A Method to Determine Doublet Photopeak Area 137Cs and 214Bi, in NORM Soil by NaI-detector

2015 ◽  
Vol 5 (2) ◽  
pp. 32-37
Author(s):  
Khairi M.S. Abdullah

Due to the poor resolution of (76 mm×76 mm) NaI scintillation detector, ~7.5% for 137Cs peak (661.5 keV), mutual spectral interference of environmental samples between 137Cs and 214Bi (609 keV) in the decay series of uranium peaks, is a serious problem. This overlapped problem appears in low-level sample spectrum causes overestimation of the specific activity of both nuclides. The main purpose of this work is to resolve this problem and to present a methodology to correct the activity concentrations of 137Cs by NaI(Tl) spectroscopy. In Duhok governorate of Iraq, as a real NORM case, the accumulation of 137Cs is significantly brought by west-north wind and precipitation in the years following nuclear weapons testing and Chernobyl accident in 1986. The developed correlations for any ratio of the measured areas of 214Bi and 137Cs overcome the overestimation and show very good results. The method is approved by comparing the relative error of the measured and corrected activity of Bi with that measured Pb. The maximum, minimum and average relative errors decreased from 40%, 7.3% and 19.4% to 6.1%, -6.5% and 0.6% respectively.

2017 ◽  
Vol 24 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Grzegorz Kosior ◽  
Agnieszka Dołhańczuk-Śródka ◽  
Zbigniew Ziembik

Abstract Mosses are good bioaccumulators of radionuclides and from the 60 of the last century, they are used as bioindicators of radioactive contamination in the environment. Concentration of impurities in moss represent the accumulation in mosses during the past 2-3 years. As a result, the moss composition analysis provides information on an average contamination within a few vegetation seasons. During our survey the measurements of radionuclide activity concentrations in P. schreberi transplanted from places relatively clean to heavily contaminated areas of Upper Silesia were carried out. An increase in the radionuclides activity concentrations in P. schreberi transplants may indicate not only deposition of the radionuclides itself, but also an influx of other pollutants. The results showed no relationship between the Pb-210 activity concentration and activity concentrations of Pb-214, Bi-214, also belonging to the uranium-radium decay series. The increased concentration of Pb-210 in P. schreberi may be the result of the radionuclide atmospheric deposition, which appears in the environment as a result of fossil fuels burning. Excess, allogeneic Pb-210 can be used as marker of environmental pollution. In the areas with its higher activity concentration increased pollution can be expected delivered, for example, by local industry. The Project received financial assistance from the funds of the National Science Centre, granted by force of the decision no. UMO-2013/09/B/NZ8/03340 (NCN).


2021 ◽  
Author(s):  
Mekuanint Lemlem Legasu ◽  
Ashok K Chaubey

Abstract Background & Methodology : The specific activity concentration of naturally occurring radionuclides 226Ra, 232Th, 40K and their health related effects were determined in different environmental samples(gemstones) collected from Delanta-Dawunt. Which is one of the mining place in Ethiopia to extract mainly opals (gemstones). Sample collection and the gamma spectroscopic analysis followed the recommended international procedures for such type of research. Gamma-ray spectrometry was applied using HPGe gamma-ray detector and PC-based MCA. The Purpose of this research: to determine the activity concentrations of the radionuclides U/Th series and K of gemstones(opals), to determine life time cancer risk of radionuclide in the environment , to assess the hazard and risk to the public associated with these dose values , to conduct the geochemical studies by quantifying the levels of trace gemstones as well as the physical parameters in soil samples within and around it, and To determine the radiation doses from these activity concentrations and compare with international recommended dose limits. Results: The results of the activity concentration on our research work showed significant variations from 11.97 ± 2.46 to 62.44 ± 14.99 Bq kg-1 for 226Ra, 25.69 ± 3.69 to 137.84 ± 13.23 Bq kg-1 for 232Th and 184.84 ± 3.59 to 969.56 ±18.16 Bq kg-1 for 40K. The mean radioactivity concentration of 226Ra, 232Th, and 40K was found to be around 29.84 ± 6.53, 68.44 ± 18.94, 390.87 ± 6.09 Bk kg-1 respectively. Conculsion: The mean values of Radium equivalent activity (Raeq), absorbed dose, annual effective dose equivalent, external and internal radiation hazard (Hex and Hin) index ,and activity utilization index is 151.68±19.46 Bq kg-1, 72.19 ± 8.48 nGy h-1, 0.07 ± 0.01mSv y-1,0.43, 0.51, 0.57 ± 0.08 and 0.29 ± 0.03 respectively. The specific activity of 232Th is higher than the world mean value and 40K is the same as the world mean value. The radiation hazard indices, ELCR values found in this study are lower than the world mean values. However, the absorbed dose is higher than the world means value. This is due to the reason of high thorium concentration existence and opal mining is highly explored on such study areas.


