Measurement of radon concentration in kindergartens and schools in Nis, Serbia

2019 ◽  
Vol 17 (2) ◽  
pp. 191-197
Author(s):  
Vesna Manic ◽  
Goran Manic ◽  
Branko Radojkovic ◽  
Dusica Vucic ◽  
Dragoslav Nikezic ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Gamma Spectrometry ◽  
Radon Concentration ◽  
Hpge Detector ◽  
Activity Concentration ◽  
Average Value ◽  
Activity Concentrations ◽  
Log Normal ◽  
The Town ◽  
Log Normal Distribution

In this study, the activity concentration of radon, 222Rn, in kindergartens and schools in the town of Nis, Serbia, was explored. The method of active charcoal was applied. The measurements were carried out by gamma - spectrometry with HPGe detector. The results belong to the range of 15 Bq/m3 - 256 Bq/m3, with an average value of 59.7 Bq/m3 and a standard deviation of 25.3 Bq/m3. It was shown that data are distributed according to the log-normal distribution, and that is no correlation between indoor 222Rn concentrations and the activity concentrations of radium, 226Ra, in the soil.

Variance of ventilation during exercise

2001 ◽  
Vol 90 (6) ◽  
pp. 2151-2156 ◽  
Author(s):  
Kenneth C. Beck ◽  
Theodore A. Wilson
Keyword(s):  
Standard Deviation ◽  
Normal Distribution ◽  
Ventilation Distribution ◽  
Cycle Exercise ◽  
Expired Gas ◽  
Highly Correlated ◽  
Log Normal ◽  
Male Subjects ◽  
Log Normal Distribution ◽  
Ventilation And Perfusion

Expired gas concentrations were measured during a multibreath washin of He in one female and seven male subjects at rest (seated) and during cycle exercise at work rates of 70–210 W. In a computational model, the ventilation distribution was represented as a log-normal distribution with standard deviation (ςV˙); values of ςV˙ were obtained by fitting the output of the model to the data. At rest, ςV˙ was 0.89 ± 0.18; during exercise, ςV˙ was 0.60 ± 0.13, independent of the level of exercise. These values for the width of the functional ventilation distribution at the scale of the acinus are approximately two times larger than those obtained from anatomic measurements in animals at a scale of 1 cm3. The values for ςV˙, together with data from the literature on the width of the functional ventilation-perfusion distribution, show that ventilation and perfusion are highly correlated at rest, in agreement with anatomic data. The structural sources of nonuniform ventilation and perfusion and of the correlation between them are unknown.

scholarly journals Retrospective radon measurements based on implanted 210Po in glass objects using polycarbonate detectors

2018 ◽  
Vol 33 (2) ◽  
pp. 167-173
Author(s):  
Alireza Azadbar ◽  
Dariush Sardari ◽  
Mohamadreza Kardan ◽  
Samaneh Baradaran
Keyword(s):  
Solid State ◽  
Radon Concentration ◽  
Activity Concentration ◽  
Diffusion Chamber ◽  
Average Value ◽  
Nuclear Track Detectors ◽  
210Po Activity ◽  
Cylindrical Diffusion ◽  
Radon Measurements ◽  
First Time

In the present investigation, a surface-deposited polonium was measured in 37 houses in Rasht and Ramsar cities of Iran with the aim of evaluating the retrospective radon concentration. The CR-LR technique is widely used in this regard, but for the first time, Lexan polycarbonate detectors were used to measure the activity of 210Po planted in glassy objects. These detectors were placed on glassy surfaces for 153 to 365 days. A passive cylindrical diffusion chamber was used for the contemporary radon concentration measurements. The diffusion chamber consists of the Lexan polycarbonate films as a solid state nuclear track detectors and filter. The surface-deposited 210Po activity concentration was found to vary from 0.26 to 11.96 mBqcm-2 with average of 2.62 mBqcm-2. The sensitivity of 210Po to polycarbonate was determined to be 0.06456 track per cm2 per mBqhcm-2. Thus, the radon concentration was found to vary from 122 to 4840 Bqm-3 with an average value 1243 Bqm-3 and the contemporary radon concentration in the area was found to vary from 15 to 2420 Bqm-3 with an average 513 Bqm-3. The results indicate that there is a significant correlation between the concentration of the retrospective radon and the concentration of the contemporary radon gas in the indicated areas with a coefficient of 0.80672.

