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Sample records for radioactivity artificially induced

  1. Artificial radioactivity in Lough Foyle

    The purpose of this study was to assess the extent to which the marine environment of Lough Foyle, situated on the north coast of Ireland, has been affected by artificial radioactivity released from Sellafield. Although traces of plutonium, americium and radiocaesium from Sellafield are detectable in Lough Foyle, the concentrations in various marine media are significantly lower than those found along the NE coast of Ireland and in the western Irish Sea. The minute quantities of artificial radioactivity found in Lough Foyle are of negligible radiological significance

  2. Artificial radioactivity and its application

    The year 2000-2001 is the birth centenary year of Prof. Frederic Joliot Curie, who along with Irene Joliot Curie discovered artificial radioactivity in 1934. This opened up new challenges in the field of radiochemistry. In this paper, a brief discussion on historical background of radioactivity is given. This is followed by the methods of production of radioisotopes, general principles of using radiotracers. Some representative applications in various fields are discussed with the methodology and results. (author)

  3. Artificial radioactivity in the sea. Chapter 22

    The subject is covered in sections, entitled: global inventory of artificially produced radionuclides (including fallout and controlled disposal of radioactive wastes from nuclear power production); radioactivity as a potential pollutant (including public health implications of discharges from selected sites); radiation dose commitment to marine organisms; spectrum of artificially-produced radionuclides in marine environments and their overall distribution; distribution of radionuclides in seawater; distribution of radionuclides in sediment; bioaccumulation. (U.K.)

  4. Artificial radioactivity in Carlingford Lough

    The principal objective of this study was to assess whether radioactivity concentrations in a wide range of environmental materials from the Lough were enhanced above general levels found elsewhere along the east and north-east coasts of Ireland. Other objectives included an examination of gamma dose rates in air over inter-tidal sediments throughout the Lough and an examination of coastal soils to determine the extent of sea-to-land transfer of plutonium and , by inference, americium

  5. Artificial radioactivity of the Black Sea

    The artificial (technogenic) radioactivity of the Black Sea was studied before and after the Chernobyl event, both during the period of nuclear tests and the moratorium on such tests. Part I describes the forms of artificial radionuclides in seawater. Part II discusses the input into the Black Sea resulting from global fallouts. Part III is devoted to the Chernobyl radioecological consequences. The accumulation of radionuclides in bottom sediments and hydrobionts is considered in Part IV, while Part V is devoted to the modelling of the processes of radionuclide transport in Black Sea waters. 29 tabs., 52 figs., 135 refs

  6. On the discovery of artificial radioactivity

    A review is presented of the elegant Joliot-Curie physical experiments which showed for the first time the possibility of producing artificial radioactive nuclei. An attempt has been made to explain the results of their equally elegant chemical experiments that unequivocally demonstrated the chemical change of elements by nuclear processes. These experiments are discussed in the light of present-day radiochemistry, keeping in mind the scientific and historical context in which they were originally performed. (orig.)

  7. Artificial neutralization of radioactivity-I

    In this paper we have worked out effects of spherical pressure on conversion transition probabilities in light atoms i.e. Z=1,2,3.... For this purpose we have considered only a few conversion transitions i.e. EO, El, Ml both in free and spherically compressed muonic atoms. Our calculations have shown that conversion transition probabilities under compression increase (while Radiation transition probabilities decrease: to be published in-II). These effects led us to present the pioneering concept of an artificial neutralization of radioactivity. Actually in this process gamma-Ray mode of nuclear de-excitation is pressed into beta-mode of nuclear de-excitation. To deal with the problem we have used relativistic Quantum theory i.e. for lepton current and charge densities we have used Dirac's wave functions. (author)

  8. Natural and artificial radioactivity in Great Bratislava

    The results of the aviation measurement of the gamma-radiation are presented in the form of the maps of iso-lines of the concentration of the natural radioactive elements (potassium, uranium, thorium) and artificial radionuclides (cesium-137, cesium-134). From the obtained dates the maps of dose rate of the gamma-radiation in the air are calculated, of the dose equivalent rate and the map of the fraction of the dose equivalent rate from the natural elements potassium, uranium, thorium. The natural radioactivity of the minerals in the Great Bratislava region, especially for the extreme low values of the contain of the thorium, does not amount the average values of the radioactivity of the Earth crust. The area activity of cesium-137 are in the range 2 - 10 kBq.m-2 and cesium-134 is 1 - 2.5 kBq.m-2. From the point of view of the summary level of the external irradiation from the Earth surface the measured zone as relative even is evaluated, in the range 10-100 nSv.h-1. The total average level of the dose rate of the external irradiation of man (inclusively from the cosmic radiation 40-50 nSv.h-1) in the conditions of Bratislava is 100 nSv.h-1. The contribution of external component of the irradiation is 40-100 nSv.h-1 (0.1-0.3 mSv.y-1). The dose equivalent commitment of internal component from the cesium-137 is for the all age category of the population under the level negligible risk 0.01 mSv.y-1

  9. Principle of natural and artificial radioactive series equivalency

    In the present paper one approach used under development of radioactive waste management conception is under consideration. This approach is based on the principle of natural and artificial radioactive series radiotoxic equivalency. The radioactivity of natural and artificial radioactive series has been calculated for 109 - years period. The toxicity evaluation for natural and artificial series has also been made. The correlation between natural radioactive series and their predecessors - actinides produced in thermal and fast reactors - has been considered. It has been shown that systematized reactor series data had great scientific significance and the principle of differential calculation of radiotoxicity was necessary to realize long-lived radioactive waste and uranium and thorium ore radiotoxicity equivalency conception. The calculations show that the execution of equivalency principle is possible for uranium series (4n+2, 4n+1). It is a problem for thorium. series. This principle is impracticable for neptunium series. (author)

  10. Monitoring artificial radioactivity in the Nordic countries

    This report describes the national systems for monitoring artificial radioactivity in the five Nordic countries (Denmark, Finland, Iceland, Norway and Sweden), including national similarities and differences regarding strategy and equipment. The backbone of the national system for early warning is a network of automatic gamma monitoring stations. It is complemented by manual stations and/or survey teams measuring in predetermined points. Air filter stations are used for nuclide specific analyses of aerosols and gaseous iodine. Fallout maps (especially for cesium-137) and isocurves (dose equivalent rates) are produced based on data from airborne measurements, monitoring stations, survey teams and environmental samples. All five countries have extensive programs for checking food contamination. Whole body counting and organ measurements are used to determine internal contamination. External contamination of people, vehicles, goods etc. is checked with survey meters and other equipment at checkpoints or as needed. Field measurements of various kinds complete the national systems. Current routines and systems for exchange of radiation data between the Nordic countries are summarized. A joint Nordic program for airborne measurements is suggested. Possible future development and planned improvements are discussed. (au)

  11. Influence of natural radioactive aerosols on artificial radioactivity detection in the Spanish surveillance networks

    The device used for continuous measurements of artificial ? and ? activity in Spanish radiological surveillance networks is the LB BAI 9850 monitor from the Berthold Company. The temporal variation of radon decay product equilibrium introduces a varying background signal in the artificial radioactivity in these monitors. This unwanted background signal can be significantly reduced by analyzing natural radioactive aerosols and their influence on the monitor

  12. Natural and Artificial Radioactivity in Drinkingwater in Malaga, Spain

    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)

  13. Natural and Artificial Radioactivity in Drinking Water in Malaga, Spain

    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.

  14. Natural and artificial radioactivity in coastal regions of UK

    The transport and bioaccumulation of natural and artificial radionuclides in the coastal regions of UK have been investigated. The magnitude of radionuclide concentration variation throughout the UK coastline has been quantified and where appropriate source terms have been identified. Sites bordering the Irish Sea show the highest levels of artificial radioactivity which are derived from past Sellafield discharges. Enhanced concentrations of natural radioactivity were found in all Whitehaven samples, in sediment at Blackhall Colliery near Hartlepool and in mussels at Aberdeen. Highest radionuclide concentrations were present in Whitehaven mussels - 3124Bqkg-1 dry weight of 210Po. Excluding sites bordering the Irish Sea, levels of natural radionuclides (210Pb, 210Po, 232Th, 238U) were greatly in excess of the artificial radionuclide concentrations in all sample types. The biological preference for accumulation of 210Po relative to its grandparent 210Pb is evident. 210Po/210Pb activity ratios range between 2 and 40 in mussels, winkles and seaweed but only between 0.24 and 1.3 in sediments and sea water. Radiologically, the highest radiation exposure to the public evident from the results would be from the ingestion of Whitehaven mussels (3.2mSv y-1), the greatest single contribution being from technologically enhanced 210Po. (Author)

  15. Modelling of artificial radioactivity migration in environment: a survey

    The aim of this report is to present a compilation and description of models to assess the environmental behaviour and effects of accidental and routine releases of artificial radioactivity from nuclear power facilities. About 60 models are described and a card is given for each one, to indicate in summarized form its features and data content. This collection is intended to help in developing specific personal models by assembling different parts chosen among the most suitable ones of different models of various degrees of sophistication

  16. Natural and artificial radioactivity levels in sediments in Algiers bay

    Natural (238U and 232Th series, 40K) and artificial (137Cs) radioactivity levels in the sediments of Algiers bay were measured using gamma-ray spectrometry. Concentrations (Bq kg-1, dry weight) have been observed to range from 10.8 to 25.0 for 238U, from 6.5 to 31.7 for 232Th, from 55.9 to 607.4 for 40K and from 0.95 to 9.5 for 137Cs. These values are discussed in terms of the facies type of the sea bottom. (Author)

  17. Medical imaging was boosted by the discovery of artificial radioactivity

    This article draws the history of medical imaging since the discovery of artificial radioactivity in 1934. The author reviews the PET (positron emission tomography) and MRI (magnetic resonance imaging) technologies and presents the recent progress in neuro-sciences that have been made possible by using these 2 technologies. Brain imaging has allowed to show: - the impact of emotions on logical mental processes and on mental performances, - the management of memory in the brain of talented quick reckoners, - the degeneration of neurons, and - the link between autism and the presence of structural and functional anomalies in the brain. (A.C.)

