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In this work, radiological assessment of atmospheric release from Tehran’s Research Reactor (TRR) stack and assessment of public exposures under normal operation has been studied. To perform tasks mentioned above, Pc-Cream computer code which simulates Gaussian Dispersion air transport plume model as well as laboratory analysis of the soil and leaves samples and TLD (Thermo Luminescent Dosimeter) monitoring around the TRR site was used. Results of the Pc- Cream code showed that the annual committed and external dose received by the individual in the vicinity of the reactor is below the regulatory limit. Also, the results of laboratory analysis of available radionuclides in the soil and leaves samples showed that the concentrations are close to the background (K40=635, Th232=28, Cs137=0.29 up to 28.82, Ra226=25 (Bq1/Kg) in soil and K40=457, Be7≈70 (Bq/Kg) in leaves) and confirm the code results. The monitored dose values of the TLD detectors were positioned around the reactor within 500 m radius shows that the background dose in vicinity of TRR (113 μSv up to 150 μSv) is consistent with the background dose in Tehran province (125 μSv).
Mobile forms of radionuclide 137Cs in different soils (natural pastures) of northeastern Poland were evaluated. An attempt was made to show if and what mobile forms of 137Cs are related to different soil properties. For this reason 108 soil samples from 0 to 10 cm in depth were measured for mobile forms of 137Cs activity and analyzed for clay fraction, pH-value, exchangeable potassium (Kex.), exchangeable calcium (Caex.), magnesium (Mgex.), sodium (Naex.) content, organic matter and organic carbon content (C org.), and cation exchange capacity (CEC). Samples of soils were collected in the period from June 1995 to July 1996. The radiocaesium and mobile forms of 137Cs activity were determined by gamma spectrometry. The mobility of 137Cs was studied by means of sequential extraction. Mobile forms of radionuclide l37Cs were related to physicochemical parameters of soils.
The transfer of radionuclide l37Cs from uncultivated different soils (natural pastures) to grass in northeastern Poland was evaluated. Samples of soil and grass were collected from the same area of about 1 m2 in the period from June 1994 to July 1995 twice a year. Grass was sampled from 1 m x 1 m squares by cutting to the plant base. The 137 Cs and 40K activity concentrations were determined by gamma spectrometry. The average concentration of 137Cs (to 10 cm depth) in the studied soils ranged from 17.94 Bq/kg to 37.78 Bq/kg dry weight. The average concentration of radiocesium in grass varied from 1.03 Bq/kg to 12.33 Bq/kg dry weight and depended upon the type of soil.
Nine underground water springs from the Szczawno-Jedlina health resort and one from Zagorze Śląskie were investigated for natural radioactivity content (²²²Rn, ²²⁶,²²⁸Ra, ²³⁸,²³⁴U). In order to obtain the necessary data, two different nuclear spectrometry techniques were applied: a liquid scintillation counter that enabled us to determine ²²²Rn and ²²⁶,²²⁸Ra isotope content, and α spectrometer for measurements of uranium isotopes (²³⁴,²³⁸U) in investigated samples. The activity concentrations of ²²²Rn in investigated samples varied from 6 Bq/l to 227 Bq/l. For radium isotopes the concentrations ranged from 13 mBq/l to 808 mBq/l for ²²⁶Ra and from below 30 mBq/l to 184 mBq/l for ²²⁸Ra. The activity concentrations for uranium isotopes varied from 2.4 mBq/l to 964 mBq/l for ²³⁴U, and from 1.0 mBq/l to 725 mBq/l for ²³⁸U. The isotopic ratios between uranium and radium isotopes (²²⁶Ra/²²⁸Ra, ²²⁶Ra/²³⁸U, ²³⁴U/²³⁸U) and annual effective doses due to these isotopes’ consumption were evaluated. Risk levels due to carcinogenic effects of ²²⁶,²²⁸Ra and ²³⁴,²³⁸U radionuclides consumed with water were estimated.
This paper presents the results of determination of artificial 137cs and natural 40K activity concentrations and some heavy metals in soil samples from the region of one of the main valleys of Tatra National Park (Chochołowska). Our investigation concentrated on 137Cs and heavy metal levels in mountain soil taken from Chochołowska Valley, which revealed great variability in their concentration. The results show con­siderably small amounts of radionuclides 137cs and 40K in the soils. Larger amounts of those elements can be found in the organic surface horizons of the soils. The evaluation of the content of those elements must be based on the bulk density analysis of the soil.
The article presents the results of studies on the content of artificial (¹³⁷Cs, ⁹⁰Sr) and natural radionuclides (²²⁶Ra, ²³²Th, ⁴⁰K) in tissues and organs of various individuals of pumpkinseed Lepomis gibbosus (Linnaeus, 1758) from the Zaporizhzhia (Dnipro) reservoir. It has been revealed that in the bones of sexually mature pumpkinseed females, the content of radionuclides ¹³⁷Cs and⁹⁰Sr is 24.7% and 28.6% less, respectively, than in the bones of males. Summing up the materials of radioecological studies of 2017–2018, the following sequence of tissues and organs of the pumpkinseed by the ability to accumulate radionuclides was obtained: bone> muscle> scales> gills. Research results can be useful for further study on the fish radiation load in the basins of the Dnipro River and during monitoring radioecological research. It was determined that the content of radionuclides in the pumpkinseed muscles did not exceed the permissible levels of radionuclide content for fish as a food product (permissible levels of radionuclide content for ¹³⁷Cs – 150 Bq/kg, ⁹⁰Sr – 35 Bq/kg).
