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Öğe A comparison of different activated carbon performances on catalytic ozonation of a model azo reactive dye(Iwa Publishing, 2012) Gul, S.; Eren, O.; Kir, S.; Onal, Y.The objective of this study is to compare the performances of catalytic ozonation processes of two activated carbons prepared from olive stone (ACOS) and apricot stone (ACAS) with commercial ones (granular activated carbon-GAC and powder activated carbon-PAC) in degradation of reactive azo dye (Reactive Red 195). The optimum conditions (solution pH and amount of catalyst) were investigated by using absorbencies at 532, 220 and 280 nm wavelengths. Pore properties of the activated carbon (AC) such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by N-2 adsorption. The highest BET surface area carbon (1,275 m(2)/g) was obtained from ACOS with a particle size of 2.29 nm. After 2 min of catalytic ozonation, decolorization performances of ACOS and ACAS (90.4 and 91.3%, respectively) were better than that of GAC and PAC (84.6 and 81.2%, respectively). Experimental results showed that production of porous ACs with high surface area from olive and apricot stones is feasible in Turkey.Öğe Evaluation of the effects of ozone therapy on Escherichia coli-induced cytitis in rat(Springer London Ltd, 2013) Tasdemir, C.; Tasdemir, S.; Vardi, N.; Ates, B.; Onal, Y.; Erdogan, S.; Yucel, A.The aim of the study was to investigate the effect of ozone on oxidative/nitrosative stress and bladder injury caused by Escherichia coli in rat bladder. Twenty-one Wistar-Albino-type female rats included in the study were divided into three groups of equal number: (1) sham operation (control), (2) E. coli-only (EC), (3) EC + ozone. After ozone therapy for 3 days, urine and tissue samples were obtained for biochemical, microbiological, and histopathological analysis. Tissue malondialdehyde (MDA), myeloperoxidase (MPO), and nitric oxide (NO) level were increased, whereas superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity was decreased in the EC group. MDA, MPO, and NO levels were decreased, whereas SOD, GPx activity was increased in the ozone-treated group. Also, there was no bacterial translocation in this group. The results of the present study suggest that ozone may be used as an agent to protect the bladder from oxidative/nitrosative stress occurring in cystitis.Öğe How safe is the use of herbal weight-loss products sold over the Internet?(Sage Publications Ltd, 2013) Ozdemir, B.; Sahin, I.; Kapucu, H.; Celbis, O.; Karakoc, Y.; Erdogan, S.; Onal, Y.Background: In recent years, the use of herbal weight-loss products sold over the Internet has rapidly increased; however, the safety of these products has not been well documented yet. More importantly, the declared ingredients in these products could be different than the marketed contents. Methods: Nine different herbal weight-loss products sold over the Internet were obtained. The ingredients of each product were analyzed in the Laboratory of Forensic Medicine and the Scientific and Technological Research Laboratory of Inonu University. Results: Although all studied weight-loss products were presented as pure herbal, three of them contain sibutramine, three contain caffeine, and three contain caffeine + temazepam. The amount of sibutramine in each capsule was found to be over 10 mg. We analyzed toxic and trace element levels of nine herbal products and found that these herbal products, even in low amounts, contain Pb, Al, Ni, and Ba. Conclusions: Our results indicate that herbal weight-loss products available without prescription and claimed to be purely herbal may contain pharmaceutical substances like sibutramine or temazepam in high doses. Moreover, they also may become contaminated with toxic metals. Since people commonly use these products unaware of its real constituents and without the suggestion or control of a physician, they might cause various health problems some of which might be harmful. Strict legal rules and control mechanisms must be established to minimize their possible harmful effects.