  18. Natural and artificial radioactivity in the Svalbard glaciers

    Natural and artificial radioactivity in the snow of 10 Svalbard glaciers has been measured from 31 ice core samples, drilled between 1981 and 1993. Of these ice cores, seven exhibit the well-known level arising from the fallout of the 1961-62 atmospheric thermonuclear tests. The second level, due to the Chernobyl accident (26 April 1986), has been detected in all the studied glaciers; the maximum 137Cs fallout reaches 22 Bq kg-1 and shows a high variability. The natural radioactivity, mostly due to 210Pb, shows an in-depth variation which is not governed by its half-life (22.2 years). These measurements serve many glaciological purposes: absolute dating of the snow layers; air-snow transfer and fallout studies; the determination of mean annual mass balances in the accumulation area of glaciers and their associated spatio-temporal variations. (author)

  19. Natural and artificial radioactivity levels in Livingston Island (Antarctic regions)

    Radioactive contamination of the sea and land is due, on the one hand, to fallout from atmospheric atomic explosions since 1945, and, on the other, to emissions produced by nuclear and radioactive facilities. Given its geographic position far distant from the aforementioned main sources of radioactive contamination, Antarctica should have the lowest levels that can be measured on the Earth of artificial radionuclides in the various receptor media which are characteristic of the trophic chain. In the case of Antarctica, these are melt-water, sea-water, mosses, algae, and lichens. With the aim of contributing basic information on the radiation levels present in the Antarctic ecosystem, we have identified and measured for the first time the radioactive levels of natural emitters (of cosmic and terrestrial origin) and man-made emitters in the aforementioned receptor media, in the vicinity of the Spanish Antarctic Base, Juan Carlos I, situated on Livingston Island in the South Shetland archipelago, Antarctic region. 22 refs., 1 fig., 3 tabs

  20. Artificial radioactivity in the environmental samples as IAEA reference materials

    Radioactivity levels of 110mAg, 241Am, 60Co, 134Cs, 137Cs, 106Ru, 125Sb in some biological and environmental materials have been determined by gamma-ray spectrometry in the frame of 15 intercomparison runs organized by IAEA during 1986-1995. The investigated materials were polluted by various nuclear activities, as follows: 1. Nuclear experiments: IAEA-367, sediment collected in 1982 at the Enewetak Atoll (Marshall Islands in the Pacific Ocean). This atoll was used by the USA during 1948-1958 to test nuclear devices; IAEA-368, sediment collected in June 1989 from the Pacific Ocean at the Mururoa Atoll. Since 1966 this atoll has been used by France to test different nuclear devices. 2. Nuclear installations: IAEA-134, cockle flesh of Cardium edule collected in March 1991 from the Irish Sea (Morecambe Bay), England, about 45 km S-E of Sellafield radioactive discharge; IAEA-135, sediment collected in July 1991 in Lune Estuary-England. This area is influenced by the radioactive discharges of the nuclear installations of Sellafield; IAEA-326, soil collected in 1990 in the region of Kursk Atomic Power Plant (Russia). 3. Nuclear accidents (Chernobyl): IAEA-306, sediment collected in the Baltic Sea during October-November 1986; IAEA-307, seaplant Posidonia oceanica, collected in October 1986 in Mediterranean Sea along the shore, in the vicinity of the Principality of Monaco; IAEA-308, mixed seaweeds collected in October 1986 in Mediterranean Sea along the shore, in the vicinity of the Principality of Monaco; IAEA-156, clover collected during the summer harvest 1986 in Austria; IAEA-321, milk powder collected in autumn 1987 from a processing plant in Europe; IAEA-352, tuna fish flesh collected in April 1988 in the Western Mediterranean Sea; IAEA-373, grass collected from Kiev region during the summer harvest 1990; IAEA-375, soil collected in July 1990 from Brjansk region, Russia; IAEA-300, sediment collected in July 1992 in Bothnian Sea (Baltic Sea). 4. Uncontaminated by nuclear activities: IAEA-327, Podsolic soil collected in 1990 from the Moscow region and considered uncontaminated by radionuclides of the Chernobyl accident or by other nuclear activities. The results obtained by our laboratory are in good agreement with the certified IAEA data. Generally, the concentration of the artificial radionuclides in the investigated samples is higher than that expected from the influence of global fallout in the intercomparison materials distributed before Chernobyl accident. Concerning the nature of these investigated IAEA reference materials, very high values for the concentration levels of cesium radionuclides especially in IAEA-373 (grass) and IAEA-375 (soil) samples collected in the vicinity of Chernobyl Power Station after the nuclear accident in 1986 were found. High levels of radioactivities for the artificial radionuclides were also determined in the samples collected in the neighbourhood of the nuclear installations, especially in marine sediment (IAEA-135). It is of interest to point out the high concentration of cesium radionuclides in IAEA-300 sediment collected in 1992 in the Baltic Sea in comparison with the IAEA-306 sediment collected also in the Baltic Sea in 1986. It seems to be an increase of the Baltic Sea artificial radioactivity by accumulation in time. Marine sediment constitutes an important component of marine ecosystem since it represents the final sink for any releases of wastes into the sea. These certified radioactive materials are very useful to all laboratories engaged in the radioactive pollution investigations on environmental samples. (authors)

  1. Natural and artificial radioactivity determination of some medicinal plants

    Several medicinal plants used in Italy were analysed to determine natural and artificial radioactivity in those parts (leaves, fruits, seeds, roots, peduncles, flowers, barks, berries, thallus) used generally as remedies. The radionuclides were determined by alpha (238U, 210Po) and gamma (214Pb-Bi, 210Pb, 40K and 137Cs) spectrometry. 238U ranged between dry-1; 210Po between dry-1; 214Pb-214Bi between dry-1; 210Pb between dry-1; 40K between 66.2 and 3582.0 Bq kgdry-1; 137Cs between dry-1. The percentage of 210Po extraction in infusion and decoction was also determined; the arithmetical mean value of percentage of 210Po extraction resulted 20.7 ± 7.5.

  2. Artificial radioactivity on the coasts of Northern Ireland

    In Northern Ireland, measurements of artificial radioactivity have been made in inshore seawater, beach sand and mud, sea spray, the air and material deposited from the air, and in coastal soil. The objective was to determine the levels in the coastal environment and also to assess the magnitude of transport of radioactivity from sea to land in sea spray. The results would provide a basis for the development of a model describing sea to land transfer, and allowing the resulting population exposure to be assessed. The results showed the presence of plutonium isotopes, 241Am and 137Cs in some samples of each of the media measured, but concentrations were low in all cases. Large variation in the concentrations in seawater and beach sediment were attributed to variations in dispersion and in the characteristics of the sediment. Sea to land transfer of actinides was detected in samples of sea spray and in air and deposition measurements. Only at some sites on the east coast could the resulting accumulation in soil close to the beach be distinguished from fallout. Following May 1986 137Cs from Chernobyl could be detected in air and in atmospheric deposition. A preliminary assessment of the exposure of the population to the actinides and 137Cs in all the media showed that the resulting dose is a small fraction of the recognised limit. (author)

  3. Problem of Induced Radioactivity in Food Products

    Radioactivity induced by irradiation of foods is caused by the interaction of high-energy radiation with nuclei of food elements. The induced activity is a function of the applied energy, the dose, the sample thickness and the chemical composition of the food. A prime condition for a prediction of the radioactivity induced by irradiation is therefore the knowledge of the chemical composition of the sample. Suitable experimental methods of food analysis are described. Electron and gamma rays are equivalent in the production of induced radioactivity. In the energy range of 0.05 to 10 MeV induced radioactivity is due to stimulation of isomers in (γ, γ')-reactions. In this range the 107Ag(γ, γ') 107mAg-reaction is responsible for the greatest part of the induced activity. Using a new simplified method of calculation the expected induced radioactivity is estimated, and it is concluded that the activity of these isomers presents no health hazard. By the same method the induced radioactivity in the energy range above 10 MeV, where besides ((γ, γ') reactions the possibility of (γ, n) reactions exists, is calculated for the principal foodstuffs. Methods for experimental verification of calculated activities are discussed. The magnitude of induced radioactivity due to single elements is compared with the total maximal permissible concentration (MPC) of nuclides in foods (10-7 μCi/g food). Factors which determine the maximum permissible radiation energy and dose are discussed. (author)

  4. Nuclear chemistry fifty years after the discovery of artificial radioactivity

    In January 1934, the observation and the chemical identification of radiophosphorus as a reaction product in the bombardment of Aluminium by alpha particles have been the first step of a new scientific branch: Nuclear Chemistry. We describe here how this discovery in itself contains the frame of all the development which has followed. It consisted in four stages, each of them being a crucial starting point. The first one is the possibility for a total balance of the nuclear reaction in the exit channels, so that reaction mechanisms can be studied. The second, the most important perhaps, is the opening of nuclear synthesis. Nuclear chemists can now interfere into nuclear matter and instead of staying as observers of the radioactive decays of natural isotopes, they were able to build up a numerous chart of various nuclear species, going step by step further and further away from the nuclear stability conditions. The third aspect of the discovery was the appearance of a new mode of radioactive decay with the production of the first particle an antimater. 50 years later, the instability due to a much larger excess of protons is known to induce the proton emission radioactivity for new species like 109I or 115Cs, in the vicinity of proton unstability. Finally, the last point, so fertile for the future, was the observation of a neutron in the exit channel, so that neutron fluxes could result from alpha induced nuclear reactions and became such a strong tool for the production of transuranium elements and for nuclear fission. In the present survey, the wide interest of the second point, i.e. the nuclear synthesis, is emphasized, as well as the huge change in the technical methods

  5. Artificial radioactivity in tide washed pastures in south west Scotland

    A study has been carried out to determine the impact of Sellafield discharges on the levels of radioactivity in tide washed pastures in south west Scotland. The likely areas of tidal inundations along the Nith, Urr, Dee, Fleet and Cree (including nearby Bladnoch) rivers were assessed using maps and aerials photographs. These were then visited and gamma radiation measurements taken at regular intervals to enable the external dose from anthropogenic nuclides to be estimated. A further survey followed where soil cores were taken from the areas on each river where the external dose appeared highest and analysed for a range of artificial radionuclides. The levels of 137Cs, 134Cs, 238Pu, 239+240Pu and 241Am found, although small, were clearly in excess of the background from other sources. A habit survey was carried out to provide site specific information of tide washed pasture usage, which, with the spatial radionuclide data was used to estimate doses to appropriate critical groups. The maximum annual dose calculated to arise was 60 μSv which is less than 6% of the ICRP principal dose limit of 1 mSv. (author)

  6. Multiprotocol-induced plasticity in artificial synapses.

    Kornijcuk, Vladimir; Kavehei, Omid; Lim, Hyungkwang; Seok, Jun Yeong; Kim, Seong Keun; Kim, Inho; Lee, Wook-Seong; Choi, Byung Joon; Jeong, Doo Seok

    2014-12-21

    We suggest a 'universal' electrical circuit for the realization of an artificial synapse that exhibits long-term plasticity induced by different protocols. The long-term plasticity of the artificial synapse is basically attributed to the nonvolatile resistance change of the bipolar resistive switch in the circuit. The synaptic behaviour realized by the circuit is termed 'universal' inasmuch as (i) the shape of the action potential is not required to vary so as to implement different plasticity-induction behaviours, activity-dependent plasticity (ADP) and spike-timing-dependent plasticity (STDP), (ii) the behaviours satisfy several essential features of a biological chemical synapse including firing-rate and spike-timing encoding and unidirectional synaptic transmission, and (iii) both excitatory and inhibitory synapses can be realized using the same circuit but different diode polarity in the circuit. The feasibility of the suggested circuit as an artificial synapse is demonstrated by conducting circuit calculations and the calculation results are introduced in comparison with biological chemical synapses. PMID:25373422

