scholarly journals Characterization of high background radiation of terrestrial naturally occurring radionuclides in a mining region of Senegal

2019 ◽  
Vol 6 (6) ◽  
pp. 472-482
Author(s):  
Mamadou Lamine Sane ◽  
◽  
Modou MBAYE ◽  
Djicknack Dione ◽  
Ahmadou Wague
Keyword(s):  
Background Radiation ◽  
High Background ◽  
Naturally Occurring ◽  
Mining Region ◽  
Naturally Occurring Radionuclides

ASSESSMENT OF NATURAL RADIONUCLIDES LEVELS IN DRINKING WATER FROM OGUN STATE, NIGERIA

2016 ◽  
Vol 78 (6-7) ◽  
Author(s):  
Usikalu M. R. ◽  
Olawole C. O. ◽  
Joel E. S.
Keyword(s):  
Water Samples ◽  
Background Radiation ◽  
Natural Radionuclides ◽  
Age Groups ◽  
Radiological Protection ◽  
Ogun State ◽  
Naturally Occurring ◽  
High Purity Germanium ◽  
Naturally Occurring Radionuclides ◽  
Effective Doses

Naturally occurring radionuclides levels of 238U, 232Th and 40K were investigated in the water samples collected at different boreholes in all the local government of Ogun State using high-purity germanium (HPGe) detector (Canberra Industries Inc.). The activity concentrations measured from the water samples ranged from 0.06 to 1.37 Bq l-1 for 238U, 0.15 to 0.52 Bq l-1 for 232Th and 1.35 to 12.74 Bq l-1 for 40K. The measured activities concentrations for 238U, 232Th and 40K along with their ingested dose conversion factors were used to estimate the annual effective doses in accordance with International Commission on Radiological Protection (ICRP) based on age groups 0 -1y, 1 – 2y, 2 – 7y, 7 – 12y, 12 – 17y and >17y for water consumption. The total annual effective doses calculated varied from 0.004 to 0.517, 0.002 to 0.092, 0.001 to 0.078, 0.001 to 0.076, 0.024 to 0.110 and 0.002 to 0.117 for the age groups accordingly. The physiochemical results showed that 85% of the water was acidic as they have pH less than 6.5 and 65 % of them exceeded the copper concentration recommended limit. It revealed that consumption of the water is safe from natural background radiation for all groups except 0-1 y as the annual effective dose obtained for this group exceeded the average world limit (0.12). The study therefore, suggests that Ogun State populace should use less of these water samples for babies between the age 0-1 year.

scholarly journals Outdoor measurements of thoron progeny in a 232Th-rich area with deposition-based alpha track detectors and corrections for wind bias

2021 ◽  
Author(s):  
Hallvard Haanes ◽  
Hilde Kristin Skjerdal ◽  
Rosaline Mishra ◽  
Anne Liv Rudjord
Keyword(s):  
Half Life ◽  
Noble Gas ◽  
Dose Assessment ◽  
Radioactive Material ◽  
High Background ◽  
Gas Detectors ◽  
Naturally Occurring ◽  
Naturally Occurring Radionuclides ◽  
Thoron Progeny ◽  
Wind Bias

Radon and thoron progeny are important contributors to dose from naturally occurring radionuclides, especially in high background areas and with naturally occurring radioactive material (NORM) legacy sites. Due to the short half-life of thoron, measurements of thoron progeny with a longer half-life should be used for risk and dose assessment. Deposition-based alpha track detectors for such progeny are, however, biased by air movement, especially outdoors where winds may be strong but variable. We used deposition detectors for thoron progeny and radon progeny, as well as alpha track gas detectors for 220Rn and 222Rn, outdoors within the Fen complex in Norway, an area with both elevated levels of naturally occurring radionuclides and NORM legacy sites. Different detector types were used and showed different results. We measured airflow along deposition detectors during deployment to assess wind bias and used statistical models to attain location-specific sheltering factors. These models assess how explanatory terms like point measurements with anemometer, predicted airflow along detectors, and levels of 220Rn and 222Rn explained variation in deposition detector measurements of TnP and RnP. For all the detector types, unrealistically, high equilibrium values (F) were found between progenitor noble gas and progeny before correcting for wind bias. Results suggest a magnitude of wind bias on TnP deposition detectors being a fraction of 0.74–0.96 (mean: 0.87) of the total measurement.

Ensuring the Radiation-Related Ecological Safety of Buildings

2018 ◽  
Vol 878 ◽  
pp. 243-247 ◽  
Author(s):  
I.V. Stefanenko ◽  
O.P. Sidelnikova
Keyword(s):  
Building Materials ◽  
Background Radiation ◽  
Raw Materials ◽  
Natural Radionuclides ◽  
Physical Property ◽  
Human Beings ◽  
Economic Activities ◽  
Naturally Occurring ◽  
Naturally Occurring Radionuclides ◽  
The One

Nowadays, both builders and public have started to pay more and more interest to such a physical property of building materials as radioactivity. This is due to the fact that on the one hand, in the so-called "nuclear era", the problem of reducing radiation doses for people has acquired a global character, and on the other hand - millions of tons of construction raw materials containing natural radionuclides are extracted from bowels and are used in construction, where the structure of these doses of radiation is sharply deformed. Naturally occurring radionuclides make the largest contribution to the dose of human exposure to radiation. Economic activities lead to a significant redistribution of naturally occurring radionuclides in the environment. The background radiation in buildings is considered to be one of the main types of radiation impact on human beings, since people spend a larger part of time indoors. The radiation control of construction objects is necessary to ensure public radiation safety.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

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