Browsing by Author "Koray, Abdullah"

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Beta parçacıklarının enerji spektrumlarının vavilov dağılımı ile incelenmesi
(Uludağ Üniversitesi, 2002-08-06) Koray, Abdullah; Cengiz, Ahmet; Uludağ Üniversitesi/Fen Bilimleri Enstitüsü/Fizik Anabilim Dalı.
Al ve Cu tabakaları geçen Tl - 204 'im ß~ parçacıklarının enerji dağılımları ve enerji kaybı dağılımları Fermi Teorisi ile Vavilov Dağılımı kullanılarak hesaplanmıştır. ß~ parçacıklarının iç ve dış bremsstrahlung ışıma kayıpları gözönüne alınmamıştır. Tl - 204,ün tabakaları geçen ß~ parçacıklarının elde edilen enerji spektrumları deneysel spektrumlarla uyuşmaktadır. ß~ parçacıklarının Al ve Cu için kütle zayıflama katsayıları, tabaka kalınlığına bağlı geçme katsayılarının yan logaritmik çiziminin eğimi olarak elde edilmiştir. ß~ parçacıklarının elde edilen kütle zayıflama katsayıları deneysel değerlerle iyi uyuşmaktadır.
Correlation of radon and thoron concentrations with natural radioactivity of soil in Zonguldak, Turkey
(Amer Inst Physics, 2017) Koray, Abdullah; Akkuş, B.; Öktem, Y.; Doğan, G. S.; Güzelçimen, F.; Akkaya, Gizem; Kahraman, Ayşegül; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 0000-0002-1836-7033; AAH-8784-2021; AAH-6441-2021; 18036694200; 47161190600
Radon and thoron gases are produced by the decay of the radioactive elements those are radium and thorium in the soil. In this study, the correlations between soil radon and thoron concentration with their parent nuclide (Ra-226 and Th-232) concentrations in collected soil samples from the same locations were evaluated. The result of the measurement shows that the distribution of radon and thoron in soil showed the same tendency as Ra-226 and Th-232 distribution. It was found a weak correlation between the radon and the Ra-226 concentration (R =0.57), and between the thoron and the Th-232 concentration (R=0.64). No strong correlation was observed between soil-gas radon and thoron concentration (R=0.29).
The effect of elastic scattering cross section to multiple-scattering of electrons
(Amer Inst Physics, 2007) Koray, Abdullah; Aytekin, Hüseyin; Cengiz, Ahmet; Uludağ Üniversitesi/Fen Edebiyat Fakültesi/Fizik Bölümü.; AAH-7446-2021; 18534116600
A Monte Carlo code is developed which simulates the interactions and transport of electron within a given medium. The angular distributions of the electrons transmitted through a medium of definite thickness are obtained by using this code. In order to investigate the contribution of elastic scattering to multiple-scattering, the angular distrubutions obtained by using the Rutherford differential cross section (DCS) modified by screening correction are compared with the results obtained from the uniform distribution (the constant differential elastic scattering cross section).
The investigation of radionuclide concentrations in soil and lifetime cancer risk due to gamma radioactivity in Zonguldak, Turkey
(Polish Acad Sciences Inst Physics, 2017-09) Koray, Abdullah; Baldık, Rıdvan; Akkaya, Gizem; Kahraman, Ayşegül; Kaynak, Gökay; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 0000-0002-1836-7033; AAH-8784-2021; AAH-6441-2021; 18036694200; 47161190600; 12042075600
The distributions of Ra-226, Th-232, K-40 and Cs-137 activity concentrations were determined using a high-purity germanium detector in uncultivated surface soil samples collected from Zonguldak. The range of Ra-226, Th-232, K-40 and 137Cs activity concentrations varied from 10.5 +/- 2.0 to 98.0 +/- 4.3 Bq kg(-1) (mean value 28.8 +/- 4 Bq kg(-1)), from 12.9 +/- 3.4 to 53.2 +/- 5.1 Bq kg(-1) (mean value 29.6 +/- 3 Bq kg(-1)), from 190 +/- 22 to 808 +/- 43 Bq kg(-1) (mean value 395 +/- 31 Bq kg(-1)) and from < 0.5 to 47.1 +/- kg(-1) (mean value 12.5 +/- 2 Bq kg(-1)), respectively. In addition, the mean outdoor absorbed dose rates in air (terrestrial, terrestrial+cosmic), annual effective dose equivalent, radium equivalent activity and external hazard index were found to be 48 nGy h(-1) (terrestrial), 56 nGy h(-1) (terrestrial+cosmic), 58 mu Sv y(-1), 101 Bq kg(-1) and 0.27, respectively. The evaluated excess lifetime cancer risks (ELCRs) varied from 0.13 x 10(-3) to 0.36 x 10(-3) with a mean value of 0.20 x 10(-3).
