturk O.,University of Science and Arts of Iran
Monthly Notices of the Royal Astronomical Society | Year: 2014

We applied a revised model for non-conservative mass transfer in semi-detached binaries to 18 Algol-type binaries showing orbital period increase or decrease in their parabolic O-C diagrams. The combined effect of mass transfer and magnetic braking due to stellar wind was considered when interpreting the orbital period changes of these 18 Algols. Mass transfer was found to be the dominant mechanism for the increase in orbital period of 10 Algols (AM Aur, RX Cas, DK Peg, RV Per, WX Sgr, RZ Sct, BS Sct, W Ser, BD Vir, XZ Vul) while magnetic braking appears to be the responsible mechanism for the decrease in that of 8 Algols (FK Aql, S Cnc, RU Cnc, TU Cnc, SX Cas, TW Cas, V548 Cyg, RY Gem). The peculiar behaviour of orbital period changes in three W Ser-type binary systems (W Ser, itself a prototype, RX Cas and SX Cas) is discussed. The empirical linear relation between orbital period (P) and its rate of change (dP/dt) was also revised. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Merve Icli,Middle East Technical University | Pamuk M.,C anakkale Onsekiz Mart University | Algi F.,C anakkale Onsekiz Mart University | Onal A.M.,Middle East Technical University | Cihaner A.,Atilim University
Chemistry of Materials | Year: 2010

To demonstrate the effect of donor (D) and acceptor (A) units on the structure-property relationships of electrochromic polymers, design, synthesis, characterization and polymerization of a series of D-A type systems, 1-5, based on thiophene, 3,4-ethylenedioxythiophene, and 3,3- didecyl-3,4-dihydro-2H- thieno[3,4-b][1,4]dioxepine as D units and 2,1,3-benzoselenadiazole, 2,1,3- benzothiadiazole and 2-decyl-2H-benzo[d][1,2,3]triazole as A units are highlighted. It is found that these units play key roles on the redox behavior, band gap, neutral state color, and the electrochromic performance (stability, optical contrast, coloration efficiency, and switching time) of the system. It is noted that electropolymerization of these D-A systems provides processable low band gap electrochromes, P1-P5, exhibiting high redox stability, coloration efficiency, transmittance and/or contrast ratio and low response time. Furthermore, P1-P5 reflect various hues of blue and green pallets of the RGB color-space in the neutral state. In particular, it is noteworthy that P5 is an excellent blue-to-colorless polymeric electrochrome, which, to our best knowledge, exhibits the highest optical contrast and coloration efficiency among the D-A type systems. The panoramic breadth of the neutral state colors and intriguing features of these polymeric materials further confirm that D-A approach allows engineering tunable electrochromes, which hold promise for commercialization of polymeric RGB electrochromics. © 2010 American Chemical Society.

Kizil U.,C anakkale Onsekiz Mart University | Tisor L.,North Dakota State University
Journal of Earth System Science | Year: 2011

Accuracies of Real-Time Kinematic Global Positioning (RTK-GPS) system and Total Station (TS) were investigated in GIS environment. In geostatistical evaluations, Kriging method was used with spherical, exponential, and Gaussian models. The survey results demonstrated that an area of 3.5 ha or smaller can be best explained with Gaussian model, while the larger areas require a spherical model. A vertical error of 60 cm and a horizontal error of 30 cm can be observed when the survey points outside the construction area are eliminated. The optimum area per survey point was calculated to be 20×20 m 2 to increase the accuracy. This case study showed that an inaccurate survey can result cost over estimations up to 27%. © Indian Academy of Sciences.

Outcu M.,C anakkale Onsekiz Mart University | Arifolu N.,C anakkale Onsekiz Mart University | Yilmaz E.,C anakkale Onsekiz Mart University
JAOCS, Journal of the American Oil Chemists' Society | Year: 2015

Virgin olive oil and beeswax were used to prepare four oleogel emulsions (EM1-EM4) through simultaneous oleogelation emulsification, and these oleogels were compared with breakfast margarine (BM). The melting temperatures of the oleogel emulsions ranged from 52.29 to 57.52°C, while it was 40.36°C for the BM sample. Similarly, the solid fat content (SFC) of the oleogel emulsions was between 3.57 and 3.68% at 20°C, and that of BM was 7.70%. Except the EM3 sample, all oleogel emulsions exhibited mechanical stability. The firmness and stickiness values of the oleogel emulsion samples were lower than those of the BM sample, but they remained almost constant through 90 days of storage. Furthermore, the fine water droplets and needle-like beeswax crystals within the continuous oil phase were stable during the storage. The X-ray diffraction patterns of the samples revealed that the oleogel emulsions contain crystals similar to β′ polymorphs, characterized by a homogenous, smooth and fine texture. The presence of inter and intramolecular hydrogen bonds was proved by Fourier Transform Infrared (FT-IR) measurements. The developed oleogel emulsions were found to be stable in terms of texture, color and oxidation during 90 days of storage. In conclusion, these oleogel emulsion products can be used as margarine/spread stocks. © AOCS 2015.

Dayan O.,C anakkale Onsekiz Mart University | Yunus Inan M.,C anakkale Onsekiz Mart University
Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry | Year: 2015

Ru(II) complexes with the general formula [RuCl2(p-cymene)(L1-3)], K1-3, (L1-3: monodentate benzimidazole ligands), [RuCl2(L5-6)(S)], K4-7, (L5-6: tridentate benzimidazole ligands, S: Solvents [methanol or acetonitrile]), and [RuCl2(L5)(L1-2)], K8-9, were synthesized from [RuCl2(p-cymene)]2 dimer and mono- and tridentate benzimidazole ligands. The compounds were characterized by elemental analysis, IR, UV-Vis, and NMR. The synthesized Ru(II) complexes (K1-9) were tested as catalysts for the transfer hydrogenation (TH) of acetophenone to secondary alcohols in the presence of KOH using 2-propanol as a hydrogen source at 82°C. All complexes were active catalysts for TH of acetophenone with good yields under mild conditions (after 60 minutes, yields of up to 97%). Copyright © Taylor & Francis Group, LLC.

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