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Sample records for artificial radionuclides behavior

  1. Leaching of artificial radionuclide out of minerals

    International Nuclear Information System (INIS)

    Bogdanov, R.V.; Osipova, I.V.; Sergeev, A.S.

    1992-01-01

    Leaching of radionuclides induced by neutron bombardment in natural silicates and silicophosphate of rare earth elements and calcium, is studied using gamma-spectrometry. It is shown that solution of minerals under the effect of artificial subsoil water at 75 deg C is incongruent character: difference in leaching of cobalt and actinides reaches value equal to two magnitudes. Behaviour of lanthanides as analogs of transplutonium elements is of special interest. Essential role of specimen microphase composition is pointed out. The suggested methodological approach is efficient at selection of matricies for fixaton of radioactive wastes

  2. Water, soil, crops and radionuclides. Studies on the behavior of radionuclides in the terrestrial environments

    International Nuclear Information System (INIS)

    Uchida, Shigeo

    2008-01-01

    In order to predict the migration of artificially-produced radionuclides into a human body and its radiation dose rates of human body and to decrease the exposed radiation doses of human body, the behavior of radionuclides in the environment must be elucidated. In National Institute of Radiological Sciences (NIRS), the environmental radioecological research group of Nakaminato Laboratory for Marine Radioecology has progressed the survey and research on the behavior of artificially-produced radionuclides in the terrestrial environment. This article describes the research results (the radioactivity of water, soil, and crops) made so far at Nakaminato Laboratory for Marine Radioecology. (M.H.)

  3. Artificial radionuclides in soil, flora and fauna

    International Nuclear Information System (INIS)

    Marej, A.N.

    1984-01-01

    Sources and ways of soil contamination by radionuclides, as well as the main regularities of radionuclide behaviour in soils, are discussed. Ways of radionuclide uptake by plants are discussed in detail, since radionuclide contamination of vegetation, and agricultural plants and pastures in particular, is one of the main factors, determining sanitary value of environmental contamination by radioactive substances

  4. Radionuclide power source for artificial heart autonomic apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lazarenko, Yu V; Gusev, V V; Pustovalov, A A

    1988-02-01

    Works on creating autonomous artificial heart devices with radionuclide heat source are described. Calculated and experimental parameters of /sup 238/Pu base radionuclide thermoelectric RITEG generators designed for supplying perspective blood pump electric drives are presented. RITEG structure is described and the prospects of increasing its efficiency are shown.

  5. Radionuclide behavior at underground environment

    International Nuclear Information System (INIS)

    Hahn, Phil Soo; Park, Chung Kyun; Keum, Dong Kwon; Cho, Young Hwan; Kang, Moon Ja; Baik, Min Hoon; Hahn, Kyung Won; Chun, Kwan Sik; Park, Hyun Soo

    2000-03-01

    This study of radionuclide behavior at underground environment has been carried out as a part of the study of high-level waste disposal technology development. Therefore, the main objectives of this project are constructing a data-base and producing data for the safety assessment of a high-level radioactive waste, and verification of the objectivity of the assessment through characterization of the geochemical processes and experimental validation of the radionuclide migration. The various results from the this project can be applicable to the preliminary safety and performance assessments of the established disposal concept for a future high-level radioactive waste repository. Providing required data and technical basis for assessment methodologies could be a direct application of the results. In a long-term view, the results can also be utilized as a technical background for the establishment of government policy for high-level radioactive waste disposal

  6. Radionuclide behavior at underground environment

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Phil Soo; Park, Chung Kyun; Keum, Dong Kwon; Cho, Young Hwan; Kang, Moon Ja; Baik, Min Hoon; Hahn, Kyung Won; Chun, Kwan Sik; Park, Hyun Soo

    2000-03-01

    This study of radionuclide behavior at underground environment has been carried out as a part of the study of high-level waste disposal technology development. Therefore, the main objectives of this project are constructing a data-base and producing data for the safety assessment of a high-level radioactive waste, and verification of the objectivity of the assessment through characterization of the geochemical processes and experimental validation of the radionuclide migration. The various results from the this project can be applicable to the preliminary safety and performance assessments of the established disposal concept for a future high-level radioactive waste repository. Providing required data and technical basis for assessment methodologies could be a direct application of the results. In a long-term view, the results can also be utilized as a technical background for the establishment of government policy for high-level radioactive waste disposal.

  7. Radionuclide behavior in the environment

    International Nuclear Information System (INIS)

    Tveten, U.

    1991-09-01

    The purpose of this report is to document the results of the following task: Review for quality and consistency the available data on measurements of initial ground contamination of Chernobyl radionuclides in various parts of Norway and subsequent concentrations of these radionuclides in various environmental media as functions of time. Utilize the data obtained to verify the existing models, or to improve them, for describing radionuclide behavior in the environment. Some of the processes standard were: migration into soil; weathering; resuspension; food-chain contamination; and loss or reconcentration by run-off. The task performed within this contract has been to use post-Chernobyl data from Norway to verify or find areas for possible improvement in the chronic exposure pathway models utilized in MACCS. Work has consisted mainly of collecting and evaluating post-Chernobyl information from Norway or other countries when relevant; but has also included experimental work performed specifically for the current task. In most connections the data available show the models and data in MACCS to be appropriate. A few areas where the data indicate that the MACCS approach is faulty or inadequate are, however, pointed out in the report. These should be examined carefully, and appropriate modifications should eventually be made. 14 refs., 12 figs., 22 tabs

  8. Radionuclide behavior at underground environment

    International Nuclear Information System (INIS)

    Hahn, Phil Soo; Park, Chung Kyun; Keum, Dong Kwon; Cho, Young Hwan; Kang, Moon Ja; Baik, Min Hoon; Hahn, Kyung Won; Park, Hyun Soo

    2003-04-01

    This study of radionuclide behavior at underground environment has been carried out as a part of the study of high-level waste disposal technology development. Therefore, the main objectives of this project are constructing a data-base and producing data for the safety assessment of a high-level radioactive waste, and verification of the objectivity of the assessment through characterization of the geochemical processes and experimental validation of the radionuclide migration. This project is composed of 6 subjects such as data production required for safety assessments, sorption properties and mechanisms, nuclide migration in the fractured rock, colloid formation and migration, nuclide speciation in deep geological environments, and total evaluation of geochemical behaviors considering multi-factors. The various results from the this project can be applicable to the preliminary safety and performance assessments of the established disposal concept for a future high-level radioactive waste repository. Providing required data and technical basis for assessment methodologies could be a direct application of the results. In a long-term view, the results can also be utilized as a technical background for the establishment of government policy for high-level radioactive waste disposal

  9. Artificial radionuclides in the atmosphere over Lithuania

    International Nuclear Information System (INIS)

    Lujaniene, G.; Sapolaite, J.; Remeikis, V.; Lujanas, V.; Aninkevicius, V.

    2006-01-01

    Systematic observations of radionuclide composition and concentration in the atmosphere have been carried out at the Institute of Physics in Vilnius since 1963. An increase in activity concentration of radionuclides in the atmosphere was observed after nuclear weapon tests and the Chernobyl NPP accident. At present the radiation situation in Lithuania is determined by two main sources of radionuclides, forest fire and resuspension products transferred from highly polluted region of the Ukraine and Belarus. During forest fires the increase in activity concentration of 1 37Cs in the atmosphere was registered in many countries and in Lithuania as well. This work summarizes the experimental data on transport of cesium, plutonium, americium from the highly contaminated territories after the Chernobyl accident. The activity concentrations of 1 37Cs were measured in two - three days samples while plutonium and americium in monthly samples. In addition, the analyses of the events of the increase activity concentration, meteorological situation, speciation of radionuclides and mechanisms of formation and transformation of aerosol carriers of radionuclides are presented. Aerosols were sampled on perchlorvinyl filters and the large volume air samplers with a flow rate from 2400 m 3 /h to about 6000 m 3 /h were used. The radiochemical analyses of monthly samples of aerosol ashes (about 30 g) were performed. For separation of Pu isotopes the TOPO/cyclohexane extraction and radiochemical purification using UTEVA resin were performed, Am was separated after TOPO/cyclohexane extraction using TRU and TEVA resins (100-150 μm). 2 42Pu and 2 43Am were used as tracers in the separation procedure. The alpha spectrometry measurements of Pu and Am isotopes deposited on a stainless steel disc were carried out with the Alphaquattro (Silena) spectrometer. 1 37Cs was determined by gamma-ray spectrometry using the high purity HPGe detector (resolution - 1.9 keV/1.33 Mev, efficiency - 42

  10. Binding and release of artificial radionuclides in sediments

    International Nuclear Information System (INIS)

    Foerstner, U.; Schoer, J.

    1980-01-01

    Artificial radionuclides in aquatic systems are generally associated with more labile solid phases than are their stable counterparts. This implies that special attention must be paid to the possible effects on the biological uptake of artificial isotopes from contamined dredged materials following deposition or land application. An estimation of possible effects could be made from chemical extraction experiments similar to those already applied to stable heavy metal isotopes. Within the aquatic system the changes of the physico-chemical conditions, such as pH-values, oxygen content, salinity, and the concentration of complexing organic substances, may effect a partial remobilization of artificial radionuclides from the solids, which occurs more readily than with the respective stable isotopes. (orig.) [de

  11. HUMAN EXPOSURE TO THE ARTIFICIAL RADIONUCLIDES IN ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ivana Vukanac

    2012-09-01

    Full Text Available Artificial radionuclides are product of different human activities and their presence in the environment is negative side effect of civilization progress. They have been spread in the environment by events such as nuclear weapon tests, nuclear accidents and by deliberate and negligent discharge of radioactive waste from nuclear and other installation. Once released in to the nature, the artificial radionuclides start to circle in the same manner as naturally occurring ones, and finally they fall out from air and water onto the ground and build into the foodstuff and drinking water resulting in radiation doses to human beings. The short overview of presence of artificial radioactivity in human environment and its impact on human life is presented in this paper.

  12. HUMAN EXPOSURE TO THE ARTIFICIAL RADIONUCLIDES IN ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ivana Vukanac

    2012-09-01

    Full Text Available Artificial radionuclides are product of different human activities and their presence in the environment is negative side effect of civilization progress. They have been spread in the environment by events such as nuclear weapon tests, nuclear accidents and by deliberate and negligent discharge of radioactive waste from nuclear and other installation. Once released in to the nature, the artificial radionuclides start to circle in the same manner as naturally occurring ones, and finally they fall out from air and water onto the ground and build into the foodstuff and drinking water resulting in radiation doses to human beings. The short overview of presence of artificial radioactivity in human environment and its impact on human life is presented in this paper

  13. Multigated radionuclide study of the total artificial heart

    Energy Technology Data Exchange (ETDEWEB)

    Datz, F L; Christian, P E; Taylor, A Jr; Hastings, W L; De Vries, W C

    1987-07-01

    A permanent total artificial heart, the Jarvik-7, was implanted into a 61-year-old male with a severe cardiomyopathy. Gated radionuclide studies were performed in the patient both prior to surgery and following implantation. Preoperative gated radionuclide cardiac studies revealed marked left ventricular enlargement, severe hypokinesis and a left ventricular ejection fraction of 10%. The right ventricle was moderately enlarged with a 27% ejection fraction. Following implantation of the Jarvik-7 artificial heart, gated cardiac studies were performed with a computer gated by a signal from the heart controller. The left ventricular ejection fraction was 69% and the right ventricular ejection fraction was 62%. This compared to a theoretical ejection fraction of 74% for each ventricle based on chamber anatomy. There was excellent ventricular emptying. Phase analysis showed uniform diaphragm motion. The use of gated cardiac studies in humans may prove helpful in evaluating mechanical problems with the artificial heart, such as manlfunction of the diaphragm, before they become clinically apparent.

  14. Artificial Radionuclides Database in the Pacific Ocean: HAM Database

    Directory of Open Access Journals (Sweden)

    Michio Aoyama

    2004-01-01

    Full Text Available The database “Historical Artificial Radionuclides in the Pacific Ocean and its Marginal Seas”, or HAM database, has been created. The database includes 90Sr, 137Cs, and 239,240Pu concentration data from the seawater of the Pacific Ocean and its marginal seas with some measurements from the sea surface to the bottom. The data in the HAM database were collected from about 90 literature citations, which include published papers; annual reports by the Hydrographic Department, Maritime Safety Agency, Japan; and unpublished data provided by individuals. The data of concentrations of 90Sr, 137Cs, and 239,240Pu have been accumulating since 1957–1998. The present HAM database includes 7737 records for 137Cs concentration data, 3972 records for 90Sr concentration data, and 2666 records for 239,240Pu concentration data. The spatial variation of sampling stations in the HAM database is heterogeneous, namely, more than 80% of the data for each radionuclide is from the Pacific Ocean and the Sea of Japan, while a relatively small portion of data is from the South Pacific. This HAM database will allow us to use these radionuclides as significant chemical tracers for oceanographic study as well as the assessment of environmental affects of anthropogenic radionuclides for these 5 decades. Furthermore, these radionuclides can be used to verify the oceanic general circulation models in the time scale of several decades.

  15. Multigated radionuclide study of the total artificial heart

    International Nuclear Information System (INIS)

    Datz, F.L.; Christian, P.E.; Taylor, A. Jr.; Hastings, W.L.; De Vries, W.C.

    1987-01-01

    A permanent total artificial heart, the Jarvik-7, was implanted into a 61-year-old male with a severe cardiomyopathy. Gated radionuclide studies were performed in the patient both prior to surgery and following implantation. Preoperative gated radionuclide cardiac studies revealed marked left ventricular enlargement, severe hypokinesis and a left ventricular ejection fraction of 10%. The right ventricle was moderately enlarged with a 27% ejection fraction. Following implantation of the Jarvik-7 artificial heart, gated cardiac studies were performed with a computer gated by a signal from the heart controller. The left ventricular ejection fraction was 69% and the right ventricular ejection fraction was 62%. This compared to a theoretical ejection fraction of 74% for each ventricle based on chamber anatomy. There was excellent ventricular emptying. Phase analysis showed uniform diaphragm motion. The use of gated cardiac studies in humans may prove helpful in evaluating mechanical problems with the artificial heart, such as manlfunction of the diaphragm, before they become clinically apparent. (orig.)

  16. Artificial neural networks application for horizontal and vertical forecasting radionuclides transport

    International Nuclear Information System (INIS)

    Khil'ko, O.S.; Kovalenko, V.I.; Kundas, S.P.

    2010-01-01

    Artificial neural networks approach for horizontal and vertical radionuclide transport forecasting was proposed. Runoff factors analysis was considered. Additional artificial neural network structures for physical-chemical properties recognition were used. (authors)

  17. Dose assessment on natural radiation, natural radionuclide, and artificial radionuclide released by Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Hosoda, Masahiro; Tokonami, Shinji; Furukawa, Masahide

    2012-01-01

    Various radionuclides are distributed in environmental materials such as soil, rock, and water. People are exposed every day to natural radiation. According to the UNSCEAR 2008 report, Sources of Ionizing Radiation, natural radiation sources are categorized as terrestrial gamma-rays, radon, cosmic rays and food. The effective dose from radon, thoron and its decay products is about 50% of all natural radiation exposure. Consciousness of the Japanese public toward radiation exposure has significantly increased since the start of the Fukushima Dai-ichi Nuclear Power Station accident. In this paper, the nationwide survey and dose estimation for terrestrial gamma-rays and radon are summarized. External dose from artificial radionuclides released by the Fukushima accident are also reported. (author)

  18. Behavior acquisition in artificial agents

    OpenAIRE

    Thurau, Christian

    2006-01-01

    Computational skill acquisition in robots and simulated agents has been a topic of increasing popularity throughout the last years. Despite impressive progress, autonomous behavior at a level of animals and humans are not yet replicated by machines. Especially when a complex environment demands versatile, goal-oriented behavior, current artificial systems show shortcomings. Consider for instance modern 3D computer games. Despite their key role for more emersive game experience, surprisingly l...

  19. First artificial radionuclides for Czechoslovakia after Word War II. Pt. 1

    International Nuclear Information System (INIS)

    Tesinska, Emilie

    2014-01-01

    This first contribution in the 2-part series describes the following topics: Discovery of artificial radioactivity and first artificial radionuclides; Czechoslovak reflection of the development over the world; Opportunities for obtaining artificial radioisotopes from the USA; Response to the US offer by Czechoslovak physicians; and Steps taken by the Ministry of Health. (orig.)

  20. [The distribution of artificial radionuclides in the biomass of macrophytes of the Yenisei River].

    Science.gov (United States)

    Zotina, T A

    2009-01-01

    The Yenisei River is contaminated with artificial radionuclides due to the operation of the Mining-and-Chemical Combine (MCC), Rosatom, producing weapon grade plutonium for several decades. Artificial radionuclides including activation isotopes and transuranics, are detected in the biomass of submerged aquatic plants of the river. We investigated the distribution of artificial radionuclides in the biomass of macrophytes from radioactively contaminated part of the Yenisei River with chemical fractionation techniques. Artificial radionuclides were detected in extracellular and intracellular compartments of the macrophytes. The distribution of radionuclides among the biomass fractions differed essentially. 54Mn was preferably in mobile, exchangeable form compared to other isotopes. Essential portion of 137Cs was in non exchangeable form. Significant activity of artificial radionuclides was detected in the particles of suspended matter of the river, attached to the plant surfaces. Radioactive isotopes were distributed among biomass fractions similar to stable isotopes. The distribution of potassium and 137Cs differed essentially. On the basis of the results obtained the assumptions on the further migration of radionuclides accumulated by aquatic macrophytes in the Yenisei River have been done.

  1. The results of artificial radionuclides monitoring in the Baltic sea

    International Nuclear Information System (INIS)

    Astrauskiene, N.; Lukinskiene, M; Zemaitiene, G.

    1994-01-01

    Long-term radionuclides volume activity (v.a.) monitoring (1976-1990) data showed that measurement results obtained in steady observation station give reliable information of the coastal area of the Baltic sea radioactive equilibrium between atmosphere and surface water was observed in the coastal zone. Chernobyl Power Plant accident influenced upon the Baltic sea coastal water by radionuclides 137 Cs and 144 Ce. Radionuclide 90 Sr volume activity was practically unchangerable. The mechanism of radionuclides fallout from atmosphere are various. lt can be illustrated by 137 Cs and 144 Ce a.v. structure field variations in open sea and coastal zone near Juodkrante. The Baltic sea inhomogeneous contamination by radionuclide 137 Cs in 1988-1990 leads to equalization of 137 Cs v.a. in the surface waters and it causes v.a. increase in coastal waters. (author)

  2. Distribution of natural and artificial radionuclides in chernozem soil/crop system from stationary experiments.

    Science.gov (United States)

    Sarap, Nataša B; Rajačić, Milica M; Đalović, Ivica G; Šeremešić, Srđan I; Đorđević, Aleksandar R; Janković, Marija M; Daković, Marko Z

    2016-09-01

    The present paper focuses on the determination of radiological characteristics of cultivated chernozem soil and crops from long-term field experiments, taking into account the importance of distribution and transfer of radionuclides in the soil-plant system, especially in agricultural cropland. The investigation was performed on the experimental fields where maize, winter wheat, and rapeseed were cultivated. Analysis of radioactivity included determination of the gross alpha and beta activity as a screening method, as well as the activities of the following radionuclides: natural ((210)Pb, (235)U, (238)U, (226)Ra, (232)Th, (40)K, (7)Be) and artificial ((90)Sr and (137)Cs). The activities of natural and artificial ((137)Cs) radionuclides were determined by gamma spectrometry, while the artificial radionuclide (90)Sr was determined by a radiochemical analytical method. Based on the obtained results for the specific activity of (40)K, (137)Cs, and (90)Sr, accumulation factors for these radionuclides were calculated in order to estimate transfer of radionuclides from soil to crops. The results of performed analyses showed that there is no increase of radioactivity that could endanger the food production through the grown crops.

  3. The effects of radionuclides on animal behavior

    International Nuclear Information System (INIS)

    Gagnaire, B.; Adam-Guillermin, C.; Bouron, A.; Lestaevel, P.

    2011-01-01

    to increased suicides, as well as modification of preferred nesting sites, reduced hatching success and fecundity in birds that live in the Chernobyl zone. No significant effect from caesium exposure was shown in laboratory experiments with rats, but few studies were conducted. Data on radioactive cadmium are not available in the literature, but the effects of its metallic form have been well studied. Cadmium induces mental retardation and psychomotor alterations in exposed populations and increases anxiety in rats, leading to depression. Cadmium exposure also results in well-documented effects on feeding and burrowing behavior in several invertebrate species (crustaceans, gastropods, annelids, bivalves) and on different kinds of fish behavior (swimming activity, fast-start response, anti-predatory behavior). Cobalt induces memory deficits in humans and may be involved in Alzheimer's disease; gamma irradiation by cobalt also decreases fecundity and alters mating behavior in insects. Collectively, data are lacking or are meagre on radionuclide pollutants, and a better knowledge of their actions on the cellular and molecular mechanisms that control animal behavior is needed. (authors)

  4. Establishment and application of a large calibration device of artificial radionuclide plane source

    International Nuclear Information System (INIS)

    Hu Mingkao; Zhang Jiyun; Wang Xinxing; Zhang Sheng

    2010-01-01

    With the expansion of the application fields of nuclear techniques and the development of economy, more and more airborne/vehicle and other large γ spectrometers are applied in the environment radiation monitoring of artificial radioactive nuclides. In order to ensure the reliability of the monitoring results, a large calibration device of artificial radionuclide plane source is established. The paper introduces the device's built history and the results of application. (authors)

  5. Inventory and application of artificial radionuclides in France

    International Nuclear Information System (INIS)

    Besson, J.P.; Hoorelbeke, A.

    1998-01-01

    A number of regulations were completed with the aim to ensure safe storage and application of radionuclides in France, especially taking into account radiation protection. CIREA guarantees their unanimity by its judgement on the general questions arising from application of regulations. It has a regulatory role since it requires special conditions for particular practices. Authorisation for induction of radioactive sources or equipment containing sources, their application, storage, etc. are directly given by CIREA or after having obtained its premises

  6. Natural and artificial radionuclides in southern of Gulf of Mexico marine sediments

    International Nuclear Information System (INIS)

    Rodriguez-Espinosa, P.F.; Vidal-Lorandi, V.M.V.; Vidal-Lorandi, F.V.

    1999-01-01

    Preliminary results of quantitative analysis of natural and artificial radionuclides in sediment cores of the Southern Gulf of Mexico, reveal the presence of 22.01 Bq/kg 226 Ra, 15.56 Bq/kg 214 Bi, 18.17 Bq/kg 214 Pb, 485.81 Bq/kg 40 K and 2.84 Bq/kg 137 Cs

  7. Radionuclides distribution in artificial reservoir V-17 (old swamp)

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmenkova, N. [Vernadsky Institute of geochemistry and analytical chemistry RAS (Russian Federation); Vlasova, I.; Sapozhnikov, Y.; Kalmykov, S. [Lomonosov MSU, Chemistry Dep. (Russian Federation); Pryakhin, E. [Urals Research center for radiation medicine (Russian Federation); Ivanov, I. [FSUE Mayak PA (Russian Federation)

    2014-07-01

    Reservoir V-17 (Old Swamp) was formed as a result of the construction of dams in 1952 and 1954 (MAYAK Production Association),located in a natural depression relief. Intermediate level liquid radioactive wastes (ILLW) have been discharged to this reservoir since 1949. The water surface area of the lake is 0.13 km{sup 2} with the volume of 0.36 Mm{sup 3}. The maximum depth is 6.5 m with the average value of 2.8 m. Among 74 PBq deposited to the reservoir, the major portion is concentrated in the bottom sediments (as determined in 2007). The aim of this study is to determine radionuclide distribution among abiotic and biotic aquatic components, that includes study of various radionuclides distribution between water and bottom sediments, their speciation and evaluation of condition of zooplankton community. As a result of field research at the reservoir, 4 sampling locations were chosen from which bottom sediments, water samples and some hydrobionts were collected. Pore waters were separated from the wet sediments by high-speed centrifugation. All samples were analyzed by gamma spectrometry using HPGe detector Canberra GR 3818.The radioactivity of tritium in the pore and lake waters was determined by liquid-scintillation spectrometry. The strontium-90 was detected by Cherenkov counting of the daughter {sup 90}Y. The preliminary data show for sediments samples: for {sup 137}Cs amount varies from 75,5 KBq/g to 232 KBq/g, {sup 154}Eu - from 460 to 990 Bq/g, {sup 241}Am - from 1 to 4 KBq/g, {sup 134}Cs - from 50 to 220 Bq/g; for water samples: large contribution from strontium-90 and tritium (varies from 2 to 25 Bq/g). Pore water contains medium amount of radionuclides between sediments and water samples. For {sup 137}Cs varies between 160 to 1100 Bq/g, {sup 154}Eu - from 0,1 to 0,3 Bq/g, {sup 241}Am - from 0,3 to 11 Bq/g, {sup 134}Cs - from 0,1 to 1,7 Bq/g. Variation depends on the sampling place. Activity distribution among hydrobionts was studied by digital Radiography

  8. Natural and artificial radionuclides in soils from Parana State, Brazil

    International Nuclear Information System (INIS)

    Schuch, L.A.; Barreto, W.O.; Cardoso, A.

    1994-01-01

    Soil samples from Parana State, Brazil, were collected in 1991 and compared with others collected at some location in March 1977 and at the end of 1983. Pedological analyses were practiced on the samples and 137 Cs and 232 Th, 226 Ra and 40 K activities were determined by gamma-ray spectrometry. A latitude dependence of 137 Cs was found as well. It was impossible to determine the 137 Cs contribution from Chernobyl nuclear accident because of low fallout and intense leaching, erosion and re-suspension in soils of regions with high annual precipitation. Natural radionuclides did not show such effects. (author) 39 refs; 6 tabs

  9. State of contamination of French food produces by artificial radionuclides

    International Nuclear Information System (INIS)

    Boursier, B.; Guiard, A.; Tesolin, B.; Janin, F.

    1994-01-01

    This study presents the results of 40236 recorded levels of caesium 134 Cs and 137 Cs activities carried out on French food. These controls, performed through gamma-spectrometry, have been carried out in France by the Veterinary Services and the CNEVA-LCHA (Centre National d'Etudes Veterinaires - Laboratoire Central d'Hygiene Alimentaire), as part of a radionuclides survey after the Chernobyl accident. The results have been collected by the CNEVA-LCHA, and show in 1992 that 99.6% of the radioactivity levels in the French food are below 50 Bq/kg. The present situation seems to be satisfying. However, very small amounts of 137 Cs residues were noticed in some mushroom species, such as Cantharellus tubaeformis. (authors). 3 figs., 1 tab

  10. Bioconcentration of artificial radionuclides in edible mushrooms: in situ and in vitro studies

    Energy Technology Data Exchange (ETDEWEB)

    Dementyev, Dmitry V.; Manukovsky, Nikolai S.; Bolsunovsky, Alexander Ya.; Alexandrova, Yuliyana V. [Institute of Biophysics, Siberian Branch of the Russian Academy of Sciences, 660036, Krasnoyarsk (Russian Federation)

    2014-07-01

    Some areas of the Yenisei River basin are affected by the operation of the Mining-and-Chemical Combine (MCC), producing weapons-grade plutonium. Flood plain soils of the Yenisei contain a wide range of artificial radionuclides, including transuranium elements, which can be accumulated by living organisms. Concentrations of artificial radionuclides and heavy metals accumulated by mushrooms may be several orders of magnitude higher than those accumulated by plants, and, thus, mushrooms may be used as bio-concentrators of radionuclides and heavy metals for bioremediation of contaminated areas. The purposes of this study were to investigate 1) species specificity of accumulation of artificial radionuclides by edible mushrooms in radioactively contaminated areas of the Yenisei River flood plain and 2) accumulation rates of artificial radionuclides, including transuranium elements, in mushrooms under laboratory conditions. Species specificity of accumulation of artificial radionuclides and uranium by mushrooms was analyzed for 12 species of edible mushrooms. The study was performed at the sites affected by MCC operation, which were divided into two groups: 1) the sites only affected by aerosol-bound radionuclides and 2) the sites that also received waterborne radionuclides. Field studies showed great interspecific variations in Cs-137 accumulation by mushrooms. Activity concentrations of Cs-137 in bioindicator species Suillus granulatus and S. Luteus reached 10 kBq/kg dry weight. S. granulatus and S. luteus are concentrators of Cs-137, as suggested by the analysis of concentration factors (CFs), which reached 0.7-16 for these mushroom species. The CF of U-238 in fruiting bodies of the mushrooms was no greater than 0.11. Yenisei flood plain soils contain a wide range of transuranium elements, which can accumulate in environmental objects. Laboratory experiments on accumulation of Am-241 from solution by mycelium and Am-241 accumulation by fruiting bodies of mushrooms

  11. Distribution of artificial radionuclides in deep sediments of the Mediterranean Sea

    International Nuclear Information System (INIS)

    Garcia-Orellana, J.; Pates, J.M.; Masque, P.; Bruach, J.M.; Sanchez-Cabeza, J.A.

    2009-01-01

    Artificial radionuclides enter the Mediterranean Sea mainly through atmospheric deposition following nuclear weapons tests and the Chernobyl accident, but also through the river discharge of nuclear facility effluents. Previous studies of artificial radionuclides impact of the Mediterranean Sea have focussed on shallow, coastal sediments. However, deep sea sediments have the potential to store and accumulate pollutants, including artificial radionuclides. Deep sea marine sediment cores were collected from Mediterranean Sea abyssal plains (depth > 2000 m) and analysed for 239,240 Pu and 137 Cs to elucidate the concentrations, inventories and sources of these radionuclides in the deepest areas of the Mediterranean. The activity - depth profiles of 210 Pb, together with 14 C dating, indicate that sediment mixing redistributes the artificial radionuclides within the first 2.5 cm of the sedimentary column. The excess 210 Pb inventory was used to normalize 239,240 Pu and 137 Cs inventories for variable sediment fluxes. The 239,240 Pu/ 210 Pb xs ratio was uniform across the entire sea, with a mean value of 1.24 x 10 -3 , indicating homogeneous fallout of 239,240 Pu. The 137 Cs/ 210 Pb xs ratio showed differences between the eastern (0.049) and western basins (0.030), clearly significant impact of deep sea sediments from the Chernobyl accident. The inventory ratios of 239,240 Pu/ 137 Cs were 0.041 and 0.025 in the western and eastern basins respectively, greater than the fallout ratio, 0.021, showing more efficient scavenging of 239,240 Pu in the water column and major sedimentation of 137 Cs in the eastern basin. Although areas with water depths of > 2000 m constitute around 40% of the entire Mediterranean basin, the sediments in these regions only contained 2.7% of the 239,240 Pu and 0.95% of the 137 Cs deposited across the Sea in 2000. These data show that the accumulation of artificial radionuclides in deep Mediterranean environments is much lower than predicted by

  12. Simulation of radionuclide chemistry and sorption characteristics in the geosphere by artificial intelligence technique

    International Nuclear Information System (INIS)

    Liu Shangjyh; National Tsing Hua Univ., Hsinchu; Wang Shigang; Ho Liwei

    1988-01-01

    An expert system operated in a personal computer is employed to simulate chemistry and sorption phenomena of radionuclides in the geosphere. The system handles both qualitative and quantitative analyses primarily for the actinides and fission products. The system also incorporates data bases of several groundwater and rock types with mineral and chemical compositions, the distribution coefficients of nuclides for minerals, etc. The decision rule base facilitates this system to carry out the reasoning procedures to predict the solubility-limiting phase, solute species, oxidation states and possible complex formations of radionuclides, as well as to calculate the distribution coefficients and retardation factors in a geological formation, provided that the essential groundwater and host rock information are available. It is concluded that this device of artificial intelligence provides a vehicle to accumulate developed human knowledge and serves as a tool not only for simulating the complicated radionuclide behaviour in the geosphere, but also for instructional or educational purpose in this field. (orig.)

  13. Behaviors of radionuclides in wet underground soil

    International Nuclear Information System (INIS)

    Inoue, Y.; Morisawa, S.

    Experimental studies were made of the variations of the distribution coefficient of 65 Zn, 60 Co, and /sup 110 m/Ag with Ca ion contents in sand--water and resin--water systems. It is concluded that: (1) The distribution coefficient of a radionuclide is not constant but varies greatly especially with calcium ion concentration in underground water. (2) The Saturation Index I=pH-pHs can be used as a parameter to indicate such variations. (3) Some radionuclides, existing as radiocolloids like (sup 110m/Ag and 59 Fe, are inactive toward ion exchange reactions as with hydroxide. In such cases, the nuclides migrate underground as fast as underground water

  14. Behaviour and fate of artificial redionuclides in the marine environment

    International Nuclear Information System (INIS)

    1979-01-01

    Behaviour of artificial radionuclides in the marine environment, effect of the physico-chemical forms of the radionuclides. Behavior of radionuclides in the physical and biological environments and general evaluation of transfers [fr

  15. Experimental evaluation of admission and disposition of artificial radionuclides including transuranium elements in agricultural plants

    Energy Technology Data Exchange (ETDEWEB)

    Kozhakhanov, T.; Lukashenko, S. [Institute of radiation safety and ecology (Kazakhstan)

    2014-07-01

    Processes of radionuclides migration and transfer to agricultural plants are quite well developed worldwide, but the information on character of accumulation of {sup 241}Am and {sup 239+240}Pu transuranium radionuclides in agricultural plants is still fragmentary. Even in generalized materials of worldwide studies, IAEA guide, accumulation coefficient (AC) can have wide range of values (5-6 orders), no data exists on radionuclides' distribution in different organs of plants and they are given for joined groups of plants and types of soils. That is why the main aim of this work was to obtain basic quantitative parameters of radionuclides' migration in 'soil-plant' system, and firs of all- for transuranium elements.. In 2010 a series of experiments with agricultural plants was started at the territory of the former Semipalatinsk Test Site aimed to investigate entry of artificial radionuclides by crop products in natural climatic conditions. To conduct the experiment for study of coefficient of radionuclides' accumulation by agricultural corps, there was chosen a land spot at the STS territory, characterized by high concentration of radionuclides: {sup 241}Am - n*10{sup 4} Bq/kg, {sup 137}Cs - n*10{sup 3} Bq/kg, {sup 90}Sr - n*10{sup 3} Bq/kg and {sup 239+240}Pu- n*10{sup 5} Bq/kg. As objects of investigation, cultures, cultivated in Kazakhstan have been selected: wheat (Triticum vulgare), barley (Hordeum vulgare), oat (Avena sativa L.), water melon (Citrullus vulgaris), melon (Cucumis melo), potato (Solanum tuberosum), eggplant (Solanum melongena), pepper (Capsicum annuum), tomato (Solanum lycopersicum), sunflower (Helianthus cultus), onion (Allium cepa), carrot (Daucus carota), parsley(Petroselinum vulgare)and cabbage (Brassica oleracea). Investigated plants have been planted within the time limits, recommended for selected types of agricultural plants. Cropping system included simple agronomic and amelioration measures. Fertilizers were not

  16. Behavior of radionuclides in sanitary landfills.

    Science.gov (United States)

    Chang, K C; Chian, E S; Pohland, F G; Cross, W H; Roland, L; Kahn, B

    1984-01-01

    his study was undertaken to evaluate the possibility of disposing low-level radioactive waste in sanitary landfills with leachate containment to prevent environmental releases. To meet this objective, two simulated landfills, each 200 l. in volume and containing 55 kg of municipal refuse, were operated in the laboratory with simulated rainfall additions for a 9-month period to observe the extent to which radio-cobalt, -cesium, -strontium and tritium were leached into the liquid phase. One of the units was operated with leachate recycle, the other as a single pass control. Liquid samples were analyzed weekly for 3H, 58Co, 85Sr and 134Cs tracers. Weekly analyses were also performed for approximately 30 parameters to define the degree of stabilization of the waste. Major parameters included BOD, COD, pH and concentrations of specific organics, metals and gases. Concentrations of stable cobalt, strontium and cesium were also measured periodically. Soluble radioactivity levels in both systems were reduced by factors of 50 for 58Co, 5 for 85Sr and 7 for 134Cs, taking radioactive decay and dilution into account. Some radionuclide removal from the liquid phase was associated with major chemical changes in the landfills that occurred within 80 days for the control system and within 130 days for the recycle unit. Observed acid, sulfide, and CO2 concentrations suggested mechanisms for removing some of the radionuclides from leachate. Detection of 3H in the off-gas indicated that less than 1% of tritiated waste became airborne. The waste in the leachate recycle unit was more completely stabilized than in the control unit.

  17. A field study of physico-chemical states of artificial radionuclides in seawater

    International Nuclear Information System (INIS)

    Nagaya, Yutaka; Nakamura, Kiyoshi

    1974-01-01

    The physico-chemical states of artificial radionuclides, 90 Sr, 137 Cs and 144 Ce in seawater were investigated by radiochemical analysis of filtered and unfiltered seawater. The difference of radionuclide concentrations between unfiltered and filtered seawaters was defined as the ''particulate form'' radioisotope and its ''particle ratio'' was discussed. Practically no particulate 90 Sr, greater than 0.22 μ in size, was observed in both coastal and open seawaters, but some of 137 Cs seemed to be insoluble in some circumstances, especially in coastal waters. A considerable amount of 144 Ce was found to be particulate. An estimation of the radionuclides in particulate form was made for Kashima-nada seawaters collected in 1970 to 1972, and it was shown that the possible occurrence of particulate radionuclides, greater than 0.22 μ in size, were 1% or less for 90 Sr and 6% for 137 Cs. In the coastal water, 80% of 144 Ce were seemed to be in particulate form, but in the open seawater only a few %. The influences of suspended materials to 137 Cs and 144 Ce concentration levels in seawater were not negligible and further investigations are desirable. (auth.)

  18. Depositional history of artificial radionuclides in the Ross Ice Shelf, Antarctica

    International Nuclear Information System (INIS)

    Koide, M.; Michel, R.; Goldberg, E.D.; Herron, M.M.; Langway, C.C. Jr.

    1979-01-01

    The annual fluxes of artificial radionuclides ( 238 Pu, sup(239 + 240)Pu, 241 Am, 137 Cs, 90 Sr and 3 H) from the atmosphere to the Ross Ice Shelf in Antarctica were determined from measurements in strata dated by 201 Pb. Recognizable sources include the U.S tests (Mike-Ivy and Castle Hill) in the early 1950s, the U.S.S.R. tests of the early 1960s, the SNAP-9A burnup of 1964 and the French and Chinese tests in the late 1960s and 1970s. There are several problems still awaiting resolution: the differences in atmospheric chemistries of fission products and of transuranics produced in weapons tests and the anomalous fluxes of 238 Pu to the ice shelf which do not appear to reflect a one-year stratospheric residence. There is no evidence for a smearing of the fallout record as a consequence of diffusion of these radionuclides in the glacial column. (Auth.)

  19. Preliminary results on accumulation and loss of artificial radionuclides in marine benthic algae

    International Nuclear Information System (INIS)

    Santos, P.L. dos; Santos Gouvea, R.C.; Gusmao Pedrini, A.

    1978-01-01

    The acummulation and the loss of artificial radionuclides in three species of marine benthic algae of the state of Rio de Janeiro were studied under laboratory conditions, so that a selection of biological indicators for radioctive contamination of the marine environment could be made. Medium concentration factors were calculated, the most significant figures being those obtained for the algae Pterocladia Capillacea (Gmelin) Bornet et Thuret (132+-40) p/ sub(131) I and Sargassum vulgares J. Agardh (19+-5) p/ 51 Cr [pt

  20. Natural and artificial radionuclides in the Suez Canal bottom sediments and stream water

    International Nuclear Information System (INIS)

    El-Tahawy, M.S.; Farouk, M.A.; Ibrahiem, N.M.; El-Mongey, S.A.M.

    1994-01-01

    Concentration of natural and artificial radionuclides in Suez Canal bottom sediments and stream water have been measured using γ spectrometers based on a hyper-pure Ge detector. The activity concentrations of 238 U series, 232 Th series and 40 K did not exceed 16.0, 15.5 and 500.0 Bq kg -1 dry weight for sediments. The activity concentration of 238 U series and 40 K did not exceed 0.6 and 18.0 Bq l -1 for stream water. (author)

  1. Natural and artificial radionuclides in the Suez Canal bottom sediments and stream water

    Science.gov (United States)

    El-Tahawy, M. S.; Farouk, M. A.; Ibrahiem, N. M.; El-Mongey, S. A. M.

    1994-07-01

    Concentration of natural and artificial radionuclides in Suez Canal bottom sediments and stream water have been measured using γ spectrometers based on a hyper-pure Ge detector. The activity concentrations of 238U series, 232Th series and 40K did not exceed 16.0, 15.5 and 500.0 Bq kg-1 dry weight for sediments. The activity concentration of 238U series and 40K did not exceed 0.6 and 18.0 Bq 1-1 for stream water.

  2. Development of the design of standardized units for the production of artificial radionuclides

    International Nuclear Information System (INIS)

    Auger, J.P.

    1976-01-01

    The production of artificial radionuclides began more than 20 years ago and has seen continuous growth at the rate over 20% a year. Technology has had to be adapted constantly to this growth in order to guarantee production and at the same time ensure the safety of personnel. The Department, which started its career in underground workings at Chatillon and then moved to the Saclay hot laboratories, is now housed in a building designed specially for the production of artificial radionuclides and equipped with standard production units. The first generation of standard units was sufficient to handle production which had begun to grow. Subsequently, thanks to the experience gained, there came into being a second generation of standardized units perfectly adapted to the new production requirements. The paper describes the evolution of design solutions between the first and the second standard, relating to contained cells, cell containment, remote control, interchangeability of cells, ventilation, waste discharge systems and repair of internal equipment. A highly positive evaluation can be made of the experience gained from the present standard. (author)

  3. Determination of natural and artificial radionuclides in 3 earner ecosystems (Alcocebre; Vinaroz and Vandellos)

    International Nuclear Information System (INIS)

    Navarro, E.; Roldan, C.; Sanchez, E.

    1998-01-01

    The knowledge of the environmental radioactivity level represents one of the main objectives at the moment for the environmental investigation. To check the existence of possible polluting sources and their impact in the population is of high-priority interest. We have intended to check the existence or not of radioactive pollutants in bio-indicators (algae, limpets and mussels) of the marine environment of three towns located in the Mediterranean coast: Alcocebre and Vinaroz in the county of Castellon and Vandellos in the county of Tarragona where a nuclear group is located for electric power production. The specific activity measurement carried out during the biennium 1996-97 of the natural gamma emitters ''228 Ac (''232Th series), ''226Ra (''238U series), ''235U, ''40K and ''7Be, and of the artificial radionuclides ''60Co, and ''137 Cs, it corroborates the character bio-accumulator of these organisms. Natural and artificial radionuclides have been detected in quantities without radiological significance. (Author) 3 Refs

  4. Prominent artificial radionuclide activity in the environment of coastal Karnataka on the southwest coast of India

    Energy Technology Data Exchange (ETDEWEB)

    Narayana, Y. [Department of Studies in Physics, Mangalore University, Mangalagangotri-574 199 (India)]. E-mail: narayanay@yahoo.com; Somashekarappa, H.M.; Karunakara, N.; Avadhani, D.N.; Mahesh, H.M.; Siddappa, K. [Department of Studies in Physics, Mangalore University, Mangalagangotri-574 199 (India)

    2000-09-01

    Studies on radiation level and radionuclide distribution in the environment of coastal Karnataka were undertaken to provide baseline data for the future assessment of the impact of the nuclear and thermal power stations that are being set up in the region and to understand the behaviour of radionuclides in the environment. As part of the programme the concentrations of two important artificial radionuclides, namely {sup 90}Sr and {sup 137}Cs, have been measured in a number of environmental samples. The concentration of {sup 90}Sr is very low in most of the samples. Among the samples analysed for the concentration of {sup 137}Cs, soil samples showed elevated levels of activity in some sampling stations. Among the vegetables, brinjal (Solanum melongena. L) showed considerable activity. The internal dose due to intake of {sup 90}Sr through diet was 0.42 {mu}Sv year{sup -1} for the vegetarian population and 0.32 {mu}Sv year{sup -1} for the non-vegetarian population. The internal dose due to dietary intake of {sup 137}Cs was found to be 0.34 {mu}Sv year{sup -1} and 0.26 {mu}Sv year{sup -1} respectively for the vegetarian and non-vegetarian population. The results are discussed in the light of the literature values reported for other environs of India and abroad and appropriate inferences are drawn. (author)

  5. A model to predict the level of artificial radionuclides in environmental materials in the Severn Estuary and the Bristol Channel

    International Nuclear Information System (INIS)

    McColl, N.P.

    1988-01-01

    The NRPB SEVERN compartment model, of the Bristol Channel and Severn Estuary, has been developed for used in predicting environmental concentrations of artificial radionuclides present in the estuary. A comparison between predicted and measured values of salinity and environmental 137 Cs concentrations has demonstrated the overall validity of the model. SEVERN has been used to assess the radiological impact of radionuclides present in the estuary which result from low-level routine discharges from the nuclear power industry. (author)

  6. Vibration behavior of the artificial barrier system

    International Nuclear Information System (INIS)

    Mikoshiba, Tadashi; Ogawa, Nobuyuki; Nakamura, Izuru

    2000-01-01

    This study aims at production of a mimic specimen of artificial barrier, experimental elucidation of influence of seismic motion due to a vibration experiment on the artificial barrier system, and establishment of an evaluating method on its long-term behavior. The study has been carried out under a cooperative study of the National Research Institute for Earth Science and Disaster Prevention and the Japan Nuclear Cycle Development Institute. In 1998 fiscal year, an artificial barrier specimen initiated by crosscut road was produced, and their random wave and actual seismic wave vibrations were carried out to acquire their fundamental data. As a result of the both vibrations, it was found that in a Case 2 specimen of which buffer material was swelled by poured water, the material was integrated with a mimic over-pack to vibrate under judgement of eigen-frequency, maximum acceleration ratio, and so forth on the test results. And, in a Case 1 specimen, it was thought that the mimic over-pack showed an extreme non-linear performance (soft spring) because of reducing eigen-frequency with increase of its vibration level. (G.K.)

  7. Vibration behavior of the artificial barrier system

    Energy Technology Data Exchange (ETDEWEB)

    Mikoshiba, Tadashi; Ogawa, Nobuyuki; Nakamura, Izuru [National Research Inst. for Earth sceince and Disaster Prevention (Japan)

    2000-02-01

    This study aims at production of a mimic specimen of artificial barrier, experimental elucidation of influence of seismic motion due to a vibration experiment on the artificial barrier system, and establishment of an evaluating method on its long-term behavior. The study has been carried out under a cooperative study of the National Research Institute for Earth Science and Disaster Prevention and the Japan Nuclear Cycle Development Institute. In 1998 fiscal year, an artificial barrier specimen initiated by crosscut road was produced, and their random wave and actual seismic wave vibrations were carried out to acquire their fundamental data. As a result of the both vibrations, it was found that in a Case 2 specimen of which buffer material was swelled by poured water, the material was integrated with a mimic over-pack to vibrate under judgement of eigen-frequency, maximum acceleration ratio, and so forth on the test results. And, in a Case 1 specimen, it was thought that the mimic over-pack showed an extreme non-linear performance (soft spring) because of reducing eigen-frequency with increase of its vibration level. (G.K.)

  8. Distribution of some artificial and natural radionuclides and trace elements in Syrian soils

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Shaik Khalil, H.; Amin, Y.; Ibrahim, S.; Hassan, M.

    2004-07-01

    Within the environmental monitoring program in Syria, about 115 surface soil and 38 profile soil samples were collected and analyzed during the period of 1998 to 2003 in order to determine the levels of natural and artificial radionuclides and some of trace elements (Cu, Zn, Cd, Pb). The concentrations of the natural radionuclides in the surface samples were found to vary from area to another and ranged from 2-50 Bq/kg, 4-228 Bq/kg, 4-55 Bq/kg, 1-143 Bq/kg and 96-672 Bq/kg for 224 Ra, 226 Ra, 228 Ra, 137 Cs and 04 K, respectively. While, the concentrations of the studied trace elements were varied between 0.5-5.6 mg/kg for U, 3.2-31.7 mg/kg for Pb, 14-141 mg/kg for Zn, 1.6-114 mg/kg for Cu and 0.25-2.7 mg/kg for Cd. Most of the reported values in this study were in the range of the natural uncontaminated surface soil concentrations and published values in many countries in the world. The results showed that the relation between the distribution of the natural radionuclides and depth was approximately the same for all radionuclides except for 137 Cs, which was extremely binded in the upper layers of soil. In addition, some differences in the concentrations of the studied trace elements with depth were observed. These differences may be due to the average of rainfall and the existence of some potential sources of contamination of such elements. However, the results of this study can be considered as a database for the natural background in Syria that helps to establish the radiation map of the country.(author)

  9. Radionuclide transport behavior in a generic geological radioactive waste repository.

    Science.gov (United States)

    Bianchi, Marco; Liu, Hui-Hai; Birkholzer, Jens T

    2015-01-01

    We performed numerical simulations of groundwater flow and radionuclide transport to study the influence of several factors, including the ambient hydraulic gradient, groundwater pressure anomalies, and the properties of the excavation damaged zone (EDZ), on the prevailing transport mechanism (i.e., advection or molecular diffusion) in a generic nuclear waste repository within a clay-rich geological formation. By comparing simulation results, we show that the EDZ plays a major role as a preferential flowpath for radionuclide transport. When the EDZ is not taken into account, transport is dominated by molecular diffusion in almost the totality of the simulated domain, and transport velocity is about 40% slower. Modeling results also show that a reduction in hydraulic gradient leads to a greater predominance of diffusive transport, slowing down radionuclide transport by about 30% with respect to a scenario assuming a unit gradient. In addition, inward flow caused by negative pressure anomalies in the clay-rich formation further reduces transport velocity, enhancing the ability of the geological barrier to contain the radioactive waste. On the other hand, local high gradients associated with positive pressure anomalies can speed up radionuclide transport with respect to steady-state flow systems having the same regional hydraulic gradients. Transport behavior was also found to be sensitive to both geometrical and hydrogeological parameters of the EDZ. Results from this work can provide useful knowledge toward correctly assessing the post-closure safety of a geological disposal system. © 2014, National Ground Water Association.

  10. Behaviors and chemical forms of radionuclides in seawater

    International Nuclear Information System (INIS)

    Honda, Yoshihide

    1981-01-01

    Although the radionuclides introduced into the marine environment from various sources and routes are finally distributed among the components of the marine ecosystem, the residence time is one of the most useful measures of the reactivity of an element in the oceanic chemical system. Heavy metals such as Mn, Fe, Co and Zn which have shorter residence times, reveal more complicated behaviours in relation to marine radioecological interest than alkaline earth element such as Sr which has a longer residence time. The possible physico-chemical forms of radionuclides in the oceans are usually classified into three categories, that is, species in true solution, colloidal species, and particulate forms. The modeling to study the dispersion of radionuclides introduced into the marine environment can be approached with the aid of the knowledge of behaviors of their stable counterparts in seawater. The different physico-chemical forms between stable and radioactive nuclides in seawater may cause different biological concentration of the element. To realize the chemical speciation of radionuclides in the marine environment, it is also important in thermodynamical calculation to consider heterogeneous interfaces where cause raising the concentration of reactants in seawater, especially in the coastal waters. In the discussion on the primary factors that can affect the elemental distribution in the marine environment, primary productivity and bacterial activity are emphasized for the transformation of physicochemical states of radionuclides in the marine environment. Finally, the radioecological differences between radiocobalt in organic complexed and ionic forms were demonstrated in the experiments on the uptake and elimination of radiocobalt by mussels. (J.P.N.)

  11. The presence of some artificial and natural radionuclides in a Eucalyptus forest in the south of Spain

    International Nuclear Information System (INIS)

    Vaca, F.; Manjon, G.; Garcia-Leon, M.

    2001-01-01

    Long-lived artificial radionuclides ( 137 Cs, 90 Sr) were studied in a Eucalyptus plantation located in the south-west of Spain. Radionuclide concentrations were determined in different types of samples corresponding to specific forest components (soil, trees, herbs and litter). Depth profile distributions were obtained in two selected core soils. Two layers were separately measured in three other cores. The concentration factor, defined as the ratio between the mean activity concentration in a component and the mean activity concentration in the soil, was calculated for each component. The biomass of different components was estimated in order to evaluate the total density concentration (Bq/ha) of the artificial radionuclides ( 137 Cs, 90 Sr) in the Eucalyptus plantation. The transfer of the radionuclides between the different forest components can be inferred from the results. Additionally, other naturally occurring radionuclides ( 40 K, 226 Ra, 228 Ra, 228 Ac) were determined for comparison. Transport of radionuclides from forest to a nearby pulp mill is also discussed

  12. Natural and artificial radionuclides in forest and bog soils: tracers for migration processes and soil development

    International Nuclear Information System (INIS)

    Schleich, N.; Degering, D.; Unterricker, S.

    2000-01-01

    Radionuclide distributions in undisturbed forest and bog soils, mostly situated in Saxony, Germany (Erzgebirge), were studied. Low concentrations of naturally-occurring U and Th decay series nuclides, including 210 Pb, and artificial radioisotopes ( 125 Sb, 134 Cs, 137 Cs, 241 Am) were determined using low-level γ-spectrometry. In addition, the activities of 238 Pu and 239,240 Pu were determined by radiochemical separation and α-spectrometry. 14 C and excess 210 Pb dating methods were used to date the sampled bog profiles. The different radionuclides show characteristic depth distributions in the forest and bog soil horizons, which were sub-sampled as thin slices. 125 Sb, 241 Am, 238 Pu and 239,240 Pu are strongly fixed in soil organic matter. In spruce forest soils, the influence of soil horizons with distinct properties dominates the vertical time-dependent distribution. In ombrotrophic bogs, the peak positions correlated with the year of maximum input of each nuclide. The Sb, Am and Pu ''time markers'' and the 14 C and 210 Pb dating results correspond very well. Although Cs seems to be relatively mobile in organic as well as mineral forest soil horizons, it is enriched in the organic material. In ombrotrophic bogs, Cs is very mobile in the peat deposit. In Sphagnum peat, Cs is translocated continuously towards the growing apices of the Sphagnum mosses, where it is accumulated. (orig.)

  13. Use of aquatic mosses for monitoring artificial radionuclides downstream of the nuclear power plant of Bugey (River Rhone, France)

    International Nuclear Information System (INIS)

    Beaugelin-Seiller, K.; Brottet, D.

    1994-01-01

    The detection of radionuclides in water, downstream of nuclear installations located on river banks, is often very difficult notably because of their low concentrations. Thus the use of biological indicators is an interesting process to detect radioactive contamination of an aquatic ecosystem. From 1986 to 1990, artificial radionuclides were measured in freshwater mosses sampled downstream of the nuclear power station of Bugey. These field data on the whole, have shown a comparatively good qualitative and quantitative relationship between radioactive composition of liquid waste and radionuclides detected in mosses. In other respects, the results showed up a relatively clear hierarchical structure in the affinity of the different radionuclides for the mosses. To specify these relations, mesh bags containing allochtonous mosses were immersed at four stations downstream of the power plant and regularly sampled during a 10-h waste discharge period. (author)

  14. Problems of dynamics radionuclides behavior in environment of Belarus

    International Nuclear Information System (INIS)

    Basharin, A.V.; Matveev, S.A.; Pushkareva, T.L.; Sharovarov, G.A.

    2003-01-01

    The experience of various methods application for radionuclide contaminated objects after the Chernobyl accident is considered. Methods useful to different objects, including kindergartens, are defined as a result of analysis. Methods of observation and control 134,137 Cs, 90 Sr and 238-240 Pu behavior in various environments are described. Value of the second air pollution after extraordinary situation at contaminated territories and object 'Ukryttia' is given. Dates of post-Chernobyl contamination of rivers and soils with radiocesium and radiostrontium, as well as deactivation of social objects are generalized

  15. Application of two-barrier model of radioactive agent transport in sea water for analyzing artificial radionuclide release from containers with radioactive waste dumped in Kara Sea

    Energy Technology Data Exchange (ETDEWEB)

    Grishin, Denis S.; Laykin, Andrey I.; Kuchin, Nickolay L.; Platovskikh, Yuri A. [Krylov State Research Center, Saint Petersburg, 44 Moskovskoe shosse, 196158 (Russian Federation)

    2014-07-01

    Modeling of artificial radionuclide transport in sea water is crucial for prognosis of radioecological situation in regions where dumping of radioactive waste had been made and/or accidents with nuclear submarines had taken place. Distribution of artificial radionuclides in bottom sediments can be a detector of radionuclide release from dumped or sunk objects to marine environment. Proper model can determine the dependence between radionuclide distribution in sediments and radionuclide release. Following report describes two-barrier model of radioactive agent transport in sea water. It was tested on data from 1994 - 2013 expeditions to Novaya Zemlya bays, where regular dumping of solid radioactive waste was practiced by the former USSR from the early 1960's until 1990. Two-barrier model agrees with experimental data and allows more accurate determination of time and intensity of artificial radionuclide release from dumped containers. (authors)

  16. Comparative analysis of the mobility of uranium and artificial radionuclides in the ecosystem of the Yenisei River

    Energy Technology Data Exchange (ETDEWEB)

    Bolsunovsky, Alexander; Medvedeva, Marina [Institute of Biophysics SB Russian Academy of Sciences, 660036, Krasnoyarsk (Russian Federation)

    2014-07-01

    The Yenisei River is one of the largest rivers in the world, which had been subjected to radioactive contamination for over 50 years, due to operation of the Mining-and-Chemical Combine (MCC) of Rosatom at Zheleznogorsk, which had been producing weapons-grade plutonium. Bottom sediments and flood plain of the Yenisei River are contaminated by artificial radionuclides, including transuranium ones, both close to the MCC and at a considerable distance downstream. The MCC is also a source of uranium isotopes in the Yenisei. Thus, the Yenisei River basin is a unique environment for studying the mobility of both uranium isotopes and artificial radionuclides in all components of the aquatic ecosystem. The purpose of this study was to compare the mobility of uranium and artificial radionuclides in the ecosystem of the Yenisei River. Samples of water, sediments, and aquatic organisms were used as study material. Aquatic organisms were represented by submerged plants, benthic-feeding fish, and zoo-benthos. The submerged plants (macrophytes) analyzed were of five species: Fontinalis antipyretica, Potamogeton lucens, Ceratophyllum demersum, Myriophyllum spicatum, and Elodea canadensis. Grayling (Timalus arcticus) represented benthic-feeding fish, and zoo-benthos species were represented by Philolimnogammarus viridis, which forms the major part of the grayling's diet. Samples were collected at positions in the vicinity of the MCC discharge point, at a distance of 110 km downstream of Krasnoyarsk, and upstream of the MCC, during sampling campaigns in 2008-2012. Radionuclide measurements were performed using a wide range of instrumental methods: gamma-spectrometry with a 'Canberra' spectrometer (U.S.), mass spectrometry with an 'Agilent' spectrometer (U.S.), neutron activation analysis, and beta-alpha radiometry. The results obtained in this study suggest that the part of the Yenisei River ecosystem contaminated due to MCC radioactive discharges contains

  17. The relationship of mineral and geochemical composition to artificial radionuclide partitioning in Yenisei river sediments downstream from Krasnoyarsk.

    Science.gov (United States)

    Bondareva, Lydia

    2012-06-01

    Discharges from the Mining-and-Chemical Combine (MCC) of Rosatom, downstream from Krasnoyarsk, resulted in radioactive contamination of sediments of the River Yenisei. The concentration of artificial gamma-emitting radionuclides ((137)Cs, (60)Co, (152)Eu, and (241)Am) was determined with the objective to analyze the migration processes leading to the transport of these radionuclides. The content of artificial radionuclides in the surface layers of the study area varied in wide ranges: (137)Cs-318-1,800 Bq/kg, (60)Co-87-720 Bq/kg, (152)Eu-12-287 Bq/kg and (241)Am-6-76 Bq/kg. There was a sequence of migration of radionuclides investigated in the surface layer of sediments that were collected in the near zone of influence of the MCC: (241)Am ≈ (152)Eu > (60)Co > (137)Cs. Radionuclide species have been found to be directly related to sediment structure and composition.

  18. Processes engaged in the persistence in atmosphere of previously deposited artificial radionuclides

    International Nuclear Information System (INIS)

    Piga, Damien

    2010-01-01

    Since 1959, atmospheric sampling stations of the environmental radioactivity permanent observatory measure both natural and artificial radioactivity in ambient air. Nowadays, Cs-137 (30.07 years), an artificial radionuclide mainly issue from atmospheric weapons tests and several accidents, is still measured at trace level in the lower atmosphere although there is no significant release anymore. The aim of this study was to identify and characterize the processes which explain this persistence. Areas highly contaminated by Chernobylsk accident are the major contributors to the Cs-137 atmospheric persistence in France. In these areas, wildfires are the most significant resuspension processes during the dry season and can lead to long range transport events. Around 1013 Bq of Cs-137 are yearly resuspended by this process. In connection with significant increases of total suspended particles, Sahara is the second area involved in the atmospheric Cs-137 persistence due to dust transport events. The whole of these events has a mean contribution of around 1/3 of the Cs-137 background level at the French scale. The last identified process is the wood burning during winter. Even if its emission factor is low, spatial extent of source areas and quantities used at the season scale makes wood burning a significant process compared to ambient trace levels. At the French scale, around 1011 Bq of Cs-137 are yearly resuspended by this process. During this season, the decrease of ventilation conditions in the lower atmosphere leads to an increase of the background level whereas significant increases are due to long range transport events from Eastern Europe

  19. Comparison of concentrations of natural and artificial radionuclides in Plankton from French Polynesian and Australian coastal waters

    International Nuclear Information System (INIS)

    Poletiko, C.; Twining, J.R.; Jeffree, R.A.

    1994-01-01

    Zooplankton samples from French Polynesian and Australian coastal waters were analysed for natural and artificial radionuclides. Quality control was assured by correlating replicate analyses between three laboratories and by participation in an international intercomparison exercise. Pu239/240 was detected sporadically among samples from both regions, with the highest levels being more consistently found in Tuamotu-Gambier samples. The artificial radionuclides Cs-137, Cs-134, Sr-90 and Co-60 were not detected. Of the natural nuclides, Ac-228 was detected in shallow continental waters off Northern Australia and an inverse relationship (P<0.02) was established between plankton density and their Po-210 concentration. (authors). 2 figs., 2 tabs., 9 refs

  20. Artificial radionuclide tracer supply to the Denmark Strait overflow between 1972 and 1981

    Science.gov (United States)

    Livingston, Hugh D.; Swift, James H.; Ostlund, H. Gote

    1985-01-01

    Measurements of the concentrations of the artificial radionuclides 3H, 137Cs, and 90Sr in the northern Irminger Sea in 1972 and 1981 are reported. In both years, tracer measurements from this area included data from samples of the dense overflow water from the north through Denmark Strait. All three tracers were strongly correlated inversely with salinity in the dense outflows—the tracer maxima being related directly to the salinity minimum. When the tracer characteristics in the outflows in 1972 and 1981 were compared, concentrations of all in 1981 were observed to be about double the 1972 values. The individual tracer concentrations—on a decay-corrected, density-normalized basis—were higher in increasing order: 90Sr (+93%) seas of advected European nuclear fuel reprocessing wastes. Both the tracer and hydrographic data are used to identify northern locations of intermediate water formation capable of supplying the observed dense overflow water characteristics. It is argued, from the time taken for the overflow water to reflect the new surface 137Cs source, that transport from the source to the overflow can be quite rapid (about 2 years).

  1. Measurement of artificial radionuclides in whole diets around the BNF plc reprocessing plant at Sellafield, Cumbria

    International Nuclear Information System (INIS)

    Mondon, K.J.; Walters, B.

    1993-01-01

    The Ministry of Agriculture, Fisheries and Food has conducted a duplicate diet study around the BNF reprocessing plant of Sellafield in Cumbria. Samples were collected from adults and children. The results of analyses for a number of artificial radionuclides are reported; dose calculations using actual food intakes have also been made. Samples were obtained in both winter (phase 1) and summer (phase 11), between which times the Chernobyl accident occurred, making site-specific dose assessment from caesium isotopes difficult in summer samples. Control diets were collected from a coastal area in Lancashire. Average annual doses based on pre-Chernobyl sampling ranged from 2 μSv in control children to 14 μSv in study adults. This range increased to 9-50 μSv in the second phase of the study. Maximum individual doses were 86 μSv in phase 1 and 102 μ in phase 11, these being well within the government's target dose for members of the public. (author)

  2. Artificial radionuclide tracer supply to the Denmark strait overflow between 1972 and 1981

    International Nuclear Information System (INIS)

    Livingston, H.D.; Swift, J.H.; Ostlund, H.G.

    1985-01-01

    Measurements of the concentrations of the artificial radionuclides 3 H, 137 Cs, and 90 Sr in the northern Irminger Sea in 1972 and 1981 are reported. In both years, tracer measurements from this area included data from samples of the dense overflow water from the north through Denmark Strait. All three tracers were strongly correlated inversely with salinity in the dense outflows-the tracer maxima being related directly to the salinity minimum. When the tracer characteristics in the outflows in 1972 and 1981 were compared, concentrations of all in 1981 were observed to be about double the 1972 values. The individual tracer concentrations-on a decay-corrected, density-normalized basis-were higher in increasing order: 90 Sr(+93%) 3 H(+115%) 137 Cs(+150%). The relatively greater increases for 3 H and 137 Cs were attributed to contributions of new sources of these tracers in northern surface waters: the 3 H source is argued to derive from atmospheric hydrological recycling, whereas the 137 Cs source is identified as the input to the Greenland and Iceland seas of advected European nuclear fuel reprocessing wastes. Both the tracer and hydrographic data are used to identify northern locations of intermediate water formation capable of supplying the observed dense overflow water characteristics. It is argued, from the time taken for the overflow water to reflect the new surface 137 Cs source, that transport from the source to the overflow can be quite rapid (about 2 years)

  3. Behavior of radionuclides in nuclear gas stimulation applications

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jr, C F [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    The Gasbuggy experiment has presented a unique opportunity to investigate the behavior of radionuclides over an extended period of time in a somewhat unusual environment. In addition to the obvious practical utility of this investigation for Plowshare applications, the information gained has value of a purely scientific nature. Both aspects of the Gas Quality program for Gasbuggy are discussed in this presentation. The study of Gasbuggy results is divided into two distinct periods, according to the field operations. During the initial six months following detonation, the chimney reentry well was shut-in, and the nuclear chimney served as a chemical and radiochemical reaction vessel. A detailed examination of the concentrations and specific activities of tritium and C{sup 14} is presented as a function of the changing chemical composition of the chimney gas and as a function of time. The effects of radiochemical exchange reactions, together with the tritium isotope effect, are demonstrated. Following this shut-in period, a series of production and flushing tests was conducted. During these experiments, the chimney gas composition was seen to change about as would be expected due to dilution of the chimney gas with formation gas. An examination of radionuclide concentrations and specific activities during the production tests demonstrated the relative unimportance of isotopic exchange and chemical reactions during this period, as compared to the early shut-in periods. Within the limitations of the Gasbuggy experience a generalized model of the behavior of tritium and C{sup 14} can be deduced. The discussion involves estimation of initial distribution of activities, the effects of chemical reactions and isotopic exchange on this distribution, and the importance of the environment in determining the level of radioactivity contamination to be expected. (author)

  4. Behavior of natural radionuclides in wastewater treatment plants

    International Nuclear Information System (INIS)

    Camacho, A.; Montaña, M.; Vallés, I.; Devesa, R.; Céspedes-Sánchez, R.; Serrano, I.; Blázquez, S.; Barjola, V.

