Scopus İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395

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  • Article
    Citation - Scopus: 46
    Willingness to Pay for Renewable Electricity: A Contingent Valuation Study in Turkey
    (Elsevier Inc., 2019-12) Dogan, Eyup; Muhammad, Iftikhar
    Renewable energy sources are advised as an important alternative vehicle for dealing with a high rate of energy dependency and global warming. Turkey has also an ambitious national energy goal of minimizing energy import and producing 30% of electricity from renewable energy sources by 2023. However, it may not be easy to reach these goals. Willingness to Pay (WTP) thus plays a central role in directing appropriate policies for the country to realize its energy targets. This study reviews previous studies in the same literature as well as examines WTP of Turkish citizens for renewable electricity energy by using a stratified-sample and contingent valuation survey of 2500 households. The results from estimated models show that environmental conscience, membership to an environmental organization, age, education level, gender and income of households are significant determinants of WTP. In addition, the mean value of WTP for green electricity by Turkish households is estimated at around US$ 1 (with the exchange rate 5,3 TL/ US$) per month per household. A number of policy suggestions are further discussed. © 2023 Elsevier B.V., All rights reserved.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 10
    The Size and Concentration Effects of Al2O3 Nanoparticles on PSF Membranes With Enhanced Structural Stability and Filtration Performance
    (Desalination Publ, 2017-07) Saki, Seda; Uzal, Nigmet; Ates, Nuray
    Nanocomposite membranes have attracted attention for their high permeability, rejection efficiency, and thermal and mechanical stability. In this study, novel flat-sheet polysulfone nanocomposite membranes were prepared by a phase inversion method with polyethylenimine and Al2O3 nanoparticles to increase the flux and hydrophilicity. Al2O3 nanoparticles were added to the membrane matrix to enhance the permeability, selectivity, and mechanical resistance. Two different sizes of Al2O3 nanoparticles (20 and 80 nm) were used with different weight percentages of 0.2, 1, and 5 wt%. The effects of the size and concentration of the nanoparticles on the structural properties and filtration performance of the membranes were investigated. Scanning electron microscopy, Fourier transform infrared spectroscopy, porosity, water contact angle, thermogravimetric analysis, viscosity, and tensile strength measurements were used to characterize the prepared membranes. The membrane performance was evaluated with water flux and bovine serum albumin rejection tests. According to the results, the membrane containing 15 wt% polysulfone, 1 wt% polyethylenimine, and 5 wt% 20 nm Al2O3 showed the highest pure water flux, porosity, viscosity, and morphological stability. This membrane may have potential uses in water treatment applications.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Simultaneous Low Noise Radio Frequency Tone and Narrow Linewidth Optical Comb Generation From a Regeneratively Mode-Locked Laser
    (SPIE - Society of Photo-Optical Instrumentation Engineers, 2014-10-29) Ozdur, Ibrahim; Ozharar, Sarper; Delfyett, Peter J.
    A regeneratively mode-locked laser with simultaneous low noise radio frequency (RF) tone and optical comb generation is presented. The laser does not need any external RF signal and emits a pulse train at similar to 10 GHz repetition rate with a 1.5-ps optical pulse width after compression. The generated RF tone has a signal-to-noise ratio of 121 dB/Hz and an RF fluctuation of 10(-9) over 0.1 s. The optical frequency comb spacing is also at similar to 10 GHz and the optical comb tooth has a linewidth of <1 kHz. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)
  • Article
    Citation - WoS: 7
    Citation - Scopus: 9
    Robust Tracking Controller for SEPIC Drivers
    (Inst Engineering Technology-IET, 2016-11) Ablay, G.
    The non-minimum phase, non-linear nature of the SEPIC (single-ended primary inductor converter) makes it very difficult to get robust operating conditions under load variations. Sliding-mode control method is utilised to design a robust controller for tracking control of SEPIC converters for various applications. The implementation of the method is illustrated with the use pulse-width modulation comparators in the control loop to preclude the risk of modulator saturation and to ease the operations. The performance of the SEPIC converter is investigated through numerical simulation and analogue electronics implementation to show the validity, robustness and feasibility of the proposed controller.
  • Article
    Citation - WoS: 34
    Citation - Scopus: 41
    Revisiting the Relationship Between Natural Gas Consumption and Economic Growth in Turkey
    (Taylor & Francis inc, 2015-01-12) Dogan, E.
