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A simple, sensitive and rapid derivative spectrophotometric method using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) has been developed for simultaneous determination of Co(II), Ni(II) and Fe(II) which have very similar chemical behavior and appear together in many real samples. The complexes of all these metal ions with 5-Br-PADAP were formed immediately at pH 7.0 ammonium acetate buffered solution and were stable for at least 24 h. Second derivative spectra were selected for evaluation, because working wavelength determination was more precise and spectral overlap was less than in the ordinary and first derivative spectra. Three wavelengths at which the complexes exhibit extremum 2D values for Co(II), Ni(II) and Fe(II) were selected as analytical wavelengths, i.e., 640, 600 and 740 nm, respectively. Calibration curves drawn with zero-to-peak values at mentioned wavelengths were linear between 80 and 2000 ng ml−1 for each metal ion. Concentrations of Co(II) and Ni(II) were calculated from the total 2D values and the sum of the linear equations for these three cations at 640 and 600 nm, after Fe(II) assay by making use of the 2D value at 740 nm. Limits of detection (LOD) for Co(II), Ni(II) and Fe(II) were 2.7, 13.9 and 3.0 ng ml−1, respectively. The method has been applied to tool steel and heater resistance wire samples successfully. 相似文献
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Avcıbaşı Uğur Türkyarar Taner Karadağ Ayşegül Bakan Buket Yavaşoğlu Nefise Ülkü Karabay Kuşat Kevser Akgöl Sinan Gülcemal Derya Tekin Volkan Müftüler Fazilet Zümrüt Biber Topal Gökcen Parlak Yasemin Gümüşer Fikriye Gül 《Journal of Radioanalytical and Nuclear Chemistry》2021,329(2):511-525
Journal of Radioanalytical and Nuclear Chemistry - The aim of this study is the synthesis of a novel 99mTc-labeld graft polymer and the biological evaluation of its in vitro and in vivo properties.... 相似文献
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Kevser Cirik 《Applied biochemistry and biotechnology》2014,173(1):205-214
Effective wastewater treatment and electricity generation using dual-chamber microbial fuel cell (MFC) will require a better understanding of how operational parameters affect system performance. Therefore, the main aim of this study is to investigate the bioelectricity production in a dual-chambered MFC-operated batch mode under different operational conditions. Initially, platinum (Pt) and mixed metal oxide titanium (Ti-TiO2) electrodes were used to investigate the influence of the electrode materials on the power generation at initial dissolved organic carbon (DOC) concentration of 400 mg/L and cycle time of 15 days. MFC equipped with Ti-TiO2 electrode performed better and was used to examine the effect of influent DOC concentration and cycle time on MFC performance. Increasing influent DOC concentration resulted in improving electricity generation, corresponding to a 1.65-fold increase in power density. However, decrease in cycle time from 15 to 5 days adversely affected reactor performance. Maximum DOC removal was 90?±?3 %, which was produced at 15-day cycle time with an initial DOC of 3,600 mg/L, corresponding to maximum power generation of about 7,205 mW/m2. 相似文献
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In a recent paper Lal and Yadov [4] obtained a theorem on the degree of approximation for a function belonging to the Lipschitz class Lipα using the product of the Cesàro and Euler means of order one of its Fourier series. In this paper we extend this result to any regular Hausdorff matrix for the same class of functions. 相似文献
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Maria Maares M. Menaf Ayhan Kai. B. Yu A. Ozgur Yazaydin Kevser Harmandar Hajo Haase Jens Beckmann Yunus Zorlu Gündoğ Yücesan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(48):11214-11217
A new family of porous metal–organic frameworks (MOFs), namely alkali phosphonate MOFs, is reported. [Na2Cu(H4TPPA)] ⋅ (NH2(CH3)2)2 ( GTUB-1 ) was synthesized using the tetratopic 5,10,15,20-tetrakis[p-phenylphosphonic acid] porphyrin ( H8-TPPA ) linker with planar X-shaped geometrical core. GTUB-1 is composed of rectangular void channels with BET surface area of 697 m2 g−1. GTUB-1 exhibits exceptional thermal stability. The toxicity analysis of the ( H8-TPPA ) linker indicates that it is well tolerated by an intestinal cell line, suggesting its suitability for creating phosphonate MOFs for biological applications. 相似文献
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Robert R. Fraser Kasturi L. Dhawan Kevser Taymaz 《Magnetic resonance in chemistry : MRC》1978,11(6):269-274
The 13C NMR spectra of a series of 4-t-butylcyclohexane-O-methyl oximes and N,N-dimethylhydrazones containing α-methyl substituents have been measured. The effects of α-methyl substitution (syn-axial, anti-axial and anti-equatorial) on the carbons α, β and γ to the substitution site are similar to those previously found in cyclohexanones. Use has been made of these substituent parameters to determine the conformational equilibria of the mobile 2-methylcyclohexanone derivatives. 相似文献
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We study the arithmetic properties of hyperelliptic curves given by the affine equation y2 = xn+a by exploiting the structure of the automorphism groups. We show that these curves satisfy Lang’s conjecture about the covering radius (for some special covering maps). 相似文献