    2012-01-01

    56 samples, including influent, primary effluent, secondary effluent and final effluent wastewater from two Spanish municipal wastewater treatment plants (WWTPs), were analyzed to assess both the occurrence and behavior of natural radioactivity during 12 sampling campaigns carried out over the period 2007–2010. Influent and final effluent wastewaters were sampled by taking into account the hydraulic residence time within the WWTP. A wide range of gross alpha activities (15–129 mBq/L) and gross beta activities (477–983 mBq/L) in liquid samples were obtained. A correlation analysis between radioactivity in liquid samples and the performance characteristics of the WWTPs was performed. The results in liquid samples showed that gross beta activities were not influenced by treatment in the studied WWTPs. However, gross alpha activities behave differently and an increase was detected in the effluent values compared with influent wastewater. This behavior was due to the increase in the total dissolved uranium produced during secondary treatment. The results indicate that the radiological characteristics of the effluents do not present a significant radiological risk and make them suitable for future applications. - Highlights: ► Liquids from WWTPs were analyzed to know the behavior of natural radionuclides. ► Gross beta activities were not influenced by treatment in the studied WWTPs. ► Increase in gross alpha activity was observed due to uranium desorption/solubilisation. ► Correlation between gross alpha activity and the chemical oxygen demand was found

  5. On the behaviour of artificial radionuclides at the Baltic sea coastal zone

    International Nuclear Information System (INIS)

    Styro, D.B.; Astrauskene, N.P.; Kadzhene, G.I.; Lukinskene, M.V.

    1988-01-01

    The measured results of the 137 Cs, 90 Sr and 144 Ce radionuclide concentrations near the settlement of Juodkrante at the Baltic Sea coast have been considered. The instability of the mean values of the radionuclide concentrations, especially that of strontium-90, has been determined. A certain increase of the radionuclide concentration near the sea coast as compared to that in the open sea has been noted, as well as the influence of the stormy weather on the absolute values of the radionuclide concentration at the coastal zone. 5 refs.; 3 figs.; 1 tab

  6. Development of dynamic compartment models for prediction of radionuclide behaviors in rice paddy fields

    International Nuclear Information System (INIS)

    Takahashi, Tomoyuki; Tomita, Ken'ichi; Yamamoto, Kazuhide; Uchida, Shigeo

    2007-01-01

    We are developing dynamic compartment models for prediction of behaviors of some important radionuclides in rice paddy fields for safety assessment of nuclear facilities. For a verification of these models, we report calculations for several different deposition patterns of radionuclides. (author)

  7. Rapid determination of radon daughters and of artificial radionuclides in air by online gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Hoetzl, H.; Winkler, R.

    1993-01-01

    For the determination of airborne radionuclide concentrations in real time, a fixed filter device was constructed which fits directly onto a germanium detector with standard nuclear electronics and a multichannel analyzer buffer connected via a data line to a personal computer for remote control and on-line spectrum evaluation. The on-line gamma-ray spectrometer was applied to the study of radon decay product concentrations in ground-level air and to the rapid detection of only contamination of the environmental air by artificial radionuclides. At Munich-Neuherberg, depending on the meteorological conditions, the measured air concentrations of 214 Pb, the first gamma-ray-emitting member of the 222 Rn decay series, varied from about 1 to 50 Bq m -3 . For the artifical radionuclides 60 Co, 131 I and 137 Cs the detection limits were determined as a function of the varying natural radon daughter concentrations at sampling and counting times of 1 h or 1 day. For these radionuclides minimum detectable air activity concentrations of 0.3 or 0.001 Bq m -3 , respectively, were obtained at low radon daughter levels. At high radon daughter levels the respective detection limits were found to be higher by a factor of only about 2. (orig.)

  8. Rapid determination of radon daughters and of artificial radionuclides in air by online gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hoetzl, H.; Winkler, R. (GSF-Forschungszentrum fuer Umwelt und Gesundheit, Neuherberg (Germany). Inst. fuer Strahlenschutz)

    1993-04-01

    For the determination of airborne radionuclide concentrations in real time, a fixed filter device was constructed which fits directly onto a germanium detector with standard nuclear electronics and a multichannel analyzer buffer connected via a data line to a personal computer for remote control and on-line spectrum evaluation. The on-line gamma-ray spectrometer was applied to the study of radon decay product concentrations in ground-level air and to the rapid detection of only contamination of the environmental air by artificial radionuclides. At Munich-Neuherberg, depending on the meteorological conditions, the measured air concentrations of [sup 214]Pb, the first gamma-ray-emitting member of the [sup 222]Rn decay series, varied from about 1 to 50 Bq m[sup -3]. For the artifical radionuclides [sup 60]Co, [sup 131]I and [sup 137]Cs the detection limits were determined as a function of the varying natural radon daughter concentrations at sampling and counting times of 1 h or 1 day. For these radionuclides minimum detectable air activity concentrations of 0.3 or 0.001 Bq m[sup -3], respectively, were obtained at low radon daughter levels. At high radon daughter levels the respective detection limits were found to be higher by a factor of only about 2. (orig.).

  9. Behavior of colloids in radionuclide migration in deep geologic formation

    International Nuclear Information System (INIS)

    Kanno, Takuji

    1994-01-01

    In case high level waste is isolated in deep strata, it is important to elucidate the behavior of movement that radionuclides take in the strata. Recently, it has been recognized that the participation of colloids is very important, and it has been studied actively. In this study, as to the mechanism of the adsorption of colloids to geological media or buffers, analysis was carried out for a number of systems, and it was clarified in what case they are caught or they move without being caught. Also it is considered what research is necessary hereafter. First, the kinds of colloids are shown. As the properties of colloids that control the movement of colloids in groundwater in deep strata, the surface potential, shape, size and so on of colloids are conceivable. These properties are briefly discussed. As the interaction of colloids and geological media, the interaction by electrostatic attraction, the fast and slow movement of colloids through rock crevices, and the filtration of colloids in buffers and porous media are described. The experimental results on the movement of colloids are reported. (K.I.)

  10. Physico-chemical behavior of radionuclides in seawater

    International Nuclear Information System (INIS)

    Kimura, Yuichiro; Ogawa, Yoshihiro; Honda, Yoshihide; Katsurayama, Kosuke.

    1980-01-01

    To elucidate the physico-chemical states of radionuclides in seawater in relation to uptake by the marine biosphere, the physicochemical behavior of radiocobalt, radioruthenium and radiocerium in seawater was investigated by electrodialysis, high-voltage paper electrophoresis, and also by paper chromatography for nitrosylruthenium complexes. Most of the radiocobalt in seawater behaved as dialytic cations. However, these cationic species were not necessarily simple divalent, because their electrophoretic bands were rather diffuse and showed two peaks temporarily. The electroneutral form also increased with aging in seawater. The radioruthenium in seawater showed relatively a number of well-defined species which could be readily classified into anionic, cationic, electroneutral, colloidal or particulate, non-dialytic and more or less adsorbable species. The radioruthenium in the chloro and nitratonitrosylruthenium complexes occurred mainly electroneutral and anionic species, while nitro and binuclear oxygen-bridged nitratonitrosylruthenium complexes showed dominant anionic species. The hydrolysis of higher nitro and nitratonitrosylruthenium complexes to lower ones was demonstrated with aging in seawater by paper chromatography. The radiocerium in seawater showed initially cationic species. However, the electroneutral and anionic species were revealed with aging by electrodialysis. The radiocerium were strongly adsorbed on filter paper at the starting band in paper electrophoresis, presumably because of the formation of strongly adsorbable or insoluble hydrolytic species or particle formation. (author)

  11. Behavior of radionuclides in the ecosystem; Comportamento dos radionuclideos no ecossistema

    Energy Technology Data Exchange (ETDEWEB)

    Mazzilli, Barbara Paci

    2016-07-01

    In this chapter 4 the Naturally Occurring Radioactive Material - NORM is presented, besides an introduction to the environmental radiological impact of NORM industries, the waste transportation, its proprieties and the behavior of specific groups of radionuclides in the ecosystems.

  12. Distribution of artificial radionuclides in particle-size fractions of soil on fallout plumes of nuclear explosions.

    Science.gov (United States)

    Kabdyrakova, A M; Lukashenko, S N; Mendubaev, A T; Kunduzbayeva, A Ye; Panitskiy, A V; Larionova, N V

    2018-06-01

    In this paper are analyzed the artificial radionuclide distributions ( 137 Cs, 90 Sr, 241 Am, 239+240 Pu) in particle-size fractions of soils from two radioactive fallout plumes at the Semipalatinsk Test Site. These plumes were generated by a low-yield surface nuclear test and a surface non-nuclear experiment with insignificant nuclear energy release, respectively, and their lengths are approximately 3 and 0,65 km. In contrast with the great majority of similar studies performed in areas affected mainly by global fallout where adsorbing radionuclides such as Pu are mainly associated with the finest soil fractions, in this study it was observed that along both analyzed plumes the highest activity concentrations are concentrated in the coarse soil fractions. At the plume generated by the surface nuclear test, the radionuclides are concentrated mainly in the 1000-500 μm soil fraction (enrichment factor values ranging from 1.2 to 3.8), while at the plume corresponding to the surface non-nuclear test is the 500-250 μm soil fraction the enriched one by technogenic radionuclides (enrichment factor values ranging from 1.1 to 5.1). In addition, the activity concentration distributions among the different soil size fractions are similar for all radionuclides in both plumes. All the obtained data are in agreement with the hypothesis indicating that enrichment observed in the coarse fractions is caused by the presence of radioactive particles resulted from the indicated nuclear tests. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Measurement of natural and artificial radionuclide concentrations in meat consumed in Hong Kong

    International Nuclear Information System (INIS)

    Mao, S.Y.; Yu, K.N.

    1995-01-01

    Radionuclides in meat are determined using the EG and G ORTEC photon spectrometer system. Most of the naturally occurring radionuclides are found to have specific activities below the detectable limit. For our samples, 40 K is found to have values ranging from 295-407 Bq/kg, 172-423 Bq/kg and 172-282 Bq/kg for beef, pork and chicken meat samples, respectively, while 137 Cs has values from 0.19-2 Bq/kg, 0.34-0.71 Bq/kg and 0.12-0.53 Bq/kg, respectively. The estimated weighted committed dose equivalent due to the ingestion of natural radionuclides and 137 Cs in meat is 137 Cs in both sexes are less than the level recommended by the International Commission on Radiological Protection. (author)

  14. First artificial radionuclides for Czechoslovakia after World War II. Pt 2

    International Nuclear Information System (INIS)

    Tesinska, Emilie

    2014-01-01

    The paper outlines negotiations on supplies of radionuclides for scientific research and applications in medicine from abroad (the USA, Canada, Great Britain, Sweden, France and the USSR) held by Czechoslovak scientists and public administration (the Ministry of Public Health, Foreign Affairs and Foreign Trade) in 1947 - 1951. Special attention is paid to the complicated and vain debates in the Czechoslovak government (presided by the communist Klement Gottwald) on the offer of radionuclides from the USA for foreign applicants (as declared by US president Truman in September 1947). (orig.)

  15. Sediments as indicators of artificial radionuclide distribution west of La Hague

    International Nuclear Information System (INIS)

    Guegueniat, P.; Auffret, J.P.; Ballada, J.

    1981-01-01

    Four-year investigations of the coastal surface sediments and associated radionuclides in the English Channel show complex distribution patterns around La Hague. Plutonium ratios in the particulate fraction confirm the general understanding gathered from long-term gamma studies - mainly that accumulation of La Hague generated radionuclides is in the Bay of Mont-Saint-Michel and along the Normandy-Brittany Coast. The oil from the Amoco Cadiz accident caused a significant increase in coastal sediment activity of 144 Ce. Experimental studies with plutonium and hydrocarbons indicate that plutonium is more difficult to desorb than 144 Ce. (author)

  16. Disruption of behavior and brain metabolism in artificially reared rats.

    Science.gov (United States)

    Aguirre-Benítez, Elsa L; Porras, Mercedes G; Parra, Leticia; González-Ríos, Jacquelina; Garduño-Torres, Dafne F; Albores-García, Damaris; Avendaño, Arturo; Ávila-Rodríguez, Miguel A; Melo, Angel I; Jiménez-Estrada, Ismael; Mendoza-Garrido, Ma Eugenia; Toriz, César; Diaz, Daniel; Ibarra-Coronado, Elizabeth; Mendoza-Ángeles, Karina; Hernández-Falcón, Jesús

    2017-12-01

    Early adverse life stress has been associated to behavioral disorders that can manifest as inappropriate or aggressive responses to social challenges. In this study, we analyzed the effects of artificial rearing on the open field and burial behavioral tests and on GFAP, c-Fos immunoreactivity, and glucose metabolism measured in anxiety-related brain areas. Artificial rearing of male rats was performed by supplying artificial milk through a cheek cannula and tactile stimulation, mimicking the mother's licking to rat pups from the fourth postnatal day until weaning. Tactile stimulation was applied twice a day, at morning and at night, by means of a camel brush on the rat anogenital area. As compared to mother reared rats, greater aggressiveness, and boldness, stereotyped behavior (burial conduct) was observed in artificially reared rats which occurred in parallel to a reduction of GFAP immunoreactivity in somatosensory cortex, c-Fos immunoreactivity at the amygdala and primary somatosensory cortex, and lower metabolism in amygdala (as measured by 2-deoxi-2-[ 18 fluoro]-d-glucose uptake, assessed by microPET imaging). These results could suggest that tactile and/or chemical stimuli from the mother and littermates carry relevant information for the proper development of the central nervous system, particularly in brain areas involved with emotions and social relationships of the rat. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1413-1429, 2017. © 2017 Wiley Periodicals, Inc.

  17. Remobilisation of artificial radionuclides from the sediment of the Irish Sea

    International Nuclear Information System (INIS)

    Hunt, G.J.; Kershaw, P.J.

    1990-01-01

    The past decade has seen significant decreases in discharges of radioactivity in liquid wastes from the British Nuclear Fuels plc (BNFL) plant at Sellafield. Concentrations of many Sellafield-derived radionuclides in the water of the Irish Sea have decreased as a result. This will result in the return of previously contaminated sediment to the sediment surface and enhanced seawater/pore-water mixing by bio-irrigation, and may be responsible for higher rates of particle exchange across the sediment-seawater interface. In these circumstances, the decrease in seawater concentrations might be expected to be accompanied by the remobilisation of sediment-bound radionuclides into the water column. We have tested this hypothesis in the Sellafield situation in two ways. First, the differences were examined between measured concentrations of radionuclides in sea water and the concentrations which are to be expected on the basis of extrapolation from the conditions of steadier discharge rates experienced in the past. Secondly, modelling studies have shown that migration of radionuclides into the water phase is likely under these conditions. (author)

  18. Artificial intelligence: Collective behaviors of synthetic micromachines

    Science.gov (United States)

    Duan, Wentao

    Synthetic nano- and micromotors function through the conversion of chemical free energy or forms of energy into mechanical motion. Ever since the first reports, such motors have been the subject of growing interest. In addition to motility in response to gradients, these motors interact with each other, resulting in emergent collective behavior like schooling, exclusion, and predator-prey. However, most of these systems only exhibit a single type of collective behavior in response to a certain stimuli. The research projects in the disseratation aim at designing synthetic micromotors that can exhibit transition between various collective behaviors in response to different stimuli, as well as quantitative understanding on the pairwise interaction and propulsion mechanism of such motors. Chapter 1 offers an overview on development of synthetic micromachines. Interactions and collective behaviors of micromotors are also summarized and included. Chapter 2 presents a silver orthophosphate microparticle system that exhibits collective behaviors. Transition between two collective patterns, clustering and dispersion, can be triggered by shift in chemical equilibrium upon the addition or removal of ammonia, in response to UV light, or under two orthogonal stimuli (UV and acoustic field) and powering mechanisms. The transitions can be explained by the self-diffusiophoresis mechanism resulting from either ionic or neutral solute gradients. Potential applications of the reported system in logic gates, microscale pumping, and hierarchical assembly have been demonstrated. Chapter 3 introduces a self-powered oscillatory micromotor system in which active colloids form clusters whose size changes periodically. The system consists of an aqueous suspension of silver orthophosphate particles under UV radiation, in the presence of a mixture of glucose and hydrogen peroxide. The colloid particles first attract with each other to form clusters. After a lag time of around 5min, chemical

  19. Artificial environmental radionuclides in Europe and methods of lowering their foodstuff contamination – a review

    Directory of Open Access Journals (Sweden)

    Katarína Beňová

    2016-01-01

    Full Text Available This review discusses the consequences of the food chain contamination with radionuclides, especially focusing on the radiocaesium impact after the Chernobyl nuclear accident. In particular, the 137Cs isotope still represents a risk. Until present it is still detectable in the meat of game animals, especially in wild boar, but also in elk and reindeer. Although the occurrence of highly contaminated foods in most of Europe is currently limited, along the German-Czech border (the Šumava Region the activity concentration of the 137Cs isotope in the meat of wild boar exceeds the acceptable limit several times. Additionally, the article describes simple processing technologies (cooking, pickling etc. that lead to reduction of radionuclides in contaminated food.

  20. Determination of artificial and natural radionuclides and others trace elements in environmental samples form Antarctica

    International Nuclear Information System (INIS)

    Schuch, L.A.; Godoy, J.M.; Nordemann, D.J.R.

    1994-01-01

    The results of the radioactive elements concentrations, determined by gamma spectrometry and the others trace elements determined by neutron activation analysis of several environmental samples (soils, marine sediments, algae mosses and lichens) in Comandante Ferraz Antartica Station are presented. The high concentrations of Cs-137 were found in lichens and mosses samples and the soils and sediments showed concentrations of natural radionuclides. (C.G.C.). 8 refs, 1 fig, 3 tabs

  1. The oceanic geochemistry of artificial radionuclides: The ''SEEP'' project: [Final] progress report for period 1 August 1986-31 July 1987

    International Nuclear Information System (INIS)

    Sholkovitz, E.R.; Livingston, H.D.

    1986-03-01

    The objective of the SEEP project was to quantify the biological and geochemical processes controlling the concentration, distribution, flux, and speciation of natural and artificial radionuclides. The focus is on the shelf/slope region. Research was concentrated on the sediment chemistry of plutonium and on the nature of fallout transuranic transport in, and removal from, waters of the US continental margin

  2. ALMERA Proficiency Test: Determination of Natural and Artificial Radionuclides in Soil and Water. IAEA-TEL-2011-04

    International Nuclear Information System (INIS)

    2013-01-01

    The Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA) network is a cooperative effort of analytical laboratories worldwide. Members of the network are nominated by their respective Member States on the expectation of providing reliable and timely analysis of environmental samples in the event of an accidental or intentional release of radioactivity. The ALMERA network consists of 131 laboratories representing 81 Member States at December 2012. The IAEA's Environment Laboratories in Seibersdorf and Monaco are the central coordinators of the ALMERA network activities. The IAEA helps the ALMERA network to maintain their readiness by coordinating activities, including the organization of meetings, development of standardized methods of sample collection and analysis, and organization of interlaboratory comparison exercises and proficiency tests as tools for external quality control. IAEA proficiency tests and interlaboratory comparison exercises are organized on a regular basis specifically for the members of the ALMERA network. At least one exercise is organized per year by the IAEA for the ALMERA network. These exercises are designed to monitor and to demonstrate the performance and analytical capabilities of the network members, and to identify gaps and problem areas where further development is needed. The ALMERA proficiency tests enable ALMERA members to report their results on gamma emitting radionuclides in a very short time frame, i.e. three days, which is what would be required for emergency response. This publication presents the results of the ALMERA proficiency test IAEA-TEL-2011-04 on the determination of natural and artificial radionuclides in water and soil. The methodologies, data evaluation approach, summary evaluation of each radionuclide and individual evaluation reports for each laboratory are also described

  3. Determination of distribution coefficient (Kd's) of some artificial and naturally occurring radionuclide in fresh and marine coastal water sediment

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Mamish, S; Haleem, M. A.

    2004-12-01

    Distribution coefficients of artificial and natural radionuclides in fresh and marine water sediment are used in modeling radionuclide dispersion in water system, and the radiation risk and environmental investigating of impact of radioactive emissions, due to routine operations of nuclear plants or disposal and burial of radioactive waste in the environment. In the present work, distribution coefficient of uranium, lead, polonium, radium (naturally occurring radionuclides that may be emitted into the Syrian environment by the phosphate and oil industry with relatively high concentrations) and caesium 137 and strontium 85, in fresh water sediment (Euphrates River, Orantos River and Mzzerib Lake) and marine coastal water (Lattakia, Tartous and Banias). Distribution coefficients were found to vary between (5.8-17.18)*10 3 , (2.2-8.11)*10 3 , (0.22-2.08)*10 3 , (0.16-0.19)*10 3 , (0.38-0.69)*10 3 and 49-312 for polonium, lead, uranium, radium, cesium and strontium respectively. Results have indicated that most measurement distribution coefficients in the present study were lower than those values reported in IAEA documents for marine coastal sediment. In addition, variations of Kd's with aqueous phase composition and sediment elemental and mineralogical composition and its total organic materials content have been studied, where liner correlation coefficients for each isotope with different parameters have been determined. The obtained data reported in this study can be used for radioactive contaminants dispersion and transfer in Syrian river, lake and coast to assess risks to public due to discharges of the phosphate and oil industry into the Syrian environment. (Authors)

  4. Natural and artificial radionuclides in selected Styrian soils and plants before and after the reactor accident in Chernobyl

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, G; Gries, A [Graz Univ. (Austria); Mueller, H J; Oswald, K [Technische Univ., Graz (Austria). Inst. fuer Theoretische Physik und Reaktorphysik

    1989-01-01

    This paper reports on natural radioactivity due to the uptake of {sup 40}K and the radionuclides of the {sup 238}U and {sup 232}Th series. Selected examples show the concentrations of radionuclides in soils, lower and higher plants before and after the Chernobyl accident. The changes in the amount of radioactivity which have occurred during the vegetation periods of 1987 and 1988 have been investigated. It is also demonstrated how the conditions have changed in the following two periods of growth. In leaves of deciduous trees which were directly contaminated in 1986 natural radioactivity is sometimes higher than artificial one today. This has not been observed in conifers, because the needles contaminated in 1986 have not yet been shed. The {sup 137}Cs activity in mosses and lichens has hardly decreased. It is therefore possible to produce autoradiographs at the Styrian test site locations. Within the same genus of fungi, Cs-discriminating and Cs-accumulating species have been noted. In the latter, radioactivity has probably increased since 1986. (author).

  5. Determination of natural and artificial radionuclides and some trace metals in manufactured food of Syrian infant and their intake rates

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Nashawati, A.; Amin, Y.; Ibrahim, S.

    2001-06-01

    Natural and artificial radionuclides and some trace metals in some manufactured food of Syrian infant and their intake rates have been determined. Seventeen manufactured food and eleven types of canned milked, were collected from the local market, and chemically and radioactivity analyzed; radium-226, radium-228, potassium-40, lead-210, polonium-210 and trace metals (Pb, Cd, Cu, Zn) being determined. Results have shown that 210 Po concentration varied between 0.38 and 2.89 Bq/Kg in canned milk while the highest concentration in infant food was found to be 1.69 Bq/Kg; other radionuclides concentration being below the limit of detection. Total uranium concentration varied between 2.2 and 10.5 μg/Kg in milk samples and 0.78-6.0 μg/Kg in food stuff samples. In addition, concentration of Pb and Cd in all samples were found to be very low and lower than the lower of limit of detection of the analytical method. (author)

  6. Rapid determination of long-lived artificial alpha radionuclides using time interval analysis

    International Nuclear Information System (INIS)

    Uezu, Yasuhiro; Koarashi, Jun; Sanada, Yukihisa; Hashimoto, Tetsuo

    2003-01-01

    It is important to monitor long lived alpha radionuclides as plutonium ( 238 Pu, 239+240 Pu) in the field of working area and environment of nuclear fuel cycle facilities, because it is well known that potential risks of cancer-causing from alpha radiation is higher than gamma radiations. Thus, these monitoring are required high sensitivity, high resolution and rapid determination in order to measure a very low-level concentration of plutonium isotopes. In such high sensitive monitoring, natural radionuclides, including radon ( 222 Rn or 220 Rn) and their progenies, should be eliminated as low as possible. In this situation, a sophisticated discrimination method between Pu and progenies of 222 Rn or 220 Rn using time interval analysis (TIA), which was able to subtract short-lived radionuclides using the time interval distributions calculation of successive alpha and beta decay events within millisecond or microsecond orders, was designed and developed. In this system, alpha rays from 214 Po, 216 Po and 212 Po are extractable. TIA measuring system composes of Silicon Surface Barrier Detector (SSD), an amplifier, an Analog to Digital Converter (ADC), a Multi-Channel Analyzer (MCA), a high-resolution timer (TIMER), a multi-parameter collector and a personal computer. In ADC, incidental alpha and beta pulses are sent to the MCA and the TIMER simultaneously. Pulses from them are synthesized by the multi-parameter collector. After measurement, natural radionuclides are subtracted. Airborne particles were collected on membrane filter for 60 minutes at 100 L/min. Small Pu particles were added on the surface of it. Alpha and beta rays were measured and natural radionuclides were subtracted within 5 times of 145 msec. by TIA. As a result of it, the hidden Pu in natural background could be recognized clearly. The lower limit of determination of 239 Pu is calculated as 6x10 -9 Bq/cm 3 . This level is satisfied with the derived air concentration (DAC) of 239 Pu (8x10 -9 Bq/cm 3

  7. Studies of radionuclides behavior on heavily contaminated 5-km zone of СhNPP

    Directory of Open Access Journals (Sweden)

    D. M. Bondarkov

    2016-12-01

    Full Text Available Studies of the radionuclides behavior in the soils of “Red Forest” landfill in the nearest 5-km ChNPP zone were carried out during 2014 - 2015. The parameters of vertical migration and halftimes of upper 5-cm soil layer decontamination were obtained. Forms of occurrence of 90Sr and 137Cs, as well as the disperse composition of the Chernobyl origin fuel particles were evaluated. Behavior of radionuclides described in conditions of the convection-diffusion model and the parameters of the model slightly changed over the past decade.

  8. The enrichment behavior of natural radionuclides in pulverized oil shale-fired power plants

    International Nuclear Information System (INIS)

    Vaasma, Taavi; Kiisk, Madis; Meriste, Tõnis; Tkaczyk, Alan Henry

    2014-01-01

    The oil shale industry is the largest producer of NORM (Naturally Occurring Radioactive Material) waste in Estonia. Approximately 11–12 million tons of oil shale containing various amounts of natural radionuclides is burned annually in the Narva oil shale-fired power plants, which accounts for approximately 90% of Estonian electricity production. The radionuclide behavior characteristics change during the fuel combustion process, which redistributes the radionuclides between different ash fractions. Out of 24 operational boilers in the power plants, four use circulating fluidized bed (CFB) technology and twenty use pulverized fuel (PF) technology. Over the past decade, the PF boilers have been renovated, with the main objective to increase the efficiency of the filter systems. Between 2009 and 2012, electrostatic precipitators (ESP) in four PF energy blocks were replaced with novel integrated desulphurization technology (NID) for the efficient removal of fly ash and SO 2 from flue gases. Using gamma spectrometry, activity concentrations and enrichment factors for the 238 U ( 238 U, 226 Ra, 210 Pb) and 232 Th ( 232 Th, 228 Ra) family radionuclides as well as 40 K were measured and analyzed in different PF boiler ash fractions. The radionuclide activity concentrations in the ash samples increased from the furnace toward the back end of the flue gas duct. The highest values in different PF boiler ash fractions were in the last field of the ESP and in the NID ash, where radionuclide enrichment factors were up to 4.2 and 3.3, respectively. The acquired and analyzed data on radionuclide activity concentrations in different PF boiler ashes (operating with an ESP and a NID system) compared to CFB boiler ashes provides an indication that changes in the fuel (oil shale) composition and boiler working parameters, as well as technological enhancements in Estonian oil shale fired power plants, have had a combined effect on the distribution patterns of natural radionuclides in

  9. Artificial radionuclides in oils from the underground nuclear test site (Perm region, Russia)

    International Nuclear Information System (INIS)

    Kalmykov, S.N.; Sapozhnikov, Yu.A.; Goloubov, B.N.

    1998-01-01

    Underground nuclear tests (UNT) are one of the possible sources of radioactive contamination of environment. About 2500 UNTs were carried out both for military and industrial (peaceful) purposes. In the former Soviet Union most of peaceful UNTs were oriented to the needs of the gas- and oil-extracting industry. Earlier it was considered that the holes of UNT are hermetic and the leakage of radionuclides is negligible. In this work nine oil samples from Gezh oil deposit in Perm region of Russia collected from different holes both where the explosion took part and from distant holes were analyzed for 3 H and 14 C and such fission products as 90 Sr and 134,137 Cs. For the determination of gamma-emitting radionuclides the gamma spectrometry with HPGe detector was used. For 90 Sr determination the measurements of Cherenkov radiation generated by daughter 90 Y were carried out with liquid scintillation equipment. It showed that even in the oil samples from the hole where the explosion took place no measurable 134,137 Cs and 90 Sr activities were detected. For 3 H and 14 C determination the oil samples were fractionated by distillation. For each sample 10-12 fractions were taken. Liquid scintillation spectrometry was used for 3 H and 14 C simultaneous determination. It was shown that in all samples the 3 H and 14 C concentrations are higher than the background level and for the hole where the explosion took place reached the value of about 1.3 x 10 5 Bq/L for low boiling fraction (40-750C). The 3 H and 14 C enrichment of oils from distant holes shows that UNT cavities are not hermetic and the radionuclide migration is not negligible. (author)

  10. Determination of the radioactivity of the artificial 137Cs radionuclide in the Tatra Mountains

    International Nuclear Information System (INIS)

    Kubica, B.; Skiba, S.; Golas, J.; Stobinski, M.; Drewnik, M.; Tuteja-Krysa, M.; Misiak, R.

    2006-01-01

    Sixty samples were collected in different regions of the Tatra Mountains (Poland). It has been found that 137 Cs and 40 K content in the samples strongly depends on the content of the organic matter in the soil and height of the region of the sample collection. Potassium content in the the blueberries and in the moss strongly influences the bioaccumulation of the 137 Cs radionuclide by these plants. Map of the 137 Cs concentration in the polish part of the Tatra Mountains is presented

  11. Geochemical effects on the behavior of LLW radionuclides in soil/groundwater environments

    Energy Technology Data Exchange (ETDEWEB)

    Krupka, K.M.; Sterne, R.J. [Pacific Northwest Lab., Richland, WA (United States)

    1995-12-31

    Assessing the migration potential of radionuclides leached from low-level radioactive waste (LLW) and decommissioning sites necessitates information on the effects of sorption and precipitation on the concentrations of dissolved radionuclides. Such an assessment requires that the geochemical processes of aqueous speciation, complexation, oxidation/reduction, and ion exchange be taken into account. The Pacific Northwest National Laboratory (PNNL) is providing technical support to the U.S. Nuclear Regulatory Commission (NRC) for defining the solubility and sorption behavior of radionuclides in soil/ground-water environments associated with engineered cementitious LLW disposal systems and decommissioning sites. Geochemical modeling is being used to predict solubility limits for radionuclides under geochemical conditions associated with these environments. The solubility limits are being used as maximum concentration limits in performance assessment calculations describing the release of contaminants from waste sources. Available data were compiled regarding the sorption potential of radionuclides onto {open_quotes}fresh{close_quotes} cement/concrete where the expected pH of the cement pore waters will equal to or exceed 10. Based on information gleaned from the literature, a list of preferred minimum distribution coefficients (Kd`s) was developed for these radionuclides. The K{sub d} values are specific to the chemical environments associated with the evolution of the compositions of cement/concrete pore waters.

  12. Radionuclide behavior in water saturated porous media: Diffusion and infiltration coupling of thermodynamically and kinetically controlled radionuclide water - mineral interactions

    International Nuclear Information System (INIS)

    Spasennykh, M.Yu.; Apps, J.A.

    1995-05-01

    A model is developed describing one dimensional radionuclide transport in porous media coupled with locally reversible radionuclide water-mineral exchange reactions and radioactive decay. Problems are considered in which radionuclide transport by diffusion and infiltration processes occur in cases where radionuclide water-solid interaction are kinetically and thermodynamically controlled. The limits of Sr-90 and Cs-137 migration are calculated over a wide range of the problem variables (infiltration velocity, distribution coefficients, and rate constants of water-mineral radionuclide exchange reactions)

  13. Radionuclide toxicity

    International Nuclear Information System (INIS)

    Galle, P.

    1982-01-01

    The aim of this symposium was to review the radionuclide toxicity problems. Five topics were discussed: (1) natural and artificial radionuclides (origin, presence or emission in the environment, human irradiation); (2) environmental behaviour of radionuclides and transfer to man; (3) metabolism and toxicity of radionuclides (radioiodine, strontium, rare gas released from nuclear power plants, ruthenium-activation metals, rare earths, tritium, carbon 14, plutonium, americium, curium and einsteinium, neptunium, californium, uranium) cancerogenous effects of radon 222 and of its danghter products; (4) comparison of the hazards of various types of energy; (5) human epidemiology of radionuclide toxicity (bone cancer induction by radium, lung cancer induction by radon daughter products, liver cancer and leukaemia following the use of Thorotrast, thyroid cancer; other site of cancer induction by radionuclides) [fr

  14. Comparison of the analytical methods used to determine natural and artificial radionuclides from environmental samples by gamma, alpha and beta spectrometry

    DEFF Research Database (Denmark)

    Pöllänen, Roy; Virtanen, Sinikka; Kämäräinen, Meerit

    In CAMNAR, an extensive interlaboratory exercise on the analytical methods used to determine several radionuclides present in the environmental samples was organized. Activity concentration of different natural radionuclides, such as Rn-222, Pb-210, Po-210, K-40, Ra-226, Ra-228 and isotopes...... of uranium, in addition to artificial Cs-137 and Am-241 were analysed from lake sediment samples and drinking water. The measurement techniques were gamma-ray spectrometry, alpha spectrometry, liquid scintillation counting and inductively coupled plasma mass spectrometry. Twenty six laboratories from nine...

  15. Analysis of NSPP experiment with ART code for analyzing transport behavior of Aerosol and radionuclides

    International Nuclear Information System (INIS)

    Ishigami, Tsutomu; Kobayashi, Kensuke; Kajimoto, Mitsuhiro.

    1989-01-01

    The ART code calculates transport behavior of aerosols and radionuclides during core meltdown accidents in the light water reactors. Since aerosols play an important role in carrying fission products from the core region to the environment, the ART code includes detailed models of aerosol behavior. Aerosols including several radionuclides are classified into many groups according to the aerosol mass. The models of aerosol behavior include agglomeration processes caused by Brownian motion, aerosol settling velocity difference and turbulent flow, and natural deposition processes due to diffusion, thermophoresis, diffusiophoresis, gravitational settling and forced convection. In order to examine validity of the ART models, the NSPP aerosol experiment was analyzed. The ART calculated results showed good agreement with the experimental data. It was ascertained that aerosol growth due to agglomeration, gravitational settling, thermophoresis in an air atmosphere, and diffusiophoresis in an air-steam atmosphere were important physical phenomena in the aerosol behavior. (author)

  16. The present-day level of long-living artificial radionuclides content in mosses, lichens and needles of Siberia areas

    International Nuclear Information System (INIS)

    Strakhovenko, V.D.; Sukhorukov, F.V.; Shcherbov, B.L.

    2005-01-01

    The purpose of the paper is to estimate the present-day level of long-living artificial radionuclides activity in lichen-moss cover and needles in the Siberia region. During the expeditionary activities (1995-2004) the Lichen cover mosses and needles were sampled in the Ust'-Ordinsky and Aginsky Buryatsky autonomous regions, Altai area, Republic of Altai, Novosibirsk Region, the Yamal-Nenets Autonomous region. The identical species of lichen, mosses. needles were collected from Siberia (lichens - Cladonia, Evernia, Usnea, Parmeli; mosses - Polytrichum, Hylocomium, Pleurozium, Sphagnum; needles - Pinaceae). It was collected 6 and more lichen species from each of 18 sample sites, more than 3 Moss species from 7 sample sites, and in place of coniferous trees joint growth (a pine, a cedar, a fir, a fur-tree and a larch). The needles were selected from all trees and thus were divided into one-year-old and many-year old. The samples were analyzed in the Laboratory of Trace Elements Geochemistry and Ecogeochemistry of the UIGGM, Novosibirsk, using special sample preparation and analysis techniques. The content of 137 Cs were determined by gamma-spectrometry (analyst Stepin A.S.), 90 Sr by beta-radiometry with a radiochemical sample preparation (analyst Makeover I.V.). The data reported are evidence that a present-day level of radioactive contamination in moss-lichen cover and needles of Siberia areas corresponds to this of global background, expect for northern area of Siberia (YNAD) for which hyperactivity are determined for the each of three components. Radiocesium concentration in one-year old needles reflects a level of atmospheric intake only for accidents, for other cases the condition of current needles reflects basically radionuclide level established as the result of dynamic balance between root intake and annual biogenic abscission of needles. (author)

  17. Geochemical behavior of radionuclides and heavy metals in soils from Corumbatai River basin (SP), Brazil

    International Nuclear Information System (INIS)

    Conceicao, Fabiano Tomazini da

    2004-01-01

    The purpose of this research was to study the geochemical behavior of radionuclides and heavy metals in soils of agricultural use at Corumbatai River basin (SP). The natural concentration and variability in sedimentary rocks at Corumbatai river basin follow the trend Ca > Mg > K > Na, with the concentration of heavy metals and radionuclides. The distribution of exposure rate in soils shows the occurrence of higher values towards south of the Corumbatai river basin, region where are applied phosphate fertilizers, amendments and 'vinhaca' in sugar cane crops. Heavy metals and radionuclides incorporated in phosphate fertilizers and amendments are annually added during the fertilization process in the sugar cane crops, but if they are utilized in accordance with the recommended rate, they do not rise the concentration levels in soils up to hazards levels. Thus, they are lower transferred from soils to sugar cane at Corumbatai river basin, not offering hazard to the ecosystem and animal or human health. (author)

  18. Integrated performance assessment model for waste policy package behavior and radionuclide release

    International Nuclear Information System (INIS)

    Kossik, R.; Miller, I.; Cunnane, M.

    1992-01-01

    Golder Associates Inc. (GAI) has developed a probabilistic total system performance assessment and strategy evaluation model (RIP) which can be applied in an iterative manner to evaluate repository site suitability and guide site characterization. This paper describes one component of the RIP software, the waste package behavior and radionuclide release model. The waste package component model considers waste package failure by various modes, matrix alteration/dissolution, and radionuclide mass transfer. Model parameters can be described as functions of local environmental conditions. The waste package component model is coupled to component models for far-field radionuclide transport and disruptive events. The model has recently been applied to the proposed repository at Yucca Mountain

  19. Integrated performance assessment model for waste package behavior and radionuclide release

    International Nuclear Information System (INIS)

    Kossik, R.; Miller, I.; Cunnane, M.

    1992-01-01

    Golder Associates Inc. (GAI) has developed a probabilistic total system performance assessment and strategy evaluation model (RIP) which can be applied in an iterative manner to evaluate repository site suitability and guide site characterization. This paper describes one component of the RIP software, the waste package behavior and radionuclide release model. The waste package component model considers waste package failure by various modes, matrix alteration/dissolution, and radionuclide mass transfer. Model parameters can be described as functions of local environmental conditions. The waste package component model is coupled to component models for far-field radionuclide transport and disruptive events. The model has recently been applied to the proposed repository at Yucca Mountain

  20. A Preliminary Study of Two Different Clays for Separation of Some Artificial Radionuclides in Stimulated Waste

    International Nuclear Information System (INIS)

    Lasheen, Y.F.; Seliman, A.F.; Shehata, F.A.; Youssef, M.A.; Abo-Aly, M.

    2016-01-01

    The removal of long lived radionuclides, such as 134 Cs(I), 133 Ba(II), 90 Sr(II) and 152 Eu(III) by bentonite (W-Bent) and kaolin (S-Kaol) was studied as a function of different parameters using a batch technique. The results showed that the optimum ph was selected to be 6. Kinetically in case of W-Bent, the adsorption is heterogeneous for 134 Cs, 133 Ba and homogenous for 90 Sr and 152 Eu. The distribution coefficient values follow the order of 1 '5 2 Eu> 134 Cs> 90 Sr> 133 Ba. Langmuir, Freundlish, Dubinin-Raduskevich (D-R) and Temkin isotherm models were applied. According to the D-R model, W-Bent showed a high affinity to 152 Eu with a maximum capacity (q m = 0.43 mol/Kg) in comparison with S-Kaol (q m =0.023 mol/Kg). Also according to D-R model the adsorption energy (E> 8.0 KJ mol -1 ) that means the adsorption reaction is expected to be chemisorption. Finally both clays are cost-effective sorbent materials with an excellent adsorption capacity, but some surface modification for S-Kaol is recommended to be more effective than its natural form

  1. The distribution of artificial radionuclides in the waters of the Norwegian-Greenland Sea in 1985

    International Nuclear Information System (INIS)

    Wedekind, C.; Gabriel, H.; Goroncy, I.; Framcke, G.

    1997-01-01

    In the summer of 1985, sea water samples were taken to determine 3 H, 90 Sr, 134 Cs, 137 Cs and transuranics within a grid of 165 stations including 16 depth series down to the seafloor, covering all ice-free areas. The distribution of the activity concentrations and the nuclide ratios reveal the contamination pathway into the surface and deeper layers of the Norwegian-Greenland Sea from nuclear weapon fallout and civil nuclear technology. Moreover, the investigations show that: (1) a yearly discharge of 1 TBq (10 12 Bq) 90 Sr into the Irish Sea (English Channel) is diluted on its way to the southern Norwegian Sea, raising the concentration by about 0.04 m Bql -1 ; (2) the drift time to this sea area is around 4 years; (3) about 40% of the 137 Cs discharged does not reach the Norwegian Sea and (4) a further 30% leaves the Norwegian-Greenland Sea via the North Cape and flows into the Barents Sea. Investigations into the vertical distribution and stratification of the radioactivity indicate the time scale on which the radionuclides travel to the deeper layers. (author)

  2. Radionuclide distributions and sorption behavior in the Susquehanna--Chesapeake Bay System

    International Nuclear Information System (INIS)

    Olsen, C.R.; Larsen, I.L.; Lowry, P.D.; McLean, R.I.; Domotor, S.L.

    1989-01-01

    Radionuclides released into the Susquehanna--Chesapeake System from the Three Mile Island, Peach Bottom, and Calvert Cliffs nuclear power plants are partitioned among dissolved, particulate, and biological phases and may thus exist in a number of physical and chemical forms. In this project, we have measured the dissolved and particulate distributions of fallout 137 Cs; reactor-released 137 Cs, 134 Cs, 65 Zn, 60 Co, and 58 Co; and naturally occurring 7 Be and 210 Pb in the lower Susquehanna River and Upper Chesapeake Bay. In addition, we chemically leached suspended particles and bottom sediments in the laboratory to determine radionuclide partitioning among different particulate-sorbing phases to complement the site-specific field data. This information has been used to document the important geochemical processes that affect the transport, sorption, distribution, and fate of reactor-released radionuclides (and by analogy, other trace contaminants) in this river-estuarine system. Knowledge of the mechanisms, kinetic factors, and processes that affect radionuclide distributions is crucial for predicting their biological availability, toxicity, chemical behavior, physical transport, and accumulation in aquatic systems. The results from this project provide the information necessary for developing accurate radionuclide-transport and biological-uptake models. 76 refs., 12 figs

  3. Empirical modeling of dynamic behaviors of pneumatic artificial muscle actuators.

    Science.gov (United States)

    Wickramatunge, Kanchana Crishan; Leephakpreeda, Thananchai

    2013-11-01

    Pneumatic Artificial Muscle (PAM) actuators yield muscle-like mechanical actuation with high force to weight ratio, soft and flexible structure, and adaptable compliance for rehabilitation and prosthetic appliances to the disabled as well as humanoid robots or machines. The present study is to develop empirical models of the PAM actuators, that is, a PAM coupled with pneumatic control valves, in order to describe their dynamic behaviors for practical control design and usage. Empirical modeling is an efficient approach to computer-based modeling with observations of real behaviors. Different characteristics of dynamic behaviors of each PAM actuator are due not only to the structures of the PAM actuators themselves, but also to the variations of their material properties in manufacturing processes. To overcome the difficulties, the proposed empirical models are experimentally derived from real physical behaviors of the PAM actuators, which are being implemented. In case studies, the simulated results with good agreement to experimental results, show that the proposed methodology can be applied to describe the dynamic behaviors of the real PAM actuators. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  4. State of radionuclides in seawater. Comparison of natural stable and artificial radioactive isotope s of mercury and zinc in natural waters of the arid zone of the USSR

    International Nuclear Information System (INIS)

    Rakhmatov, U; Khikmatov, K; Kist, A.A.; Kulmatov, R.A.; Teshabaev, S.T.; Volkov, A.A.

    1986-01-01

    This paper studies the state of stable and artificial radioactive isotopes of merury and zinc in natural waters of the arid zone of the USSR by radioactivity and radiochemical methods. Convergent results have been obtained for the dissolved forms of mercury and zinc in natural waters of the arid zone in a comparison of the results of radioactivation analysis and laboratory simulation using the radionuclides mercury-203 and zinc-65

  5. Transfer of some artificial (strontium 85 and caesium 137) and natural (potasium 40 and radium 226) radionuclides from milk to its products

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Nashawati, A.; Amin, Y.; Al-Akel, B.

    2004-12-01

    Transfer of some artificial radionuclides ( 137 Cs and 85 Sr) and natural radionuclides ( 226 Ra and 40 K) from milk (cheep and cows) to its products processed according to local manufacturing procedures (home made cheese, kashkawan cheese, shelal cheese, haloom cheese, kareshah cheese, sharkasiah cheese, liquid cheese, yogurt, butter and keshdah) has been studied. The results showed that the retention percent of radium 226 in milk products has reached %100 in the home made cheese and %72 for strontium 85 in the shelal cheese and %40 for cesium 137 in yogurt and %46 for potassium 40 also in yogurt. In addition, most of the retention percent ratios of the studied radionuclides in yogurt were relatively low (about %25 and % 40 in the yogurt processed from the milk of the cows and cheep respectively) with a high processing efficiency, so that making yogurt from the contaminated milk is the best way to reduce the contamination ratio and to make use of the contaminated milk. Furthermore, home made cheese was processed with salty solutions of different concentrations and the results showed that about %90 of cesium and potassium has transferred to the salty solution of %5 soaked for 48 hours, while %40 of the radium and %80 of strontium were removed from the contaminated cheese after 48 hours soaking in a salty solution of %2.5. However, the results of the present work can be used for processing of contaminated milk with artificial radionuclides in order to be utilized. (Authors)

  6. Transfer of some artificial (226Sr and 137Cs) and natural (40K and 226Ra) radionuclides from milk to its products

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Nashawati, A.; Amin, Y.; Al-Akel, B.

    2005-01-01

    Transfer of some artificial radionuclides ( 137 Cs and 85 Sr) and natural radionuclides ( 226 Ra and 40 K) from milk (cheep and cows) to its products processed according to local manufacturing procedures (home made cheese, kashkawan cheese, shelal cheese, haloom cheese, kareshah cheese, sharkasiah cheese, liquid cheese, yogurt, butter and keshdah) has been studied. The results showed that the retention percent of radium 226 in milk products has reached %100 in the home made cheese and %72 for strontium 85 in the shelal cheese and %40 for cesium 137 in yogurt and %46 for potassium 40 also in yogurt. In addition, most of the retention percent ratios of the studied radionuclides in yogurt were relatively low (about %25 and % 40 in the yogurt processed from the milk of the cows and cheep respectively) with a high processing efficiency, so that making yogurt from the contaminated milk is the best way to reduce the contamination ratio and to make use of the contaminated milk. Furthermore, home made cheese was processed with salty solutions of different concentrations and the results showed that about %90 of cesium and potassium has transferred to the salty solution of %5 soaked for 48 hours, while %40 of the radium and %80 of strontium were removed from the contaminated cheese after 48 hours soaking in a salty solution of %2.5. However, the results of the present work can be used for processing of contaminated milk with artificial radionuclides in order to be utilized. (Authors)

  7. Radioactive contamination of the Shagan river ecosystem components with artificial radionuclides

    International Nuclear Information System (INIS)

    Subbotin, S.B.; Lukashenko, S.N.; Larionova, N.V.; Yakovenko, Yu.Yu.

    2008-01-01

    90 Sr distribution in water, it was established that the radionuclides have absolutely different sources. Whereas the nature of tritium presence in the water is quite understandable, the source of 90 Sr has not been studied yet. To determine the reasons for noticeable increase of the 90 Sr concentration in water and the ways of its proliferation into the river, additional investigations are necessary. Possible mechanisms for 90 Sr proliferation into the river may be its inflow with ground waters, plane washing off, washing out of 90 Sr from contaminated man-made soils of Atomic Lake by atmospheric precipitations. The present-day situation is complicated by active development of pasture cattle breeding and stocking of fodder crops within the bank zone of the shagan river. High tritium concentration, up to 24000 Bq/l, was also registered in the vegetation of the river-bank zone. The presence of tritium was detected in animal products produced by farms situated on the banks of the Shagan river. Tritium concentration in milk samples reaches 5.0*10 3 Bq/l, which does not exceed maximal permissible values but requires thorough investigation of the problem as tritium concentration in the Shagan waters may vary in a wide range

  8. VICTORIA: A mechanistic model of radionuclide behavior in the reactor coolant system under severe accident conditions

    International Nuclear Information System (INIS)

    Heams, T.J.; Williams, D.A.; Johns, N.A.; Mason, A.; Bixler, N.E.; Grimley, A.J.; Wheatley, C.J.; Dickson, L.W.; Osborn-Lee, I.; Domagala, P.; Zawadzki, S.; Rest, J.; Alexander, C.A.; Lee, R.Y.

    1992-12-01

    The VICTORIA model of radionuclide behavior in the reactor coolant system (RCS) of a light water reactor during a severe accident is described. It has been developed by the USNRC to define the radionuclide phenomena and processes that must be considered in systems-level models used for integrated analyses of severe accident source terms. The VICTORIA code, based upon this model, predicts fission product release from the fuel, chemical reactions involving fission products, vapor and aerosol behavior, and fission product decay heating. Also included is a detailed description of how the model is implemented in VICTORIA, the numerical algorithms used, and the correlations and thermochemical data necessary for determining a solution. A description of the code structure, input and output, and a sample problem are provided

  9. Recent developments in assessment of long-term radionuclide behavior in the geosphere-biosphere subsystem.

    Science.gov (United States)

    Smith, G M; Smith, K L; Kowe, R; Pérez-Sánchez, D; Thorne, M; Thiry, Y; Read, D; Molinero, J

    2014-05-01

    Decisions on permitting, controlling and monitoring releases of radioactivity into the environment rely on a great variety of factors. Important among these is the prospective assessment of radionuclide behavior in the environment, including migration and accumulation among and within specific environmental media, and the resulting environmental and human health impacts. Models and techniques to undertake such assessments have been developed over several decades based on knowledge of the ecosystems involved, as well as monitoring of previous radionuclide releases to the environment, laboratory experiments and other related research. This paper presents developments in the assessment of radiation doses and related research for some of the key radionuclides identified as of potential significance in the context of releases to the biosphere from disposal facilities for solid radioactive waste. Since releases to the biosphere from disposal facilities involve transfers from the geosphere to the biosphere, an important aspect is the combined effects of surface hydrology, near-surface hydrogeology and chemical gradients on speciation and radionuclide mobility in the zone in which the geosphere and biosphere overlap (herein described as the geosphere-biosphere subsystem). In turn, these aspects of the environment can be modified as a result of environmental change over the thousands of years that have to be considered in radioactive waste disposal safety assessments. Building on the experience from improved understanding of the behavior of the key radionuclides, this paper proceeds to describe development of a generic methodology for representing the processes and environmental changes that are characteristic of the interface between the geosphere and the biosphere. The information that is provided and the methodology that is described are based on international collaborative work implemented through the BIOPROTA forum, www.bioprota.org. Copyright © 2013 Elsevier Ltd. All

  10. Recent developments in assessment of long-term radionuclide behavior in the geosphere-biosphere subsystem

    International Nuclear Information System (INIS)

    Smith, G.M.; Smith, K.L.; Kowe, R.; Pérez-Sánchez, D.; Thorne, M.; Thiry, Y.; Read, D.; Molinero, J.

    2014-01-01

    Decisions on permitting, controlling and monitoring releases of radioactivity into the environment rely on a great variety of factors. Important among these is the prospective assessment of radionuclide behavior in the environment, including migration and accumulation among and within specific environmental media, and the resulting environmental and human health impacts. Models and techniques to undertake such assessments have been developed over several decades based on knowledge of the ecosystems involved, as well as monitoring of previous radionuclide releases to the environment, laboratory experiments and other related research. This paper presents developments in the assessment of radiation doses and related research for some of the key radionuclides identified as of potential significance in the context of releases to the biosphere from disposal facilities for solid radioactive waste. Since releases to the biosphere from disposal facilities involve transfers from the geosphere to the biosphere, an important aspect is the combined effects of surface hydrology, near-surface hydrogeology and chemical gradients on speciation and radionuclide mobility in the zone in which the geosphere and biosphere overlap (herein described as the geosphere-biosphere subsystem). In turn, these aspects of the environment can be modified as a result of environmental change over the thousands of years that have to be considered in radioactive waste disposal safety assessments. Building on the experience from improved understanding of the behavior of the key radionuclides, this paper proceeds to describe development of a generic methodology for representing the processes and environmental changes that are characteristic of the interface between the geosphere and the biosphere. The information that is provided and the methodology that is described are based on international collaborative work implemented through the BIOPROTA forum, (www.bioprota.org). - Highlights: • Geological

  11. Artificial emotion triggered stochastic behavior transitions with motivational gain effects for multi-objective robot tasks

    Science.gov (United States)

    Dağlarli, Evren; Temeltaş, Hakan

    2007-04-01

    This paper presents artificial emotional system based autonomous robot control architecture. Hidden Markov model developed as mathematical background for stochastic emotional and behavior transitions. Motivation module of architecture considered as behavioral gain effect generator for achieving multi-objective robot tasks. According to emotional and behavioral state transition probabilities, artificial emotions determine sequences of behaviors. Also motivational gain effects of proposed architecture can be observed on the executing behaviors during simulation.

  12. Chemical behavior of long-lived radionuclides in the marine environment

    International Nuclear Information System (INIS)

    Edgington, D.N.; Nelson, D.M.

    1983-01-01

    Measurements of long-lived radionuclides in the marine environment have provided a wealth of information regarding the physical, biological, and chemical processes which control the behavior of these and many other pollutants in the oceans. Their value as tracers for the dispersion, transport, and fate of pollutants in the oceans is largely dependent on the chemical properties of each individual radioelement. Differences in these properties, particularly in relation to their interaction with biotic or abiotic particulate matter, result in the separation of parent-daughter radioisotopes in the natural radioelement series or in changes in the ratios of fission and activation products. Such differences have provided the means to provide time scales for a variey of transport processes and to determine sedimentation rates. The properties of these radionuclides in the oceans can, in general, be predicted from the chemical properties of the stable elements. For those elements such as plutonium, for which there are no naturally-occurring stable isotopes, studies of their distribution in the oceans have provided a new important understanding of their chemical behavior. This behavior has not always agreed with what would have been predicted from laboratory studies carried out at far higher concentrations. Differences between observed distributions and laboratory predictions have highlighted the importance of correct experimental conditions in order to avoid confusing experimental artifacts. The interaction of radionuclides with particles in the oceans and marine sediments can be described in terms of simple ion exchange or adsorption equilibria

  13. Implementing Artificial Intelligence Behaviors in a Virtual World

    Science.gov (United States)

    Krisler, Brian; Thome, Michael

    2012-01-01

    In this paper, we will present a look at the current state of the art in human-computer interface technologies, including intelligent interactive agents, natural speech interaction and gestural based interfaces. We describe our use of these technologies to implement a cost effective, immersive experience on a public region in Second Life. We provision our Artificial Agents as a German Shepherd Dog avatar with an external rules engine controlling the behavior and movement. To interact with the avatar, we implemented a natural language and gesture system allowing the human avatars to use speech and physical gestures rather than interacting via a keyboard and mouse. The result is a system that allows multiple humans to interact naturally with AI avatars by playing games such as fetch with a flying disk and even practicing obedience exercises using voice and gesture, a natural seeming day in the park.

  14. Transuranic radionuclides in the Columbia River: sources, inventories, and geochemical behavior

    International Nuclear Information System (INIS)

    Beasley, T.M.

    1987-01-01

    The sources, inventories, and geochemical behavior of transuranic and other long-lived radionuclides in the lower Columbia River are summarized. Inventories have been estimated from the measured activities of the different radionuclides in 50 cores raised in 1977 and 1978, while annual export of transuranic radionuclides was determined from monthly water collections in the estuary. Continental shelf inventories of Pu and Am isotopes have been estimated using excess 210 Pb inventories and the mean 210 Pb//sup 239,240/Pu inventory ratio of 100 +/- 19 observed in representative cores raised from the shelf. Despite the substantial past addition of radioactivity to the river from operation of the plutonium production reactors at Hanford, the amounts of reactor-derived radionuclides in river sediments are small relative to fallout-derived nuclides. Erosional processes have mobilized both fallout-derived /sup 239,240/Pu and 137 Cs from the landscape to the river, but the quantities involved represent <1% of their fallout inventories within the river's drainage basin. 36 references, 6 figures, 2 tables

  15. Analysis of the behavior of radionuclides migration in fractured medium in different types of rocks matrices

    International Nuclear Information System (INIS)

    Sá, Ludimila Silva Salles de; Silveira, Cláudia Siqueira da; Lima, Zelmo Rodrigues de

    2017-01-01

    In management of radioactive wastes, the current trend is to dispose the radioactive waste for long life and high activity in permanent repositories of depth, geologically stable and low permeability. Thus, it is relevant to analyze the groundwater movement process, because the mechanism by which the radionuclides in a repository with fractures could return to the surface would be through the groundwater circulation system. A common problem encountered is the modeling of the migration of radionuclides in a fractured medium. The objective of this work is to evaluate the behavior of the migration of radionuclides in two types of rock matrix, considering the following properties: volumetric density, porosity, distribution coefficient and molecular diffusion coefficient. The physical system adopted consists of the matrix rock containing a discrete fracture in a porous medium saturated with water. The partial differential equations that describe the radionuclide movement were discretized by finite differences, and the Implicit Euler method was adopted. While for the convective term the numerical scheme of progressive differences was used

  16. Study on experimental models to analyze radionuclide migration behaviors through porous geologic media

    International Nuclear Information System (INIS)

    Tanaka, Tadao; Mukai, Masayuki

    2012-08-01

    The migration phenomenon of radionuclide through geological media such as soils and porous rocks, which is important in underground disposal of radioactive wastes, can be described by the advection-dispersion of groundwater and the interactions of radionuclide with geological media. On the other hand, to understand the migration phenomenon, actual migration data are experimentally acquired by a batch test, a column test and field trial. In the present study, experimental models about the interactions of radionuclide between the solid phase and the liquid phase were discussed systematically to interpret the migration data acquired by the various techniques and conditions. Equilibrium, reversibility, linearity, mechanism and chemistry in the interactions were considered in discussion of the experimental models. A calculation program, which can analyze migration data obtained under various conditions by applying the selected 9 types of experimental models, was maintained. The calculation program makes it be able to predict the migration behavior of radionuclide under various conditions and to decide the important parameter by a fitting analysis of the migration data. (author)

  17. Frequency-time behavior of artificially stimulated vlf emissions

    International Nuclear Information System (INIS)

    Stiles, G.S.; Helliwell, R.A.

    1975-01-01

    Artificially stimulated VLF emissions (ASE's) are emissions triggered in the magnetosphere by the whistler mode signals from VLF transmitters. These emissions may be separated into two classes, rising and falling, depending on whether the final value of df/dt is positive or negative. Several hundred ASE's triggered by three transmitters have been analyzed using the fast Fourier transform with a filter spacing of 25 Hz and an effective filter width of about 45 Hz. The study was limited to the initial frequency-time behavior of ASE's. Averages taken over many events reveal that both rising and falling tones show the same initial behavior. The emissions begin at the frequency of the triggering signal. Both tones initially rise in frequency, falling tones reversing slope at a point 25--300 Hz above the triggering signal. The slope of rising tones, particularly those triggered by NAA, often abruptly levels off in this same frequency range; as a result, a short (approximately 40 ms) plateau is formed that precedes the final rising phase. The initial frequency offset commonly observed in individual events appears to result from the frequent coincidence with this plateau of a peak in amplitude. Emissions stimulated by all three transmitters show essentially the same features; this finding indicates that their frequency behavior does not depend strongly on transmitter power. The process appears to be asymmetric in frequency; no evidence of initial growth below the triggering frequency has been found. (U.S.)

  18. Adsorption behavior of radionuclide in water containing sea salts

    International Nuclear Information System (INIS)

    Kani, Yuko; Kamoshida, Mamoru; Asano, Takashi; Tamata, Shin

    2012-01-01

    Waste water caused by the Fukushima Dai-ichi Nuclear Reactor accident contains high level radioactive material with impurities of sea water origin, such as chloride, sodium and magnesium. These impurities have the potential to inhibit the adsorption reaction of radioactive cesium and strontium to adsorbents. We have studied adsorption behavior of radioactive cesium and strontium to adsorbents to measure distribution coefficients (Kd) in the condition of different sea water concentrations. For cesium adsorption, the dependence of Kd on the sea water concentration was affected by the adsorption mechanism of adsorbent; the adsorbents which adsorbed cesium by intercalation showed less dependence of Kd on the sea water concentration, while those adsorbed cesium by ion exchange had smaller Kd with increasing the sea water concentration. For strontium adsorption, Kd decreased as the sea water concentration increased for both adsorbents which adsorbed strontium by intercalation and by ion exchange. The inhibition of intercalation and ion exchange reaction of strontium by calcium ion, that exists high concentration in sea water (400 ppm) and similar hydrated ionic radius with strontium, will cause the decrease of Kd for strontium in the sea water with higher concentration. (author)

  19. Effects of repository environment on diffusion behavior of radionuclides in buffer materials

    International Nuclear Information System (INIS)

    Kozaki, Tamotsu; Sato, Seichi

    2004-03-01

    Compacted bentonite is considered as a candidate buffer material in the geological disposal of high-level radioactive waste. An important function of the compacted bentonite is to retard the transport of radionuclides from waste forms to the surrounding host rock after degradation of an overpack. Therefore, diffusion behavior of radionuclides in the compacted bentonite has been extensively studied by many researchers for the performance assessments of the geological disposal. However, diffusion mechanism of radionuclides in the bentonite cannot be fully understood, and most experimental data have been obtained at room temperature for the bentonite saturated with low salinity water, which would disagree often with real repository conditions. In this study, therefore, apparent diffusion coefficients were determined at various diffusion temperatures for chloride ions in Na-montmorillonite samples saturated with NaCl solution of high salinity. Activation energies for the apparent diffusion were also obtained from the temperature dependence of the diffusion coefficients at different salinity. As the salinity increased, the apparent diffusion coefficients of chloride ions in montmorillonite were found to increase slightly. On the other hand, the activation energies for the chloride diffusion were found to be almost constant (approximately 12 kJ mol -1 ) and less than that in free water (17.4 kJ mol -1 ). Effects of salinity on diffusion behavior of radionuclides in montmorillonite were discussed from the viewpoints of microstructure of montmorillonite and distribution of ions in the montmorillonite. As a result, the diffusion behavior of sodium ions could be explained by the changes of the predominant diffusion process among pore water diffusion, surface diffusion, and interlayer diffusion that could be caused by the increase of salinity. (author)

  20. Radiochemical and radioecological studies of natural and artificial alpha-emitting radionuclides

    International Nuclear Information System (INIS)

    Holm, E.; Persson, B.

