scholarly journals Assessment of radionuclide contamination of plant resources of the Voronezh region by example of leaves of winter linden tree

Author(s):  
N. A. Dyakova

As part of the study, the activity of artificial and natural radionuclides (strontium-90, cesium-137, potassium-40, thorium-232, radium-226) was determined in 36 samples of medicinal plant raw materials of the core and upper soil layers on which the plants were grown. All samples meet the existing requirements of regulatory documentation on radionuclide activity. The average value of the strontium-90 accumulation coefficient was 0.39, in different samples of the region it varied from 0.31 to 0.60. Cesium-137 accumulation coefficients ranged from 0.29 to 0.65 at an average of 0.39. For thorium-232, the average accumulation coefficient in the core lip flowers is 0.15 and took values in the samples studied from 0.09 to 0.231. For potassium-40, the average accumulation ratio in the feed was 0.98 and varied from 0.71 to 1.29, and for radium-226 - 0.47, with a variation from 0.39 to 0.59.

2019 ◽  
pp. 47-52
Author(s):  
Alexander Mikhailovich Okunev

The degree of contamination of the organism of wild animals with radionuclides is of particular importance in the framework of environmental monitoring and assessment of its safety, both for humans and for animals. However, the majority of domestic scientific works on this subject concerns farm animals, and the information relating to hunting animals is much less. This fact determined the relevance of our work, the purpose of which was to study the features of the accumulation of global technogenic and natural radionuclides in the meat of some wild animals in the TRANS-Urals. Experimental data on the content of technogenic radionuclides in the meat of hunting animals were obtained in the autumn-winter periods of 2014 – 2018. Analysis of the average data showed, that the content in the meat of wild animals cesium-137, depending on the animal species, ranged from 4.1 to 49.2; lead-210 – 0,7 – 4,3; and strontium-90 – 0,1 – 1,7 Bq/kg. The total beta- activity of radionuclides in the meat of wild animals varied, depending on the species, from 71.2 to 104.3 Bq/kg. At the same time, all the studied samples of meat corresponded to the norms established by SanPiN-2010 for this type of food product. Some increased accumulation of radioactive cesium (49.2 Bq/kg) and other anthropogenic radionuclides was observed in wild reindeer meat, and in the southern regions of the TRANS-Urals – in bear and wild boar meat (21.1 and 17.4 Bq/kg, respectively). In the muscle tissue of the roe deer the content of this radionuclide was slightly higher than that of the elk (14.7 and 12.2 Bq/kg, respectively). The lowest concentration of cesium-137 (4.1 Bq/kg) and other nuclides was found in beaver meat. The content of strontium-90 in the meat of all tested animals was at a minimum level, and the specific activity of lead-210 was higher than strontium-90 by 2 - 10 times, depending on the species, which indicates the accumulation of this radionuclide in forest ecosystems due to anthropogenic pressure and expansion of the technogenic zone of cities.  The results of studies have shown that differences in the accumulation of technogenic radionuclides in the meat of the hunting animals are largely related to the nature of feeding and composition of the diet of wild species, and are subject to significant fluctuations in accordance with the change in the volume and qualities of food resources in forest biotopes over the year.      


2021 ◽  
Author(s):  
Lubna A. Alasadi ◽  
Ali Abid Abojassim

Abstract The aim from this work is to detect and draw the natural radioactivity of (uranium-238, thorium-232 and potassium-40) levels in soil samples that taken from Kufa districts, Najaf governorate, Iraq. The detection system used in study is NaI (Tl) with "3x3" dimension, while maps were drawn by geographic information system (GIS). Some radiological parameters were calculated depending on measuring of specific activity for 238U, 232Th, and 40K. The results of the average value with standard error in all samples of the present study for 238U, 232Th, 40K, and 235U were 6.2±0.74, 6.41±0.82, 278.10±19.43, and 0.28±0.03 Bq/kg, respectively. The specific activity of Uranium-238, Thourium-232, poasium-40 and Uranium-235 found in all soil samples were within the safety limit reported by UNSCEAR, except three samples have poasium-40 higher than safety limit. Also, the results of radiological parameters were all found to be below OECD, UNSCEAR safety limit. Generally, the average of specific activity in soil collected arranged of potassium-40 > thorium-232 > uranium-238. Mapping GIS for natural radioactivity and some radiological parameters were successfully draw for the study area. Finally, natural radioactivity and radiological parameters for soil samples at Kufa districts were safety.


