Calibration of HPGe Detectors for Environmental Samples Using GEANT4 Simulation

Determination of full energy peak efficiency is one of the most important tasks that have to be performed before gamma spectrometry. Calibration of the measurement system for measuring environmental samples poses a special challenge to the laboratory. Many different approaches to this task have been developed and examined. One of the most detailed is GEANT4, a Monte Carlo simulation toolkit developed for wide variety of applications. The aim of this paper is to apply GEANT4 simulation for calibration of three HPGe detectors, for measurement of aerosol, plant and coal-like environmental samples. The detectors were modeled using the certificate provided by the manufacturer. The samples chosen for the simulation were secondary reference materials produced in the Laboratory for the purpose of experimental calibration. The efficiencies obtained using a simulation were compared with experimental results, in order to evaluate the trueness of the results. Measurement uncertainties for both simulation and experimental values were estimated in order to see whether the results of the realistic measurement fall within acceptable limits.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr

Calibration of HPGe Detectors for Environmental Samples Using GEANT4 Simulation

Determination of full energy peak efficiency is one of the most important tasks that have to be performed before gamma spectrometry. Calibration of the measurement system for measuring environmental samples poses a special challenge to the laboratory. Many different approaches to this task have been developed and examined. One of the most detailed is GEANT4, a Monte Carlo simulation toolkit developed for wide variety of applications. The aim of this paper is to apply GEANT4 simulation for calibration of three HPGe detectors, for measurement of aerosol, plant and coal-like environmental samples. The detectors were modeled using the certificate provided by the manufacturer. The samples chosen for the simulation were secondary reference materials produced in the Laboratory for the purpose of experimental calibration. The efficiencies obtained using a simulation were compared with experimental results, in order to evaluate the trueness of the results. Measurement uncertainties for both simulation and experimental values were estimated in order to see whether the results of the realistic measurement fall within acceptable limits.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr

Supplementary data for article: Pantelić, M. M.; Zagorac, D. Č. D.; Ćirić, I. Ž.; Pergal, M. V.; Relić, D. J.; Todić, S. R.; Natić, M. M. Phenolic Profiles, Antioxidant Activity and Minerals in Leaves of Different Grapevine Varieties Grown in Serbia. Journal of Food Composition and Analysis 2017, 62, 76–83. https://doi.org/10.1016/j.jfca.2017.05.002

Supplementary material for: [https://doi.org/10.1016/j.jfca.2017.05.002]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2505]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3063

Correlation Between Beryllium-7 in Atmospheric Deposit and Ground Level Air in Serbia for 2014 Year

Activity density of beryllium-7 in atmospheric deposit and in ground level air at five monitoring stations (MS Nis, Vranje, Zajecar, Zlatibor, Palic) in Serbia were determined during the period January-December 2014. Activity of cosmogenic radionuclide beryllium-7 was determined on HPG detectors (Canberra, relative efficienty 20%.) by gama spectrometry method. Activity density of beryllium-7 in aerosols were in range 0.5 - 9.8 mBq/m(3) and in deposits were in range 1.8 - 233 Bg/m(2). Based on the obtained results correlation coefficient between aerosols and deposits was calculated and its value ranged from 0.15 to 0.59.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr

Results from Radionuclide Interlaboratory Comparison in Sediment and Fish

The results of an intercomparison exercise, designed for the determination of anthropogenic and natural radionuclides in sediment and fish samples from the Danube River, are reported. The methods of gross beta and gamma spectrometry measurements were compared. Considering the uncertainties of measurements, a good agreement between the results obtained by two laboratories has been ascertained.3rd International Conference on Radiation and Applications in Various Fields of Research (RAD), Jun 08-12, 2015, Budva, Montenegr

Chemical Characterization of Fruit Wine Made from Oblacinska Sour Cherry

This paper was aimed at characterizing the wine obtained from Oblacinska, a native sour cherry cultivar. To the best of our knowledge, this is the first paper with the most comprehensive information on chemical characterization of Oblacinska sour cherry wine. The chemical composition was characterized by hyphenated chromatographic methods and traditional analytical techniques. A total of 24 compounds were quantified using the available standards and another 22 phenolic compounds were identified based on the accurate mass spectrographic search. Values of total phenolics content, total anthocyanin content, and radical scavenging activity for cherry wine sample were 1.938 mg gallic acid eqv L-1, 0.113 mg cyanidin-3-glucoside L-1, and 34.56%, respectively. In general, cherry wine polyphenolics in terms of nonanthocyanins and anthocyanins were shown to be distinctive when compared to grape wines. Naringenin and apigenin were characteristic only for cherry wine, and seven anthocyanins were distinctive for cherry wine

Assessment of natural radioactivity levels and radon exhalation rate potential from various building materials