  7. Investigation and assessment on artificial radioactivity level in waters in Shanghai

    Investigation and assessment on artificial radioactivity level in river, lake, reservoir and tap waters in Shanghai from 1989?1991 have been done. Totally 45 samples from 15 measuring sites in dry and wet seasons were collected. The results showed that the radioactivity level of various water bodies in Shanghai were within normal background value

  8. Radiation exposure due to artificial and natural radioactive nuclides

    The teaching unit presents information on the radiation exposure emanating from foodstuffs and natural or artificial nuclides in our environment. The material is prepared for teaching purposes, also indicating means of action for prevention of radiation exposure. (DG)

  9. Natural and induced radioactivity in food

    One of the first questions often asked about irradiated food is whether it is radioactive. Not many people understand that food and any natural substance contains natural radioactivity which can be measurable. It is therefore important to put the issue on natural radioactivity and possible induced radioactivity in food in perspective. While there is a clear consensus among the scientific community that no radioactivity is induced when food is irradiated by gamma rays from cobalt-60 or cesium-137, electron generated by a machine with energy less than 10 million electron volt (MeV) or X rays produced generated by a machine with energy less than 5 MeV. However, data to this effect were published many years ago and are not easy to find. As food irradiation is gaining wide acceptance in many countries, it was considered timely to compile data on natural and induced radioactivity in food into one document. We are grateful to A. Brynjolfsson, one of the few experts who have the knowledge on this subject as well as wide experience on food irradiation, who collected, compiled and evaluated all data on this subject into one report. This publication provides clear explanations not only why radioactivity cannot be induced in food irradiated by radiation sources mentioned above but to what extent the increase in dose or energy level of radiation sources would induce significantly radioactivity in food. The compilation of such data was prompted by a desire to increase the energy limit and the absorbed dose based on the need to irradiate thicker samples of food and to use sterilizing dose up to 60 kGy. This publication concluded that the increase in radiation background dose from consumption of food irradiated to an average dose up to 60 kGy with gamma rays from cobalt- 60 or cesium-137, with 10 MeV electrons or with 5 MeV X rays is insignificant. In addition, food irradiated with X ray with energy up to 7.5 MeV to a dose of 30 kGy has radioactivity well below natural radioactivity in unirradiated food. There are no adverse effect from consumption of irradiated food which contains radioactivity well below background level. This publication should provide valuable information to anyone who has interest in food irradiation especially regulatory authorities for food safety and radiation applications as well as to consumers who might be interested in scientific matters of irradiated food

  10. Concrete structure for controlling induced radioactivity

    If neutron fluxes generated from a radiation source such as a nuclear reactor are irradiated to concrete structures, induced radioactivity is produced. Since the induced radioactivity continues to release radiation-rays (gamma rays) even when the irradiation of neutrons is terminated, there is a problem of operators' exposure, etc. particularly upon opening a nuclear reactor in periodical inspection. In the present invention, silicon rubber neutron shielding layers or polyethylene neutron shielding layers are formed at the surface of the concrete structures of a nuclear facility on the side of the radiation source. The countings of ?-rays from these shielding material layers are about 1/100 of usual concretes. Accordingly, neutron irradiation to the concrete structures can be prevented, by which induced radioactive containing long half-life time nuclides from the concrete structures can be suppressed. (T.M.)

  11. Natural and artificial alpha radioactivity of platinum isotopes

    The partial alpha emission half-life for the naturally occurring and artificially produced platinum isotopes (Z=78) was evaluated in the framework of a semiempirical, one-parameter model based on the quantum mechanical tunneling mechanism through a Coulomb-plus-centrifugal-plus-overlapping potential barrier within the spherical nucleus approximation. This approach has been shown to be exceptionally well suited (to a level of 90% of the cases within a factor of less than 2) to fitting the existing data covering nearly 23 orders of magnitude in the measured half-lives. Exceptions were found for the artificial alpha transition from 176Pt to the excited level of 172Os, and the rare, quite recently observed, case of the natural alpha decay of 190Pt to the first excited level of 186Os. Comparison with other alpha decay half-life estimates for the naturally occurring platinum isotopes has also been presented.

  12. Daily measurements of natural and artificial radioactivity in 1962

    Daily numerical results of measures concerning β activity of the air, either from natural, owing to thoron, of from artificial, owing to active aerosols origin, will be found in this statement. The all results are expressed in μμcurie/m3 of air. Proceedings of measure and technic of standardization, which were the matter of anterior papers, have not been discussed once more here. (author)

  13. NATURAL AND ARTIFICIAL RADIOACTIVITY IN IMPORTED FISHERY PRODUCTS

    R. Cavallina

    2013-02-01

    Full Text Available Considering the growing public concern over marine environmental quality, a program of monitoring radionuclids in imported fishery products has been established. The analyses have been performed by gamma spectrometry allowing the rapid detection of many artificial radionuclides such as 137Cs, 134Cs and 40K. The data obtained show Cs radionuclides levels within expected limits. The detection of natural radionuclide K showed different levels in the same fishery product as they came from different sea areas.

  14. Daily measurements of natural and artificial radioactivity in 1961 (1962)

    Daily numerical results of measures concerning β activity of the air, either from natural, owing to thorium, or from artificial, owing to active aerosols origin, will be found in this statement. The all results are expressed in pico curie/m3 of air. Proceedings of measure and techniques of standardization, which were the matter of anterior papers, have not been discussed once more here. (author)

  15. The artificial radioactivity in Bechet-Dabuleni area, five years of survey

    The Bechet-Dabuleni area is placed in the southern part of Romania, in the Danube zone, near the Nuclear Power Plant from Kozlodui (Bulgaria). Here there is a very important agricultural area, with small and also big farms where for irrigation the Danube water is used. The purpose of the study was was long term surveillance of the artificial radioactivity for the main foodstuffs. It has been investigated the radioactive content of the following foodstuffs from this area: vegetables (potatoes, carrots, onion, etc.), fruits (apples, pears, apricots, peaches) and cereals (wheat, barley). It has also been determined the radioactive content of the irrigating water from the Danube River. (author)

  16. Levels of artificial radioactivity in milk samples from two different ecosystems of the Extremadura region

    The levels of artificial radioactivity were determined in goat and cow milk samples collected from 1988 to 1990 in centres of population belonging to two Extremadura ecosystems in which there are situated the Almaraz nuclear power plant and the nuclear waste disposal site of El Cabril. (author)

  17. Investigation and assessment on artificial radioactivity level in soil in Shanghai

    Artificial radioactivity level in soil of Shanghai and in sediment of Huangpu River have been investigated during 1989 to 1990. The results showed that the levels were about the same as that in other places over China. The annual individual effective dose of 137Cs in soil of Shanghai was estimated

  18. Induced radioactivity due to high energy radiation

    In high energy radiation facilities, the reaction called ''Spallation'' (nuclear spallation) becomes to contribute greatly to the production of induced radioactivity in the facility structures, water and air, besides thermal neutron capture reaction and the reaction accompanied by nucleon release due to fast neutrons. Spallation products have three features. The first is the abundance of the kinds of nuclides produced, the second is that the major part of the products are positron emitters, and the third is that the most products have short life. If the estimation of the radioactivity intensity and amount of spallation products is intended from the viewpoint of radiation protection, experimental values or the semi-empirical equation determined on the basis of experimental values should be used. Rudstam formula is well-known as such a semi-empirical equation. Though it is important for health physics to estimate the induced activity production due to high energy radiation quantitatively and as accurately as possible, the quantitative estimation is practically quite difficult. The problems in radiation control caused by induced activity include the spatial dose rate in operation and during shut down, the radioactive contamination of workers and the treatment and disposal of activated water and air. It is necessary in the actual radiation control duties to develop the monitoring techniques or radioactivity concentration, because the routine monitoring techniques seem to have not yet been established, and the calibration and assessment procedures seem to leave room for the improvement. (Wakatsuki, Y.)

  19. Evaluation of induced radioactivity in 10 MeV-Electron irradiated spices, (2)

    In order to check radioactivity of beta-emmitters produced by (γ, n) reactions which could occur at energies up to 10 MeV, black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy. Beta-rays were counted using a 2π gas flow counter and a liquid scintillation counter. Any induced radioactivity could not be detected in irradiated samples. When inorganic compounds containing the nuclides in the list were artificially added in the samples and were irradiated, the β-activities were detected. From the amount of observed radioactivities of β-emmitters produced in the compounds as photonuclear products, it is concluded that the induced radioactivity in natural samples by 10 MeV-electron irradiation were far smaller than natural radioactivity from 40K contained in the samples and, hence, its biological effects should be negligible. (author)

  20. Evolution of artificial radioactivity in Channel sediments, 1971-1975

    The radioactivity of sediments of the Channel and Atlantic shores was measured by Ge-Li diode spectrometry on gross and fine samples collected from 1971 to 1975. The effects of the fuel reprocessing plant at La Hague, the central point of the monitored area, were clearly demonstrated only from 1974 on the gross fraction for 106Ru, 95Zr, 125Sb, 144Ce, and on the fraction smaller than 28μm for 106Ru, 95Zr, 125Sb, 144Ce, 65Zn, 103Ru, 110Ag, 134Cs, 141Ce, 155Eu. As regards 137Cs, in spite of rather significant discharges, no evident effects could be detected by measurements. Some aspects of in situ retention processes of radionuclides on sediments were demonstrated by comparing sediment activities versus discharged activities and by considering desorption characteristics

  1. Detecting artificial airborne radioactivity: on-line monitoring of external dose rate near an aerosol filter

    An early warning method based on external dose rate monitoring near an aerosol filter can be used to detect artificial airborne radioactivity. A theory is presented for calculating the external dose rate in the measurement geometry involved. Airborne radionuclides and radionuclides collected by the filter and deposited on the ground are considered. Delay time from the arrival of a radioactive cloud to a tentative warning level of 0.4?Gy.h-1 is calculated for two cases: for a constant activity concentration of 137Cs and for a group of fission products. The simulations indicate that, in terms of activity concentrations, a warning level of -3 of artificial airborne radionuclides can be attained. This activity concentration corresponds roughly to an external dose rate of 1 nG.h-1, which is about 2 orders of magnitude below a typical, natural, ground-level dose rate. (Author)

  2. Monitoring of natural and artificial radioactivity in integrated iron and steel flux

    Possible concentration of radioactivity in iron and steel process implies necessity of radiometric measurements to identify the natural and/or artificial radioisotopes in iron, steel, and raw materials, intermediate, finite products and offal. This paper presents the technology of measurements using single- and multi- channel analyser with high resolution gamma spectrometry system. A low cost measurement for selecting potentially interesting radioactive samples is first performed and then a complete spectrometric analysis is undertaken. We checked the procedure for several descendants of natural series (e.g. 214 Pb, 214 Bi, 238 U, and 40 K) and several artificial isotopes currently used in iron and steel process control (e.g. 241 Am, 60 Co, 137 Ce, and 110 Ag). (Author)

  3. Detection of pulmonary aspiration by radioactive measurements of bronchial material in artificially ventilated infants

    Detection of pulmonary aspiration of gastric contents by radioactive measurements of bronchial material was performed in 13 artificially ventilated infants (14 studies) after ingestion of 99m-technetium sulfure colloide. 10/13 had strong clinical suspicion of recurrent pulmonary aspiration. 10 out of 14 examinations were positive (71%). This technique is more sensitive than scintigraphic methods described in literature and particularly adapted to these patients

  4. Metal Complexes Containing Natural and and Artificial Radioactive Elements and Their Applications

    Kharissova, Oxana V.; Miguel A. Mndez-Rojas; Boris I. Kharisov; Ubaldo Ortiz Mndez; Perla Elizondo Martnez

    2014-01-01

    Recent advances (during the 20072014 period) in the coordination and organometallic chemistry of compounds containing natural and artificially prepared radionuclides (actinides and technetium), are reviewed. Radioactive isotopes of naturally stable elements are not included for discussion in this work. Actinide and technetium complexes with O-, N-, N,O, N,S-, P-containing ligands, as well ?-organometallics are discussed from the view point of their synthesis, properties, and main application...