scholarly journals Identification of TENORM in Zirconium Oxychloride with Gamma Spectrometry

2021 ◽  
Vol 2 (1) ◽  
pp. 61-67
Author(s):  
Kharistya Rozana ◽  
Devi Swasti Prabasiwi ◽  
Dewi Puspa Ariany
Keyword(s):  
Radiation Exposure ◽  
Gamma Spectrometry ◽  
Hpge Detector ◽  
Acid Leaching ◽  
Zirconium Oxychloride ◽  
Environmental Radioactivity ◽  
Gamma Spectrometer ◽  
Activity Concentrations ◽  
Measured Activity ◽  
Job Safety

Abstract: Gamma spectrometer used to determine the type and activity of gamma emitting radionuclides, such as the measurement of TENORM (Th-232, U-238, Ra-26 dan K-40) in the zirconium oxychloride or environmental radioactivity.  This research was carried out to know each the TENORM on the zirconium oxychloride (ZrOCl2.8H2O) which accommodation of environment data the radioactivity in draft job safety about the workers.  Zirconium oxychloride is a result of chloride acid leaching process from sodium zirconate, containing uranium and thorium, so that it has the potential for contamination and increase the radiation exposure.  The instrument used for counting by HPGe detector and the spectrum were analyzed further using software Genie 2000.  Mean measured activity concentrations (radioactivity) of U-238, Th-232, Ra-226 and K-40 respectively were 13,43±0,876 Bq/kg, 12,040±1,483 Bq/kg, 11,400±0,582 Bq/kg dan 32,940±3,270 Bq/kg.

Applying in-Situ and Laboratory-based Gamma Spectrometry to Determine Activity Concentration and Distribution of 40K, 226Ra and 232Th in Abeokuta, Southwest Nigeria

2021 ◽  
Vol 14 (4) ◽  
pp. 323-331
Keyword(s):  
Gamma Spectrometry ◽  
Activity Concentration ◽  
Risk Level ◽  
Primordial Radionuclides ◽  
Activity Concentrations ◽  
Nuclear Security ◽  
Southwest Nigeria ◽  
Average Activity ◽  
The City

Abstract: The applications of radionuclides are potential sources of health risk and also a concern in the area of nuclear security. It is therefore imperative to determine the presence of the different radionuclides present in the environment at all times, because it is necessary to control and assess the risk level in the environment. The present study compares activity concentrations of the primordial radionuclides 40K, 226Ra and 232Th obtained from laboratory gamma spectrometry measurements with the activity concentrations of the radionuclides as obtained from in-situ measurements. Soil samples were randomly collected from nineteen different points within Abeokuta city ensuring good coverage of the city area. A mobile gamma spectrometry system was used to collect gamma spectra measurements in the field. The obtained values are presented. The ranges of activity concentrations for 40K, 226Ra and 232Th have been found to be 113 – 1975, 5 – 128 and 181 – 3284 Bqkg-1, respectively for laboratory gamma spectrometry and 104 – 1312, 31 – 121 and 104 – 2578 Bqkg-1, respectively for in-situ gamma spectrometry measurements. This study showed that the average activity concentrations of the primordial radionuclides in Abeokuta were much higher than worldwide averages of 400, 35 and 30 Bqkg-1 for 40K, 226Ra and 232Th, respectively. From both methods, 232Th is seen to be the major contributor to the environmental radioactivity of Abeokuta. Good correlations also were deduced between the activity concentration results obtained from laboratory and in-situ gamma spectrometry, which therefore implies a significant relationship between the two methods used in the study. Keywords: In-situ gamma, Gamma spectrometry, Activity concentration, Radionuclides.

