Browsing by Author "Ceylan, H."

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238u and 222rn Activity Concentrations and Total Radioactivity Levels in Lake Waters
(Springer, 2013) Zorer, O. Selcuk; Sahan, T.; Ceylan, H.; Dogru, M.; Sahin, S.
The concentrations and distributions of natural radioactivity, uranium and radon in lake waters from around Van, Turkey were investigated with an aim of evaluating the environmental radioactivity. Fourteen lake waters were collected from different six lakes around Van (Turkey) to determine U-238, Rn-222 and total alpha and total beta distributions in 2009. The total alpha and total beta activities were counted by using alpha/beta counter of the multi-detector low background system (PIC-MPC-9604) and the U-238 concentrations were determined by inductively coupled plasma-mass spectrometry (Thermo Scientific Element 2) and radon concentrations were measured with the solid state nuclear track detector technique. The activity concentrations ranging from ND to 0.039 Bq L-1 and from 0.026 to 3.728 Bq L-1 for total alpha and beta, respectively, and uranium concentrations ranging from 0.083 to 3.078 mu g L-1, and radon concentrations varying between 47.80 and 354.86 Bq m(-3) were observed in the lake waters.
Adsorption of Aniline, Phenol, and Chlorophenols on Pure and Modified Bentonite
(Maik Nauka/interperiodica/springer, 2006) Yildiz, A.; Gur, A.; Ceylan, H.
In the present study, pure bentonite and bentonite modified by HNO 3, EDTA, and HDTMA are adsorbents. The changes on the surfaces of bentonite samples are studied by IR spectroscopy. The adsorption of aniline, phenol, and phenol derivatives on these adsorbents is examined by means of gas chromatography. As the result of these examinations, it is seen that the adsorption capacities of clay-organic complexes (bentonite - EDTA and bentonite-HDTMA) are higher than those of bentonite-HNO3 and pure bentonite.
Dissolution Kinetics of Calcined Ulexite in Ammonium Chloride Solutions
(Mrs Pushpa Agarwal, 2006) Gur, A.; Yildiz, A.; Ceylan, H.
In this study, the leaching kinetics of calcined ulexite in ammonium chloride solutions were investigated. The effect of calcination temperature, solution concentration, reaction temperature and prehydration were chosen as parameters. It was observed that the rate of dissolution increased with increasing calcination temperature, solution concentration and reaction temperature, while it was not affected by prehydration. Employing graphical and statistical methods, the dissolution rate, based on homogeneous reaction model, can be shown as: (1 - X)(-1) - 1 = k(NH4Cl)(4/5). The activation energy for the dissolution of the ulexite sample calcined at 160 degrees C was found to be 62.65 kJ mol(-1).
Erratum: Effects of Some Drugs on Enzyme Activity of Catalase From Bovine Liver (Asian Journal of Chemistry (2006) 18, 1 (601-607))
(Chemical Publishing Co., 2006) Alkan, S.; Savran, A.; Demir, H.; Ceylan, H.
The Investigation of the Adsorption of Propylamine, Dipropylamine and Tripropylamine on Sepiolite Specimens by Infrared Spectroscopy
(1999) Selçuk, A.; Sarıkaya, Y.; Alemdaroğlu, T.; Ceylan, H.
Propylamine, dipropylamine and triplopylamine were adsorbed on sepiolite specimens under reflux, at their normal boiling points. The infrared spectra of the original and the amine adsorbed specimens were recorded before and after heat treatments between 50-$400^circ C$. The examination of the spectra revealed that the adsorption of amines took place by the replacement of the zeolitic water in the pores of the sepiolite by the amines.