    1980-01-01

    Transuranium elements, including uranium and thorium, were analyzed in both marine and terrestrial samples. Vertical profiles of 239+240 Pu, 241 Am, 230 Th, and 238 U, in the Pacific, the Mediterranean, and the Atlantic, measured by different investigators, were compared. Uptake of the fallout isotopes 241 Pu, 240+239 Pu, 238 Pu, and 241 Am in the lichen - reindeer food chain was studied. Americium and thorium exhibited similar biophysical behavior in the environment and in the water column, although the settling velocity for thorium was somewhat higher. Plutonium showed similar distribution in the water columns in different waters. The fraction of ingested plutonium which was retained in the body of reindeer was in good agreement with the value of 3 x 10 -5 predicted for man. Uranium showed a constant concentration in the water column, with a low affinity to particles in the water. The high concentration of uranium in reindeer tissues depended on high intake from drinking water and foodstuffs other than lichens

  1. Tracing the origin of suspended sediment in a large Mediterranean river by combining continuous river monitoring and measurement of artificial and natural radionuclides

    International Nuclear Information System (INIS)

    Zebracki, Mathilde; Eyrolle-Boyer, Frédérique; Evrard, Olivier; Claval, David; Mourier, Brice; Gairoard, Stéphanie

    2015-01-01

    Delivery of suspended sediment from large rivers to marine environments has important environmental impacts on coastal zones. In France, the Rhone River (catchment area of 98,000 km 2 ) is by far the main supplier of sediment to the Mediterranean Sea and its annual solid discharge is largely controlled by flood events. This study investigates the relevance of alternative and original fingerprinting techniques based on the relative abundances of a series of radionuclides measured routinely at the Rhone River outlet to quantify the relative contribution of sediment supplied by the main tributaries during floods. Floods were classified according to the relative contribution of the main subcatchments (i.e., Oceanic, Cevenol, extensive Mediterranean and generalised). Between 2000 and 2012, 221 samples of suspended sediment were collected at the outlet and were shown to be representative of all flood types that occurred during the last decade. Three geogenic radionuclides (i.e., 238 U, 232 Th and 40 K) were used as fingerprints in a multivariate mixing model in order to estimate the relative contribution of the main subcatchment sources—characterised by different lithologies—in sediment samples collected at the outlet. Results showed that total sediment supply originating from Pre-Alpine, Upstream, and Cevenol sources amounted to 10, 7 and 2.10 6 tons, respectively. These results highlight the role of Pre-Alpine tributaries as the main sediment supplier (53%) to the Rhone River during floods. Other fingerprinting approaches based on artificial radionuclide activity ratios (i.e., 137 Cs/ 239+240 Pu and 238 Pu/ 239+240 Pu) were tested and provided a way to quantify sediment remobilisation or the relative contributions of the southern tributaries. In the future, fingerprinting methods based on natural radionuclides should be further applied to catchments with heterogeneous lithologies. Methods based on artificial radionuclides should be further applied to catchments

  2. Tracing the origin of suspended sediment in a large Mediterranean river by combining continuous river monitoring and measurement of artificial and natural radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Zebracki, Mathilde, E-mail: zebracki@free.fr [Laboratoire d' Etudes Radioécologiques en milieu Continental et Marin (LERCM), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Saint-Paul-lez-Durance (France); Eyrolle-Boyer, Frédérique [Laboratoire d' Etudes Radioécologiques en milieu Continental et Marin (LERCM), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Saint-Paul-lez-Durance (France); Evrard, Olivier [Laboratoire des Sciences du Climat et de l' Environnement (LSCE/IPSL), Unité Mixte de Recherche 8212 (CEA/CNRS/UVSQ), Gif-sur-Yvette (France); Claval, David [Laboratoire d' Etudes Radioécologiques en milieu Continental et Marin (LERCM), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Saint-Paul-lez-Durance (France); Mourier, Brice [Université Lyon 1, UMR 5023 Ecologie des Hydrosystèmes Naturels et Anthropisés, ENTPE, CNRS, 3, Rue Maurice Audin, F-69518 Vaulx-en-Velin (France); Université de Limoges, GRESE, EA 4330, 123 avenue Albert Thomas, 87060 Limoges (France); Gairoard, Stéphanie [Centre de Recherche et d' Enseignement de Géosciences de l' Environnement (CEREGE), Unité Mixte 34 (AMU/CNRS/IRD), Aix-en-Provence (France); and others

    2015-01-01

    Delivery of suspended sediment from large rivers to marine environments has important environmental impacts on coastal zones. In France, the Rhone River (catchment area of 98,000 km{sup 2}) is by far the main supplier of sediment to the Mediterranean Sea and its annual solid discharge is largely controlled by flood events. This study investigates the relevance of alternative and original fingerprinting techniques based on the relative abundances of a series of radionuclides measured routinely at the Rhone River outlet to quantify the relative contribution of sediment supplied by the main tributaries during floods. Floods were classified according to the relative contribution of the main subcatchments (i.e., Oceanic, Cevenol, extensive Mediterranean and generalised). Between 2000 and 2012, 221 samples of suspended sediment were collected at the outlet and were shown to be representative of all flood types that occurred during the last decade. Three geogenic radionuclides (i.e., {sup 238}U, {sup 232}Th and {sup 40}K) were used as fingerprints in a multivariate mixing model in order to estimate the relative contribution of the main subcatchment sources—characterised by different lithologies—in sediment samples collected at the outlet. Results showed that total sediment supply originating from Pre-Alpine, Upstream, and Cevenol sources amounted to 10, 7 and 2.10{sup 6} tons, respectively. These results highlight the role of Pre-Alpine tributaries as the main sediment supplier (53%) to the Rhone River during floods. Other fingerprinting approaches based on artificial radionuclide activity ratios (i.e., {sup 137}Cs/{sup 239+240}Pu and {sup 238}Pu/{sup 239+240}Pu) were tested and provided a way to quantify sediment remobilisation or the relative contributions of the southern tributaries. In the future, fingerprinting methods based on natural radionuclides should be further applied to catchments with heterogeneous lithologies. Methods based on artificial radionuclides

  3. Measurements of natural and artificial radionuclides in food samples and water for human consumption in Austria for the calculation of the ingestion dose

    International Nuclear Information System (INIS)

    Claudia Landstetter; Michael Zapletal; Merita Sinojmeri; Christian Katzlberger

    2013-01-01

    A new report on food habits of the Austrian population in the year 2006/2007 was released in 2008. Mixed diets and foodstuffs are measured within a monitoring program according to the Austrian radiation protection law, food law, and the Commission Recommendation 2000/473/Euratom on the application of Article 36 of the Euratom Treaty concerning the monitoring of the levels of radioactivity in the environment for the purpose of assessing the exposure of the population as a whole. In addition, drinking and mineral water samples are measured for natural and artificial radionuclides. The ingestion dose for the Austrian population is recalculated based on the results of these measurements, literature data, and the data of the new report on food habits. In general, the major part of the ingestion dose is caused by natural radionuclides, especially 40 K. (author)

  4. Up-to-date concentrations of long-lived artificial radionuclides in the Tom and Ob rivers in the area influenced by discharges from Siberian chemical combine

    International Nuclear Information System (INIS)

    Nikitin, A.I.; Kryshev, I.I.; Bashkirov, N.I.; Valetova, N.K.; Dunaev, G.E.; Kabanov, A.I.; Katrich, I.Yu; Krutovsky, A.O.; Nikitin, V.A.; Petrenko, G.I.; Polukhina, A.M.; Selivanova, G.V.; Shkuro, V.N.

    2012-01-01

    The Siberian Chemical Combine (SCC) is located in Seversk (formerly known as Tomsk-7) in the Tomsk Region of the Russian Federation. The main contribution of radionuclides in the SCC process water discharged into the Tom River was from the single-pass reactors, now removed from service (the last SCC reactor was shutdown on June 5, 2008). The data on the concentrations of 90 Sr, 137 Cs, 239,240 Pu and other artificial radionuclides in water, bottom sediments and flood-plain soils of the Tom and Ob rivers from Tomsk to the confluence of the rivers, are presented and discussed. The results of measurements carried out after shutdown of the last SCC single-pass reactor indicated no radiologically significant consequences of SCC activities for the studied water environment compartments. Contemporary activity concentrations of long-lived artificial radionuclides 3 H, 90 Sr, 137 Cs and 239,240 Pu in river water were below the intervention levels established by current regulations of the Russian Federation for these radionuclides. The results of 3 H analysis in water from the Tom and Samuska rivers demonstrated no inflow of contaminated formation water to surface water from the sites where liquid radioactive wastes of the SCC were injected below the surface. However, the density of flood-plain soil contamination by long-lived 137 Cs in the area influenced by SCC liquid discharges was higher than regional technogenic background. There were local flood-plain areas contaminated not only by 137 Cs, but also other gamma-emitters, such as 60 Co and 152 Eu.

  5. Vertical Distribution and Estimated Doses from Artificial Radionuclides in Soil Samples around the Chernobyl Nuclear Power Plant and the Semipalatinsk Nuclear Testing Site

    Science.gov (United States)

    Taira, Yasuyuki; Hayashida, Naomi; Tsuchiya, Rimi; Yamaguchi, Hitoshi; Takahashi, Jumpei; Kazlovsky, Alexander; Urazalin, Marat; Rakhypbekov, Tolebay; Yamashita, Shunichi; Takamura, Noboru

    2013-01-01

    For the current on-site evaluation of the environmental contamination and contributory external exposure after the accident at the Chernobyl Nuclear Power Plant (CNPP) and the nuclear tests at the Semipalatinsk Nuclear Testing Site (SNTS), the concentrations of artificial radionuclides in soil samples from each area were analyzed by gamma spectrometry. Four artificial radionuclides (241Am, 134Cs, 137Cs, and 60Co) were detected in surface soil around CNPP, whereas seven artificial radionuclides (241Am, 57Co, 137Cs, 95Zr, 95Nb, 58Co, and 60Co) were detected in surface soil around SNTS. Effective doses around CNPP were over the public dose limit of 1 mSv/y (International Commission on Radiological Protection, 1991). These levels in a contaminated area 12 km from Unit 4 were high, whereas levels in a decontaminated area 12 km from Unit 4 and another contaminated area 15 km from Unit 4 were comparatively low. On the other hand, the effective doses around SNTS were below the public dose limit. These findings suggest that the environmental contamination and effective doses on the ground definitely decrease with decontamination such as removing surface soil, although the effective doses of the sampling points around CNPP in the present study were all over the public dose limit. Thus, the remediation of soil as a countermeasure could be an extremely effective method not only for areas around CNPP and SNTS but also for areas around the Fukushima Dai-ichi Nuclear Power Plant (FNPP), and external exposure levels will be certainly reduced. Long-term follow-up of environmental monitoring around CNPP, SNTS, and FNPP, as well as evaluation of the health effects in the population residing around these areas, could contribute to radiation safety and reduce unnecessary exposure to the public. PMID:23469013

  6. Vertical distribution and estimated doses from artificial radionuclides in soil samples around the Chernobyl nuclear power plant and the Semipalatinsk nuclear testing site.

    Directory of Open Access Journals (Sweden)

    Yasuyuki Taira

    Full Text Available For the current on-site evaluation of the environmental contamination and contributory external exposure after the accident at the Chernobyl Nuclear Power Plant (CNPP and the nuclear tests at the Semipalatinsk Nuclear Testing Site (SNTS, the concentrations of artificial radionuclides in soil samples from each area were analyzed by gamma spectrometry. Four artificial radionuclides ((241Am, (134Cs, (137Cs, and (60Co were detected in surface soil around CNPP, whereas seven artificial radionuclides ((241Am, (57Co, (137Cs, (95Zr, (95Nb, (58Co, and (60Co were detected in surface soil around SNTS. Effective doses around CNPP were over the public dose limit of 1 mSv/y (International Commission on Radiological Protection, 1991. These levels in a contaminated area 12 km from Unit 4 were high, whereas levels in a decontaminated area 12 km from Unit 4 and another contaminated area 15 km from Unit 4 were comparatively low. On the other hand, the effective doses around SNTS were below the public dose limit. These findings suggest that the environmental contamination and effective doses on the ground definitely decrease with decontamination such as removing surface soil, although the effective doses of the sampling points around CNPP in the present study were all over the public dose limit. Thus, the remediation of soil as a countermeasure could be an extremely effective method not only for areas around CNPP and SNTS but also for areas around the Fukushima Dai-ichi Nuclear Power Plant (FNPP, and external exposure levels will be certainly reduced. Long-term follow-up of environmental monitoring around CNPP, SNTS, and FNPP, as well as evaluation of the health effects in the population residing around these areas, could contribute to radiation safety and reduce unnecessary exposure to the public.

  7. Vertical distribution and estimated doses from artificial radionuclides in soil samples around the Chernobyl nuclear power plant and the Semipalatinsk nuclear testing site.

    Science.gov (United States)

    Taira, Yasuyuki; Hayashida, Naomi; Tsuchiya, Rimi; Yamaguchi, Hitoshi; Takahashi, Jumpei; Kazlovsky, Alexander; Urazalin, Marat; Rakhypbekov, Tolebay; Yamashita, Shunichi; Takamura, Noboru

    2013-01-01

    For the current on-site evaluation of the environmental contamination and contributory external exposure after the accident at the Chernobyl Nuclear Power Plant (CNPP) and the nuclear tests at the Semipalatinsk Nuclear Testing Site (SNTS), the concentrations of artificial radionuclides in soil samples from each area were analyzed by gamma spectrometry. Four artificial radionuclides ((241)Am, (134)Cs, (137)Cs, and (60)Co) were detected in surface soil around CNPP, whereas seven artificial radionuclides ((241)Am, (57)Co, (137)Cs, (95)Zr, (95)Nb, (58)Co, and (60)Co) were detected in surface soil around SNTS. Effective doses around CNPP were over the public dose limit of 1 mSv/y (International Commission on Radiological Protection, 1991). These levels in a contaminated area 12 km from Unit 4 were high, whereas levels in a decontaminated area 12 km from Unit 4 and another contaminated area 15 km from Unit 4 were comparatively low. On the other hand, the effective doses around SNTS were below the public dose limit. These findings suggest that the environmental contamination and effective doses on the ground definitely decrease with decontamination such as removing surface soil, although the effective doses of the sampling points around CNPP in the present study were all over the public dose limit. Thus, the remediation of soil as a countermeasure could be an extremely effective method not only for areas around CNPP and SNTS but also for areas around the Fukushima Dai-ichi Nuclear Power Plant (FNPP), and external exposure levels will be certainly reduced. Long-term follow-up of environmental monitoring around CNPP, SNTS, and FNPP, as well as evaluation of the health effects in the population residing around these areas, could contribute to radiation safety and reduce unnecessary exposure to the public.

  8. Study on distribution and behavior of long-lived radionuclides in surface soil environment

    International Nuclear Information System (INIS)

    Morita, Shigemitsu; Watanabe, Hitoshi; Katagiri, Hiromi; Akatsu, Yasuo; Ishiguro, Hideharu

    1996-01-01

    Technetium-99 ( 99 Tc) and Neptunium-237 ( 237 Np) are important radionuclides for environmental assessment around nuclear fuel cycle facilities, because these have long-lives and relatively high mobility in the environment. Therefore, we have been studied the determination, distribution and behavior of such long-lived radionuclides in surface soil environment. A new analytical technique using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was applied to the determination of long-lived radionuclides in environmental samples. The determination method consists of dry ashing, anion exchange and solvent extraction to eliminate the interfering elements and ICP-MS measurement. The sensitivity of this method was 10 to 100,000 times higher, and the counting time was 300 to 100,000 times shorter than the conventional radioanalytical methods. The soil samples were collected at nine points and core soil sample was collected by an electric core sampler at one point. The core soil sample was divided into eight layers. The depth profiles showed that more than 90% of 99 Tc and 237 Np were retained in the surface layer up to 10cm in depth which contained much amount of organic materials. The results suggest that content of organic materials in soil is related to adsorption of 99 Tc and 237 Np onto soil. (author)

  9. Study of migration behavior of technogenic radionuclides in the Yenisey River-Kara Sea aquatic system

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, Yu.; Legin, E.; Legin, V. [Khlopin Radium Institute, St. Petersburg (Russian Federation); Shishlov, A.; Savitskii, Yu. [Krasnoyarsk Mining and Chemical Combine, Krasnoyarsk (Russian Federation); Novikov, A.; Goryachenkova, T. [Russian Academy of Sciences, Institute of Geochemistry and Analytical Chemistry, Moscow (Russian Federation)

    2001-03-01

    migrates as soluble species weakly sorbed by the solid phase, causing the observed low content of Sr-90 in flood-land deposits and bottom sediments of the Yenisey River. The indicated migration behavior of radionuclides is characteristic of the Yenisey Gulf and the adjacent part of the Kara Sea also. We made similar conclusions when studying the migration behavior of Cs-137, Pu-239,240, and Sr-90 in the Kiev reservoir (1987). The formation of radioactive flood-land deposits is provided by rapid deposition of suspended material in stagnant zones during periodical flood. Humus compounds contribute significantly to accumulation of radionuclides in the flood-land deposits and bottom sediments, which is supported by the observed correlation between the radionuclide (Pu, Am, Eu) and total organic carbon distributions in them. Radiochemical analysis of separate fractions showed that about 20% of Pu and Am are associated with the organic fraction: Pu is nearly equally distributed between humic and fulvic acid fractions, whereas Am is preferentially associated with the fulvic acid fraction (the most mobile fraction of humus matter). It was demonstrated in model experiments that the calcium-hydrocarbonate type of water of the Yenisey River causes suppression of formation of mobile fulvate complexes of hydrolyzable radionuclides and, therefore, their transfer into the aqueous phase. In combination with the observed very high distribution coefficients of the radionuclides and low content of their mobile geochemical forms in flood-land deposits of the Yenisey River this suggest that they cannot contribute somewhat significantly to the secondary radioactive contamination of the river water by all mechanisms except migration by mechanical transfer. (author)

  10. Study of migration behavior of technogenic radionuclides in the Yenisey River-Kara Sea aquatic system

    International Nuclear Information System (INIS)

    Kuznetsov, Yu.; Legin, E.; Legin, V.; Shishlov, A.; Savitskii, Yu.; Novikov, A.; Goryachenkova, T.

    2001-01-01

    migrates as soluble species weakly sorbed by the solid phase, causing the observed low content of Sr-90 in flood-land deposits and bottom sediments of the Yenisey River. The indicated migration behavior of radionuclides is characteristic of the Yenisey Gulf and the adjacent part of the Kara Sea also. We made similar conclusions when studying the migration behavior of Cs-137, Pu-239,240, and Sr-90 in the Kiev reservoir (1987). The formation of radioactive flood-land deposits is provided by rapid deposition of suspended material in stagnant zones during periodical flood. Humus compounds contribute significantly to accumulation of radionuclides in the flood-land deposits and bottom sediments, which is supported by the observed correlation between the radionuclide (Pu, Am, Eu) and total organic carbon distributions in them. Radiochemical analysis of separate fractions showed that about 20% of Pu and Am are associated with the organic fraction: Pu is nearly equally distributed between humic and fulvic acid fractions, whereas Am is preferentially associated with the fulvic acid fraction (the most mobile fraction of humus matter). It was demonstrated in model experiments that the calcium-hydrocarbonate type of water of the Yenisey River causes suppression of formation of mobile fulvate complexes of hydrolyzable radionuclides and, therefore, their transfer into the aqueous phase. In combination with the observed very high distribution coefficients of the radionuclides and low content of their mobile geochemical forms in flood-land deposits of the Yenisey River this suggest that they cannot contribute somewhat significantly to the secondary radioactive contamination of the river water by all mechanisms except migration by mechanical transfer. (author)

  11. Static and Fatigue Behavior Investigation of Artificial Notched Steel Reinforcement

    Directory of Open Access Journals (Sweden)

    Yafei Ma

    2017-05-01

    Full Text Available Pitting corrosion is one of the most common forms of localized corrosion. Corrosion pit results in a stress concentration and fatigue cracks usually initiate and propagate from these corrosion pits. Aging structures may fracture when the fatigue crack reaches a critical size. This paper experimentally simulates the effects of pitting morphologies on the static and fatigue behavior of steel bars. Four artificial notch shapes are considered: radial ellipse, axial ellipse, triangle and length-variable triangle. Each shape notch includes six sizes to simulate a variety of pitting corrosion morphologies. The stress-strain curves of steel bars with different notch shape and depth are obtained based on static tensile testing, and the stress concentration coefficients for various conditions are determined. It was determined that the triangular notch has the highest stress concentration coefficient, followed by length-variable triangle, radial ellipse and axial ellipse shaped notches. Subsequently, the effects of notch depth and notch aspect ratios on the fatigue life under three stress levels are investigated by fatigue testing, and the equations for stress range-fatigue life-notch depth are obtained. Several conclusions are drawn based on the proposed study. The established relationships provide an experimental reference for evaluating the fatigue life of concrete bridges.

  12. Analysis of nonlinear elastic behavior in miniature pneumatic artificial muscles

    Science.gov (United States)

    Hocking, Erica G.; Wereley, Norman M.

    2013-01-01

    Pneumatic artificial muscles (PAMs) are well known for their excellent actuator characteristics, including high specific work, specific power, and power density. Recent research has focused on miniaturizing this pneumatic actuator technology in order to develop PAMs for use in small-scale mechanical systems, such as those found in robotic or aerospace applications. The first step in implementing these miniature PAMs was to design and characterize the actuator. To that end, this study presents the manufacturing process, experimental characterization, and analytical modeling of PAMs with millimeter-scale diameters. A fabrication method was developed to consistently produce low-cost, high performance, miniature PAMs using commercially available materials. The quasi-static behavior of these PAMs was determined through experimentation on a single actuator with an active length of 39.16 mm (1.54 in) and a diameter of 4.13 mm (0.1625 in). Testing revealed the PAM’s full evolution of force with displacement for operating pressures ranging from 207 to 552 kPa (30-80 psi in 10 psi increments), as well as the blocked force and free contraction at each pressure. Three key nonlinear phenomena were observed: nonlinear PAM stiffness, hysteresis of the force versus displacement response for a given pressure, and a pressure deadband. To address the analysis of the nonlinear response of these miniature PAMs, a nonlinear stress versus strain model, a hysteresis model, and a pressure bias are introduced into a previously developed force balance analysis. Parameters of these nonlinear model refinements are identified from the measured force versus displacement data. This improved nonlinear force balance model is shown to capture the full actuation behavior of the miniature PAMs at each operating pressure and reconstruct miniature PAM response with much more accuracy than previously possible.

  13. Analysis of nonlinear elastic behavior in miniature pneumatic artificial muscles

    International Nuclear Information System (INIS)

    Hocking, Erica G; Wereley, Norman M

    2013-01-01

    Pneumatic artificial muscles (PAMs) are well known for their excellent actuator characteristics, including high specific work, specific power, and power density. Recent research has focused on miniaturizing this pneumatic actuator technology in order to develop PAMs for use in small-scale mechanical systems, such as those found in robotic or aerospace applications. The first step in implementing these miniature PAMs was to design and characterize the actuator. To that end, this study presents the manufacturing process, experimental characterization, and analytical modeling of PAMs with millimeter-scale diameters. A fabrication method was developed to consistently produce low-cost, high performance, miniature PAMs using commercially available materials. The quasi-static behavior of these PAMs was determined through experimentation on a single actuator with an active length of 39.16 mm (1.54 in) and a diameter of 4.13 mm (0.1625 in). Testing revealed the PAM’s full evolution of force with displacement for operating pressures ranging from 207 to 552 kPa (30–80 psi in 10 psi increments), as well as the blocked force and free contraction at each pressure. Three key nonlinear phenomena were observed: nonlinear PAM stiffness, hysteresis of the force versus displacement response for a given pressure, and a pressure deadband. To address the analysis of the nonlinear response of these miniature PAMs, a nonlinear stress versus strain model, a hysteresis model, and a pressure bias are introduced into a previously developed force balance analysis. Parameters of these nonlinear model refinements are identified from the measured force versus displacement data. This improved nonlinear force balance model is shown to capture the full actuation behavior of the miniature PAMs at each operating pressure and reconstruct miniature PAM response with much more accuracy than previously possible. (paper)

  14. A Korean radioecology model to simulate radionuclide behavior in agricultural ecosystems following a nuclear emergency and its application to countermeasures

    International Nuclear Information System (INIS)

    Hwang, W.T.; Suh, K.S.; Kim, E.H.; Han, M.H.; Lee, H.S.; Lee, C.W.

    2003-01-01

    A Korean radioecology model to simulate radionuclide behavior in agricultural ecosystems has been developed as a module for evaluating the ingestion dose in a Korean real-time dose assessment system FADAS, which evaluates the comprehensive radiological consequences in an accidental release of radionuclides to the environment. Using the predictive results of a Korean radioecology model, a methodology for the optimization of countermeasures has been designed based on a cost-benefit analysis. In this manuscript, a Korean radioecology model including agricultural countermeasures was introduced, and discussed with the sample calculations for the postulated accidental release of radionuclides to the environment. (author)

  15. Investigations and technical reviews on the reliability of prediction for migration behavior of radionuclides (H15)

    International Nuclear Information System (INIS)

    Tachikawa, Hirokazu

    2004-02-01

    The research plan of the validation on effects of colloids and organic materials drawn up by the Japan Nuclear Fuel Cycle Development Institute and its' research outcome were reviewed comprehensively by an expert committee established in the Nuclear Safety Research Association. Additionally, experimental investigations for the migration behavior of actinide elements and fission products in engineering barrier and natural barrier medias, and for solution chemistry of them were carried out and discussed by the committee, in order to enhance the reliability of prediction for migration behavior of radionuclides. The subjects investigated by the expert committee are as follows: (1) Research on solubility products of An(III) hydroxide. (2) Diffusion and electromigration behavior of plutonium in buffer material. (3) Analysis of the nuclide solubility in compacted bentonite. (4) Survey of the actual contamination by alpha emitters in steel materials. (author)

  16. Migration of 137Cs artificial radionuclide in the valley of the Takhtakushuk river of the Degelen massif

    International Nuclear Information System (INIS)

    Panitskij, A.V.

    2005-01-01

    Study of horizontal and vertical radionuclide distribution in the valley of the Takhtakushuk River of the 'Degelen' Massif is carried out in the framework of ecological and biological investigations of soil and plant cover within radioactive contaminated areas, and radionuclide migration in biological chain 'soil - plant - animal'. For the first time, the pool-type method was used in the studies of soil of the valley that allows tracing solid and liquid substances migrating by means of surface and soil drainage from its head to final part. This paper presents some physical and chemical properties of the study landscape's soils, radionuclide content in soil genetic horizons of the valley. The study results showed that major mass of 137 Cs radionuclide is sorbed by soil humus and fine-dispersed clay particles of grass soils within the valley. (author)

  17. Behavior of radionuclides and stable elements in the ecosystem in brackish Lake Obuchi

    International Nuclear Information System (INIS)

    Kondo, Kunio; Ueda, Shinji; Kawabata, Hitoshi; Hasegawa, Hidenao

    1998-01-01

    The behaviors and movements of radionuclides in a brackish environment, Lake Obuchi and its ecosystem were investigated with an aim to evaluate the safety of radioactive materials discharged into the lake. the organic materials in the sediment samples taken from Lake Obuchi were mainly composed of plant planktons and contained various radionuclides; 0.12-1.08 μg/g of 232 Th, 1.69-2.44 μg/g of 238 U, 0.0112-0.0176 Bq/g dry weight. The concentration of stable element was 145.6-357.3 μg/g for Mn, 82.5-128.2 μg/g for Sr, 0.81-1.65 μg/g for Cs and 11.2-16.5 μg/g dry weight for Pb. Plant planktons were found to mediate the accumulation of elements into lake sediments. Therefore, the species composition, distribution and ecological positioning of those planktons were important factors for the behaviors and movements of such elements. Then, the relationship between the concentrations of 137 Cs and Cs was studied with phytoplankton and a positive correlation (r=0.95) was found at both concentrations, suggesting that the adsorptions of the two elements onto the lake sediments were similar. (M.N.)

  18. Worldwide Open Proficiency Test: Determination of Natural and Artificial Radionuclides in Moss-Soil and Water IAEA-CU-2009-03

    International Nuclear Information System (INIS)

    2012-01-01

    Reliable determination of natural and artificial radionuclides in environmental samples is necessary to comply with radiation protection and environmental regulations. The IAEA assists Member State laboratories in maintaining and improving their readiness by producing reference materials, by developing standardized analytical methods, and by conducting interlaboratory comparisons and proficiency tests as tools for quality control. To fulfil this obligation and ensure a reliable, worldwide, rapid and consistent response, the IAEA Terrestrial Environment Laboratory in Seibersdorf, Austria, organizes interlaboratory comparisons and proficiency tests. This summary report presents the results of the worldwide proficiency test IAEA-CU-2009- 03 on the determination of natural and artificial radionuclides in moss-soil and spiked water. The methodologies, data evaluation approach, summary evaluation of each nuclide and individual evaluation reports for each laboratory are also described. This proficiency test was designed to identify analytical problems, to support Member State laboratories to improve the quality of their analytical results and maintain their accreditation, and to provide a regular forum for discussion and technology transfer in this area. The number of samples, their matrix interferences and the concentration levels of the analytes were designed in a way that enables identification of potential analytical problems.

  19. A predictive model for the behavior of radionuclides in lake systems

    International Nuclear Information System (INIS)

    Monte, L.

    1993-01-01

    This paper describes a predictive model for the behavior of 137Cs in lacustrine systems. The model was tested by comparing its predictions to contamination data collected in various lakes in Europe and North America. The migration of 137Cs from catchment basin and from bottom sediments to lake water was discussed in detail; these two factors influence the time behavior of contamination in lake water. The contributions to the levels of radionuclide concentrations in water, due to the above factors, generally increase in the long run. The uncertainty of the model, used as a generic tool for prediction of the levels of contamination in lake water, was evaluated. Data sets of water contamination analyzed in the present work suggest that the model uncertainty, at a 68% confidence level, is a factor 1.9

  20. Kinetic regularities of change in the concentration of radionuclides in the Georgian tea content

    International Nuclear Information System (INIS)

    Mosulishvili, L.M.; Katamadze, N.M.; Shoniya, N.I.; Ginturi, Eh.N.

    1990-01-01

    The paper is concerned with the results of a study of behavior of artificial radionuclides in Georgian tea technological products after the accident at the Chernobyl Nuclear Station. A partial contribution of the activity of radionuclides 141 Ce, 140 La, 103 Ru, 106 Ru, 140 Ba, 137 Cs, 95 Nb, 95 Zr, 134 Cs and 90 Sr to the total activity to Georgian tea samples. Maximum tolerated concentrations of radionuclides were assessed provided average annual tea consumption per capita was 1 kg. The maximum of solubility in the water phase falls on Cs radionuclides. The regularities of migration of half-lived radionuclides 3 yrs. After the Chernobyl accident were established

  1. Studies on migration behavior of radionuclides under reducing conditions in JNC

    International Nuclear Information System (INIS)

    Kitamura, A.; Sato, H.

    2002-01-01

    Japan Nuclear Cycle Development Institute (JNC) has performed extensive researches and developments to investigate the geochemistry and radionuclide migration in buffer materials and geosphere. Experimental and modeling studies have been carried out related to the geological disposal of high-level radioactive waste (HLW) as a link in the chair of a follow-up of the second progress report, which has explained in the technical feasibility of HLW geological disposal in Japan. In this paper, three experimental studies on solubility, sorption and diffusion of radionuclides under reducing conditions for assuring the reliability and for improving the quality of the databases are introduced. Solubility and sorption behavior of neptunium (Np) have been studied under reducing conditions in carbonate media. For the solubility study, thermodynamic equilibrium constants of carbonatohydroxo complexes of Np(IV) have been determined from a solubility measurement in alkaline solutions. For the sorption study, distribution coefficient (K d ) of Np onto smectite has been determined in weak alkaline solutions under reducing conditions in carbonate media. For the diffusion study, apparent diffusivity (D a ) of selenium (Se) in compacted bentonite have been determined under reducing conditions as a function of silica sand content and temperature

  2. Work behaviors of artificial muscle based on cation driven polypyrrole.

    Science.gov (United States)

    Fujisue, Hisashi; Sendai, Tomokazu; Yamato, Kentaro; Takashima, Wataru; Kaneto, Keiichi

    2007-06-01

    A soft actuator mimicking natural muscles (artificial muscle) has been developed using a flexible conducting polymer of polypyrrole films, which were driven by electrical stimulus in a saline solution. The work characteristics were studied under various load stresses and found to behave like natural muscles. The artificial muscles shrunk and stiffened by the positive electrical stimulus by 2-3% at the maximum force of 5 MPa, and relaxed by application of negative voltages. At larger load stresses, the artificial muscle shrunk slowly as natural muscles do. The driving current also lasted longer at larger loads, indicating that the muscle sensed the magnitude of the load stress. During contraction of the muscle, the conversion efficiency from the electrical input and mechanical output energies was estimated to be around 0.06%. The maximum volumetric work was approximately estimated to be 100 kJ m(-3). These figures are unexpectedly small compared with those of natural muscles.

  3. Radionuclide data

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Chapter 8 presents tables on selected alpha, beta, gamma and x-ray emitters by increasing energy; information on specific activity for selected radionuclides; naturally occurring radionuclides; the natural decay series; and the artificially produced neptunium series. A table of alpha emitters is listed by increasing atomic number and by energy. The table of β emitters presented is useful in identifying β emitters whose energies and possibly half-lives have been determined by standard laboratory techniques. It is also a handy guide to β-emitting isotopes for applications requiring specific half-lives and/or energies. Gamma rays for radionuclides of importance to radiological assessments and radiation protection are listed by increasing energy. The energies and branching ratios are important for radionuclide determinations with gamma spectrometry detectors. This section also presents a table of x-ray energies which are useful for radiochemical analyses. A number of nuclides emit x-rays as part of their decay scheme. These x-rays may be counted with Ar proportional counters, Ge planar or n-type Ge co-axial detectors, or thin crystal NaI(T1) scintillation counters. In both cases, spectral measurements can be made and both qualitative and quantitative information obtained on the sample. Nuclear decay data (energy and probability by radiation type) for more than one hundred radionuclides that are important to health physicists are presented in a schematic manner

  4. Distribution of artificial radionuclides in abandoned cattle in the evacuation zone of the Fukushima Daiichi nuclear power plant.

    Directory of Open Access Journals (Sweden)

    Tomokazu Fukuda

    Full Text Available The Fukushima Daiichi Nuclear Power Plant (FNPP accident released large amounts of radioactive substances into the environment. In order to provide basic information for biokinetics of radionuclides and for dose assessment of internal exposure brought by the FNPP accident, we determined the activity concentration of radionuclides in the organs of 79 cattle within a 20-km radius around the FNPP. In all the specimens examined, deposition of Cesium-134 ((134Cs, half-life: 2.065 y and (137Cs (30.07 y was observed. Furthermore, organ-specific deposition of radionuclides with relatively short half-lives was detected, such as silver-110m ((110mAg, 249.8 d in the liver and tellurium-129m ((129mTe, 33.6 d in the kidney. Regression analysis showed a linear correlation between the radiocesium activity concentration in whole peripheral blood (PB and that in each organ. The resulting slopes were organ dependent with the maximum value of 21.3 being obtained for skeletal muscles (R(2 = 0.83, standard error (SE = 0.76. Thus, the activity concentration of (134 Cs and (137Cs in an organ can be estimated from that in PB. The level of radioactive cesium in the organs of fetus and infants were 1.19-fold (R(2 = 0.62, SE = 0.12, and 1.51-fold (R(2 = 0.70, SE = 0.09 higher than that of the corresponding maternal organ, respectively. Furthermore, radiocesium activity concentration in organs was found to be dependent on the feeding conditions and the geographic location of the cattle. This study is the first to reveal the detailed systemic distribution of radionuclides in cattle attributed to the FNPP accident.

  5. Release and transport of artificial radionuclides from nuclear weapons related activities in the Ob River, Siberia over the course of the nuclear age

    International Nuclear Information System (INIS)

    Sayles, F.L.; Kenna, T.C.; Livingston, H.D.

    1999-01-01

    Studies of sediment cores from lakes on the flood plain of the Ob River, Siberia have been used to develop a history of the release, transport, and deposition of artificial radionuclides related to the development and testing of nuclear weapons over the duration of the nuclear age (∼1950 to the present) in this major Arctic river system. The Ob is of particular importance in this regard as two of the former Soviet Union's major weapons production plants, Mayak and Tomsk-7, and the Semipalatinsk test site are located within the Ob drainage basin. Accidents and intentional releases of radionuclides at both plants have been substantial, raising the issue of transport throughout this extensive river system as well as delivery to the Arctic Ocean. Our studies have included determining sediment profiles of 239,240 Pu, 137 Cs, and the natural nuclide 210 Pb and its parent 226 Ra in a number of cores from the Ob delta, as well as analysis of 239 Pu, 240 Pu, and 237 Np. The latter provide sensitive measures of the presence of non-fallout materials derived from weapons production activities

  6. Extraction behavior of radionuclides in the first separation cycle in reprocessing

    International Nuclear Information System (INIS)

    Uchiyama, Gunzo; Asakura, Toshihide; Hotoku, Shinobu; Watanabe, Makio; Fujine, Sachio; Nemoto, Hideyuki.

    1997-01-01

    The chemical flowsheet experiment by using three mixer-settlers was conducted to study the extraction behavior of radionuclides such as technetium, neptunium, iodine, zirconium and ruthenium in the uranium-TBP-nitric acid solution system in the simulated first separation cycle in current reprocessing plants. The following results were obtained: More than 99.999% of the total uranium fed to the co-decontamination step in the simulated dissolver solution was extracted by TBP solvent. About 90% of the total uranium was recovered in the uranium back-extraction step. About 30% of the total neptunium fed to the co-decontamination step was in the raffinate solution in the co-decontamination step, 12% of the total neptunium was in the Tc solution in the Tc separation step and about 58% of the total neptunium was in the Pu solution in the U/Pu partitioning step. As for technetium, about 99% of the total technetium was extracted by TBP in the co-decontamination step, 86% of the total technetium was scrubbed with high acid nitric acid solution in the Tc separation step and 13% of the total technetium was in the Pu solution in the U/Pu partitioning step. As for the other radionuclides, 99% of the total ruthenium and 93% of the total zirconium were distributed into the raffinate in the co-decontamination step. In the Tc separation step, ruthenium was scrubbed more effectively than ruthenium with high acid solution. About 45% of the total iodine fed to the co-decontamination step was vaporized during the experiment. Iodine in aqueous solutions in the flowsheet was mainly in volatile I 2 form. Iodine was rarely distributed into the aqueous solution and was distributed with TBP solvent in the flowsheet. Significant amounts of iodine was contained in the washed solvent. (author)

  7. Log-linear model based behavior selection method for artificial fish swarm algorithm.

    Science.gov (United States)

    Huang, Zhehuang; Chen, Yidong

    2015-01-01

    Artificial fish swarm algorithm (AFSA) is a population based optimization technique inspired by social behavior of fishes. In past several years, AFSA has been successfully applied in many research and application areas. The behavior of fishes has a crucial impact on the performance of AFSA, such as global exploration ability and convergence speed. How to construct and select behaviors of fishes are an important task. To solve these problems, an improved artificial fish swarm algorithm based on log-linear model is proposed and implemented in this paper. There are three main works. Firstly, we proposed a new behavior selection algorithm based on log-linear model which can enhance decision making ability of behavior selection. Secondly, adaptive movement behavior based on adaptive weight is presented, which can dynamically adjust according to the diversity of fishes. Finally, some new behaviors are defined and introduced into artificial fish swarm algorithm at the first time to improve global optimization capability. The experiments on high dimensional function optimization showed that the improved algorithm has more powerful global exploration ability and reasonable convergence speed compared with the standard artificial fish swarm algorithm.

  8. Log-Linear Model Based Behavior Selection Method for Artificial Fish Swarm Algorithm

    Directory of Open Access Journals (Sweden)

    Zhehuang Huang

    2015-01-01

    Full Text Available Artificial fish swarm algorithm (AFSA is a population based optimization technique inspired by social behavior of fishes. In past several years, AFSA has been successfully applied in many research and application areas. The behavior of fishes has a crucial impact on the performance of AFSA, such as global exploration ability and convergence speed. How to construct and select behaviors of fishes are an important task. To solve these problems, an improved artificial fish swarm algorithm based on log-linear model is proposed and implemented in this paper. There are three main works. Firstly, we proposed a new behavior selection algorithm based on log-linear model which can enhance decision making ability of behavior selection. Secondly, adaptive movement behavior based on adaptive weight is presented, which can dynamically adjust according to the diversity of fishes. Finally, some new behaviors are defined and introduced into artificial fish swarm algorithm at the first time to improve global optimization capability. The experiments on high dimensional function optimization showed that the improved algorithm has more powerful global exploration ability and reasonable convergence speed compared with the standard artificial fish swarm algorithm.

  9. The behavior of radionuclides in the soils of Rocky Flats, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Litaor, M I [Tel-Hai Rodman Coll., Upper Galilee (Israel); Barth, G; Zika, E M; Litus, G; Moffitt, J; Daniels, H [Colorado Univ., Civil and Environmental Engineering Dept., Boulder, CO (United States)

    1998-05-01

    Radionuclide contamination of soils in Rocky Flats, Colorado, resulted from leaking drums of Pu-contaminated oil stored at an outdoor area. To evaluated the mechanisms of radionuclide transport from the contaminated soils to groundwater, an advanced monitoring system was installed across a toposequence. The impact of natural rain, snowmelt, and large-scale rain simulations on the mobility and distribution of the radionuclides in soil interstitial water was studied. The distribution of radionuclides during the monitoring period from 1993 to 1995 suggested that Pu-239 + 240 and Am-241 are largely immobile in semi-arid soils. Fractionation of Pu-239 + 240 and Am-241 to different particle sizes in the soil interstitial water suggested that most of the radionuclides (83-97%) were associated with suspended particles, whereas the level of radionuclides associated with colloidal (0.45 {mu}m > X > 1 nm) and nonfilterable (< 1 nm) fractions ranged from 1.5 to 15%. (author).

  10. Continuous measurements of natural radionuclides on air-borne dust using β-α correlated events. Towards on-line detection of artificial radionuclides in nuclear-fuel reprocessing and its related facilities

    International Nuclear Information System (INIS)

    Hashimoto, Tetsuo; Ishiyama, Hisanobu; Itou, Shigeki

    2008-01-01

    -nuclides; the detection limit was estimated to be several percents of radioactivity against natural α-nuclides. The present method will be preferable to the in situ or remote monitoring of artificial radionuclides from nuclear facilities and so on. (author)

  11. Radiochemical Procedures Used at Iaea-Ilmr Monaco for Measuring Artificial Radionuclides Resulting from the Chernobyl Accident

    Science.gov (United States)

    Ballestra, S.; Gastaud, J.; Lopez, J. J.

    The Chernobyl accident which occurred on 26 April 1986 resulted in relatively high levels of radioactive fallout over the major part of Europe. Air filter and precipitation samples enabled us to follow the contamination from the accident. In addition contamination was also monitored in selected environmental samples such as seaweeds, sea water, sediment, soil, suspended matter and biological material from the Mediterranean. All samples were counted on Ge(Li) or Ge(HP) detectors to determine the type and quantity of gamma emitting radionuclides and plutonium, americium and curium isotopes were separated and measured using radiochemical techniques and alpha counting. Increased atmospheric radioactivity from the Chernobyl accident was first detected by observing increased activity levels on air filters taken on April 30, 1986, with maximum activities occurring during 1-3 May. Most of the radionuclides initially measured were short-lived fission products. Cs-137 was one of the predominant isotope in the fallout debris and its deposition at Monaco due to Chernobyl was estimated to be around 1400 Bq m-2, which represents 25-40% of the integrated fallout at this latitude. The deposition of Pu-239+240 was much smaller and was estimated to be around 10 mBq m-2 or only 0.1% of the total deposition from nuclear weapon testing.

  12. Modeling the thermotaxis behavior of C.elegans based on the artificial neural network.

    Science.gov (United States)

    Li, Mingxu; Deng, Xin; Wang, Jin; Chen, Qiaosong; Tang, Yun

    2016-07-03

    ASBTRACT This research aims at modeling the thermotaxis behavior of C.elegans which is a kind of nematode with full clarified neuronal connections. Firstly, this work establishes the motion model which can perform the undulatory locomotion with turning behavior. Secondly, the thermotaxis behavior is modeled by nonlinear functions and the nonlinear functions are learned by artificial neural network. Once the artificial neural networks have been well trained, they can perform the desired thermotaxis behavior. Last, several testing simulations are carried out to verify the effectiveness of the model for thermotaxis behavior. This work also analyzes the different performances of the model under different environments. The testing results reveal the essence of the thermotaxis of C.elegans to some extent, and theoretically support the research on the navigation of the crawling robots.

  13. Intercomparison measurements of surface soil contamination with in-situ gamma ray spectrometry. Pt.1. Artificial radionuclides

    International Nuclear Information System (INIS)

    Winkelmann, I.

    1994-01-01

    This intercomparison program was performed by the Federal Office of Radiation Protection in October 1993. It includes seven laboratory teams from five countries and is applied on a pasture in southern Germany having an undisturbed soil profile. The location was chosen because of its relatively high 137 Cs-soil contamination caused by the Chernobyl accident - up to 50 kBq/m 2 . The deposition of 134 Cs and 137 Cs was determined. The comparison demonstrated a good agreement between results from different labs. Additionally, the dose rate at all marked locations was measured and compared to the dose rate of individual radionuclides calculated from the measured spectra. A relatively good agreement was obtained. It is shown that the main contribution to the total dose rate of 70 nSv/h is made by 137 Cs with a value of 5 nSv/h. 4 figs., 2 tabs., 3 refs. (orig.)

  14. Environmental behavior of anionic radionuclides with special regard to their reactions within the soil

    International Nuclear Information System (INIS)

    Burkhardt, J.

    1983-04-01

    This report describes the behavior of radioiodine in inanimate nature (atmosphere, soil) as example for radioisotopes that exist in the environment in anionic form. Because of the significance of the longlived radionuclide Iodine-129 for the radiation exposure of man, the study is focussing on the retention process of radioiodine in soil. For a better understanding of some observations on the reaction of radioiodine in soil recorded in literature, the first chapter is dealing with the mechanisms of anion absorption in soil in general. Another chapter explores possible reactions of radioiodine in the atmosphere, based on the assumption that the chemophysical form of radioiodine deposited in soil is not necessarily identical to its original form at the time of release. Further discussed are the major reaction partners of iodine in soil and simultaneously occurring reaction mechanisms as well as the significance of soil types for radioiodine depositions in the soil. Since Iodine-129 is stored in the upper soil layer for a long period of time, due to its extremely long halflife, it may be periodically available to vegetation. The last chapter demonstrates on some examples, which uncertainty factors in the nature may influence the validity of the estimation of radiation exposures from Iodine-129 in the soil by means of an effective residence time. (orig.) [de

  15. Migration behavior and sorption mechanisms of radionuclides in sedimentary sand stones

    International Nuclear Information System (INIS)

    Tanaka, Tadao; Kamiyama, Hideo; Sriyotha, K.

    1993-05-01

    The influence of crushed particle size and weathering of sedimentary rock on migration behavior and sorption mechanisms of 60 Co, 85 Sr and 137 Cs has been investigated by using the fresh sand stones (classified into two particle size ranges of 1 ∼ 3 mm and 2 , KCl, NH 2 OH-HCl, K-oxalate and H 2 O 2 solutions were carried out, to elucidate their dominated sorption mechanisms. Distribution coefficient values of the all three radionuclides, Kds, for the sand stone of 1 ∼ 3 mm was smaller than that of 85 Sr, and the same irreversible sorptions as the selective sorption of Co onto manganese oxides and fixation of Cs by the layer silicate for 60 Co and 137 Cs, respectively. Larger sorbability of the weathered sand stone was explained to be related to an increase of amounts of the effective sorption site, such as cation exchangeable site, calcite, smectite and manganese oxides, which was possibly caused from metamorphism induced by weathering the fresh sand stone. (author)

  16. Distribution and behavior of radionuclides and stable elements in Lake Obuchi

    International Nuclear Information System (INIS)

    Ueda, Shinji; Hasegawa, Hidenao; Hisamatsu, Shun'ichi; Inaba, Jiro

    2000-01-01

    Distribution and behavior of radionuclides and related stable elements in the lake water of brackish Lake Obuchi were investigated by field observations. Concentrations of 238 U and stable elements were measured at various points in the lake, and compiled to obtain the elemental distributions and variation characteristics. The concentrations of 238 U in the lake water were higher in areas nearer to the Pacific Ocean, and correlated well with those of Na, K, Ca, Mg and Sr (r = 0.86 to 0.92). These observations implied that 238 U in the lake originated from seawater. The bottom layer water was reductive during July and September (stratified period) in deep areas (> 3 m). In this condition, concentrations of PO 4 3- -P, NH 4 + -N, Fe and Mn in the water increased. Concentration ratios of 238 U to those of Na strongly suggested the following conclusions. The concentrations of 238 U in the turn-over period were represented by a simple mixture of seawater and fresh water. However, in the stratified period, part of the 238 U was lost from the seawater near the bottom of the lake due to the reductive condition. (author)

  17. VICTORIA: A mechanistic model of radionuclide behavior in the reactor coolant system under severe accident conditions. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Heams, T J [Science Applications International Corp., Albuquerque, NM (United States); Williams, D A; Johns, N A; Mason, A [UKAEA, Winfrith, (England); Bixler, N E; Grimley, A J [Sandia National Labs., Albuquerque, NM (United States); Wheatley, C J [UKAEA, Culcheth (England); Dickson, L W [Atomic Energy of Canada Ltd., Chalk River, ON (Canada); Osborn-Lee, I [Oak Ridge National Lab., TN (United States); Domagala, P; Zawadzki, S; Rest, J [Argonne National Lab., IL (United States); Alexander, C A [Battelle, Columbus, OH (United States); Lee, R Y [Nuclear Regulatory Commission, Washington, DC (United States)

    1992-12-01

    The VICTORIA model of radionuclide behavior in the reactor coolant system (RCS) of a light water reactor during a severe accident is described. It has been developed by the USNRC to define the radionuclide phenomena and processes that must be considered in systems-level models used for integrated analyses of severe accident source terms. The VICTORIA code, based upon this model, predicts fission product release from the fuel, chemical reactions involving fission products, vapor and aerosol behavior, and fission product decay heating. Also included is a detailed description of how the model is implemented in VICTORIA, the numerical algorithms used, and the correlations and thermochemical data necessary for determining a solution. A description of the code structure, input and output, and a sample problem are provided.

  18. Research on sorption behavior of radionuclides under shallow land environment. Mechanism and standard methodologies for measurement of distribution coefficients of radionuclides

    International Nuclear Information System (INIS)

    Sakamoto, Yoshiaki; Tanaka, Tadao; Takebe, Shinichi; Nagao, Seiya; Ogawa, Hiromichi; Komiya, Tomokazu; Hagiwara, Shigeru

    2001-01-01

    This study consists of two categories' research works. One is research on sorption mechanism of radionuclides with long half-life, which are Technetium-99, TRU elements and U series radionuclides, on soil and rocks, including a development of database of distribution coefficients of radionuclides. The database on the distribution coefficients of radionuclides with information about measurement conditions, such as shaking method, soil characteristics and solution composition, has been already opened to the public (JAERI-DATABASE 20001003). Another study is investigation on a standard methodology of the distribution coefficient of radionuclide on soils, rocks and engineering materials in Japan. (author)

  19. Behavioral Finance and Agent-Based Artificial Markets

    NARCIS (Netherlands)

    M. Lovric (Milan)

    2011-01-01

    textabstractStudying the behavior of market participants is important due to its potential impact on asset prices and the dynamics of financial markets. The idea of individual investors who are prone to biases in judgment and who use various heuristics, which might lead to anomalies on the market

  20. Artificial Neural Networks: A New Approach for Predicting Application Behavior. AIR 2001 Annual Forum Paper.

    Science.gov (United States)

    Gonzalez, Julie M. Byers; DesJardins, Stephen L.

    This paper examines how predictive modeling can be used to study application behavior. A relatively new technique, artificial neural networks (ANNs), was applied to help predict which students were likely to get into a large Research I university. Data were obtained from a university in Iowa. Two cohorts were used, each containing approximately…

  1. The power of negative feedback from an artificial agent to promote energy saving behavior

    NARCIS (Netherlands)

    Midden, Cees; Ham, Jaap; Marcus, A.

    2014-01-01

    In this paper we analyze the role of negative feedback as provided by artificial agents. We examine the hypothesis that negative feedback offers substantial potential to enhance persuasive interventions aimed to change behavior. This hypothesis is tested based on a review of several studies using

  2. Survey of natural and artificial radionuclide contents in soil samples from some areas of the AP Kosovo (Serbia)

    International Nuclear Information System (INIS)

    Adrovic, Feriz; Kosanovic, Katica; Jakupi, Bajram; Krstic, Gordana; Filipovic, Radmila

    2008-01-01

    After the war conflict in the Autonomous Province of Kosovo and Metohija (Serbia), NATO published data on locations where they used ammunition with depleted uranium. In these regions there were localized points of concentrated contamination, so called 'contamination points'. Taking into consideration the amounts of depleted uranium ammunition used by the NATO, obviously the number of these points in the area of Kosovo and Metohija is not negligible. Within the past 7 years there have been conducted various radiological and other surveys in this area. Majority of these surveys were focused around contamination points. The fact is that so far there has been surveyed only a small percentage of the contaminated area in this region, and apparently there are more contamination points outside the surveyed area. Taking into account the mobility of depleted uranium from contaminated areas by various transportation processes (underground waters, winds and diverse mechanical contacts of people, animals, and other activities), the idea of this work was to investigate possible contamination from depleted uranium not only at the locations indicated and published by the NATO in their reports, but also in the wider area around the zones of NATO strikes. In this paper we presented results of gamma spectrometry analysis of soil samples from wider area of the Autonomous Province of Kosovo and Metohija. We used semiconductor HpGe detector with 30% relative efficiency and the resolution FWHM(1332 keV)=1,78 keV. Spectral analysis were made on the basis of the present gamma lines, using a software package. The activity concentrations of the investigated radionuclides in the soil samples were ranged in the following intervals: 226 Ra from 19 to 55 Bq/kg, 235 U from 1,2 to 4,6 Bq/kg, 238 U from 26 to 95 Bq/kg, 40 K from 83 to 648 Bq/kg, 137 Cs from 1 to 176 Bq/kg. (author)

  3. Artificial dirt: microfluidic substrates for nematode neurobiology and behavior.

    Science.gov (United States)

    Lockery, S R; Lawton, K J; Doll, J C; Faumont, S; Coulthard, S M; Thiele, T R; Chronis, N; McCormick, K E; Goodman, M B; Pruitt, B L

    2008-06-01

    With a nervous system of only 302 neurons, the free-living nematode Caenorhabditis elegans is a powerful experimental organism for neurobiology. However, the laboratory substrate commonly used in C. elegans research, a planar agarose surface, fails to reflect the complexity of this organism's natural environment, complicates stimulus delivery, and is incompatible with high-resolution optophysiology experiments. Here we present a new class of microfluidic devices for C. elegans neurobiology and behavior: agarose-free, micron-scale chambers and channels that allow the animals to crawl as they would on agarose. One such device mimics a moist soil matrix and facilitates rapid delivery of fluid-borne stimuli. A second device consists of sinusoidal channels that can be used to regulate the waveform and trajectory of crawling worms. Both devices are thin and transparent, rendering them compatible with high-resolution microscope objectives for neuronal imaging and optical recording. Together, the new devices are likely to accelerate studies of the neuronal basis of behavior in C. elegans.

  4. Effect of microorganisms on the chemical behavior of radionuclides in the environment

    International Nuclear Information System (INIS)

    Amachi, Seigo

    2004-01-01

    Microorganisms are affecting the fate of various radionuclides in the environment through processes such as sorption, accumulation, reduction, leaching and volatilization. We have studied on the microbial influences on the chemical behavior of iodine in the environment, and have isolated various microorganisms which can mediate volatilization, accumulation and oxidation of iodine. We found that iodine-volatilizing bacteria are distributed widely in the environment, and are very diverse group of bacteria. From gas chromatographic analyses, volatile iodine species produced by bacteria was identified as methyl iodide (CH 3 I). Radiotracer experiments were carried out to estimate bacterial contribution to the volatilization of iodine from soils and seawaters. In soil samples, bacteria were considered to play major roles in iodine volatilization since the addition of bacterial inhibitor almost completely inhibited the volatilization. On the other hand, in seawater samples, both bacterial and fungal (or algal) contributions were suggested. We also isolated iodine-accumulating bacteria and iodine-oxidizing bacteria from the environment. Iodine-accumulating bacteria were isolated from marine sediments, and 16S ribosomal DNA sequences showed that they are close to common marine bacteria Flexibacter sp. During the cultivation with iodide ion, they accumulated iodide intracellularly at a concentration that is more than 1,000 times higher than the culture medium. Iodide uptake by iodine-accumulating bacteria was found to occur biologically, and the uptake was specific for iodide but not for iodate. Iodine-oxidizing bacteria, which can mediate iodide (I - ) oxidation to molecular iodine (I 2 ), were phylogenetically divided into two groups within alpha-Proteobacteria, and iodide oxidation was mediated by an extracellular enzyme protein. (author)

  5. Determination of the activity concentration levels of the artificial radionuclide137Cs in soil samples collected from Qatar using high-resolution gamma-ray spectrometry

    Science.gov (United States)

    Al-Sulaiti, Huda; Nasir, Tabassum; Al Mugren, K. S.; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bradley, D. A.; Bukhari, S.; Regan, P. H.; Santawamaitre, T.; Malain, D.; Habib, A.; Al-Dosari, Hanan; Daar, Eman

    2016-09-01

    The goal of this study was to establish the first baseline measurements for radioactivity concentration of the artificial radionuclide 137Cs in soil samples collected from the Qatarian peninsula. The work focused on the determination of the activity concentrations levels of man-made radiation in 129 soil samples collected across the landscape of the State of Qatar. All the samples were collected before the most recent accident in Japan, “the 2011 Fukushima Dai-ichi nuclear power plant accident”. The activity concentrations have been measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector situated in a low-background environment with a copper inner-plated passive lead shield. A radiological map showing the activity concentrations of 137Cs is presented in this work. The concentration wasfound to range from 0.21 to 15.41 Bq/kg. The highest activity concentration of 137Cs was observed in sample no. 26 in North of Qatar. The mean value was found to be around 2.15 ± 0.27 Bq/kg. These values lie within the expected range relative to the countries in the region. It is expected that this contamination is mainly due to the Chernobyl accident on 26 April 1986, but this conclusion cannot be confirmed because of the lack of data before this accident.

  6. Analysis of radionuclide behavior in a BWR Mark-II containment under severe accident management condition in low pressure sequence

    International Nuclear Information System (INIS)

    Funayama, Kyoko; Kajimoto, Mitsuhiro; Nagayoshi, Takuji; Tanaka, Nobuo

    1999-01-01

    In the Level 2 PSA program at INS/NUPEC, MELCOR1.8.3 is extensively applied to analyze radionuclide behavior of dominant sequences. In addition, the revised source terms provided in the NUREG-1465 report have been also discussed to examine the potential of the radionuclides release to the environment in the conventional siting criteria. In the present study, characteristics of source terms to the environment were examined comparing with results by the Hypothetical Accident (LOCA), NUREG-1465 and MELCOR1.8.3. calculation for a typical BWR with a Mark-II containment in order to assure conservatives of the Hypothetical Accident in Japan. Release fractions of iodine to the environment for the Hypothetical Accident and NUREG-1465, which used engineering models for predicting radionuclide behaviors, were about 10 -4 and 10 -6 of core inventory, respectively, while the best estimate MELCOR1.8.3 code predicted 10 -9 of iodine to the environment. The present study showed that the engineering models in the Hypothetical Accident or NUREG-1465 have large conservatives to estimate source term of iodine to the environment. (author)

  7. Speciation analysis of radionuclides

    International Nuclear Information System (INIS)

    Salbu, B.

    2010-01-01

    Full text: Naturally occurring and artificially produced radionuclides in the environment can be present in different physico-chemical forms (i. e. radionuclide species) varying in size (nominal molecular mass), charge properties and valence, oxidation state, structure and morphology, density, complexing ability etc. Low molecular mass (LMM) species are believed to be mobile and potentially bioavailable, while high molecular mass (HMM) species such as colloids, polymers, pseudocolloids and particles are considered inert. Due to time dependent transformation processes such as mobilization of radionuclide species from solid phases or interactions of mobile and reactive radionuclide species with components in soils and sediments, however, the original distribution of radionuclides deposited in ecosystems will change over time and influence the ecosystem behaviour. To assess the environmental impact from radionuclide contamination, information on radionuclide species deposited, interactions within affected ecosystems and the time-dependent distribution of radionuclide species influencing mobility and biological uptake is essential. The development of speciation techniques to characterize radionuclide species in waters, soils and sediments should therefore be essential for improving the prediction power of impact and risk assessment models. The present paper reviews fractionation techniques which should be utilised for radionuclide speciation purposes. (author)

  8. Effects of microstructure of clay on diffusion behavior of radionuclides in buffer materials

    International Nuclear Information System (INIS)

    Ohashi, Hiroshi; Sato, Seichi; Kozaki, Tamotsu

    2001-03-01

    Diffusion behavior of radionuclides in compacted bentonite plays an important role in the performance assessment of bentonite buffer material in geological disposal of high-level radioactive waste. Microstructure of bentonite is considered to be one of the key parameters to affect on the diffusion behavior. In this study, therefore, two kinds of montmorillonite (major clay mineral of bentonite) with different particle sizes were prepared, and characterized with several methods. In addition, the apparent and effective diffusion coefficients of HTO, Cl - , and Cs + were determined using the montmorillonite samples with different particle sizes and dry densities. In the sample characterization, the specific surface areas of montmorillonite samples with different particle sizes were determined by the BET and the EGME methods, and the particle size distributions of each sample were analyzed by laser diffraction/scattering particle size analysis. Microstructure of the samples was also observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The BET method gave a higher specific surface area of the fine grained sample than of the coarse sample, while the EGME method gave same values for both samples. The laser diffraction/scattering particle size analysis using ethanol as a dispersion medium gave different particle size distributions, but when the samples were dispersed in water with Na 6 (PO 3 ) 6 , the particle size distributions were similar. These findings indicate that the montmorillonite layers, which compose the montmorillonite particles, have the same size, even if the particle sizes of the samples are different. In the diffusion experiments, it was found that the apparent diffusion coefficients of HTO and Cl - for the fine grained sample were higher than for the coarse grained sample at two dry densities, 1.0 and 1.8 Mg m -3 , while the opposite particle size effect was observed for Cs + ions. These findings cannot be explained by changes

  9. Workplace injuries, safety climate and behaviors: application of an artificial neural network.

    Science.gov (United States)

    Abubakar, A Mohammed; Karadal, Himmet; Bayighomog, Steven W; Merdan, Ethem

    2018-05-09

    This article proposes and tests a model for the interaction effect of the organizational safety climate and behaviors on workplace injuries. Using artificial neural network and survey data from 306 metal casting industry employees in central Anatolia, we found that an organizational safety climate mitigates workplace injuries, and safety behaviors enforce the strength of the negative impact of the safety climate on workplace injuries. The results suggest a complex relationship between the organizational safety climate, safety behavior and workplace injuries. Theoretical and practical implications are discussed in light of decreasing workplace injuries in the Anatolian metal casting industry.

  10. Effects of radionuclide decay on waste glass behavior: A critical review

    International Nuclear Information System (INIS)

    Wronkiewicz, D.J.

    1993-12-01

    This paper is an extension of a chapter in an earlier report [1] that provides an updated review on the status of radiation damage problems in nuclear waste glasses. This report will focus on radiation effects on vitrified borosilicate nuclear waste glasses under conditions expected in the proposed Yucca mountain repository. Radiation effects on high-level waste glasses and their surrounding repository environment are important considerations for radionuclide immobilization because of the potential to alter the glass stability and thereby influence the radionuclide retentive properties of this waste form. The influence of radionuclide decay on vitrified nuclear waste may be manifested by several changes, including volume, stored energy, structure, microstructure, mechanical properties, and phase separation. Radiation may also affect the composition of aqueous fluids and atmospheric gases in relatively close proximity to the waste form. What is important to the radionuclide retentive properties of the repository is how these radiation effects collectively or individually influence the durability and radionuclide release from the glass in the event of liquid water contact

  11. Study on behavior of long-lived radionuclides in soil environment

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Shigemitsu; Watanabe, Hitoshi; Katagiri, Hiromi; Akatsu, Yasuo [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works

    1996-04-01

    Distribution of {sup 99}Tc, {sup 239,240}Pu and {sup 237}Np in soil in Japan was measured. Dependency of concentration on physical and chemical properties of soil was studied. High sensitivity inductively coupled plasma mass spectroscopy was applied to the quantitative analysis of long-lived radionuclides. (J.P.N.)

  12. Balance and behavior of gaseous radionuclides released during initial fast reactor fuel reprocessing operations

    International Nuclear Information System (INIS)

    Leudet, A.; Goumondy, J.P.; Charrier, G.

    1985-10-01

    Five pins from the fast reactor Phenix are cut and dissolved in a specially designed cell for the accurate determination of gas released during the operation. Amount and activity of gaseous radionuclides: Kr, Xe, Kr-85, I, I-129, H-3 and C-14 are determined in the fuel pins and also their distribution between shearing and dissolution [fr

  13. Modeling radionuclide Cs and C dynamics in an artificial forest ecosystem in Japan -FoRothCs ver1.0-

    Directory of Open Access Journals (Sweden)

    Kazuya eNishina

    2015-09-01

    Full Text Available Predicting the environmental fate of Cs radionuclides in forest ecosystems is important for the effective management and assessment of radioactively contaminated forest areas. A large proportion of the radioactively contaminated areas in Japan consist of forest ecosystems, and most of these areas are artificial forests that are used for timber production (e.g., Japanese cedar (Cryptomeria japonica and red pine (Pinus densiflora. Determining the long-term redistribution of 137Cs in forest ecosystems is important for estimating human doses and understanding the ecological impacts and challenges associated with managing contaminated forests. To facilitate the management and 137Cs decontamination of these forests, we developed a new open-source 137Cs cycling model, ForRothCs, that considers C cycling within forests, as well as biomass production and soil decomposition processes. For the 137Cs inventory, this model estimates the dynamics (Bq m−2 and activity (Bq kg−2 of 137Cs on a decadal time scale, primarily in the leaves, branches, stems, litter layer, and the soil. This model is based on the biomass production and the dynamics of the C cycle models. We tested the model by considering a simple scenario of forest management, i.e., thinning and harvesting, for the first five years following a fallout event. The results showed that these activities have a limited impact on the 137Cs inventory due to the rapid migration of 137Cs from vegetation to soil. Our projections also showed the examined forest management practices resulted in reduced litterfall, which in turn reduced C input to the forest floor and increased the concentration of 137Cs in the litterfall and soil organic layer. Although further validation of the ForRothCs model is required using field observation data, the model can be used to evaluate long-term 137Cs dynamics associated with commonly used forest and decontamination management scenarios.