  5. Artificial intelligence methods applied for quantitative analysis of natural radioactive sources

    Highlights: ► Basic description of artificial neural networks. ► Natural gamma ray sources and problem of detections. ► Application of neural network for peak detection and activity determination. - Abstract: Artificial neural network (ANN) represents one of artificial intelligence methods in the field of modeling and uncertainty in different applications. The objective of the proposed work was focused to apply ANN to identify isotopes and to predict uncertainties of their activities of some natural radioactive sources. The method was tested for analyzing gamma-ray spectra emitted from natural radionuclides in soil samples detected by a high-resolution gamma-ray spectrometry based on HPGe (high purity germanium). The principle of the suggested method is described, including, relevant input parameters definition, input data scaling and networks training. It is clear that there is satisfactory agreement between obtained and predicted results using neural network.

  6. Robust Type-specific Hemisynapses Induced by Artificial Dendrites

    Kim, Eun Joong; Jeon, Chang Su; Lee, Soo Youn; Hwang, Inseong; Chung, Taek Dong

    2016-01-01

    Type-specificity of synapses, excitatory and inhibitory, regulates information process in neural networks via chemical neurotransmitters. To lay a foundation of synapse-based neural interfaces, artificial dendrites are generated by covering abiotic substrata with ectodomains of type-specific synaptogenic proteins that are C-terminally tagged with biotinylated fluorescent proteins. The excitatory artificial synapses displaying engineered ectodomains of postsynaptic neuroligin-1 (NL1) induce the formation of excitatory presynapses with mixed culture of neurons in various developmental stages, while the inhibitory artificial dendrites displaying engineered NL2 and Slitrk3 induce inhibitory presynapses only with mature neurons. By contrast, if the artificial dendrites are applied to the axonal components of micropatterned neurons, correctly-matched synaptic specificity emerges regardless of the neuronal developmental stages. The hemisynapses retain their initially established type-specificity during neuronal development and maintain their synaptic strength provided live neurons, implying the possibility of durable synapse-based biointerfaces. PMID:27072994

  7. Robust Type-specific Hemisynapses Induced by Artificial Dendrites

    Kim, Eun Joong; Jeon, Chang Su; Lee, Soo Youn; Hwang, Inseong; Chung, Taek Dong

    2016-04-01

    Type-specificity of synapses, excitatory and inhibitory, regulates information process in neural networks via chemical neurotransmitters. To lay a foundation of synapse-based neural interfaces, artificial dendrites are generated by covering abiotic substrata with ectodomains of type-specific synaptogenic proteins that are C-terminally tagged with biotinylated fluorescent proteins. The excitatory artificial synapses displaying engineered ectodomains of postsynaptic neuroligin-1 (NL1) induce the formation of excitatory presynapses with mixed culture of neurons in various developmental stages, while the inhibitory artificial dendrites displaying engineered NL2 and Slitrk3 induce inhibitory presynapses only with mature neurons. By contrast, if the artificial dendrites are applied to the axonal components of micropatterned neurons, correctly-matched synaptic specificity emerges regardless of the neuronal developmental stages. The hemisynapses retain their initially established type-specificity during neuronal development and maintain their synaptic strength provided live neurons, implying the possibility of durable synapse-based biointerfaces.

  8. Development of artificial radioactivity in the French environment during the past 50 years and related doses; effect of the current operation of nuclear facilities

    The activities of artificial radionuclides in the environment have being strongly decreasing since 50 years. Nowadays the activities of 3H and 14C widely predominate, but they cannot be still considered as artificial radionuclides, except nearby the nuclear installations where they constitute the most abundant radioactive releases. In terrestrial environment this influence is limited to the surroundings of 5 sites, although most of nuclear sites and nuclear medical centers are involved in the contamination of the aquatic environment downstream the releases and in the Channel. Since 1987 the doses to the French population have been mainly induced by 14C and 137Cs. (author)

  9. 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

    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)

  10. 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

    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)

  11. The use of artificial sorbents for radioactivity monitoring of water basins of Belarus

    A possibility of using artificial sorbents to study radionuclide behaviour in a water has been shown. With these sorbents a pollution degree has been determined in a water of lakes of different types with a minimal economical expenditures and operatively. Inconstancy of influenced factors in summer time doesn't permit to determine the activity of cesium 137 in a water authentically, but it gives the opportunity to reveal the pattern of radioactive cesium distribution by the area of lake aquatic system and by it's depth and so to permit the monitoring of lake basins station

  12. Standard test bench for calibrating instruments used to measure natural or artificial radioactive airborne particulates

    An aerodynamic calibration device, known as ICARE, has been set up in France at the Saclay Research Centre to certify instruments used to measure natural or artificial airborne radioactive particulate contamination or radon. ICARE can calibrate passive detectors and monitors with sampling air flow-rates of less than 60 m3/h. The adjustment of such parameters as 222Rn daughters volume activity, attached fraction and equilibrium factor, and the volume activity and size of ? or ? emitter carrying aerosols, allows realistic conditions to be obtained. ICARE complies with monitor test method standard currently under development by the International Electrotechnical Commission

  13. Standard test bench for calibrating instruments used to measure natural or artificial radioactive airborne particulates

    An aerodynamic calibration device, known as ICARE, has been set up in France at the Saclay Research Centre to certify instruments used to measure natural or artificial airborne radioactive particulate contamination or radon. ICARE can calibrate passive detectors and monitors with sampling air flow-rates of less than 60 m3/h. The adjustment of such parameters as 222Rn daughters volume activity, attached fraction and equilibrium factor, and the volume activity and size of ? or ? emitter carrying aerosols, allows realistic conditions to be obtained. ICARE complies with monitor test method standard currently under development by the International Electrotechnical Commission. (author)

  14. Individual and social risk due to natural and artificial environmental radioactivity in Greece

    Two sets of cases of natural versus artificial radioactivity risk assessment for the Greek population are presented in this paper. In the first set, the variations of the individual risk due to the external exposure to the terrestrial gamma rays of natural origin and those of the 137Cs deposited after the Chernobyl accident are compared. In the second set the risk due to the internal exposure of the patients of the major Greek radon spas is compared with the risk of the Athens region inhabitants resulting from a characteristic accident of the Greek Research Reactor. (author)

  15. Monitoring natural and artificial radioactivity enhancement in the Aegean Sea using floating measuring systems

    In the present work, the enhancement of radioactivity due to rainfall in the Aegean Sea using floating measuring systems was observed and quantified. The data were acquired with a NaI underwater detection system, which was installed on a floating measuring system at a depth of 3 m. The results of natural and artificial radioactivity are discussed taking into account the rainfall intensity and wind direction. The activity concentration of 214Bi increased up to (991102) Bq/m3 after strong rainfall in the North Aegean Sea in winter (humid period) with east wind direction. On other hand, the maximum activity concentration reached the level of (11010) Bq/m3 in summer (dry period) during south winds

  16. Results of concentration measurements of artificial radioactive aerosols in the lower atmosphere

    This report gives the results of the measurements of artificial gross-β-radioactivity in aerosols in the lower atmosphere; these measurements have been made by the Electronic Physics Service of the Electronic Department, and by the Atmospheric Physics Laboratory of the Paris Science Faculty. The measurements were begun in September 1956 and were continued in an increasing number of stations both in France and in the rest of the world. The present report deals with the period up to the end of august 1961, that is up to the end of the nuclear moratorium. After recalling the constitution and the properties of radioactive aerosols present in the atmosphere, the authors describe the measurement methods, estimate their accuracy and discuss various aspects of the results. (authors)

  17. Solutes problems and main results in the area of natural and artificial radioactivity

    The list of research problems and main results in natural and artificial radioactivity monitoring in the Slovak Republic is presented.The mean values of 78 000 measurements of natural radioactivity are: potassium 1.6 %, uranium 3.3 ppm, thorium 9.4 ppm, relation of Th/U 2.8, Th/K 5.8, and U/K 2.1. Mean dose rate for Slovakia is 63.3 nGy/h.The mean activity of cesium-137, measured on 5500 points, is 2200 Bq/m2 that is mean dose rate 3.5 nGy/h. The arithmetic mean of concentration of uranium in underground waters of Slovakia is .0034 mg/dm3, mean volume activity of radium 222 is 0.048 Bq/dm3 and of radon-222 is 15.51 Bq/dm3

  18. Artificial neural network application in isotopic characterization of radioactive waste drums

    One of the most important aspects to the development of the nuclear technology is the safe management of the radioactive waste arising from several stages of the nuclear fuel cycles, as well as from production and use of radioisotope in the medicine, industry and research centers. The accurate characterization of this waste is not a simple task, given to its diversity in isotopic composition and non homogeneity in the space distribution and mass density. In this work it was developed a methodology for quantification and localization of radionuclides not non homogeneously distributed in a 200 liters drum based in the Monte Carlo Method and Artificial Neural Network (RNA), for application in the isotopic characterization of the stored radioactive waste at IPEN. Theoretical arrangements had been constructed involving the division of the radioactive waste drum in some units or cells and some possible configurations of source intensities. Beyond the determination of the detection positions, the respective detection efficiencies for each position in function of each cell of the drum had been obtained. After the construction and the training of the RNA's for each developed theoretical arrangement, the validation of the method were carried out for the two arrangements that had presented the best performance. The results obtained show that the methodology developed in this study could be an effective tool for isotopic characterization of radioactive wastes contained in many kind of packages. (author)

