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Öğe Characteristic properties of adsorbed catalase onto activated carbon based adiyaman lignite(2011) Depci T.; Alkan S.; Kul A.R.; Önal Y.; Alacabey I.; Dişli E.Catalase is one of the most common and important enzymes in biological systems. However, its purification process has some difficulties and it can be easily decomposed in aqueous or nonaqueous solutions. Therefore, a catalase should be adsorbed on solid materials to reduce its inactivation and to increase its economic value. Activated carbon which was obtained from Turkish low-rank coal (Gölbaşi-Adiyaman) by chemical activation was used as a solid carrier to adsorb catalase for the first time in this research. The pore structure of the activated carbon was determined by A Tri Star 3000 (Micromeritics, USA) surface analyzer and scanning electron microscope. In order to determine adsorption properties of catalase, ionic strength effect, temperature-activity, pH-activity, storage stability and operational stability of the activated carbon were investigated. The kinetic and thermodynamic mechanisms of adsorbed enzyme were also studied. The experimental results pointed out that the obtained activated carbon is a viable candidate for an alternative solid carrier for catalase and it may be a promising material for various biotechnological applications. © by PSP.Öğe The effect of regular exercise and massage on oxidant and antioxidant parameters(Association of Physiologists and Pharmacologists of India, 2013) Karabulut A.B.; Emin Kafkas M.; Kafkas A.S.; Önal Y.; Kiran T.R.This experimental study aimed to determine the effects of the combined application of regular exercises and massage on the values of Malondialdehyde (MDA), Nitric Oxide (NOx), Glutathione (GSH), Adenosine Deaminase (ADA) and Superoxide Dismutase (SOD). Twenty five sedentary women (32-50 years) who did not have the habit of getting regularly massages or exercising and participated voluntarily in the study. The subjects were randomly separated into three groups: control group (CG, n=9), exercise group (EG, n=8), and massage and exercise group (MEG, n=8). The basic result of this study was that a statistically significant decrease was observed in the post-test MDA values of both EG and MEG subjects. Moreover, when the GSH and SOD values are compared to CG, a statistically significant increase was determined in the values of both EG and MEG. As a result, the findings show that regular physical activities and massage manipulations significantly decrease MDA, increase SOD and GSH activities, and result in no change in NOx and ADA activities supports the assumption that regular physical activity has positive health effects.Öğe Investigating removal of trimethylxanthine by activated carbon prepared from pet waste(2012) Sanci-Özdemir Ç.; Önal Y.Activated carbon (BK) has been prepared from polymeric wastes by chemical activation with KOH. Adsorption of trimethylxanthine onto BK was investigated with variations of pH, contact time, trimethylxanthine concentration, and temperature. The results were analyzed by the Langmuir and Freundlich equations. Adsorption of trimethylxanthine (caffeine) onto BK follows the Langmuir isotherm model. The kinetics of trimethylxanthine adsorption has been discussed using three kinetic models, i. e., the pseudo first-order, the pseudo second-order, and the intraparticle diffusion models. The kinetic studies showed that the adsorption followed a pseudo second-order reaction. The intraparticle diffusion rate constant, the external mass transfer coefficient, film and pore diffusion coefficients at various temperatures were evaluated. The thermodynamic parameters, such as AG°, AS°, and AH °, have been calculated. The thermodynamics of the trimethylxanthine -BK system indicated an endothermic process. © by PSP.Öğe Reactive Blue 19 Adsorption on Activated Carbon from Pumpkin (Cucurbita Pepo) Seed Waste: Kinetic, Isotherm and Thermodynamic Studies(Kauno Technologijos Universitetas, 2024) Kızıl Y.; Benek V.; Teğin İ.; Önal Y.; Erol K.; Alacabey İ.In this study, the removal of reactive blue 19 dyestuffs in aqueous systems was investigated by the adsorption method using activated carbon obtained from pumpkin seed waste. Activated carbon obtained from pumpkin seed waste functionalized with ZnCl2 was used as an absorbent. Pumpkin seed hydrochar was characterized by FT-IR, SEM, TGA-DTA, BET, and XPS. In the experimental stages, the adsorption equilibrium time was determined as 45 minutes, the adsorbent dosage was 0.8 g and the optimum pH