  14. Radionuclide fixation mechanisms in rocks

    International Nuclear Information System (INIS)

    Nakashima, S.

    1991-01-01

    In the safety evaluation of the radioactive waste disposal in geological environment, the mass balance equation for radionuclide migration is given. The sorption of radionuclides by geological formations is conventionally represented by the retardation of the radionuclides as compared with water movement. In order to quantify the sorption of radionuclides by rocks and sediments, the distribution ratio is used. In order to study quantitatively the long term behavior of waste radionuclides in geological environment, besides the distribution ratio concept in short term, slower radionuclide retention reaction involving mineral transformation should be considered. The development of microspectroscopic method for long term reaction path modeling, the behavior of iron during granite and water interaction, the reduction precipitation of radionuclides, radionuclide migration pathways, and the representative scheme of radionuclide migration and fixation in rocks are discussed. (K.I.)

  15. Estimating the behavior of RC beams strengthened with NSM system using artificial neural networks

    Directory of Open Access Journals (Sweden)

    Seyed Rohollah Hosseini Vaez

    2017-12-01

    Full Text Available In the last decade, conventional materials such as steel and concrete are being replaced by fiber reinforced polymer (FRP materials for the strengthening of concrete structures. Among the strengthening techniques based on Fiber Reinforced Polymer composites, the use of near-surface mounted (NSM FRP rods is emerging as a promising technology for increasing flexural and shear strength of deficient concrete, masonry and timber members. An artificial neural network is an information processing tool that is inspired by the way biological nervous systems (such as the brain process the information. The key element of this tool is the novel structure of the information processing system. In engineering applications, a neural network can be a vector mapper which maps an input vector to an output one. In the present study, a new approach is developed to predict the behavior of strengthened concrete beam using a large number of experimental data by applying artificial neural networks. Having parameters used as input nodes in ANN modeling such as elastic modulus of the FRP reinforcement, the ratio of the steel longitudinal reinforcement, dimensions of the beam section, the ratio of the NSM-FRP reinforcement and characteristics of concrete, the output node was the flexural strength of beams. The idealized neural network was employed to generate empirical charts and equations to be used in design. The aim of this study is to investigate the behavior of strengthened RC beam using artificial neural networks.

  16. Analysis of micro-failure behaviors in artificial muscles based on fishing line and sewing thread

    Science.gov (United States)

    Xu, J. B.; Cheng, K. F.; Tu, S. L.; He, X. M.; Ma, C.; Jin, Y. Z.; Kang, X. N.; Sun, T.; Zhang, Y.

    2017-06-01

    The aim of the present study was to discuss a new and effective method for testing artificial muscles based on micro-failure behaviors analysis. Thermo-mechanical actuators based on fishing line and sewing thread, also, the capability of responding to ambient temperature variations producing a large amount of shrinkage ratio of a resulting variation in longitudinal length. The minimum micro-failure value is 0.02μm and the maximum value is 1.72μm with nylon twist pattern. The discovery of an innovative effective testing of artificial muscles based on polymeric fibers specimens on micro-failure, rupture, slippage, etc. This research finds out a micro-failure behavior analysis of thermo-mechanical actuators based on fishing line and sewing thread. The specimens show large deformations when heated together with warping performance in terms of shrinkage of energy and densities. With the purpose of providing useful analysis data for the further technology applications, we attempt micrometre-sized artificial muscles which were also tested was readily accessible and also can be applied to other polymeric fibers. Effective use of this technique achievement relies on rotate speed, temperature and tensile direction. The results of the tensile testing experiments were outstanding with respect to some important issues related to the response of micro-structure, twisted polymeric fibers and shrinkage ratio.

  17. Sorption behavior of cesium, cobalt and europium radionuclides onto hydroxyl magnesium silicate

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, Mostafa M.; Holiel, M.; Ahmed, I.M. [Atomic Energy Authority, Cairo (Egypt). Hot Laboratories and Waste Management Center

    2016-07-01

    The radioactive wastes from different activities have to be safely disposed of and isolated from the human environment. The retardation of radioactive materials by designed barriers is originally controlled by the sorption ability of the mineral compositions. In this work, a naturally available mineral composite, a hydroxyl magnesium silicate (HMS) was investigated as potential natural inorganic sorbent for the retention of long-lived radionuclides ({sup 134}Cs, {sup 60}Co and {sup 152+154}Eu) from aqueous solutions. The factors affecting the sorption process, such as contact time and pH were evaluated. Furthermore X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), differential thermal and thermogravimetry analyses (DTA/TGA) measurements were examined in order to assess the physicochemical properties of the magnesium silicate mineral. Langmuir and Freundlich isotherms fitted the result s substantially better than the Flory-Huggins isotherm and the sorption was found to follow pseudo-first order kinetic model. The proposed mineral has been successfully applied for the sorption of {sup 134}Cs, {sup 60}Co and {sup 152+154}Eu radionuclides from real radioactive waste. The results indicated that about 97.4-99% of {sup 134}Cs, {sup 60}Co and {sup 152+154}Eu radionuclides were efficiently retained onto the HMS mineral. Based on the results obtained, it can be concluded that the HMS mineral is an economic and efficient retaining material for environmental hazardous migration and/or leakage of some radionuclides such as {sup 134}Cs, {sup 60}Co and {sup 152+154}Eu and trivalent actinide ({sup 241}Am, {sup 242m}Am and {sup 243}Am) ions. Therefore, this study could be used as a starting point to establish and consider that mineral as an engineered barrier around the disposal facilities at the nuclear activity centres.

  18. Chapter 13. Radionuclides in medicine

    International Nuclear Information System (INIS)

    Toelgyessy, J.; Harangozo, M.

    2000-01-01

    This is a chapter of textbook of radioecology for university students. In this chapter authors deal with problems connected with using of radionuclides in medicine. Methods of treatment with using of radionuclides are reviewed. Chapter consists of next parts: (1) Remotion of thyroid gland; (2) Treatment of cerebrally tumour in nuclear reactor; (3) Artificial heart

  19. Artificial neural networks in prediction of mechanical behavior of concrete at high temperature

    International Nuclear Information System (INIS)

    Mukherjee, A.; Nag Biswas, S.

    1997-01-01

    The behavior of concrete structures that are exposed to extreme thermo-mechanical loading is an issue of great importance in nuclear engineering. The mechanical behavior of concrete at high temperature is non-linear. The properties that regulate its response are highly temperature dependent and extremely complex. In addition, the constituent materials, e.g. aggregates, influence the response significantly. Attempts have been made to trace the stress-strain curve through mathematical models and rheological models. However, it has been difficult to include all the contributing factors in the mathematical model. This paper examines a new programming paradigm, artificial neural networks, for the problem. Implementing a feedforward network and backpropagation algorithm the stress-strain relationship of the material is captured. The neural networks for the prediction of uniaxial behavior of concrete at high temperature has been presented here. The results of the present investigation are very encouraging. (orig.)

  20. Artificial radionuclides in the oceans

    International Nuclear Information System (INIS)

    Templeton, W.L.

    1979-10-01

    The report highlights the areas of major contributions that the nuclear era has made to the understanding of oceanography and the marine sciences, and in particular the application to the public health problems that arise through anthropogenic exploitation of the oceans for the disposal of radioactive materials

  1. Forecast for Artificial Muscle Tremor Behavior Based on Dynamic Additional Grey Catastrophe Prediction

    Directory of Open Access Journals (Sweden)

    Yu Fu

    2018-02-01

    Full Text Available Recently, bio-inspired artificial muscles based on ionic polymers have shown a bright perspective in engineering and medical research, but the inherent tremor behavior can cause instability of output response. In this paper, dynamic additional grey catastrophe prediction (DAGCP is proposed to forecast the occurrence time of tremor behavior, providing adequate preparation time for the suppression of the chitosan-based artificial muscles. DAGCP constructs various dimensions of time subsequence models under different starting points based on the threshold of tremor occurrence times and peak-to-peak values in unit time. Next, the appropriate subsequence is selected according to grey correlation degree and prediction accuracy, then it is updated with the newly generated values to achieve a real-time forecast of forthcoming tremor time. Compared with conventional grey catastrophe prediction (GCP, the proposed method has the following advantages: (1 the degradation of prediction accuracy caused by the immobilization of original parameters is prevented; (2 the dynamic input, real-time update and gradual forecast of time sequence are incorporated into the model. The experiment results show that the novel DAGCP can predict forthcoming tremor time earlier and more accurately than the conventional GCP. The generation mechanism of tremor behavior is illustrated as well.

  2. Comportamento de fungos e de sementes de feijoeiro durante o teste de envelhecimento artificial Behavior of fungi and of bean seeds during the artificial aging test

    Directory of Open Access Journals (Sweden)

    MONALISA ALVES DINIZ DA SILVA

    2000-03-01

    Full Text Available O teste de envelhecimento artificial, recomendado para avaliar o vigor de lotes de sementes, apresenta variabilidade em seus resultados; a ação dos fungos é considerada uma das causas dessa variabilidade. Este trabalho objetivou verificar os efeitos de diferentes períodos de envelhecimento artificial, no comportamento fisiológico de sementes do feijoeiro e dos fungos Aspergillus spp., Penicillium spp., Fusarium oxysporum e Colletotrichum lindemuthianum, inoculados artificialmente. Foram conduzidos testes de sanidade, germinação, tetrazólio, emergência, condutividade elétrica e lixiviação de potássio. As respostas obtidas, dependentes da duração do período de envelhecimento, indicaram efeitos da espécie fúngica presente. Concluiu-se que o teste de envelhecimento artificial associa a expressão de causas fisiológicas e sanitárias, o que prejudica a interpretação dos dados obtidos; a presença de fungos, principalmente de Aspergillus spp., pode ser considerada como capaz de interferir de modo negativo no desempenho das sementes envelhecidas artificialmente.Although recommended for evaluation of seed lot vigor, artificial aging test shows results variability for reasons yet to be elucidated. Seed-fungi association is considered one of the causes responsible for such variation. The goal of this work was to verify the effects of periods of artificial aging on bean seed behavior and on Aspergillus spp., Penicillium spp., Fusarium oxysporum and Colletotrichum lindemuthianum fungi artificially inoculated by contact method. Health, germination, tetrazolium, emergence, electrical conductivity and potassium leaching tests were performed for seed behavior evaluation. The answers achieved, besides dependable on the aging time period, indicated the effect of fungi species associated to the seed. The artificial aging test was found to be associated with the expression of physiological and sanitary causes that interfere with data

  3. Leaching behavior of some radionuclides from cement matrix incorporating exhausted polymeric resins

    International Nuclear Information System (INIS)

    Abou-Mesalam, M.M.

    2002-01-01

    Exhausted poly(acrylamide-acrylic acid) impregnated with zirconium phosphate {P(AM-AA)-ZrP} produced from the treatment process of radioactive liquid waste was incorporated in different types of cement to prevent widespreading of radionuclides into the human environment. The rates at which 60 Co, 65 Zn and 152,154 Eu are leached from Ordinary Portland Cement (OPC) and Blast Furnace Slag Cement (BFSC) were measured. From the leaching data the leach coefficients of 60 Co, 65 Zn and 152,154 Eu were determined and were found to vary between 1.62 x 10 -8 to 7.06 x 10 -10 cm 2 /day and 1.01 x 10 -8 to 8.93 x 10 -9 cm 2 /day in OPC and BFSC, respectively. In general, the radionuclide leaching rates followed the order: 152,154 Eu > 65 Zn > 60 Co. The leach coefficient was found to be dependent on the composition of the leachants and varied in the order: distilled water > ground water > synthetic sea water. The effect of NaNo 3 concentration in the wastes on the leach coefficient of 60 Co from OPC was also studied. (author)

  4. Distribution and behavior of radionuclides in the coastal ecosystem in Rokkasho Village

    International Nuclear Information System (INIS)

    Kondo, Kunio; Kawabata, Hitoshi; Ueda, Shinji; Hasegawa, Hidenao; Inaba, Jiro

    2001-01-01

    The aim of the present study was to elucidate, through both field studies and laboratory experiments, the mechanism for the elution of radionuclides and other materials from suspended organic matter that accompanies the decomposition of organic matter, consisting mainly of phytoplankton, in the coastal sea region off Rokkasho Village. The effect of water temperature on the decomposition rate of organic matter suspended in seawater was investigated in laboratory experiments. The results demonstrated that the decomposition process was divided into two steps for each of the items of dry weight (SS), particulate organic carbon (POC), and particulate organic nitrogen (PON). The first step in decomposition progressed rapidly over several days. The second step of decomposition occurred at a slower rate than the first step. The decomposition rate of organic material was found to be strongly dependent on temperature, with decomposition progressing faster the higher the temperature. The amounts of Mn, Zn, Cu, Pb, Sn, Ni, Be, V, Ti, Ba, Cr, Sr, and the radionuclides 232 Th and 238 Ur eluted from organic matter by decomposition (30 days) of suspended organic matter were in the range of 31-72% of the amounts contained in the organic matter. (author)

  5. Artificial intelligence exploration of unstable protocells leads to predictable properties and discovery of collective behavior.

    Science.gov (United States)

    Points, Laurie J; Taylor, James Ward; Grizou, Jonathan; Donkers, Kevin; Cronin, Leroy

    2018-01-30

    Protocell models are used to investigate how cells might have first assembled on Earth. Some, like oil-in-water droplets, can be seemingly simple models, while able to exhibit complex and unpredictable behaviors. How such simple oil-in-water systems can come together to yield complex and life-like behaviors remains a key question. Herein, we illustrate how the combination of automated experimentation and image processing, physicochemical analysis, and machine learning allows significant advances to be made in understanding the driving forces behind oil-in-water droplet behaviors. Utilizing >7,000 experiments collected using an autonomous robotic platform, we illustrate how smart automation cannot only help with exploration, optimization, and discovery of new behaviors, but can also be core to developing fundamental understanding of such systems. Using this process, we were able to relate droplet formulation to behavior via predicted physical properties, and to identify and predict more occurrences of a rare collective droplet behavior, droplet swarming. Proton NMR spectroscopic and qualitative pH methods enabled us to better understand oil dissolution, chemical change, phase transitions, and droplet and aqueous phase flows, illustrating the utility of the combination of smart-automation and traditional analytical chemistry techniques. We further extended our study for the simultaneous exploration of both the oil and aqueous phases using a robotic platform. Overall, this work shows that the combination of chemistry, robotics, and artificial intelligence enables discovery, prediction, and mechanistic understanding in ways that no one approach could achieve alone.

  6. Hormones and the Evolution of Complex Traits: Insights from Artificial Selection on Behavior.

    Science.gov (United States)

    Garland, Theodore; Zhao, Meng; Saltzman, Wendy

    2016-08-01

    Although behavior may often be a fairly direct target of natural or sexual selection, it cannot evolve without changes in subordinate traits that cause or permit its expression. In principle, changes in endocrine function could be a common mechanism underlying behavioral evolution because they are well positioned to mediate integrated responses to behavioral selection. More specifically, hormones can influence both motivational (e.g., brain) and performance (e.g., muscles) components of behavior simultaneously and in a coordinated fashion. If the endocrine system is often "used" as a general mechanism to effect responses to selection, then correlated responses in other aspects of behavior, life history, and organismal performance (e.g., locomotor abilities) should commonly occur because any cell with appropriate receptors could be affected. Ways in which behavior coadapts with other aspects of the phenotype can be studied directly through artificial selection and experimental evolution. Several studies have targeted rodent behavior for selective breeding and reported changes in other aspects of behavior, life history, and lower-level effectors of these organismal traits, including endocrine function. One example involves selection for high levels of voluntary wheel running, one aspect of physical activity, in four replicate High Runner (HR) lines of mice. Circulating levels of several hormones (including insulin, testosterone, thyroxine, triiodothyronine) have been characterized, three of which-corticosterone, leptin, and adiponectin-differ between HR and control lines, depending on sex, age, and generation. Potential changes in circulating levels of other behaviorally and metabolically relevant hormones, as well as in other components of the endocrine system (e.g., receptors), have yet to be examined. Overall, results to date identify promising avenues for further studies on the endocrine basis of activity levels. © The Author 2016. Published by Oxford University

  7. Quality assurance in the analysis of natural radionuclides - measures and results

    Energy Technology Data Exchange (ETDEWEB)

    Bothe, M [Nuclear Engineering and Analytics Rossendorf, Inc. (VKTA), Dresden (Germany)

    1997-03-01

    In the Laboratory for Environmental and Radionuclide Analytics we analyze several natural and also some artificial radionuclides in different materials. For the determination of radionuclides we use various analytical methods. (orig./DG)

  8. Comparative behavior of three long-lived radionuclides in forest ecosystems

    International Nuclear Information System (INIS)

    Auerbach, S.I.

    1986-01-01

    This paper deals with studies in three forest ecosystems in eastern Tennessee, an area of rich temperate deciduous forests, sometimes referred to as mixed mesophytic forests. Two of these forest ecosystems were contaminated as a result of waste disposal operations. The third was experimentally tagged with millicurie quantities of 137 Cs. One of these ecosystems is a floodplain forest that is typical of this region. This forest has been growing on alluvial soils since 1944. Prior to that time the area was a temporary holding pond within White Oak Creek which received radioactive effluents from ORNL. Radiocesium was deposited in the pond sediments as were 90 Sr, 239 Pu, 241 Am, and other radionuclides. The dam which created the pond failed in late 1944, and the area was allowed to revert to natural conditions. The result was the development of a floodplain forest consisting of three different forest communities. The soils are fertile alluvials representative of bottomlands. The overstory tree species are principally ash, sycamore, boxelder, willow, and sweetgum (Fraxinus americana L., Plantanus occidentalis L., Acer negundo L., Salix nigra Marsh, and Liquidambar styraciflua L., respectively)

  9. Radionuclides in foods

    International Nuclear Information System (INIS)

    1994-01-01

    This report contains data on the levels of radionuclides in the UK foodchain. Most data derive from monitoring programmes that exist around nuclear sites, and in some cases date back to the 1960s. Some comparative data from site operator and government-run programmes are included. Data from monitoring undertaken after the Chernobyl accident are summarised. General monitoring of the foodchain for both artificial and natural radionuclides, and the results of relevant government-sponsored research are also described. The report includes basic information on radioactivity in the environment, radiation protection standards and describes what measures are taken to routinely monitor the foodchain and assess public risk. (Author)

  10. Geochemistry and behavior of Natural radionuclides in the Layers Exploitable Phosphate field MerahLahrachOuladAbdoun's Basin - Morocco

    International Nuclear Information System (INIS)

    Fait, E.; Fakhi, S.

    2012-01-01

    The present work is part of research developed on the behavior and the exchange of metals in solid-liquid's interface. It is about clarifying the distribution of stable metals especially radioactive, in this context radiometric analyzes and elementary has been done on all layers exploitable phosphate aged Maastrichtian (-70.6 million years) - Lutetian (-40.4 My) in the center of OuladAbdoun's basin, MerahLahrach's area. The specific activities of 238U, 235U and 232Th and their respective descendants were determined directly by spectrometry gamma and radio-chemically by spectrometry alpha. The results found show an enrichment of radionuclides in the deeper layers who came from the leaching of upper layers. The maximum specific activity of uranium is stored in the deeper layers (layer 3 aged Maastrichtian) who aren't very rich on phosphorus (22.4% P), however the 238U was reached up to 2066144 Bq/kg, equivalent of 16 11 ppm, the layer 1's median presents the low concentrations with 857 39Bq/Kg, equivalent of 703 ppm. The average specific activity of radionuclides identified in the series of exploited phosphates (238U, 232Th, 226Ra, 214Pb and 40K) are respectively (125572Bq/Kg; 309 Bq/Kg; 1285207 Bq/Kg; 102252 Bq/kg and 207 Bq/Kg). The study of mobility and / or accumulation accomplished by exploiting the variation of isotopic ratios 230Th/238U, 234U/238U and 232Th/238U as a function on the depth of phosphate's layers and the lithology of these samples, has allowed to identify the phenomena of exchanging between the layers of the system studied.

  11. The thorium phosphate diphosphate as matrix for radioactive waste conditioning: radionuclide immobilization and behavior under irradiation

    International Nuclear Information System (INIS)

    Pichot, Erwan

    1999-01-01

    The aim of this work was to perform successively the decontamination of liquid solutions and the final immobilization of radionuclide storage using the same matrix. For this, thorium phosphate-diphosphate (TPD) of the formula Th 4 P 6 O 23 , is proposed as a very resistant to water corrosion matrix. A new compound, thorium phosphate hydrogeno-phosphate (TPHP) of the formula Th 2 (PO 4 ) 2 (HPO 4 ), nH 2 O with n=3-7 was synthesized and characterized. Heated at 1100 deg.C it is transformed into the TDP. Ion exchange properties of TPHP were investigated. The exchange yields of imponderable caesium, strontium and americium ion onto TPHP (NaNO 3 0.1 M media at pH=6) are equal to 60% for the first one and 100% for the two others. The results interpreted in terms of ion-exchange led to determine selectivity coefficient values for each cation and suggested that only hydrated ions are exchanged. While the TPD is proposed for the high level nuclear waste storage, the irradiation effects, particularly structural modifications were studied using both γ irradiation and charged particle irradiation. ESR and TL methods were carried out in order to identify radicals created during gamma radiation exposure. Correlation between ESR and TL experiments performed at room temperature clearly show three of PO 3 2- species and one POO· species of free radicals. We have shown that Au-ion irradiation in the range of MeV energy involved TPD structure and chemical modifications. Important sputtering was interpreted in terms of local thermal chemical decomposition. We have shown, at room temperature, that the amorphization dose for heavy ion irradiation is between 0.1 to 0.4 dpa. (author)

  12. Electrochemical and corrosion behavior of two chromium dental alloys in artificial bioenvironments

    Directory of Open Access Journals (Sweden)

    Banu Alexandra

    2017-01-01

    Full Text Available The purpose of this study is to compare the corrosion and tarnish behavior of NiCrMo and CoCrMo cast dental alloys in artificial bio environments. The cobalt chromium alloys are known and used in dentistry for many years, but its difficult machinability because of the strength and hardness, is an argument for scientists to study alternative materials with comparable biocompatibility. On the other hand, for dentistry devices beside corrosion behavior is important the aesthetic so, the used alloys have to preserve their shining and do not stain. The corrosion resistance has been evaluated using the Atomic mass spectroscopy method for ion release determination, the anodic polarization curves and the open circuit potential – time monitoring for corrosion behavior evaluation and optical microscopy for the structure analysis. The tarnish tendency of alloys was estimated using the method of cyclic immersion with frequency of 10 seconds for each minute during 72 hours in Na2S containing solution. The most important conclusion is that the alloys are comparable from corrosion and tarnish point of view, but we recommend to use the nickel base alloy only for orthodontic devices implanted for short periods of time, because of higher quantity of released ions.

  13. Radionuclide trap

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1978-01-01

    The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition

  14. Radionuclide sorption behavior in particulate matter in near coastal marine environments

    International Nuclear Information System (INIS)

    Hansen, A.M.; Ortega-Lara, V.; Leckie, J.O.

    1997-01-01

    Full text: In order to evaluate the migration behavior of radioactive cesium and strontium while transported from continental aquatic systems to marine environments, the sorption behaviors for these metals were evaluated in several different environments. Laboratory experiments using radioactive tracers, and equilibrium as well as time dependent modeling were used to evaluate and quantify the distribution of the two elements as a function of element chemistry, solid substrate characteristics and solution composition. The experimental conditions reflected salinities ranging from those found in rivers and lakes through estuaries to the ocean. Adsorption constants were obtained for strontium in natural sediments from these aquatic environments. The strontium specification was evaluated in solution as well as in the adsorbed state. Sorption of strontium occurred mainly as outer sphere complexes. Major cations, ligands (soluble and particulate), ionic strength, and pH were among parameters that affected the distribution of cesium and strontium between adsorbed and dissolved forms. Time-dependent sorption behaviors were observed under study dissolved salt and suspended sediment conditions. Desorption occurred to some degree for all sediment types. Cesium was exchanged with potassium and sodium in clay minerals and was therefore less desorbed than would be expected. The results allowed the description of migration behaviors of two important pollutants from the atomic energy industry

  15. A three-dimensional stochastic model of the behavior of radionuclides in forests. Part 2. Cs-137 behavior in forest soils

    International Nuclear Information System (INIS)

    Berg, Mitchell T.; Shuman, Larry J.

    1995-01-01

    Using a three-dimensional stochastic model of radionuclides in forests developed in Part 1, this work simulates the long-term behavior of Cs-137 in forest soil. It is assumed that the behavior of Cs-137 in soils is driven by its advection and dispersion due to the infiltration of the soil solution, and its sorption to the soil matrix. As Cs-137 transport through soils is affected by its uptake and release by forest vegetation, a model of radiocesium behavior in forest vegetation is presented in Part 3 of this paper. To estimate the rate of infiltration of water through the soil, models are presented to estimate the hydrological cycle of the forest including infiltration, evapotranspiration, and the root uptake of water. The state transition probabilities for the random walk model of Cs-137 transport are then estimated using the models developed to predict the distribution of water in the forest. The random walk model is then tested using a base line scenario in which Cs-137 is deposited into a coniferous forest ecosystem

  16. Oceanic conditions and their variations affecting behavior of radionuclides in marine environment off Aomori prefecture

    International Nuclear Information System (INIS)

    Shima, Shigeki

    2009-01-01

    In order to elucidate the behavior of radioactive nuclides liberated from the Rokkasho reprocessing plant into the ocean, the characteristics of oceanic region around this plant were clarified by the measurements of oceanic circulation, flow rate and its seasonal variation. Further the computer simulation model for the reconstruction and prediction of oceanic conditions off Rokkasho was prepared. The whole image on this oceanic region was therefore reconstructed using this model. (M.H.)

  17. Prediction of hot deformation behavior of high phosphorus steel using artificial neural network

    Science.gov (United States)

    Singh, Kanchan; Rajput, S. K.; Soota, T.; Verma, Vijay; Singh, Dharmendra

    2018-03-01

    To predict the hot deformation behavior of high phosphorus steel, the hot compression experiments were performed with the help of thermo-mechanical simulator Gleeble® 3800 in the temperatures ranging from 750 °C to 1050 °C and strain rates of 0.001 s-1, 0.01 s-1, 0.1 s-1, 0.5 s-1, 1.0 s-1 and 10 s-1. The experimental stress-strain data are employed to develop artificial neural network (ANN) model and their predictability. Using different combination of temperature, strain and strain rate as a input parameter and obtained experimental stress as a target, a multi-layer ANN model based on feed-forward back-propagation algorithm is trained, to predict the flow stress for a given processing condition. The relative error between predicted and experimental stress are in the range of ±3.5%, whereas the correlation coefficient (R2) of training and testing data are 0.99986 and 0.99999 respectively. This shows that a well-trained ANN model has excellent capability to predict the hot deformation behavior of materials. Comparative study shows quite good agreement of predicted and experimental values.

  18. Radionuclides deposition over Antarctica

    International Nuclear Information System (INIS)

    Pourchet, M.; Magand, O.; Frezzotti, M.; Ekaykin, A.; Winther, J.-G.

    2003-01-01

    A detailed and comprehensive map of the distribution patterns for both natural and artificial radionuclides over Antarctica has been established. This work integrates the results of several decades of international programs focusing on the analysis of natural and artificial radionuclides in snow and ice cores from this polar region. The mean value (37±20 Bq m -2 ) of 241 Pu total deposition over 28 stations is determined from the gamma emissions of its daughter 241 Am, presenting a long half-life (432.7 yrs). Detailed profiles and distributions of 241 Pu in ice cores make it possible to clearly distinguish between the atmospheric thermonuclear tests of the fifties and sixties. Strong relationships are also found between radionuclide data ( 137 Cs with respect to 241 Pu and 210 Pb with respect to 137 Cs), make it possible to estimate the total deposition or natural fluxes of these radionuclides. Total deposition of 137 Cs over Antarctica is estimated at 760 TBq, based on results from the 90-180 deg. East sector. Given the irregular distribution of sampling sites, more ice cores and snow samples must be analyzed in other sectors of Antarctica to check the validity of this figure

  19. A simple artificial life model explains irrational behavior in human decision-making.

    Directory of Open Access Journals (Sweden)

    Carolina Feher da Silva

    Full Text Available Although praised for their rationality, humans often make poor decisions, even in simple situations. In the repeated binary choice experiment, an individual has to choose repeatedly between the same two alternatives, where a reward is assigned to one of them with fixed probability. The optimal strategy is to perseverate with choosing the alternative with the best expected return. Whereas many species perseverate, humans tend to match the frequencies of their choices to the frequencies of the alternatives, a sub-optimal strategy known as probability matching. Our goal was to find the primary cognitive constraints under which a set of simple evolutionary rules can lead to such contrasting behaviors. We simulated the evolution of artificial populations, wherein the fitness of each animat (artificial animal depended on its ability to predict the next element of a sequence made up of a repeating binary string of varying size. When the string was short relative to the animats' neural capacity, they could learn it and correctly predict the next element of the sequence. When it was long, they could not learn it, turning to the next best option: to perseverate. Animats from the last generation then performed the task of predicting the next element of a non-periodical binary sequence. We found that, whereas animats with smaller neural capacity kept perseverating with the best alternative as before, animats with larger neural capacity, which had previously been able to learn the pattern of repeating strings, adopted probability matching, being outperformed by the perseverating animats. Our results demonstrate how the ability to make predictions in an environment endowed with regular patterns may lead to probability matching under less structured conditions. They point to probability matching as a likely by-product of adaptive cognitive strategies that were crucial in human evolution, but may lead to sub-optimal performances in other environments.

  20. A simple artificial life model explains irrational behavior in human decision-making.

    Science.gov (United States)

    Feher da Silva, Carolina; Baldo, Marcus Vinícius Chrysóstomo

    2012-01-01

    Although praised for their rationality, humans often make poor decisions, even in simple situations. In the repeated binary choice experiment, an individual has to choose repeatedly between the same two alternatives, where a reward is assigned to one of them with fixed probability. The optimal strategy is to perseverate with choosing the alternative with the best expected return. Whereas many species perseverate, humans tend to match the frequencies of their choices to the frequencies of the alternatives, a sub-optimal strategy known as probability matching. Our goal was to find the primary cognitive constraints under which a set of simple evolutionary rules can lead to such contrasting behaviors. We simulated the evolution of artificial populations, wherein the fitness of each animat (artificial animal) depended on its ability to predict the next element of a sequence made up of a repeating binary string of varying size. When the string was short relative to the animats' neural capacity, they could learn it and correctly predict the next element of the sequence. When it was long, they could not learn it, turning to the next best option: to perseverate. Animats from the last generation then performed the task of predicting the next element of a non-periodical binary sequence. We found that, whereas animats with smaller neural capacity kept perseverating with the best alternative as before, animats with larger neural capacity, which had previously been able to learn the pattern of repeating strings, adopted probability matching, being outperformed by the perseverating animats. Our results demonstrate how the ability to make predictions in an environment endowed with regular patterns may lead to probability matching under less structured conditions. They point to probability matching as a likely by-product of adaptive cognitive strategies that were crucial in human evolution, but may lead to sub-optimal performances in other environments.

  1. Behavior of a PCM at Varying Heating Rates: Experimental and Theoretical Study with an Aim at Temperature Moderation in Radionuclide Concrete Encasements

    Science.gov (United States)

    Medved', Igor; Trník, Anton

    2018-07-01

    Phase-change materials (PCMs) can store/release thermal energy within a small temperature range. This is of interest in various industrial applications, for example, in civil engineering (heating/cooling of buildings) or cold storage applications. Another application may be the moderation of temperature increases in concrete encasements of radionuclides during their decay. The phase-change behavior of a material is determined by its heat capacity and the peak it exhibits near a phase change. We analyze the behavior of such peaks for a selected PCM at heating rates varying between 0.1°C\\cdot min^{-1} and 1°C\\cdot min^{-1}, corresponding in real situations to different decay rates of radionuclides. We show that experimentally measured peaks can be plausibly described by an equilibrium theory that enables us to calculate the latent heat and phase-change temperature from experimental data.

  2. Artificial modulation of the gating behavior of a K+ channel in a KvAP-DNA chimera.

    Directory of Open Access Journals (Sweden)

    Andrew Wang

    Full Text Available We present experiments where the gating behavior of a voltage-gated ion channel is modulated by artificial ligand binding. We construct a channel-DNA chimera with the KvAP potassium channel reconstituted in an artificial membrane. The channel is functional and the single channel ion conductivity unperturbed by the presence of the DNA. However, the channel opening probability vs. bias voltage, i.e., the gating, can be shifted considerably by the electrostatic force between the charges on the DNA and the voltage sensing domain of the protein. Different hybridization states of the chimera DNA thus lead to different response curves of the channel.

  3. Environmental behavior of the radionuclides released from the Fukushima Daiichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    Yamazaki, Hideo

    2014-01-01

    The environmental behavior of radioactive nuclides released from the Fukushima Daiichi Nuclear Power Station (FDNPS) accident in eastern Japan was investigated. The radioactive pollution of environmental samples, including airborne dust, soil, sediment, fish, and other organisms was described. It was evaluated for environmental behavior and fate of the radioactive material from the spatial and temporal distribution of the radioactive nuclides. In Higashiosaka City about 600 km away from FDNPS, it begins to detect the radioactive nuclides in the airborne dust from 25th March 2011. Radioactive fission products 95 Zr- 95 Nb was detected on 18th April. The concentrations of 131 I, 134 Cs, and 137 Cs in the soil collected from Fukushima City were 126000, 14000, and 14200 Bq/kg on 19th March 2011 and 12800, 13200, and 13700 Bq/kg on 26th March 2011, respectively. The concentrations of 131 I, 134 Cs, and 137 Cs in the soil samples collected from March-June 2011 from study sites in metropolitan area and Kanto region ranged from nd to 91900, 59 to 16100, and 69 to 17600 Bq/kg, respectively. (Concentrations of 131 I were done decay correction to the value of 16th March) Radioactivities in fish samples collected from off FDNPS, Tokyo Bay, and Kejonuma Pond were measured. The radioactive contamination of forest ecosystem was also investigated. Two processes are involved in the radioactive contamination of the environment from the FDNPS accident. One is contamination by radioactive nuclides released from the hydrogen explosion. Leakage of contaminated cooling water to the ocean is in other important environmental pollution. We must continue carefully monitoring of radioactive nuclides in the environment. (author)

  4. Investigation of solution chemistry effects on sorption behavior of radionuclide 64Cu(II) on illite

    International Nuclear Information System (INIS)

    Shitong Yang; Guodong Sheng; Zhiqiang Guo; Yubing Sun; Donglin Zhao

    2011-01-01

    In this work, a series of batch experiments were carried out to investigate the effect of various environmental factors such as contact time, pH, ionic strength, coexisting electrolyte ions, humic substances and temperature on the sorption behavior of illite towards 64 Cu(II). The results indicated that 64 Cu(II) sorption on illite achieved equilibrium quickly. The pH- and ionic strength-dependent sorption suggested that 64 Cu(II) sorption on illite was dominated by ion exchange or outer-sphere surface complexation at pH 7. A positive effect of humic substances on 64 Cu(II) sorption was found at pH 6.5. The Langmuir and Freundlich models were used to simulate the sorption isotherms of 64 Cu(II) at three different temperatures of 293, 313, and 333 K. The thermodynamic parameters (ΔH 0 , ΔS 0 , and ΔG 0 ) of 64 Cu(II) sorption on illite were calculated from the temperature dependent sorption isotherms, and the results indicated that the sorption of 64 Cu(II) on illite was endothermic and spontaneous. From the experimental results, it is possible to conclude that illite has good potentialities for cost-effective treatments of 64 Cu(II)-contaminated wastewaters. (author)

  5. Retention behavior of flavonoids on immobilized artificial membrane chromatography and correlation with cell-based permeability.

    Science.gov (United States)

    Tsopelas, Fotios; Tsagkrasouli, Maria; Poursanidis, Pavlos; Pitsaki, Maria; Vasios, George; Danias, Panagiotis; Panderi, Irene; Tsantili-Kakoulidou, Anna; Giaginis, Constantinos

    2018-03-01

    The aim of the study was to investigate the immobilized artificial membrane (IAM) retention mechanism for a set of flavonoids and to evaluate the potential of IAM chromatography to model Caco-2 permeability. For this purpose, the retention behavior of 41 flavonoid analogs on two IAM stationary phases, IAM.PC.MG and IAM.PC.DD2, was investigated. Correlations between retention factors, logk w(IAM) and octanol-water partitioning (logP) were established and the role of hydroxyl groups of flavonoids to the underlying retention mechanism was explored. IAM retention and logP values were used to establish sound linear models with Caco-2 permeability (logP app ) taken from the literature. Both stepwise regression and multivariate analysis confirmed the contribution of hydrogen bond descriptors, as additional parameters in the either logk w(IAM) or logP models. Retention factors on both IAM stationary phases showed comparable performance with n-octanol-water partitioning towards Caco-2 permeability. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Patient behavior and the benefits of artificial intelligence: the perils of "dangerous" literacy and illusory patient empowerment.

    Science.gov (United States)

    Schulz, Peter J; Nakamoto, Kent

    2013-08-01

    Artificial intelligence can provide important support of patient health. However, limits to realized benefits can arise as patients assume an active role in their health decisions. Distinguishing the concepts of health literacy and patient empowerment, we analyze conditions that bias patient use of the Internet and limit access to and impact of artificial intelligence. Improving health literacy in the face of the Internet requires significant guidance. Patients must be directed toward the appropriate tools and also provided with key background knowledge enabling them to use the tools and capitalize on the artificial intelligence technology. Benefits of tools employing artificial intelligence to promote health cannot be realized without recognizing and addressing the patients' desires, expectations, and limitations that impact their Internet behavior. In order to benefit from artificial intelligence, patients need a substantial level of background knowledge and skill in information use-i.e., health literacy. It is critical that health professionals respond to patient search for information on the Internet, first by guiding their search to relevant, authoritative, and responsive sources, and second by educating patients about how to interpret the information they are likely to encounter. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Artificial radionuclides 90Sr and 241Am in the sediments of the Baltic Sea: Total and spatial inventories and some temporal trends

    International Nuclear Information System (INIS)

    Hutri, Kaisa-Leena; Mattila, Jukka; Ikäheimonen, Tarja Tuulikki; Vartti, Vesa-Pekka

    2013-01-01

    Highlights: • The inventories of 137 Sr and 241 Am in the Baltic Sea is studied. • About 20 sediment cores around the Baltic Sea were analyzed. • The results show that 90 Sr distribution is uneven and effected by the Chernobyl fallout. • 241 Am is more evenly distributed in the sediments. • The Baltic Sea is the most contaminated sea with respect to 137 Cs in sediments. -- Abstract: The Baltic Sea was contaminated by radioactivity following global nuclear fallout and later by the Chernobyl accident. Despite the decrease of radioactivity caused by radioactive decay, radionuclides have a prolonged residence time in the water of the Baltic Sea due to slow water exchange and relatively rapid sedimentation. Very little is known about the amounts or spatial differences of 90 Sr and 241 Am in the Baltic Sea sediments. In this study, 20 sediment cores taken around the Baltic Sea were investigated to estimate inventories of these radionuclides. The rough results show that the Chernobyl fallout added the amount of 90 Sr in the same areas where the increase of 137 Cs can be detected, whereas this is not the case for 241 Am which is more evenly distributed in the sea bottom. In addition, local differences occur in the concentrations. These results are an important amendment to the radioactivity baseline of the Baltic Sea

  8. Development and application of an on-line sequential injection system for the separation of artificial and natural radionuclides in environmental samples

    International Nuclear Information System (INIS)

    Kim, C.-K.; Sansone, U.; Martin, P.; Kim, C.-S.

    2007-02-01

    The Chemistry Unit of the Physics, Chemistry and Instrumentation Laboratory in the IAEA's Seibersdorf Laboratory in Austria, has the programmatic responsibility to provide assistance to Member State laboratories in maintaining and improving the reliability of analytical measurement results, both in trace element and radionuclide determinations. This is accomplished through the provision of reference materials of terrestrial origin, validated analytical procedures, training in the implementation of internal quality control, and through the evaluation of measurement performance by organization of worldwide and regional interlaboratory comparison exercises. In this framework an on-line sequential injection (SI) system was developed, which can be widely used for the separation and preconcentration of target analytes from diverse environmental samples. The system enables the separation time to be shortened by maintaining a constant flow rate of solution and by avoiding clogging or bubbling in a chromatographic column. The SI system was successfully applied to the separation of Pu in IAEA reference material (IAEA Soil-6) and to the sequential separation of 210 Po and 210 Pb in phosphogypsum candidate reference material. The replicate analysis results of Pu in IAEA reference material (Soil-6) obtained with the SI system are in good agreement with the recommended value within 5% of standard deviation. The SI system enabled a halving in the separation time required for of radionuclides

  9. Radionuclide cisternography

    International Nuclear Information System (INIS)

    Song, H.H.

    1980-01-01

    The purpose of this thesis is to show that radionuclide cisternography makes an essential contribution to the investigation of cerebrospinal fluid (CSF) dynamics, especially for the investigation of hydrocephalus. The technical details of radionuclide cisternography are discussed, followed by a description of the normal and abnormal radionuclide cisternograms. The dynamics of CFS by means of radionuclide cisternography were examined in 188 patients in whom some kind of hydrocephalus was suspected. This study included findings of anomalies associated with hydrocephalus in a number of cases, such as nasal liquorrhea, hygromas, leptomeningeal or porencephalic cysts. The investigation substantiates the value of radionuclide cisternography in the diagnosis of disturbances of CSF flow. The retrograde flow of radiopharmaceutical into the ventricular system (ventricular reflux) is an abnormal phenomenon indicating the presence of communicating hydrocephalus. (Auth.)

  10. State of contamination of French food produces by artificial radionuclides; Etat de la contamination par les radionucleides artificiels des produits alimentaires francais

    Energy Technology Data Exchange (ETDEWEB)

    Boursier, B.; Guiard, A.; Tesolin, B.; Janin, F. [Centre National d`Etudes Veterinaires et Alimentaires, 75 - Paris (France)

    1994-05-01

    This study presents the results of 40236 recorded levels of caesium {sup 134}Cs and {sup 137}Cs activities carried out on French food. These controls, performed through gamma-spectrometry, have been carried out in France by the Veterinary Services and the CNEVA-LCHA (Centre National d`Etudes Veterinaires - Laboratoire Central d`Hygiene Alimentaire), as part of a radionuclides survey after the Chernobyl accident. The results have been collected by the CNEVA-LCHA, and show in 1992 that 99.6% of the radioactivity levels in the French food are below 50 Bq/kg. The present situation seems to be satisfying. However, very small amounts of {sup 137}Cs residues were noticed in some mushroom species, such as Cantharellus tubaeformis. (authors). 3 figs., 1 tab.

  11. A Review on Artificial Aging Behaviors of Fiber Reinforced Polymer-matrix Composites

    OpenAIRE

    Meng Jiangyan; Wang Yunying

    2016-01-01

    As is known, factors in climate environment such as hygrothermal effect and UV may have a negative effect on the mechanical properties of fiber reinforced polymer-matrix composites, resulting in their strength and stiffness degraded. In this review, we summarize all the recent studies on the artificial climate aging, hygrothermal aging, and thermal-oxidation aging of fiber reinforced polymer-matrix composites, as well as their artificial accelerated aging and natural aging. In addition, studi...

  12. Thermal behavior studies in building using artificial neural network for non air conditioned terrace house in Malaysia

    International Nuclear Information System (INIS)

    Zainazlan Md Zain; Mohd Nasir Taib; Shahrizam Mohd Shah Baki

    2006-01-01

    Strategies to improve energy efficiency in buildings have continuously being improved and becoming more effective as new knowledge on the building behavior and technology continue to develop. Nevertheless, effort to explore for further improvement must continuously undertake to seek more energy efficient and cost effective systems. Artificial Neural Network (ANN) is currently one of the most popular mechanisms to forecast any form of behavior and phenomena. Building thermal behavior can be studied and potential for energy utilization improvement without compromising thermal comfort can be explored using ANN. This paper explores the possibility of monitoring, predicting and forecasting the thermal behavior inside a building space and the optimization of building design. Typical result of experimental data and simulated data is presented. The sample house used adopted various thermal comfort strategies like cross ventilation and space air flow consideration

  13. Radionuclide carrier

    International Nuclear Information System (INIS)

    Hartman, F.A.; Kretschmar, H.C.; Tofe, A.J.

    1978-01-01

    A physiologically acceptable particulate radionuclide carrier is described. It comprises a modified anionic starch derivative with 0.1% to 1.5% by weight of a reducing agent and 1 to 20% by weight of anionic substituents

  14. Estimation of the behaviour of artificial environmental radionuclides and the resulting population exposure in the vicinity of nuclear facilities, with particular regard to the ingestion of agricultural products

    International Nuclear Information System (INIS)

    Teufel, D.

    1977-12-01

    To begin with, the method recommended by the Radiation Protection Commission for the calculation of ingested doses was analyzed, and the factors influencing the calculation were reviewed in the relevant literature. The main points of emphasis were the transfer factors. For all radionuclides contained in the model emission mixtures, calculation factors were compared with the results of enrichment experiments in the relevant literature. It was found that calculation factors were always either among the lowest transport factors given in the literature or even several orders of magnitude smaller than realistic experimental factors. In the experimental part, transfer factors were determined for the three elements Co, Mn, and Sr in various plants and soils. In most cases, these values were higher than those recommended by the Gesellschaft fuer Reaktorsicherheit and the Radiation Protection Commission. Radiation doses due to ingestion of various foodstuffs in the vicinity of a modern nuclear power plant (1300 MW PWR) were calculated in a model program. The radiation burden was calculated separately for adults and infants for various organs. Contrary to the experts' opinions by the Technische Ueberwachungsvereine and the Gesellschaft fuer Reaktorsicherheit usually presented in the licensing procedure, values significantly higher than the maximum permissible radiation exposure were found in many cases. It seems that radiation exposure is heightened by a number of factors which due to a lack of data, cannot be included in the computer program (e.g. effects of inversion conditions, atmospheric conditions of low wind force, cooling towers, etc.) (orig./MG) [de

  15. Geomorphological applications of environmental radionuclides

    International Nuclear Information System (INIS)

    Quine, T.A.; Walling, D.

    1998-01-01

    Geomorphologists have shown increasing interest in environmental radionuclides since pioneering studies by Ritchie and McHenry in the USA and Campbell, Longmore and Loughran in Australia. Environmental radionuclides have attracted this interest because they provide geomorphologists with the means to trace sediment movement within the landscape. They, therefore, facilitate investigation of subjects at the core of geomorphology, namely the rates and patterns of landscape change. Most attention has been focussed on the artificial radionuclide caesium-137 ( 137 Cs) but more recently potential applications of the natural radionuclides lead-210 ( 210 Pb) and beryllium-7( 7 Be) have been investigated (Walling et al., 1995; Wallbrink and Murray, 1996a, 1996b). The origin, characteristics and applications of these radionuclides are summarised. These radionuclides are of value as sediment tracers because of three important characteristics: a strong affinity for sediment; a global distribution and the possibility of measurement at low concentration. Geomorphological applications of environmental radionuclides provide unique access to detailed qualitative data concerning landscape change over a range of timescales

  16. Electrochemical behavior and pH stability of artificial salivas for corrosion tests.

    Science.gov (United States)

    Queiroz, Gláucia Maria Oliveira de; Silva, Leandro Freitas; Ferreira, José Tarcísio Lima; Gomes, José Antônio da Cunha P; Sathler, Lúcio

    2007-01-01

    It is assumed that the compositions of artificial salivas are similar to that of human saliva. However, the use of solutions with different compositions in in vitro corrosion studies can lead dissimilar electrolytes to exhibit dissimilar corrosivity and electrochemical stability. This study evaluated four artificial salivas as regards pH stability with time, redox potentials and the polarization response of an inert platinum electrode. The tested solutions were: SAGF medium, Mondelli artificial saliva, UFRJ artificial saliva (prepared at the School of Pharmacy, Federal University of Rio de Janeiro, RJ, Brazil) and USP-RP artificial saliva (prepared at the School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, SP, Brazil). It was observed that pH variations were less than 1 unit during a 50-hour test. The SAGF medium, and the UFRJ and USP-RP solutions exhibited more oxidizing characteristics, whereas the Mondelli solution presented reducing properties. Anodic polarization revealed oxidation of the evaluated electrolytes at potentials below +600 mV SCE. It was observed that the UFRJ and USP-RP solutions presented more intense oxidation and reduction processes as compared to the Mondelli and SAGF solutions.

  17. The use of artificial crabs for testing predatory behavior and health in the octopus.

    Science.gov (United States)

    Amodio, Piero; Andrews, Paul; Salemme, Marinella; Ponte, Giovanna; Fiorito, Graziano

    2014-01-01

    The willingness of the cephalopod mollusc Octopus vulgaris to attack a live crab is traditionally used as a method to assess the overall health and welfare of octopuses in the laboratory. This method requires placing a crab in the home tank of an animal, measuring the time (latency) taken for the octopus to initiate an attack and withdrawing the crab immediately prior to capture. The same crab is commonly used to assess multiple octopuses as part of daily welfare assessment. Growing concern for the welfare of crustaceans and a review of all laboratory practices for the care and welfare of cephalopods following the inclusion of this taxon in 2010/63/EU prompted a study of the utility of an artificial crab to replace a live crab in the assessment of octopus health. On consecutive days O. vulgaris (N=21) were presented with a live, a dead or an artificial crab, and the latency to attack measured. Despite differences in the predatory performance towards the three different crab alternatives, octopuses readily attacked the artificial (and the dead) crab, showing that they can generalize and respond appropriately towards artificial prey. Researchers should consider using an artificial crab to replace the use of a live crab as part of the routine health assessment of O. vulgaris.

  18. Radionuclides in food

    International Nuclear Information System (INIS)

    Fernandez Gomez, Isis Maria

    2008-01-01

    The sources of the presence of radionuclides in food are presented: natural radiation and artificial radiation. The transfer of radionuclides through food chains, intakes of radionuclides to the body with its partners effective doses and typical consumption of basic foods of a rural adult population are exposed as main topics. Also the radiation doses from natural sources and exposure to man by ingestion of contaminated food with radionuclides of artificial origin are shown. The contribution of the food ingestion to the man exposure depends on: characteristics of radionuclide, natural conditions, farming practices and eating habits of the population. The principal international organizations in charge of setting guide levels for radionuclides in food are mentioned: standards, rules and the monitoring. It establishes that a guide is necessary for the food monitoring; the alone CODEX ALIMENTARIUS is applicable to emergency situations and the generic action levels proposed by the CODEX not satisfy all needs (no guiding international levels for planned or existing situations such as NORM). There are handled mainly socio-economic and political aspects. Among the actions to be taken are: to assure a public comprehensive information over the risk evaluation in food; to reinforce the collaboration among the different international organizations (WHO, IAEA, ICRP, EC) in relation with the food of set; to give follow-up to the control of the drinkable water and NORM's presence in the food. In addition, it is possible to create the necessary mechanisms to reduce the number of irrelevant measures and bureaucratic useless steps (certificates); to promote the exchange between the different institutions involved in the topic of the food, with relation to the acquired experiences and learned lessons. Likewise, it might examine the possibility of a multidisciplinary approximation (radioactive and not radioactive pollutants); to elaborate a technical guide to assure the

  19. Behavior and environmental impacts of radionuclides during the hydrometallurgy of calcareous and argillaceous rocks, southwestern Sinai, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    El Aassy, Ibrahim E. [Nuclear Materials Authority (Egypt); Nada, Afaf A., E-mail: afafhero_nada@yahoo.com [Faculty of Women for Arts, Science and Education (Egypt); El Galy, Mohamed M.; El Feky, Mohamed G. [Nuclear Materials Authority (Egypt); Abd El Maksoud, Thanaa M.; Talaat, Shadia M. [Faculty of Women for Arts, Science and Education (Egypt); Ibrahim, Eman M. [Nuclear Materials Authority (Egypt)

    2012-06-15

    The hydrometallurgy of radionuclides means getting the radioelements from the rocks into solution by leaching, getting the radionuclides from the solution by extraction process, and then precipitation of the desired elements to obtain concentrate. The follow-up of the radionuclides during these processes is the main target of this work to identify the identity of the original samples, pregnant solutions (leachates), residuals and the concentrate. Six samples were chosen to achieve this work. The leaching process was carried out under the conditions; 20-30% acid (H{sub 2}SO{sub 4}) concentration, 1:3 solid/liquid ratios, 60 min stirring time at room temperature. The activity concentrations of {sup 238}U, {sup 235}U, {sup 234}U, {sup 226}Ra, {sup 214}Pb, {sup 214}Bi, {sup 232}Th and {sup 40}K were measured in the original samples, residuals and U-concentrate (Bq/kg), and leachates (Bq/ Script-Small-L). The results indicate that, the radionuclides before {sup 226}Ra in the {sup 238}U decay series are more leachable (released) than those from {sup 226}Ra to {sup 214}Bi in the order; {sup 234}U>{sup 238}U={sup 235}U Much-Greater-Than {sup 226}Ra>{sup 214}Pb>{sup 214}Bi. {sup 232}Th and {sup 40}K are immobile under the present conditions. The radiological hazards of natural radioactivity in the original samples, leachates, residuals and U-concentrate were calculated and compared with the internationally recommended values and were found to be much higher than the world average values. - Highlights: Black-Right-Pointing-Pointer Original rocks, leachates, residuals and concentrate were studied. Black-Right-Pointing-Pointer Radionuclides concentrations were examined through different phases. Black-Right-Pointing-Pointer Radionuclides are more leachable before than that after {sup 226}Ra series. Black-Right-Pointing-Pointer Radiological hazards were compared with the international values. Black-Right-Pointing-Pointer Cautions should be taken in considerations during mining

  20. Diffusion and Leaching Behavior of Radionuclides in Category 3 Waste Encasement Concrete and Soil Fill Material – Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Mattigod, Shas V.; Wellman, Dawn M.; Bovaird, Chase C.; Parker, Kent E.; Clayton, Libby N.; Powers, Laura; Recknagle, Kurtis P.; Wood, Marcus I.

    2011-08-31

    One of the methods being considered for safely disposing of Category 3 low-level radioactive wastes is to encase the waste in concrete. Such concrete encasement would contain and isolate the waste packages from the hydrologic environment and would act as an intrusion barrier. The current plan for waste isolation consists of stacking low-level waste packages on a trench floor, surrounding the stacks with reinforced steel, and encasing these packages in concrete. These concrete-encased waste stacks are expected to vary in size with maximum dimensions of 6.4 m long, 2.7 m wide, and 4 m high. The waste stacks are expected to have a surrounding minimum thickness of 15 cm of concrete encasement. These concrete-encased waste packages are expected to withstand environmental exposure (solar radiation, temperature variations, and precipitation) until an interim soil cover or permanent closure cover is installed, and to remain largely intact thereafter. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The mobilized radionuclides may escape from the encased concrete by mass flow and/or diffusion and move into the surrounding subsurface environment. Therefore, it is necessary to assess the performance of the concrete encasement structure and the ability of the surrounding soil to retard radionuclide migration. The retardation factors for radionuclides contained in the waste packages can be determined from measurements of diffusion coefficients for these contaminants through concrete and fill material. Some of the mobilization scenarios include (1) potential leaching of waste form before permanent closure cover is installed; (2) after the cover installation, long-term diffusion of radionuclides from concrete waste form into surrounding fill material; (3) diffusion of radionuclides from contaminated soils into adjoining concrete encasement and clean fill material. Additionally, the rate of

  1. Using an artificial agent as a behavior model to promote assistive technology acceptance

    NARCIS (Netherlands)

    Fountoukidou, Sofia; Ham, Jaap; Matzat, Uwe; Midden, Cees

    2018-01-01

    Despite technological advancements in assistive technologies, studies show high rates of non-use. Because of the rising numbers of people with disabilities, it is important to develop strategies to increase assistive technology acceptance. The current research investigated the use of an artificial

  2. Radionuclides in the study of marine processes

    International Nuclear Information System (INIS)

    Kershaw, P.J.; Woodhead, D.S.

    1991-01-01

    For many years, the radioactive properties of the naturally occurring radionuclides have been used to determine their distributions in the marine environment and, more generally, to gain an understanding of the dynamic processes which control their behaviour in attaining these distributions. More recently the inputs from human activities of both natural and artificial (i.e. man-made) radionuclides have provided additional opportunities for the study of marine processes on local, regional and global scales. The primary objective of the symposium is to provide a forum for an open discussion of the insights concerning processes in the marine environment which can be gained from studies of radionuclide behaviour. Papers have been grouped within the following principal themes; the uses of radionuclides as tracers of water transport; scavenging and particulate transport processes in the oceans as deduced from radionuclide behaviour; processes in the seabed and radionuclides in biological systems. (Author)

  3. Radionuclide generators

    International Nuclear Information System (INIS)

    Lambrecht, R.M.

    1983-01-01

    The status of radionuclide generators for chemical research and applications related to the life sciences and biomedical research are reviewed. Emphasis is placed upon convenient, efficient and rapid separation of short-lived daughter radionuclides in a chemical form suitable for use without further chemical manipulation. The focus is on the production of the parent, the radiochemistry associated with processing the parent and daughter, the selection and the characteristic separation methods, and yields. Quality control considerations are briefly noted. The scope of this review includes selected references to applications of radionuclide generators in radiopharmaceutical chemistry, and the life sciences, particularly in diagnostic and therapeutic medicine. The 99 Mo-sup(99m)Tc generator was excluded. 202 references are cited. (orig.)

  4. Transcuticular translocation of radionuclides on plant leaf surfaces

    International Nuclear Information System (INIS)

    Matsumoto, Ken-ichi; Watanabe, Tadakazu; Ambe, Shizuko; Yamaguchi, Isamu

    1996-01-01

    The cuticle covering all the outermost surfaces of the aerial parts of plants could play a selective role in uptake and translocation of radionuclides from air into plants. In this study, we investigated the transcuticular uptake and translocation behavior via water droplets of various radionuclides in red clover, orchard grass, Japanese radish and mung bean. Ten μl of an aqueous solution of the multitracer generated from Au was applied to the upper surface of the 2nd leaf of the plants at the 5th leaf stage. The plants were then grown for 14 days at 25degC and 70% RH under illumination of artificial solar lights. The transcuticular uptake and translocation throughout the plant were periodically assayed by determining the radioactivity in the surface residue, the cuticle layer beneath the applied site, the leaf area outside the applied site, the other aerial parts and the root of the plant, using an HPGe detector. The applied radionuclides were absorbed into, in turn, the cuticle layer beneath the applied site and then translocated through the cuticle to the inner tissue and eventually to the other aerial parts and finally to the roots, of the plant. The distribution and accumulation in the plant seems to depend upon the characteristics of each radionuclide and plant species. Ca * and Te * tended to remain on leaf surfaces without being absorbed into the cuticle. On the other hand, Sc * , Co * , Zn * , Se * , Rb * , and Eu * were easily absorbed and translocated to every part of the plant including the root. The other radionuclides such as Be * , Mn * , Sr * , Y * , Ba * , Ce * , Pm * , Gd * , Hf * , Yb * , Lu * , Os * , Ir * , and Pt * remained in the region close to the site of their application. The above results possibly indicate the existence of mechanisms common to these plants for selective transcuticular uptake and translocation of radionuclides within plant tissues, though their translocation was considerably influenced by the plant species. (author)

  5. Proficiency testing for radionuclides

    International Nuclear Information System (INIS)

    Faanhof, A.; Kotze, O.; Louw, I.

    2010-01-01

    Proficiency testing in general is only useful when it suites a certain purpose. With regards to radionuclides basically three fields of interest can be identified: (I)Foodstuffs-Introduced in the early 1960's to monitor the fall-out of nuclear tests and eventually the pathway to foodstuffs fit for human consumption. The demand for analysis increased substantially after the Chernobyl accident. (II) Natural radioactivity-Associated with mining and mineral processing of uranium and thorium baring mineral resources throughout the world where the radionuclides from the natural uranium and thorium decay series are found to pose concern for professional and public exposure. (III) Artificial radioactivity-This category covers mostly the long-lived nuclides generated by nuclear fission of the fuel used in nuclear power plants, research reactors and nuclear bomb tests. All three categories require a specific approach for laboratories to test their ability to analyze specific radio nuclides of interest in a variety of matrices. In this lecture I will give a compiled overview of the required radioanalytical skills, analysis sensitivity needed and radionuclides of interest, with more specific emphasis on QAQC of water sources and the recommended monitoring approach. And provide information on available reference materials and organizations/institutes that provide regular exercises for participating laboratories. I will also briefly communicate on the advantages and disadvantages of ISO/IEC 17025 accreditation for test laboratories, which is these days a prerequisite in national and international trade especially where foodstuffs and mineral products are concerned.

  6. Radionuclide generators

    International Nuclear Information System (INIS)

    Lambrecht, R.M.; Wollongong Univ.; Tomiyoshi, K.; Sekine, T.

    1997-01-01

    The present status and future directions of research and development on radionuclide generator technology are reported. The recent interest to develop double-neutron capture reactions for production of in vivo generators; neutron rich nuclides for radio-immunotherapeutic pharmaceuticals: and advances with ultra-short lived generators is highlighted. Emphasis is focused on: production of the parent radionuclide; the selection and the evaluation of support materials and eluents with respect to the resultant radiochemical yield of the daughter, and the breakthrough of the radionuclide parent: and, the uses of radionuclide generators in radiopharmaceutical chemistry, biomedical and industrial applications. The 62 Zn → 62 Cu, 66 Ni → 66 Cu, 103m Rh → 103 Rh, 188 W → 188 Re and the 225 Ac → 221 Fr → 213 Bi generators are predicted to be emphasized for future development. Coverage of the 99 Mo → 99m Tc generator was excluded, as it the subject of another review. The literature search ended June, 1996. (orig.)

  7. Radionuclide scanning

    International Nuclear Information System (INIS)

    Shapiro, B.

    1986-01-01

    Radionuclide scanning is the production of images of normal and diseased tissues and organs by means of the gamma-ray emissions from radiopharmaceutical agents having specific distributions in the body. The gamma rays are detected at the body surface by a variety of instruments that convert the invisible rays into visible patterns representing the distribution of the radionuclide in the body. The patterns, or images, obtained can be interpreted to provide or to aid diagnoses, to follow the course of disease, and to monitor the management of various illnesses. Scanning is a sensitive technique, but its specificity may be low when interpreted alone. To be used most successfully, radionuclide scanning must be interpreted in conjunction with other techniques, such as bone radiographs with bone scans, chest radiographs with lung scans, and ultrasonic studies with thyroid scans. Interpretation is also enhanced by providing pertinent clinical information because the distribution of radiopharmaceutical agents can be altered by drugs and by various procedures besides physiologic and pathologic conditions. Discussion of the patient with the radionuclide scanning specialist prior to the study and review of the results with that specialist after the study are beneficial

  8. Are voluntary wheel running and open-field behavior correlated in mice? Different answers from comparative and artificial selection approaches.

    Science.gov (United States)

    Careau, Vincent; Bininda-Emonds, Olaf R P; Ordonez, Genesis; Garland, Theodore

    2012-09-01

    Voluntary wheel running and open-field behavior are probably the two most widely used measures of locomotion in laboratory rodents. We tested whether these two behaviors are correlated in mice using two approaches: the phylogenetic comparative method using inbred strains of mice and an ongoing artificial selection experiment on voluntary wheel running. After taking into account the measurement error and phylogenetic relationships among inbred strains, we obtained a significant positive correlation between distance run on wheels and distance moved in the open-field for both sexes. Thigmotaxis was negatively correlated with distance run on wheels in females but not in males. By contrast, mice from four replicate lines bred for high wheel running did not differ in either distance covered or thigmotaxis in the open field as compared with mice from four non-selected control lines. Overall, results obtained in the selection experiment were generally opposite to those observed among inbred strains. Possible reasons for this discrepancy are discussed.

  9. Comparative study on the corrosion behavior of Ti-Nb and TMA alloys for dental application in various artificial solutions

    International Nuclear Information System (INIS)

    Bai, Y.J.; Wang, Y.B.; Cheng, Y.; Deng, F.; Zheng, Y.F.; Wei, S.C.

    2011-01-01

    The corrosion behavior of Ti-Nb dental alloy in artificial saliva with and without the addition of lactic acid and sodium fluoride was investigated by electrochemical techniques, with the commercial Titanium-molybdenum alloy (TMA) as a comparison. The chemical composition, microstructure and constitutional phase were characterized via energy dispersive spectrometry, optical microscope and X-ray diffraction, meanwhile the open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization measurements were carried out to study the corrosion resistance of experimental alloys, with the corroded surface being further characterized by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that the corrosion behavior of Ti-Nb alloy was similar to those TMA alloy samples in both artificial and acidified saliva solutions, whereas statistical analysis of the electrochemical impedance spectroscopy and polarization parameters showed Ti-Nb alloy exhibited better corrosion resistance in fluoridated saliva and fluoridated acidified saliva. SEM observation indicated that TMA alloy corroded heavily than Ti-Nb alloy in fluoride containing saliva. XPS surface analysis suggested that Nb 2 O 5 played an important role in anti-corrosion from the attack of fluoride ion. Based on the above finding, Ti-Nb alloy is believed to be suitable for the usage in certain fluoride treated dental works with excellent corrosion resistance in fluoride-containing oral media.

  10. Interactions of low-level, liquid radioactive wastes with soils. 1. Behavior of radionuclides in soil-waste systems

    International Nuclear Information System (INIS)

    Fowler, E.B.; Essington, E.H.; Polzer, W.L.

