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    Book Part
    Citation - Scopus: 2
    Green Energy Generation Using Membrane Technologies Based on Salinity Gradient
    (Elsevier, 2023) Güler,E.; Cihanoğlu,A.; Altıok,E.; Kaya,T.Z.; Eti,M.; Kabay,N.
    Electrical energy can be extracted from salinity gradients, often represented by two aqueous solutions with different salinities. This becomes very interesting when sustainable and practical electromembrane processes can be applied to convert the salinity gradient power into electric power. Reverse electrodialysis (RED), in this context, has gained much interest in the last few years. In addition to many operational and design parameters affecting the process output, ion exchange membranes (IEMs) represent core elements in RED. In this chapter, it is aimed to introduce and discuss the current trend of IEMs as well as vital operational parameters and fouling affecting the RED performance. © 2023 Elsevier Inc. All rights reserved.
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    Article
    Citation - WoS: 8
    Effect of H2o Ratio on Photocatalytic Activity of Sol-Gel Tio2 Powder
    (Ice Publishing, 2013) Agartan, Lutfi; Kapusuz, Derya; Park, Jongee; Ozturk, Abdullah
    Effect of water/tetraethyl orthotitanate molar ratio (R) on the formation and morphology of sol-gel-derived titania powder has been studied. Solutions for R of 3 and 5 have been prepared. Initial viscosity of the solutions and viscosity of the gels prepared by aging the solutions for some time were measured. Results revealed that lower gel viscosities lead to better crystallization of the aerogel. Aerogels were dried at 80 degrees C for 24 h and then calcined at 300 degrees C for 1 h to obtain titania powders. The structural and morphological analyses of the powders were performed using X-ray diffraction and scanning electron microscopic characterization techniques. Titania particles obtained after calcination composed of only anatase phase and were in the size range of 9-50 nm. The photocatalytic activity of the powders was evaluated in terms of the degradation of methylene blue (MB) solution under UV (ultraviolet) illumination. A diffuse reflectance spectroscopy was used for the band gap energy measurements. Results revealed that R had a profound effect on the particle morphology and photocatalytic activity of sol-gel-derived titania powders. The titania powders prepared from the solution for R of 5 degraded 99.47% of MB solution under UV illumination in 90 min.
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    Article
    Citation - WoS: 1
    Deposition and Characterization of ZnSnSe2 Thin-Films Deposited by Using Sintered Stoichiometric Powder
    (Gazi Univ, 2019) Bayrakli Surucu, Ozge; Gullu, Hasan Huseyin
    In this work, ZnSnSe2 (ZTSe) thin films were deposited using crystalline powder grown by vertical Bridgman-Stockbarger technique. The deposition process was carried out by means of e-beam evaporation on the well-cleaned soda lime glass substrates and keeping them at the substrate temperature of 200 degrees C. The structural, optical and electrical properties of ternary ZTSe thin films were investigated depending on the annealing temperature at 250 and 300 degrees C. X-ray diffraction analysis showed that as-grown films were in amorphous structure, however annealing at 250 degrees C triggered the crystallization on the preferred ternary structure and annealing at 300 degrees C resulted in the changes from amorphous to the polycrystalline structure. Using the compositional analysis, the detail information about the stoichiometry and the segregation mechanisms of the constituent elements in the structure were determined for both as-grown and annealed samples. In addition, they were morphologically characterized using scanning electron microscopy technique. The electrical properties were analyzed using temperature dependent dark- and photo-conductivity measurements. From the variation of electrical conductivity as a function of the ambient temperature, the current transport mechanisms and corresponding activation energies at specific temperature intervals for each sample were determined. The optical properties for the ZTSe thin films were studied depending on the structural changes with annealing.