Purpose. Assessment of bottom sediments accumulation rate for two areas of the Kuyalnyk Estuary using radionuclide method. Methods. The study has been done in two areas of the Kuyalnyk Estuary: the middle part near Kovalivka village and the lower part to the north from the sanatorium, using the standard methods of sediment columns sampling and gamma-spectrometric analysis of radionuclides concentration. Results. Based on the results of the studies of 2016, layer-by-layer concentrations of Cesium-137, Potassium-40, Radium-226 and Torium-232 were determined. Analysis of vertical profiles of Cesium-137 concentrations enabled us to assess, for the first time, the intensity of sediments accumulation in two areas of the estuary for the periods 1962-1986-2016, which later were used for indicative dating of anomalies in the distribution of natural radionuclides Potassium-40, Radium-226 and Torium-232 concentrations. Conclusions. It has been shown that in the lower and middle parts of the Kuyalnyk Estuary the average rate of sediments accumulation in 1986 – 2016 made 0.8±0.1 mm/year and 1.8±0.2 mm/year respectively. In 1962-1986 sediments accumulation rate was practically the same in both parts of the estuary and made 1.9±0. mm/year. The average values for the period 1962-2016 made 1.6±0.1 mm/year and 1.8±0.2 mm/year for the lower and middle parts of the estuary respectively. It has been proposed to perform additional mineralogical studies for more precise dating of the sediment layers accumulated before 1962 and to use radionuclide method for determination of sediment accumulation rate in other water bodies of the Black Sea region.


1977 ◽  
Vol 60 (6) ◽  
pp. 1364-1368
Author(s):  
Robert E Simpson ◽  
Edmond J Baratta ◽  
Charles F Jelinek

Abstract The results are summarized of the analysis for strontium-90, cesium-137, iodine-131, ruthenium-106, and potassium-40, a naturally occurring radionuclide, in samples of total diet and selected import commodities in the foods compliance program of the Food and Drug Administration. On the basis of the radionuclide intake guidelines established by the Federal Radiation Council (FRC), the low content of radionuclides found in the total diet samples for fiscal years 1973 and 1974 demonstrates the need for surveillance only at the present level. The low levels of radionuclides found in a limited number of edible imported commodities indicate that their contribution to the total diet would not increase the levels of these radionuclides above those recommended for only periodic surveillance by the FRC. The potassium levels, determined from potassium-40 activity, found in meats and fish agree with the value for normal muscle tissue for the reference man reported by the International Commission on Radiation Protection. Of the other commodities, nuts contained the highest levels, while sugar, beverages, and processed foods contained the lowest levels of potassium. Although cesium and potassium are chemical analogs with similar metabolic properties, because of their variable content in some leafy samples as a result of surface contamination, a correlation between cesium-137 levels and the cesium-137-to-potassium ratio was inconclusive.