    The objective of this study is to re-analyze the relationship between natural gas consumption (NGC) and economic growth (GR) for Turkey in a multivariate framework by including capital and labor as additional variables because several papers suggest that a bivariate model can suffer from omitted-variables bias. As compared to the findings of Isik (2010), who previously investigated the short-and long-run relationships between GR and NGC using a bivariate model, we find that the magnitude of the coefficient estimate of NGC become substantially smaller in the long-run and the sign of short-run estimate of NGC shift to negative after accounting for capital and labor as well. In addition to that covered by Isik (2010), we investigate the direction of causality between GR and NGC using the vector error correction model Granger causality approach, and reveal the evidence of feedback hypothesis for Turkey.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Rec. 2100 Color Gamut Revelation Using Spectrally Ultranarrow Emitters
    (SPIE - Society of Photo-Optical Instrumentation Engineers, 2017-11-22) Genc, Sinan; Uguz, Mustafa; Yilmaz, Osman; Mutlugun, Evren
    We theoretically simulate the performance of ultranarrow emitters for the first time to achieve record high coverage for the International Telecommunication Union Radiocommunication Sector BT. 2100 (Rec. 2100) and National Television System Committee (NTSC) color gamut. Our results, employing more than 130-m parameter sets, include the investigation into peak emission wavelength and full width at half maximum (FWHM) values for three primaries that show ultranarrow emitters, i.e., nanoplatelets are potentially promising materials to fully cover the Rec. 2100 color gamut. Using ultranarrow emitters having FWHM as low as 6 nm can provide the ability to attain 99.7% coverage area of the Rec. 2100 color gamut as well as increasing the NTSC triangle to 133.7% with full coverage. The parameter set that provides possibility to fully reach Rec. 2100 also has been shown to match with D65 white light by making use of the correct combination of those three primaries. Furthermore, we investigate the effect of the fourth color component on the CIE 1931 color space without sacrificing the achieved coverage percentages. The investigation into the fourth color component, cyan, is shown for the first time to enhance the Rec. 2100 gamut area to 127.7% with 99.9% coverage. The fourth color component also provides an NTSC coverage ratio of 171.5%. The investigation into the potential of emitters with ultranarrow emission bandwidth holds great promise for future display applications. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
  • Article
    Citation - WoS: 17
    Citation - Scopus: 24
    Recovery of Caustic From Mercerizing Wastewaters of a Denim Textile Mill
    (desalination Publ, 2015-03) Varol, Cihangir; Uzal, Nigmet; Dilek, Filiz B.; Kitis, Mehmet; Yetis, Ulku
    The objective of this study was to evaluate caustic recovery from mercerizing wastewater originating from a denim textile producing plant using membrane technology. For this purpose, ultrafiltration (UF) and nanofiltration (NF) processes were considered. In the first stage, in an attempt to control the possible membrane fouling, pretreatment alternatives of flocculation, centrifugation, and microfiltration were evaluated. These pretreatment application alternatives were unsuccessful as they did not provide considerable color and solids removal. In the second stage, UF and NF processes were tested using a tight UF membrane (GR95PP, Alfalaval) and three NF membranes (NP010 and NP030, Microdyn Nadir, and MPF34, Koch Membranes) to accomplish the caustic recovery without applying any pretreatment. The best performance was obtained with NP010 NF in terms of permeate flux along with color and COD rejections. Then, for this membrane the effects of transmembrane pressure (4.03 and 6.23 bar), cross-flow velocity (from 0.40 to 1.40 m/s), and feed temperature (20 and 40 degrees C) were investigated. Temperature positively affected the permeate flux without significant loss in recovery and rejections. Caustic stream produced had about 98-100% of NaOH in the feed at a concentration of 30-40 g/L and therefore was recyclable after a concentration process.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    RF Phase Noise Filtering Properties of an Actively Mode-Locked Laser
    (Wiley, 2018-01-10) Mbonde, Hamidu; Ozharar, Sarper; Ozdur, Ibrahim
    In this article, we are presenting the experimental results and theoretical analysis of radio frequency (RF) phase noise filtering properties of a high Q cavity actively driven mode-locked laser. The experimental results show that, the phase noise of a 10 GHz RF tone can be filtered by at least 10 dB at 200 kHz offset frequency. A theoretical analysis on the limits of phase noise filtering due to the spontaneous emission and the frequency mismatch between the laser cavity modes and the synthesizer frequency is also included.
  • Editorial
    Citation - WoS: 3
    Citation - Scopus: 4
    Precision Medicine in Oncology: Challenges, Stakes and New Paradigms
    (John Libbey Eurotext Ltd, 2019-02) Cox, Stephanie; Rousseau-Tsangaris, Marina; Abou-Zeid, Nancy; Dalle, Stephane; Leurent, Pierre; Cutivet, Arnaud; Denefle, Patrice
  • Article
    Citation - WoS: 6
    Citation - Scopus: 6
    Plasmon Enhanced Emission of Perovskite Quantum Dot Films
    (Cambridge Univ Press, 2018-01-09) Dadi, Seyma; Altintas, Yemliha; Beskazak, Emre; Mutlugun, Evren; Dadl, Seyma; Altlntas, Yemliha
    We propose and demonstrate the photoluminescence enhancement of CsPbBr3 perovskite quantum dot films in the presence of Au nanoparticles. Embedded into a polymer matrix, Au nanoparticle-quantum dot film assemble prepared by an easy spin coating method enabled the photoluminescence enhancement of perovskite quantum dot films up to 78%. The properties of the synthesized perovskite QDs and gold nanoparticles have been analysed using high resolution transmission electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, UV-Vis absorption spectrophotometer, steady state and time-resolved photoluminescence spectrometer.