  19. Radioactivity of natural and artificial building materials – a comparative study

    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 226Ra, 232Th and 40K 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 226Ra content. Natural, i.e. adobe and also brick samples contain higher amount of 40K 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 to the limitations of the internal hazard considerations based on only measured 226Ra activity concentrations without direct radon measurements. Our data are compared to those obtained in other countries and they provide a good basis to expand the database of radioactivity of building materials and gives information about the safety and situation of the building material industry in this central region of Europe. -- Highlights: ► Radionuclide content and various hazard indices of 40 building materials are studied. ► Data are compared to each other and to results obtained in other studies. ► Radon hazard portion is defined. ► Seven samples exceed any of the thresholds, but three is considered to be hazardous

  20. Artificial and natural radioactivity in edible mushrooms from Sao Paulo, Brazil

    Environmental biomonitoring has demonstrated that organisms such as crustaceans, fish and mushrooms are useful to evaluate and monitor both ecosystem contamination and quality. Particularly, some mushroom species have a high capacity to retain radionuclides and some toxic elements from the soil and the air. The potential of mushrooms to accumulate radionuclides in their fruit-bodies has been well documented. However, there are no studies that determine natural and artificial radionuclide composition in edible mushrooms, in Brazil. Artificial (137Cs) and natural radioactivity (40K, 226Ra, 228Ra) were determined in 17 mushroom samples from 3 commercialized edible mushroom species. The edible mushrooms collected were Agaricus sp., Pleurotus sp. and Lentinula sp. species. The activity measurements were carried out by gamma spectrometry. The levels of 137Cs varied from 1.45 0.04 to 10.6 0.3 Bq kg?1, 40K levels varied from 461 2 to 1535 10 Bq kg?1, 226Ra levels varied from 14 3 to 66 12 Bq kg?1 and 228Ra levels varied from 6.2 0.2 to 54.2 1.7 Bq kg?1. 137Cs levels in Brazilian mushrooms are in accordance with the radioactive fallout in the Southern Hemisphere. The artificial and natural activities determined in this study were found to be below the maximum permissible levels as established by national legislation. Thus, these mushroom species can be normally consumed by the population without any apparent risks to human health. - Highlights: ? 137Cs, 40K, 226Ra and 228Ra in edible mushroom samples. ? There are very few data about natural radionuclides in mushrooms. ? The radionuclide activities were below the national maximum permissible levels. ? Mushrooms can be consumed by the population without any apparent risks.

  1. OBSERVATIONAL SCAN-INDUCED ARTIFICIAL COSMIC MICROWAVE BACKGROUND ANISOTROPY

    Reliably detecting the cosmic microwave background (CMB) anisotropy is of great importance in understanding the birth and evolution of the universe. One of the difficulties in CMB experiments is the domination of measured CMB anisotropy maps by the Doppler dipole moment from the motion of the antenna relative to the CMB. For each measured temperature, the expected dipole component has to be calculated separately and then subtracted from the data. A small error in dipole direction, antenna pointing direction, sidelobe pickup contamination, and/or timing synchronism can introduce a significant deviation in the dipole-cleaned CMB temperature. After a full-sky observational scan, the accumulated deviations will be structured with a pattern closely correlated with the observation pattern with artificial anisotropies, including artificial quadrupole, octupole, etc., on large scales in the final CMB map. Such scan-induced anisotropies on large scales can be predicted by the true dipole moment and observational scan scheme. Indeed, the expected scan-induced quadrupole pattern of the Wilkinson Microwave Anisotropy Probe (WMAP) mission is perfectly in agreement with the published WMAP quadrupole. With the scan strategy of the Planck mission, we predict that scan-induced anisotropies will also produce an artificially aligned quadrupole. The scan-induced anisotropy is a common problem for all sweep missions and, like the foreground emissions, has to be removed from observed maps. Without doing so, CMB maps from COBE, WMAP, and Planck are not reliable for studying the CMB anisotropy.

  2. Survey and assessment on artificial radioactivity level in Shanghai atmospheric environment

    Survey of artificial radioactivity level in Shanghai atmospheric environment took place during Sept. 1989 to Nov. 1991. The result showed that the total ?-radioactivity concentration of aerosol in one-day samples and seven-day samples were 9.3 x 10-2 Bq/m3 and 2.6 x 10-2 Bq/m3 respectively, among which the concentrations of 90Sr-6 Bq/m3, 137Cs-5 Bq/m3; total ?-radioactivity in precipitation was 0.78 Bq/m3, among which 90Sr was 1.6 x 10-2 Bq/m2. d, 137Cs-3 Bq/m2. d, tritium vapor was 0.09 Bq/m3. The result of statistical analysis and assessment showed that there were no obvious differences at sampling points around Shanghai Municipality, but the seasonal variation showed that in the spring and winter seasons, the concentration was higher than that in the summer and autumn seasons

  3. Evaluation of induced radioactivity in 10 MeV-Electron irradiated spices, (2); [beta]-ray counting

    Katayama, Tadashi; Furuta, Masakazu; Shibata, Setsuko; Matsunami, Tadao; Ito, Norio; Mizohata, Akira; Toratani, Hirokazu (Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology); Takeda, Atsuhiko

    1994-02-01

    In order to check radioactivity of beta-emmitters produced by ([gamma], n) reactions which could occur at energies up to 10 MeV, black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy. Beta-rays were counted using a 2[pi] gas flow counter and a liquid scintillation counter. Any induced radioactivity could not be detected in irradiated samples. When inorganic compounds containing the nuclides in the list were artificially added in the samples and were irradiated, the [beta]-activities were detected. From the amount of observed radioactivities of [beta]-emmitters produced in the compounds as photonuclear products, it is concluded that the induced radioactivity in natural samples by 10 MeV-electron irradiation were far smaller than natural radioactivity from [sup 40]K contained in the samples and, hence, its biological effects should be negligible. (author).

  4. Determination of the natural and artificial radioactivity of a selection of traditional Mexican medicinal herbs by gamma spectrometry

    This work presents the results of a gamma spectrometry analysis of 30 traditional Mexican medicinal herbs. The analysis was carried out using low level background shielding, a hyper-pure germanium detector, and a multichannel analyzer system. Natural and artificial radioactivity concentration from 226Ra (through 214Pb and 214Bi), 228Th (through 208Tl), 228Ra (through 228Ac), 40K, and 137Cs were determined in this analysis. The results show low concentration levels of natural radioactivity and no artificial radionuclides, and different contents of natural 40K, in the studied medicinal herbs. These low concentration levels of natural radionuclides, cannot be consider a health risk for common consumers. (author)

  5. Electromagnetically induced transparency on a single artificial atom

    Abdumalikov, Jr., A. A.; Astafiev, O.; Zagoskin, A. M.; Pashkin, Yu. A.; Nakamura, Y.; Tsai, J. -S.

    2010-01-01

    We present experimental observation of electromagnetically induced transparency (EIT) on a single macroscopic artificial "atom" (superconducting quantum system) coupled to open 1D space of a transmission line. Unlike in a optical media with many atoms, the single atom EIT in 1D space is revealed in suppression of reflection of electromagnetic waves, rather than absorption. The observed almost 100 % modulation of the reflection and transmission of propagating microwaves demonstrates full contr...

  6. Human Health Impact of Natural and Artificial Radioactivity Levels in the Sediments and Fish of Bonny Estuary, Niger Delta, Nigeria

    Bolaji B. Babatunde; Francis D. Sikoki; Ibitoruh Hart

    2015-01-01

    There is widespread contamination of the environment of the Niger Delta, which may include enhanced background levels of naturally occurring radioactive materials (NORM) due to oil production and rapid urbanization activities. Sediments and seafood from the Bonny estuary, Niger Delta, were collected for the purpose of determining baseline data on artificial and natural radioactivity and estimation of effective doses for the public due to ingestion of seafood from the study area. The highest a...

  7. The quick distinguishing of the artificial radioactive contamination of the air by ?-decay proportional method

    The principles of the distinction of artificial radioactive contamination of air by '?-decay proportional method' are described and a brief introduction to the instruments designed according to the principles of this method is given. From the data processing it is concluded as follows: The concentration of ?-aerosol is 7.49 Bq/m3 (approx 2.0 x 10-13Ci/L) sampling for one hour, the amount of sampling air is 3.36 m3. And 60 minutes after sampling, the determination level is 1.82 Bq/m3 (approx 4.9 x 10-14Ci/L). For 150 minutes duration, the level is 1.77 Bq/m3 (approx 4.8 x 10-14 C.Ci/L)

  8. Application of artificial neural networks on the characterization of radioactive waste drums

    The methodology consist of system simulation of drum-detector by Monte Carlo for obtention of counting efficiency. The obtained data were treated and a neural artificial network (RNA) were constructed for evaluation of total activity of drum. For method evaluation measurements were performed in ten position parallel to the drum axis and the results submitted to the RNA. The developed methodology showed to be effective for isotopic characterization of gamma emitter radioactive wastes distributed in a heterogeneous way in a 200 litters drum. The objective of this work as to develop a methodology of analyse for quantification and localization of radionuclides not homogeneous distributed in a 200 liters drum based on the mathematical techniques

  9. Avalanches and disorder-induced criticality in artificial spin ices

    We show that both square and kagome artificial spin ice systems exhibit disorder-induced nonequilibrium phase transitions, with power law avalanche distributions at the critical disorder level. The different nature of geometrical frustration in the two lattices produces distinct types of critical avalanche behavior. For the square ice, the avalanches involve the propagation of locally stable domain walls separating the two polarized ground states, and the scaling collapse agrees with an interface depinning mechanism. In contrast, avalanches in the fully frustrated kagome ice exhibit pronounced branching behaviors that resemble those found in directed percolation. The kagome ice also shows an interesting crossover in the power-law scaling of the avalanches at low disorder. Our results show that artificial spin ices are ideal systems in which to study nonequilibrium critical point phenomena. (paper)

  10. Radioactively induced noise in gas-sampling uranium calorimeters

    The signal induced by radioactivity of a U238 absorber in a cell of a gas-sampling uranium calorimeter was studied. By means of Campbell's theorem, the levels of the radioactively induced noise in uranium gas-sampling calorimeters was calculated. It was shown that in order to obtain similar radioactive noise performance as U-liquid argon or U-scintillator combinations, the α-particles from the uranium must be stopped before entering the sensing volume of gas-uranium calorimeters

  11. Monitoring artificial radioactivity in the Nordic countries. BER-2 final report

    This final report of the Nordic Nuclear Safety Research Project BER-2 gives detailed information on the monitoring of artificial radioactivity in the Nordic countries (Denmark, Finland, Iceland, Norway and Sweden). A comparison shows that for early warning the Nordic countries use a mix of stations measuring external gamma radiation and stations measuring airborne radioactivity. There is a trade-off between fast alarms and the sensitivity threshold. Total gamma measuring stations cannot detect increases smaller than the variations of normal background. Some stations, notably all Danish stations, are equipped with sodium iodide (NaI) type detectors, and operated in such a way that stray peaks due to an increase in the natural radon background can be subtracted. A Nordic Radiation Data Exchange System has been set up and tested on a trial basis. This system focuses on dose rate data from the automatic gamma monitoring stations. An important goal achieved in the project was to determine which data is essential, and to specify a common format for the data exchange. Various telecommunication methods have been tested, and the actual transfer of monitoring results between the Nordic countries was started. It is recommended as a future approach that every country appoint one organization with the responsibility of operating a national information data base, which can be commonly accessed from all the Nordic countries. A procedure for establishing a system of this type has been outlined