Author(s):  
Abdulwahed Mohamed Aboukarima, Ibrahim Soliman Tabash, Abdul

The study evaluates the hazards of background radiation and Cesium- 137 in the soil of greenhouses within the region of Riyadh, Saudi Arabia. The Mole detector was utilized. It renders readings for the concentration of Uranium- 238, Thorium- 232, Potassium- 40 and Cesium- 137. Field measures were conducted at Alkharj at Nowara Farm Nurseries, Saudi Arabia. Measures were taken at three different greenhouses (plastic covered, glass covered and fiber glass covered). The plants at the plastic- covered greenhouse were cucumber, pepper and eggplant while in the glass and fiber glass- covered greenhouse, the vegetation were ornamental plants and flowers. The average concentration of Uranium- 238 recorded (19.33 Bq/ kg), Thorium- 232 (14.09 Bq/ kg), Potassium- 40 (130.77 Bq/ kg) and Cesium- 137 (1.81 Bq/ kg). These values are less than the world rates. Some radiation hazard indices were also calculated like Radium Equivalent (Raeq), the absorbed dose of Gamma rays in the air, external and internal hazard indices with the purpose of evaluating the dangers of the radiations existing in the greenhouse soil on health. The average radium equivalent activity (Raeq) recorded (49.56 Bq/ kg) which is less than the permissible world rates (370 Bq/ kg). The absorbed dose of Gamma rays in the air recorded (22.94 nGy/ hr) which is again less than the permissible world rates (59 nGy/ h). The average internal and external hazard indices recorded less than one and came within the world permissible limits.


2014 ◽  
Vol 6 (2) ◽  
pp. 1
Author(s):  
Saibatul Hamdi

The purpose of this research is to know the mechanical strength of gypsum board by utilizing waste sawn wood. Raw materials used consist of flour, gypsum,wood particles, boraks and kambang (Goniothalamus sp), wood tarap (Artocarpus elasticus REINW) and lua (Ficus glomerata ROXB). Wood particle 40 mesh and 60 mesh, concentrations boraks of 1 and 2 and the percentage particles of gypsum sawn timber is 300, 400 and 500%. The results showed that the average value Modulus of Rufture (MoR) in lua wood ranges from 12.55 – 14,47 kgcm2, wood kambang 25.10-31,11 kgcm2 and wood tarap 19.20- 24,18 kgcm2. As for Modulus of Elasticity (MoE) on the lua 1129,80- 2092,70 kgcm2, wood kambang 2512,37-3971,32 kgcm2 and tarap 2050,63-2691,09 kgcm2. Gypsum board are mechanical properties do not meet quality standards created SNI 03-6434-2000.Keywords: sawdust, lua, kambang, tarap, gypsum, mechanical


Author(s):  
E. I. Ulyanich ◽  
◽  
Z. I. Kovtuniuk ◽  
V. V. Yatsenko ◽  
O. V. Kuhniuk
Keyword(s):  

2019 ◽  
Vol 46 (6) ◽  
pp. 613-620
Author(s):  
A. P. Chevychelov ◽  
P. I. Sobakin ◽  
L. I. Kuznetsova

Chemical composition of the surface water and the contents of the radionuclides 238U, 226Ra, and 222Rn in water was examined within the natural and man-made landscapes of South Yakutiya. It was demonstrated that intense water migration of these radionuclides from radioactive dump pits of the man-made landscapes of the Elkonsky uranium-ore district, which were created during the process of wide-scale exploration surveys for radioactive raw materials conducted during the last third of the 20th century, had occurred. Currently, the areas of water dissipation of 238U and 226Ra are detected at a distances of 2 km and greater from the source of the radioactive contamination along the outflow vector.


2020 ◽  
Vol 299 ◽  
pp. 37-42
Author(s):  
O.A. Fomina ◽  
Andrey Yu. Stolboushkin

A model of the transition layer between the shell and the core of a ceramic matrix composite from coal waste and clay has been developed. The chemical, granulometric and mineral compositions of the beneficiation of carbonaceous mudstones and clay were studied. The technological and ceramic properties of raw materials for the samples manufacturing were determined. The method of manufacturing multilayer ceramic samples from coal waste, clay and their mixture is given. The number of transition layers in the contact zone between the clay shell and the core from coal wastes is determined. The deformation and swelling phenomena of model samples from coal wastes, clay, and their mixtures were revealed at the firing temperature of more than 1000 °C. The formation of a reducing ambient in the center of the sample with insufficient air flow is shown. The influence of the carbonaceous particles amount and the ferrous form iron oxide in the coal wastes on the processes of expansion of multilayer samples during firing has been established.


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