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  • Author or Editor: O. Doğru x
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In the present paper, we study a Kantorovich type generalization of Agratini's operators. Using A-statistical convergence, we will give the approximation properties of Agratini's operators and their Kantorovich type generalizations. We also give the rates of A-statistical convergence of these operators.

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In the present work, uranium concentration was determined in 15 soil samples by using CR-39 nuclear track detector and NaI(Tl) gammaspectroscopy. Obtained data are compared.

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On-line monitoring of soil radon (222Rn) concentration system was constructed on one of the main active fault zone of East Anatolian Fault System (EAFS) in Turkey. The preliminary results, observed during the second part of 2004 and first part of 2005 is presented. During the monitoring of soil radon concentration, numerous anomalies that equal or twice standard deviation were observed. In addition, the variation of the radon concentration was examined between the mean values and plus/minus two standard deviations and any increase in radon concentration above this limit was assumed to be 222Rn anomalies. These anomalies usually appeared between a few days or weeks before the earthquakes occurrence. The obtained data were also compared as considered respect to the earthquakes occurred in a 100 km radius of the fault system.

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222Rn concentrations along the seismic active area (some distinct in East Anatolian Active Fault System (EAFS), Turkey) were determined by using passive and active (prompt) methods including CR-39 and Markus-10, respectively. It was observed that the changing of 222Rn concentration along the fault lines, crossing the main East Anatolian Fault Line, has shown similar characteristics for both methods. The mean 222Rn concentrations were found to be between 1.2 and 3.6 kBq·m−3 and, 2 and 70 kBq·m−3 by using passive and prompt methods, respectively. Nevertheless, some measured terrestrial gamma-radiation dose rate in the same area has weak positive correlation to 222Rn concentration. Terrestrial gamma-dose rate at 1 m above the ground in the same sampling point, as for 222Rn concentration measurement were made, varied from 8.5 to 10.6 μR·h−1.

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This paper presents a case study of radioactive pollution of groundwater caused by leachate from an open landfill. Alpha- and beta-radioactivity analysis of the leachate from different points in the region and associated fountain water from a village down stream were carried out during four seasons. The alpha- and beta-radioactivity concentrations were under the detection limit in all samples and ranged between 0.07 and 2.17 Bq/l, respectively. The beta-radioactivity concentration from 129I, 137Cs and 90Sr individual radioisotopes were determined and their annual effective dose was calculated.

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In this paper we introduced the general sequence of linear positive operators via generating functions. Approximation properties of these operators are obtained with the help of the Korovkin Theorem. The order of convergence of these operators computed by means of modulus of continuity Peetre’s K-furictiorial and the elements of the usual Lipschitz class. Also we introduce the r-th order generalization of these operators and we evaluate this generalization by the operators defined in this paper. Finally we give some applications to differential equations.

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