    1981-01-01

    The characteristics of radioactive wastes and soils vary over a wide range. Liquid radioactive waste entering the environment will eventually contact the soil or geological matrix; interactions will be determined by the chemical and physical nature of the liquid, as well as the soil matrix. We report here the results from an investigation of certain of those characteristics as they relate to retention of radionuclides by soils. Three fractions were demonstrated in the waste as filterable, soluble-sorbable, and soluble-nonsorbable; the physical nature of each fraction was demonstrated using autoradiographic techniques. Isotopes of plutonium and uranium and americium-241 in the soluble fraction of the waste were shown to have a negative charge as determined by ion exchange techniques. In the soil-waste systems, the net charge for those radionuclides was shown to change from predominantly negative to predominantly positive. Nevertheless, cesium-137 was shown to be predominantly positited by TVA and approved by NRC (formerly AEC) since June 1973. This report is based upon the revisions, approved through the end of this reporting period

  11. Radionuclide fate and effects

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The studies reported here deal with the full range of contaminant behavior and fate, from the initial physicochemical factors that govern radionuclide availability in terrestrial and aquatic environments to studies of contaminant transport by biological means. By design, we focus more on the biologically and chemically mediated transport processes and food-chain pathways than on the purely physical forms of contaminant transport, such as transport by wind and water

  12. Radionuclide transport processes in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Whicker, F.W.

    1983-01-01

    Some major principles and the status of knowledge concerning the transport of radionuclides through terrestrial ecosystems are reviewed. Fundamental processes which control the flow of radionuclides between ecosystem components such as air, soil, plants, and animals are described, with emphasis on deposition, resuspension, plant uptake, ingestion, and assimilation. Properties of radionuclides, organisms, and ecosystems are examined in relation to their influence on the accumulation of radioactive materials by plants and animals. The effects of the physicochemical nature of the radionuclide; morphology, physiology, and behavior of the organism; and soil, nutrient, and trophic characteristics of the ecosystem are highlighted. Observations in natural ecosystems on radionuclides such as 137 Cs, 90 Sr, 131 I, 3 H, and 239 Pu are used to illustrate current concepts. An assessment of the degree to which the processes controlling radionuclide behavior are understood and of our ability to simulate and predict such behavior with computerized models is offered. Finally, brief comments are made on research needs

  13. Anthropogenic radionuclides in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Q; Weng, J; Wang, J

    2007-11-15

    Studies of radionuclides in the environment have entered a new era with the renaissance of nuclear energy and associated fuel reprocessing, geological disposal of high-level nuclear wastes, and concerns about national security with respect to nuclear non-proliferation. This work presents an overview of anthropogenic radionuclide contamination in the environment, as well as the salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current development that contribute to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) commercial fuel reprocessing; (5) geological repository of high-level nuclear wastes, and (6) nuclear accidents. Then, we summarize the geochemical behavior for radionuclides {sup 99}Tc, {sup 129}I, and {sup 237}Np, because of their complex geochemical behavior, long half-lives, and presumably high mobility in the environment. Biogeochemical cycling and environment risk assessment must take into account speciation of these redox-sensitive radionuclides.

  14. Radionuclide examinations

    International Nuclear Information System (INIS)

    Lentle, B.C.

    1989-01-01

    This paper reports on radionuclide examinations of the pancreas. The pancreas, situated retroperitonally high in the epigastrium, was a particularly difficult organ to image noninvasively before ultrasonography and computed tomography (CT) became available. Indeed the organ still remains difficult to examine in some patients, a fact reflected in the variety of methods available to evaluate pancreatic morphology. It is something of a paradox that the pancreas is metabolically active and physiologically important but that its examination by radionuclide methods has virtually ceased to have any role in day-to-day clinical practice. To some extent this is caused by the tendency of the pancreas's commonest gross diseases emdash carcinoma and pancreatitis, for example emdash to result in nonfunction of the entire organ. Disorders of pancreatic endocrine function have generally not required imaging methods for diagnosis, although an understanding of diabetes mellitus and its nosology has been advanced by radioimmunoassay of plasma insulin concentrations

  15. Radionuclide transfer

    International Nuclear Information System (INIS)

    Gerber, G.B.

    1993-01-01

    The research project described here had the aim to obtain further information on the transfer of nuclides during pregnancy and lactation. The tests were carried out in mini-pigs and rats receiving unchanging doses of radionuclides with the food. The following findings were revealed for the elements examined: Fe, Se, Cs and Zn were characterized by very high transfer levels in the mother, infant and foetus. A substantial uptake by the mother alone was observed for Co, Ag and Mn. The uptake by the foetus and infant here was 1 to 10 times lower. A preferential concentration in certain tissues was seen for Sr and Tc; the thyroid levels of Tc were about equally high in mothers and infants, while Sr showed less accumulation in the maternal bone. The lanthanide group of substances (Ce, Eu and Gd as well as Y and Ru) were only taken up to a very limited extent. The uptake of the examined radionuclides (Fe, Co, Ag, Ce) with the food ingested was found here to be ten times greater in rats as compared to mini-pigs. This showed that great caution must be observed, if the behaviour of radionuclides in man is extrapolated from relevant data obtained in rodents. (orig./MG) [de

  16. Artificial Plant Root System Growth for Distributed Optimization: Models and Emergent Behaviors

    Directory of Open Access Journals (Sweden)

    Su Weixing

    2016-01-01

    Full Text Available Plant root foraging exhibits complex behaviors analogous to those of animals, including the adaptability to continuous changes in soil environments. In this work, we adapt the optimality principles in the study of plant root foraging behavior to create one possible bio-inspired optimization framework for solving complex engineering problems. This provides us with novel models of plant root foraging behavior and with new methods for global optimization. This framework is instantiated as a new search paradigm, which combines the root tip growth, branching, random walk, and death. We perform a comprehensive simulation to demonstrate that the proposed model accurately reflects the characteristics of natural plant root systems. In order to be able to climb the noise-filled gradients of nutrients in soil, the foraging behaviors of root systems are social and cooperative, and analogous to animal foraging behaviors.

  17. Feeding behavior by hummingbirds (Aves: Trochilidae in artificial food patches in an Atlantic Forest remnant in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Lucas L. Lanna

    2017-06-01

    Full Text Available ABSTRACT During flight, hummingbirds achieve the maximum aerobic metabolism rates within vertebrates. To meet such demands, these birds have to take in as much energy as possible, using strategies such as selecting the best food resources and adopting behaviors that allow the greatest energy gains. We tested whether hummingbirds choose sources that have higher sugar concentrations, and investigated their behaviors near and at food resources. The study was conducted at Atlantic forest remnant in Brazil, between June and December 2012. Four patches were provided with artificial feeders, containing sucrose solutions at concentrations of 5%, 15%, 25% and 35% weight/volume. Hummingbird behaviors were recorded using the ad libitum method with continuous recording of behaviors. The following species were observed: the Brazilian ruby Clytolaema rubricauda (Boddaert, 1783, Violet-capped woodnymph Thalurania glaucopis (Gmelin, 1788, Scale-throated hermit Phaethornis eurynome (Lesson, 1832, White-throated hummingbird Leucochloris albicollis (Vieillot, 1818, Versicoloured emerald Amazilia versicolor (Vieillot, 1818, Glittering-bellied emerald Chlorostilbon lucidus (Shaw, 1812 and other Phaethornis spp. C. rubricauda, P. eurynome and Phaethornis spp. visited the 35%-sucrose feeders more often, while the T. glaucopis visited the 25%-sucrose feeders more often. L. albicollis and A. versicolor visited more often solutions with sugar concentration of 15%. C. lucidus visited all patches equally. Three behavioral strategies were observed: 1 C. rubricauda and T. glaucopis exhibited interspecific and intraspecific dominance; 2 the remaining species exhibited subordinance to the dominant hummingbirds, and 3 P. eurynome and Phaethornis spp. adopted a hide-and-wait strategy to the dominant hummingbird species. The frequency of aggressive behaviors was correlated with the time the hummingbird spent feeding, and bird size. Our results showed that hummingbirds can adopt

  18. Amounts of artificial food colors in commonly consumed beverages and potential behavioral implications for consumption in children.

    Science.gov (United States)

    Stevens, Laura J; Burgess, John R; Stochelski, Mateusz A; Kuczek, Thomas

    2014-02-01

    Artificial food colors (AFCs) are widely used to color foods and beverages. The amount of AFCs the Food and Drug Administration has certified over the years has increased more than 5-fold since 1950 (12 mg/capita/day) to 2012 (68 mg/capita/day). In the past 38 years, there have been studies of adverse behavioral reactions such as hyperactivity in children to double-blind challenges with AFCs. Studies that used 50 mg or more of AFCs as the challenge showed a greater negative effect on more children than those which used less. The study reported here is the first to quantify the amounts of AFCs in foods (specifically in beverages) commonly consumed by children in the United States. Consumption data for all foods would be helpful in the design of more challenge studies. The data summarized here should help clinicians advise parents about AFCs and beverage consumption.

  19. Corrosion behavior of AZ91 magnesium alloy treated by plasma immersion ion implantation and deposition in artificial physiological fluids

    International Nuclear Information System (INIS)

    Liu Chenglong; Xin Yunchang; Tian Xiubo; Chu, Paul K.

    2007-01-01

    Due to the good biocompatibility and tensile yield strength, magnesium alloys are promising in degradable prosthetic implants. The objective of this study is to investigate the corrosion behavior of surgical AZ91 magnesium alloy treated by aluminum, zirconium, and titanium plasma immersion ion implantation and deposition (PIII and D) at 10 kV in artificial physiological fluids. The surface layers show a characteristic intermixed layer and the outer surface are mainly composed of aluminum, zirconium or titanium oxide with a lesser amount of magnesium oxide. Comparing the three sets of samples, aluminum PIII and D significantly shifts the open circuit potential (OCP) to a more positive potential and improves the corrosion resistance at OCP

  20. An approach to modeling operator's cognitive behavior using artificial intelligence techniques in emergency operating event sequences

    International Nuclear Information System (INIS)

    Cheon, Se Woo; Sur, Sang Moon; Lee, Yong Hee; Park, Young Taeck; Moon, Sang Joon

    1994-01-01

    Computer modeling of an operator's cognitive behavior is a promising approach for the purpose of human factors study and man-machine systems assessment. In this paper, the states of the art in modeling operator behavior and the current status in developing an operator's model (MINERVA - NPP) are presented. The model is constructed as a knowledge-based system of a blackboard framework and is simulated based on emergency operating procedures

  1. Autoshaped choice in artificial neural networks: implications for behavioral economics and neuroeconomics.

    Science.gov (United States)

    Burgos, José E; García-Leal, Óscar

    2015-05-01

    An existing neural network model of conditioning was used to simulate autoshaped choice. In this phenomenon, pigeons first receive an autoshaping procedure with two keylight stimuli X and Y separately paired with food in a forward-delay manner, intermittently for X and continuously for Y. Then pigeons receive unreinforced choice test trials of X and Y concurrently present. Most pigeons choose Y. This preference for a more valuable response alternative is a form of economic behavior that makes the phenomenon relevant to behavioral economics. The phenomenon also suggests a role for Pavlovian contingencies in economic behavior. The model used, in contrast to others, predicts autoshaping and automaintenance, so it is uniquely positioned to predict autoshaped choice. The model also contemplates neural substrates of economic behavior in neuroeconomics, such as dopaminergic and hippocampal systems. A feedforward neural network architecture was designed to simulate a neuroanatomical differentiation between two environment-behavior relations X-R1 and Y-R2, [corrected] where R1 and R2 denote two different emitted responses (not unconditionally elicited by the reward). Networks with this architecture received a training protocol that simulated an autoshaped-choice procedure. Most networks simulated the phenomenon. Implications for behavioral economics and neuroeconomics, limitations, and the issue of model appraisal are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Factors influencing the transfer of radionuclides in agricultural food chains

    International Nuclear Information System (INIS)

    Vandecasteele, C.M.; Zeevaert, Th.; Kirchmann, R.

    1991-01-01

    The applications of nuclear energy have led and will continue to lead to routine or accidental discharges of radioactive elements into the atmospheric and/or aquatic environment resulting in the exposure of populations to ionising radiations. The radionuclides released into the atmosphere are transported downwind, dispersed by the atmospheric mixing phenomena and progressively settled by deposition processes. During the passage of the radioactive cloud, people are irradiated externally as well as internally by inhalation. After the passage of the cloud, exposure of the population continues via three main pathways: external irradiation from the radionuclides deposited on the ground, inhalation of resuspended contaminated particles and ingestion of contaminated food products. When discharged into aquatic systems, the radionuclides can be partly removed from the aqueous phase by adsorption on suspended solids and bottom sediments. As the radioactivity disperses, there is a continuing exchange between water and solid phases. The contaminated sediments deposited on the banks of rivers, lakes and coastal area lead to external irradiation of people spending time at these sites. The residual activity in water exposes man internally through the ingestion of drinking water and food products, contaminated by irrigation of vegetation and ingestion of water by livestock. Among the various exposure pathways, the main route of entry of fission products and most other artificial radionuclides into man has been identified as uptake from the diet. Since agricultural products constitute the basic diet of most populations, the fate and behavior of radionuclides in agricultural ecosystems are of primary importance when assessing the exposure risk of man from environmental releases of radioactivity. 69 refs., 4 figs

  3. Radionuclide radiology

    International Nuclear Information System (INIS)

    Scarsbrook, A.F.; Graham, R.N.J.; Perriss, R.W.; Bradley, K.M.

    2006-01-01

    This is the fourth in a series of short reviews of internet-based radiological educational resources, and will focus on radionuclide radiology and nuclear medicine. What follows is a list of carefully selected websites to save time in searching them out. Most of the sites cater for trainee or non-specialist radiologists, but may also be of interest to specialists for use in teaching. This article may be particularly useful to radiologists interested in the rapidly expanding field of positron emission tomography computed tomography (PET-CT). Hyperlinks are available in the electronic version of this article and were all active at the time of going to press (February 2006)

  4. Natural and artificial radionuclides in our environment

    International Nuclear Information System (INIS)

    Neu, Alfred; Bayer, Anton; Steinkopff, Thomas

    2010-01-01

    The conference proceedings cover contributions and posters concerning the following topics: emission control and monitoring, environmental radioactivity and radiation exposure; radon in the environment; radioecology and modeling: radioecology and tracer for environmental processes, modeling in environmental monitoring, environmental and geostatistics; physical metrology and radiochemical methods; regulations, regulatory standards and quality assurance.

  5. Artificial radionuclides in the atmosphere over Lithuania

    Energy Technology Data Exchange (ETDEWEB)

    Lujaniene, G. [Institute of Physics, Nuclear and Environmental Radioactivity Research Laboratory, Savanoriu 231, LT-02300 Vilnius (Lithuania)], E-mail: lujaniene@ar.fi.lt; Aninkevicius, V. [Semiconductor Physics Institute, A. Gostauto 11, LT-01108 Vilnius (Lithuania); Lujanas, V. [Institute of Physics, Nuclear and Environmental Radioactivity Research Laboratory, Savanoriu 231, LT-02300 Vilnius (Lithuania)

    2009-02-15

    Measurements of airborne radioactive aerosol concentration were carried out on the basis of 1-3 days samples after the Chernobyl disaster and during the period of 1992-2003. Transport of 'hot' particles of different composition resulted in the high activity concentrations of {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu and {sup 241}Am in the atmosphere in Vilnius at the end of April 1986. The {sup 240}Pu/{sup 239}Pu atom ratio showed clear evidence of non-global plutonium originating from the Chernobyl accident in the atmosphere over Lithuania. The {sup 240}Pu/{sup 239}Pu atom ratio ranged from 0.14 to 0.40 in monthly samples in Vilnius in 1995-2003. An increase in activity concentration of {sup 137}Cs by a factor of 100 (up to 300 {mu}Bq/m{sup 3}) was found following forest fires in the Ukraine and Belarus. However, no transport of the Chernobyl plutonium was observed and the {sup 240}Pu/{sup 239}Pu atom ratio in samples collected during the forest fires was found to be 0.229 and 0.185, respectively. The exponential decrease in the {sup 240}Pu/{sup 239}Pu atom ratio from 0.30 to 0.19 (mean values) was observed in 1995-2003.

  6. Nanostructured complex oxides as a route towards thermal behavior in artificial spin ice systems

    Science.gov (United States)

    Chopdekar, R. V.; Li, B.; Wynn, T. A.; Lee, M. S.; Jia, Y.; Liu, Z. Q.; Biegalski, M. D.; Retterer, S. T.; Young, A. T.; Scholl, A.; Takamura, Y.

    2017-07-01

    We have used soft x-ray photoemission electron microscopy to image the magnetization of single-domain L a0.7S r0.3Mn O3 nanoislands arranged in geometrically frustrated configurations such as square ice and kagome ice geometries. Upon thermal randomization, ensembles of nanoislands with strong interisland magnetic coupling relax towards low-energy configurations. Statistical analysis shows that the likelihood of ensembles falling into low-energy configurations depends strongly on the annealing temperature. Annealing to just below the Curie temperature of the ferromagnetic film (TC=338 K ) allows for a much greater probability of achieving low-energy configurations as compared to annealing above the Curie temperature. At this thermally active temperature of 325 K, the ensemble of ferromagnetic nanoislands explore their energy landscape over time and eventually transition to lower energy states as compared to the frozen-in configurations obtained upon cooling from above the Curie temperature. Thus, this materials system allows for a facile method to systematically study thermal evolution of artificial spin ice arrays of nanoislands at temperatures modestly above room temperature.

  7. Multiscale Modeling of Gene-Behavior Associations in an Artificial Neural Network Model of Cognitive Development

    Science.gov (United States)

    Thomas, Michael S. C.; Forrester, Neil A.; Ronald, Angelica

    2016-01-01

    In the multidisciplinary field of developmental cognitive neuroscience, statistical associations between levels of description play an increasingly important role. One example of such associations is the observation of correlations between relatively common gene variants and individual differences in behavior. It is perhaps surprising that such…

  8. The effects of behavioral and structural assumptions in artificial stock market

    Science.gov (United States)

    Liu, Xinghua; Gregor, Shirley; Yang, Jianmei

    2008-04-01

    Recent literature has developed the conjecture that important statistical features of stock price series, such as the fat tails phenomenon, may depend mainly on the market microstructure. This conjecture motivated us to investigate the roles of both the market microstructure and agent behavior with respect to high-frequency returns and daily returns. We developed two simple models to investigate this issue. The first one is a stochastic model with a clearing house microstructure and a population of zero-intelligence agents. The second one has more behavioral assumptions based on Minority Game and also has a clearing house microstructure. With the first model we found that a characteristic of the clearing house microstructure, namely the clearing frequency, can explain fat tail, excess volatility and autocorrelation phenomena of high-frequency returns. However, this feature does not cause the same phenomena in daily returns. So the Stylized Facts of daily returns depend mainly on the agents’ behavior. With the second model we investigated the effects of behavioral assumptions on daily returns. Our study implicates that the aspects which are responsible for generating the stylized facts of high-frequency returns and daily returns are different.

  9. Geochemical behavior of radionuclides and heavy metals in soils from Corumbatai River basin (SP), Brazil; Comportamento geoquimico de radionuclideos e metais pesados em solos da bacia do Rio Corumbatai (SP)

    Energy Technology Data Exchange (ETDEWEB)

    Conceicao, Fabiano Tomazini da

    2004-07-01

    The purpose of this research was to study the geochemical behavior of radionuclides and heavy metals in soils of agricultural use at Corumbatai River basin (SP). The natural concentration and variability in sedimentary rocks at Corumbatai river basin follow the trend Ca > Mg > K > Na, with the concentration of heavy metals and radionuclides. The distribution of exposure rate in soils shows the occurrence of higher values towards south of the Corumbatai river basin, region where are applied phosphate fertilizers, amendments and 'vinhaca' in sugar cane crops. Heavy metals and radionuclides incorporated in phosphate fertilizers and amendments are annually added during the fertilization process in the sugar cane crops, but if they are utilized in accordance with the recommended rate, they do not rise the concentration levels in soils up to hazards levels. Thus, they are lower transferred from soils to sugar cane at Corumbatai river basin, not offering hazard to the ecosystem and animal or human health. (author)

  10. Geochemical behavior of radionuclides and heavy metals in soils from Corumbatai River basin (SP), Brazil; Comportamento geoquimico de radionuclideos e metais pesados em solos da bacia do Rio Corumbatai (SP)

    Energy Technology Data Exchange (ETDEWEB)

    Conceicao, Fabiano Tomazini da

    2004-07-01

    The purpose of this research was to study the geochemical behavior of radionuclides and heavy metals in soils of agricultural use at Corumbatai River basin (SP). The natural concentration and variability in sedimentary rocks at Corumbatai river basin follow the trend Ca > Mg > K > Na, with the concentration of heavy metals and radionuclides. The distribution of exposure rate in soils shows the occurrence of higher values towards south of the Corumbatai river basin, region where are applied phosphate fertilizers, amendments and 'vinhaca' in sugar cane crops. Heavy metals and radionuclides incorporated in phosphate fertilizers and amendments are annually added during the fertilization process in the sugar cane crops, but if they are utilized in accordance with the recommended rate, they do not rise the concentration levels in soils up to hazards levels. Thus, they are lower transferred from soils to sugar cane at Corumbatai river basin, not offering hazard to the ecosystem and animal or human health. (author)

  11. Artificial-Crack-Behavior Test Evaluation of the Water-Leakage Repair Materials Used for the Repair of Water-Leakage Cracks in Concrete Structures

    OpenAIRE

    Soo-Yeon Kim; Sang-Keun Oh; Byoungil Kim

    2016-01-01

    There are no existing standard test methods at home and abroad that can verify the performance of water leakage repair materials, and it is thus very difficult to perform quality control checks in the field of water leakage repair. This study determined that the key factors that have the greatest impact on the water leakage repair materials are the micro-behaviors of cracks, and proposed an artificial-crack-behavior test method for the performance verification of the repair materials. The per...

  12. Mobility and Bioavailability of Radionuclides in Soils

    International Nuclear Information System (INIS)

    Iurian, A.; Olufemi Phaneuf, M.; Mabit, L.

    2016-01-01

    It is crucial to understand the behavior of radionuclides in the environment, their potential mobility and bioavailability related to long-term persistence, radiological hazards, and impact on human health. Such key information is used to develop strategies that support policy decisions. The environmental behavior of radionuclides depends on ecosystem characteristics. A given soil’s capacity to immobilize radionuclides has been proved to be the main factor responsible for their resulting activity concentrations in plants. The mobility and bioavailability of radionuclides in soils is complex, depending on clay-sized soil fraction, clay mineralogy, organic matter, cation exchange capacity, pH and quantities of competing cations. Moreover, plant species have different behaviors regarding radionuclide absorption depending on soil and plan characteristics

  13. Whitefly feeding behavior and retention of a foregut-borne crinivirus exposed to artificial diets with different pH values.

    Science.gov (United States)

    Zhou, Jaclyn S; Chen, Angel Y S; Drucker, Martin; Lopez, Nicole H; Carpenter, Alyssa; Ng, James C K

    2017-12-01

    Transmission of plant viruses by phytophagous hemipteran insects encompasses complex interactions underlying a continuum of processes involved in virus acquisition, retention and inoculation combined with vector feeding behavior. Here, we investigated the effects of dietary pH on whitefly (Bemisia tabaci) feeding behavior and release of Lettuce infectious yellows virus (LIYV) virions retained in the vector's foregut. Electrical penetration graph analysis revealed that variables associated with whitefly probing and ingestion did not differ significantly in pH (4, 7.4, and 9) adjusted artificial diets. To investigate virus retention and release, whiteflies allowed to acquire LIYV virions in a pH 7.4 artificial diet were fed pH 4, 7.4, or 9 virion-free artificial (clearing) diets. Immunofluorescent localization analyses indicated that virions remained bound to the foreguts of approximately 20%-24% of vectors after they fed on each of the 3 pH-adjusted clearing diets. When RNA preparations from the clearing diets were analyzed by reverse transcription (RT) nested-PCR and, in some cases, real-time qPCR, successful amplification of LIYV-specific sequence was infrequent but consistently repeatable for the pH 7.4 diet but never observed for the pH 4 and 9 diets, suggesting a weak pH-dependent effect for virion release. Viruliferous vectors that fed on each of the 3 pH-adjusted clearing diets transmitted LIYV to virus-free plants. These results suggest that changes in pH values alone in artificial diet do not result in observable changes in whitefly feeding behaviors, an observation that marks a first in the feeding of artificial diet by whitefly vectors; and that there is a potential causal and contingent relationship between the pH in artificial diet and the release/inoculation of foregut bound virions. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  14. Radioactivity and the environment: technical approaches to understand the role of arbuscular mycorrhizal plants in radionuclide bioaccumulation

    Science.gov (United States)

    Davies, Helena S.; Cox, Filipa; Robinson, Clare H.; Pittman, Jon K.

    2015-01-01

    Phytoaccumulation of radionuclides is of significant interest with regards to monitoring radionuclide build-up in food chains, developing methods for environmental bioremediation and for ecological management. There are many gaps in our understanding of the characteristics and mechanisms of plant radionuclide accumulation, including the importance of symbiotically-associated arbuscular mycorrhizal (AM) fungi. We first briefly review the evidence that demonstrates the ability of AM fungi to enhance the translocation of 238U into plant root tissues, and how fungal association may prevent further mobilization into shoot tissues. We then focus on approaches that should further advance our knowledge of AM fungi–plant radionuclide accumulation. Current research has mostly used artificial cultivation methods and we consider how more ecologically-relevant analysis might be performed. The use of synchrotron-based X-ray fluorescence imaging and absorption spectroscopy techniques to understand the mechanisms of radionuclide transfer from soil to plant via AM fungi is evaluated. Without such further knowledge, the behavior and mobilization of radionuclides cannot be accurately modeled and the potential risks cannot be accurately predicted. PMID:26284096

  15. Behavioral Responses of Concholepas concholepas (Bruguière, 1789) Larvae to Natural and Artificial Settlement Cues and Microbial Films.

    Science.gov (United States)

    Rodriguez, S R; Riquelme, C; Campos, E O; Chavez, P; Brandan, E; Inestrosa, N C

    1995-12-01

    The behavioral responses of veliger larvae of the gastropod Concholepas concholepas were studied in the presence of different natural and artificial settlement cues and microbial films. Early pre-competent larvae stopped swimming, sank (due to ciliary arrests, retraction of the velum into the shell, or both), and remained inactive on the substratum when exposed to conspecific mucus and hemolymph. In both cases the effect was time-dependent and the number of larvae showing these behaviors decreased over time. Larvae exposed to NH4Cl (ammonium ion) showed a similar time- and dose-dependent response. A positive and time-dependent response was also observed when larvae were exposed to different extracellular matrix (ECM) components (i.e., collagen, gelatin, and fibronectin) and sulfated polysaccharides (i.e., carrageenan, heparin, and chondroitin sulfate). In this case the larvae remained attached to the substratum. However, the effect of sulfated polysaccharides on C. concholepas larval behavior was faster than that observed with other ECM molecules. We also studied the responses of premetamorphic C. concholepas larvae exposed to different microbial films. In chemotaxis experiments with different films, with glass as the substratum, larvae showed a significant preference for multispecific and diatoms films. When shells of C. concholepas were used as the substratum, the preference for multispecific films was clear and significant. Likewise, larvae showed velar contractions in the presence of all the films tested. Larvae exposed to multispecific films and to the microalga Prasinocladus marinus showed an increased ciliar movement. The finding that mucus and hemolymph of conspecific adults and ECM molecules (mainly sulfated polysaccharides) induce the cessation of swimming of C. concholepas larvae suggests a possible role for cell-surface receptors in mediating the larval response of marine organisms. Likewise, the positive chemotaxis responses of C. concholepas larvae to

  16. All-union Conference. Principles and methods of regional and geochemical investigations into radionuclide migration

    International Nuclear Information System (INIS)

    Khitrov, L.M.

    1989-01-01

    The collection presents abstracts of papers concerning landscape-geochemical research of radionuclides migration; aspects of 'hot particles' study; radionuclides forms and behaviour in soils, in soil-plant; soil-natural water systems, as well as in water ecosystems. Methods of natural objects artificial radioactivity study are reviewed. Distribution of natural radionuclides in soils. natural waters, etc. is discussed

  17. Study on torsional fretting wear behavior of a ball-on-socket contact configuration simulating an artificial cervical disk

    International Nuclear Information System (INIS)

    Wang, Song; Wang, Fei; Liao, Zhenhua; Wang, Qingliang; Liu, Yuhong; Liu, Weiqiang

    2015-01-01

    A ball-on-socket contact configuration was designed to simulate an artificial cervical disk in structure. UHMWPE (ultra high molecular weight polyethylene) hot pressed by powders and Ti6Al4V alloy were selected as the material combination of ball and socket. The socket surface was coated by a ~ 500 nm C-DLC (carbon ion implantation-diamond like carbon) mixed layer to improve its surface nano hardness and wear resistance. The torsional fretting wear behavior of the ball-on-socket model was tested at different angular displacements under 25% bovine serum lubrication with an axial force of 100 N to obtain more realistic results with that in vivo. The fretting running regimes and wear damage characteristics as well as wear mechanisms for both ball and socket were studied based on 2D (two dimension) optical microscope, SEM (scanning electron microscope) and 3D (three dimension) profiles. With the increase of angular displacement amplitude from 1° to 7°, three types of T-θ (Torsional torque-angular displacement amplitude) curves (i.e., linear, elliptical and parallelogram loops) corresponding to running regimes of PSR (partial slip regime), MR (mixed regime) and SR (slip regime) were observed and analyzed. Both the central region and the edge zone of the ball and socket were damaged. The worn surfaces were characterized by wear scratches and wear debris. In addition, more severe wear damage and more wear debris appeared on the central region of the socket at higher angular displacement amplitude. The dominant damage mechanism was a mix of surface scratch, adhesive wear and abrasive wear for the UHMWPE ball while that for the coated socket was abrasive wear by PE particles and some polishing and rolling process on the raised overgrown DLC grains. The frictional kinetic behavior, wear type, damage region and damage mechanism for the ball-on-socket model revealed significant differences with those of a ball-on-flat contact while showing better consistency with that of in

  18. Study on torsional fretting wear behavior of a ball-on-socket contact configuration simulating an artificial cervical disk

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Song [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Wang, Fei [School of Material Science and Engineering, China University of Mining and Technology, Xuzhou 221116 (China); Liao, Zhenhua [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Wang, Qingliang [School of Material Science and Engineering, China University of Mining and Technology, Xuzhou 221116 (China); Liu, Yuhong [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Liu, Weiqiang, E-mail: weiqliu@hotmail.com [Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China)

    2015-10-01

    A ball-on-socket contact configuration was designed to simulate an artificial cervical disk in structure. UHMWPE (ultra high molecular weight polyethylene) hot pressed by powders and Ti6Al4V alloy were selected as the material combination of ball and socket. The socket surface was coated by a ~ 500 nm C-DLC (carbon ion implantation-diamond like carbon) mixed layer to improve its surface nano hardness and wear resistance. The torsional fretting wear behavior of the ball-on-socket model was tested at different angular displacements under 25% bovine serum lubrication with an axial force of 100 N to obtain more realistic results with that in vivo. The fretting running regimes and wear damage characteristics as well as wear mechanisms for both ball and socket were studied based on 2D (two dimension) optical microscope, SEM (scanning electron microscope) and 3D (three dimension) profiles. With the increase of angular displacement amplitude from 1° to 7°, three types of T-θ (Torsional torque-angular displacement amplitude) curves (i.e., linear, elliptical and parallelogram loops) corresponding to running regimes of PSR (partial slip regime), MR (mixed regime) and SR (slip regime) were observed and analyzed. Both the central region and the edge zone of the ball and socket were damaged. The worn surfaces were characterized by wear scratches and wear debris. In addition, more severe wear damage and more wear debris appeared on the central region of the socket at higher angular displacement amplitude. The dominant damage mechanism was a mix of surface scratch, adhesive wear and abrasive wear for the UHMWPE ball while that for the coated socket was abrasive wear by PE particles and some polishing and rolling process on the raised overgrown DLC grains. The frictional kinetic behavior, wear type, damage region and damage mechanism for the ball-on-socket model revealed significant differences with those of a ball-on-flat contact while showing better consistency with that of in

  19. Use of artificial intelligence to shorten the behavioral diagnosis of autism.

    Directory of Open Access Journals (Sweden)

    Dennis P Wall

    Full Text Available The Autism Diagnostic Interview-Revised (ADI-R is one of the most commonly used instruments for assisting in the behavioral diagnosis of autism. The exam consists of 93 questions that must be answered by a care provider within a focused session that often spans 2.5 hours. We used machine learning techniques to study the complete sets of answers to the ADI-R available at the Autism Genetic Research Exchange (AGRE for 891 individuals diagnosed with autism and 75 individuals who did not meet the criteria for an autism diagnosis. Our analysis showed that 7 of the 93 items contained in the ADI-R were sufficient to classify autism with 99.9% statistical accuracy. We further tested the accuracy of this 7-question classifier against complete sets of answers from two independent sources, a collection of 1654 individuals with autism from the Simons Foundation and a collection of 322 individuals with autism from the Boston Autism Consortium. In both cases, our classifier performed with nearly 100% statistical accuracy, properly categorizing all but one of the individuals from these two resources who previously had been diagnosed with autism through the standard ADI-R. Our ability to measure specificity was limited by the small numbers of non-spectrum cases in the research data used, however, both real and simulated data demonstrated a range in specificity from 99% to 93.8%. With incidence rates rising, the capacity to diagnose autism quickly and effectively requires careful design of behavioral assessment methods. Ours is an initial attempt to retrospectively analyze large data repositories to derive an accurate, but significantly abbreviated approach that may be used for rapid detection and clinical prioritization of individuals likely to have an autism spectrum disorder. Such a tool could assist in streamlining the clinical diagnostic process overall, leading to faster screening and earlier treatment of individuals with autism.

  20. Use of artificial intelligence to shorten the behavioral diagnosis of autism.

    Science.gov (United States)

    Wall, Dennis P; Dally, Rebecca; Luyster, Rhiannon; Jung, Jae-Yoon; Deluca, Todd F

    2012-01-01

    The Autism Diagnostic Interview-Revised (ADI-R) is one of the most commonly used instruments for assisting in the behavioral diagnosis of autism. The exam consists of 93 questions that must be answered by a care provider within a focused session that often spans 2.5 hours. We used machine learning techniques to study the complete sets of answers to the ADI-R available at the Autism Genetic Research Exchange (AGRE) for 891 individuals diagnosed with autism and 75 individuals who did not meet the criteria for an autism diagnosis. Our analysis showed that 7 of the 93 items contained in the ADI-R were sufficient to classify autism with 99.9% statistical accuracy. We further tested the accuracy of this 7-question classifier against complete sets of answers from two independent sources, a collection of 1654 individuals with autism from the Simons Foundation and a collection of 322 individuals with autism from the Boston Autism Consortium. In both cases, our classifier performed with nearly 100% statistical accuracy, properly categorizing all but one of the individuals from these two resources who previously had been diagnosed with autism through the standard ADI-R. Our ability to measure specificity was limited by the small numbers of non-spectrum cases in the research data used, however, both real and simulated data demonstrated a range in specificity from 99% to 93.8%. With incidence rates rising, the capacity to diagnose autism quickly and effectively requires careful design of behavioral assessment methods. Ours is an initial attempt to retrospectively analyze large data repositories to derive an accurate, but significantly abbreviated approach that may be used for rapid detection and clinical prioritization of individuals likely to have an autism spectrum disorder. Such a tool could assist in streamlining the clinical diagnostic process overall, leading to faster screening and earlier treatment of individuals with autism.

  1. Drift-Scale Radionuclide Transport

    International Nuclear Information System (INIS)

    Houseworth, J.

    2004-01-01

    drift. The reason for introducing the fracture-matrix partitioning model is to broaden the conceptual model for flow beneath waste emplacement drifts in a way that does not rely on the specific flow behavior predicted by a dual continuum model and to ensure that radionuclide transport is not underestimated. The fracture-matrix partitioning model provides an alternative method of computing the partitioning of radionuclide releases from drifts without seepage into rock fractures and rock matrix. Drifts without seepage are much more likely to have a significant fraction of radionuclide releases into the rock matrix, and therefore warrant additional attention in terms of the partitioning model used for TSPA

  2. The effect of trace additions of Zn on the precipitation behavior of alloy 8090 during artificial aging

    Science.gov (United States)

    Kilmer, R. J.; Stoner, G. E.

    1991-01-01

    The effect(s) of trace additions of Zn to the artificial aging behavior of alloy 8090 (Al-Li-Cu-Mg-Zr) was investigated in the approximate composition range 0-1 wt-pct Zn. Trace Zn additions were found to delay aging and under equivalent aging treatments (100 hrs at 160 C) the alloy without Zn and the 1.07 wt-pct Zn alloy developed delta-prime-free zones along subgrain boundaries, while the alloys of 0.21 and 0.58 wt-pct Zn did not. DSC analysis indicated that Zn was being incorporated into the delta-prime, shifting it's exotherm to higher temperatures, while having little if any effect on its associated endotherm making it unlikely that it is an artifact of a solvus shift. In the 8090 + 1.07 wt-pct Zn alloy, coarse precipitates were found to reside on subgrain boundaries and EDS indicated that they were rich in Cu and Zn. It was also noted that in the Zn containing 8090 varients, the S prime precipitates were more coarse in size than the baseline 8090.

  3. Effect of protein adsorption on the corrosion behavior of 70Cu-30Ni alloy in artificial seawater.

    Science.gov (United States)

    Torres Bautista, Blanca E; Carvalho, Maria L; Seyeux, Antoine; Zanna, Sandrine; Cristiani, Pierangela; Tribollet, Bernard; Marcus, Philippe; Frateur, Isabelle

    2014-06-01

    Copper alloys often used in cooling circuits of industrial plants can be affected by biocorrosion induced by biofilm formation. The objective of this work was to study the influence of protein adsorption, which is the first step in biofilm formation, on the electrochemical behavior of 70Cu-30Ni (wt.%) alloy in static artificial seawater and on the chemical composition of oxide layers. For that purpose, electrochemical measurements performed after 1h of immersion were combined to surface analyses. A model is proposed to analyze impedance data. In the presence of bovine serum albumin (BSA, model protein), the anodic charge transfer resistance deduced from EIS data at Ecorr is slightly higher, corresponding to lower corrosion current. Without BSA, two oxidized layers are shown by XPS and ToF-SIMS: an outer layer mainly composed of copper oxide (Cu2O redeposited layer) and an inner layer mainly composed of oxidized nickel, with a global thickness of ~30nm. The presence of BSA leads to a mixed oxide layer (CuO, Cu2O, Ni(OH)2) with a lower thickness (~10nm). Thus, the protein induces a decrease of the dissolution rate at Ecorr and hence a decrease of the amount of redeposited Cu2O and of the oxide layer thickness. © 2013.

  4. Behavior of nine selected emerging trace organic contaminants in an artificial recharge system supplemented with a reactive barrier.

    Science.gov (United States)

    Valhondo, Cristina; Carrera, Jesús; Ayora, Carlos; Barbieri, Manuela; Nödler, Karsten; Licha, Tobias; Huerta, Maria

    2014-10-01

    Artificial recharge improves several water quality parameters, but has only minor effects on recalcitrant pollutants. To improve the removal of these pollutants, we added a reactive barrier at the bottom of an infiltration basin. This barrier contained aquifer sand, vegetable compost, and clay and was covered with iron oxide dust. The goal of the compost was to sorb neutral compounds and release dissolved organic carbon. The release of dissolved organic carbon should generate a broad range of redox conditions to promote the transformation of emerging trace organic contaminants (EOCs). Iron oxides and clay increase the range of sorption site types. In the present study, we examined the effectiveness of this barrier by analyzing the fate of nine EOCs. Water quality was monitored before and after constructing the reactive barrier. Installation of the reactive barrier led to nitrate-, iron-, and manganese-reducing conditions in the unsaturated zone below the basin and within the first few meters of the saturated zone. Thus, the behavior of most EOCs changed after installing the reactive barrier. The reactive barrier enhanced the removal of some EOCs, either markedly (sulfamethoxazole, caffeine, benzoylecgonine) or slightly (trimethoprim) and decreased the removal rates of compounds that are easily degradable under aerobic conditions (ibuprofen, paracetamol). The barrier had no remarkable effect on 1H-benzotriazole and tolyltriazole.

  5. Deposition behavior of polystyrene latex particles on solid surfaces during migration through an artificial fracture in a granite rock sample

    International Nuclear Information System (INIS)

    Chinju, Hirofumi; Tanaka, Satoru; Kuno, Yoshio

    2001-01-01

    The deposition behavior of colloids during transport through heterogeneous media was observed by conducting column experiments to study migration of polystyrene latex particles (diameter=309 nm) through columns packed with artificially fractured granite rock (length=300 and 150 mm). The experiments were conducted under conditions of different ionic strengths and flow rates. The results were similar to those for colloid deposition in columns packed with glass beads reported previously; the colloid breakthrough curves showed three stages, characterized by different rates of change in the concentration of effluent. Colloid deposition on the fracture surfaces was described by considering strong and weak deposition sites. Scanning Electron Microscopy (SEM) observations indicated the existence of strong and weak sites on the fracture surfaces regardless of mineral composition. The observations also showed that the strong deposition sites tended to exist on surface irregularities such as cracks or protrusions. The degree of colloid deposition increased with increasing ionic strength and decreasing flow rate. The dependencies on ionic strength and flow rate agreed qualitatively with the DLVO theory and the previous experimental results, respectively. (author)

  6. Concentration of some radionuclides in some popular sudanese medicinal plants

    International Nuclear Information System (INIS)

    Sagiroun, M. I. A.

    2012-10-01

    In this study was measured concentration of naturally occurring radionuclides 2 38U , 2 32T h and 4 0K in samples of sudanese medicinal plants. The radionuclide activity concentrations in samples analyzed ranged from 4.09 to 41.07 Bq kg -1 for 2 38T h and from 353.14 to 2270.21 Bq kg -1 for 4 0k . No trace of artificial radionuclide was determined in all the samples. The effective dose due to the presence of these radionuclides was estimated and found to be 0.524 mSv/year which is well below the permissible levels. (Author)

  7. Migration of heavy natural radionuclides in a humid climatic zone

    International Nuclear Information System (INIS)

    Titaeva, N.A.; Alexakhin, R.M.; Taskaev, A.I.; Maslov, V.I.

    1980-01-01

    Regularities and biochemical peculiarities of the migrations of heavy natural radionuclides in the environment are examined, with special reference to two regions in a humid climatic zone representing natural patterns of radionuclide distribution and to four plots artificially contaminated with high levels of natural radioactivity more than 20 years previously. It was determined that the migration of thorium, uranium, and radium isotopes through the rock-water-soil-plant system is dependent on many physiochemical properties of these radionuclides, their compounds, and the local environment. Isotopic activity ratios provide a useful tool for studying the direction of radionuclide migration and its influence on observed distribution patterns

  8. Final Report (BMWi Project No.: 02 E 10971): Joint project: Retention of radionuclides relevant for final disposal in natural clay rock and saline systems - Subproject 2: Geochemical behavior and transport of radionuclides in saline systems in the prese

    Energy Technology Data Exchange (ETDEWEB)

    Schmeide, Katja [Helmholtz-Zentrum Dresden, (Germany). Inst. of Resource Ecology; Fritsch, Katharina [Helmholtz-Zentrum Dresden, (Germany). Inst. of Resource Ecology; Lippold, Holger [Helmholtz-Zentrum Dresden, (Germany). Inst. of Resource Ecology; Poetsch, Maria [Helmholtz-Zentrum Dresden, (Germany). Inst. of Resource Ecology; Kulenkampff, Johannes [Helmholtz-Zentrum Dresden, (Germany). Inst. of Resource Ecology; Lippmann-Pipke, Johanna [Helmholtz-Zentrum Dresden, (Germany). Inst. of Resource Ecology; Jordan, Norbert [Helmholtz-Zentrum Dresden, (Germany). Inst. of Resource Ecology; Joseph, Claudia [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Helmholtz-Zentrum Dresden, (Germany). Inst. of Resource Ecology; Moll, Henry [Helmholtz-Zentrum Dresden, (Germany). Inst. of Resource Ecology; Cherkouk, Andrea [Helmholtz-Zentrum Dresden, (Germany). Inst. of Resource Ecology; Bader, Miriam [Helmholtz-Zentrum Dresden, (Germany). Inst. of Resource Ecology

    2016-02-29

    The objective of this project was to study the influence of increased salinities on interaction processes in the system radionuclide – organics – clay – aquifer. For this, complexation, redox, sorption, and diffusion studies were performed under variation of the ionic strength (up to 4 mol kg-1) and the background electrolyte (NaCl, CaCl2, MgCl2).

  9. A Mediator Role of Perceived Organizational Support in Workplace Deviance Behaviors, Organizational Citizenship and Job Satisfaction Relations: A Survey Conducted With Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Kürşad Zorlu

    2016-01-01

    Full Text Available The aim of the research is to estimate the effect of workplace deviance behavior on organizational citizenship and job satisfaction and to put forward the mediator role of the organizational support perception in possible relations. The information based on hypothetical and literature are provided in the research principally and then the research part including the questionnaire applied to the employees of Kirsehir Municipality is presented. The validity and reliability tests have been performed successfully and the artificial neural network method has been used as the analysis method. In parallel with the averages and correlation values of the variables in the analysis the Artificial Neural Networks have been modelled by determining the inputs and outputs. In accordance with the findings obtained the workplace deviance behavior has a negative impact on the organizational citizenship and job satisfaction and the organizational support perception can take the mediator role as a relative for eliminating the abovementioned effect. When the artificial neural networks’ being used as the analysis method and the difficulties in measuring the workplace deviance behavior are taken into consideration it can be stated that the findings obtained have at a certain level of originality in terms of management discipline.

  10. A Mediator Role of Perceived Organizational Support in Workplace Deviance Behaviors, Organizational Citizenship and Job Satisfaction Relations: A Survey Conducted With Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Kursad Zorlu

    2014-07-01

    Full Text Available The aim of the research is to estimate the effect of workplace deviance behavior on organizational citizenship and job satisfaction and to put forward the mediator role of the organizational support perception in possible relations. The information based on hypothetical and literature are provided in the research principally and then the research part including the questionnaire applied to the employees of Kirsehir Municipality is presented. The validity and reliability tests have been performed successfully and the artificial neural network method has been used as the analysis method. In parallel with the averages and correlation values of the variables in the analysis the Artificial Neural Networks have been modelled by determining the inputs and outputs. In accordance with the findings obtained the workplace deviance behavior has a negative impact on the organizational citizenship and job satisfaction and the organizational support perception can take the mediator role as a relative for eliminating the abovementioned effect. When the artificial neural networks’ being used as the analysis method and the difficulties in measuring the workplace deviance behavior are taken into consideration it can be stated that the findings obtained have at a certain level of originality in terms of management discipline.

  11. Behavior of radionuclides and related elements in plants. Screening and characterization of cesium requirement mutants from mutagenized arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Yamagami, Mutsumi; Yanai, Masumi; Hisamatsu, Shunichi; Inaba, Jiro [Inst. for Environmental Sciences, Rokkasho, Aomori (Japan)

    2002-07-01

    We have investigated the effect of climate on the metabolic behavior of various elements in a specific plant. The following items have been examined: the effect of climate conditions including Yamase (prevailing windows from the Pacific Ocean side area of Aomori Prefecture) on the elemental transfer factor of rice, the effect of light conditions on metabolism of elements in a plant, the effect of environmental factors on elemental movements at a cell level, and establishment of a mutant plant strain to obtain elemental requirement. This paper describes the development of a method for screening and characterizing cesium resistance mutants from Arabidopsis thaliana. Arabidopsis is a small herbaceous plant which is used for experimental molecular botany. To isolate mutant in cesium uptake or accumulation, we have devised a screening method using energy-dispersive x-ray microanalysis (EDX) of mutagenized Arabidopsis leaves. The seeds for the selection were M{sub 2} seeds derived from ethyl methane sulfonate (EMS)-treated plants. A double screening method was used to isolate about 50 Cs-resistant mutants. In the first screening experiment, EMS-mutagenized seeds were grown in medium containing 3 mM Cs. The wild type Arabidopsis usually died, but Cs-resistant mutants survived. These were transferred into soil for harvest of first-screening-seeds. In the successive experiment, first-screening-seeds were grown in medium containing 1 mM Cs, and Cs of the leaves was analyzed by EDX. We identified about 50 mutants in Cs uptake or accumulation after screening over 100,000 seedlings. These mutants showed either excessive accumulation of Cs in leaves or an inability to accumulate Cs at a normal concentration. The uptake rates of Cs in those mutants were also examined by using {sup 134}Cs radioactive tracer. (author)

  12. Artificial-Crack-Behavior Test Evaluation of the Water-Leakage Repair Materials Used for the Repair of Water-Leakage Cracks in Concrete Structures

    Directory of Open Access Journals (Sweden)

    Soo-Yeon Kim

    2016-09-01

    Full Text Available There are no existing standard test methods at home and abroad that can verify the performance of water leakage repair materials, and it is thus very difficult to perform quality control checks in the field of water leakage repair. This study determined that the key factors that have the greatest impact on the water leakage repair materials are the micro-behaviors of cracks, and proposed an artificial-crack-behavior test method for the performance verification of the repair materials. The performance of the 15 kinds of repair materials that are currently being used in the field of water leakage repair was evaluated by applying the proposed test method. The main aim of such a test method is to determine if there is water leakage by injecting water leakage repair materials into a crack behavior test specimen with an artificial 5-mm crack width, applying a 2.5 mm vertical behavior load at 100 cycles, and applying 0.3 N/mm2 constant water pressure. The test results showed that of the 15 kinds of repair materials, only two effectively sealed the crack and thus stopped the water leakage. The findings of this study confirmed the effectiveness of the proposed artificial-crack-behavior test method and suggest that it can be used as a performance verification method for checking the responsiveness of the repair materials being used in the field of water leakage repair to the repetitive water leakage behaviors that occur in concrete structures. The study findings further suggest that the use of the proposed test method makes it possible to quantify the water leakage repair quality control in the field.

  13. Transcuticular translocation of radionuclides on plant leaf surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Ken-ichi; Watanabe, Tadakazu; Ambe, Shizuko; Yamaguchi, Isamu [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1996-12-31

    The cuticle covering all the outermost surfaces of the aerial parts of plants could play a selective role in uptake and translocation of radionuclides from air into plants. In this study, we investigated the transcuticular uptake and translocation behavior via water droplets of various radionuclides in red clover, orchard grass, Japanese radish and mung bean. Ten {mu}l of an aqueous solution of the multitracer generated from Au was applied to the upper surface of the 2nd leaf of the plants at the 5th leaf stage. The plants were then grown for 14 days at 25degC and 70% RH under illumination of artificial solar lights. The transcuticular uptake and translocation throughout the plant were periodically assayed by determining the radioactivity in the surface residue, the cuticle layer beneath the applied site, the leaf area outside the applied site, the other aerial parts and the root of the plant, using an HPGe detector. The applied radionuclides were absorbed into, in turn, the cuticle layer beneath the applied site and then translocated through the cuticle to the inner tissue and eventually to the other aerial parts and finally to the roots, of the plant. The distribution and accumulation in the plant seems to depend upon the characteristics of each radionuclide and plant species. Ca{sup *} and Te{sup *} tended to remain on leaf surfaces without being absorbed into the cuticle. On the other hand, Sc{sup *}, Co{sup *}, Zn{sup *}, Se{sup *}, Rb{sup *}, and Eu{sup *} were easily absorbed and translocated to every part of the plant including the root. The other radionuclides such as Be{sup *}, Mn{sup *}, Sr{sup *}, Y{sup *}, Ba{sup *}, Ce{sup *}, Pm{sup *}, Gd{sup *}, Hf{sup *}, Yb{sup *}, Lu{sup *}, Os{sup *}, Ir{sup *}, and Pt{sup *} remained in the region close to the site of their application. The above results possibly indicate the existence of mechanisms common to these plants for selective transcuticular uptake and translocation of radionuclides within plant

  14. Behavior of plutonium and other long-lived radionuclides in Lake Michigan. I. Biological transport, seasonal cycling, and residence times in the water column

    International Nuclear Information System (INIS)

    Wahlgren, M.A.; Marshall, J.S.

    1975-01-01

    Eight operating nuclear reactors are situated on the shores of Lake Michigan, but their releases of radioactivity have been much less than that entering the lake from stratospheric fallout. Measurements of 239 , 240 Pu, 241 Am, and 137 Cs from the latter source have been made in order to study biological transport, seasonal cycling, and residence times of long-lived radionuclides in the lake. The apparent turnover times for the residual fallout 239 , 240 Pu and 137 Cs, which are present as nonfilterable, ionic forms, are about 3 to 4 y. Resuspension may be occurring at a low rate, probably through the feeding activities of benthic organisms. Transport by settling of phytodetritus and zooplankton fecal pellets is postulated to be the cause of the rapid decline of the concentration of 239 , 240 Pu in surface waters observed during summer thermal stratification of the lake, while the concentration of 137 Cs remained almost constant. Concentration factors for fallout 239 , 240 Pu, 137 Cs, and 90 Sr at various trophic levels in the food chain in Lake Michigan have been measured. Analyses of biological samples taken at various distances from the Big Rock Point Nuclear Power Plant and of plant waste discharge show that any plutonium possibly released from the recycle plutonium test fuel is too low to be detectable in the presence of fallout plutonium. Measurements of 239 , 240 Pu, 137 Cs, and 90 Sr on a comparison set of surface water and net plankton samples from all five Great Lakes indicate generally consistent behavior patterns in these lakes. (U.S.)

  15. Differences in sorption behavior of the herbicide 4-chloro-2-methylphenoxyacetic acid on artificial soils as a function of soil pre-aging.

    Science.gov (United States)

    Waldner, Georg; Friesl-Hanl, Wolfgang; Haberhauer, Georg; Gerzabek, Martin H

    The sorption behavior of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) to three different artificial soil mixtures was investigated. Artificial soils serve as model systems for improving understanding of sorption phenomena. The soils consisted of quartz, ferrihydrite, illite, montmorillonite, and charcoal. In a previous study, several selected mixtures had been inoculated with organic matter, and microbial aging (incubation) had been performed for different periods of time (3, 12, and 18 months) before conducting the sorption experiments. The effect of this pre-incubation time on the sorption behavior was determined. Interaction of MCPA with soil surfaces was monitored by aqueous phase sorption experiments, using high-performance liquid chromatography/ultraviolet and in selected cases Fourier-transformed infrared spectroscopy. The sorption behavior showed large differences between differently aged soils; Freundlich and linear sorption model fits (with sorption constants K f , 1/ n exponents, and K d values, respectively) were given for pH = 3 and the unbuffered pH of ∼7. The largest extent of sorption from diluted solutions was found on the surfaces with a pre-incubation time of 3 months. Sorption increased at acidic pH values. Regarding the influence of aging of artificial soils, the following conclusions were drawn: young artificial soils exhibit stronger sorption at lower concentrations, with a larger K f value than aged soils. A correlation with organic carbon content was not confirmed. Thus, the sorption characteristics of the soils are more influenced by the aging of the organic carbon than by the organic carbon content itself.

  16. Artificial intelligence

    CERN Document Server

    Hunt, Earl B

    1975-01-01

    Artificial Intelligence provides information pertinent to the fundamental aspects of artificial intelligence. This book presents the basic mathematical and computational approaches to problems in the artificial intelligence field.Organized into four parts encompassing 16 chapters, this book begins with an overview of the various fields of artificial intelligence. This text then attempts to connect artificial intelligence problems to some of the notions of computability and abstract computing devices. Other chapters consider the general notion of computability, with focus on the interaction bet

  17. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Allen, S.E.; Horrill, A.D.; Howard, B.J.; Lowe, V.P.W.; Parkinson, J.A.

    1983-07-01

    The subject is discussed under the headings: concentration and spatial distribution of radionuclides in grazed and ungrazed saltmarshes; incorporation of radionuclides by sheep grazing on an estuarine saltmarsh; inland transfer of radionuclides by birds feeding in the estuaries and saltmarshes at Ravenglass; radionuclides in contrasting types of coastal pastures and taken up by individual plant species found in west Cumbria; procedures developed and used for the measurement of alpha and gamma emitters in environmental materials. (U.K.)

  18. Joint project. Retention of radionuclides relevant for final disposal in natural clay rock and saline systems. Subproject 2. Geochemical behavior and transport of radionuclides in saline systems in the presence of repository-relevant organics. Final report

    International Nuclear Information System (INIS)

    Schmeide, Katja; Fritsch, Katharina; Lippold, Holger

    2016-01-01

    The objective of this project was to study the influence of increased salinities on interaction processes in the system radionuclide - organics - clay - aquifer. For this purpose, complexation, redox, sorption, and diffusion studies were performed under variation of the ionic strength (up to 4 mol kg -1 ) and the background electrolyte. The U(VI) complexation by propionate was studied in dependence on ionic strength (up to 4 mol kg -1 NaClO 4 ) by TRLFS, ATR FT-IR spectroscopy, and DFT calculations. An influence of ionic strength on stability constants was detected, depending on the charge of the respective complexes. The conditional stability constants, determined for 1:1, 1:2, and 1:3 complexes at specific ionic strengths, were extrapolated to zero ionic strength. The interaction of the bacteria Sporomusa sp. MT-2.99 and Paenibacillus sp. MT-2.2 cells, isolated from Opalinus Clay, with Pu was studied. The experiments can be divided into such without an electron donor where biosorption is favored and such with addition of Na-pyruvate as an electron donor stimulating also bioreduction processes. Moreover, experiments were performed to study the interactions of the halophilic archaeon Halobacterium noricense DSM-15987 with U(VI), Eu(III), and Cm(III) in 3 M NaCl solutions. Research for improving process understanding with respect to the mobility of multivalent metals in systems containing humic matter was focused on the reversibility of elementary processes and on their interaction. Kinetic stabilization processes in the dynamics of humate complexation equilibria were quantified in isotope exchange studies. The influence of high salinity on the mobilizing potential of humic-like clay organics was systematically investigated and was described by modeling. The sorption of Tc(VII)/Tc(IV) onto the iron(II)-containing minerals magnetite and siderite was studied by means of batch sorption experiments, ATR FT-IR and X-ray absorption spectroscopy. The strong Tc retention at

  19. Joint project. Retention of radionuclides relevant for final disposal in natural clay rock and saline systems. Subproject 2. Geochemical behavior and transport of radionuclides in saline systems in the presence of repository-relevant organics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schmeide, Katja; Fritsch, Katharina; Lippold, Holger [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Ressource Ecology; and others

    2016-08-01

    The objective of this project was to study the influence of increased salinities on interaction processes in the system radionuclide - organics - clay - aquifer. For this purpose, complexation, redox, sorption, and diffusion studies were performed under variation of the ionic strength (up to 4 mol kg{sup -1}) and the background electrolyte. The U(VI) complexation by propionate was studied in dependence on ionic strength (up to 4 mol kg{sup -1} NaClO{sub 4}) by TRLFS, ATR FT-IR spectroscopy, and DFT calculations. An influence of ionic strength on stability constants was detected, depending on the charge of the respective complexes. The conditional stability constants, determined for 1:1, 1:2, and 1:3 complexes at specific ionic strengths, were extrapolated to zero ionic strength. The interaction of the bacteria Sporomusa sp. MT-2.99 and Paenibacillus sp. MT-2.2 cells, isolated from Opalinus Clay, with Pu was studied. The experiments can be divided into such without an electron donor where biosorption is favored and such with addition of Na-pyruvate as an electron donor stimulating also bioreduction processes. Moreover, experiments were performed to study the interactions of the halophilic archaeon Halobacterium noricense DSM-15987 with U(VI), Eu(III), and Cm(III) in 3 M NaCl solutions. Research for improving process understanding with respect to the mobility of multivalent metals in systems containing humic matter was focused on the reversibility of elementary processes and on their interaction. Kinetic stabilization processes in the dynamics of humate complexation equilibria were quantified in isotope exchange studies. The influence of high salinity on the mobilizing potential of humic-like clay organics was systematically investigated and was described by modeling. The sorption of Tc(VII)/Tc(IV) onto the iron(II)-containing minerals magnetite and siderite was studied by means of batch sorption experiments, ATR FT-IR and X-ray absorption spectroscopy. The strong Tc

  20. The behaviour of radionuclides in soil

    International Nuclear Information System (INIS)

    Bunzl, K.

    1987-01-01

    Radionuclides in soil are of natural as well as of artificial origin. Their migration in the soil and their availability for ecological processes depend considerably on the extent at which they are sorbed. The methods for the determination of the vertical rate of migration are described. For most radionuclides this transport is very slow (a few cm per year). Cs-137 is of especial interest. It is sorbed strongly by most soils and, as a consequence, its root uptake is small. However, as a result of the sorption, this radionuclide is eluted from the root zone only very slowly and its thus available for the root uptake for many years. The Cs-137 concentrations in plants to be expected in the coming years as a result of the fallout from Chernobyl are small. (orig.) [de

  1. Radionuclides in ground-level air

    International Nuclear Information System (INIS)

    Sinkko, K.

    1987-01-01

    In the air surveillance programme the concentrations of artificial radionuclides are monitored in the air close to the ground to obtain the necessary basic data for estimating the exposure of the Finnish population to fall-out radionuclides and also to detect atmospheric traces of radioactive materials caused by their use or production. Airborne dust is collected on filters with high-volume air samplers and the concentrations of gamma-emitting radionuclides in the air are evaluated. In the first quarter of 1986 only long-lived cesium, caused by earlier atmospheric nuclear explosions was detected. The concentrations of cesium were very low. In January and March a small amount of short-lived, fresh fission and activation products were also observed

  2. Artificial Intelligence.

    Science.gov (United States)

    Information Technology Quarterly, 1985

    1985-01-01

    This issue of "Information Technology Quarterly" is devoted to the theme of "Artificial Intelligence." It contains two major articles: (1) Artificial Intelligence and Law" (D. Peter O'Neill and George D. Wood); (2) "Artificial Intelligence: A Long and Winding Road" (John J. Simon, Jr.). In addition, it contains two sidebars: (1) "Calculating and…

  3. Intelligence: Real or artificial?

    OpenAIRE

    Schlinger, Henry D.

    1992-01-01

    Throughout the history of the artificial intelligence movement, researchers have strived to create computers that could simulate general human intelligence. This paper argues that workers in artificial intelligence have failed to achieve this goal because they adopted the wrong model of human behavior and intelligence, namely a cognitive essentialist model with origins in the traditional philosophies of natural intelligence. An analysis of the word “intelligence” suggests that it originally r...

  4. National Low-Level Waste Management Program Radionuclide Report Series

    International Nuclear Information System (INIS)

    Rudin, M.J.; Garcia, R.S.

    1992-02-01

    This volume serves as an introduction to the National Low-Level Radioactive Waste Management Program Radionuclide Report Series. This report includes discussions of radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha-emitting transuranics with half-lives greater than five years). Each report includes information regarding radiological and chemical characteristics of specific radionuclides. Information is also included discussing waste streams and waste forms that may contain each radionuclide, and radionuclide behavior in the environment and in the human body. Not all radionuclides commonly found at low-level radioactive waste sites are included in this report. The discussion in this volume explains the rationale of the radionuclide selection process

  5. Microbial impact on the behavior of radionuclides in the environment. 1. Adsorption behavior of Pu(4) and Np(5) by bentonite under the influence of microbial reduction and siderophore

    International Nuclear Information System (INIS)

    Nagaoka, Toru; Watanabe, Yoshitomo; Kudo, Akira

    2002-01-01

    It is essential to understand the behavior of actinide in the environment to determine if the repositories can safely contain high-level radioactive waste. In the meantime, microbes contribute to the number of geochemical reactions in the subsurface environment, and some microorganisms can interact with actinides directly and/or indirectly (e.g., biotransformation, biosorption, bioaccumulation). From this point of view, we first investigated experimentally the microbial influence on the adsorption behavior of neptunium, which element is highly mobile in the environment because of the chemical form, NpO 2 + . With the cells (Desulfovibrio desulfaricans), Np in suspension was decreased to 5 % or less for 10 min, whereas the reductive adsorption by reducing agent Na 2 S, i.e., without cells, was much slower. This may show the microorganism reduce mobile Np(5) enzymatically to immobile Np(4). Secondly, we studied the effect of metal-chelator (Hydroxamate siderophore, Desferrioxamate B(DFOB)) on plutonium adsorption behavior. The Pu(4) adsorption decreased with increasing concentration of DFOB and reduced to almost 0 % at DFOB concentrations of 100 mM. However, at the low concentrations of DFOB and Pu (less than 1 x 10 -6 mol/l and 3.7 x 10 -11 mol/l respectively), there was little effect of DFOB on the adsorption of Pu. This result shows the DFOB effect on adsorption of Pu depends on the concentration of DFOB. At the low DFOB concentration, Pu would not chelate with DFOB because DFOB in the solution is not enough to form the complexes. DFOB actually dissolved impurities associated with bentonite, and the concentration of dissolved metal, e.g., Fe 3+ , was increasing with an increase of DFOB concentration in the suspension. These metal ions would compete with actinides, and the metal exchange may occur in a system with actinide-DFOB complexes. These results show that microorganisms can influence the behavior of actinides in the environment. Therefore, it is getting more

  6. Exposure-dose research for radionuclides in natural gas

    International Nuclear Information System (INIS)

    McNelis, D.N.; Patzer, R.G.

    1969-01-01

    The fate determination of specific radionuclides in natural gas stimulated by underground engineering applications is being examined. An experimental program, now in its initial stages, is using gas artificially labeled with krypton-85 and tritium under simulated domestic situations. The following topics are being investigated in this study: 1. The concentration of the radionuclides in a gas-heated home. 2. The build-up of contamination on appliances in the kitchen environment. 3. The concentration in foods as a function of radionuclide, food type and preparation. 4. The maximum exposure plausible under specified conditions. (author)

  7. Exposure-dose research for radionuclides in natural gas

    Energy Technology Data Exchange (ETDEWEB)

    McNelis, D N; Patzer, R G [Southwestern Radiological Health Laboratory, U.S. Public Health Service, Las Vegas, NV (United States)

    1969-07-01

    The fate determination of specific radionuclides in natural gas stimulated by underground engineering applications is being examined. An experimental program, now in its initial stages, is using gas artificially labeled with krypton-85 and tritium under simulated domestic situations. The following topics are being investigated in this study: 1. The concentration of the radionuclides in a gas-heated home. 2. The build-up of contamination on appliances in the kitchen environment. 3. The concentration in foods as a function of radionuclide, food type and preparation. 4. The maximum exposure plausible under specified conditions. (author)

  8. Quantitative radionuclide angiocardiography

    International Nuclear Information System (INIS)

    Scholz, P.M.; Rerych, S.K.; Moran, J.F.; Newman, G.E.; Douglas, J.M.; Sabiston, D.C. Jr.; Jones, R.H.