Various imported building materials commonly used in construction and industry in Serbia were analyzed using gamma spectrometry. Based on the activity concentrations of 226Ra, 232Th, and 40K in the investigated samples, radium equivalent activity, Raeq, absorbed dose rate, D, annual effective dose, DE, and the external hazard index, Hex, were calculated to assess the radiation hazard for people. The Raeq for most of the analyzed samples (416 in total) was lower than the maximum admissible value of 370 Bqkg-1 set in the UNSCEAR report. The absorbed gamma dose rate in air was found to vary from 0.030 mGyh-1 to 1.328 mGyh-1 which in some cases exceeded indoor dose rates in Europe. The obtained values for annual effective dose exceed the limits of 0.41 mSv given in literature for about 5 % of measured samples, while values of Hex were higher than unity for three samples of cement, eight samples of granite, and one sand sample. As a possible source of elevated effective dose, the radon exhalation from building materials was estimated using the parameters given in literature. The internal dose due to 222Rn exhaled from the building material was found to be up to nine times higher than external dose due to 226Ra content in some cases

Influence of sample preparation on measurement of low concentration of radiocaesium in fresh water - review of the intercomparison results

U februaru 2017. godine, u Beču je održan radionica pod imenom Data Evaluation Workshop on Determination of Low Activity Radio-Caesium in Freshwater, kao deo projekta RER/7/008 - Strengthening Capabilities for Radionuclide Measurement in the Environment and Enhancing Quality Assurance/Quality Control System for Environmental Monitoring. Ukupno 31 laboratorija iz 29 zemalja Evrope i Japana, uzela je učešća u ovoj radionici. Pre početka radionice, laboratorije učesnice su dobile uzorke površinske vode iz Japana i Dunava, kao i QA/QC uzorak vode poznate aktivnosti, za interkomparaciju. Zadatak je bio određivanje veoma niske koncentracije 134Cs i 137Cs u ovim uzorcima, uz korišćenje različitih metoda pripreme – prekoncentracije uzoraka. Laboratorije učesnice su u pripremi koristile uparavanje do suvog ostatka ili definisane zapremine, hemijsko obogaćivanje ili jon – izmenjivačke metode, sa ciljem da se concentriše sadržaja radiocezijuma u uzorcima. Iako su ispitivani radionuklidi bili prisutni u koncentracijama reda veličine 10-2 Bq/kg, rezultati laboratorija učesnica su bili u velikoj većini prihvaćeni. Ipak, identifikovani su neki problem vezani za prinos metode u hemijskom obogaćivanju i gubitke prilikom uparavanja. U ovom radu biće predstavljen pregled rezultata ove interkomparacije i analiziran uticaj metode pripreme uzoraka na dobijene rezultate.Workshop named Data Evaluation Workshop on Determination of Low Activity Radio-Caesium in Freshwater was held in February 2017 in Vienna, as a part of project RER/7/008 - Strengthening Capabilities for Radionuclide Measurement in the Environment and Enhancing Quality Assurance/Quality Control System for Environmental Monitoring. Total of 31 participating laboratories from 29 European countries and Japan took part in this workshop. Prior to the workshop, the participating laboratories received samples of fresh water from Japanese rivers and Danube, as well as the QA/QC sample of known activity. The task was to determine very low concentrations of 134Cs and 137Cs in these samples using some method of sample preparation - preconcentration. The laboratories used total evaporation, evaporation to a finite volume, chemical enrichment and ion exchange methods in order to concentrate the radiocaesium in the samples. Despite the very low concentration of analytes in the samples (order of magnitude 10-2 Bq/kg), the results of participating laboratories were for the most part acceptable. However, some difficulties regarding chemical yield in chemical enrichment procedures and loss of the sample during evaporation were identified. The aim of this paper is to represent the overall results of the said intercomparison and to analyze the influence of the preparation method on the obtained results.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Радиоактивност атмосфере у Институту за нуклеарне науке "Винча" у периоду од 1985-2915