Öğe Nano-sized Spherical MgB2 Superconducting Powder Fabrication Using MHz Range Ultrasonic Spray Pyrolysis (USP) System(Springer, 2011) Yakinci, M. E.; Aksan, M. A.; Balci, Y.; Altin, S.; Onal, Y.; Aydogdu, Y.We have fabricated 40-150 nm sized MgB2 superconducting spherical powders by using a 2.4 MHz ultrasonic spray pyrolysis system and consecutive high temperature heating and powder collection chamber. Various chemical solutions, which contain Mg, B, de-ionized water, acetone and LAPSA in different concentrations and gas atmosphere, were used to obtain MgB2 superconducting powders. Microstructural, transport and magnetic characterizations of the powders were performed using XRD, SEM-EDX, R-T, M-H analysis and critical current density calculations, which is found in the range of 10(6) Acm(-2), indicating improved flux pinning properties.Öğe Organic geochemical characterization and mineralogic properties of Mengen oil shale (Lutetian), Bolu-Turkey(Estonian Acad Publishers, 2008) Senguler, I.; Ayyildiz, T.; Onal, Y.; Onal, M.Mengen (Bolu) basin extending northeast-southwest contains Neogene limestone, claystone, marl, lignite, and oil shale sequences. Oil shale deposit has been accumulated in shallow restricted back-platform basins during the Middle Eocene. The Middle Eocene (Lutetian) deposit divides into seven levels L1-7. Level L-6 consists of oil shale (thickness ranging from few mm to 4 meters), marl, claystone and siltstone intercalations. Investigated oil shale strata of an average 50-cm thickness are green or dark brown in color. Oil shale samples contain mainly quartz, calcite, ankerite, chabazite and smectite minerals. FTIR spectra and exothermic maximum and minimum peaks of DTA and TGA weight-loss curves of oil shale samples are compatible with TOC values and mineral composition, respectively. Total organic carbon (TOC) and genetic potential (GP) values of the oil shale samples are between 1.13 and 28.32 wt.% and 176.11 and 281.22 mg HC/g rock, respectively. Hydrogen index (HI) and T-max values range from 497 to 968 mg HC/g rock and 430 to 442 degrees C, respectively. TOC and GP values indicate a good source rock potential of this oil shale, and T-max values show its general immaturity. The samples stand mainly between types I and II of the evaluation path but closer to type I. This type of organic matter can generate oil upon pyrolysis.Öğe Removal of lead ions by acid activated and manganese oxide-coated bentonite(Elsevier, 2009) Eren, E.; Afsin, B.; Onal, Y.This paper presents the adsorption of Pb(II) from aqua solutions onto Unye (Turkey) bentonite in raw (RB), acid activated (AAB) and manganese oxide-coated (MCB) forms. Adsorption of Pb(H) by RB, AAB and MCB sample was investigated as a function of the initial Pb(II) concentration, solution pH, ionic strength, temperature and inorganic ligand (Cl-). Changes in the surfaces and structure were characterized by means of XRD, IR and potentiometric titration. The Langmuir monolayer adsorption capacities of RB, AAB and MCB in 0.1 M KNO3 solution were estimated as 16.70, 8.92 and 58.88 mg/g, respectively. The spontaneity of the adsorption process is established by decrease in Delta G which varied from -21.60 to -28.60kJ/mol (RB), -22.63 to -29.98 kJ/moI (AAB) and -19.57 to -26.22 (MCB) in temperature range 303-338 K. (C) 2008 Elsevier B.V. All rights reserved.Öğe Stratigraphic, mineralogic and geochemical characterization of Gurun oil shales, Central Anatolia, Turkey(Estonian Acad Publishers, 2006) Onal, M.; Ayyildiz, T.; Onal, Y.; Akmil-Basar, C.A Middle Miocene playa-lake sedimentary sequence containing oil shales and trona is divided into the Gokpinar (the lower oil shale unit) and the Terzioglu (the upper oil shale unit) Members in the Gurun Basin in eastern Turkey. Thermal decomposition of Gurun oil shales was studied by thermo-gravimetry (TGA), differential thermal analysis (DTA), and Rock Eval pyrolysis. Na2O 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 Gurun oil shale contains sufficient amounts of kerogen of good quality to generate both oil and gas upon pyrolysis.