    1980-01-01

    This study introduces a new method for calculating actual left ventricular volumes and cardiac output from data recorded during a single transit of a radionuclide bolus through the heart, and describes in detail current radionuclide angiocardiography methodology. A group of 64 healthy adults with a wide age range were studied to define the normal range of hemodynamic parameters determined by the technique. Radionuclide angiocardiograms were performed in patients undergoing cardiac catherization to validate the measurements. In 33 patients studied by both techniques on the same day, a close correlation was documented for measurement of ejection fraction and end-diastolic volume. To validate the method of volumetric cardiac output calcuation, 33 simultaneous radionuclide and indocyanine green dye determinations of cardiac output were performed in 18 normal young adults. These independent comparisons of radionuclide measurements with two separate methods document that initial transit radionuclide angiocardiography accurately assesses left ventricular function

  9. Modeling the Effects of Cu Content and Deformation Variables on the High-Temperature Flow Behavior of Dilute Al-Fe-Si Alloys Using an Artificial Neural Network.

    Science.gov (United States)

    Shakiba, Mohammad; Parson, Nick; Chen, X-Grant

    2016-06-30

    The hot deformation behavior of Al-0.12Fe-0.1Si alloys with varied amounts of Cu (0.002-0.31 wt %) was investigated by uniaxial compression tests conducted at different temperatures (400 °C-550 °C) and strain rates (0.01-10 s -1 ). The results demonstrated that flow stress decreased with increasing deformation temperature and decreasing strain rate, while flow stress increased with increasing Cu content for all deformation conditions studied due to the solute drag effect. Based on the experimental data, an artificial neural network (ANN) model was developed to study the relationship between chemical composition, deformation variables and high-temperature flow behavior. A three-layer feed-forward back-propagation artificial neural network with 20 neurons in a hidden layer was established in this study. The input parameters were Cu content, temperature, strain rate and strain, while the flow stress was the output. The performance of the proposed model was evaluated using the K-fold cross-validation method. The results showed excellent generalization capability of the developed model. Sensitivity analysis indicated that the strain rate is the most important parameter, while the Cu content exhibited a modest but significant influence on the flow stress.

  10. Cyclic stress-strain behavior of polymeric nonwoven structures for the use as artificial leaflet material for transcatheter heart valve prostheses

    Directory of Open Access Journals (Sweden)

    Arbeiter Daniela

    2017-09-01

    Full Text Available Xenogenic leaflet material, bovine and porcine pericardium, is widely used for the fabrication of surgically implanted and transcatheter heart valve prostheses. As a biological material, long term durability of pericardium is limited due to calcification, degeneration and homogeneity. Therefore, polymeric materials represent a promising approach for a next generation of artificial heart valve leaflets with improved durability. Within the current study we analyzed the mechanical performance of polymeric structures based on elastomeric materials. Polymeric cast films were prepared and nonwovens were manufactured in an electrospinning process. Analysis of cyclic stress-strain behavior was performed, using a universal testing machine. The uniaxial cyclic tensile experiments of the elastomeric samples yielded a non-linear elastic response due to viscoelastic behavior with hysteresis. Equilibrium of stress-strain curves was found after a specific number of cycles, for cast films and nonwovens, respectively. In conclusion, preconditioning was found obligatory for the evaluation of the mechanical performance of polymeric materials for the use as artificial leaflet material for heart valve prostheses.

  11. Radionuclide evaluation of brain death

    International Nuclear Information System (INIS)

    Pjura, G.A.; Kim, E.E.

    1987-01-01

    The criteria employed for clinical determination of death have evolved in response to advances in life support and other medical technology. The technical feasibility of organ transplantation has amplified the need for a definition of brain death that can be applied in the shortest possible time in the presence of artificial maintenance of vegetative functions, including circulation. Radionuclide cerebral angiography is one of a group of diagnostic procedures that can be employed to confirm the clinical diagnosis of brain death through demonstration of absence of cerebral blood flow. The focus of this work is to assess its use as a confirmatory test for determination of brain death in the context of currently available alternative technologies

  12. Radionuclide diagnosis of vasculogenic impotence

    International Nuclear Information System (INIS)

    Sorokin, A.I.; Gerasimov, V.G.; Lenskaya, O.P.; Narkevich, B.Ya.; Bogdasarov, Yu.B.; Krotovskij, G.S.

    1988-01-01

    Pathogenesis of vasculogenic impotence is most adequately revealed by modern methods of the investigation of the hemodynamic mechanisms of erection with the enhancement of arterial perfusion of corpora cavernosa by artificial sexual stimulation. Radionuclide diagnostic methods effectively differ from the methods of radiocontrast phalloangiography by the simplicity of investigation and the absence of traumatism for a patient. The authors have proposed a mathematical model of a process of filling in the functioning volume of the penile vascular bed with a radiopharmaceutical prepation against the background of erection induced by intracavernous administration of papaverine hydrochloride solution. Parameters of the model determine the ratio of blood flow volumetric rates in the penis at rest and when erect

  13. The contamination of the oceans by anthropogenic radionuclides

    International Nuclear Information System (INIS)

    Figueira, Rubens C.L.; Cunha, Ieda I.L.

    1998-01-01

    Several hundreds of artificial of artificial radionuclides are produced as the result of human activities, such as the applications of nuclear reactors and particle accelerators, testing of nuclear weapons and nuclear accidents. Many of these radionuclides are short-lived and decay quickly after their production, but some of them are longer-lived and are released into the environment. From the radiological point of view the most important radionuclides are cesium-137, strontium-90 and plutonium-239, due to their chemical and nuclear characteristics. The two first radioisotopes present long half life (30 and 28 years), high fission yields and chemical behaviour similar to potassium and calcium, respectively. No stable element exists for plutonium-239, that presents high radiotoxity, longh half-life (24000 years) and some marine organisms accumulate plutonium at high levels. The radionuclides introduced into marine environment undergo various physical, chemical and biological processes taking place in the sea. These processes may be due to physical, dispersion or complicated chemical and biological interactions of the radionuclides with inorganic and organic suspend matter, variety of living organism, bottom sediments, etc. The behaviour of radionuclides in the sea depends primarily on their chemical properties, but it may also be influenced by properties of interacting matrices and other environmental factors. The major route of radiation exposure of man to artificial radionuclides occuring in the marine environment is through ingestion of radiologically contamined marine organisms. This paper summarizes the main sources of contamination in the marine environment and presents an overview covering the oceanic distribution of anthropogenic radionuclides in the FAO regions. A great number of measurements of artificial radioclides have been carried out on various marine environmental samples in different oceans over the world, being cesium-137 the most widely measured

  14. Marine biogeochemistry of radionuclides

    International Nuclear Information System (INIS)

    Fowler, S.W.

    1997-01-01

    Radionuclides entering the ocean from runoff, fallout, or deliberate release rapidly become involved in marine biogeochemical cycles. Sources, sinks and transport of radionuclides and analogue elements are discussed with emphasis placed on how these elements interact with marine organisms. Water, food and sediments are the source terms from which marine biota acquire radionuclides. Uptake from water occurs by surface adsorption, absorption across body surfaces, or a combination of both. Radionuclides ingested with food are either assimilated into tissue or excreted. The relative importance of the food and water pathway in uptake varies with the radionuclide and the conditions under which exposure occurs. Evidence suggests that, compared to the water and food pathways, bioavailability of sediment-bound radionuclides is low. Bioaccumulation processes are controlled by many environmental and intrinsic factors including exposure time, physical-chemical form of the radionuclide, salinity, temperature, competitive effects with other elements, organism size, physiology, life cycle and feeding habits. Once accumulated, radionuclides are transported actively by vertical and horizontal movements of organisms and passively by release of biogenic products, e.g., soluble excreta, feces, molts and eggs. Through feeding activities, particles containing radionuclides are ''packaged'' into larger aggregates which are redistributed upon release. Most radionuclides are not irreversibly bound to such particles but are remineralized as they sink and/or decompose. In the pelagic zones, sinking aggregates can further scavenge particle-reactive elements thus removing them from the surface layers and transporting them to depth. Evidence from both radiotracer experiments and in situ sediment trap studies is presented which illustrates the importance of biological scavenging in controlling the distribution of radionuclides in the water column. (author)

  15. Radionuclide release from PWR spent fuel specimens with induced cladding defects

    International Nuclear Information System (INIS)

    Wilson, C.N.; Oversby, V.M.

    1984-03-01

    Radionuclide releases from pressurized water reactor (PWR) spent fuel rod specimens containing various artificially induced cladding defects were compared by leach testing. The study was conducted in support of the Nevada Nuclear Waste Storage Investigations (NNWSI) Waste Package Task to evaluate the effectiveness of failed cladding as a barrier to radionuclide release. Test description and results are presented

  16. Radionuclide release from PWR spent fuel specimens with induced cladding defects

    International Nuclear Information System (INIS)

    Wilson, C.N.; Oversby, V.M.

    1984-03-01

    Radionuclide releases from pressurized water reactor (PWR) spent fuel rod specimens containing various artificially induced cladding defects were compared by leach testing. The study was conducted in support of the Nevada Nuclear Waste Storage Investigations (NNWSI) Waste Package Task to evaluate the effectiveness of failed cladding as a barrier to radionuclide release. Test description and results are presented. 6 references, 4 figures

  17. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Bocock, K.L.

    1981-01-01

    This report summarizes information on the distribution and movement of radionuclides in semi-natural terrestrial ecosystems in north-west England with particular emphasis on inputs to, and outputs from ecosystems; on plant and soil aspects; and on radionuclides in fallout and in discharges by the nuclear industry. (author)

  18. In-vivo evaluation of the kinematic behavior of an artificial medial meniscus implant: A pilot study using open-MRI.

    Science.gov (United States)

    De Coninck, Tineke; Elsner, Jonathan J; Linder-Ganz, Eran; Cromheecke, Michiel; Shemesh, Maoz; Huysse, Wouter; Verdonk, René; Verstraete, Koenraad; Verdonk, Peter

    2014-09-01

    In this pilot study we wanted to evaluate the kinematics of a knee implanted with an artificial polycarbonate-urethane meniscus device, designed for medial meniscus replacement. The static kinematic behavior of the implant was compared to the natural medial meniscus of the non-operated knee. A second goal was to evaluate the motion pattern, the radial displacement and the deformation of the meniscal implant. Three patients with a polycarbonate-urethane implant were included in this prospective study. An open-MRI was used to track the location of the implant during static weight-bearing conditions, within a range of motion of 0° to 120° knee flexion. Knee kinematics were evaluated by measuring the tibiofemoral contact points and femoral roll-back. Meniscus measurements (both natural and artificial) included anterior-posterior meniscal movement, radial displacement, and meniscal height. No difference (P>0.05) was demonstrated in femoral roll-back and tibiofemoral contact points during knee flexion between the implanted and the non-operated knees. Meniscal measurements showed no significant difference in radial displacement and meniscal height (P>0.05) at all flexion angles, in both the implanted and non-operated knees. A significant difference (P ≤ 0.05) in anterior-posterior movement during flexion was observed between the two groups. In this pilot study, the artificial polycarbonate-urethane implant, indicated for medial meniscus replacement, had no influence on femoral roll-back and tibiofemoral contact points, thus suggesting that the joint maintains its static kinematic properties after implantation. Radial displacement and meniscal height were not different, but anterior-posterior movement was slightly different between the implant and the normal meniscus. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Dynamic effects of tank waste aging on radionuclide-complexant interactions. 1998 annual progress report

    International Nuclear Information System (INIS)

    Arterburn, J.B.; Chamberlin, R.

    1998-01-01

    'The overall objective of this project is to provide a scientific basis for safely processing complexant-containing high-level tank wastes for disposal. The key goals are to identify a means to prepare realistic complexant-containing tank waste simulants, and to use those simulants to determine the relative importance of organic complexants and their breakdown products on the partitioning of important radionuclides. These goals will be accomplished by artificially aging complexant-containing tank waste simulants using microwave, ultrasound, and photolysis techniques. The simulants will be compared to samples of actual Hanford tank wastes to determine the most realistic aging method, on the basis of the organic fragmentation and the partitioning behavior of the important radionuclides 90 Sr, 99 Tc, and 239 Pu. Also, the authors will use their simulant aging process to investigate the relative effects of chelator degradation products on the partitioning of important radionuclides from the waste. Using NMR-active labels in the chelators, they will use a combinatorial approach of generating multiple chelator fragments in a single experiment and then determining which fragments have a negative effect on the separations chemistry. The successful completion of this goal will specifically identify the most problematic organic fragments in complexant-containing waste and provide the basis for developing successful treatment strategies for these wastes. This report summarizes work carried out at Los Alamos during the first 8 months of a 3-year project.'

  20. Monitoring and classifying animal behavior using ZigBee-based mobile ad hoc wireless sensor networks and artificial neural networks

    DEFF Research Database (Denmark)

    S. Nadimi, Esmaeil; Nyholm Jørgensen, Rasmus; Blanes-Vidal, Victoria

    2012-01-01

    Animal welfare is an issue of great importance in modern food production systems. Because animal behavior provides reliable information about animal health and welfare, recent research has aimed at designing monitoring systems capable of measuring behavioral parameters and transforming them...... into their corresponding behavioral modes. However, network unreliability and high-energy consumption have limited the applicability of those systems. In this study, a 2.4-GHz ZigBee-based mobile ad hoc wireless sensor network (MANET) that is able to overcome those problems is presented. The designed MANET showed high...... communication reliability, low energy consumption and low packet loss rate (14.8%) due to the deployment of modern communication protocols (e.g. multi-hop communication and handshaking protocol). The measured behavioral parameters were transformed into the corresponding behavioral modes using a multilayer...

  1. Artificial Consciousness or Artificial Intelligence

    OpenAIRE

    Spanache Florin

    2017-01-01

    Artificial intelligence is a tool designed by people for the gratification of their own creative ego, so we can not confuse conscience with intelligence and not even intelligence in its human representation with conscience. They are all different concepts and they have different uses. Philosophically, there are differences between autonomous people and automatic artificial intelligence. This is the difference between intelligence and artificial intelligence, autonomous versus a...

  2. Migration of radionuclides through a river system

    Energy Technology Data Exchange (ETDEWEB)

    Matsunaga, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-03-01

    Migration behavior of several atmospherically-derived radionuclides in a river watershed was studied. A main interest was in their relocation from the ground soil of the watershed to a downstream region through a river. Studied radionuclides are: {sup 137}Cs generated by weapon tests in the atmosphere; {sup 210}Pb and {sup 7}Be of naturally occurring radionuclides; {sup 137}Cs, {sup 90}Sr, {sup 239,240}Pu and {sup 241}Am released by the Chernobyl nuclear power plant accident. Dominance of the form in suspended solid in river water (particulate form) was qualified for the radionuclides in the Kuji river watershed. An importance of discharge in flooding was also confirmed. A historical budget analysis for weapon test derived {sup 137}Cs was presented for the Hi-i river watershed and its accompanied lake sediment (Lake Shinji). The work afforded a scheme of a fate of {sup 137}Cs after falling on the ground soil and on the lake surface. Several controlling factors, which can influence on the chemical form of radionuclides discharged to a river, were also investigated in the vicinity of the Chernobyl nuclear power plant. A special attention was paid on the association of the radionuclides with dissolved species in water. Preferential association of Pu and Am isotopes to a large molecular size of dissolved matrices, probably of humic substances, was suggested. (author)

  3. The effect of Nb addition on mechanical properties, corrosion behavior, and metal-ion release of ZrAlCuNi bulk metallic glasses in artificial body fluid.

    Science.gov (United States)

    Qiu, C L; Liu, L; Sun, M; Zhang, S M

    2005-12-15

    Bulk metallic glasses (BMGs) of Zr(65 - x)Nb(x)- Cu(17.5)Ni(10)Al(7.5) with Nb = 0, 2, and 5 at % were prepared by copper mold casting. Compression tests reveal that the two BMGs containing Nb exhibited superior strength and plasticity to the base alloy. The corrosion behavior of the alloys obtained was investigated in artificial body fluid by electrochemical measurements. It was found that the addition of Nb significantly enhanced the corrosion resistance of the Zr-based BMG, as indicated by a remarkable increase in corrosion potential and pitting potential. XPS analysis revealed that the passive film formed after anodic polarization was enriched in aluminum oxide and depleted in phosphate ions for the BMGs containing Nb, which accounts for the improvement of corrosion resistance. On the other hand, metal-ion release of different BMGs were determined in PPb (ng/mL) level with inductively coupled plasma mass spectrometry (ICP-MS) after being immersed in artificial body fluid at 37 degrees C for 20 days. It was found that the addition of Nb considerably reduced the ion release of all kinds of metals of the base system. This is probably attributed to the promoting effect of Nb on a rapid formation of highly protective film.

  4. The flow of radionuclides through the Canadian archipelago

    International Nuclear Information System (INIS)

    Ellis, K.; Smith, J.N.

    1999-01-01

    The transport of contaminants to the Canadian Arctic by air and in water and their concentration through the marine food web has lead to enhanced levels of contaminants in several foods of Canadian northern inhabitants. Artificial radionuclides in the marine water can be used to determine water circulation and to trace contaminant transport through the Canadian Archipelago

  5. 3. Production of radionuclides, preparation and handling of labelled compounds

    International Nuclear Information System (INIS)

    Toelgyessy, J.

    1981-01-01

    The preparation of natural radioactive compounds and the manufacture of artificial radionuclides, the labelling of organic compounds, and the methods of radioactive substance separation are described. The principles are shown of handling radioactive materials and a brief description is given of the stability, packaging and storage of radiopharmaceuticals. (J.P.)

  6. [Artificial organs].

    Science.gov (United States)

    Raguin, Thibaut; Dupret-Bories, Agnès; Debry, Christian

    2017-01-01

    Research has been fighting against organ failure and shortage of donations by supplying artificial organs for many years. With the raise of new technologies, tissue engineering and regenerative medicine, many organs can benefit of an artificial equivalent: thanks to retinal implants some blind people can visualize stimuli, an artificial heart can be proposed in case of cardiac failure while awaiting for a heart transplant, artificial larynx enables laryngectomy patients to an almost normal life, while the diabetic can get a glycemic self-regulation controlled by smartphones with an artificial device. Dialysis devices become portable, as well as the oxygenation systems for terminal respiratory failure. Bright prospects are being explored or might emerge in a near future. However, the retrospective assessment of putative side effects is not yet sufficient. Finally, the cost of these new devices is significant even if the advent of three dimensional printers may reduce it. © 2017 médecine/sciences – Inserm.

  7. Selected radionuclides important to low-level radioactive waste management

    International Nuclear Information System (INIS)

    1996-11-01

    The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). This report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237

  8. Selected radionuclides important to low-level radioactive waste management

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-01

    The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). This report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237.

  9. Process for encapsulating radionuclides

    International Nuclear Information System (INIS)

    Brownell, L.E.; Isaacson, R.E.

    1976-01-01

    Radionuclides are immobilized in virtually an insoluble form by reacting at a temperature of at least 90 0 C as an aqueous alkaline mixture having a solution pH of at least 10, containing a source of silicon, the radionuclide waste, and a metal cation. The molar ratio of silicon to the metal cation is on the order of unity to produce a gel from which complex metalosilicates crystallize to entrap the radionuclides within the resultant condensed crystal lattice. The product is a silicious stone-like material which is virtually insoluble and nonleachable in alkaline or neutral environment. One embodiment provides for the formation of the complex metalo-silicates, such as synthetic pollucite, by gel formation with subsequent calcination to the solid product; another embodiment utilizes a hydrothermal process, either above ground or deep within basalt caverns, at greater than atmospheric pressures and a temperature between 90 and 500 0 C to form complex metalo-silicates, such as strontium aluminosilicate. Another embodiment provides for the formation of complex metalo-silicates, such as synthetic pollucite, by slurrying an alkaline mixture of bentonite or kaolinite with a source of silicon and the radionuclide waste in salt form. In each of the embodiments a mobile system is achieved whereby the metalo-silicate constituents reorient into a condensed crystal lattice forming a cage structure with the condensed metalo-silicate lattice which completely surrounds the radionuclide and traps the radionuclide therein; thus rendering the radionuclide virtually insoluble

  10. Radionuclides in the oceans inputs and inventories

    International Nuclear Information System (INIS)

    Guegueniat, P.; Germain, P.; Metivier, H.

    1996-01-01

    Ten years after Chernobyl, following the decision by France to end nuclear weapon testing in the Pacific ocean, after the end of the OECD-NEA Coordinated Research and Environmental Surveillance programme related to low-level waste dumping in the deep ocean, and one hundred years after the discovery of radioactivity, the IPSN wanted to compile and review the available information on artificial radioactivity levels in seas and oceans. International experts have been invited to present data on inputs and inventories of radionuclides in the marine environment, and to describe the evolution of radioactivity levels in water, sediments and living organisms. Different sources of radionuclides present in the aquatic environment are described: atmospheric fallout before and after Chernobyl, industrial wastes, dumped wastes and ships, nuclear ship accidents, river inputs, earth-sea atmospheric transfers and experimental sites for nuclear testing. Radioactivity levels due to these sources are dealt with at ocean (Atlantic, Pacific and Indian) and sea level (Channel, North Sea, Irish Sea, Mediterranean, Baltic, Black Sea and Arctic seas). These data collected in the present book give an up-to-date assessment of radionuclide distributions which will be very useful to address scientific and wider public concerns about radionuclides found in the aquatic environment. It gives many references useful to those who want to deepen their understanding of particular aspects of marine radioecology. (authors)

  11. Foodstuffs, radionuclides, monitoring

    International Nuclear Information System (INIS)

    Denisikov, A.I.

    2000-01-01

    Radionuclide contamination of water and food stuffs as a result of the Chernobyl accident and permissible contents of 90 Sr and 137 Cs are considered in brief. A method of radiation monitoring of food stuffs and water for the radionuclides mentioned is suggested. The method permits employment of the simplest and cheapest radiometric equipment for analysis, whole the high degree of radionuclide concentration using fiber sorbents permits using the instrumentation without expensive shields against external radiation. A description of ion-exchange unit for radiation monitoring of liquid samples of food stuffs or water, is provided [ru

  12. Generator for radionuclide

    International Nuclear Information System (INIS)

    Weisner, P.S.; Forrest, T.R.F.

    1985-01-01

    This invention provides a radionuclide generator of the kind in which a parent radionuclide, adsorbed on a column of particulate material, generates a daughter radionuclide which is periodically removed from the column. This invention is particularly concerned with technetium generators using single collection vials. The generator comprises a column, a first reservoir for the eluent, a second reservoir to contain the volume of eluent required for a single elution, and means connecting the first reservoir to the second reservoir and the second reservoir to the column. Such a generator is particularly suitable for operation by vacuum elution

  13. {sup 137}Cs, {sup 90}Sr, {sup 241}Am and {sup 239+240}Pu radionuclides speciation in soils of the former Semipalatinsk test site

    Energy Technology Data Exchange (ETDEWEB)

    Kabdyrakova, A.M.; Kunduzbaeva, A.Y.; Lukashenko, S.N.; Magasheva, R.Y. [Institute of radiation safety and ecology (Kazakhstan)

    2014-07-01

    The paper presents results of studies into {sup 137}Cs and {sup 90}Sr, {sup 241}Am and {sup 239+240}Pu techno-genic radionuclides speciation in soils of ecosystems at different topography of the Semipalatinsk Test Site (STS), exposed to different nuclear testing. The data were obtained for radionuclides speciation in soils of the following STS ecosystems: - grassland ecosystems within near-portal areas of tunnels - horizontal adits constructed for nuclear testing, affected by radioactive-contaminated water flows from the tunnels of Degelen Site; - steppe ecosystems, exposed to ground radioactive contamination resulted from above-ground and aerial nuclear testing of different yield, as well as simulation (hydrodynamic and hydro-nuclear) experiments at 'Experimental Field' testing site. - steppe ecosystems, exposed to ground radioactive contamination caused by testing of liquid and powdery radiological warfare weapon (RWW) at Site '4 a'; - 'Northern' and 'Western' areas of STS, where concentration level of artificial radionuclides in soil is comparable with the level of global fall-outs ('background' areas). To study the radionuclides speciation, method of sequential extraction was applied, and water-soluble, exchange, organic mobile and tightly bound forms were separated. Feature of the studied grassland ecosystems is that they are developed solely along the bed of water streams flowing from tunnels and are located at small area of 1-2 m{sup 2}. Radioactive contamination of soil is caused by radioactive contaminant sorption by sediments. Despite the significant space limitation of the ecosystems content of radionuclides speciation in soil greatly varies, particularly readily-soluble and mobile forms. The variation may be explained by high humidity which makes possible both sorption and desorption processes. If basic radionuclides contributing to radioactive contamination of grassland soils at Degelen Site are {sup

  14. Intelligible Artificial Intelligence

    OpenAIRE

    Weld, Daniel S.; Bansal, Gagan

    2018-01-01

    Since Artificial Intelligence (AI) software uses techniques like deep lookahead search and stochastic optimization of huge neural networks to fit mammoth datasets, it often results in complex behavior that is difficult for people to understand. Yet organizations are deploying AI algorithms in many mission-critical settings. In order to trust their behavior, we must make it intelligible --- either by using inherently interpretable models or by developing methods for explaining otherwise overwh...

  15. Sources of anthropogenic radionuclides in the environment: a review

    International Nuclear Information System (INIS)

    Hu Qinhong; Weng Jianqing; Wang Jinsheng

    2010-01-01

    Studies of radionuclides in the environment have entered a new era with the renaissance of nuclear energy and associated fuel reprocessing, geological disposal of high-level nuclear wastes, and concerns about national security with respect to nuclear non-proliferation. This work presents an overview on sources of anthropogenic radionuclides in the environment, as well as a brief discussion of salient geochemical behavior of important radionuclides. We first discuss the following major anthropogenic sources and current developments that have lead, or could potentially contribute, to the radionuclide contamination of the environment: (1) nuclear weapons program; (2) nuclear weapons testing; (3) nuclear power plants; (4) uranium mining and milling; (5) commercial fuel reprocessing; (6) geological repository of high-level nuclear wastes that include radionuclides might be released in the future, and (7) nuclear accidents. Then, we briefly summarize the inventory of radionuclides 99 Tc and 129 I, as well as geochemical behavior for radionuclides 99 Tc, 129 I, and 237 Np, because of their complex geochemical behavior, long half-lives, and presumably high mobility in the environment; biogeochemical cycling and environment risk assessment must take into account speciation of these redox-sensitive radionuclides.

  16. Colloidal nature of radionuclides in seawater

    International Nuclear Information System (INIS)

    Feldman, I.

    1976-01-01

    There is considerable doubt that equilibrium calculations, i.e., employing solubility products and complex-ion stability constants, are valid for the submicro concentrations of radionuclides in seawater. The existence of radiocolloids should be expected in seawater. The great tendency of radiocolloids to adsorb onto finely-divided hydrous oxides makes their formation of significance in seawater, especially for artificial radionuclides. The subject of radiocolloid formation is reviewed in this chapter. It is shown that the 226 Ra/ 230 Th/U relationship found in seawater can be explained from the fact that the tendencies of these elements to form radiocolloids in seawater should decrease in order thorium > radium much greater than uranium. This explanation is much simpler than the prevailing oceanographic one. The theories for radiocolloid formation are discussed. The recent theory of Jones and Healy for the adsorption of hydrolyzable metal ions onto hydrous oxides is reviewed briefly, and its relevance to radiocolloid formation is pointed out

  17. Building Explainable Artificial Intelligence Systems

    National Research Council Canada - National Science Library

    Core, Mark G; Lane, H. Chad; van Lent, Michael; Gomboc, Dave; Solomon, Steve; Rosenberg, Milton

    2006-01-01

    As artificial intelligence (AI) systems and behavior models in military simulations become increasingly complex, it has been difficult for users to understand the activities of computer-controlled entities...

  18. Artificial intelligence

    CERN Document Server

    Ennals, J R

    1987-01-01

    Artificial Intelligence: State of the Art Report is a two-part report consisting of the invited papers and the analysis. The editor first gives an introduction to the invited papers before presenting each paper and the analysis, and then concludes with the list of references related to the study. The invited papers explore the various aspects of artificial intelligence. The analysis part assesses the major advances in artificial intelligence and provides a balanced analysis of the state of the art in this field. The Bibliography compiles the most important published material on the subject of

  19. Radionuclides in analytical chemistry

    International Nuclear Information System (INIS)

    Tousset, J.

    1984-01-01

    Applications of radionuclides in analytical chemistry are reviewed in this article: tracers, radioactive sources and activation analysis. Examples are given in all these fields and it is concluded that these methods should be used more widely [fr

  20. Radionuclide Basics: Iodine

    Science.gov (United States)

    ... Centers Radiation Protection Contact Us Share Radionuclide Basics: Iodine Iodine (chemical symbol I) is a chemical element. ... in the environment Iodine sources Iodine and health Iodine in the Environment All 37 isotopes of iodine ...

  1. Radioecological aspects in artificial groundwater recharge

    Energy Technology Data Exchange (ETDEWEB)

    Matthess, G [Kiel Univ. (Germany, F.R.). Geologisch-Palaeontologisches Inst. und Museum; Neumayr, V [Institut fuer Wasser-, Boden- und Lufthygiene, Frankfurt am Main (Germany, F.R.)

    1980-01-01

    In increasing extent surface waters, especially those of rivers and streams, are contaminated by radionuclides. Therefore it is necessary to investigate the possibility of impairment of the quality of artificially recharged groundwater and drinking water by radionuclides. Hazards for man are possible by drinking water, that was affected by waste and during exposition to air, as well as indirectly by irrigation water and the food chain. In a model calculation using realistic conditions the order of magnitude of these hazards for man by incorporation of radioactively contaminated artificially recharged drinking water are to be assessed. Here the parameters are discussed which must be considered in such an assessment. The model includes the use of river water for artificial recharge. All models and assessments assume the most unfavourable preconditions, which may lead to an impact to man.

  2. Abscess detection with radionuclides

    International Nuclear Information System (INIS)

    Alavi, J.B.

    1988-01-01

    Radionuclide studies may aid in the diagnosis and localization of intra-abdominal infections. Despite the introduction of new radiographic and ultrasound methods, there are several clinical situations in which radionuclide scans have proved useful. Those include detection of postoperative intra-abdominal abscess, evaluation of liver abscess, differentiation between pancreatic pseudocyst or abscess, evaluation of fever of unknown origin, and evaluation of inflammatory bowel disease. Each clinical situation is discussed separately here

  3. Effect of pH and fluoride on behavior of dental ZrO2 ceramics in artificial saliva

    International Nuclear Information System (INIS)

    Mukaeda, L.E.; Robin, A.; Santos, C.; Taguchi, S.P.; Borges Junior, L.A.

    2009-01-01

    A considerable increase in the ceramic products demand occurred due to the evolution of dental restoration techniques and these materials must resist to the complex mouth environment. The pH of saliva can decrease significantly due to the ingestion of acidic foods and beverages and mainly due to reactions occurring during bacteria metabolism that lead to the formation of organic acids. Fluorides are also present in the mouth since fluorides are usually added in drinking water, mouth washes, tooth pastes and gels for the prevention of plaque and caries formation. The combination of low pH and presence of fluorides can lead to the formation of HF and HF 2 - which are detrimental to metallic and probably to ceramic devices. In this work, commercial blocks of ZrO 2 ceramics (ProtMat Materiais Avancados® and Ivoclar®) were immersed in Fusayama artificial saliva of different pHs and fluoride concentrations. The properties of the as-produced ceramics (crystalline phases (XRD), microstructure (SEM), roughness (3D surface topography AFM) and mechanical resistance - Vickers hardness (Hv) and fracture toughness (KIC) were evaluated. Some of these properties were also determined after the immersion tests as well as the mass variation of the samples in order to evaluate the resistance of these ZrO 2 ceramics to degradation under these conditions. (author)

  4. Effect of pH and fluoride on behavior of dental ZrO{sub 2} ceramics in artificial saliva

    Energy Technology Data Exchange (ETDEWEB)

    Mukaeda, L.E.; Robin, A.; Santos, C.; Taguchi, S.P.; Borges Junior, L.A., E-mail: luizamukaeda@gmail.com, E-mail: alain@demar.eel.usp.br, E-mail: claudinei@demar.eel.usp.br, E-mail: simone@demar.eel.usp.br, E-mail: borges.jr@itelefonica.com.br [Universidade de Sao Paulo (EEL/DEMAR/USP), Lorena, SP (Brazil). Escola de Engenharia; Machado, J.P.B., E-mail: joaopaulo@las.inpe.br [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)

    2009-07-01

    A considerable increase in the ceramic products demand occurred due to the evolution of dental restoration techniques and these materials must resist to the complex mouth environment. The pH of saliva can decrease significantly due to the ingestion of acidic foods and beverages and mainly due to reactions occurring during bacteria metabolism that lead to the formation of organic acids. Fluorides are also present in the mouth since fluorides are usually added in drinking water, mouth washes, tooth pastes and gels for the prevention of plaque and caries formation. The combination of low pH and presence of fluorides can lead to the formation of HF and HF{sub 2}{sup -} which are detrimental to metallic and probably to ceramic devices. In this work, commercial blocks of ZrO{sub 2} ceramics (ProtMat Materiais Avancados® and Ivoclar®) were immersed in Fusayama artificial saliva of different pHs and fluoride concentrations. The properties of the as-produced ceramics (crystalline phases (XRD), microstructure (SEM), roughness (3D surface topography AFM) and mechanical resistance - Vickers hardness (Hv) and fracture toughness (KIC) were evaluated. Some of these properties were also determined after the immersion tests as well as the mass variation of the samples in order to evaluate the resistance of these ZrO{sub 2} ceramics to degradation under these conditions. (author)

  5. Radionuclides in drinking water: the recent legislative requirements of the European Union

    International Nuclear Information System (INIS)

    Grande, Sveva; Risica, Serena

    2015-01-01

    In November 2013, a new EURATOM Directive was issued on the protection of public health from the radionuclide content in drinking water. After introducing the contents of the Directive, the paper analyses the hypotheses about drinking water ingestion adopted in documents of international and national organizations and the data obtained from national/regional surveys. Starting from the Directive’s parametric value for the Indicative Dose, some examples of derived activity concentrations of radionuclides in drinking water are reported for some age classes and three exposure situations, namely, (i) artificial radionuclides due to routine water release from nuclear power facilities, (ii) artificial radionuclides from nuclear medicine procedures, and (iii) naturally occurring radionuclides in drinking water or resulting from existing or past NORM industrial activities. (paper)

  6. Biological accessibility of Chernobyl radionuclides and aspects of environmental rehabilitation

    International Nuclear Information System (INIS)

    Sokolik, G.A.; Leinova, S.L.; Ivanova, T.G.; Duksina, V.V.; Rubinchik, S.Ya.; Zaharenkov, V.V.

    1998-01-01

    The redistribution of 137 Cs, 90 Sr, 239,240 Pu and 241 Am within natural ecosystems and the determination of natural and artificial factors influencing on processes of radionuclide migration on biogeochemical chains were investigated. There are three main directions of investigation. The first of them is to estimate the intensity of self-purification of damaged region soil cover, taking into account landscape, soil, land-use differentiation and also peculiarities of physico-chemical occurrence forms of the radioactive fallout. In particular, the change dynamics of radionuclide physico-chemical state and vertical migration in soil of different genesis were estimated, the soil varieties with high and low rate of radionuclide migration were discovered, the peculiarities of 'hot' particles destruction, the change of their dispersity and structure composition under the influence of natural reagents were studied, the radionuclide bond strength with some components of different soil types was determined. The second problem is to estimate the biological accessibility of radionuclides. In particular, the radionuclide contamination of different components of forest and meadow phytocenoses was investigated, the change of radionuclide accumulation coefficients in system 'soil-plant' was estimated. The third problem is ecological and practice measures for environmental rehabilitation. In particular, the soil self-purification hypothesis in different natural conditions were created and the permissible criterion's of interference in natural processes were developed

  7. Near Real-Time Comprehension Classification with Artificial Neural Networks: Decoding e-Learner Non-Verbal Behavior

    Science.gov (United States)

    Holmes, Mike; Latham, Annabel; Crockett, Keeley; O'Shea, James D.

    2018-01-01

    Comprehension is an important cognitive state for learning. Human tutors recognize comprehension and non-comprehension states by interpreting learner non-verbal behavior (NVB). Experienced tutors adapt pedagogy, materials, and instruction to provide additional learning scaffold in the context of perceived learner comprehension. Near real-time…

  8. Artificial Reefs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An artificial reef is a human-made underwater structure, typically built to promote marine life in areas with a generally featureless bottom, control erosion, block...

  9. Microbiological Transformations of Radionuclides in the Subsurface

    International Nuclear Information System (INIS)

    Marshall, Matthew J.; Beliaev, Alex S.; Fredrickson, Jim K.

    2010-01-01

    Microorganisms are ubiquitous in subsurface environments although their populations sizes and metabolic activities can vary considerably depending on energy and nutrient inputs. As a result of their metabolic activities and the chemical properties of their cell surfaces and the exopolymers they produce, microorganisms can directly or indirectly facilitate the biotransformation of radionuclides, thus altering their solubility and overall fate and transport in the environment. Although biosorption to cell surfaces and exopolymers can be an important factor modifying the solubility of some radionuclides under specific conditions, oxidation state is often considered the single most important factor controlling their speciation and, therefore, environmental behavior.

  10. Natural - synthetic - artificial!

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2010-01-01

    The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

  11. Radionuclides in corals of Costa Rica

    International Nuclear Information System (INIS)

    Loria M, L.G.; Banichevich, A.; Cortes, T.

    1998-01-01

    Using Low Level Spectrometry they have evaluated the activity (Kq/kg) of 40 K, the gamma emisor daugther of 238 U and 232 Th and the presence of arificial isotopes due to anthropogenic contamination. The probes used are coral as biodynamic captors. The results show a presence between low and mittel of natural isotopes compared to other accumulation processes like sedimentation in soil and agricultural production. The Caribbean side show a higher activity than the Pacific for 40 K and a similar for 226 Ra. Results show low activity for artificial radionuclides with short lif ( 137 Cs). (author) [es

  12. A study on elongation/contraction behavior and mechanical properties of oxy-polyacrylonitrile(PAN) fiber in basic/acidic solution for artificial muscle applications

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y.K.; Kim, S.W.; Lee, K.S.; Cho, I.H.; Lee, J.H.; Lee, J.W. [Sungkyunkwan University, Suwon (Korea); Kim, K.J. [University of Nevada, Reno (United States); Nam, J.D. [Sungkyunkwan University, Suwon (Korea)

    2002-07-01

    Oxy-PAN fiber prepared from the preoxidation and saponification of raw PAN fiber is known to elongate and contract when immersed in basic and acidic solutions, respectively. In this study, about 30% elongation in NaOH solution and 30{approx}50% contraction in HCl solution have been observed. In mechanical test, the mechanical properties of oxy-PAN fiber in the contracted state was stronger than that in the elongated state. These behaviors and mechanical properties are compared to those of living muscle and linear actuator. The change of length in NaOH and HCl solutions is due to switching between a hydrophilic and a hydrophobic structure. Other reasons are exchange of ion and water in/out of oxy-PAN fiber, and osmotic pressure difference associated with relevant ions. Much studies are needed to clarify the effective factors on but the oxy-PAN fiber's elongation/contraction behavior and mechanical properties, but the oxy-PAN fiber prepared in our laboratory has a sufficient potential for application as artificial muscle and linear actuator. (author). 20 refs., 1 tab., 9 figs.

  13. The fate and importance of radionuclides produced in nuclear events

    Energy Technology Data Exchange (ETDEWEB)

    Shore, B; Anspaugh, L; Chertok, R; Gofman, J; Harrison, F; Heft, R; Koranda, J; Ng, Y; Phelps, P; Potter, G; Tamplin, A [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1969-07-01

    Some of the major program at the Bio-Medical Division concerned with the fate and importance of the fission products, the radionuclides induced in the device materials, the radionuclides induced in the environment surrounding the device, and the tritium produced in Plowshare cratering events will be discussed. These programs include (1) critical unknowns in predicting organ and body burdens from radionuclides produced in cratering events; (2) the analysis with a high-resolution solid state gamma ray spectrometer of radionuclides in complex biological and environmental samples; (3) the characterization of radioactive particles from cratering detonation; (4) the biological availability to beagles, pigs and goats of radionuclides in Plowshare debris; (5) the biological availability to aquatic animals of radionuclides in Plowshare and other nuclear debris and the biological turnover of critical nuclides in specific aquatic animals; (6) the biological availability of Plowshare and other nuclear debris radionuclides to dairy cows and the transplacental transport of debris radionuclides in the dairy cow; (7) the persistence and behavior of radionuclides, particularly tritium, at sites of Plowshare and other nuclear detonations; and (8) somatic effects of Low Dose Radiation: Chromosome studies. (author)

  14. Radionuclide transfer onto ground surface in surface water flow, 1

    International Nuclear Information System (INIS)

    Mukai, Masayuki; Takebe, Shinichi; Komiya, Tomokazu; Kamiyama, Hideo

    1991-07-01

    Radionuclides migration in ground surface water flow is considered to be one of the important path way in the scenario for environmental migration of radionuclides leaked from low level radioactive waste repository. Simulating the slightly sloped surface on which contaminated solution is flowing downward, testing for radionuclide migration on ground surface had been started. As it's first step, an experiment was carried out under the condition of restricted infiltration in order to elucidate the adsorption behavior of radionuclides onto the loamy soil surface in related with hydraulic conditions. Radionuclides concentration change in effluent solution with time and a concentration distribution of radionuclides adsorbed on the ground surface were obtained from several experimental conditions combining the rate and the duration time of the water flow. The radionuclides concentration in the effluent solution was nearly constant during each experimental period, and was reduced under the condition of lower flow rate. The surface distribution of radionuclides concentration showed two distinctive regions. The one was near the inlet vessel where the concentration was promptly reducing, and the other was following the former where the concentration was nearly constant. The characteristic surface distribution of radionuclides concentration can be explained by a two dimensional diffusion model with a first order adsorption reaction, based on the advection of flow rate distribution in perpendicular direction. (author)

  15. The fate and importance of radionuclides produced in nuclear events

    International Nuclear Information System (INIS)

    Shore, B.; Anspaugh, L.; Chertok, R.; Gofman, J.; Harrison, F.; Heft, R.; Koranda, J.; Ng, Y.; Phelps, P.; Potter, G.; Tamplin, A.

    1969-01-01

    Some of the major program at the Bio-Medical Division concerned with the fate and importance of the fission products, the radionuclides induced in the device materials, the radionuclides induced in the environment surrounding the device, and the tritium produced in Plowshare cratering events will be discussed. These programs include (1) critical unknowns in predicting organ and body burdens from radionuclides produced in cratering events; (2) the analysis with a high-resolution solid state gamma ray spectrometer of radionuclides in complex biological and environmental samples; (3) the characterization of radioactive particles from cratering detonation; (4) the biological availability to beagles, pigs and goats of radionuclides in Plowshare debris; (5) the biological availability to aquatic animals of radionuclides in Plowshare and other nuclear debris and the biological turnover of critical nuclides in specific aquatic animals; (6) the biological availability of Plowshare and other nuclear debris radionuclides to dairy cows and the transplacental transport of debris radionuclides in the dairy cow; (7) the persistence and behavior of radionuclides, particularly tritium, at sites of Plowshare and other nuclear detonations; and (8) somatic effects of Low Dose Radiation: Chromosome studies. (author)

  16. Radionuclides concentration in foods in Peninsular Malaysia

    International Nuclear Information System (INIS)

    Zalina Laili; Muhamat Omar; Mohd Nahar Othman; Md Suhaimi Elias; Esther Philip, Mohd Zaidi Ibrahim; Faizal Azrin Abdul Razalim; Azmi Hassan

    2006-01-01

    The concentrations of natural radionuclides (U-238, Th-232, Ra-226, Ra-228 and K-40) and artificial radionuclides (Cs-137) in fresh, dried and cooked foodstuffs from 30 major towns in Peninsular Malaysia were determined by gamma spectrometry system and Instrumental Neutron Activation Analysis (INAA) technique. A total of 232 samples representing a typical Malaysian community diet were analysed. The results showed that most of the samples contained only natural radionuclides. The percentage of radionuclides detected in the samples were found about 2% for U-238, 9% for Th-232, 49% for Ra-226, 77% for Ra-228, 99% for K-40 and 15% for Cs-137. The radionuclide concentrations were in the ranges of <6.1 - 29.3, <2.0 - 55.8, <0.1 - 34.4, <0.1 - 41, <0.1- 2552.3 and < 0.1 - 6.6 Bq/Kg dry weight for U-238, Th-232, Ra-226, Ra-228 and K-40 and Cs-137 respectively. The study revealed that most of the foodstuffs did not contain U-238. Lentils were found to contain significant concentration of Th-232 (4 - 49 Bq/kg) and can be considered as thorium accumulators. The concentrations of Ra-226 and Ra-228 in leafy vegetables were higher than the fruit and root vegetables. These data can be used as a reference for future food radioactivity monitoring. As edible mushroom and fern had high concentrations of Cs-137, indicating their high ability to accumulate Cs-137, they could be used as indicator plants in the event of radioactive fall outs

  17. Mass spectrometry of long-lived radionuclides

    International Nuclear Information System (INIS)

    Becker, Johanna Sabine.

    2003-01-01

    The capability of determining element concentrations at the trace and ultratrace level and isotope ratios is a main feature of inorganic mass spectrometry. The precise and accurate determination of isotope ratios of long-lived natural and artificial radionuclides is required, e.g. for their environmental monitoring and health control, for studying radionuclide migration, for age dating, for determining isotope ratios of radiogenic elements in the nuclear industry, for quality assurance and determination of the burn-up of fuel material in a nuclear power plant, for reprocessing plants, nuclear material accounting and radioactive waste control. Inorganic mass spectrometry, especially inductively coupled plasma mass spectrometry (ICP-MS) as the most important inorganic mass spectrometric technique today, possesses excellent sensitivity, precision and good accuracy for isotope ratio measurements and practically no restriction with respect to the ionization potential of the element investigated--therefore, thermal ionization mass spectrometry (TIMS), which has been used as the dominant analytical technique for precise isotope ratio measurements of long-lived radionuclides for many decades, is being replaced increasingly by ICP-MS. In the last few years instrumental progress in improving figures of merit for the determination of isotope ratio measurements of long-lived radionuclides in ICP-MS has been achieved by the application of a multiple ion collector device (MC-ICP-MS) and the introduction of the collision cell interface in order to dissociate disturbing argon-based molecular ions, to reduce the kinetic energy of ions and neutralize the disturbing noble gas ions (e.g. of 129 Xe + for the determination of 129 I). The review describes the state of the art and the progress of different inorganic mass spectrometric techniques such as ICP-MS, laser ablation ICP-MS vs. TIMS, glow discharge mass spectrometry, secondary ion mass spectrometry, resonance ionization mass

  18. Radionuclide sources in the Barents and Kara Seas

    International Nuclear Information System (INIS)

    Smith, J.N.; Ellis, K.M.; Forman, S.; Polyak, L.; Ivanov, G.; Matishov, D.; Kilius, L.

    1995-01-01

    A study of radionuclide distributions in the Barents Sea sediments was carried out in 1992. The conclusions of the study are as follows: 1) Elevated levels of artificial radionuclides as great as 15,000 Bq/kg for 239,240 Pu, 250 Bq/kg for 137 Cs and 100 Bq/kg for 60 Co were measured in sediments in Chermaya Bay which have been contaminated by several nuclear tests conducted in the 1950s. 2) Sediment-depth distributions of 239,240 Pu and other artificial radionuclides are consistent with results from biodiffusion models that are constrained by 210 Pb sediment-depth distributions. These results indicate that sedimentation rates in Chernaya Bay are low ( 249 Pu/ 239 Pu and 241 Pu/ 239 Pu atom ratios of 0.030 and 0.0012, respectively and a 241 Am/ 239,240 Pu activity ratio of 0.05 (compared to 0.3 in fallout) which provides a method for tracking its dispersion over distances of 100 km into the Barents Sea. 4) Artificial radionuclide levels in sediments and seawater near a sunken barge loaded with radioactive wastes in the Novaya Zemlya trough are similar to background fallout levels in the Kara Sea and provide little evidence for the release of radioactive contaminants from the dumpsite. 7 refs., 4 figs

  19. Studies on the Biotribological and Biological Behavior of Thermally Oxidized Ti6Al4V for Use in Artificial Cervical Disk

    Science.gov (United States)

    Wang, Song; Li, Junhui; Lu, Junzhe; Tyagi, Rajnesh; Liao, Zhenhua; Feng, Pingfa; Liu, Weiqiang

    2017-05-01

    The artificial cervical disk was simplified and considered as a ball-on-socket model with the material configuration of ultra-high molecular weight polyethylene and Ti6Al4V (PE-on-TC4). In order to improve the wear resistance, an optimized thermal oxidation (TO) coating was applied on TC4 component. The long-term wear behavior of the model was assessed in vitro using a wear simulator under 10 million cycles (MC) testing intervals. The biological behavior was investigated by bone marrow-derived mesenchymal stem cells (BMSCs) cell attachment and cell viability/proliferation assays, respectively. The total average wear rate for PE/TC4 pair was found to be 0.81 mg/MC, whereas the same was about 0.96 mg/MC for PE/TO pair. The wear rate of the metal has been neglected in comparison with that of the mating polymer. PE component was found to suffer severe damage characterized by scratches, fatigue cracks and arc-shaped wear grooves on the edge zone of ball. The dominant wear mechanism was abrasion for metal component while the dominant failure mechanism was a mix of plowing, fatigue and plastic deformation for polymer component. TO coating improved the cell attachment property of TC4, and the cell viability results were also quite good. TO coating protected TC4 from being plowed and avoided the release of toxic metal ions. However, this intensified the wear of PE component. Considering the biotribological and biological behavior in totality, TO coating could still be promising when applied in articulation surfaces.

  20. Radioactivity: radionuclides in foods

    International Nuclear Information System (INIS)

    Simpson, R.E.; Baratta, E.J.; Jelinek, C.F.

    1977-01-01

    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

  1. Modeling of High Temperature Oxidation Behavior of FeCrAl Alloy by using Artificial Neural Network

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Joon; Ryu, Ho Jin [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    Refractory alloys are candidate materials for replacing current zirconium-base cladding of light water reactors and they retain significant creep resistance and mechanical strength at high temperatures up to 1500 ℃ due to their high melting temperature. Thermal neutron cross sections of refractory metals are higher than that of zirconium, however the loss of neutron can be overcome by reducing cladding thickness which can be facilitated with enhanced mechanical properties. However, most refractory metals show the poor oxidation resistance at a high temperature. Oxidation behaviors of the various compositions of FeCrAl alloys in high temperature conditions were modeled by using Bayesian neural network. The automatic relevance determination (ARD) technique represented the influence of the composition of alloying elements on the oxidation resistance of FeCrAl alloys. This model can be utilized to understand the tendency of oxidation behavior along the composition of each element and prove the applicability of neural network modeling for the development of new cladding material of light water reactors.

  2. The Geochemistry of Technetium: A Summary of the Behavior of an Artificial Element in the Natural Environment

    Energy Technology Data Exchange (ETDEWEB)

    Icenhower, Jonathan P.; Qafoku, Nikolla; Martin, Wayne J.; Zachara, John M.

    2008-12-01

    Interest in the chemistry of technetium has only increased since its discovery in 1937, mainly because of the large and growing inventory of 99Tc generated during fission of 235U, its environmental mobility in oxidizing conditions, and its potential radiotoxicity. For every ton of enriched uranium fuel (3% 235U) that is consumed at a typical burn-up rate, nearly 1 kg of 99Tc is generated. Thus, the mass of 99Tc produced since 1993 has nearly quadrupled, and will likely to continue to increase if more emphasis is placed on nuclear power to slow the accumulation of atmospheric greenhouse gases. In order to gain a comprehensive understanding of the interaction of 99Tc and the natural environment, we review the sources of 99Tc in the nuclear fuel cycle, its chemical properties, radiochemistry, and biogeochemical behavior. We include an evaluation of the use of Re as a chemical analog of Tc, as well as a summary of the redox potential, thermodynamics, sorption, colloidal behavior, and interaction of humic substances with Tc, and the potential for re-oxidation and remobilization of Tc(IV). What emerges is a more complicated picture of Tc behavior than that of an easily tractable transition of Tc(VII) to Tc(IV) with consequent immobilization. Reducing conditions (+200 to +100 mV Eh) are generally thought necessary to cause reduction of Tc(VII) to Tc(IV), but far more important are the presence of reducing agents, such as Fe(II) sorbed onto mineral grains. Catalysis of Tc(VII) by surface-mediated Fe(II) will bring the mobile Tc(VII) species to a lower oxidation state and will form the relatively insoluble Tc(IV)O2∙nH2O, but even as a solid, equilibrium concentrations of aqueous Tc are nearly a factor of 20× above the EPA set drinking water standards. However, sequestration of Tc(IV) into Fe(III)-bearing phases, such as goethite or other hydrous oxyhydroxides of iron, may ameliorate concerns over the mobility of Tc. Further, the outcome of many studies on terrestrial and

  3. Artificial sweeteners

    DEFF Research Database (Denmark)

    Raben, Anne Birgitte; Richelsen, Bjørn

    2012-01-01

    Artificial sweeteners can be a helpful tool to reduce energy intake and body weight and thereby risk for diabetes and cardiovascular diseases (CVD). Considering the prevailing diabesity (obesity and diabetes) epidemic, this can, therefore, be an important alternative to natural, calorie-containin......Artificial sweeteners can be a helpful tool to reduce energy intake and body weight and thereby risk for diabetes and cardiovascular diseases (CVD). Considering the prevailing diabesity (obesity and diabetes) epidemic, this can, therefore, be an important alternative to natural, calorie......-containing sweeteners. The purpose of this review is to summarize the current evidence on the effect of artificial sweeteners on body weight, appetite, and risk markers for diabetes and CVD in humans....

  4. Radionuclides in house dust

    CERN Document Server

    Fry, F A; Green, N; Hammond, D J

    1985-01-01

    Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, alt...

  5. Radionuclides in the ecological system of the Boka Kotorska Bay

    International Nuclear Information System (INIS)

    Martic, M.; Ajdacic, N.

    1988-01-01

    In order to determine radioactive contamination in the South Adriatic region after May, 1986, activities of 21 radionuclides of natural and artificial origin were determined by gamma-spectrometry in the samples of sea water, sediments and several characteristic types of organisms collected on several locations in the Boka Kotorska Bay and open sea. Quantitative data on radionuclide contents are presented. Change of activity levels with respect to the 'zero state' determined for this region during previous years is also discussed. (author) 6 refs.; 4 tabs

  6. Concentration and speciation of radionuclides in environmental samples

    International Nuclear Information System (INIS)

    Testa, C.; Desideri, D.; Meli, M.A.; Roselli, C.

    2000-01-01

    The paper will describe three examples dealing with the measure of some natural (U, Th, 2 10Pb, 4 0K) and artificial ( 1 37Cs, 9 0Sr, 2 39 +2 40Pu, 2 41Am) radionuclides in environmental samples such as mosses, sediments, soils. Extraction chromatography, liquid extraction, selective precipitation and electroplating were used to isolate the radionuclides, except for gamma emitters which were detected by gamma spectrometry. Alpha spectrometry were used to measure the alpha emitters and low background beta detector to measure the beta emitters

  7. Intercomparison of radionuclide measurements in marine sediment sample IAEA-367

    International Nuclear Information System (INIS)

    Ballestra, S.; Lopez, J.J.; Gastaud, J.; Vas, D.; Noshkin, V.

    1991-08-01

    The results of an intercomparison exercise on a Pacific Ocean sediment sample, IAEA-367, designed for the determination of artificial and natural radionuclides levels, are reported. The data from 81 laboratories representing 37 countries have been evaluated. The following are the recommended values, with confidence intervals, for 60 Co, 90 Sr, 137 Cs, 239+240 Pu (Reference date: 1 January 1990). Information values for 155 Eu, 238 Pu, 241 Am, and 241 Pu are reported. Information values for the following natural radionuclides 40 K, 226 Ra, 228 Th, 230 Th, 234 U, 235 U and 238 U are also reported. (author)

  8. Artificial Intelligence

    CERN Document Server

    Warwick, Kevin

    2011-01-01

    if AI is outside your field, or you know something of the subject and would like to know more then Artificial Intelligence: The Basics is a brilliant primer.' - Nick Smith, Engineering and Technology Magazine November 2011 Artificial Intelligence: The Basics is a concise and cutting-edge introduction to the fast moving world of AI. The author Kevin Warwick, a pioneer in the field, examines issues of what it means to be man or machine and looks at advances in robotics which have blurred the boundaries. Topics covered include: how intelligence can be defined whether machines can 'think' sensory

  9. Artificial intelligence

    International Nuclear Information System (INIS)

    Perret-Galix, D.

    1992-01-01

    A vivid example of the growing need for frontier physics experiments to make use of frontier technology is in the field of artificial intelligence and related themes. This was reflected in the second international workshop on 'Software Engineering, Artificial Intelligence and Expert Systems in High Energy and Nuclear Physics' which took place from 13-18 January at France Telecom's Agelonde site at La Londe des Maures, Provence. It was the second in a series, the first having been held at Lyon in 1990

  10. Targeted Radionuclide Therapy

    Directory of Open Access Journals (Sweden)

    David Cheng

    2011-10-01

    Full Text Available Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose.

  11. Targeted Radionuclide Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ersahin, Devrim, E-mail: devrimersahin@yahoo.com; Doddamane, Indukala; Cheng, David [Department of Diagnostic Radiology, School of Medicine, Yale University, 333 Cedar St., New Haven, CT 06520 (United States)

    2011-10-11

    Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose.

  12. Radionuclide deposition control

    International Nuclear Information System (INIS)

    1980-01-01

    A method is described for controlling the deposition, on to the surfaces of reactor components, of the radionuclides manganese-54, cobalt-58 and cobalt-60 from a liquid stream containing the radionuclides. The method consists of disposing a getter material (nickel) in the liquid stream, and a non-getter material (tantalum, tungsten or molybdenum) as a coating on the surfaces where deposition is not desired. The process is described with special reference to its use in the coolant circuit in sodium cooled fast breeder reactors. (U.K.)

  13. Radionuclide examination in rheumatology

    International Nuclear Information System (INIS)

    Streda, A.; Kolar, J.; Valesova, M.

    1984-01-01

    On the basis of twenty years of experience with the use of radionuclides in bone and articular rheumatic diseases indications for such examinations are summed up. The main advantage of the use of radionuclide methods is that they bring forward early diagnosis of tissue reconstruction which can thus be detected at the stage of microstructural changes. They also provide earlier and more reliable detection of the degree of the pathological process than is provided by X-ray examination. In some cases scintiscan may also be found useful as a method for following up the results of treatment of rheumatic diseases. (author)

  14. Targeted Radionuclide Therapy

    International Nuclear Information System (INIS)

    Ersahin, Devrim; Doddamane, Indukala; Cheng, David

    2011-01-01

    Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose

  15. Transfer parameters of radionuclides in the marine environment

    International Nuclear Information System (INIS)

    1996-03-01

    To increase the accuracy of estimation of exposure dose by radionuclides in the marine, the informations of environmental parameter data in the marine were collected, arranged and discussed. The informations were discussed by 'a sectional committee of marine suspended solids and sediment'. The following problems were investigated and the studies were recorded in this report, clear explanation about the distribution factor (kd), the estimation method of kd, the fluctuating factor of kd data (properties of suspension and sediment, differences among the experimental methods), the physical and chemical behavior of radionuclides, sediment of radionuclides by means of sorption to the suspended particles in the marine, sorption of radionuclides into the marine soil (sediment), re-eluent of radionuclides sorpted in the marine soil (sediment), and relation between marine organism and marine suspended materials and sediment. (S.Y.)

  16. Chemical fractionation of radionuclides and stable elements in aquatic plants of the Yenisei River.

    Science.gov (United States)

    Bolsunovsky, Alexander

    2011-09-01

    The Yenisei River is contaminated with artificial radionuclides released by one of the Russian nuclear plants. The aquatic plants growing in the radioactively contaminated parts of the river contain artificial radionuclides. The aim of the study was to investigate accumulation of artificial radionuclides and stable elements by submerged plants of the Yenisei River and estimate the strength of their binding to plant biomass by using a new sequential extraction scheme. The aquatic plants sampled were: Potamogeton lucens, Fontinalis antipyretica, and Batrachium kauffmanii. Gamma-spectrometric analysis of the samples of aquatic plants has revealed more than 20 radionuclides. We also investigated the chemical fractionation of radionuclides and stable elements in the biomass and rated radionuclides and stable elements based on their distribution in biomass. The greatest number of radionuclides strongly bound to biomass cell structures was found for Potamogeton lucens and the smallest for Batrachium kauffmanii. For Fontinalis antipyretica, the number of distribution patterns that were similar for both radioactive isotopes and their stable counterparts was greater than for the other studied species. The transuranic elements (239)Np and (241)Am were found in the intracellular fraction of the biomass, and this suggested their active accumulation by the plants.

  17. Natural and Artificial Radioactivity in Drinkingwater in Malaga, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, M. C.; Duenas, C.; Gordo, E.; Canete, S. [Department of Applied Physics I, Faculty of Science, University of Malaga (Spain); Perez, M. [Department of Radiology and Health Physics, Faculty of Medicine, University of Malaga, Malaga (Spain)

    2013-07-15

    The measurement of radioactivity in drinking water permits us to determine the exposure of the population to radiation from the habitual consumption of water. An intensive study of the water supply in the city of Malaga during 2002-2010 has been carried out in order to determine the gross alpha and gross beta activities and natural and artificial radionuclides present in drinking water. A database on natural and artificial radioactivity in water was created. The results indicated that a high percentage of the water sample contains a total gross alpha and beta concentration of less than 0.10 Bq/L and 1 Bq/L, respectively. The main objectives were: (1) to analyse gross alpha and gross beta activities and to know the statistical distributions; (2) to study the levels of natural and artificial radionuclides; (3) to determine a possible mathematical correlation between the radionuclides and several factors. (author)

  18. Artificial Intelligence.

    Science.gov (United States)

    Wash, Darrel Patrick

    1989-01-01

    Making a machine seem intelligent is not easy. As a consequence, demand has been rising for computer professionals skilled in artificial intelligence and is likely to continue to go up. These workers develop expert systems and solve the mysteries of machine vision, natural language processing, and neural networks. (Editor)

  19. Boosting the Recoverable Energy Density of Lead-Free Ferroelectric Ceramic Thick Films through Artificially Induced Quasi-Relaxor Behavior.

    Science.gov (United States)

    Peddigari, Mahesh; Palneedi, Haribabu; Hwang, Geon-Tae; Lim, Kyung Won; Kim, Ga-Yeon; Jeong, Dae-Yong; Ryu, Jungho

    2018-06-08

    Dielectric ceramic film capacitors, which store energy in the form of electric polarization, are promising for miniature pulsed power electronic device applications. For a superior energy storage performance of the capacitors, large recoverable energy density, along with high efficiency, high power density, fast charge/discharge rate, and good thermal/fatigue stability, is desired. Herein, we present highly dense lead-free 0.942[Na 0.535 K 0.480 NbO 3 ]-0.058LiNbO 3 (KNNLN) ferroelectric ceramic thick films (∼5 μm) demonstrating remarkable energy storage performance. The nanocrystalline KNNLN thick film fabricated by aerosol deposition (AD) process and annealed at 600 °C displayed a quasi-relaxor ferroelectric behavior, which is in contrast to the typical ferroelectric nature of the KNNLN ceramic in its bulk form. The AD film exhibited a large recoverable energy density of 23.4 J/cm 3 , with an efficiency of over 70% under the electric field of 1400 kV/cm. Besides, an ultrahigh power density of 38.8 MW/cm 3 together with a fast discharge speed of 0.45 μs, good fatigue endurance (up to 10 6 cycles), and thermal stability in a wide temperature range of 20-160 °C was also observed. Using the AD process, we could make a highly dense microstructure of the film containing nano-sized grains, which gave rise to the quasi-relaxor ferroelectric characteristics and the remarkable energy storage properties.

  20. Taking radionuclides to heart

    International Nuclear Information System (INIS)

    Kleynhans, P.H.T.; Lotter, M.G.; Van Aswegen, A.; Minnaar, P.C.; Iturralde, M.; Herbst, C.P.; Marx, D.

    1980-01-01

    Ischaemic heart disease is a main cause of death in South Africa. Non-invasive ECG gated radionuclide bloodpool imaging plays an increasingly useful role in the evalution of the function of the heart as a pump, and the extent of heart muscle perfusion defects is further pinpointed by invasive krypton-81m studies to improve patient management

  1. Soil burden by radionuclides

    International Nuclear Information System (INIS)

    Blum, W.E.H.; Wenzel, W.W.

    1989-01-01

    Natural radioactivity - half-lifes and radiation type of man-made nuclides, radionuclide behaviour in soils, effects on soil condition and soil functions are described. The only mode of decontamination is by decay and thus primarily dependent on the half-life of nuclides

  2. Radionuclides in house dust

    Energy Technology Data Exchange (ETDEWEB)

    Fry, F A; Green, N; Dodd, N J; Hammond, D J

    1985-04-01

    Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate authorising Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, although radionuclides originating rom the BNFL site can be detected in house dust, this source of contamination is a negligible route of exposure for members of the public in West Cumbria. This report presents the results of the Board's study of house dust in twenty homes in Cumbria during the spring and summer of 1984. A more intensive investigation is being carried out by Imperial College. (author)

  3. Radionuclide body function imager

    International Nuclear Information System (INIS)

    Stoddart, H.F.

    1983-01-01

    A transverse radionuclide scan field imaging apparatus is claimed. It comprises: a plurality of highly focused closely laterally adjacent collimators arranged inwardly focused in an array which surrounds a scan field, each collimator being moveable relative to its adjacent collimator; means for rotating the array about the scan field and means for imparting travel to the collimators

  4. Artificial Consciousness or Artificial Intelligence

    Directory of Open Access Journals (Sweden)

    Spanache Florin

    2017-05-01

    Full Text Available Artificial intelligence is a tool designed by people for the gratification of their own creative ego, so we can not confuse conscience with intelligence and not even intelligence in its human representation with conscience. They are all different concepts and they have different uses. Philosophically, there are differences between autonomous people and automatic artificial intelligence. This is the difference between intelligence and artificial intelligence, autonomous versus automatic. But conscience is above these differences because it is neither conditioned by the self-preservation of autonomy, because a conscience is something that you use to help your neighbor, nor automatic, because one’s conscience is tested by situations which are not similar or subject to routine. So, artificial intelligence is only in science-fiction literature similar to an autonomous conscience-endowed being. In real life, religion with its notions of redemption, sin, expiation, confession and communion will not have any meaning for a machine which cannot make a mistake on its own.