2016 ◽  
Vol 8 (1) ◽  
pp. 1472-1478
Author(s):  
Heiyam N. Majeed ◽  
Ali K. Hasan ◽  
Hussein J. Hamad

Al-Najaf Al-Ashraf city one of the most important ,oldest, historical and religious cities in Iraqi country which includes hundreds of holy shrines and historical mosques which over the built hundreds of years. The natural radiation of  forty two  samples of soil which collected randomly in June  2013 from different religious and historical places were  measured using  3"×3" Na(Tl) detection. The mean values activity concentrations of 238U, 232Th and 40K  was ( 23.59±4.37, 12.10±0.54 and 60.68±2.30) Bq kg-1  respectively , specific activity for all soil sample were in the worldwide average. The  average values of the Radium equivalent activity and  annual effective dose  were (22.455 Bq/kg and 25.375 μSv/y) less than the world average .The heist  external and internal hazard and gamma activity concentration index were (0.274 , 0.412 and 0.705) lower than unity.


Author(s):  
Ime Essien ◽  
Akaninyene Akankpo ◽  
Alice Nyong ◽  
Etido Inyang

Natural radioactivity exists in primordial formations such as rocks, soils, water and air where long lived radionuclides such as , ,  and their affiliates are found. This work was done to determine the specific activity of radionuclides, soil to cassava transfer factor and the effective dose due to consumption of radionuclide in cassava products in Ikot Ekpene Local Government Area, Akwa Ibom State. The specific activity of 40K, 238U and 232Th in soils and cassava in   the study area was measured using gamma spectrometry. Mean specific activity in soils ranged from BDL to 153.46 ± 10. 99 Bq/Kg for 40K; BDL to 31. 22 ± 7.49 Bq/Kg for 238U and 1.03 ± 0.10 to 12.71 ± 1.24 Bq/Kg for 232Th. Mean specific activity of the radionuclides in cassava in all  locations ranged from 119.86 ± 8.61 to 601.28 ± 43.23 Bq//Kg for 40K; below detectable limit (BDL) to 15. 89 ± 1.55 Bg/Kg for 238U and BDL to 15. 89 ± 1.55 Bq/kg for 232Th. Transfer factors ranged between 3.64 to 4.18 for 40K; 1.30 to 1.82 for 238U and 0.51 to 0.72 for 232Th.  Effective ingestion dose due to the consumption of cassava from the area ranged between 0.99 mSv/yr to 1.08 mSv/yr and 2.68 mSv/yr to 29.16 mSv/yr for children and adult respectively. Most of the TF and effective ingestion dose results for this study were above the recommended value of unity which suggests that consumption of cassava from the studied area may pose radiological health.


2018 ◽  
pp. 11-18
Author(s):  
Paradee Kodcharin ◽  
Udorn Youngchuay ◽  
Sopa Chinwetkitvanich

This research aims to study the specific activity of natural radioactivity in groundwater samples taken in the area of Phra Nakhon Si Ayutthaya Province, Thailand. Totally, sixty groundwater samples collected from wells in eight districts were monitored and determined for radionuclides 226Ra, 232Th and 40K and gross alpha and beta were determined using high resolution gamma spectrometer and Canberra Tennelec Series 5 gas flow proportional counter, respectively. Most of the sixty wells serve for water consumption and some other wells for agricultural. The results showed that the average activity concentrations of the gross alpha and beta were 0.01±0.007 and 0.15±0.02 Bq L-1 and the specific activity of 226Ra, 232Th and 40K were averagely 0.77±0.13, 1.03±0.19 and 15.56±1.28 Bq L-1, and respectively. The activity concentrations of the gross alpha and beta and the specific activity of the radionuclides in these samples exhibited quite low as compared to the recommended reference level for human consumption reported by World Health Organization (WHO).


