Browsing by Author "Kahraman A."

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Calculation of angular distribution of 662 keV gamma rays by Monte Carlo method in copper medium
(2009-12-01) Kahraman A.; Ozmutlu E.; Gurler O.; Yalcin S.; Kaynak G.; Gundogdu O.
This paper presents results on the angular distribution of Compton scattering of 662 keV gamma photons in both forward and backward hemispheres in copper medium. The number of scattered events graph has been determined for scattered gamma photons in both the forward and backward hemispheres and theoretical saturation thicknesses have been obtained using these results. Furthermore, response function of a 51×51 mm NaI(Tl) detector at 60° angle with incoming photons scattered from a 10 mm thick copper layer has been determined using Monte Carlo method. © 2009 Elsevier Ltd. All rights reserved.
Investigation of environmental contamination in lichens of Gökçeada (Imbroz) Island in Turkey
(2009-02-01) Kahraman A.; Kaynak G.; Gurler O.; Yalcin S.; Ozturk S.; Gundogdu O.
The main objective of the present study is to determine the type of environmental contamination in lichens in Gökçeada Island in the Northern Aegean Sea in Turkey. We used two different lichen species Cladonia foliacea and Ramalina pollinaria. In the first part of the investigation, the beta activities of lichens have been measured by using a TENNELEC LB 1000-PW detector. The range of beta activity values was between 607 ± 30 and 308 ± 12 Bq/kg for C. foliacea lichens collected from around Tuz Lake and values for R. pollinaria lichens were found to be 740 ± 25 and 541 ± 17 Bq/kg. The second part of the study was concerned with the gamma spectra of the lichen samples measured by using HpGe detector. 137Cs, 134Cs, 40K, 232Th, 226Ra radionuclides were found in C. foliacea collected from around Tepeköy and in R. pollinaria from around Tuz Lake. When these two types of lichens were compared, it was found that R. pollinaria contain more radionuclides. In order to compare and determine which of these lichens act as a better bioaccumulator, K, Mn, Zn, Rb, Sr, Ba and Pb metal content were determined by using Energy Dispersive X-ray fluorescence spectrometry. It was found that C. foliacea collected more Mn and Sr when compared to R. pollinaria. © 2009 Elsevier Ltd. All rights reserved.
Measurements of radium levels in bottled natural spring water of marmara region (Turkey)
(2012-09-24) Akar U.; Gurler O.; Kahraman A.; Yalcin S.; Kaynak G.; Gundogdu O.
Drinking water may contain varying levels of radioactivity. It is therefore important to determine the radium levels in drinking waters for public health and radiation protection. This paper presents results of 226Ra concentrations in bottled spring waters. The concentration of radium has been assessed in the bottled natural spring water samples commercially available in Turkey. Measurements of 226Ra concentrations in bottled natural spring water samples were carried out by AlphaGUARD, measuring the radon in equilibrium with radium. The radium concentration in these samples is found to be between 0.03 and 0.43 Bq·L-1. These values were compared with the recommended safe limits for drinking water.
Measurements of radon levels in thermal waters of Bursa, Turkey
(2010-12-01) Gurler O.; Akar U.; Kahraman A.; Yalcin S.; Kaynak G.; Gundogdu O.
Radon (222Rn) is a tasteless, colourless and odourless radioactive noble gas, responsible for approximately 50% of radiation from natural sources. Being highly soluble in water, radon in water sources is also a major public health concern and is still an active research area. This paper presents the results of radon concentration measurements in thermal water samples from Çekirge region of the city of Bursa, rich in geothermal waters located in the northwest part of Turkey. The radon activity concentrations in 36 thermal water samples were determined by using AlphaGUARD PQ 2000PRO radon gas analyser. AlphaGUARD is an ionizing chamber which measures radon via alpha spectrometric techniques. It is found that the concentration ranged from 2.513 + 0.286 to 82.55311.919 Bq·L-1 for radon. The doses delivered to the users during treatment were also calculated and found to be in the range of 0.36 nSv to 11.89 nSv per treatment. © by PSP.
Radioactivity measurements in epiphytic lichens of Uludaǧ Mountain in Western Anatolia
(2013-01-01) Kahraman A.; Kaynak G.; Akkaya G.; Gürler O.; Yalçın S.
Activity concentrations of gross-β, naturally occurring 226 Ra, 232 Th, 210 Pb, 7 Be and anthropogenic 137 Cs in epiphytic lichens collected from Uludaǧ Mountain are presented and discussed with the aim of evaluating potential usability of lichens as a biomonitor. The activity concentrations of gross-β, 137 Cs, 40 K, 226 Ra, 232 Th, 210 Pb and 7 Be in the lichen samples were found to be in the range of 177-707, 4.05-94.26, 86-211, below detection limit (BDL) - 19.2, BDL - 14.0, 229-872, and 72.1-220.7 Bq kg -1 in dry weight, respectively. 137 Cs content in collected epiphytic lichens was in descending order: Parmelia sulcata > Lobaria pulmonaria > Pseudevernia furfuracea > Usnea filipendula. The best biomonitor for 137 Cs among the lichen species used in this study was determined as Parmelia sulcata. Pearson's correlation coefficient was calculated between 137 Cs and 40 K activity concentrations using a statistical package program (SPSS ver. 17.0) and a negative correlation value (R = -0,323, p = 0,222) was obtained. The highest 226 Ra and 232 Th activity concentrations were found in Boǧazova YaylasI which has a geological structure including granitic rocks. It was found that 137 Cs and 7 Be activity concentrations in species demonstrated an inverse behaviour. The effect of mean annual precipitation and temperature on 7 Be activity concentration was determined using multi regression analysis. Also, correlations between the 137 Cs and 7 Be, and 40 K and 7 Be were investigated. © 2012 Akadémiai Kiadó, Budapest, Hungary.