  5. Uranium and Cesium sorption to bentonite colloids in high salinity and carbonate-rich environments: Implications for radionuclide transport

    Science.gov (United States)

    Tran, E. L.; Teutsch, N.; Klein-BenDavid, O.; Weisbrod, N.

    2017-12-01

    When radionuclides are leaked into the subsurface due to engineered waste disposal container failure, the ultimate barrier to migration of radionuclides into local aquifers is sorption to the surrounding rock matrix and sediments, which often includes a bentonite backfill. The extent of this sorption is dependent on pH, ionic strength, surface area availability, radionuclide concentration, surface mineral composition, and solution chemistry. Colloidal-sized bentonite particles eroded from the backfill have been shown to facilitate the transport of radionuclides sorbed to them away from their source. Thus, sorption of radionuclides such as uranium and cesium to bentonite surfaces can be both a mobilization or retardation factor. Though numerous studies have been conducted to-date on sorption of radionuclides under low ionic strength and carbonate-poor conditions, there has been little research conducted on the behavior of radionuclides in high salinities and carbonate rich conditions typical of aquifers in the vicinity of some potential nuclear repositories. This study attempts to characterize the sorption properties of U(VI) and Cs to bentonite colloids under these conditions using controlled batch experiments. Results indicated that U(VI) undergoes little to no sorption to bentonite colloids in a high-salinity (TDS= 9000 mg/L) artificial groundwater. This lack of sorption was attributed to the formation of CaUO2(CO3)22- and Ca2UO2(CO3)3 aqueous ions which stabilize the UO22+ ions in solution. In contrast, Cs exhibited greater sorption, the extent to which was influenced greatly by the matrix water's ionic strength and the colloid concentration used. Surprisingly, when both U and Cs were together, the presence of U(VI) in solution decreased Cs sorption, possibly due to the formation of stabilizing CaUO2(CO3)22- anions. The implications of this research are that rather than undergoing colloid-facilitated transport, U(VI) is expected to migrate similarly to a

  6. Radionuclide cardiography in medical practice

    International Nuclear Information System (INIS)

    Strangfeld, D.; Mohnike, W.; Schmidt, J.; Heine, H.; Correns, H.J.

    1986-01-01

    This publication is a compendium on all aspects of radionuclide diagnostics concerning cardiovascular system diseases. Starting with introductory remarks on the control of cardiovascular diseases the contribution of radionuclide cardiology to functional cardiovascular diagnostics as well as pathophysiological and pathobiochemical aspects of radiocardiography are outlined. Radiopharmaceuticals used in radiocardiography, physical and technical problems in application of radionuclides and their measuring techniques are discussed. In individual chapters radionuclide ventriculography, myocardial scintiscanning, circulatory diagnostics, radionuclide diagnostics of arterial hypertension, of thrombosis and in vitro diagnostics of thrombophilia are treated in the framework of clinical medicine

  7. Acute Mental Discomfort Associated with Suicide Behavior in a Clinical Sample of Patients with Affective Disorders: Ascertaining Critical Variables Using Artificial Intelligence Tools.

    Science.gov (United States)

    Morales, Susana; Barros, Jorge; Echávarri, Orietta; García, Fabián; Osses, Alex; Moya, Claudia; Maino, María Paz; Fischman, Ronit; Núñez, Catalina; Szmulewicz, Tita; Tomicic, Alemka

    2017-01-01

    In efforts to develop reliable methods to detect the likelihood of impending suicidal behaviors, we have proposed the following. To gain a deeper understanding of the state of suicide risk by determining the combination of variables that distinguishes between groups with and without suicide risk. A study involving 707 patients consulting for mental health issues in three health centers in Greater Santiago, Chile. Using 345 variables, an analysis was carried out with artificial intelligence tools, Cross Industry Standard Process for Data Mining processes, and decision tree techniques. The basic algorithm was top-down, and the most suitable division produced by the tree was selected by using the lowest Gini index as a criterion and by looping it until the condition of belonging to the group with suicidal behavior was fulfilled. Four trees distinguishing the groups were obtained, of which the elements of one were analyzed in greater detail, since this tree included both clinical and personality variables. This specific tree consists of six nodes without suicide risk and eight nodes with suicide risk (tree decision 01, accuracy 0.674, precision 0.652, recall 0.678, specificity 0.670, F measure 0.665, receiver operating characteristic (ROC) area under the curve (AUC) 73.35%; tree decision 02, accuracy 0.669, precision 0.642, recall 0.694, specificity 0.647, F measure 0.667, ROC AUC 68.91%; tree decision 03, accuracy 0.681, precision 0.675, recall 0.638, specificity 0.721, F measure, 0.656, ROC AUC 65.86%; tree decision 04, accuracy 0.714, precision 0.734, recall 0.628, specificity 0.792, F measure 0.677, ROC AUC 58.85%). This study defines the interactions among a group of variables associated with suicidal ideation and behavior. By using these variables, it may be possible to create a quick and easy-to-use tool. As such, psychotherapeutic interventions could be designed to mitigate the impact of these variables on the emotional state of individuals, thereby reducing

  8. Artificial Intelligence.

    Science.gov (United States)

    Lawrence, David R; Palacios-González, César; Harris, John

    2016-04-01

    It seems natural to think that the same prudential and ethical reasons for mutual respect and tolerance that one has vis-à-vis other human persons would hold toward newly encountered paradigmatic but nonhuman biological persons. One also tends to think that they would have similar reasons for treating we humans as creatures that count morally in our own right. This line of thought transcends biological boundaries-namely, with regard to artificially (super)intelligent persons-but is this a safe assumption? The issue concerns ultimate moral significance: the significance possessed by human persons, persons from other planets, and hypothetical nonorganic persons in the form of artificial intelligence (AI). This article investigates why our possible relations to AI persons could be more complicated than they first might appear, given that they might possess a radically different nature to us, to the point that civilized or peaceful coexistence in a determinate geographical space could be impossible to achieve.

  9. Radioactivity of natural and artificial building materials - a comparative study.

    Science.gov (United States)

    Szabó, Zs; Völgyesi, P; Nagy, H É; Szabó, Cs; Kis, Z; Csorba, O

    2013-04-01

    Building materials and their additives contain radioactive isotopes, which can increase both external and internal radioactive exposures of humans. In this study Hungarian natural (adobe) and artificial (brick, concrete, coal slag, coal slag concrete and gas silicate) building materials were examined. We qualified 40 samples based on their radium equivalent, activity concentration, external hazard and internal hazard indices and the determined threshold values of these parameters. Absorbed dose rate and annual effective dose for inhabitants living in buildings made of these building materials were also evaluated. The calculations are based on (226)Ra, (232)Th and (40)K activity concentrations determined by gamma-ray spectrometry. Measured radionuclide concentrations and hence, calculated indices and doses of artificial building materials show a rather disparate distribution compared to adobes. The studied coal slag samples among the artificial building materials have elevated (226)Ra content. Natural, i.e. adobe and also brick samples contain higher amount of (40)K compared to other artificial building materials. Correlation coefficients among radionuclide concentrations are consistent with the values in the literature and connected to the natural geochemical behavior of U, Th and K elements. Seven samples (coal slag and coal slag concrete) exceed any of the threshold values of the calculated hazard indices, however only three of them are considered to be risky to use according to the fact that the building material was used in bulk amount or in restricted usage. It is shown, that using different indices can lead to different conclusions; hence we recommend considering more of the indices at the same time when building materials are studied. Additionally, adding two times their statistical uncertainties to their values before comparing to thresholds should be considered for providing a more conservative qualification. We have defined radon hazard portion to point

  10. Laboratory studies of radionuclide transport in fractured Climax granite

    International Nuclear Information System (INIS)

    Failor, R.; Isherwood, D.; Raber, E.; Vandergraaf, T.

    1982-06-01

    This report documents our laboratory studies of radionuclide transport in fractured granite cores. To simulate natural conditions, our laboratory studies used naturally fractured cores and natural ground water from the Climax Granite Stock at the Nevada Test Site. For comparison, additional tests used artificially fractured granite cores or distilled water. Relative to the flow of tritiated water, 85 Sr and /sup 95m/Tc showed little or no retardation, whereas 137 Cs was retarded. After the transport runs the cores retained varying amounts of the injected radionuclides along the fracture. Autoradiography revealed some correlation between sorption and the fracture fill material. Strontium and cesium retention increased when the change was made from natural ground water to distilled water. Artificial fractures retained less 137 Cs than most natural fractures. Estimated fracture apertures from 18 to 60 μm and hydraulic conductivities from 1.7 to 26 x 10 -3 m/s were calculated from the core measurements

  11. Distribution of anthropogenic and naturally occurring radionuclides in soils and lakes of Central Spitsbergen (Arctic)

    International Nuclear Information System (INIS)

    Lokas, Edyta

    2017-01-01

    This work provides the first results on activity concentrations, inventories and activity ratios of the artificial and natural fallout ("1"3"7Cs, "2"3"8Pu, "2"3"9"+"2"4"0Pu, "2"4"1Am, "2"1"0Pb) and lithogenic radionuclides ("2"2"6Ra, "2"2"8Ra, "4"0K) in soils and lake sediments of the inland Spitsbergen. The depths of activity peaks of the artificial radionuclides point to accumulation of up to 10 cm thick deposits during last 50 years. The activity ratios of the radionuclides suggest global fallout as their source. Despite low annual precipitation the inventories of fallout radionuclides in sites not affected by the secondary deposition agree with those reported from the more humid areas of Spitsbergen. (author)

  12. Long-lived radionuclides in the marine environment of Thailand

    International Nuclear Information System (INIS)

    Mahapanyawong, S.; Sonsuk, M.; Polphong, P.; Milintawisamai, M.; Panyatipsakul, Y.

    1992-01-01

    Natural and artificial radionuclides in the environment of the Gulf of Thailand were studied during 1989-1991. In the study, surface water, sediment at 5 locations between latitudes 9 0 28' N and 13 0 15' N longitudes 100 0 35' E. and 5 species of marine biota were collected in 1989. In 1990 and 1991, 9 and 7 species of marine biota were collected from the Gulf of Thailand and the Andaman Sea respectively. These samples were prepared and analyzed for gamma-emitting radionuclides as well as some beta and alpha-emitting radionuclides such as C 14 , Sr 90 , Pu 239,240 , Po 210 etc. The results indicate the present status of radioactivity level of the environment of the gulf and the sea

  13. Long-lived radionuclides in the marine environment of Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Mahapanyawong, S; Sonsuk, M; Polphong, P; Milintawisamai, M; Panyatipsakul, Y

    1993-12-31

    Natural and artificial radionuclides in the environment of the Gulf of Thailand were studied during 1989-1991. In the study, surface water, sediment at 5 locations between latitudes 9 degree 28 minute N and 13 degree 15 minute N longitudes 100 degree 35 minute E. and 5 species of marine biota were collected in 1989. In 1990 and 1991, 9 and 7 species of marine biota were collected from the Gulf of Thailand and the Andaman Sea respectively. These samples were prepared and analyzed for gamma-emitting radionuclides as well as some beta and alpha-emitting radionuclides such as C-14, Sr-90, Pu-239,240, Po-210 etc. The results indicate the present status of radioactivity level of the environment of the gulf and the sea

  14. Long-lived radionuclides in the marine environment of Thailand

    International Nuclear Information System (INIS)

    Mahapanyawong, S.; Sonsuk, M.; Polphong, P.; Milintawisamai, M.; Panyatipsakul, Y.

    1992-01-01

    Natural and artificial radionuclides in the environment of the Gulf of Thailand were studied during 1989-1991. In the study, surface water, sediment at 5 locations between latitudes 9 degree 28 minute N and 13 degree 15 minute N longitudes 100 degree 35 minute E. and 5 species of marine biota were collected in 1989. In 1990 and 1991, 9 and 7 species of marine biota were collected from the Gulf of Thailand and the Andaman Sea respectively. These samples were prepared and analyzed for gamma-emitting radionuclides as well as some beta and alpha-emitting radionuclides such as C-14, Sr-90, Pu-239,240, Po-210 etc. The results indicate the present status of radioactivity level of the environment of the gulf and the sea

  15. Contamination of soil and food with radionuclides from Chernobyl

    International Nuclear Information System (INIS)

    Bikit, I.; Slivka, J.; Veskovic, M.; Conkic, Lj.; Krmar, M.

    2004-01-01

    The results of systematic gamma spectroscopic analyses of fission products performed on the territory of SAP Vojvodina after the Chernobyl accident are presented. Samples of soil grass and food were periodically taken at 5 representative locations and the regions of highest activity concentration are identified on the basis of the results obtained. In the controlled chain soil-plants (feeds)-cow's (milk) on three characteristic locations (soil with different physico-chemical and mechanical properties) the activity concentration of fission radionuclides was determined and transfer factors for soil-plants; feed-milk were calculated. At the territory of hunting sites of SAP Vojvodina, artificial radionuclides were determined in meat and bones of fallow-deer, deer, boar and wild hare; and the highest content of radionuclides was found in meat and bones of boar. (author)

  16. Long-lived radionuclides in the marine environment of Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Mahapanyawong, S; Sonsuk, M; Polphong, P; Milintawisamai, M; Panyatipsakul, Y

    1993-12-31

    Natural and artificial radionuclides in the environment of the Gulf of Thailand were studied during 1989-1991. In the study, surface water, sediment at 5 locations between latitudes 9{sup 0} 28` N and 13{sup 0} 15` N longitudes 100{sup 0} 35` E. and 5 species of marine biota were collected in 1989. In 1990 and 1991, 9 and 7 species of marine biota were collected from the Gulf of Thailand and the Andaman Sea respectively. These samples were prepared and analyzed for gamma-emitting radionuclides as well as some beta and alpha-emitting radionuclides such as C{sup 14}, Sr{sup 90}, Pu{sup 239,240}, Po{sup 210} etc. The results indicate the present status of radioactivity level of the environment of the gulf and the sea.

  17. Artificial intelligence

    OpenAIRE

    Duda, Antonín

    2009-01-01

    Abstract : Issue of this work is to acquaint the reader with the history of artificial inteligence, esspecialy branch of chess computing. Main attention is given to progress from fifties to the present. The work also deals with fighting chess programs against each other, and against human opponents. The greatest attention is focused on 1997 and duel Garry Kasparov against chess program Deep Blue. The work is divided into chapters according to chronological order.

  18. Artificial heart

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-18

    Super-pure plutonium-238 could use heat produced during fission to power an implanted artificial heart. Three model hearts have worked for some time. Concern that excess heat would make the procedure unsafe for humans has broadened the search for another energy source, such as electrohydraulic drive or an external power battery. A back pack approach may provide an interim solution until materials are developed which can withstand heart activity and be small enough for implantation.

  19. EBS Radionuclide Transport Abstraction

    International Nuclear Information System (INIS)

    J. Prouty

    2006-01-01

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

  20. EBS Radionuclide Transport Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    J. Prouty

    2006-07-14

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

  1. EBS Radionuclide Transport Abstraction

    International Nuclear Information System (INIS)

    Schreiner, R.

    2001-01-01

    The purpose of this work is to develop the Engineered Barrier System (EBS) radionuclide transport abstraction model, as directed by a written development plan (CRWMS M and O 1999a). This abstraction is the conceptual model that will be used to determine the rate of release of radionuclides from the EBS to the unsaturated zone (UZ) in the total system performance assessment-license application (TSPA-LA). In particular, this model will be used to quantify the time-dependent radionuclide releases from a failed waste package (WP) and their subsequent transport through the EBS to the emplacement drift wall/UZ interface. The development of this conceptual model will allow Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department to provide a more detailed and complete EBS flow and transport abstraction. The results from this conceptual model will allow PA0 to address portions of the key technical issues (KTIs) presented in three NRC Issue Resolution Status Reports (IRSRs): (1) the Evolution of the Near-Field Environment (ENFE), Revision 2 (NRC 1999a), (2) the Container Life and Source Term (CLST), Revision 2 (NRC 1999b), and (3) the Thermal Effects on Flow (TEF), Revision 1 (NRC 1998). The conceptual model for flow and transport in the EBS will be referred to as the ''EBS RT Abstraction'' in this analysis/modeling report (AMR). The scope of this abstraction and report is limited to flow and transport processes. More specifically, this AMR does not discuss elements of the TSPA-SR and TSPA-LA that relate to the EBS but are discussed in other AMRs. These elements include corrosion processes, radionuclide solubility limits, waste form dissolution rates and concentrations of colloidal particles that are generally represented as boundary conditions or input parameters for the EBS RT Abstraction. In effect, this AMR provides the algorithms for transporting radionuclides using the flow geometry and radionuclide concentrations determined by other

  2. Initial Radionuclide Inventories

    Energy Technology Data Exchange (ETDEWEB)

    H. Miller

    2004-09-19

    The purpose of this analysis is to provide an initial radionuclide inventory (in grams per waste package) and associated uncertainty distributions for use in the Total System Performance Assessment for the License Application (TSPA-LA) in support of the license application for the repository at Yucca Mountain, Nevada. This document is intended for use in postclosure analysis only. Bounding waste stream information and data were collected that capture probable limits. For commercially generated waste, this analysis considers alternative waste stream projections to bound the characteristics of wastes likely to be encountered using arrival scenarios that potentially impact the commercial spent nuclear fuel (CSNF) waste stream. For TSPA-LA, this radionuclide inventory analysis considers U.S. Department of Energy (DOE) high-level radioactive waste (DHLW) glass and two types of spent nuclear fuel (SNF): CSNF and DOE-owned (DSNF). These wastes are placed in two groups of waste packages: the CSNF waste package and the codisposal waste package (CDSP), which are designated to contain DHLW glass and DSNF, or DHLW glass only. The radionuclide inventory for naval SNF is provided separately in the classified ''Naval Nuclear Propulsion Program Technical Support Document'' for the License Application. As noted previously, the radionuclide inventory data presented here is intended only for TSPA-LA postclosure calculations. It is not applicable to preclosure safety calculations. Safe storage, transportation, and ultimate disposal of these wastes require safety analyses to support the design and licensing of repository equipment and facilities. These analyses will require radionuclide inventories to represent the radioactive source term that must be accommodated during handling, storage and disposition of these wastes. This analysis uses the best available information to identify the radionuclide inventory that is expected at the last year of last emplacement

  3. Report on the intercomparison run IAEA-308 radionuclides in seaweed mixture

    International Nuclear Information System (INIS)

    Ballestra, S.; Vas, D.; Lopez, J.J.; Noshkin, V.

    1989-12-01

    The results of an intercomparison exercise on a sample of mixed seaweeds from the Mediterranean Sea, IAEA-308, designed for the determination of artificial and natural radionuclide levels, are reported. The data from 67 laboratories representing 33 countries have been evaluated. The recommended median values, with confidence intervals, for the most frequently measured radionuclides 106 Ru, 110m Ag, 134 Cs, 137 Cs, 238 Pu, 239+240 Pu, 241 Am, 40 K, 210 Pb and 228 Th are given. Refs and tabs

  4. Fukushima Daiichi Radionuclide Inventories

    Energy Technology Data Exchange (ETDEWEB)

    Cardoni, Jeffrey N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jankovsky, Zachary Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-09-01

    Radionuclide inventories are generated to permit detailed analyses of the Fukushima Daiichi meltdowns. This is necessary information for severe accident calculations, dose calculations, and source term and consequence analyses. Inventories are calculated using SCALE6 and compared to values predicted by international researchers supporting the OECD/NEA's Benchmark Study on the Accident at Fukushima Daiichi Nuclear Power Station (BSAF). Both sets of inventory information are acceptable for best-estimate analyses of the Fukushima reactors. Consistent nuclear information for severe accident codes, including radionuclide class masses and core decay powers, are also derived from the SCALE6 analyses. Key nuclide activity ratios are calculated as functions of burnup and nuclear data in order to explore the utility for nuclear forensics and support future decommissioning efforts.

  5. Radionuclide table. Pt. 1

    International Nuclear Information System (INIS)

    Legrand, Jean; Perolat, J.-P.; Lagoutine, Frederic; Le Gallic, Yves.

    The evaluation of the following 29 radionuclides is presented: 22 Na, 24 Na, sup(24m)Na, 51 Cr, 54 Mn, 57 Co, 58 Co, sup(58m)Co, 60 Co, sup(60m)Co, 75 Se, 103 Ru, sup(103m)Rh, sup(110m)Ag- 110 Ag, 109 Cd, 125 Sb, sup(125mTe), 125 I, 133 Xe, sup(133m)Xe, 131 Cs, 134 Cs, sup(134m)Cs, 139 Ce, 144 Ce- 144 Pr, 144 Pr, 169 Er, 186 Re, 203 Hg. The introduction contains a brief description of radioactive processes and the evaluation rules followed. The best values and associated uncertainties are given for each radionuclide for the major parameters of the decay scheme and the radiation intensities emitted, together with a decay table. Gamma, X-rays and sometimes conversion electron spectra are also provided [fr

  6. Radionuclide co-precipitation

    International Nuclear Information System (INIS)

    Bruno, J.; Sandino, A.

    1987-12-01

    The thermodynamic and kinetic behaviour of the minor components of the spent fuel matrix has been theoretically and experimentally investigated. Two different situations have been studied: Part I, the near field scenario, where the release and migration of the minor components is dependent on the solubility behaviour of UO 2 (s); Part II, the far field, where the solubility and transport of the radionuclides is related to the major geochemical processes occurring. (orig.)

  7. Geochemistry and radionuclide migration

    International Nuclear Information System (INIS)

    Isherwood, D.

    1978-01-01

    Theoretically, the geochemical barrier can provide a major line of defense in protecting the biosphere from the hazards of nuclear waste. The most likely processes involved are easily identified. Preliminary investigations using computer modeling techniques suggest that retardation is an effective control on radionuclide concentrations. Ion exchange reactions slow radionuclide migration and allow more time for radioactive decay and dispersion. For some radionuclides, solubility alone may limit concentrations to less than the maximum permissible now considered acceptable by the Federal Government. The effectiveness of the geochemical barrier is ultimately related to the repository site characteristics. Theory alone tells us that geochemical controls will be most efficient in an environment that provides for maximum ion exchange and the precipitation of insoluble compounds. In site selection, consideration should be given to rock barriers with high ion exchange capacity that might also act as semi-permeable membranes. Also important in evaluating the site's potential for effective geochemical controls are the oxidation potentials, pH and salinity of the groundwater

  8. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Howard, B.J.; Kennedy, V.H.; Nelson, A.

    1983-06-01

    A bibliographical database has been developed to provide quick access to research and background literature in the field of radioecology. This is a development of an earlier database described by Nelson (Bocock 1981). ITE's particular fields of interest have led to a subject bias in the bibliography towards studies in Cumbria, especially those concerned with radionuclides originating from the reprocessing plant at Sellafield, and towards ecological research studies that are complementary to radionuclide studies. Other subjects covered, include the chemistry of radionuclides, budgets and transfers within ecosystems and techniques for the analysis of environmental samples. ITE's research objectives have led to the establishment of a specialized database which is intended to complement rather than compete with the large international databases made available by suppliers such as IRS-DIALTECH or DIALOG. Currently the database holds about 1900 references which are stored on a 2 1/2 megabyte hard disk on a Digital PDP11/34 computer operating under a time shared system. The references follow a standard format. (author)

  9. Radionuclides in marine organisms

    International Nuclear Information System (INIS)

    Honda, Teruyuki

    2001-01-01

    The concentration and accumulation of radionuclides in marine organisms were explained in this paper. Secular change of the radioactivity concentration of 137 Cs in seaweed in coastal area of Japan showed more than 5Bq/kg-fresh in the first half of 1960, but decreased less than 1 Bq/kg-fresh after then and attained to less than 0.1 Bq/kg-fresh in 1990s. However, the value increased a while in 1986, which indicated the effect of Chernobyl accident. The accident increased 137 Cs of shellfish near Japan. The concentration of 239+240 Pu was the lowest value in muscles of fish, but increased from 1.7 to 42.3 mBq/kg wet wt in seaweed in 1999. 99 Tc concentration of seaweed showed from 100 to 1000 times as much as that of seawater. Radionuclides in the Irish Sea are originated from Sellafield reprocessing plant. The concentration factors of macro-algae and surface water fish (IAEA,1985) were shown. Analytical results of U in 61 kinds of marine organs showed that the concentration was different in the part of organ. The higher concentration of U was observed in hard tissue of fish. The concentration factor was different between chemical substances with the same radionuclides. (S.Y.)

  10. Radionuclides in thyroid cancer

    International Nuclear Information System (INIS)

    Mahadev, V.

    1980-01-01

    The three main areas of application of radionuclides in thyroid disease will be reviewed. Firstly thyroid radionuclide imaging in thyroid swellings, in relationship to lumps in the neck and ectopic thyroid tissue such as retrosternal goitre, and lingual goitre will be described. Future developments in the field including tomographic scanning, using the coded aperture method, and fluorescent scans and ultrasound are reviewed. The second area of application is the assessment and evaluation of thyroid function and the therapy of Grave's Disease and Plummer's Disease using radioiodine. The importance of careful collection of the line of treatment, results of treatment locally and the follow-up of patients after radioiodine therapy will be described. The third area of application is in the diagnosis and therapy of thyroid cancer. Investigation of thyroid swelling, and the diagnosis of functioning metastases are reported. The therapeutic iodine scan as the sole evidence of functioning metastatic involvement is recorded. Histological thyroid cancer appears to be increasingly encountered in clinical practice and the plan of management in relation to choice of cases for therapeutic scanning is discussed with case reports. Lastly the role of whole body scanning in relationship to biochemical markers is compared. In the changing field of nuclear medicine radionuclide applications in thyroid disease have remained pre-eminent and this is an attempt to reassess its role in the light of newer developments and local experience in the Institute of Radiotherapy, Oncology and Nuclear Medicine. (author)

  11. Artificial radionuclides in an intertidal sediment from northwest England

    International Nuclear Information System (INIS)

    Morris, K.; Keith-Roach, M.J.; Butterworth, J.C.; Livens, L.K.; Day, J.P.; Hursthouse, A.S.; Fifield, L.K.; Bardgett, R.D.

    1998-01-01

    An intertidal sediment core has been analysed for the principal transuranium elements present in the BNFL Sellafield radioactive waste discharges (Np, Pu, Am) and the high yield fission products 99 Tc and 137 Cs. Interstitial water samples were collected using porous cup samplers and early results from these analyses show that there is a pronounced seasonality in the pattern of dissolved Pu, which apparently relates to changes in dissolved Fe and Mn. More recent work has concentrated on the characterization of changes in the sediment microbial community and on the development of analytical methods for the analysis of dissolved Np, apparently the most readily mobilized of the transuranic elements, which is present at concentrations of the order of 10 8 atoms/litre

  12. Artificial graphites

    International Nuclear Information System (INIS)

    Maire, J.

    1984-01-01

    Artificial graphites are obtained by agglomeration of carbon powders with an organic binder, then by carbonisation at 1000 0 C and graphitization at 2800 0 C. After description of the processes and products, we show how the properties of the various materials lead to the various uses. Using graphite enables us to solve some problems, but it is not sufficient to satisfy all the need of the application. New carbonaceous material open application range. Finally, if some products are becoming obsolete, other ones are being developed in new applications [fr

  13. Natural radionuclides in select matrices of terrestrial food chain around Kudankulam nuclear power station, India

    International Nuclear Information System (INIS)

    Ross, E.M.; Wesley, S.G.

    2016-01-01

    Natural radionuclides entering the food chain are mostly derived from the soil. There is a variation in soil radionuclide content in different geographic regions. Uptake of radionuclides by plants also varies from species to species and depends on many factors. Human food and animal feed derived from such regions may have varying levels of radionuclides. Intake of food/feed will be reflected in the next consumer level of the food chain. Such studies are essential around a nuclear power plant where there can be exposure from natural as well as artificial radionuclides. In this study an effort was taken to study the intake and excretion of 40 K, 226 Ra and 228 Ra levels along the soil-grass-cow pathway

  14. Analysis of the behavior of radionuclides migration in fractured medium in different types of rocks matrices; Análise do comportamento da migração de radionuclídeos em meio fraturado em diferentes tipos de matrizes rochosas

    Energy Technology Data Exchange (ETDEWEB)

    Sá, Ludimila Silva Salles de; Silveira, Cláudia Siqueira da; Lima, Zelmo Rodrigues de, E-mail: Ludimilasalles.md@gmail.com, E-mail: siqueira_claudia@yahoo.com.br, E-mail: zelmolima@yahoo.com.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Eletrobrás Termonuclear S.A. (ELETRONUCLEAR), Rio de Janeiro, RJ (Brazil); Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-11-01

    In management of radioactive wastes, the current trend is to dispose the radioactive waste for long life and high activity in permanent repositories of depth, geologically stable and low permeability. Thus, it is relevant to analyze the groundwater movement process, because the mechanism by which the radionuclides in a repository with fractures could return to the surface would be through the groundwater circulation system. A common problem encountered is the modeling of the migration of radionuclides in a fractured medium. The objective of this work is to evaluate the behavior of the migration of radionuclides in two types of rock matrix, considering the following properties: volumetric density, porosity, distribution coefficient and molecular diffusion coefficient. The physical system adopted consists of the matrix rock containing a discrete fracture in a porous medium saturated with water. The partial differential equations that describe the radionuclide movement were discretized by finite differences, and the Implicit Euler method was adopted. While for the convective term the numerical scheme of progressive differences was used.

  15. Gut-related studies of radionuclide toxicity

    International Nuclear Information System (INIS)

    Sullivan, M.F.

    1985-01-01

    The behavior of radioactive materials that may be ingested as a consequence of a reactor accident, unavoidable occupational exposure, or after release to the environment and incorporation into the food chain is investigated. Current emphasis is on evaluating hazards from ingested actinides as a function of animal age, species, nutrition, and diet, or chemicophysical state of the actinide. The authors are also concerned with the behavior of actinides that are inhaled and pass through the gastro-intestinal tract after clearance from the lungs. The radionuclides being investigated are 238 Pu, 241 Am, 244 Cm, 147 Pm, 109 Cd, and 210 Pb. 2 tables

  16. Concentration of some radionuclides in Moringa Oliefera plant

    International Nuclear Information System (INIS)

    Abd elbagi, W. K. A.

    2013-07-01

    This study has been conducted to determine the radioactivity concentration of naturally occurring radionuclides 228 U, 232 Th, and 40 K in samples of Moringaoliefera plants in Khartoum Bahry Elsamrab by using γ ray spectrometry sodium iodide detector and high purity germanium detector. A total of 30 samples, 10 samples from leaves, 10 samples from seeds and 10 samples from soil of samples have been collected. For leaves the radionuclide activity concentrations in samples analyzed with the mean of 2767.266±78.6741 Bq kg - 1 for 238 U, 3486.817±80.98811 Bq kg - 1 for 238 Th and 2273.386±54.152 Bq kg - 1 for 40 K. For seeds the radionuclide activity concentration in samples analyzed with the mean of 2839.224±72.6016 Bq kg - 1 for 238 U, 2844.372±78.74919 Bq kg - 1 for 2 38T h and 2377.005±91.8838 Bq kg - 1 for 40 K. No trace of artificial radionuclide has been determined in all the samples. The effective dose due to the presence of these radionuclides has been estimated and found 0.89μSv/year and 0.1015μSv/year for 232 Th, 238 U and 40 K, respectively.(Author)

  17. Assessment of radionuclide contents in food in Hong Kong

    International Nuclear Information System (INIS)

    Yu, K.N.; Mao, S.Y.

    1999-01-01

    Baseline values of concentrations of the natural radionuclides ( 238 U, 226 Ra, 228 Ra/ 232 Th, 210 Pb) and artificial radionuclides ( 137 Cs, 60 Co) in food and drinks (tap water, milk, and water-based drinks) were determined by gamma spectroscopy. All food and drinks were found to contain detectable 40 K contents: 0.1 to 160 Bq Kg -1 for food and 0.006 to 61 Bq L -1 for drinks. Most of the other natural radionuclides in solid food were found to have contents below the minimum detectable activities (MDA). More samples in the leafy vegetable, tomato, carrot and potato categories contained detectable amounts of 228 Ra than the meat, cereal, and fish categories, with concentrations up to 1.2 Bq kg -1 for the former categories and 0.35 Bq kg -1 for the latter categories. The 238 U and 226 Ra radionuclides were detectable in most of the water-based drink samples, and the 228 Ra and 210 Pb radionuclides were detectable in fewer water-based drink samples. The 137 Cs contents in solid food were detectable in most of the solid food samples (reaching 0.59 Bq kg -1 ), but in drinks the 137 Cs contents were very low and normally lower than the MDA values. Nearly all the 60 Co contents in food and drinks were below the MDA values and their contents were below those of 137 Cs

  18. Natural radionuclides in soils from Sao Paulo State cerrado forest

    International Nuclear Information System (INIS)

    Miranda, Marcia V.F.E.S.; Farias, Emerson E.G. de; Cantinha, Rebeca S.; Franca, Elvis J. de

    2015-01-01

    Considering the long life history, forests should be preferentially evaluated for the monitoring of radionuclides, mainly artificial radioisotopes. However, little is known about nuclides from Uranium and Thorium series, as well as, K-40, in soils from the Sao Paulo State forests. Soils are the main reservoir of natural radionuclides for vegetation, thereby deserving attention. Taking into account the advantages of High-Resolution Gamma-ray Spectrometry (HRGS), diverse radionuclides can be quantified simultaneously. In this work natural radionuclides in soils from the Estacao Ecologica de Assis were evaluated by HRGS. Samples of 0-10 cm depth were collected under crown projection of most abundant tree species of long-term plots installed within the Estacao Ecologica de Assis, Sao Paulo State, Brazil. After drying and milling until 0.5 mm particle size, test portions of 30 g were transferred to polypropylene vials, sealed with silicone and kept under controlled conditions until 30 days to achieve secular equilibrium. A group of gamma-ray spectrometers was used to analyze about 27 samples by 80,000 seconds. Activity concentrations of Pb-214, Ac-228 and K-40 and their respective expanded analytical uncertainties at the 95% confidence level were calculated by Genie software from Canberra. Abnormal values were not detected for radionuclides in soils samples, however K-40 activity concentrations changed considerably due to the mineral cycling, in which K and, consequently K-40, is mainly stocked in vegetation in spite of soils. (author)

  19. Natural radionuclides in soils from Sao Paulo State cerrado forest

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Marcia V.F.E.S.; Farias, Emerson E.G. de; Cantinha, Rebeca S.; Franca, Elvis J. de, E-mail: mvaleria@cnen.gov.br, E-mail: emersonemiliano@yahoo.com.br, E-mail: rebecanuclear@gmail.com, E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2015-07-01

    Considering the long life history, forests should be preferentially evaluated for the monitoring of radionuclides, mainly artificial radioisotopes. However, little is known about nuclides from Uranium and Thorium series, as well as, K-40, in soils from the Sao Paulo State forests. Soils are the main reservoir of natural radionuclides for vegetation, thereby deserving attention. Taking into account the advantages of High-Resolution Gamma-ray Spectrometry (HRGS), diverse radionuclides can be quantified simultaneously. In this work natural radionuclides in soils from the Estacao Ecologica de Assis were evaluated by HRGS. Samples of 0-10 cm depth were collected under crown projection of most abundant tree species of long-term plots installed within the Estacao Ecologica de Assis, Sao Paulo State, Brazil. After drying and milling until 0.5 mm particle size, test portions of 30 g were transferred to polypropylene vials, sealed with silicone and kept under controlled conditions until 30 days to achieve secular equilibrium. A group of gamma-ray spectrometers was used to analyze about 27 samples by 80,000 seconds. Activity concentrations of Pb-214, Ac-228 and K-40 and their respective expanded analytical uncertainties at the 95% confidence level were calculated by Genie software from Canberra. Abnormal values were not detected for radionuclides in soils samples, however K-40 activity concentrations changed considerably due to the mineral cycling, in which K and, consequently K-40, is mainly stocked in vegetation in spite of soils. (author)

  20. Statistical analysis of fallout radionuclides transfer to paddy-field rice

    International Nuclear Information System (INIS)

    Takahashi, T.; Morisawa, S.; Inoue, Y.

    1996-01-01

    Radionuclides released from nuclear facilities to atmosphere are transported through various pathways in biosphere and cause human exposure. Among these radionuclides transfer pathways, an ingestion of crops containing radionuclides is one of the dominant pathway for human exposure. For the safety assessment of nuclear facilities, it is important to understand the behavior of radionuclides in agricultural environment and to describe them in a mathematical model. In this paper, a statistical model is proposed for estimating the concentration of fallout radionuclides in paddy-field rice, the staple food for Japanese people. For describing behavior of fallout radionuclides in a paddy-field, a dynamic model and a statistical model have been proposed respectively. The model used in this study has been developed assuming that the amount of radionuclides transfer to brown rice (hulled rice) or polished rice through direct deposition of airborne radionuclides (the direct deposition pathway) and root uptake from a paddy soil (the root uptake pathway) are proportional to the deposition flux of radionuclides and concentration of radionuclides in paddy soil respectively. That is, the model has two independent variables; the deposition flux of radionuclides and the concentration of radionuclides in the paddy soil, and has single dependent variable; the concentration of radionuclides in brown rice or polished rice. The regression analysis is applied by using environmental monitoring data. Then the distribution of radionuclides between rice-bran (skin part of rice crop) and polished rice (core part) through both the direct deposition pathway and the root uptake pathway are evaluated by the model. (author)

  1. Airborne radionuclides in the proglacial environment as indicators of sources and transfers of soil material.

    Science.gov (United States)

    Łokas, Edyta; Wachniew, Przemysław; Jodłowski, Paweł; Gąsiorek, Michał

    2017-11-01

    A survey of artificial ( 137 Cs, 238 Pu, 239+240 Pu, 241 Am) and natural ( 226 Ra, 232 Th, 40 K, 210 Pb) radioactive isotopes in proglacial soils of an Arctic glacier have revealed high spatial variability of activity concentrations and inventories of the airborne radionuclides. Soil column 137 Cs inventories range from below the detection limit to nearly 120 kBq m -2 , this value significantly exceeding direct atmospheric deposition. This variability may result from the mixing of materials characterised by different contents of airborne radionuclides. The highest activity concentrations observed in the proglacial soils may result from the deposition of cryoconites, which have been shown to accumulate airborne radionuclides on the surface of glaciers. The role of cryoconites in radionuclide accumulation is supported by the concordant enrichment of the naturally occurring airborne 210 Pb in proglacial soil cores showing elevated levels of artificial radionuclides. The lithogenic radionuclides show less variability than the airborne radionuclides because their activity concentrations are controlled only by the mixing of material derived from the weathering of different parent rocks. Soil properties vary little within and between the profiles and there is no unequivocal relationship between them and the radionuclide contents. The inventories reflect the pathways and time variable inputs of soil material to particular sites of the proglacial zone. Lack of the airborne radionuclides reflects no deposition of material exposed to the atmosphere after the 1950s or its removal by erosion. Inventories above the direct atmospheric deposition indicate secondary deposition of radionuclide-bearing material. Very high inventories indicate sites where transport pathways of cryoconite material terminated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Chapter 2. Radionuclides in the biosphere

    International Nuclear Information System (INIS)

    Toelgyessy, J.; Harangozo, M.

    2000-01-01

    This is a chapter of textbook of radioecology for university students. In this chapter authors deal with role of radionuclides in the biosphere. Chapter consists of next parts: (1) Natural radionuclides in biosphere; (2) Man-made radionuclides in the biosphere; (3) Ecologically important radionuclides; (4) Natural background; (5) Radiotoxicity and (6) Paths of transfer of radionuclides from the source to human

  3. Radionuclide diagnosis of emergency states

    International Nuclear Information System (INIS)

    Ishmukhametov, A.I.

    1985-01-01

    Solution of emergency state radionuclide diagnostics from the technical point of view is provided by the application of the mobile quick-operating equipment in combination with computers, by the use of radionuclides with acceptable for emergency medicine characteristics and by development of radionuclide investigation data propcessing express-method. Medical developments include the study of acute disease and injury radioisotope semiotics, different indication diagnostic value determining, comparison of the results, obtained during radionuclide investigation, with clinicolaboratory and instrumental data, separation of methodical complex series

  4. History of medical radionuclide production.

    Science.gov (United States)

    Ice, R D

    1995-11-01

    Radionuclide production for medical use originally was incidental to isotope discoveries by physicists and chemists. Once the available radionuclides were identified they were evaluated for potential medical use. Hevesy first used 32P in 1935 to study phosphorous metabolism in rats. Since that time, the development of cyclotrons, linear accelerators, and nuclear reactors have produced hundreds of radionuclides for potential medical use. The history of medical radionuclide production represents an evolutionary, interdisciplinary development of applied nuclear technology. Today the technology is represented by a mature industry and provides medical benefits to millions of patients annually.

  5. EBS Radionuclide Transport Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    J.D. Schreiber

    2005-08-25

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport

  6. EBS Radionuclide Transport Abstraction

    International Nuclear Information System (INIS)

    J.D. Schreiber

    2005-01-01

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers

  7. Natural and Artificial Radioactivity in Drinking Water in Malaga, Spain

    International Nuclear Information System (INIS)

    Duenas, C.; Fernandez, M.C.; Gordo, E.; Canete, S.; Perez, M.

    2011-01-01

    Water has a vast importance for numerous human activities, so that securing supplies of drinking water of a standard quality is becoming more and more difficult. The measurement of radioactivity in drinking water permits us to determine the exposure of the population to radiation from the habitual consumption of water. The occurrence of radionuclides in drinking water gives rise to internal exposure of humans, directly on the decay of radionuclides taken into the body through ingestion and inhalation and indirectly when they are incorporated as part of the food-chain The measurement of radioactivity in drinking water permits us to determine the exposure of population to radiation from the habitual consumption of water. An intensive study of the water supply in the city of Malaga during 2002-2010 has been carried out in order to determine the gross alpha activities, gross beta activities and natural and artificial radionuclides present in drinking water. A data base on natural and artificial radioactivity in water was produced. The results indicated that a high percentage of the water sample contains a total gross alpha and beta less than 0.10 Bq/l and 1 Bq/l respectively. The main objectives were: 1) to analyses gross alpha and gross beta activities and to know the statistical distributions. 2) to study the levels of natural and artificial radionuclides 3) to determine a possible mathematical correlation between the radionuclides and several factors.

  8. Radionuclide speciation in the environment: a review

    International Nuclear Information System (INIS)

    Moulin, V.; Moulin, C.

    2001-01-01

    Speciation determination is of prime importance to explain and evaluate the mobility, the toxicity and the risk resulting from the presence of trace elements in natural systems, in particular in the case of radionuclides, in the framework of environment and waste management purposes. The present paper will then focus more specifically on the physico-chemical speciation of radionuclides, and more particularly of actinides, in the environment, with emphasis on the behavior in solution: from a chemical point of view (with important ligands including colloidal phases) using experimental data and speciation calculations, as well as from a more technical point of view (with analytical methods for in situ speciation determination and thermodynamic data determination). A review of recent papers (mainly from CEA) is presented. (orig.)

  9. Sorption of radionuclides on a soil

    International Nuclear Information System (INIS)

    Fukui, Masami

    1979-01-01

    Disposal of radioactive wastes into the ground has been discussed, and this paper emphasized significance of the investigation for underground water flow and for the prediction of radionuclides through a stratified aquifer using column experiments to evaluate the internal radiation dose. Distributions and redistributions of radionuclides in a sandy layer were observed to identify the sorption model which predicts the behavior, and the underground water flow in the Plio-Pleistocene Osaka Group was investigated as an example, by mean of the measurement of 222 Rn concentration, the pumping technique and the tracer technique using the activation analysis. Then, the estimation of radioactive concentration in the underground water was worked out for the boundary condition of steady state inflow of liquid wastes and of which the 90 Sr are leached from the solidified body, moreover, the equation which easily evaluates the suitability of the disposal site was proposed. These approach may be useful for the actual site selection of radioactive wastes disposal. (author)

  10. Use of artificial tracers in hydrology

    International Nuclear Information System (INIS)

    1991-05-01

    The IAEA has convened an Advisory Group Meeting with the following objectives: To define the role of artificial radioactive tracers for water tracing in comparison with other non-radioactive tracers. To evaluate the real needs of artificial radioactive tracers in hydrology. To identify the fields for which artificial radioactive tracers are useful as well as those in which they can be substituted by other tracers. To discuss the strategy to be adopted to overcome the difficulties derived from the restrictions on the use of radioactive tracers in hydrology. The meeting was held at IAEA Headquarters from 19 to 22 March 1990, and was attended by 30 participants from 15 Member States. The conclusions and recommendations are that the use of artificial radioactive tracers should be restricted to cases where other tracers cannot be used or do not provide the same quality of information. Tritium, iodine-131, bromine-82, chromium-51 in the form of Cr-EDTA, technetium-99m obtained from 99 Mo-generators and gold-198 as an adsorbable tracer are, practically, the only radionuclides used for water tracing. The use of other radionuclides for this purpose does not appear to be necessary, possible and/or convenient. Refs, figs and tabs

  11. Osteopetrosis: Radiological & Radionuclide Imaging

    International Nuclear Information System (INIS)

    Sit, Cherry; Agrawal, Kanhaiyalal; Fogelman, Ignac; Gnanasegaran, Gopinath

    2015-01-01

    Osteopetrosis is a rare inherited bone disease where bones harden and become abnormally dense. While the diagnosis is clinical, it also greatly relies on appearance of the skeleton radiographically. X-ray, radionuclide bone scintigraphy and magnetic resonance imaging have been reported to identify characteristics of osteopetrosis. We present an interesting case of a 59-year-old man with a history of bilateral hip fractures. He underwent 99m Tc-methylene diphosphonate whole body scan supplemented with single-photon emission computed tomography/computed tomography of spine, which showed increased uptake in the humeri, tibiae and femora, which were in keeping with osteopetrosis

  12. Modifying radionuclide effects

    International Nuclear Information System (INIS)

    Sasser, L.B.

    1983-01-01

    This project involves a study of the relationship of physiological and environmental factors to the metabolism and effects of radionuclides. We have studied placental transfer and suckling as pathways of americium entry into the newborn or juvenile rat. Rats were injected intravenously with 5 μCi of 241 Am while nulliparous (30 days prior to mating), pregnant (day 19 of gestation), or lactating (1 day after parturition), and subsequent litters were killed to determine 241 Am retention. A deficit in reproductive performance was observed in the group injected before mating, as evidenced by reduced number and weight of offspring

  13. Radionuclides in the sea

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1971-07-01

    Water covers a little more than two-thirds of the earth's surface. What is thrown into the sea from a ship may be washed up on a shore thousands of miles away; wastes discharged into the seas or into rivers flowing into them can affect marine life and possibly also the health of man. The study, prevention and control of pollution of the seas and oceans by radionuclides introduced as by-products of man's use of nuclear energy is thus of global interest. (author)

  14. Sherlock Holmes for radionuclides

    International Nuclear Information System (INIS)

    Schmitzer, C.

    2002-01-01

    At the end of 2001 ARC Seibersdorf research has taken the management of the first worldwide certified laboratory to control the realization of the international Comprehensive Nuclear Test Ban Treaty (CTBT). Altogether there will be 16 CTBT certified laboratories worldwide; therefore a global network of radionuclides measurements stations and test laboratories as well as seismic, radiation and hydroacustic measurements stations is necessary . In the future air samples will be taken from these stations and analyzed in one of these certified laboratories, when appears the suspicion that an atomic test was carried out. (nevyjel)

  15. The accumulation of radionuclides in stevia (Stevia rebaudiana Bertoni) in conditions of the Ararat valley

    International Nuclear Information System (INIS)

    Babakhanyan, M.A.; Ghalachyan, L.M.; Hovhannisyan, L.E.

    2013-01-01

    Accumulation peculiarities of artificial ( 137 Cs, 90 Sr) and natural (U) radionuclides (RN) in Stevia (Stevia rebaundiana Bertoni), grown in hydroponics and soils near G.S. Davtyan Institute of Hydroponics Problems have been studied. It turned out that the raw material of Stevia, cultivated in open-air hydroponics was clearer than the soil variant. The content of controlled artificial RN ( 137 Cs, 90 Sr) in Stevia cultivated in soil and in hydroponics conditions hasn't exceeded the MAC

  16. Radionuclide Therapy. Chapter 19

    Energy Technology Data Exchange (ETDEWEB)

    Flux, G.; Du, Yong [Royal Marsden Hospital and Institute of Cancer Research, Surrey (United Kingdom)

    2014-12-15

    Cancer has been treated with radiopharmaceuticals since the 1940s. The radionuclides originally used, including 131I and 32P, are still in use. The role of the physicist in radionuclide therapy encompasses radiation protection, imaging and dosimetry. Radiation protection is of particular importance given the high activities of the unsealed sources that are often administered, and must take into account medical staff, comforters and carers, and, as patients are discharged while still retaining activity, members of the public. Regulations concerning acceptable levels of exposure vary from country to country. If the administered radiopharmaceutical is a γ emitter, then imaging can be performed which may be either qualitative or quantitative. While a regular system of quality control must be in place to prevent misinterpretation of image data, qualitative imaging does not usually rely on the image corrections necessary to determine the absolute levels of activity that are localized in the patient. Accurate quantitative imaging is dependent on these corrections and can permit the distribution of absorbed doses delivered to the patient to be determined with sufficient accuracy to be clinically beneficial.

  17. Intervention procedures for radionuclides

    International Nuclear Information System (INIS)

    Adelstein, S.J.

    1991-01-01

    As in the case of smoking and lung cancer, for large radionuclide releases, an ounce of prevention is worth a pound of cure. On the other hand, we feel compelled to do something sensible after an accident even if the principal benefit of intervention may be to comfort the population at risk. Of course, for populations near the site of an accident, evacuation should be considered, but it is unreasonable to apply this measure to distant populations, e.g., large segments of the European community could not be moved about as we observe the shifting of a radioactive cloud in response to changing winds. If the radionuclides are delivered as particulates, bringing people indoors and employing primitive air filters can temporarily reduce exposures, but these stratagems are not very effective against gaseous or volatile elements. What, then, can be done for populations downwind of a radioactive release whose air, water, and/or food supply are, or are about to become contaminated? 5 refs

  18. Some parameters of radionuclide kinetics

    International Nuclear Information System (INIS)

    Prokof'ev, O.N.; Smirnov, V.A.; Belen'kij, E.I.

    1978-01-01

    Numerical values of the rates of radionuclide absorption into, and elimination from, bovine organs were determined. Kinetic rate constants of radionuclides such as 89 Sr, 99 Mo, 131 I, 132 Tl, and 140 Be were calculated. The calculations were done for muscle, liver, and kidney

  19. Radionuclide - Soil Organic Matter Interactions

    DEFF Research Database (Denmark)

    Carlsen, Lars

    1985-01-01

    Interactions between soil organic matter, i.e. humic and fulvic acids, and radionuclides of primary interest to shallow land burial of low activity solid waste have been reviewed and to some extent studied experimentally. The radionuclides considered in the present study comprise cesium, strontium...

  20. Erosion of atmospherically deposited radionuclides as affected by soil disaggregation mechanisms

    International Nuclear Information System (INIS)

    Claval, D.; Garcia-Sanchez, L.; Real, J.; Rouxel, R.; Mauger, S.; Sellier, L.

    2004-01-01

    The interactions of soil disaggregation with radionuclide erosion were studied under controlled conditions in the laboratory on samples from a loamy silty-sandy soil. The fate of 134 Cs and 85 Sr was monitored on soil aggregates and on small plots, with time resolution ranging from minutes to hours after contamination. Analytical experiments reproducing disaggregation mechanisms on aggregates showed that disaggregation controls both erosion and sorption. Compared to differential swelling, air explosion mobilized the most by producing finer particles and increasing five-fold sorption. For all the mechanisms studied, a significant part of the contamination was still unsorbed on the aggregates after an hour. Global experiments on contaminated sloping plots submitted to artificial rainfalls showed radionuclide erosion fluctuations and their origin. Wet radionuclide deposition increased short-term erosion by 50% compared to dry deposition. A developed soil crust when contaminated decreased radionuclide erosion by a factor 2 compared to other initial soil states. These erosion fluctuations were more significant for 134 Cs than 85 Sr, known to have better affinity to soil matrix. These findings confirm the role of disaggregation on radionuclide erosion. Our data support a conceptual model of radionuclide erosion at the small plot scale in two steps: (1) radionuclide non-equilibrium sorption on mobile particles, resulting from simultaneous sorption and disaggregation during wet deposition and (2) later radionuclide transport by runoff with suspended matter

  1. Correlation between meteorological conditions and the concentration of radionuclides in the ground layer of atmospheric air

    International Nuclear Information System (INIS)

    Krajny, E.; Osrodka, L.; Wojtylak, M.; Michalik, B.; Skowronek, J.

    2001-01-01

    The main goal of this work was to find correlation between the concentrations of radionuclides in outdoor air and the meteorological conditions like: atmospheric pressure, wind velocity and amount of precipitation. Because the sampling period of radionuclides concentrations in air was relatively long (7 days), the average levels of meteorological parameters have been calculated within the same time. Data of radionuclide concentrations and meteorological data have been analyzed in order to find statistical correlation. The regression analysis and one of AI methods, known as neural network, were applied. In general, analysis of the gathered data does not show any strong correlation between the meteorological conditions and the concentrations of the radionuclides in air. A slightly stronger correlation we found for radionuclides with relatively short half-lives. The only positive correlation has been found between the 7 Be concentration and air temperature (at the significance level α = 0.05). In our opinion, the lack of correlation was caused by a too long sampling time in measurements of radionuclides in outdoor air (a whole week). Results of analysis received by means of the artificial neuron network are better. We were able to find certain groups of meteorological conditions, related with the corresponding concentrations of particular radionuclides in air. Preliminary measurements of radon progeny concentration support the thesis that the link between changes of meteorological parameters and concentrations of radionuclides in ambient air must exist. (author)

  2. Gut-related radionuclide studies

    International Nuclear Information System (INIS)

    Sullivan, M.F.

    1982-01-01

    This project is concerned with the behavior of radioactive materials that may be ingested as a consequence of a reactor accident, unavoidable occupational exposure, or after release to the environment and incorporation into the food chain. Current emphasis is directed toward evaluating hazards from ingested actinides as a function of animal age, species, nutrition, and diet, or chemicophysical state of the actinide. Recent observations indicate that the influence of chemical form on plutonium absorption observed at high mass levels does not occur at low mass concentrations. For example, at doses of 0.6 μg/kg there was no difference between absorption of the carbonate, citrate or nitrate forms of plutonium. However, at 1.5 mg/kg, the citrate was absorbed in quantities 30 times higher than the nitrate. The opposite effect occurred for neptunium GI absorption. Furthermore, it was demonstrated that materials such as citrus fruit juices and calcium, as well as drugs that affect GI function (such as aspirin and DTPA), markedly influence GI absorption of plutonium. Such studies provide evidence that diet and nutritional state should be considered in establishing safe limits for radionuclides that may be ingested

  3. Radionuclides in an underground environment

    International Nuclear Information System (INIS)

    Thompson, J.L.

    1996-01-01

    In the 100 years since Becquerel recognized radioactivity, mankind has been very successful in producing large amounts of radioactive materials. We have been less successful in reaching a consensus on how to dispose of the billions of curies of fission products and transuranics resulting from nuclear weapons testing, electrical power generation, medical research, and a variety of other human endeavors. Many countries, including the United States, favor underground burial as a means of disposing of radioactive wastes. There are, however, serious questions about how such buried wastes may behave in the underground environment and particularly how they might eventually contaminate water, air and soil resources on which we are dependent. This paper describes research done in the United States in the state of Nevada on the behavior of radioactive materials placed underground. During the last thirty years, a series of ''experiments'' conducted for other purposes (testing of nuclear weapons) have resulted in a wide variety of fission products and actinides being injected in rock strata both above and below the water table. Variables which seem to control the movement of these radionuclides include the physical form (occlusion versus surface deposition), the chemical oxidation state, sorption by mineral phases of the host rock, and the hydrologic properties of the medium. The information gained from these studies should be relevant to planning for remediation of nuclear facilities elsewhere in the world and for long-term storage of nuclear wastes

  4. Radionuclide transverse section imager

    International Nuclear Information System (INIS)

    Stoddart, H.F.

    1980-01-01

    A radioisotope scanning apparatus for use in nuclear medicine is described in detail. The apparatus enables the quantification and spatial location of the radioactivity in a body section of a patient to be determined with high sensitivity. It consists of an array of highly focussed collimators arranged such that adjacent collimators move in the same circumferential but opposite radial directions. The explicit movements of the gantry are described in detail and may be controlled by a general purpose computer. The use of highly focussed collimators allows both a reasonable solid angle of acceptance and also high target to background images; additionally, dual radionuclide pharmaceutical studies can be performed simultaneously. It is claimed that the high sensitivity of the system permits the early diagnosis of pathological changes and the images obtained show accurately the location and shape of physiological abnormalities. (UK)

  5. Radioactivity, radionuclides, radiation

    CERN Document Server

    Magill, Joseph

    2005-01-01

    RADIOACTIVITY – RADIONUCLIDES – RADIATION is suitable for a general audience interested in topical environmental and human health radiological issues such as radiation exposure in aircraft, food sterilisation, nuclear medicine, radon gas, radiation dispersion devices ("dirty bombs")… It leads the interested reader through the three Rs of nuclear science, to the forefront of research and developments in the field. The book is also suitable for students and professionals in the related disciplines of nuclear and radiochemistry, health physics, environmental sciences, nuclear and astrophysics. Recent developments in the areas of exotic decay modes (bound beta decay of ‘bare’ or fully ionized nuclei), laser transmutation, nuclear forensics, radiation hormesis and the LNT hypothesis are covered. Atomic mass data for over 3000 nuclides from the most recent (2003) evaluation are included.

  6. Deep sea radionuclides

    International Nuclear Information System (INIS)

    Kanisch, G.; Vobach, M.

    1993-01-01

    Every year since 1979, either in sping or in summer, the fishing research vessel 'Walther Herwig' goes to the North Atlantic disposal areas of solid radioactive wastes, and, for comparative purposes, to other areas, in order to collect water samples, plankton and nekton, and, from the deep sea bed, sediment samples and benthos organisms. In addition to data on the radionuclide contents of various media, information about the plankton, nekton and benthos organisms living in those areas and about their biomasses could be gathered. The investigations are aimed at acquiring scientifically founded knowledge of the uptake of radioactive substances by microorganisms, and their migration from the sea bottom to the areas used by man. (orig.) [de

  7. Radionuclide reporter gene imaging

    International Nuclear Information System (INIS)

    Min, Jung Joon

    2004-01-01

    Recent progress in the development of non-invasive imaging technologies continues to strengthen the role of molecular imaging biological research. These tools have been validated recently in variety of research models, and have been shown to provide continuous quantitative monitoring of the location(s), magnitude, and time-variation of gene expression. This article reviews the principles, characteristics, categories and the use of radionuclide reporter gene imaging technologies as they have been used in imaging cell trafficking, imaging gene therapy, imaging endogenous gene expression and imaging molecular interactions. The studies published to date demonstrate that reporter gene imaging technologies will help to accelerate model validation as well as allow for clinical monitoring of human diseases

  8. Radionuclide reporter gene imaging

    Energy Technology Data Exchange (ETDEWEB)

    Min, Jung Joon [School of Medicine, Chonnam National Univ., Gwangju (Korea, Republic of)

    2004-04-01

    Recent progress in the development of non-invasive imaging technologies continues to strengthen the role of molecular imaging biological research. These tools have been validated recently in variety of research models, and have been shown to provide continuous quantitative monitoring of the location(s), magnitude, and time-variation of gene expression. This article reviews the principles, characteristics, categories and the use of radionuclide reporter gene imaging technologies as they have been used in imaging cell trafficking, imaging gene therapy, imaging endogenous gene expression and imaging molecular interactions. The studies published to date demonstrate that reporter gene imaging technologies will help to accelerate model validation as well as allow for clinical monitoring of human diseases.

  9. Natural radionuclides in groundwaters

    International Nuclear Information System (INIS)

    Laul, J.C.

    1990-01-01

    The U-234 and Th-230 radionuclides are highly retarded by factors of 10 4 to 10 5 in basalt groundwater (Hanford) and briny groundwaters from Texas and geothermal brine from the Salton Sea Geothermal Field (SSGF). In basalt groundwaters (low ionic strength), Ra is highly sorbed, while in brines (high ionic strength), Ra is soluble. This is probably because the sorption sites are saturated with Na + and Cl - ions and RaCl 2 is soluble in brines. Pb-210 is soluble in SSGF brine, probably as a chloride complex. The U-234/Th-230 ratios in basalt groundwaters and brines from Texas and SSGF are nearly unity, indicating that U is in the +4 state, suggesting a reducing environment for these aquifers. 19 refs., 3 figs

  10. Natural radionuclides in groundwaters

    International Nuclear Information System (INIS)

    Laul, J.C.

    1992-01-01

    The 234 U and 230 Th radionuclides are highly retarded by factors of 10 4 to 10 5 in basalt groundwater (Hanford) and briny groundwaters from Texas, and geothermal brine form the Salton Sea Geothermal Field (SSGF). In basalt groundwaters (low ionic strength), Ra is highly sorbed, while in brines (high ionic strength), Ra is soluble. This is probably because the sorption sites are saturated with Na + and Cl - ions, and RaCl 2 is soluble in brines. 210 Pb is soluble in SSGF brine, probably as a chloride complex. The 234 U/ 230 Th ratios in basalt groundwaters and brines from Texas and SSGF are nearly unity, indicating that U is in the +4 state, suggesting a reducing environment for these aquifers. (author) 19 refs.; 3 figs

  11. Combining of radionuclides with constituent materials of marine algae

    International Nuclear Information System (INIS)

    Nakamura, Ryoichi; Nakahara, Motokazu; Ishii, Toshiaki; Ueda, Taishi; Shimizu, Chiaki.

    1979-01-01

    The relations between the accumulation-elimination of radionuclides and the constituent materials of marine algae were studied to determine more precisely the mechanism of the radioactive contamination of marine organisms. This will increase the information about the behavior of radionuclides in marine organisms in relation to the environmental conditions (temperature, physico-chemical state of radioisotope, and so on) and the biological conditions (feeding habits, species, and so on). Eisenia contaminated by 137 Cs and 106 Ru- 106 Rh was fractionated by solvent extraction into 6 fractions. The largest portion of 137 Cs was in the boiling water fraction; 106 Ru- 106 Rh was most extracted by 24% KOH solution. Elution patterns by Sephadex G-100 gel-filtration of samples differed largely from each other, both among the 3 kinds of radionuclides and between the 2 species of the algae. Therefore, the accumulation of the radionuclides by the marine algae was proved to be not only due to a physical absorption to the surface of the algae but also to the biological combining of the radionuclides with the constituents of the algae. Furthermore, it was found that radionuclides which combine with a few constituents of alga are not eliminated equally. This is considered to be useful for the physiological analysis of elimination curves. (author)

  12. Significant Radionuclides Determination

    Energy Technology Data Exchange (ETDEWEB)

    Jo A. Ziegler

    2001-07-31

    The purpose of this calculation is to identify radionuclides that are significant to offsite doses from potential preclosure events for spent nuclear fuel (SNF) and high-level radioactive waste expected to be received at the potential Monitored Geologic Repository (MGR). In this calculation, high-level radioactive waste is included in references to DOE SNF. A previous document, ''DOE SNF DBE Offsite Dose Calculations'' (CRWMS M&O 1999b), calculated the source terms and offsite doses for Department of Energy (DOE) and Naval SNF for use in design basis event analyses. This calculation reproduces only DOE SNF work (i.e., no naval SNF work is included in this calculation) created in ''DOE SNF DBE Offsite Dose Calculations'' and expands the calculation to include DOE SNF expected to produce a high dose consequence (even though the quantity of the SNF is expected to be small) and SNF owned by commercial nuclear power producers. The calculation does not address any specific off-normal/DBE event scenarios for receiving, handling, or packaging of SNF. The results of this calculation are developed for comparative analysis to establish the important radionuclides and do not represent the final source terms to be used for license application. This calculation will be used as input to preclosure safety analyses and is performed in accordance with procedure AP-3.12Q, ''Calculations'', and is subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (DOE 2000) as determined by the activity evaluation contained in ''Technical Work Plan for: Preclosure Safety Analysis, TWP-MGR-SE-000010'' (CRWMS M&O 2000b) in accordance with procedure AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities''.

  13. Radionuclide calibrators performance evaluation

    International Nuclear Information System (INIS)

    Mora Ramirez, E.; Zeledon Fonseca, P.; Jimenez Cordero, M.

    2008-01-01

    Radionuclide calibrators are used to estimate accurately activity prior to administration to a patient, so it is very important that this equipment meets its performance requirements. The purpose of this paper is to compare the commercially available 'Calicheck' (Calcorp. Inc), used to assess linearity, versus the well-known source decay method, and also to show our results after performing several recommended quality control tests. The parameters that we wanted to evaluate were carried on using the Capintec CRC-15R and CRC-15 β radionuclide calibrators. The evaluated tests were: high voltage, display, zero adjust, background, reproducibility, source constancy, accuracy, precision and linearity. The first six tests were evaluated on the daily practice, here we analyzed the 2007 recorded data; and the last three were evaluated once a year. During the daily evaluation both calibrators performance were satisfactory comparing with the manufacture's requirements. The accuracy test show result within the ± 10% allowed for a field instrument. Precision performance is within the ± 1 % allowed. On the other hand, the linearity test shows that using the source decay method the relative coefficient is 0.9998, for both equipment and using the Calicheck the relative coefficient is 0.997. However, looking the percentage of error, during the 'Calicheck' test, its range goes from 0.0 % up to -25.35%, and using the source decay method, the range goes from 0.0 % up to -31.05 %, taking into account both instruments. Checking the 'Calicheck' results we can see that the results varying randomly, but using the source decay method the percentage of error increase as the source activity decrease. We conclude that both devices meet its manufactures requirements, in the case of the linearity using the decay method, decreasing the activity source, increasing the percentage of error, this may happen because of the equipment age. (author)

  14. Radionuclide Incorporation and Long Term Performance of Apatite Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jianwei [Louisiana State Univ., Baton Rouge, LA (United States); Lian, Jie [Rensselaer Polytechnic Inst., Troy, NY (United States); Gao, Fei [Univ. of Michigan, Ann Arbor, MI (United States)

    2016-01-04

    This project aims to combines state-of-the-art experimental and characterization techniques with atomistic simulations based on density functional theory (DFT) and molecular dynamics (MD) simulations. With an initial focus on long-lived I-129 and other radionuclides such as Cs, Sr in apatite structure, specific research objectives include the atomic scale understanding of: (1) incorporation behavior of the radionuclides and their effects on the crystal chemistry and phase stability; (2) stability and microstructure evolution of designed waste forms under coupled temperature and radiation environments; (3) incorporation and migration energetics of radionuclides and release behaviors as probed by DFT and molecular dynamics (MD) simulations; and (4) chemical durability as measured in dissolution experiments for long term performance evaluation and model validation.