Institutu za nuklearne nauke "Vinča", dugi niz godina praćena je vremenska distribucija aktivnosti prirodnih i veštačkih radionuklida u prizemnom sloju atmosfere i padavinama. Aktivnosti prirodnih radionuklida 7Be i 210Pb, kao i veštačkog radionuklida 137Cs, određene su gamaspektrometrijskom metodom, dok je aktivnost 3H (može biti i prirodnog i veštačkog porekla) određena metodom tečne scintilacione spektrometrije. Ujedno je ispitivana i ukupna beta aktivnost, koja predstavlja indikatorsko merenje nivoa kontamincije atmosfere. U periodu ispitivanja, dogodila su se dva velika nuklearna akcidenta, 1986. u Černobilju i 2011. u Fukušimi, koja su doprinela povećanju koncentracije veštačkih radionuklida u životnoj sredini. U toku ovih događaja, praćena je dnevna promena koncentracije veštačkih radionuklida 137Cs, 134Cs i 131I u atmosferi. Na osnovu rezultata dugogodišnjih merenja, određene su srednje mesečne koncentracije aktivnosti, pokretne sredine kao i mesečni i kvartalni indeksi za navedene radionuklide, iz kojih su uočeni sezonski efekti. Maksimalne aktivnosti 7Be i 3H dostižu u letnjem, a minimalne u zimskom periodu. U slučaju 210Pb, aktivnosti su bile maksimalne u jesenjim, a minimalne u prolećnim mesecima. Za radionuklid 137Cs, maksimalne aktivnosti su dobijene u mesecima prelaska proleća u leto i jeseni u zimu (manje izražen maksimum).A long term measurements of temporal distribution of naturally occurring and artificial radionuclides in the ground level air are conducted for many years in the Institute for Nuclear Sciences "Vinča". Activity of naturally occurring radionuclides 7Be i 210Pb and artificial radionuclide 137Cs is determined via gamma spectrometry and activity of 3H in precipitation (which can be both naturally occurring and artificial) is determined using liquid scintilation spectrometry. Along these, gross alpha and beta activity measurements are also conducted. These measurements represent the indicative of atmospheric contamination. During the period of this monitoring, two major nuclear accidents have taken place – the one in Chernobyl 1986 and the accident in Fukushima 2011, that have contributed to the rise in the activity concentration of the artificial radionuclides 137Cs, 134Cs , 131I and 3H in the environment. Based on the results of these long term measurements, average monthly activities, monthly and seasonal indices for the mentioned radionuclides were determined and seasonal periodical effects were noticed. Maximum values of 7Be and 3H were noticed in summer and minimum values were noticed in the winter. In case of 210Pb, activity concentration reached its maximum in autumn and minimum in spring. For 137Cs, maximal values were detected in the months between the season of spring and summer and autumn to winter (less pronounced maximum).Article is part of: [http://vinar.vin.bg.ac.rs/handle/123456789/8230

Радиоактивност атмосфере у Институту за нуклеарне науке "Винча" у периоду од 1985-2915

Institutu za nuklearne nauke "Vinča", dugi niz godina praćena je vremenska distribucija aktivnosti prirodnih i veštačkih radionuklida u prizemnom sloju atmosfere i padavinama. Aktivnosti prirodnih radionuklida 7Be i 210Pb, kao i veštačkog radionuklida 137Cs, određene su gamaspektrometrijskom metodom, dok je aktivnost 3H (može biti i prirodnog i veštačkog porekla) određena metodom tečne scintilacione spektrometrije. Ujedno je ispitivana i ukupna beta aktivnost, koja predstavlja indikatorsko merenje nivoa kontamincije atmosfere. U periodu ispitivanja, dogodila su se dva velika nuklearna akcidenta, 1986. u Černobilju i 2011. u Fukušimi, koja su doprinela povećanju koncentracije veštačkih radionuklida u životnoj sredini. U toku ovih događaja, praćena je dnevna promena koncentracije veštačkih radionuklida 137Cs, 134Cs i 131I u atmosferi. Na osnovu rezultata dugogodišnjih merenja, određene su srednje mesečne koncentracije aktivnosti, pokretne sredine kao i mesečni i kvartalni indeksi za navedene radionuklide, iz kojih su uočeni sezonski efekti. Maksimalne aktivnosti 7Be i 3H dostižu u letnjem, a minimalne u zimskom periodu. U slučaju 210Pb, aktivnosti su bile maksimalne u jesenjim, a minimalne u prolećnim mesecima. Za radionuklid 137Cs, maksimalne aktivnosti su dobijene u mesecima prelaska proleća u leto i jeseni u zimu (manje izražen maksimum).A long term measurements of temporal distribution of naturally occurring and artificial radionuclides in the ground level air are conducted for many years in the Institute for Nuclear Sciences "Vinča". Activity of naturally occurring radionuclides 7Be i 210Pb and artificial radionuclide 137Cs is determined via gamma spectrometry and activity of 3H in precipitation (which can be both naturally occurring and artificial) is determined using liquid scintilation spectrometry. Along these, gross alpha and beta activity measurements are also conducted. These measurements represent the indicative of atmospheric contamination. During the period of this monitoring, two major nuclear accidents have taken place – the one in Chernobyl 1986 and the accident in Fukushima 2011, that have contributed to the rise in the activity concentration of the artificial radionuclides 137Cs, 134Cs , 131I and 3H in the environment. Based on the results of these long term measurements, average monthly activities, monthly and seasonal indices for the mentioned radionuclides were determined and seasonal periodical effects were noticed. Maximum values of 7Be and 3H were noticed in summer and minimum values were noticed in the winter. In case of 210Pb, activity concentration reached its maximum in autumn and minimum in spring. For 137Cs, maximal values were detected in the months between the season of spring and summer and autumn to winter (less pronounced maximum).Article is part of: [http://vinar.vin.bg.ac.rs/handle/123456789/8230