  12. Artificial neural networks modeling of radioactive contamination of the Techa river

    For analyzing the anomalously high radioactive contamination of the Techa river in August 2004, when the content of 90Sr in Muslyumovo section line exceeded 50 Bq/l, the dynamics of its concentration in water of the Techa river and the level of the V-11 water body were simulated using artificial neural networks. The conclusion was made about existence of a certain concealed factor actuating in certain time moments and resulting in essential water level decrease in the V-11 water body, which cannot be explained based on the precipitation and evaporation balance. Effect of the factor is closely related to water consumption in the left-bank canal. The assumption is made that concurring anomalously high radioactive contamination of the Techa river water in summer of 2004 and water level decrease in the V-11 water body, unaccountable from the balance of precipitation and evaporation, were due to discharge of contaminated water from the V-11 to the left-bank by-pass canal

  13. Metal Complexes Containing Natural and and Artificial Radioactive Elements and Their Applications

    Oxana V. Kharissova

    2014-07-01

    Full Text Available Recent advances (during the 2007–2014 period in the coordination and organometallic chemistry of compounds containing natural and artificially prepared radionuclides (actinides and technetium, are reviewed. Radioactive isotopes of naturally stable elements are not included for discussion in this work. Actinide and technetium complexes with O-, N-, N,O, N,S-, P-containing ligands, as well π-organometallics are discussed from the view point of their synthesis, properties, and main applications. On the basis of their properties, several mono-, bi-, tri-, tetra- or polydentate ligands have been designed for specific recognition of some particular radionuclides, and can be used in the processes of nuclear waste remediation, i.e., recycling of nuclear fuel and the separation of actinides and fission products from waste solutions or for analytical determination of actinides in solutions; actinide metal complexes are also usefulas catalysts forcoupling gaseous carbon monoxide,as well as antimicrobial and anti-fungi agents due to their biological activity. Radioactive labeling based on the short-lived metastable nuclide technetium-99m (99mTc for biomedical use as heart, lung, kidney, bone, brain, liver or cancer imaging agents is also discussed. Finally, the promising applications of technetium labeling of nanomaterials, with potential applications as drug transport and delivery vehicles, radiotherapeutic agents or radiotracers for monitoring metabolic pathways, are also described.

  14. Metal complexes containing natural and and artificial radioactive elements and their applications.

    Kharissova, Oxana V; Méndez-Rojas, Miguel A; Kharisov, Boris I; Méndez, Ubaldo Ortiz; Martínez, Perla Elizondo

    2014-01-01

    Recent advances (during the 2007-2014 period) in the coordination and organometallic chemistry of compounds containing natural and artificially prepared radionuclides (actinides and technetium), are reviewed. Radioactive isotopes of naturally stable elements are not included for discussion in this work. Actinide and technetium complexes with O-, N-, N,O, N,S-, P-containing ligands, as well π-organometallics are discussed from the view point of their synthesis, properties, and main applications. On the basis of their properties, several mono-, bi-, tri-, tetra- or polydentate ligands have been designed for specific recognition of some particular radionuclides, and can be used in the processes of nuclear waste remediation, i.e., recycling of nuclear fuel and the separation of actinides and fission products from waste solutions or for analytical determination of actinides in solutions; actinide metal complexes are also usefulas catalysts forcoupling gaseous carbon monoxide,as well as antimicrobial and anti-fungi agents due to their biological activity. Radioactive labeling based on the short-lived metastable nuclide technetium-99m ((99m)Tc) for biomedical use as heart, lung, kidney, bone, brain, liver or cancer imaging agents is also discussed. Finally, the promising applications of technetium labeling of nanomaterials, with potential applications as drug transport and delivery vehicles, radiotherapeutic agents or radiotracers for monitoring metabolic pathways, are also described. PMID:25061724

  15. The use and production of artificial radioactive isotopes in Hungary over the past 25 years

    The history of application of artificial radioactive isotopes is reviewed. The first isotope consignement arrived in Hungary in 1954. Between 1954 and 1957 appropriate laboratories were constructed, new techniques developed and specialists were trained. The central coordinating organ, the National Atomic Energy Committee, was founded in 1956. The Institute of Isotopes was established in 1959, the tasks of which include the production and distribution of radioactive preparations, extensive research for new types of radiation sources as well as the development of new methods for activity measurement. Between 1957 and 1970 the development and production of measuring instruments have become especially important. More and more conferences and meetings were organized, basis institutes with specialized programs were founded. The cooperation among the Comecon-countries has become extensive in the 1960-es; in the 1970-es the emphasis has been put on specific tasks. Nowadays more than 1000 different preparations and a total activity of approx. 17000 TBq are produced in a year. (L.E.)

  16. Study of the artificial radioactivity of the marine medium using gamma spectrometry (1962-1966)

    The results described in this study are relative to the artificial radioactivity of such elements as zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 and praseodymium-144 which were present in the atmospheric fallout between 1962 and 1964, and their incidence in superficial marine waters. Various physical, chemical or biological processes are studied by a high sensitivity gamma ray spectrometry technic, using those radioelements as 'tracers'. The change of state in sea water of an important fraction (about 50 per cent) of the radioactive particles going into the soluble phase - this phenomenon was not expected for those radioelements - controls the processes of accumulation in the planktonic biomass and the diffusion towards deeper waters. On the other hand, an 'in situ' spectrometry method is described. It enables the direct measurement in the sea of very low concentrations of some gamma ray emitters. The application of this method has made possible to carry out numerous observations in the surface waters of the Western Mediterranean sea and in the Bay of Biscay. It is shown that the mixing depth is closely connected to the depth of the thermocline. An accumulation process at this level is observed. The diffusion coefficients are similar to the thermal turbulent coefficient. The existence during several months of 'compartments' is established for the surface waters of the Bay of Biscay. From the establishment of the budget of fall-out, a comparative study shows that the rate of radioactive fallout on the maritime zone considered is always two to three times higher than on the neighbouring continental regions. Several explanations of this phenomenon are discussed. (author)

  17. Artificial neural networks in the evaluation of the radioactive waste drums activity

    The mathematical techniques are becoming more important to solve geometry and standard identification problems. The gamma spectrometry of radioactive waste drums would be a complex solution problem. The main difficulty is the detectors calibration for this geometry; the waste is not homogeneously distributed inside the drums, therefore there are many possible combinations between the activity and the position of these radionuclides inside the drums, making the preparation of calibration standards impracticable. This work describes the development of a methodology to estimate the activity of a 200 L radioactive waste drum, as well as a mapping of the waste distribution, using Artificial Neural Network. The neural network data set entry obtaining was based on the possible detection efficiency combination with 10 sources activities varying from 0 to 74 x 103 Bq. The set up consists of a 200 L drum divided in 5 layers. Ten detectors were positioned all the way through a parallel line to the drum axis, from 15 cm of its surface. The Cesium -137 radionuclide source was used. The 50 efficiency obtained values (10 detectors and 5 layers), combined with the 10 source intensities resulted in a 100,000 lines for 15 columns matrix, with all the possible combinations of source intensity and the Cs-137 position in the 5 layers of the drum. This archive was divided in 2 parts to compose the set of training: input and target files. The MatLab 7.0 module of neural networks was used for training. The net architecture has 10 neurons in the input layer, 18 in the hidden layer and 5 in the output layer. The training algorithm was the 'traincgb' and after 300 'epoch s' the medium square error was 0.00108172. This methodology allows knowing the detection positions answers in a heterogeneous distribution of radionuclides inside a 200 L waste drum; in consequence it is possible to estimate the total activity of the drum in the training neural network limits. The results accuracy depends on the way that the waste drum is divided and to the amount of intensities that it is interpolated between the minimum and maximum limits. The use of the Artificial Neural Networks associated to Monte Carlo Method showed to be efficient in the isotopic characterization of radioactive waste drums. (authors)

  18. Applicability of artificial intelligence to reservoir induced earthquakes

    Samui, Pijush; Kim, Dookie

    2014-06-01

    This paper proposes to use least square support vector machine (LSSVM) and relevance vector machine (RVM) for prediction of the magnitude (M) of induced earthquakes based on reservoir parameters. Comprehensive parameter (E) and maximum reservoir depth (H) are used as input variables of the LSSVM and RVM. The output of the LSSVM and RVM is M. Equations have been presented based on the developed LSSVM and RVM. The developed RVM also gives variance of the predicted M. A comparative study has been carried out between the developed LSSVM, RVM, artificial neural network (ANN), and linear regression models. Finally, the results demonstrate the effectiveness and efficiency of the LSSVM and RVM models.

  19. Ultracold Fermions in a Cavity-Induced Artificial Magnetic Field

    Kollath, Corinna; Sheikhan, Ameneh; Wolff, Stefan; Brennecke, Ferdinand

    2016-02-01

    We propose how a fermionic quantum gas confined to an optical lattice and coupled to an optical cavity can self-organize into a state where the spontaneously emerging cavity field amplitude induces an artificial magnetic field. The fermions form either a chiral insulator or a chiral liquid carrying chiral currents. The feedback mechanism via the dynamical cavity field enables robust and fast switching in time of the chiral phases, and the cavity output can be employed for a direct nondestructive measurement of the chiral current.