ASSESSMENT OF NATURALLY OCCURRING RADIONUCLIDES IN MALAYSIA’S BUILDING MATERIALS

2019 ◽  
Vol 186 (4) ◽  
pp. 520-523 ◽  
Author(s):  
Shittu Abdullahi ◽  
Aznan Fazli Ismail ◽  
Supian Samat
Keyword(s):  
Hpge Detector ◽  
Building Materials ◽  
Activity Concentration ◽  
Natural Radionuclides ◽  
Naturally Occurring ◽  
High Purity Germanium ◽  
Activity Concentrations ◽  
Naturally Occurring Radionuclides ◽  
Measured Activity ◽  
Materials Used

Abstract The activity concentrations of 226Ra, 232Th and 40K radionuclides from common building materials used by Malaysian people for construction purposes were studied using High-Purity Germanium (HPGe) detector. The measured activity concentrations of the aforementioned radionuclides range from 10 ± 1 Bq kg−1 (limestone) to 155 ± 61 Bq kg−1 (feldspar), 12 ± 3 Bq kg−1 (limestone) to 274 ± 8 Bq kg−1 (kaolin) and 62 ± 19 Bq kg−1 (limestone) to 1114 ± 20 Bq kg−1 (pottery stone) for 226Ra, 232Th and 40K, respectively. The measured activity concentrations of the natural radionuclides reported herein were found to be in accordance with other previous studies. In general, the activity concentration of the natural radionuclides revealed that all the determined values were below the recommended limit.

scholarly journals Human body prediction of size and shape: a hormonal framework

2019 ◽  
Author(s):  
Jeroen van Vugt
Keyword(s):  
Standard Deviation ◽  
Normal Distribution ◽  
Human Body ◽  
Prediction Accuracy ◽  
Prediction Method ◽  
Future Research ◽  
Least Squares Regression ◽  
Size And Shape ◽  
Log Normal ◽  
Log Normal Distribution

ABSTRACTTo achieve high prediction accuracy with minimal inputs from online retail respondents, a method was developed and tested to predict the size and shape of the human body in 3D using a hormonal framework. The prediction method is based on geometric morphometrics, image analysis, and kernel partial least squares regression. The inputs required are answers to three closed-ended questions and a passport photo. Prediction accuracy was tested with the 3D body scan dataset of the Civilian American and European Surface Anthropometry Resource project. Results from the test dataset showed that approximately 82% of the error expectations of landmarks followed a log-normal distribution with an expectation of 8.816 mm and standard deviation of 1.180 mm. The remaining 18% of the error expectations of landmarks followed a log-normal distribution with an expectation of 18.454 mm and standard deviation of 8.844 mm, which may herald future research. Benchmarked with another method, the proposed method features much less input. In addition to high accuracy, the method in this paper allows for visualisation of results as real-size meshes in millimeters.

scholarly journals Measurements of radon, thoron and their progeny concentrations using twin cup dosimeter for indoor Al-Madaan city – Baghdad – Iraq

2019 ◽  
Vol 14 (30) ◽  
pp. 24-32 ◽  
Author(s):  
Shafik S. Shafik
Keyword(s):  
Lung Cancer ◽  
Effective Dose ◽  
Radon Concentration ◽  
Annual Effective Dose ◽  
Indoor Radon ◽  
Health Hazard ◽  
Health Hazards ◽  
Radon Progeny ◽  
Average Value ◽  
Activity Concentrations

In this study, the activity concentrations of indoor radon, thoronand their progeny have been measured in air for 61 differentlocations of Al-Maddan city using twin cup dosimeter. Furthermore,some useful parameters concerning the health hazards have beenestimated; working level month (WLM), annual effective dose (Eff),and excess lung cancer per million person per year (ELC).The resultsshow that the values of radon gas levels in the investigated districtsvaried from 56.28 to 194.43Bq/m3with an overall average value132.96Bq/m3, while 0.313 to 1.085 for WLM with an overall average0.740, respectively. The value of Eff and ELC have been found tovary from 1.420 to 4.918 mSv/y with an overall average value3.354mSv/y, and 852 to 2951 with an overall average value 2013,respectively. For thoron gas only, the results showed that the thoronactivity concentration varied from 15.05 to 172.40 Bq/m3 with anoverall average 76.48 Bq/m3, and 0.021to 0.240for WLM with anoverall average 0.106, respectively. The values of Eff and ELC havebeen found to vary from 0.256 to 2.94 mSv/y with an overallaverage1.30 mSv/y and from 57 to 652 with an overall average of298, respectively. The concentration of radon progeny varied from59.44 to 301.39 Bq/m3 with an overall average 157.62 Bq/m3. Theresults illustrated that there is a large variation in the values of themeasured concentrations. This is due to the wide variation in theconstruction of the houses in Al-Madaan city. However, allinvestigated locations have radon concentration below the actionlevel (200-300Bq/m3) that recommended byICRP. Therefore, there isno health hazard of radon in the region of Al-Madaan city wheremeasurements have been performed.

