Monitoring of anthropogenic and natural radionuclides and gamma absorbed dose rates in eastern Anatolia

2003 ◽  
Vol 258 (3) ◽  
pp. 547-550 ◽  
Author(s):  
S. Topcuoğlu ◽  
A. Türer ◽  
N. Güngör ◽  
Ç. Kırbaşoğu
2020 ◽  
Vol 8 (E) ◽  
pp. 678-684
Author(s):  
M. R. Usikalu ◽  
C. A. Enemuwe ◽  
R. O. Morakinyo ◽  
M. M. Orosun ◽  
T. A. Adagunodo ◽  
...  

Natural radionuclides are present in every constituent of the environment. Monitoring of environmental radionuclides is very vital to avoid exposure above the threshold limit. Due to this, the background radiation from 238U, 232Th, and 40K of Bell University of Technology and Canaan Land City was determined from 20 sample points each in the two areas using RS230 Gamma Spectrometer. The mean activity concentration of 40K, 238U, and 232Th for Bells University of Technology was 442.66 Bq/kg, 41.98 Bq/kg, and 48.35 Bq/Kg, respectively. In Canaan City, mean activity concentration of 40K, 238U, and 232Th was 373.65 Bq/kg, 18.85 Bq/kg, and 67.22 Bq/kg, respectively. The mean absorbed dose rates recorded by the spectrometer directly were 70.03 nGy/h and 66.65 nGy/h, while that estimated from the activity concentration were 67.06 and 64.89 nGy/h for Bells University and Canaan City, respectively. The measured and estimated absorbed dose rates were higher than the safe limit of 57 nGy/h. The mean values of other radiological parameters estimated, except that of the gamma index and excess lifetime cancer risk were lower when compared to the recommended limit. It could be concluded that the possibility of suffering any radiation risk is low in these two areas, but there is possibility of cancer risk for someone that has stayed in the area for 70 years and above.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3012
Author(s):  
Se Kye Park ◽  
Dong Yun Choi ◽  
Duyoung Choi ◽  
Dong Yun Lee ◽  
Seung Hwa Yoo

In this study, a high-density polyethylene (HDPE)-based carbon fiber-reinforced thermoplastic (CFRTP) was irradiated by an electron-beam. To assess the absorbed dose rate influence on its mechanical properties, the beam energy and absorbed dose were fixed, while the absorbed dose rates were varied. The tensile strength (TS) and Young’s modulus (YM) were evaluated. The irradiated CFRTP TS increased at absorbed dose rates of up to 6.8 kGy/s and decreased at higher rates. YM showed no meaningful differences. For CFRTPs constituents, the carbon fiber (CF) TS gradually increased, while the HDPE TS decreased slightly as the absorbed dose rates increased. The OH intermolecular bond was strongly developed in irradiated CFRTP at low absorbed dose rates and gradually declined when increasing those rates. X-ray photoelectron spectroscopy analysis revealed that the oxygen content of irradiated CFRTPs decreased with increasing absorbed dose rate due to the shorter irradiation time at higher dose rates. In conclusion, from the TS viewpoint, opposite effects occurred when increasing the absorbed dose rate: a favorable increase in CF TS and adverse decline of attractive hydrogen bonding interactions between HDPE and CF for CFRTPs TS. Therefore, the irradiated CFRTP TS was maximized at an optimum absorbed dose rate of 6.8 kGy/s.


1980 ◽  
Vol 175 (1) ◽  
pp. 17-18 ◽  
Author(s):  
William L. McLaughlin ◽  
Arne Miller ◽  
Stuart C. Ellis ◽  
Arthur C. Lucas ◽  
Barbara M. Kapsar

2010 ◽  
Vol 58 (spe4) ◽  
pp. 25-32 ◽  
Author(s):  
Wagner de S. Pereira ◽  
Alphonse Kelecom ◽  
Delcy de A. Py Júnior

A methodology was developed for converting the activity concentration of radionuclides (Bq kg-1) into absorbed dose rate (Gy y-1), aiming an approach to environmental radioprotection based on the concept of standard dose limit. The model considers only the internal absorbed dose rate. This methodology was applied to the cubera snapper fish (Lutjanus cyanopterus, Cuvier, 1828) caught off the coast of Ceará. The natural radionuclides considered were uranium-238, radium-226, lead-210, thorium-232 and radium-228. The absorbed dose rates were calculated for individual radionuclides and the type of emitted radiation. The average dose rate due to these radionuclides was 5.36 µGy y-1, a value six orders of magnitude smaller than the threshold value of absorbed dose rate used in this study (3.65 10³ mGy y-1), and similar to that found in the literature for benthic fish. Ra-226 and U-238 contributed 67% and 22% of the absorbed dose rate, followed by Th-232 with 10%. Ra-228 and Pb-210, in turn, accounted for less than 1% of the absorbed dose rate. This distribution is somewhat different from that reported in the literature, where the Ra-226 accounts for 86% of the absorbed dose rate.


2014 ◽  
Vol 12 (7) ◽  
pp. 774-781 ◽  
Author(s):  
Ioan Călinescu ◽  
Diana Martin ◽  
Daniel Ighigeanu ◽  
Adina Gavrila ◽  
Adrian Trifan ◽  
...  

AbstractElectron beam (EB) irradiation is a useful method to generate stable silver nanoparticles without the interference of inherent impurities generated from chemical reactions. Our experiments were carried out using linear electron beam accelerators with two different EB absorbed dose rates: 2 kGy min−1 and 7–8 kGy s−1, and with different absorbed dose levels. The optimum conditions for silver nanoparticles (AgNPs) generation by radiolysis, or by radiolysis combined with chemical reduction, were established. In order to obtain a good yield for AgNPs synthesized by radiolysis, a high dose rate is required, resulting in a rapid production process. At low absorbed dose rates, the utilization of a stabilization agent is advisable. By modifying the experimental conditions, the ratio between the chemical and radiolytic reduction process can be adjusted, thus it is possible to obtain nanoparticles with tailored characteristics, depending on the desired application.


2012 ◽  
Vol 293 (2) ◽  
pp. 649-654 ◽  
Author(s):  
K. S. Babai ◽  
S. Poongothai ◽  
K. S. Lakshmi ◽  
J. Punniyakotti ◽  
V. Meenakshisundaram

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