Yazar "Ceyhan, A. Abdullah" seçeneğine göre listele

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    Catalytic effect of nickel oxide nanoparticles from Lupinus Albus extract on green synthesis and photocatalytic reduction of methylene blue: kinetics and mechanism
    (Taylor & Francis Inc, 2024) Yilmaz, Mine; Ceyhan, A. Abdullah; Baytar, Orhan
    Green synthesis of nanomaterials is advancing due to their ease of synthesis, cheapness, nontoxicity, and renewability. An environmentally friendly biogenic method has been developed for the green synthesis of nickel oxide nanoparticles (NiO NPs) using phytochemical-rich bioextract. They are rich in bioextract phenolics, flavonoids, and berberine. These phytochemicals successfully reduce and stabilize NiNO3 into NiO NPs. In this study, NiO NPs were synthesized by the green synthesis method from Lupinus Albus. Characterization of NiO NPs was carried out by TEM, XRD, SEM, UV, XRF, BET, and EDX analyses. According to XRD analysis, TEM results also support this, where the NiO NPs particle size diameter is 5 nm. It was determined by the Tauc equation that the band energy gap of NiO NPs is 1.69 eV. It was determined that the BET surface area of NiO NPs was 49.6 m2/g. NiO nanoparticles synthesized from Lupinus Albus extract by the green synthesis method were used as catalysts in the photocatalytic reduction of methylene blue with NaBH4. In the photocatalytic reduction of methylene blue with NaBH4, it was determined that there was no color change in 48 h without a catalyst, and in the presence of NiO nanoparticle catalyst, methylene blue was reduced by 97% in 8 min. The kinetics of the photocatalytic reduction of methylene blue with NaBH4 is a pseudo-first-order kinetic model and the kinetic rate constant is determined as 0.66 min-1, indicating that the catalytic effect of NiO NPs is very high at this value. NiO NPs were used five times in the photocatalytic reduction of methylene blue with NaBH4 and it was determined that the reduction of methylene blue was over 90% in each use. NiO nanoparticles were synthesized from Lupinus Albus extract by green synthesis, which is an easily applied, cost-effective, and environmentally friendly method. The synthesized NiO nanoparticles were characterized using various characterization techniques. NiO nanoparticles have a high catalytic effect in the photocatalytic reduction of methylene blue with NaBH4. Photocatalytic reduction of methylene blue with uncatalyzed NaBH4 could not be achieved, and 97% reduction of methylene blue was completed in 8 min in the presence of NiO nanoparticle catalyst.
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    Design and optimization of production parameters for boric acid crystals with the crystallization process in an MSMPR crystallizer using FBRM® and PVM® technologies
    (Elsevier Science Bv, 2017) Kutluay, Sinan; Sahin, Omer; Ceyhan, A. Abdullah; Izgi, M. Sait
    In crystallization studies, newly developed technologies, such as Focused Beam Reflectance Measurement (FBRM) and Particle Vision and Measurement (PVM) are applied for determining on-line monitoring of a representation of the Chord Length Distribution (CLD) and observe the photographs of crystals respectively; moreover recently they are widely used. Properly installed, the FBRM ensures on-line determination of the CLD, which is statistically associated to the Crystal Size Distribution (CSD). In industrial crystallization, CSD and mean crystal size as well as external habit and internal structure are important characteristics for further use of the crystals. In this paper, the effect of residence time, stirring speed, feeding rate, supersaturation level and the polyelectrolytes such as anionic polyacrylamide (APAM) and non-ionic polyacrylamide (NPAM) on the CLD as well as the shape of boric acid crystals were investigated by using the FBRM G600 and the PVM V819 probes respectively in an MSMPR (Mixed Suspension Mixed Product Removal) crystallizer. The CSD and kinetic data were determined experimentally using continuous MSMPR crystallizer running at steady state. The population density of nuclei, the nucleation rate and the growth rate were determined from the experimental population balance distribution when the steady state was reached. (C) 2017 Published by Elsevier B.V.
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    Production of activated carbon from Elaeagnus angustifolia seeds using H3PO4 activator and methylene blue and malachite green adsorption
    (Taylor & Francis Inc, 2021) Baytar, Orhan; Ceyhan, A. Abdullah; Sahin, Omer
    In this study, activated carbon was obtained from Elaeagnus angustifolia seeds and its usability in the adsorption of methylene blue (MB) and malachite green (MG) from aqueous solution was investigated. Activated carbon was synthesized by chemical activation method using H3PO4 as an activator. In the synthesis of the activated carbon, the effects of various parameters such as the rate of impregnation, duration of activation, temperature of activation and duration of activation were investigated. The characterization of the synthesized activated carbons was carried out by FTIR, SEM and BET analyses and the surface area of the produced activated carbon was determined to be 1,194 m(2) g(-1). The effects of solution initial pH, solution initial concentration and amount of activated carbon on MB and MG adsorption were investigated. The adsorption capacity was found to be higher when the pH of the solution was 8 for MB and 4 for MG. The adsorption kinetics of MB and MG were found to fit the Elovich kinetic model and pseudo-first-order kinetic model, respectively. Adsorption equilibrium data were found to be compatible with Langmuir isotherm for both dyes. According to the Langmuir isotherm, q (max) adsorption capacity was found to be 72 mg/g and 115 mg/g for MB and MG, respectively. Novelty Activated carbon was obtained from Elaeagnus angustifolia seeds and its usability in the adsorption of methylene blue (MB) and malachite green (MG) from aqueous solution was investigated. A high surface area activated carbon was synthesized. The surface area of the produced activated carbon was determined to be 1,194 m(2) g(-1). According to the Langmuir isotherm, q (max) adsorption capacity was found to be 72 mg/g and 115 mg/g for MB and MG, respectively. It has been determined that the adsorption capacity of synthesized activated carbon is high.
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    Utilization of In Situ FBRM and PVM Probes to Analyze the Influences of Monopropylene Glycol and Oleic Acid as Novel Additives on the Properties of Boric Acid Crystals
    (Amer Chemical Soc, 2020) Kutluay, Sinan; Ceyhan, A. Abdullah; Sahin, Omer; Izgi, M. Sait
    The aim of this study was to determine the influences of monopropylene glycol (MPG) and oleic acid (OA) as novel additives on the chord length distribution (CLD) and modification of the shape of boric acid crystals in real time with the use of in situ focused beam reflectance measurement (FBRM) and particle vision and measurement (PVM) probes, which were positioned on a continuous mixed-suspension mixed-product removal (CMSMPR) crystallizer at a steady-state value. In this context, the FBRM probe was used to monitor CLD, which is expressed as the cumulative undersize square-weight percentage distribution of boric acid crystals. CLD is statistically proportional to crystal size distribution. The shapes of the boric acid crystals were viewed in real time with an in situ PVM probe. In addition, a scanning electron microscope (SEM) and an optical microscope were used to characterize the shapes of the boric acid crystals produced in the CMSMPR crystallizer. The chemical structures of the boric acid crystals were characterized by Fourier transform infrared (FT-IR) analysis. The population density of the nuclei, the nucleation rate, and the growth rate of the boric acid crystals were also calculated. As a result, it was proved that industrial problems encountered in the production of boric acid crystals by the crystallization process were eliminated especially in the presence of 100 ppm OA and 50 ppm MPG additives by FBRM, PVM, SEM analysis, and number density theory application. This study revealed novel insights into the modification of the shape of boric acid crystals and into the control of CLD in the presence of OA and MPG using in situ FBRM and PVM probes.