Measurements of radon concentrations in waters and soil gas of Zonguldak, Turkey
(Oxford University Press, 2014-12) Koray, Abdullah; Akkaya, Gizem; Kahraman, Ayşegül G.; Kaynak, Gökay; Uludağ Üniversitesi/Fen Edebiyat Fakültesi/Fizik Bölümü.; 0000-0002-1836-7033; AAH-6441-2021; AAH-8784-2021; CYZ-0032-2022; 18036694200; 47161190600; 12042075600
The radon concentrations in soil-gas and water samples (in the form of springs, catchment, tap, thermal) used as drinking water or thermal were measured using a professional radon monitor AlphaGUARD PQ 2000PRO. The measured radon concentrations in water samples ranged from 0.32 to 88.22 Bq l-1. Most of radon levels in potable water samples are below the maximum contaminant level of 11 Bq l-1 recommended by the US Environmental Protection Agency. The calculated annual effective doses due to radon intake through water consumption varied from 0.07 to 18.53 μSv y-1. The radon concentrations in soil gas varied from 295.67 to 70 852.92 Bq m-3. The radon level in soil gas was found to be higher in the area close to the formation boundary thrust and faults. No correlation was observed between radon concentrations in groundwater and soil gas. Also, no significant correlation was observed between soil-gas radon and temperature, pressure and humidity. The emanation of radon from groundwater and soil gas is controlled by the geological formation and by the tectonic structure of the area. © The Author 2013. Published by Oxford University Press. All rights reserved.
Variation in the radon concentrations and outdoor gamma radiation levels in relation to different geological formations in the thermal regions of Bursa, Turkey
(IOP Publishing, 2016-05-13) Koray, Abdullah; Akkaya, Gizem; Kahraman, Ayşegül; Kaynak, Gökay; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü.; 0000-0002-1836-7033; AAH-6441-2021; AAH-8784-2021; 18036694200; 47161190600; 12042075600
Spring waters used as spas and their region may contain significant amounts of natural radionuclides. The main sources of exposure are the inhalation of radon and its decay products released from the water and soil and terrestrial gamma-radiation. In order to evaluate the potential risk of thermal regions in Bursa, located in the impact area of the NAF (North Anatolian Fault), radon and thoron concentrations in soil gas, radon concentrations in thermal waters and outdoor gamma radiation levels were measured in thermal regions that have different geological formations. The radon and thoron concentrations in soil-gas were found to vary from 2272 +/- 121 to 245196 +/- 3455 Bq m(-3) and from 999 +/- 218 to 178 848 +/- 17 742 Bq m(-3), respectively. The radon concentrations in thermal waters ranged from 0.99 +/- 0.21 to 226.74 +/- 2.51 Bq l(-1) in the rainy season and from 0.26 +/- 0.10 to 178.03 +/- 12.86 Bq l(-1) in the dry season. The measured outdoor gamma radiation levels varied from 38 to 180 nGy h(-1). The gamma dose rates were found to be strong positively correlating with the radon and thoron concentrations in soil-gas. The radon and outdoor gamma radiation levels were observed to be a function of the geological formations of the area.