  15. 5-7 Year Old Children's Conceptions of Behaving Artifacts and the Influence of Constructing Their Behavior on the Development of Theory of Mind (ToM and Theory of Artificial Mind (ToAM

    Directory of Open Access Journals (Sweden)

    Karen Spektor-Precel

    2015-12-01

    Full Text Available Nowadays, we are surrounded by artifacts that are capable of adaptive behavior, such as electric pots, boiler timers, automatic doors, and robots. The literature concerning human beings’ conceptions of “traditional” artifacts is vast, however, little is known about our conceptions of behaving artifacts, nor of the influence of the interaction with such artifacts on cognitive development, especially among children. Since these artifacts are provided with an artificial “mind,” it is of interest to assess whether and how children develop a Theory of Artificial Mind (ToAM which is distinct from their Theory of Mind (ToM. The study examined a new theoretical scheme named ToAM (Theory of Artificial Mind by means of qualitative and quantitative methodology among twenty four 5-7 year old children from central Israel. It also examined the effects of interacting with behaving artifacts (constructing versus observing the robot’s behavior using the “RoboGan” interface on children’s development of ToAM and their ToM and looked for conceptions that evolve among children while interacting with behaving artifacts which are indicative of the acquisition of ToAM. In the quantitative analysis it was found that the interaction with behaving artifacts, whether as observers or constructors and for both age groups, brought into awareness children’s ToM as well as influenced their ability to understand that robots can behave independently and based on external and environmental conditions. In the qualitative analysis it was found that participating in the intervention influenced the children’s ToAM for both constructors and for the younger observer. Engaging in building the robot’s behavior influenced the children’s ability to explain several of the robots’ behaviors, their understanding of the robot’s script-based behavior and rule-based behavior and the children’s metacognitive development. The theoretical and practical importance of

  16. Vertical soil migration of radionuclide fallout from the Chernobyl' accident

    International Nuclear Information System (INIS)

    Silant'ev, A.N.; Shkuratova, I.G.; Bobovnikova, T.I.

    1989-01-01

    The most suitable model for describing the behavior of radionuclide fallout on a soil surface is quasidiffusion transfer with directional transfer taken into account. The parameter values for this have been determined previously and are supplemented by the results of this work. To investigate the initial radionuclide distribution along the soil profile, monolithic soil samples 5 cm thick were taken in June-September 1986 in areas which had been subjected to contamination due to the Chernobyl' accident. The samples taken were cut up into layers. The first layer, 0.5 cm thick, was cut off from the surface of the soil monolith together with the grass. The next layer cut off was also 0.5 cm thick. Then two layers, each 1 cm in thickness, were cut off. The thickness of the last layer was 2 cm. The vertical distribution of radionuclides along the soil profile which was examined may be called the initial distribution, which will then change due to nonimmediate migration of radionuclides in the soil. Based on the research which has been performed, the following conclusions may be drawn. One portion of the radionuclides resulting from fallout is trapped by plant cover, while the other enters immediately into the soil. For a thick plant covering, about 80% of the radionuclide fallout is sorbed by the grass; for sparse cover, about 40%. The radionuclides entering the soil along with rainwater penetrate into the soil depths, producing contamination which falls off exponentially with depth. The exponent index is close to 1 cm -1 . In a forest, the main amount of radionuclide fallout is trapped by litter. Approximately 10% of the contamination fallout penetrates beneath the litter

  17. An experimental study on the application of radionuclide imaging in repair of the bone defect

    Directory of Open Access Journals (Sweden)

    Weimin Zhu

    2011-08-01

    Full Text Available The aim of our study was to validate the effect of radionuclide imaging in early monitoring of the bone’s reconstruction, the animal model of bone defect was made on the rabbits repaired with HA artificial bone. The ability of bone defect repair was evaluated by using radionuclide bone imaging at 2, 4, 8 and 12 weeks postoperatively. The results indicate that the experimental group stimulated more bone formation than that of the control group. The differences of the bone reconstruction ability were statistically significant (p<0.05. The nano-HA artificial has good bone conduction, and it can be used for the treatment of bone defects. Radionuclide imaging may be an effective and first choice method for the early monitoring of the bone’s reconstruction.

  18. Uptake of radionuclides by farm animals close to a major nuclear installation

    International Nuclear Information System (INIS)

    Sumerling, T.J.; Green, N.; Dodd, N.J.

    1984-01-01

    A field investigation of the transfer of artificially produced radionuclides in the pasture-cow-milk pathway has been made at a farm close to the nuclear fuel reprocessing installation at Sellafield. The routine discharges from the plant have resulted in enhanced levels of several artificial radionuclides in the local environment. The annual depositions of 90 Sr and 137 Cs at the farm were a factor of about five higher than the average deposition of these radionuclides in the UK. Even if extremely cautious assumptions concerning local eating habits are made, the consumption of meat and dairy products from this farm would give rise to an annual activity intake of less than one percent of the limit for adult members of the public. (orig./HP)

  19. Report on the intercomparison run IAEA-306 radionuclides in Baltic Sea sediment

    International Nuclear Information System (INIS)

    Ballestra, S.; Vas, D.; Lopez, J.J.; Noshkin, V.

    1989-10-01

    The results of an intercomparison exercise on a Baltic Sea sediment sample, coded as IAEA-306, designed for the determination of artificial and natural radionuclide levels, are reported. This sample was collected in the fall 1986. It was anticipated that the concentrations of the artificial radionuclides in this sediment would be higher than the environmental levels usually found and, therefore, would constitute an excellent intercomparison sample. The data from 84 laboratories representing 34 countries have been evaluated. The most frequently measured radionuclides are: 90 Sr, 125 Sb, 134 Cs, 137 Cs, 238 Pu, 239+240 Pu, 241 Am, 40 K, 210 Pb- 210 Po, 226 Ra, 228 Ra, 228 Th, 230 Th, 232 Th, 234 U and 238 U. 6 refs, 13 tabs

  20. A study on the characteristics of colloid-associated radionuclide transport in porous media

    International Nuclear Information System (INIS)

    Jeong, Yun Chang

    1997-02-01

    Recently, the radionuclide transport in the form of colloids has been focused intensively in the safety assessment of a radioactive waste repository. As colloids are considered to be able to increase the transport rate of radionuclide through geologic media, the transport of radionuclide should be adjusted by the presence of colloids. The migration of dissolved radionuclide is expected to depend on various process such as advection, dispersion and interactions with soils, and, in addition, the transport of colloid-mediated radionuclide is considered to be more complicated because of the interactions between radionuclides and colloids. In this paper the migration behavior of colloid-associated radionuclides within subsurface are reviewed and studied in detail. The colloid-mediated transport system was modelled and simulated in order to illustrate the effects of colloids on the transport of radionuclide in the aquifer system. The transport rate of radionuclide is mainly controlled by a retardation factor which is controlled by colloidal behaviors, degree of adsorption, and the related geologic parameters. Therefore it is necessary to carefully understand the accelerating tendency of the retardation difference factor, and in this study the trends are analyzed, described and the retardation difference factor is mathematically defined, simplified and applied practically to the safety and performance assessment of a future repository

  1. Elimination of radionuclides and heavy metals from soils

    International Nuclear Information System (INIS)

    Navarcik, I.; Cipakova, A.; Palagyl, S.

    1994-01-01

    Sorption and desorption of radionuclides and heavy metals, their vertical migration and gradual extraction from soils were studied. Tessier sequential extraction method was used for determination the physicochemical forms of radionuclides and heavy metals absorbed by root system of plants and leached into ground water. Fixed forms of heavy metals and radionuclides are prevailing in soils. As to artificial ( 90 Sr, 137 Cs) isotope ratio of fixed forms bound with soil components, it is higher for 137 Cs (black earth - 95%, sandy soil - 62%) as compared to 90 Sr. Mobilization procedures for elimination of unfavourable influence of these pollutants in soils were used. The bacteria Pseudomonas sp. and Micrococcus l. are applied for this purpose. At the same time the growing of technical plants (Linum usitatissimum L. and Brassica napus L. var.) was studied as a method for mobilizing the heavy metals and radionuclides from soils. Retardation influence of bacteria on 85 Sr was noticed after as much as 3 months. The sum of water-soluble and exchangeable fractions reached 60%. Values of Cs distribution proved that microorganisms or plants used had no appreciable influence on Cs-mobility. After 3 months the relative ratio of accessible fraction increased with about 5%. As to heavy metals, both bacteria and plant growing influenced their retardation. In the case of Cd, one month operation of microorganisms resulted in important increase of easily available Cd-ratio (about 25%) in soils. (author)

  2. Radionuclides in Canada goose eggs

    International Nuclear Information System (INIS)

    Rickard, W.H.; Sweany, H.A.

    1975-01-01

    Low levels of radionuclides were measured in Canada goose eggs taken from deserted nests from Columbia River islands on the Energy Research and Development Administration's Hanford Reservation. Potassium-40, a naturally occurring radionuclide, was the most abundant radionuclide measured in egg contents and egg shell. Strontium-90 was incorporated into egg shells and cesium-137 into inner egg contents. Manganese-54, cobalt-60, and zinc-65 were more abundant in inner egg contents than in egg shell. Cerium-144 was detected in egg shell but not in inner shell

  3. Radionuclide migration in water reservoirs

    International Nuclear Information System (INIS)

    Rodionova, L.F.

    1983-01-01

    Toxicity degree and radiation effect of different radionuclides depend on multiple factors, whose interaction can strengthen or weaken the effects through the mechanism of nuclide accumulation by hydrobiontes. Stage of development of an aquatic organism, its age, mass and sex as well as lifetime and residence time of the organism in the given medium are of importance. The radionuclide build up depends on illumination, locale of the bioobject residence, on the residence nature. The concentration of radionuclides in aquatic organisms and bionts survival depend on a season, temperature of the residence medium, as well as salinity and mineral composition of water influence

  4. National Low-Level Waste Management Program Radionuclide Report Series

    International Nuclear Information System (INIS)

    Rudin, M.J.; Stanton, C.; Patterson, R.G.; Garcia, R.S.

    1992-02-01

    This report, Volume 2 of the National Low-Level Radioactive Waste Management Program Radionuclide Report Series, discusses radiological and chemical characteristics of technetium-99. This report also includes discussions about waste streams in which technetium-99 can be found, waste forms that contain technetium-99, and technetium-99's behavior in the environment and in the human body

  5. National Low-Level Waste Management Program Radionuclide Report Series

    International Nuclear Information System (INIS)

    Rudin, M.J.; Garcia, R.S.

    1992-02-01

    This report, Volume 3 of the National Low-Level Radioactive Waste Management Program Radionuclide Report Series, discusses the radiological and chemical characteristics of carbon-14. The report also discusses waste streams that contain carbon-14, waste forms that contain carbon-14, and carbon-14 behavior in the environment and in the human body

  6. Intercomparison of radionuclide measurements in marine sediment sample IAEA-367

    Energy Technology Data Exchange (ETDEWEB)

    Ballestra, S; Lopez, J J; Gastaud, J; Vas, D; Noshkin, V

    1991-08-01

    The results of an intercomparison exercise on a Pacific Ocean sediment sample, IAEA-367, designed for the determination of artificial and natural radionuclides levels, are reported. The data from 81 laboratories representing 37 countries have been evaluated. The following are the recommended values, with confidence intervals, for {sup 60}Co, {sup 90}Sr, {sup 137}Cs, {sup 239+240}Pu (Reference date: 1 January 1990). Information values for {sup 155}Eu, {sup 238}Pu, {sup 241}Am, and {sup 241}Pu are reported. Information values for the following natural radionuclides {sup 40}K, {sup 226}Ra, {sup 228}Th, {sup 230}Th, {sup 234}U, {sup 235}U and {sup 238}U are also reported. (author)

  7. The introduction of radionuclides over the atmosphere into the North Sea

    International Nuclear Information System (INIS)

    Kautsky, H.

    1983-01-01

    Although it is barely possible to provide exact data concerning the aerosol entry and the quantities of precipitation in the region of the North Sea, an attempt will be made to estimate the annual entry of radionuclides in the North Sea. As data for the calculations, available estimations of the quantity of precipitation over the sea, the content of radionuclides in the air and in the rain over land and the activities conveyed thereby to the earth, as well as the emission quantities of radionuclides with the exhaust air from nuclear power plants, are applied. It is quite clear that Tritium represents by far the main part of the radionuclides which enter the sea via precipitation. The majority of the other artificial radio nuclides, on the other hand, are to be viewed as being quantitatively insignificant. (orig./HP) [de

  8. Natural radionuclides in an eucalyptus forest located in the south of Spain

    International Nuclear Information System (INIS)

    Vaca, F.; Manjon, G.; Garcia-Leon, M.

    2001-01-01

    Eucalyptus forests can be considered as the main source of raw material for the pulp industry of Spain. This environment was selected for a radioactivity study because natural and artificial radionuclides can be transferred into the pulp mills, associated with raw material, wood and barks, where they are concentrated by industrial processes, becoming a cause of doses. Radionuclide concentration of natural radionuclides ( 238 U, 234 U, 228 Th, 230 Th, 232 Th) were determined by alpha- and gamma-spectrometry. Well-established radiochemical procedures were applied to environmental samples in order to isolate these radionuclides. A comparison between 228 Th activity, determined by gamma-spectrometry, and 232 Th activity, determined by alpha-spectrometry, was used as quality control parameter for analyses. The concentration factors were finally evaluated from experimental data.

  9. Dynamic cardiomyoplasty using artificial muscle.

    Science.gov (United States)

    Suzuki, Yasuyuki; Daitoku, Kazuyuki; Minakawa, Masahito; Fukui, Kozo; Fukuda, Ikuo

    2008-01-01

    Dynamic cardiomyoplasty using latissimus dorsi muscle was previously used to compensate for congestive heart failure. Now, however, this method is not acceptable because the long-term result was not as expected owing to fatigue of the skeletal muscle. BioMetal fiber developed by Toki Corporation is one of the artificial muscles activated by electric current. The behavior of this fiber is similar to that of organic muscle. We made an artificial muscle like the latissimus dorsi using BioMetal fiber and tested whether we could use this new muscle as a cardiac supporting device. Testing one Biometal fiber showed the following performance: practical use maximal generative force was 30 g, exercise variation was 50%, and the standard driving current was 220 mA. We created a 4 x 12-cm tabular artificial muscle using 8 BioMetal fibers as a cardiac support device. We also made a simulation circuit composed of a 6 x 8-cm soft bag with unidirectional valves, reservoir, and connecting tube. The simulation circuit was filled with water and the soft bag was wrapped with the artificial muscle device. After powering the device electrically at 9 V with a current of 220 mA for each fiber, we measured the inside pressure and observed the movement of the artificial device. The artificial muscle contracted in 0.5 s for peak time and squeezed the soft bag. The peak pressure inside the soft bag was measured as 10 mmHg. Although further work will be needed to enhance the speed of deformability and movement simulating contraction, we conclude that artificial muscle may be potentially useful as a cardiac assistance device that can be developed for dynamic cardiomyoplasty.

  10. Radionuclide methods in pediatric cardiology

    International Nuclear Information System (INIS)

    Reich, O.; Ruth, C.; Samanek, M.

    1990-01-01

    The use of radionuclide methods in pediatric cardiology is discussed for non-invasive evaluation of myocardial function and perfusion, regional lung perfusion and ventilation, and for measuring central and peripheral hemodynamics. (H.W.). 16 refs

  11. Radionuclide Retention in Concrete Wasteforms

    Energy Technology Data Exchange (ETDEWEB)

    Bovaird, Chase C.; Jansik, Danielle P.; Wellman, Dawn M.; Wood, Marcus I.

    2011-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. The information present in the report provides data that (1) measures the effect of concrete wasteform properties likely to influence radionuclide migration; and (2) quantifies the rate of carbonation of concrete materials in a simulated vadose zone repository.

  12. Radionuclides in the food chain

    International Nuclear Information System (INIS)

    Harley, J.H.; Schmidt, G.D.

    1988-01-01

    Radionuclides in the Food Chain reviews past experience in meeting the challenge of radionuclide contamination of foodstuffs and water sources and, in the wake of the reactor accidents at Chernobyl and Three Mile Island, presents current concepts and programs relating to measurement, surveillance, effects, risk management, evaluation guidelines, and control and regulatory activities. This volume, based on a symposium sponsored by the International Life Sciences Institute in association with the International Institute for Applied Systems Analysis, which brought together both radiation experts and food industry policymakers, examines such vital topics as structural problems in large-scale crisis-managment systems; dose assessment from man-made sources; international recommendations on radiation protection; airborne contamination, as well as aquatic and soilborne radionuclides; food-chain contamination from testing nuclear devices; long-term health effects of radionuclides in food and water supplies; and use of mathematical models in risk assessment and management. (orig.)

  13. Surface diffusion of sorbed radionuclides

    International Nuclear Information System (INIS)

    Berry, J.A.; Bond, K.A.

    1991-01-01

    Surface diffusion has in the past been invoked to explain rates of radionuclide migration which were greater than those predicted. Results were generally open to interpretation but the possible existence of surface diffusion, whereby sorbed radionuclides could potentially migrate at much enhanced rates, necessitated investigation. In this work through-diffusion experiments have shown that although surface diffusion does exist for some nuclides, the magnitude of the phenomenon is not sufficient to affect repository safety assessment modelling. (author)

  14. Radionuclide generators for biomedical applications

    International Nuclear Information System (INIS)

    Finn, R.D.; Molinski, V.J.; Hupf, H.B.; Kramer, H.

    1983-10-01

    This document reviews the chemical literature of those radionuclide generators that have gained or appear to possess utility in medical imaging. The text represents a conscientious effort to peruse the scientific literature through 1980. The intent of this work is to provide a reference point for the investigator who is interested in the development of a particular generator system and the refinements which have been reported. Moreover, the incorporation of the particular daughter radionuclide into a suitable radiodiagnostic agent is presented

  15. Radionuclide migration in soils

    Energy Technology Data Exchange (ETDEWEB)

    Demir, M [Ingenieurgesellschaft Bonnenberg und Drescher, Juelich (Germany, F.R.)

    1979-01-01

    Unplanned releases from a nuclear installation - e.g., leakage from a storage tank or other incident - can result in the escape of contaminants such as U, Pu, Cs, Sr, T etc. Nuclide transport through the ground is governed by characteristics of the subsurface hydrology and the specific nuclides under consideration. Unsaturated soil layers result in a transport rate so low as to negligible. Radionuclides reaching the ground water are assumed to endanger human life because of potential uncontrolled ingestion. The most dangerous nuclides are long-lived and not absorbed, or very poorly absorbed, in the soil. During migration of nuclides through saturated soil layers, the concentration can be reduced by dilution. Preliminary results indicate that tritium is spread with ground water velocity. Its concentration can be reduced only by diffusion, dispersion and radioactive decay. Alpha-emitters are strongly retained velocities of alpha-emitters are approximately one thousandth (10/sup -3/) that of T. Transport velocities of Cs and Sr are approximately one hundreth (10/sup -2/) and one tenth (10/sup -1/) that of T respectively.

  16. Radionuclide migration in soils

    International Nuclear Information System (INIS)

    Demir, M.

    1979-01-01

    Unplanned releases from a nuclear installation - e.g., leakage from a storage tank or other incident - can result in the escape of contaminants such as U, Pu, Cs, Sr, T etc. Nuclide transport through the ground is governed by characteristics of the subsurface hydrology and the specific nuclides under consideration. Unsaturated soil layers result in a transport rate so low as to negligible. Radionuclides reaching the ground water are assumed to endanger human life because of potential uncontrolled ingestion. The most dangerous nuclides are long-lived and not absorbed, or very poorly absorbed, in the soil. During migration of nuclides through saturated soil layers, the concentration can be reduced by dilution. Preliminary results indicate that tritium is spread with ground water velocity. Its concentration can be reduced only by diffusion, dispersion and radioactive decay. Alpha-emitters are strongly retained velocities of alpha-emitters are approximately one thousandth (10 -3 ) that of T. Transport velocities of Cs and Sr are approximately one hundreth (10 -2 ) and one tenth (10 -1 ) that of T respectively. (orig./HP) [de

  17. Radionuclide salivary gland imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mishkin, F.S.

    1981-10-01

    Salivary gland imaging with 99mTc as pertechnetate provides functional information concerning trapping and excretion of the parotid and submandibular glands. Anatomic information gained often adds little to clinical evaluation. On the other hand, functional information may detect subclinical involvement, which correlates well with biopsy of the minor labial salivary glands. Salivary gland abnormalities in systemic disease such as sarcoidosis, rheumatoid arthritis, lupus erythematosus, and other collagenvascular disorders may be detected before they result in the clinical manifestaions of Sjoegren's syndrome. Such glands, after initially demonstrating increased trapping in the acute phase, tend to have decreased trapping and failure to discharge pertechnetate in response to an appropriate physiologic stimulus. Increased uptake of gallium-67 citrate often accompanies these findings. Inflammatory parotitis can be suspected when increased perfusion is evident on radionuclide angiography with any agent. The ability of the salivary gland image to detect and categorize mass lesions, which result in focal areas of diminished activity such as tumors, cysts, and most other masses, is disappointing, while its ability to detect and categorize Warthin's tumor, which concentrates pertechnetate, is much more valuable, although not specific.

  18. Radionuclide brain scanning

    International Nuclear Information System (INIS)

    Abdel-Dayem, H.

    1992-01-01

    At one stage of medical imaging development, radionuclide brain scanning was the only technique available for imaging of the brain. Advent of CT and MRI pushed it to the background. It regained some of the grounds lost to ''allied advances'' with the introduction of brain perfusion radiopharmaceuticals. Positron emission tomography is a promising functional imaging modality that at present will remain as a research tool in special centres in developed countries. However, clinically useful developments will gradually percolate from PET to SPECT. The non-nuclear imaging methods are totally instrument dependent; they are somewhat like escalators, which can go that far and no further. Nuclear imaging has an unlimited scope for advance because of the new developments in radiopharmaceuticals. As the introduction of a radiopharmaceutical is less costly than buying new instruments, the recent advances in nuclear imaging are gradually perfusing through the developing countries also. Therefore, it is essential to follow very closely PET developments because what is research today might become routine tomorrow

  19. Radionuclides migration or isolation?

    International Nuclear Information System (INIS)

    Toulhoat, P.; Grambow, B.; Simoni, E.

    2005-01-01

    After 20 years of research, the chemical behaviour of actinides and fission products in nuclear waste disposal environments is much better understood. Consistent thermodynamic data have been gathered and allow much more accurate previsions. Through the considerable development of analytical spectroscopy, including time resolved laser fluorescence and X ray absorption, a better understanding of the chemical reactivity (complexation, sorption) of actinides and fission products at a molecular scale has been possible. Chemically reducing conditions are found in most selected disposal host rock formations, generally chosen for their high sorption capacity (clays); such conditions favour the chemical confinement of most radionuclides through precipitation or sorption. Low permeability host rocks participate to this confinement, as convective fluxes are lower than diffusive fluxes. The most recent performance assessment exercises have taken into account the recent progress of knowledge in the chemical evolution of the near field. They show that the dose rates at the outlet are far lower than existing recommendations for normal and most altered evolution scenarios. (authors)

  20. Radionuclide salivary gland imaging

    International Nuclear Information System (INIS)

    Mishkin, F.S.

    1981-01-01

    Salivary gland imaging with 99mTc as pertechnetate provides functional information concerning trapping and excretion of the parotid and submandibular glands. Anatomic information gained often adds little to clinical evaluation. On the other hand, functional information may detect subclinical involvement, which correlates well with biopsy of the minor labial salivary glands. Salivary gland abnormalities in systemic disease such as sarcoidosis, rheumatoid arthritis, lupus erythematosus, and other collagenvascular disorders may be detected before they result in the clinical manifestaions of Sjoegren's syndrome. Such glands, after initially demonstrating increased trapping in the acute phase, tend to have decreased trapping and failure to discharge pertechnetate in response to an appropriate physiologic stimulus. Increased uptake of gallium-67 citrate often accompanies these findings. Inflammatory parotitis can be suspected when increased perfusion is evident on radionuclide angiography with any agent. The ability of the salivary gland image to detect and categorize mass lesions, which result in focal areas of diminished activity such as tumors, cysts, and most other masses, is disappointing, while its ability to detect and categorize Warthin's tumor, which concentrates pertechnetate, is much more valuable, although not specific

  1. Radionuclide brain scanning

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Dayem, H

    1993-12-31

    At one stage of medical imaging development, radionuclide brain scanning was the only technique available for imaging of the brain. Advent of CT and MRI pushed it to the background. It regained some of the grounds lost to ``allied advances`` with the introduction of brain perfusion radiopharmaceuticals. Positron emission tomography is a promising functional imaging modality that at present will remain as a research tool in special centres in developed countries. However, clinically useful developments will gradually percolate from PET to SPECT. The non-nuclear imaging methods are totally instrument dependent; they are somewhat like escalators, which can go that far and no further. Nuclear imaging has an unlimited scope for advance because of the new developments in radiopharmaceuticals. As the introduction of a radiopharmaceutical is less costly than buying new instruments, the recent advances in nuclear imaging are gradually perfusing through the developing countries also. Therefore, it is essential to follow very closely PET developments because what is research today might become routine tomorrow

  2. [Radionuclides in siberian Thymallus from radiation-contaminated area in the middle stream of the Yenisei River].

    Science.gov (United States)

    Zotina, T A; Trofimova, E A; Bolsunovskiĭ, A Ia

    2012-01-01

    Concentration of artificial radionuclides in bodies of arctic grayling from the radioactively contaminated zone of the Yenisei River in the vicinity of the Mining-and-Chemical Combine of Rosatom was investigated in 2007-2010. Gamma-spectrometric analysis revealed artificial radionuclides in all the organs and tissues of fish. The isotope composition was the most diverse (60Co, 65Zn, 85Sr, 99Mo, 106Ru, 137Cs, 144Ce) in internal organs of grayling. The activity of radionuclides increased in internal organs including liver and kidney and in the content of digestive tract of grayling during winter and spring, which coincided with the change in the feeding spectrum of grayling. The trophic transfer factor of radionuclides from zoobenthos (Philolimnogammarus spp.) to whole bodies and muscles of grayling was over 1 (1.8-2.4) only for natural radionuclide 40K. The trophic transfer of artificial radionuclides (60Co, 65Zn, 137Cs) to muscles and bodies of grayling was one-two orders of magnitude less effective.

  3. Study on natural radionuclide activities in meat samples consumed in Sao Paulo City, Brazil

    International Nuclear Information System (INIS)

    Rosa, Mychelle M.L.; Taddei, Maria HelenaT.

    2015-01-01

    Consumption of food is usually the most important route by which natural and artificial radionuclides can enter the human body. An assessment of radionuclide levels in different foods and diets is therefore important to estimate the intake of these radionuclides by man. The contamination by radionuclides can occur via the food chain (soil, root, plant and animal), with emphasis to the long half-life radionuclides, which can also have their transfer through the animal meat. The inclusion of meat in human nutrition is important because it is an excellent source of high quality protein, nutrient related to construction and cell regeneration. This work aims the determination of natural radionuclides ( 234 U, 235 U, 238 U, 228 Th, 230 Th, 232 Th, 226 Ra, 228 Ra, and 210 Pb) in meat samples. Five groups of samples were analyzed, such as cattle meat (beef), fish, pork, poultry, and processed meat, after radiochemical separation followed by alpha or alpha beta spectrophotometry, and total count quantification. The determination of these radionuclides is very important because they are products of the natural decay series of 238 U and 232 Th, being easily found in meat samples. (author)

  4. Study on natural radionuclide activities in meat samples consumed in Sao Paulo City, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Mychelle M.L.; Taddei, Maria HelenaT. [Comissao Nacional de Energia Nuclear (LAPOC/CNEN), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Avegliano, Roseane P.; Maihara, Vera A., E-mail: mychelle@cnen.gov.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Consumption of food is usually the most important route by which natural and artificial radionuclides can enter the human body. An assessment of radionuclide levels in different foods and diets is therefore important to estimate the intake of these radionuclides by man. The contamination by radionuclides can occur via the food chain (soil, root, plant and animal), with emphasis to the long half-life radionuclides, which can also have their transfer through the animal meat. The inclusion of meat in human nutrition is important because it is an excellent source of high quality protein, nutrient related to construction and cell regeneration. This work aims the determination of natural radionuclides ({sup 234}U, {sup 235}U, {sup 238}U, {sup 228}Th, {sup 230}Th, {sup 232}Th, {sup 226}Ra, {sup 228}Ra, and {sup 210}Pb) in meat samples. Five groups of samples were analyzed, such as cattle meat (beef), fish, pork, poultry, and processed meat, after radiochemical separation followed by alpha or alpha beta spectrophotometry, and total count quantification. The determination of these radionuclides is very important because they are products of the natural decay series of {sup 238}U and {sup 232}Th, being easily found in meat samples. (author)

  5. Anthropogenic radionuclides in sea water

    International Nuclear Information System (INIS)

    Honda, Teruyuki

    1999-01-01

    On the basis of data base of IAEA-MEL (International Atomic Energy Agency, Marine Environment Laboratory) and other organizations, the distribution and behavior of anthropogenic radionuclides in sea water, 137 Cs, 90 Sr, 239+240 Pu, 241 Am and 3 H, are explained. 137 Cs (β - , γ: 30.2 y half life) is the most important pollution source and tracer to make clear mixture and diffusion process in seawater. The concentration of 137 Cs in surface seawater of Northern Hemisphere is larger than that of Southern Hemisphere, because many inner space nuclear tests were carried out in the Northern Hemisphere. Especially, the concentration of Northern-east Ocean and Mediterranean Sea are 21 Bq/m 3 and 13 Bq/m 3 , respectively, ten times as much as the other, because of discharge of nuclear fuel reprocessing plants and Chernobyl accident. 2.5 Bq/m 3 137 Cs was observed in North Atlantic Ocean. Behavior of 90 Sr (β - : 29.0 y half life) is the same as 137 Sr in seawater. Secular change of 137 Sr and 90 Sr in seawater in coastal areas of Japan shows decrease of the values from 1964 and reached to 2 to 4 mBq/l and 1 to 3 mBq/l, respectively. 239+240 Pu is the most large load of transuranic elements (TRU) in the earth and originated from nuclear tests. The concentration of 239+240 Pu is 20 to 30 (10 -4 pCi/l, 1968) in the Pacific Ocean and 2.5 to 10.0 μBq/l (1982 to 1993). 241 Am (α: 433 y half life) is generated by decay of 241 Pu. Accordingly, the maximum value is observed after about 100 years. 241 Am/ 239+240 Pu showed less than about 0.3 of fall out, so that emission of 241 Am increases much more than 239+240 Pu. 3 H (β - : 12.3 y half life) has the most short half life in the anthropogenic radionuclides and exists the form as water (HTO) in the sea. The origin of 3 H is hydrogen bomb tests during 1952 and 1975. The concentration of 3 H in sea is average 3.6 TU (1994). The vertical profile of 137 Cs and 90 Sr is similar to each other since both nuclides become ions such

  6. Longtime radionuclide monitoring in the vicinity of Salaspils nuclear reactor

    International Nuclear Information System (INIS)

    Riekstina, D.; Berzins, J.; Krasta, T.; Skrypnik, O.; Alksnis, J.

    2016-01-01

    The research nuclear reactor in Salaspils was decommissioned in 1998. Now reactor is partially dismantled and its territory is used as a temporary storage of radioactivity contaminated materials and water. Environment radioactivity monitoring for presence of artificial radionuclides in the vicinity of Salaspils nuclear reactor is carried out since 1990. Data include Cs-137 concentration in soils, tritium concentration in ground water, as well as H-3, Cs-137, Co-60 concentration and gross beta-activity of reactors sewage and rainwater drainage. The systematic monitoring allowed to detect in December 2014 a leakage from the special wastewater basin and so to prevent a pollution of ground water outside reactors territory.

  7. Intercomparison of radionuclide measurements in marine sediment sample IAEA-368

    International Nuclear Information System (INIS)

    Ballestra, S.; Lopez, J.J.; Gastaud, J.; Parsi, P.; Vas, D.; Noshkin, V.

    1991-08-01

    The results of an intercomparison exercise on a Pacific Ocean sediment sample, IAEA-368, designed for the determination of artificial and natural radionuclides levels, are reported. The data from 89 laboratories representing 37 countries have been evaluated. The following are the recommended values, with confidence intervals, for 60 Co, 155 Eu, 210 7Pb, 226 Ra, 238 U, 238 Pu and 239+240 Pu (Reference date: 1 January 1990). Information values for 40 K, 90 Sr, 137 Cs, 228 Th, 230 Th, 232 Th, 234 U, 235 U and 241 Am are also reported. (author)

  8. National low-level waste management program radionuclide report series, Volume 15: Uranium-238

    International Nuclear Information System (INIS)

    Adams, J.P.

    1995-09-01

    This report, Volume 15 of the National Low-Level Waste Management Program Radionuclide Report Series, discusses the radiological and chemical characteristics of uranium-238 ( 238 U). The purpose of the National Low-Level Waste Management Program Radionuclide Report Series is to provide information to state representatives and developers of low-level radioactive waste disposal facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the waste disposal facility environment. This report also includes discussions about waste types and forms in which 238 U can be found, and 238 U behavior in the environment and in the human body

  9. Subject-3: Study on migration of radionuclides released into terrestrial and aquatic environment after nuclear accident

    International Nuclear Information System (INIS)

    Amano, H.; Matsunaga, T.; Ueno, T.; Nagao, S.; Yanase, N.; Tkachenko, Yu.

    2001-01-01

    Subject-3 has been focused on the migration behavior of long-lived radionuclides in the terrestrial surface environment, especially in connection with their chemical and physical forms. Migration behavior of radionuclides is strongly affected with their chemical and physical forms (for example; Gunten and Benes 1995). One of the two categories in Subject-3 consists of migration from surface soils including aging effects of hot particles, plant uptake from contaminated soils, and resuspension of radionuclides. The other is run off by river system, considering the role of organic materials. (author)

  10. Subject-3: Study on migration of radionuclides released into terrestrial and aquatic environment after nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Amano, H.; Matsunaga, T.; Ueno, T.; Nagao, S.; Yanase, N. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Arkhipov, A.N. [Chernobyl Scientific and Technical Center for International Research (Ukraine); Tkachenko, Yu. [The State Enterprise Regional Monitoring and Domestic Control (RADEC) (Unknown)

    2001-03-01

    Subject-3 has been focused on the migration behavior of long-lived radionuclides in the terrestrial surface environment, especially in connection with their chemical and physical forms. Migration behavior of radionuclides is strongly affected with their chemical and physical forms (for example; Gunten and Benes 1995). One of the two categories in Subject-3 consists of migration from surface soils including aging effects of hot particles, plant uptake from contaminated soils, and resuspension of radionuclides. The other is run off by river system, considering the role of organic materials. (author)

  11. Dosimetry in radionuclide therapy

    International Nuclear Information System (INIS)

    Riccabona, G.

    2001-01-01

    While it is known that therapeutic effects of radionuclides are due to absorbed radiation dose and to radiosensitivity, individual dosimetry in 'Gy' is practiced rarely in clinical Nuclear Medicine but 'doses' are described in 'mCi' or 'MBq', which is only indirectly related to 'Gy' in the target. To estimate 'Gy', the volume of the target, maximum concentration of the radiopharmaceutical in it and residence time should be assessed individually. These parameters can be obtained usually only with difficulty, involving possibly also quantitative SPET or PET, modern imaging techniques (sonography, CT, MRT), substitution of y- or positron emitting radiotracers for β - emitting radiopharmaceuticals as well as whole-body distribution studies. Residence time can be estimated by obtaining data on biological half-life of a comparable tracer and transfer of these data in the physical characteristics of the therapeutic agent. With all these possibilities for gross dosimetry the establishment of a dose-response-relation should be possible. As distribution of the radiopharmaceutical in lesions is frequently inhomogenous and microdosimetric conditions are difficult to assess in vivo as yet, it could be observed since decades that empirically set, sometimes 'fixed' doses (mCi or MBq) can also be successful in many diseases. Detailed dosimetric studies, however, are work- and cost-intensive. Nevertheless, one should be aware at a time when more sophisticated therapeutic possibilities in Nuclear Medicine arise, that we should try to estimate radiation dose (Gy) in our new methods even as differences in individual radiosensitivity cannot be assessed yet and studies to define individual radiosensitivity in lesions should be encouraged. (author)

  12. Performance analysis of numeric solutions applied to biokinetics of radionuclides

    International Nuclear Information System (INIS)

    Mingatos, Danielle dos Santos; Bevilacqua, Joyce da Silva

    2013-01-01

    Biokinetics models for radionuclides applied to dosimetry problems are constantly reviewed by ICRP. The radionuclide trajectory could be represented by compartmental models, assuming constant transfer rates between compartments. A better understanding of physiological or biochemical phenomena, improve the comprehension of radionuclide behavior in the human body and, in general, more complex compartmental models are proposed, increasing the difficulty of obtaining the analytical solution for the system of first order differential equations. Even with constant transfer rates numerical solutions must be carefully implemented because of almost singular characteristic of the matrix of coefficients. In this work we compare numerical methods with different strategies for ICRP-78 models for Thorium-228 and Uranium-234. The impact of uncertainty in the parameters of the equations is also estimated for local and global truncation errors. (author)

  13. Radionuclide Sensors for Water Monitoring

    International Nuclear Information System (INIS)

    Grate, Jay W.; Egorov, Oleg B.; DeVol, Timothy A.

    2004-01-01

    Radionuclide contamination in the soil and groundwater at U.S. Department of Energy (DOE) sites is a severe problem that requires monitoring and remediation. Radionuclide measurement techniques are needed to monitor surface waters, groundwater, and process waters. Typically, water samples are collected and transported to an analytical laboratory, where costly radiochemical analyses are performed. To date, there has been very little development of selective radionuclide sensors for alpha- and beta-emitting radionuclides such as 90Sr, 99Tc, and various actinides of interest. The objective of this project is to investigate novel sensor concepts and materials for sensitive and selective determination of beta- and alpha-emitting radionuclide contaminants in water. To meet the requirements for loW--level, isotope-specific detection, the proposed sensors are based on radiometric detection. As a means to address the fundamental challenge of the short ranges of beta and alpha particle s in water, our overall approach is based on localization of preconcentration/separation chemistries directly on or within the active area of a radioactivity detector. Automated microfluidics is used for sample manipulation and sensor regeneration or renewal. The outcome of these investigations will be the knowledge necessary to choose appropriate chemistries for selective preconcentration of radionuclides from environmental samples, new materials that combine chemical selectivity with scintillating properties, new materials that add chemical selectivity to solid-state diode detectors, new preconcentrating column sensors, and improved instrumentation and signal processing for selective radionuclide sensors. New knowledge will provide the basis for designing effective probes and instrumentation for field and in situ measurements

  14. A model for radionuclide transport in the Cooling Water System

    International Nuclear Information System (INIS)

    Kahook, S.D.

    1992-08-01

    A radionuclide transport model developed to assess radiological levels in the K-reactor Cooling Water System (CWS) in the event of an inadvertent process water (PW) leakage to the cooling water (CW) in the heat exchangers (HX) is described. During and following a process water leak, the radionuclide transport model determines the time-dependent release rates of radionuclide from the cooling water system to the environment via evaporation to the atmosphere and blow-down to the Savannah River. The developed model allows for delay times associated with the transport of the cooling water radioactivity through cooling water system components. Additionally, this model simulates the time-dependent behavior of radionuclides levels in various CWS components. The developed model is incorporated into the K-reactor Cooling Tower Activity (KCTA) code. KCTA allows the accident (heat exchanger leak rate) and the cooling tower blow-down and evaporation rates to be described as time-dependent functions. Thus, the postulated leak and the consequence of the assumed leak can be modelled realistically. This model is the first of three models to be ultimately assembled to form a comprehensive Liquid Pathway Activity System (LPAS). LPAS will offer integrated formation, transport, deposition, and release estimates for radionuclides formed in a SRS facility. Process water and river water modules are forthcoming as input and downstream components, respectively, for KCTA

  15. Radionuclide Distribution in the Soil on the Stabatishkes Site in the Vicinity of the Ignalina NPP

    Directory of Open Access Journals (Sweden)

    Jevgenij Aliončik

    2011-02-01

    Full Text Available A near surface repository for low and intermediate-level short-lived radioactive waste will be built on the Stabatiškės site in the vicinity of Ignalina NPP during decommissioning works. The reservoir can also be used for the waste stored in the temporary repositories of the Ignalina NPP. Engineering and nature protective barriers are used in the repository for radioactive waste, however, radionuclides can spread into the environment, extend in the biosphere and cause (define the external power light exposure of the environment due to the natural and premature (prescheduled degradation of the engineering barriers of the repository. The properties of the soil (acidity, quantity of organic substances, humidity are being investigated for estimating the possible migration and dispersion of radionuclides. The activity of radionuclides in the soil is also estimated before building the repository. Natural and artificial radionuclides make the pollution of the soil, and therefore the accumulation and vertical migration of artificial (137Cs, 60Co and natural (226Ra, 232Th, 40K radionuclides are being researched in the soil on the Stabatiškės site.Article in Lithuanian

  16. Study of the thermo-mechanical behavior of medium carbon microalloyed steel during hot forming process using an artificial neural network; Estudio del comportamiento termo-mecanico de un acero microaleado de medio carbono durante un proceso de conformado en caliente usando una red neuronal artificial

    Energy Technology Data Exchange (ETDEWEB)

    Alcelay, I.; Pena, E.; Al Omar, A.

    2016-10-01

    The thermo-mechanical behavior of medium carbon microalloyed steel has been analyzed by an Artificial Neural Network (ANN). The flow curves for training the ANN have been obtained from the hot compression tests, carried out over a temperature range varying from 900 to 1150 degree centigrade and at different true strain rates ranging from 10{sup -}4 to 10 s{sup -}1. It has been found that the ANN model developed in this study is capable to predict accurately and efficiently the flow behavior of the studied steel and there is a good agreement between the experimental results and the ANN results. To analyze the formability of the studied steel, processing maps have been constructed on the basis of the Dynamic Materials Model (DMM), using the ANN values of the flow stress. The study of maps reveals the different domains of the flow behavior of the studied steel and shows the great similarity between the experimental results and the theoretical results, so the use of the ANN can constitute an interesting alternative for design and study of hot forming processes. (Author)

  17. Artificial Hydration and Nutrition

    Science.gov (United States)

    ... Crisis Situations Pets and Animals myhealthfinder Food and Nutrition Healthy Food Choices Weight Loss and Diet Plans ... Your Health Resources Healthcare Management Artificial Hydration and Nutrition Artificial Hydration and Nutrition Share Print Patients who ...

  18. Artificial Disc Replacement

    Science.gov (United States)

    ... Spondylolisthesis BLOG FIND A SPECIALIST Treatments Artificial Disc Replacement (ADR) Patient Education Committee Jamie Baisden The disc ... Disc An artificial disc (also called a disc replacement, disc prosthesis or spine arthroplasty device) is a ...

  19. Inverse problem in radionuclide transport

    International Nuclear Information System (INIS)

    Yu, C.

    1988-01-01

    The disposal of radioactive waste must comply with the performance objectives set forth in 10 CFR 61 for low-level waste (LLW) and 10 CFR 60 for high-level waste (HLW). To determine probable compliance, the proposed disposal system can be modeled to predict its performance. One of the difficulties encountered in such a study is modeling the migration of radionuclides through a complex geologic medium for the long term. Although many radionuclide transport models exist in the literature, the accuracy of the model prediction is highly dependent on the model parameters used. The problem of using known parameters in a radionuclide transport model to predict radionuclide concentrations is a direct problem (DP); whereas the reverse of DP, i.e., the parameter identification problem of determining model parameters from known radionuclide concentrations, is called the inverse problem (IP). In this study, a procedure to solve IP is tested, using the regression technique. Several nonlinear regression programs are examined, and the best one is recommended. 13 refs., 1 tab

  20. Radionuclide Retention in Concrete Wasteforms

    Energy Technology Data Exchange (ETDEWEB)

    Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

    2012-09-24

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  1. Radionuclide injury to the lung

    International Nuclear Information System (INIS)

    Dagle, G.E.; Sanders, C.L.

    1984-01-01

    Radionuclide injury to the lung has been studied in rats, hamsters, dogs, mice and baboons. Exposure of the lung to high dose levels of radionuclides produces a spectrum of progressively more severe functional and morphological changes, ranging from radiation pneumonitis and fibrosis to lung tumors. These changes are somewhat similar for different species. Their severity can be related to the absorbed radiation dose (measured in rads) produced by alpha, beta or gamma radiation emanating from various deposited radionuclides. The chemicophysical forms of radionuclides and spatial-temporal factors are also important variables. As with other forms of injury to the lung, repair attempts are highlighted by fibrosis and proliferation of pulmonary epithelium. Lung tumors are the principal late effect observed in experimental animals following pulmonary deposition of radionuclides at dose levels that do not result in early deaths from radiation pneumonitis or fibrosis. The predominant lung tumors described have been of epithelial origin and have been classified, in decreasing frequency of occurrence, as adenocarcinoma, bronchioloalveolar carcinoma, epidermoid carcinomas and combined epidermoid and adenocarcinoma. Mesothelioma and fibrosarcoma have been observed in rats, but less commonly in other species. Hemangiosarcomas were frequently observed in dogs exposed to beta-gamma emitters, and occasionally in rats exposed to alpha emitters. These morphologic changes in the lungs of experimental animals were reviewed and issues relevant to the prediction of human hazards discussed. 88 references

  2. Artificial life and Piaget.

    Science.gov (United States)

    Mueller, Ulrich; Grobman, K H.

    2003-04-01

    Artificial life provides important theoretical and methodological tools for the investigation of Piaget's developmental theory. This new method uses artificial neural networks to simulate living phenomena in a computer. A recent study by Parisi and Schlesinger suggests that artificial life might reinvigorate the Piagetian framework. We contrast artificial life with traditional cognitivist approaches, discuss the role of innateness in development, and examine the relation between physiological and psychological explanations of intelligent behaviour.

  3. Development of AI (Artificial Intelligence)-based simulation system for man-machine system behavior in accidental situations of nuclear power plant

    International Nuclear Information System (INIS)

    Yoshida, Kazuo; Yokobayashi, Masao; Tanabe, Fumiya; Kawase, Katumi.

    1996-01-01

    A prototype version of a computer simulation system named JACOS (JAeri COgnitive Simulation system) has been developed at JAERI (Japan Atomic Energy Research Institute) to simulate the man-machine system behavior in which both the cognitive behavior of a human operator and the plant behavior affect each other. The objectives of this system development is to provide man-machine system analysts with detailed information on the cognitive process of an operator and the plant behavior affected by operator's actions in accidental situations of an NPP (nuclear power plant). The simulation system consists of an operator model and a plant model which are coupled dynamically. The operator model simulates an operator's cognitive behavior in accidental situations based on the decision ladder model of Rasmussen, and is implemented using the AI-techniques of the distributed cooperative inference method with the so-called blackboard architecture. Rule-based behavior is simulated using knowledge representation with If-Then type of rules. Knowledge-based behavior is simulated using knowledge representation with MFM (Multilevel Flow Modeling) and qualitative reasoning method. Cognitive characteristics of attentional narrowing, limitation of short-term memory, and knowledge recalling from long-term memory are also modeled. The plant model of a 3-loop PWR is also developed using a best estimate thermal-hydraulic analysis code RELAP5/MOD2. Some simulations of incidents were performed to verify the human model. It was found that AI-techniques used in the human model are suitable to simulate the operator's cognitive behavior in an NPP accident. The models of cognitive characteristics were investigated in the effects on simulated results of cognitive behaviors. (author)

  4. Method of preparing radionuclide doses

    International Nuclear Information System (INIS)

    Kuperus, J.H.

    1987-01-01

    A method is described of preparing aliquot dosea of a tracer material useful in diagnostic nuclear medicine comprising: storing discrete quantities of a lyophilized radionuclide carrier in separate tubular containers from which air and moisture is excluded, selecting from the tubular containers a container in which is stored a carrier appropriate for a nuclear diagnostic test to be performed, interposing the selected container between the needle and the barrel of a hypodermic syringe, and drawing a predetermined amount of a liquid containing a radionuclide tracer in known concentration into the hypodermic syringe barrel through the hypodermic needle and through the selected container to dissolve the discrete quantity of lyophilized carrier therein to combine the carrier with the radionuclide tracer to form an aliquot dose of nuclear diagnostic tracer material, as needed

  5. Methods of separating short half-life radionuclides from a mixture of radionuclides

    International Nuclear Information System (INIS)

    Bray, L.A.; Ryan, J.L.

    1998-01-01

    The present invention is a method of obtaining a radionuclide product selected from the group consisting of 223 Ra and 225 Ac, from a radionuclide ''cow'' of 227 Ac or 229 Th respectively. The method comprises the steps of (a) permitting ingrowth of at least one radionuclide daughter from said radionuclide ''cow'' forming an ingrown mixture; (b) insuring that the ingrown mixture is a nitric acid ingrown mixture; (c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the ''cow'' from at least one radionuclide daughter; (d) insuring that the at least one radionuclide daughter contains the radionuclide product; (e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and (f) recycling the at least one radionuclide daughter by adding it to the ''cow''. In one embodiment the radionuclide ''cow'' is the 227 Ac, the at least one daughter radionuclide is a 227 Th and the product radionuclide is the 223 Ra and the first nitrate form ion exchange column passes the 227 Ac and retains the 227 Th. In another embodiment the radionuclide ''cow'' is the 229 Th, the at least one daughter radionuclide is a 225 Ra and said product radionuclide is the 225 Ac and the 225 Ac and nitrate form ion exchange column retains the 229 Th and passes the 225 Ra/Ac. 8 figs

  6. Report on the intercomparison run IAEA-307 radionuclides in sea plant

    International Nuclear Information System (INIS)

    Veglia, A.; Ballestra, S.; Vas, D.

    1989-10-01

    The results of an intercomparison exercise on a Mediterranean Sea plant sample, coded as IAEA-307, designed for the determination of artificial and natural radionuclide levels, are reported. This sample was collected along the shore from the vicinity of the Principality of Monaco in October 1986. The data from 66 laboratories representing 31 countries have been evaluated. The most frequently measured radionuclides: 106 Ru, 110m Ag, 134 Cs, 137 Cs, 238 Pu, 239+240 Pu, 241 Am, 40 K and 226 Ra. 10 refs, 38 tabs

  7. Report on the intercomparison run IAEA-352 radionuclides in tuna fish flesh

    International Nuclear Information System (INIS)

    Ballestra, S.; Vas, D.; Lopez, J.J.; Noshkin, V.

    1990-08-01

    The results of an intercomparison exercise on a sample of tuna fish flesh from the Mediterranean Sea, IAEA-352, designed for the determination of artificial and natural radionuclides levels, are reported. The data from 63 laboratories from 31 countries have been evaluated. The following are the recommended values, with confidence intervals, for the most frequently measured radionuclides (Reference data: 1 January 1989): 137 Cs 2.7 Bq kg -1 , 90 Sr 0.2 Bq Kg -1 , 40 K 391 Bq Kg -1 , 210 Pb 0.6 Bq Kg -1 , 210 Po 2.2 Bq Kg -1 . Tabs

  8. Producing new radionuclides for medicine

    International Nuclear Information System (INIS)

    Michaut, C.

    2009-01-01

    The Arronax cyclotron, a new particle accelerator dedicated to the production of radionuclides for medicine and research has been commissioned in Nantes (France). Because of its unique features: an energy of 70 MeV and an intensity of 750 μA, Arronax will produce radionuclides that can not be produce in present cyclotrons. Among others it will produce Strontium-82 and Germanium-68 that are the precursors for Rubidium-82 and Gallium-68 respectively. 20 per cent of the research works will be dedicated to other domains like radioactive wastes, the radiation biological damage and the radiation damage on electronic devices. (A.C.)

  9. Radionuclide migration in geological formations

    International Nuclear Information System (INIS)

    Barbreau, A.; Heremans, R.; Skytte Jensen, B.

    1980-01-01

    Radioactive waste disposal into geological formation is based on the capacity of rocks to confine radioactivity for a long period of time. Radionuclide migration from the repository to the environment depends on different mechanisms and phenomena whose two main ones are groundwater flow and the retention and ion-exchange property of rocks. Many studies are underway presently in EEC countries concerning hydrodynamic characteristics of deep geological formations as well as in radionuclide retention capacity and modelling. Important results have already been achieved which show the complexity of some phenomena and further studies shall principally be developed taking into account real conditions of the repository and its environment

  10. Automatic alignment of radionuclide images

    International Nuclear Information System (INIS)

    Barber, D.C.

    1982-01-01

    The variability of the position, dimensions and orientation of a radionuclide image within the field of view of a gamma camera hampers attempts to analyse the image numerically. This paper describes a method of using a set of training images of a particular type, in this case right lateral brain images, to define the likely variations in the position, dimensions and orientation for that type of image and to provide alignment data for a program that automatically aligns new images of the specified type to a standard position, size and orientation. Examples are given of the use of this method on three types of radionuclide image. (author)

  11. Radionuclide techniques for brain imaging

    International Nuclear Information System (INIS)

    Cowan, R.J.; Moody, D.M.

    1984-01-01

    Over the past decade, many of the prime indications for radionuclide brain scanning have become instead indications for CCT, and nuclear medicine studies of the brain have assumed more of a complementary, supportive role. However, there is great promise for improvement in central nervous system radionuclide applications with advances anticipated in both radiopharmaceuticals and instrumentation. Nuclear medicine is continuing to function as a powerful research tool and, in the relatively near future, may regain its role as a major clinical test of the central nervous system

  12. MATADOR (Methods for the Analysis of Transport And Deposition Of Radionuclides) code description and User's Manual

    International Nuclear Information System (INIS)

    Avci, H.I.; Raghuram, S.; Baybutt, P.

    1985-04-01

    A new computer code called MATADOR (Methods for the Analysis of Transport And Deposition Of Radionuclides) has been developed to replace the CORRAL-2 computer code which was written for the Reactor Safety Study (WASH-1400). This report is a User's Manual for MATADOR. MATADOR is intended for use in system risk studies to analyze radionuclide transport and deposition in reactor containments. The principal output of the code is information on the timing and magnitude of radionuclide releases to the environment as a result of severely degraded core accidents. MATADOR considers the transport of radionuclides through the containment and their removal by natural deposition and by engineered safety systems such as sprays. It is capable of analyzing the behavior of radionuclides existing either as vapors or aerosols in the containment. The code requires input data on the source terms into the containment, the geometry of the containment, and thermal-hydraulic conditions in the containment

  13. Improving cancer treatment with cyclotron produced radionuclides

    International Nuclear Information System (INIS)

    Larson, S.M.; Finn, R.D.

    1992-01-01

    Our goal is to improve the scientific basis for tumor diagnosis, treatment and treatment follow-up based on the use of cyclotron produced radiotracers in oncology. The grant includes 3 interactive components: Radiochemistry/Cyclotron; Pharmacology; and Immunology. The radiochemistry group seeks to develop innovative cyclotron targetry, radiopharmaceuticals, and radiolabeled antibodies, which are then used to assess important unanswered questions in tumor pharmacology and immunology. Examples include selected positron emitting radionuclides, such as Iodine-124, and Ga-66; I-124, I-123, I-131 labeled iododeoxyuridine, C-11 colchicine, and antimetabolites, like C-11 methotrexate; and radiolabeled antibodies, 3F8, M195, A33, and MRK16 for application in the pharmacology and immunology projects. The pharmacology program studies tumor resistance to chemotherapy, particularly the phenomenon of multidrug resistance and the relationship between tumor uptake and retention and the tumor response for anti-metabolite drugs. The immunology program studies the physiology of antibody localization at the tissue level as the basis for novel approaches to improving tumor localization such as through the use of an artificial lymphatic system which mechanically reduces intratumoral pressures in tumors in vivo. Quantitative imaging approaches based on PET and SPECT in radioimmunotherapy are studied to give greater insight into the physiology of tumor localization and dosimetry

  14. Dynamic Effects of Tank Waste Aging on Radionuclide-Complexant Interactions - Final Report - 10/01/1997 - 10/01/2000

    Energy Technology Data Exchange (ETDEWEB)

    Chamberlin, Rebecca M.; Arterburn, Jeffrey B. rmchamberlin@lanl.gov; jarterbu@nmsu.edu

    2000-10-01

    The long-range objective of this project is to provide a scientific basis for safely processing high-level nuclear tanks wastes for disposal. Our goals are to identify a means to prepare realistic simulant formulations for complexant-containing Hanford tank wastes, and then use those simulants to determine the relative importance of various organic complexants and their breakdown products on the partitioning of important radionuclides. The harsh chemical and radiolytic environment in high-level waste tanks alters both the organic complexants and the metal species, producing radionuclide-chelator complexes that resist standard separation methods. A detailed understanding of the complexation reactions of the key radionuclides in tank wastes would allow for reliable, science-based solutions for high-level waste processing, but a key problem is that tank waste samples are exceedingly difficult to obtain, transport and handle in the laboratory. In contrast, freshly-prepared simulated wastes are safe and readily obtained, but they do not reproduce the partitioning behavior of actual tank waste samples. For this project, we will first artificially age complexant-containing tank waste simulants using microwave, ultrasound, and photolysis techniques that can be applied in any standard laboratory. The aged samples will be compared to samples of actual Hanford tank wastes to determine the most realistic aging method, on the basis of the organic fragments present, and the oxidation states and partitioning behavior of important radionuclides such as 90Sr, 99Tc, and 239Pu. Our successful completion of this goal will make it possible for scientists in academic and industrial laboratories to address tank waste remediation problems without the enormous costs and hazards associated with handling actual tank waste samples. Later, we will use our simulant aging process to investigate the relative effects of chelator degradation products on the partitioning of important radionuclides

  15. Dynamic Effects of Tank Waste Aging on Radionuclide-Complexant Interactions - Final Report - 10/01/1997 - 10/01/2000

    International Nuclear Information System (INIS)

    Chamberlin, Rebecca M.; Arterburn, Jeffrey B.

    2000-01-01

    The long-range objective of this project is to provide a scientific basis for safely processing high-level nuclear tanks wastes for disposal. Our goals are to identify a means to prepare realistic simulant formulations for complexant-containing Hanford tank wastes, and then use those simulants to determine the relative importance of various organic complexants and their breakdown products on the partitioning of important radionuclides. The harsh chemical and radiolytic environment in high-level waste tanks alters both the organic complexants and the metal species, producing radionuclide-chelator complexes that resist standard separation methods. A detailed understanding of the complexation reactions of the key radionuclides in tank wastes would allow for reliable, science-based solutions for high-level waste processing, but a key problem is that tank waste samples are exceedingly difficult to obtain, transport and handle in the laboratory. In contrast, freshly-prepared simulated wastes are safe and readily obtained, but they do not reproduce the partitioning behavior of actual tank waste samples. For this project, we will first artificially age complexant-containing tank waste simulants using microwave, ultrasound, and photolysis techniques that can be applied in any standard laboratory. The aged samples will be compared to samples of actual Hanford tank wastes to determine the most realistic aging method, on the basis of the organic fragments present, and the oxidation states and partitioning behavior of important radionuclides such as 90Sr, 99Tc, and 239Pu. Our successful completion of this goal will make it possible for scientists in academic and industrial laboratories to address tank waste remediation problems without the enormous costs and hazards associated with handling actual tank waste samples. Later, we will use our simulant aging process to investigate the relative effects of chelator degradation products on the partitioning of important radionuclides

  16. Daily intakes of radionuclides in Japanese standard diets

    International Nuclear Information System (INIS)

    Terada, H.; Sugiyama, H.; Iijima, I.; Isomura, K.; Kobayashi, J.

    2005-01-01

    Daily intakes of radionuclides in Japanese standard diets were investigated. Food samples were collected from 9 cities of Japan using the market basket method according to the reports of National Nutrition Study in Japan (2000). These samples were categorized the following 14 groups; Group l: rice, rice products; Group 2: grain, seeds, potato; Group 3: sugar, confectionery; Group 4: oils and fats; Group 5: beans; Group 6: fruits; Group 7: green and yellow vegetables; Group 8: other vegetables; mushrooms, seaweed; Group 9: seasoning, drinks; Group 10: fish and shellfish; Group 11: meat, eggs; Group 12: milk, milk products; Group 13: other foods; and Group 14 was drinking water. Each group was homogenized separately after cooking the food materials. Determination of radioactivity was performed by gamma ray spectrometry. The only artificial radionuclide detected from gamma ray spectrometry was 137 CS, and its concentrations of each sample were almost less than 0.1 Bq/kg. Strontium-90 and 238 U concentrations of the total diet samples were analyzed with chemical separation. The concentrations of 90 Sr and 238 U were in the range of 0.013-0.031 Bq/kg, 0.0039-0.014 Bq/kg respectively, and a large difference was not found among the concentrations of each nuclide in 9 cities. We would like to estimate internal radiation dose to Japanese population from the dietary intakes of these radionuclides.

  17. Real-time radionuclide identification in γ-emitter mixtures based on spiking neural network

    International Nuclear Information System (INIS)

    Bobin, C.; Bichler, O.; Lourenço, V.; Thiam, C.; Thévenin, M.

    2016-01-01

    Portal radiation monitors dedicated to the prevention of illegal traffic of nuclear materials at international borders need to deliver as fast as possible a radionuclide identification of a potential radiological threat. Spectrometry techniques applied to identify the radionuclides contributing to γ-emitter mixtures are usually performed using off-line spectrum analysis. As an alternative to these usual methods, a real-time processing based on an artificial neural network and Bayes’ rule is proposed for fast radionuclide identification. The validation of this real-time approach was carried out using γ-emitter spectra ( 241 Am, 133 Ba, 207 Bi, 60 Co, 137 Cs) obtained with a high-efficiency well-type NaI(Tl). The first tests showed that the proposed algorithm enables a fast identification of each γ-emitting radionuclide using the information given by the whole spectrum. Based on an iterative process, the on-line analysis only needs low-statistics spectra without energy calibration to identify the nature of a radiological threat. - Highlights: • A fast radionuclide identification algorithm applicable in spectroscopic portal monitors is presented. • The proposed algorithm combines a Bayesian sequential approach and a spiking neural network. • The algorithm was validated using the mixture of γ-emitter spectra provided by a well-type NaI(Tl) detector. • The radionuclide identification process is implemented using the whole γ-spectrum without energy calibration.

  18. The uptake of radionuclides from inadvertent consumption of soil by grazing animals

    International Nuclear Information System (INIS)

    Green, N.; Dodd, N.J.

    1988-01-01

    Investigations of the transfer to man of artificially-produced radionuclides through food chains have shown that the inadvertent consumption of soil by grazing animals can give variations in estimates of transfer coefficients, especially for radionuclides that are poorly absorbed by plant roots. Even small masses of soil adhering to herbage or directly ingested can make a significant contribution to the intake inventory in terms of activity. Although the activity concentrations of soil-contaminated herbage are elevated, the radionuclides associated with the soil may not necessarily be in a form which is easily absorbed by the animal. Attempts must be made, therefore, to quantify soil intake and the subsequent radionuclide uptake by this mechanism. A field investigation of the uptake of radionuclides by farm animals grazing near the Sellafield nuclear reprocessing plant has been pursued. The aims of the study were to estimate the transfer to muscle and other tissues. This paper describes the methods used to estimate both the soil intake and the consequent availability of radionuclides associated with the soil. The measurements were used to evaluate the contribution to tissue content of inadvertent consumption of soil by cows and sheep. 10 refs.; 2 tabs

  19. Determination of alpha radionuclides in fish

    International Nuclear Information System (INIS)

    Pernicka, L.; Matel, L.; Rosskopfova, O.

    2001-01-01

    In atmospheric water, external water and undercurrent the occurrence of radionuclides is usual. It is an important factor of quality of the environment. Plants ingest radionuclides from water and with they everyone. And it arises radioactivity infest food-chain. Radiotoxicity of this radionuclides is very deer sometimes. The sensitive radiochemical procedures for their determination are necessarily important. The poster presents the combined procedure used at our laboratory for determination of alpha radionuclides in biological samples. (authors)

  20. Naturally occurring radionuclides in food

    International Nuclear Information System (INIS)

    Djujic, I.

    1995-01-01

    The naturally occurring radionuclides are the major source of radiation exposure to humans. The principal way of natural radiation exposure is the inhalation of 222 Rn decay products (about 85% of the total). The remainder is equally divided between internally deposited radionuclides, cosmic and terrestrial sources. In the present study, the content of 40 K, 210 Pb, 226 Ra, 230 Th, 232 Th and 238 U in representative food samples (milk, pork, beef, potatoes, wheat and corn flour) and samples of different food items that do not represent entire national production but provide interesting additional data for approximative calculation of naturally occurring radionuclide intake is presented. Daily weight of food eaten, participation of food groups, as well as daily intake by food of mentioned naturally occurring radionuclides in the Serbian diet was obtained on the base of house hold budget surveys. The result obtained for daily intake estimates in mBq for Serbian population are 78.1 ( 40 K), 38.2( 210 Pb), 52.3( 226 Ra), 2.0( 230 Th) and 12.5( 238 U). (author)