The possibility of using the monoionic Ag+ - form of clinoptilolite of domestic origin for radioactive iodide separation from waters has heen studied. The capacity of the silver form of clinoptilolite towards iodide exceeds many times that of the capacity of clinoptilolite in natural form. Due to low solubility the product Agl iodides generate precipitates on the surface of zeolite. SEM and rtg analyses of the silver form of clinoptilolite after sorption of iodide demonstrate the formation of new crystals on the zeolite surface. In comparison to the origin clinoptilolite sample, TG - analyses show that maximum water release occurs earlier. Sorption of iodide on the silver form of clinoptilolite was described as a second order reaction. The influence of interfering anions on the adsorption capacity of silver clinoptilolite towards iodide was also investigated.
Decontamination effectiveness of ammonium-ferric(lll)-hexacyanoferrate(II) (AFCF) in reducing the radiocaesium transfer into dairy goat milk was examined. The most effective reduction of radioactivity burden in milk was found in animals treated with AFCF as early as the first day of radionuclide contamination. Milk radioactivity concentrations in goats treated simultaneously with ¹³⁷CsCI and hexacyanoferrate were over 10-fold lower than those in the controls at all measurement time points. Decontamination efficiency was reduced when AFCF treatment was delayed.
Studies of the contents of gamma emitters in samples of water and deposit taken from the Bug River (in Poland only) are presented. The total y-activity of deposits ranges from 120-650 Bq/kg and the average value is 350 Bq/kg. The elevated activity is chiefly due to the presence of natural radionuclides. The main artificial radionuclides are Cs-137 and Cs-134, whose contribution to the total activity ranges from 0.2 to 6%. The activity of water samples is low, namely 1.7-3.5 Bq/kg and is due to the presence of natural radionuclides. The heterogeneity of the distribution of natural and artificial radionuclides in the studied samples reveals the effect of economical and industrial activities on contamination of the Bug.
To assess the safety for disposal of radioactive waste-cement composition, the leaching of ⁶⁰Co from a waste composite into a surrounding fluid has been studied. Leaching tests were carried out in accordance with a method recommended by the IAEA. Determination of retardation factors, K F and coefficients of distribution, k d , using a simplified mathematical model for analyzing the migration of radionuclides, has been developed. Results presented in this paper are examples of results obtained in a 30-year mortar and concrete testing project, which will influence the design of the engineered trench system for a future central radioactive waste disposal center.
W pracy prześledzono wpływ czynników stressogennych, takich jak bliskość ciągów komunikacyjnych o różnym natężeniu ruchu, nawożenie jonami tytanu oraz opanowanie przez mszyce Aphis sp. na zawartość radionuklidów w roślinach leczniczych z rodzin Asteracae i Apiaceae. Stwierdzono, że wszystkie badane rośliny zawierają radionuklidy cezu, radu i potasu. Zawartość radu, podobnie jak cezu, w większości prób była niska. Przeprowadzone analizy wykazały, że badane rośliny zawierały znaczne ilości radioaktywnego izotopu potasu. Maksymalne zawartości radionuklidów stwierdzono w próbach pozyskanych ze stanowisk zlokalizowanych przy najruchliwszych drogach. Zaobserwowano, że zastosowane nawożenie jonami tytanu wpłynęło nie tylko na wzrost i rozwój roślin lecz także na zawartość w nich radionuklidów. Odmienna była reakcja poszczególnych organów Pastinaca sativa na opanowanie tej rośliny przez mszyce. Liście roślin kontrolnych gromadziły więcej ²¹⁰Pb niż liście pasternaku na których były mszyce, natomiast korzenie bogatsze były w radioaktywny potas.
Dump consisting of 9500 tons of rich-in-pyrite mining wastes located in the uranium deposit Curilo, Western Bulgaria, was, after rainfall, an intensive source of acid drainage waters. These waters had a pH in the range of about 1.7-4.5 and contained radionuclides (uranium, radium), heavy metals (copper, zinc, cadmium, lead, nickel, cobalt, iron, and manganese), arsenic and sulphates in concentrations usually much higher than the relevant permissible levels for waters intended for use in the agriculture and/or industry. The generation of these polluted waters was studied under real field conditions for a period of about seven years during different climatic seasons. It was found that the dump was inhabited by a diverse microflora in which some acidophilic chemolithotrophic bacteria were the prevalent microorganisms. The solubilization of the above-mentioned pollutants from the dump material was connected mainly with the oxidation of pyrite and other sulphide minerals by these bacteria. Their activity depended on some essential environmental factors such as temperature, pH, and water, oxygen and nutrient contents in the dump.
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