was 6.0. After this step, the adsorption parameters of Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms were investigated. It has been pointed out that the adsorption process fits better with the Freundlich isotherm model, and the adhesion occurs in a multilayered manner and on a heterogeneous surface. Freundlich and Dubinin-Radushkevich isotherms support that the bonding mechanism is realized by physical interactions. When the kinetic data were evaluated, adsorption mechanism was found to be compatible with the pseudo-second-order kinetic model. The thermodynamic parameters of adsorption indicate that the system is endothermic, and the adsorption of reactive blue 19 on activated carbon is a spontaneous process. © 2024, Kauno Technologijos Universitetas. All rights reserved.Öğe Stratigraphic, mineralogic and geochemical characterization of gürün oil shales, central Anatolia, Turkey(2006) Önal M.; Ayyildiz T.; Önal Y.; Akmil-Başar C.A Middle Miocene playa-lake sedimentary sequence containing oil shales and trona is divided into the Gökpinar (the lower oil shale unit) and the Terzio?lu (the upper oil shale unit) Members in the Gürün Basin in eastern Turkey. Thermal decomposition of Gürün oil shales was studied by thermo-gravimetry (TGA), differential thermal analysis (DTA), and Rock Eval pyrolysis. Nu2O content of oil shales reaches 0.2%, SiO2 content reaches 31.5%, and CaO content ranges from 29.8 to 52.7%. Content of Sr, Cu, Zn, Ba and Zr (ppm) exceeds that of other trace elements. In the lower oil shale unit, TOC reaches 9.03 wt%, whereas in the upper oil shale unit, the maximum TOC value is 1.54 wt%, generally being even lower. Oil shale contains mainly calcite, aragonite and montmorillonite minerals. DTA curves of oil shale samples show that exothermic peaks are compatible with TOC values. Weight loss is compatible with chemical properties, DTA results and TGA curves of oil shale. Organic geochemical analyses indicate that Gürün oil shale contains sufficient amounts of kerogen of good quality to generate both oil and gas upon pyrolysis. © 2006 Estonian Academy Publishers.Öğe Studies on removal of naproxen sodium by adsorption onto acf in batch and column(2012) Sarici-Özdemir C.; Önal Y.; Erdo?an S.; Akmil-Başar C.In this study, activated carbon fibers were prepared from textile waste by chemical activation with ZnCl 2 (and coded IPZN1, IPZN2, and IPZN3). After preparation they were characterized by analyses using the BET surface area, FT-IR, and XRD methods. The ability of IPZN1, to remove naproxen sodium from effluent solutions by adsorption was studied. Results were analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich (D-R), Temkin, Frumkin, Halsey and Henderson equations using linearized correlation coefficients at 298 K. The value of Q 0 was determined as 294.11 mg.g -1 and the ?G value of -21.46 kJ.mol -1 for adsorption of naproxen sodium. The fixed-bed adsorption system was used for study of the adsorption of naproxen sodium onto IPZN1. Experiments were conducted to study the effect of flow rate of naproxen sodium. Decreasing the flow rate was found to enhance capacity. The breakthrough data obtained for naproxen sodium was adequately described by the Thomas and Yoon-Nelson adsorption models. This study revealed that ACF is suitable for use as an effective adsorbent for the adsorption of naproxen sodium.Öğe Synthesis, characterization, and adsorption properties of highly microporous structured activated carbon(Turkish Chemical Society, 2021) Küçük İ.; Önal Y.The aim of this study is to synthesize activated carbon with high surface area from peach kernel shells which is an agricultural waste. In this study, activated carbon synthesis was carried out by using CO2 at 2 different temperatures (800 and 900 °C) with physical activation from products carbonized at 4 different temperatures (300, 400, 500, and 600 °C) and 2 different N2 gas flow rates (100 and 500 mL/min). After carbonization, solid, liquid, and gas yields of the materials were calculated. The surface area of activated carbons synthesized was calculated by BET analysis and the differences in the surface area were shown by changing the synthesis conditions. Surface areas vary between 340.15 and 686.74 m2/g. In samples pores formed were examined by DFT plus. It was found that most of these pores consist of micropores. Also, the structures of the samples were examined with SEM and XRD analyses. Methylene blue removal of the synthesized samples was studied and the results were compared. © 2021, Turkish Chemical Society. All rights reserved.
