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21.
Aysel Kantürk Figen Osman İsmail Sabriye Pişkin 《Journal of Thermal Analysis and Calorimetry》2012,107(3):1177-1189
Devolatilization behavior of several types of agricultural stalks (sunflower, rice, corn, and wheat) was studied using thermogravimetric
system (TG) under nitrogen atmosphere at different heating rates (10, 15, and 20 °C min-1). Coats&Redfern, Horowitz&Metzger, and Arrhenius non-isothermal kinetic models were applied to calculate the devolatilization
kinetic parameters and the devolatilization rate equations have been established. In addition, the kinetic compensation effect
(KCE) has also been used to correlate pre-exponential factor (k
o) with activation energy (E
a) and an existence of the KCE is accepted. TG-FT/IR analyses were applied of the different stalks and FT/IR stack plot used
to analyze the devolatilization gas products (CO2, CH4, HCOOH, CH3OH). Infrared vibrational frequencies, micro structure and crystallinity of stalks were investigated by Fourier transform
infrared spectroscopy (FT/IR), scanning electron microscope (SEM), and X-ray diffraction analysis (XRD), respectively. 相似文献
22.
Hakan Alp Zekeriya Biyiklioğlu Gülsev Dilber ÜmmÜhan Ocak Aysel Marap Halit Kantekin 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(3-4):283-288
Synthetic procedures for new N2S4- and N2S5-donor macrocycles (2 and 4) were given. The ligands were prepared by the reaction of NaBH4 with the appropriate macrocyclic diamide in the presence of boron trifluoride ethyl etherate in dry tetrahydrofuran (THF).
Solvent extraction method was used to evaluate metal-ion binding properties of the new ligands. The solvent extraction experiments
suggested that the reduced macrocycles have Ag+ and Hg2+ selectivities compared to Pb2+, Co2+, Zn2+, Ni2+, Cu2+, Mn2+ and Cd2+ ions. The extraction constants (log K
ex) and complex compositions were determined for Ag+ and Hg2+ complex of compound (4). 相似文献
23.
Antimicrobial effects of bis(Δ2-2-imidazolinyl)-5,5′-dioxime and its mono- and tri-nuclear complexes
Uğur Aysel Mercimek Bedrettin Özler M. Ali Şahin Nurettin 《Transition Metal Chemistry》2000,25(4):421-425
Bis(Δ2-2-imidazolinyl)-5,5′-dioxime (H2L) and its nickel, cobalt, zinc, cadmium and mercury complexes have been prepared and tested in vitro against different microorganisms in order to assess their antimicrobial properties. We used Bacillus subtilis RSKK 244, Micrococcus flavus, Streptococcus faecalis RSKK 500, Staphylococcus aureus RSKK 490 from Gram-positive bacteria; Pseudomonas aeruginosa RSKK 356, Salmonella typhimurium RSKK 1017, Escherichia coli RSKK 550, Enterobacter aerogenes RSKK 720 from Gram-negative bacteria, Candida tropicalis RSKK 665 and Penicillium raciborskii IMI 40568.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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25.
Aysel Kantürk Figen Ay?e ?ztürk Sabriye Pi?kin 《Research on Chemical Intermediates》2012,38(9):2343-2354
The presence of caustic soda in the spent sodium borohydride (NaBH4) fuel in high concentrations creates environmental problems associated with the transportation and the disposal of the fuel, orits recycling into NaBH4. It is clear that the high level of caustic soda in the spent fuel requires efficient and proper formulation of its industrial recycling applications. The present study regards the conversion process of the caustic soda present in high concentrations in spent NaBH4 fuels. Properties of the caustic used in NaBH4 fuel is characterized using a comprehensive technique. A specific application is presented here, which includes the treatment of the spent fuel solution with anhydrous borax (Na2B4O7) at 90?°C for 3?h followed by calcination after the crystallization, resulting in the conversion of this highly caustic spent NaBH4 fuel into sodium metaborate (NaBO2), which is an environmentally friendlier and an economically valuable material. 相似文献
26.
Abidin GÜMRÜKÜOLU Aysel BAOLU Sevgi BAOLU Saliha BAOLU Meryem BAOLU Mira BAOLU Ümmühan BAOLU 《Turkish Journal of Chemistry》2020,44(1):99
Nitrogen-doped carbon nanodots (CDs) were prepared via the solvothermal method, using urea and triethylene glycol as the starting materials. The as-prepared CDs had individual diameters of approximately 100 nm and were in clusters of different sizes. The surface composition and optical properties of the as-prepared CDs were characterized. They exhibited multicolor emission properties in the visible range when excited with a wide wavelength range. The aqueous solution of the CDs was used in highly sensitive tartrazine determination. The fluorescence quenching of the CDs was in a linear relationship with the concentrations of tartrazine in the range of 0.5–30.0 μM. The detection limit of the assay was 0.18 μM. Acceptable recovery results were obtained via spike-recovery experiments on cookie samples. 相似文献
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Density, speed of sound, and conductivity of benzyldimethyltridecylazanium chloride as a cationic surfactant in aqueous solutions have been measured as a function of concentration at atmospheric pressure and at five temperatures (293.15, 298.15, 303.15, 308.15, and 313.15) K. Isentropic compressibility values have also been calculated from the experimental density and speed of sound results. The critical micelle concentration (cmc) values of investigated cationic surfactant were evaluated by using conductivity measurements. The speed of sound, isentropic compressibility and also the conductivity values of the solutions have been employed to determine the second critical micelle concentrations (2nd cmc). The temperature dependence of the speed of sound and isentropic compressibility is shown to be sensitive to the aggregation process. The 2nd cmc values of the surfactant obtained at different temperatures by conductivity, speeds of sound and isentropic compressibility data are in agreement with each other. 相似文献
29.
Microchimica Acta - A novel column solid phase extraction method was developed for the determination of Cu(II) and Fe(III) in various samples by flame atomic absorption spectrometry (FAAS) after... 相似文献
30.
Aysel Kantürk Figen Sabriye Piskin 《Particuology》2014,(6):158-164
In this study,the characterization and modification of waste magnesium chips(WMCs),which were produced by plastic molding in a gold manufacturing factory and are used as Mg-rich intermetallic composites in storing hydrogen,were discussed in detail.WMCs were analyzed using X-ray diffraction(XRD),X-ray fluorescence(XRF) spectroscopy,differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and Brunauer-Emmett-Teller(BET) analysis to characterize the materials’ structural properties.Mechanical milling,organic treatment,and inorganic salt addition were carried out to modify the WMCs’ surface to prepare Mg-rich intermetallic composites for storing hydrogen.The modified samples were analyzed using high-pressure volumetric analyses to calculate their hydrogen storage capacity.The authors conclude that modified WMC was promising as an Mg-rich intermetallic composite that was suitable for use in hydrogen storage with a 4.59 wt%capacity at 320 C under a hydrogen pressure of 60 bar. 相似文献