  20. Natural and artificial atmospheric radioactivity in aerosols collected in Barcelona (Spain)

    Radioactivity in the Barcelona area is continuously being measured at the Radioactivity Analysis Laboratory of the Institute of Energy Technologies, Technical University of Catalonia, as it is part of a Spanish Sparse network for radiation monitoring. High sensitivity measurements are made in this laboratory. Airborne particulate sampling is carried out by pumping air through polypropylene filters at a flow rate of 800 m3/h. Measurements of radionuclides were carried out by γ-ray spectrometric analysis of particulate samples collected weekly. The results for the naturally occurring 7Be, 210Pb, 40K, 214Bi, 214Pb, 228Ac and 208Tl and for the artificial radionuclide 137Cs, during the period from January 2001 to December 2004, are given in this report. The aim of the present in paper is to find the underlying causes of variations of radionuclide concentrations in the air Barcelona and the correlation with season, rainfall, airborne particulate material, wind speed and wind direction. The annual average values obtained for 7Be, 210Pb and 137Cs during the investigation period were in good agreement with those measured in other countries. During the investigation period, the radionuclides 212Pb and 208Tl, 214Bi and 214Pb, 7Be and 210Pb, correlate significantly with each other. The correlation coefficients obtained were 0.99, 0.73 and 0.71 respectively with a confidence level of 99%. 7Be and 210Pb concentrations show the same seasonal variation, with a tendency for a maximum concentration during summer months. An inverse relationship, was generally observed, between the 7Be, 210Pb, 40K and 137Cs concentrations and weekly rainfall, indicating washout of the atmospheric aerosol that carries these radionuclides

  1. Assessment of artificial radioactive contamination of Jeju soil through 137Cs concentration measurements

    Various artificial radioactive isotopes were distributed to the earth atmosphere due to the nuclear weapon tests in 1950's and 1960's and the NPP accident. Thus these radioactive isotopes are detected even in regions, which are away from nuclear facilities. In order to estimate these effects, this study measured the 137Cs concentrations in Jeju island. 137Cs was chosen as its relatively long half-life of 30.2 years makes the element last longer. Through the literature survey, the characteristics of the soil in Jeju were reviewed and eight sampling sites were selected by regional and soil-color groups. The soil samples were prepared by the standard sampling method. Using the HPGe detector and MCA(Multi-Channel Analyser), the gamma-ray spectrum analyses were carried out and the 137Cs concentrations were determined. Simultaneously, pH and O.M.C.(Organic Matter Content) analyses were performed as they are important factors affecting the 137Cs concentrations. The measured 137Cs concentrations spread 2.333-9.402 Bq/kg and the measurement errors were estimated to be 1.36%. These results seem to be similar to the national 137Cs level and correspond to about 1/2000 of the limiting values described in the Atomic Energy Act Decree, showing that the effects of 137Cs to human and environments are negligible. The 137Cs level correlated with the O.M.C. showed a clear proportionality. Thus the organic matter in soil absorbs 137Cs, limiting the mobility of 137Cs and resulting high 137Cs level. Also the comparisons of the results with similar study performed by KINS for nuclear facilities sites show the higher 137Cs concentrations of Jeju soil, which again can be explained by the high O.M.C. of Jeju soil as it had been formed by the volcanic activities and the volcanic ashes are less efficient in removing the organic matters

  2. Radioactivity

    This educative booklet give a general overview of radioactivity: history, structure of matter, radiations, radioactivity law, origin of radioactivity, radioactivity uses, radioprotection and measurement units. (J.S.)

  3. Artificial radionuclides in the ecosystems of the gulfs in the Kola peninsula and in the areas of radioactive wastes keeping

    The results of radioactive contamination investigations carried out in the Kola Peninsula gulf's ecosystems in the vicinity of the places of radioactive wastes keeping are presented. These investigations were conducted during 1994-2004 by specialists of the Murmansk Marine Biological Institute KSC RAS. The data on the artificial radionuclides contents in bottom sediments, water and hydrobiontes of the Kola, the Motovsky Bays and gulfs of the Barents Sea are presented. Coefficients values of caesium radionuclides distribution between water and bottom sediments of the Kola Bay obtained experimentally and developed on the basis of the data on the composition and amount of artificial radionuclides in bottom sediments classification of bays and gulfs are also given. (author)

  4. Simulation of induced radioactivity for Heavy Ion Medical Machine

    Jun-Kui, Xu; Wu-Yuan, Li; Wang, Mao; Jia-Wen, Xia; Xi-Meng, Chen; Wei-Wei, Yan; Chong, Xu

    2013-01-01

    For radiation protection and environmental impact assessment purpose, the radioactivity induced by carbon ion of Heavy Ion Medical Machine (HIMM) was studied. Radionuclides in accelerator component, cooling water and air at target area which are induced from primary beam and secondary particles are simulated by FLUKA Monte Carlo code. It is found that radioactivity in cooling water and air is not very important at the required beam intensity and energy which is needed for treatment, radionuclides in accelerator component may cause some problem for maintenance work, suitable cooling time is needed after the machine are shut down.

  5. Induced radioactivity in the ESRF storage ring.

    Berkvens, P

    2005-01-01

    The new French radiation protection legislation requires the definition of the zoning of accelerator facilities with respect to radioactive waste. This activation inside the ESRF 6 GeV storage ring is essentially due to photonuclear reactions. This paper describes the first results of Monte Carlo calculations that were started to prepare this zoning. The electron beam losses inside the storage ring, required to calculate saturation activities, are described. Results for the activation of the air inside the ring tunnel and of the cooling water are presented. The activation of accelerator components is illustrated with the results of the activation of the stainless steel vessels in a standard cell and in a cell with higher losses due to the presence of a vertical scraper. The amount of activation is compared with clearance levels given in the European directive 96/29/Euratom. PMID:16381770

  6. Preliminary results on artificial radioactivity and elemental content of samples from Black Sea

    During the international expedition of the research vessel Prof. Vodyanitskiy on the Black Sea, in December 1999, samples of sea water and sediment were collected and analyzed for elemental content and radioactivity. The cruise covered the mouths of the Dniester and Danube River, the Crimean coastal waters and the offshore area. The sediment, collected by an EPA Box corer was separated in layers. Sediment samples were analyzed by gamma spectroscopy for the artificial occurring radionuclide Cs-137. The concentration of some major, minor and trace elements was determined by X-ray fluorescence (XRF) technique. For the water samples, Cs-137 concentration varied between (26.3 ± 3.4) mBq/l and (41.2 ± 5.6) mBq/l for the surface water; a value of (9.9 ± 1.8) mBq/l was found for a deep water sample collected far offshore. The concentration of Sr-90 did not vary significantly from a station to another and was around 11 mBq/l. The concentration of tritium was low (between 24 and 7 T.U.), in the range reported in the recent literature. For all the sampling locations the maximum of the 137 Cs specific activity in sediment samples was found in the surface layer. In the samples collected from the stations 3 and 4, close to the mouths of Danube and Dniester Rivers, higher values up to (128 ± 6) Bq/kg were found. A similar elemental composition of sediment samples in the locations mentioned above was found. Cr and Ni were detected only in the sediment sample collected near the Crimean shore, and are probably correlated to the industrial discharges. (authors)

  7. Emanations and 'induced' radioactivity: from mystery to (mis)use

    The natural Rn isotopes were discovered within the period 1899-1902 and at that time referred to as emanations because they came out (emanated) of sources/materials containing actinium, thorium and radium, respectively. The (somewhat mysterious) emanations appeared to disintegrate into radioactive decay products which by depositing at solid surfaces gave rise to 'induced' radioactivity i.e. radioactive substances with various half-lives. Following the discovery of the emanations the volume of the research involving them and their disintegration products grew steeply. The identity of a number of these radioactive products was soon established. Radium emanation was soon used as a source of RaD (210Pb) to be applied as an 'indicator' (radiotracer) for lead in a study on the solubility of lead sulphide and lead chromate. Moreover, radium and its emanation were introduced into the medical practice. Inhaling radon and drinking radon-containing water became an accepted medicinal use (or misuse?) of that gas. Shortly after the turn of the century, the healing (?) action of natural springs (spas) was attributed to their radium emanation, i.e. radon. Bathing in radioactive spring water and drinking it became very popular. Even today, bathing in radon-containing water is still a common medical treatment in Jachymov, Czech Republic. (author)

  8. Prediction of radiation induced liver disease using artificial neural networks

    The objective of this study was to evaluate the efficiency of predicting radiation induced liver disease (RILD) with an artificial neural network (ANN) model. From August 2000 to November 2004, a total of 93 primary liver carcinoma (PLC) patients with single lesion and associated with hepatic cirrhosis of Child-Pugh grade A, were treated with hypofractionated three-dimensional conformal radiotherapy (3DCRT). Eight out of 93 patients were diagnosed RILD. Ninety-three patients were randomly divided into two subsets (training set and verification set). In model A, the ratio of patient numbers was 1:1 for training and verification set, and in model B, the ratio was 2:1. The areas under receiver-operating characteristic (ROC) curves were 0.8897 and 0.8831 for model A and B, respectively. Sensitivity, specificity, accuracy, positive prediction value (PPV) and negative prediction value (NPV) were 0.875 (7/8), 0.882 (75/85), 0.882 (82/93), 0.412 (7/17) and 0.987 (75/76) for model A, and 0.750 (6/8), 0.800 (68/85), 0.796 (74/93), 0.261 (6/23) and 0.971 (68/70) for model B. ANN was proved high accuracy for prediction of RILD. It could be used together with other models and dosimetric parameters to evaluate hepatic irradiation plans. (author)

  9. Medical imaging was boosted by the discovery of artificial radioactivity; L'imagerie medicale revelee par la radioactivite

    Demarthon, F.; Dupuy-Maury, F.; Donnars, O

    2002-08-01

    This article draws the history of medical imaging since the discovery of artificial radioactivity in 1934. The author reviews the PET (positron emission tomography) and MRI (magnetic resonance imaging) technologies and presents the recent progress in neuro-sciences that have been made possible by using these 2 technologies. Brain imaging has allowed to show: - the impact of emotions on logical mental processes and on mental performances, - the management of memory in the brain of talented quick reckoners, - the degeneration of neurons, and - the link between autism and the presence of structural and functional anomalies in the brain. (A.C.)

  10. Computational Catalysis Using the Artificial Force Induced Reaction Method.

    Sameera, W M C; Maeda, Satoshi; Morokuma, Keiji

    2016-04-19

    The artificial force induced reaction (AFIR) method in the global reaction route mapping (GRRM) strategy is an automatic approach to explore all important reaction paths of complex reactions. Most traditional methods in computational catalysis require guess reaction paths. On the other hand, the AFIR approach locates local minima (LMs) and transition states (TSs) of reaction paths without a guess, and therefore finds unanticipated as well as anticipated reaction paths. The AFIR method has been applied for multicomponent organic reactions, such as the aldol reaction, Passerini reaction, Biginelli reaction, and phase-transfer catalysis. In the presence of several reactants, many equilibrium structures are possible, leading to a number of reaction pathways. The AFIR method in the GRRM strategy determines all of the important equilibrium structures and subsequent reaction paths systematically. As the AFIR search is fully automatic, exhaustive trial-and-error and guess-and-check processes by the user can be eliminated. At the same time, the AFIR search is systematic, and therefore a more accurate and comprehensive description of the reaction mechanism can be determined. The AFIR method has been used for the study of full catalytic cycles and reaction steps in transition metal catalysis, such as cobalt-catalyzed hydroformylation and iron-catalyzed carbon-carbon bond formation reactions in aqueous media. Some AFIR applications have targeted the selectivity-determining step of transition-metal-catalyzed asymmetric reactions, including stereoselective water-tolerant lanthanide Lewis acid-catalyzed Mukaiyama aldol reactions. In terms of establishing the selectivity of a reaction, systematic sampling of the transition states is critical. In this direction, AFIR is very useful for performing a systematic and automatic determination of TSs. In the presence of a comprehensive description of the transition states, the selectivity of the reaction can be calculated more accurately. For relatively large molecular systems, the computational cost of AFIR searches can be reduced by using the ONIOM(QM:QM) or ONIOM(QM:MM) methods. In common practice, density functional theory (DFT) with a relatively small basis set is used for the high-level calculation, while a semiempirical approach or a force field description is used for the low-level calculation. After approximate LMs and TSs are determined, standard computational methods (e.g., DFT with a large basis set) are used for the full molecular system to determine the true LMs and TSs and to rationalize the reaction mechanism and selectivity of the catalytic reaction. The examples in this Account evidence that the AFIR method is a powerful approach for accurate prediction of the reaction mechanisms and selectivities of complex catalytic reactions. Therefore, the AFIR approach in the GRRM strategy is very useful for computational catalysis. PMID:27023677