2019 ◽  
Vol 26 ◽  
pp. 183
Author(s):  
V. Papakosta ◽  
T. J. Mertzimekis ◽  
M. Triantafyllou

A preliminary study of natural radioactivity was conducted on the thermal spas in Methana Peninsula. To carry out this research, a collection of 17 water samples were taken from thermal springs around and underwater of the volcanogenic Peninsula at depths ranging 0–5 m. The Methana peninsula belongs to the Hellenic Volcanic Arc and is characterized by hydrothermal vent activity. A NaI(Tl) scintillator (AMESOS) was used to carry out gamma–ray counting of the samples to deduce the activity concentrations of the natural radionuclides of the 238U and 232Th decay series, as well as 40K in spa waters. Results are expected to provide information on the geological setting of the Methana peninsula. The impact of naturally occurring radioisotopes to human health has also been assessed in terms of the radiation dose risk corresponding to the measured activities.


Author(s):  
Aline Byrnes ◽  
Elsa E. Ramos ◽  
Minoru Suzuki ◽  
E.D. Mayfield

Renal hypertrophy was induced in 100 g male rats by the injection of 250 mg folic acid (FA) dissolved in 0.3 M NaHCO3/kg body weight (i.v.). Preliminary studies of the biochemical alterations in ribonucleic acid (RNA) metabolism of the renal tissue have been reported recently (1). They are: RNA content and concentration, orotic acid-c14 incorporation into RNA and acid soluble nucleotide pool, intracellular localization of the newly synthesized RNA, and the specific activity of enzymes of the de novo pyrimidine biosynthesis pathway. The present report describes the light and electron microscopic observations in these animals. For light microscopy, kidney slices were fixed in formalin, embedded, sectioned, and stained with H & E and PAS.


1991 ◽  
Vol 66 (04) ◽  
pp. 453-458 ◽  
Author(s):  
John T Brandt

SummaryLupus anticoagulants (LAs) are antibodies which interfere with phospholipid-dependent procoagulant reactions. Their clinical importance is due to their apparent association with an increased risk of thrombo-embolic disease. To date there have been few assays for quantifying the specific activity of these antibodies in vitro and this has hampered attempts to purify and characterize these antibodies. Methods for determining phospholipid-dependent generation of thrombin and factor Xa are described. Isolated IgG fractions from 7 of 9 patients with LAs were found to reproducibly inhibit enzyme generation in these assay systems, permitting quantitative expression of inhibitor activity. Different patterns of inhibitory activity, based on the relative inhibition of thrombin and factor Xa generation, were found, further substantiating the known heterogeneity of these antibodies. These systems may prove helpful in further purification and characterization of LAs.


1990 ◽  
Vol 63 (02) ◽  
pp. 286-290 ◽  
Author(s):  
Christina Beurling-Harbury ◽  
Pehr B Harbury

SummaryActin is the major ATP and ADP binding protein in platelets, 0.9–1.3 nmol/108 cells, 50–70% in the unpolymerized state. The goal of these experiments was to develop a method for extracting all protein-bound ATP and ADP from undisturbed platelets in plasma. Extraction of actin-bound ADP is routine while extraction of actin-bound ATP from platelets in buffer has been unsuccessful. Prior to extraction the platelets were exposed to 14-C adenine, to label the metabolic and actin pools of ATP and ADP. The specific activity was determined from the actin-bound ADP in the 43% ethanol precipitate. Sequential ethanol and perchlorate extractions of platelet rich plasma, and the derived supernatants and precipitates were performed. ATP concentrations were determined with the luciferase assay, and radioactive nucleotides separated by TLC. A total of 1.18 nmol/108 cells of protein-bound ATP and ADP was recovered, 52% ATP (0.61 nmol). The recovery of protein-bound ADP was increased from 0.3 to 0.57 nmol/108 cells. This approach for the first time successfully recovered protein bound ATP and ADP from platelets in a concentration expected for actin.


1978 ◽  
Vol 39 (01) ◽  
pp. 193-200 ◽  
Author(s):  
Erwin F Workman ◽  
Roger L Lundblad

SummaryAn improved method for the preparation of bovine α-thrombin is described. The procedure involves the activation of partially purified prothrombin with tissue thromboplastin followed by chromatography on Sulfopropyl-Sephadex C-50. The purified enzyme is homogeneous on polyacrylamide discontinuous gel electrophoresis and has a specific activity toward fibrinogen of 2,200–2,700 N.I.H. U/mg. Its stability on storage in liquid media is dependent on both ionic strenght and temperature. Increasing ionic strength and decreasing temperature result in optimal stability. The denaturation of α-thrombin by guanidine hydrochloride was found to be a partially reversible process with the renatured species possessing properties similar to “aged” thrombin. In addition, the catalytic properties of a-thrombin covalently attached to agarose gel beads were also examined. The activity of the immobilized enzyme toward fibrinogen was affected to a much greater extent than was the hydrolysis of low molecular weight, synthetic substrates.


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