scholarly journals Natural radioactivity and external dose assessment of surface soils in Bolikhamxay province, Laos

2017 ◽  
Vol 33 (4) ◽  
Author(s):  
Loat Bui Van
Keyword(s):  
Activity Concentration ◽  
Natural Radionuclides ◽  
Soil Samples ◽  
Dose Assessment ◽  
World Average ◽  
Average Value ◽  
Activity Concentrations ◽  
Radium Equivalent ◽  
The World ◽  
Average Activity

We have determined activity concentrations in 33 soil samples collected from Bolikhamxay Province, Laos. The activity concentrations of the natural radionuclides 226Ra,232Th and 40K in soil samples were measured by a gamma spectrometer with a HPGe detector. The average activity concentrations of the natural radionuclides 226Ra, 232Th and 40K are 43.8 ± 5.6, 57.0 ± 7.3 and 426.4 ± 23.1 Bq.kg-1, respectively. The average activity concentrations of 226Ra and 232Th in this work are higher than those of the world average values. Meanwhile, the  activity concentration of 40 K is almost the same of the world average value. The estimated average outdoor annual effective dose (E) and radium equivalent actitvity (Raeq) are 0.17 ± 0.02 mSv.yr-1 and 154.8 ± 16.1 Bq.kg-1, respectively.

A Method for the Measurement of the Emanation Factor for 222Rn in Small Samples of Porous Materials

1994 ◽  
Vol 56 (1-4) ◽  
pp. 171-173 ◽  
Author(s):  
L.S. Quindos ◽  
P.L. Fernandez ◽  
J. Soto
Keyword(s):  
Physical Properties ◽  
Porous Materials ◽  
Gamma Spectrometry ◽  
Radon Concentration ◽  
Building Materials ◽  
Small Samples ◽  
Activity Concentrations ◽  
Lucas Cell ◽  
Radium Activity

Abstract A method to determine the emanation factor for 222Rn in small samples of soils and building materials is proposed. The method is based on the principle of enclosing the sample to be tested in a hermetically sealed modified Lucas cell, designed and built in our laboratory, and subsequently measuring the radon concentration growth in the cell. The method has been tested for a total of 27 samples with different properties, including soils, building materials and phosphate fertilisers, which were previously evaluated for their physical properties and measured by gamma spectrometry to determine their radium activity concentrations.

scholarly journals A Method for Identification and Assessment of Radioxenon Plumes by Absorption in Polycarbonates

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 8107
Author(s):  
Dobromir Pressyanov ◽  
Pavel Stavrev
Keyword(s):  
Computer Modeling ◽  
Gamma Spectrometry ◽  
Activity Concentration ◽  
Retrospective Evaluation ◽  
Time Intervals ◽  
Activity Concentrations ◽  
Quantitative Estimates ◽  
Consecutive Time ◽  
The Moment ◽  
True Values

A method for the retrospective evaluation of the integrated activity concentration of 133Xe during radioxenon plumes and the moment of the plume’s center is proposed and explored by computer modeling. The concept is to use a specimen of polycarbonate material (a stack of Makrofol N foils of thickness 120 µm and 40 µm in 1 L non-hermetic Marinelly beaker) that is placed in the environment or in a controlled nuclear or radiopharmaceutical facility. On a regular basis or incidentally, the specimen may be retrieved and gamma spectrometry in two consecutive time intervals with durations of 8 h and 16 h is performed. To assess the performance of the method, 133Xe plumes of various integrated activity concentrations and with a duration of up to 10 h are simulated and analyzed, assuming that the measurement starts with a delay of up to one day after the moment of the plume center. It is found that the deviation between the estimates by the method and their true values are within a few percent. Depending on the delay, events of integrated 133Xe activity concentration 250–1000 Bq h m−3 might be qualitatively identified. At levels >10,000 Bq h m−3, the uncertainty of the quantitative estimates might be ≤10%.

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