  11. The induced radioactivity danger parameter for gamma radiation

    Dosimetric and practical aspects of the induced radioactivity danger parameter, as used for calculating the gamma radiation dose rate near to objects that have been exposed to high energy radiation, are examined. A simplified and more generally applicable method of calculation is proposed, based on energy balance in homogeneous media. The problems of applying this in practice are discussed, and it is shown that corrections are generally small enough to be neglected in many practical applications. Examples of calculations by previous and proposed methods are given. (author)

  12. Study of the behaviour of artificial radioactive aerosols. Applications to some problems of atmospheric circulation (1963)

    The aim of this work, consists in the examination of the behaviour of radioactive aerosols produced in the atmosphere by nuclear explosions, in order to deduce the most general laws governing atmospheric circulation and diffusion. After having given a general table of the radioactive aerosols present the authors consider the validity and the precision of the measurement methods and the concentration of the aerosols at ground level and in the upper atmosphere, as well as their deposition on the ground. The existence is thus demonstrated of a tropospheric equatorial barrier and of discontinuous and seasonal aspects of stratosphere-troposphere transfers. The role is shown of precipitations and dry auto-filtration in the lower atmosphere cleaning processes. This work makes it possible to describe the general behaviour of dust from the stratosphere, and to improve the total radioactive contamination of the globe. (author)

  13. Artificial radioactivity in the vicinity of St. Marianna University School of Medicine after the Chernobyl reactor accident

    Following the Chernobyl reactor accident on April 26, 1986, rain water and atomospheric dust were monitored for their possible contamination by artificial radionuclides on the roof of the building of our medical school from April 30 through June 8, 1986. Radiological monitoring was also performed on cabbages obtained from a nearby field, city water, cow's milk produced in Kanagawa Prefecture and human milk obtained from a volunteer living in Kawasaki. Our campus and the nearby area were exposed to 131I from May 2 through 22 by rainfall and from May 1 through 15 by atomospheric dust. In particular, rain water on May 4 and May 5 contained 7600 pCi (282 Bq)/l and 6000 pCi (222 Bq)/l, respectively. The cabbage specimen obtained on May 7 was contaminated by 131I with 808 pCi/kg wet weight, but another specimen obtained on June 6 was not contaminated by any detectable amounts of 131I. No radioactivity was detected in city water during the period monitored. Cow's milk and human milk contained, as a total of β-radioactivity, 1412 pCi (52 Bq)/l and 915 pCi (34 Bq)/l, respectively. However, parallel determinations on their potassium concentrations revealed that these radioactivities were due entirely to natural 40K. The degree of radiological contamination in and around our campus following the Chernobyl accident was mostly below the action levels above which the governments of several countries involving Japan would take preventive measures against possible radiation damages. Although 131I radioactivities contained in the rain water of the first week of May, 1986 significantly exceeded the action level for this radionuclide, their effects on human health were considered negligible and undetectable in the vicinity of our school. (author)

  14. The electrical charging of inactive aerosols in high ionised atmosphere, the electrical charging of artificial beta radioactive aerosols

    The electrical properties of aerosols greatly influence their transport and deposition in a containment. In a bipolar ionic atmosphere, a neutral electric charge on aerosols is commonly assumed. However, many studies report a different charge distribution in some situations, like highly ionised atmosphere or in the case of radioactive aerosols. Such situations could arise from a hypothetical accident in a nuclear power plant. Within the framework of safety studies which are carried out at IPSN, our aims were the study of electrical properties of aerosols in highly ionised atmosphere, and the study of artificial radioactive aerosols, in order to suggest experimental validation of available theories. For this purpose, we designed an experimental device that allows us to measure non-radioactive aerosol charge distribution under high gamma irradiation, up to 104 Gy/h. With our experimental device we also studied the properties of small ions in the medium. Our results show a variation of the charge distribution in highly ionised atmosphere. The charge increases with the dose of gamma ray. We have related this variation with the one of the small ions in the gases, according to theoretical prediction. However, the model overestimates slightly our experimental results. In the case of the radioactive aerosols, we have designed an original experimental device, which allows us to study the charge distribution of a 137Cs aerosol. Our results show that the electric charging of such aerosols is strongly dependent on evolution parameters in a containment. So, our results underline a great enhancement of self-charging of particles which are sampled in a confined medium. Our results are qualitatively in agreement with the theoretical model; nevertheless the latter underestimates appreciably the self-charging, owing to the fact that wall effects are not taken into account. (author)

  15. Effective dose equivalent to breast fed infants due to artificial and natural radioactivity

    After the Chernobyl accident, the Italian National Institute of Health (ISS), with the collaboration of the Epidemiological Unit of Latium District, started a research devoted to the study of the radioactive contamination of human milk in Latium. The motivation is three-fold, namely: to measure the contamination of a food product utilised for infants in order to assess the corresponding dose to breast-fed infants; to clarify any possible correlations between radioactive levels in human milk and those in the total body; to correlate the levels in human milk with those in the maternal diet

  16. Artificial Intelligence based Solver for Governing Model of Radioactivity Cooling, Self-gravitating Clouds and Clusters of Galaxies

    Junaid Ali Khan

    2013-06-01

    Full Text Available In this study, a reliable alternate platform is developed based on artificial neural network optimized with soft computing technique for a non-linear singular system that can model complex physical phenomenas of the nature like radioactivity cooling, self-gravitating clouds and clusters of galaxies. The trial solution is mathematically represented by feed-forward neural network. A cost function is defined in an unsupervised manner that is optimized by a probabilistic meta-heuristic global search technique based on annealing in metallurgy. The results of the designed scheme are evaluated by comparing with the desired response of the system. The applicability, stability and reliability of the proposed method is validated by Monte Carlo simulations.

  17. Levels of natural and artificial radioactivity in sediments in the Eastern Black Sea of Turkey

    Sediments samples collected from the Eastern Black Sea in 1993 from 15 sampling stations of different depths have been analyzed. Natural and artificial radionuclide activity levels in offshore sediment samples from the Eastern Black Sea in Turkey are reported about seven years after the Chernobyl accident. The purpose of this paper is to follow up the earlier study and present results for the distributions of radionuclides in sediments of the Black Sea. (author). 14 refs., 2 figs., 2 tabs

  18. Daily measurements of natural and artificial atmospheric radioactivity in 1959 (1960)

    Daily numerical results of measures concerning β activity of the air, either from natural, owing to thoron, or from artificial, owing to active aerosols origin, will be found in this statement. The all results are expressed in μμCurie/m3 of air. Proceedings of measure and technic of standardization, which were the matter of anterior papers, have not been discussed once more here. (author)

  19. A comparison of artificial saliva and pilocarpine in radiation-induced xerostomia

    Twenty patients with radiation-induced xerostomia were entered into a prospective randomized crossover study comparing a mucin-based artificial saliva (Saliva Orthana) and a mouthwash containing pilocarpine (5 mg three times a day). Overall the patients found that the pilocarpine mouthwash was more effective than the artificial saliva in relieving their symptoms (p = 0.04), and 47 per cent of the patients wanted to continue with this treatment after the study had finished. (author)

  20. Artificial radioactivity layers in the Devon Island ice cap, Northwest Territories

    Bomb-produced radioactive fall-out layers are evident in the firn at the top of the Devon Island ice cap and also lower down in a zone where accumulation is in the form of re-frozen melt-water. This allows 1963-1974 snow accumulation (positive balance) gradients for the same period to be determined on sub-polar ice caps in Canada. (author)

  1. NATURAL AND ARTIFICIAL RADIOACTIVITY IN BULGARIAN SOILS ALONG THE DANUBE RIVER

    I YORDANOVA

    2005-07-01

    Full Text Available Data from gamma-spectrometry analyses of soils and sediments samples taken along the Danube river is presented in the paper. Results about the content of natural and artifi cial radionuclides like Sr-90 and Cs-137 are discussed. The region around the Kozloduj NPP including its exclusion zone is investigated in more details. Data from the last years is compared with such from former investigations of similar samples from the region. The soil is a natural depot and initial reservoir for spreading of all man-made radionuclides and natural radioactivity. The man-made isotopes with the longest half-life time, like Sr-90 and Cs-137 are mainly investigated. Because of their feature to be bioelements, that is to include themselves in human’s metabolism, they are especially dangerous when their concentrations in the nutritious chain increase. That is why the investigation of these nuclides together with the natural once like uranium, thorium and radium started in 1978 with annual determination of their concentrations in soils collected from the region of “Kozloduj” NPP and some places along the Danube river potentially exposed to radioactive contamination. The aim was to make a picture of the radioecological status of the soils along the Danube river. The period after 1986 is concerned as the accident in Chernobyl’s NPP changed basically the radioactive situation in the country.

  2. Natural and artificial radioactivity distribution in soil of Fars Province, Iran.

    Faghihi, R; Mehdizadeh, S; Sina, S

    2011-04-01

    Fars province is a large populated large province located in the southwest of Iran. This work presents a study of natural and radioactivity levels in soil samples of this province. For this purpose, 126 samples were gathered from different regions of the province and analysed by gamma spectroscopy to quantify radioactivity concentrations of radionuclides using a high-purity germanium detector and spectroscopy system. The results of this investigation show the average concentrations of 271 28 Bq kg(-1), 6.37 0.5 Bq kg(-1), 14.9 0.9 Bq kg(-1) and 26.3 1.9 Bq kg(-1) for (40)K, (137)Cs, (232)Th and (238)U in soil, respectively. Finally, baseline maps were established for the concentrations of each of the radionuclides in different regions. The absorbed dose rate and the annual effective dose (AED) were also calculated for the radionuclides according to the guidelines of UNSCEAR 2000. The average AED from the radioactivity content of soil in this province was found to be 39.9 1.8 ?Sv. PMID:21081518

  3. Evaluation of induced radioactivity in 10 MeV-electron irradiated spices, (1)

    Black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electrons from a linear accelerator to a dose of 100 kGy and radioactivity was measured in order to estimate induced radioactivity in the irradiated foods. Induced radioactivity could not be detected significantly by γ-ray spectrometry in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list of photonuclear reactions which could produce radioactivity below 10 MeV. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H50 according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from 40K contained in the samples. (author)

  4. Human Health Impact of Natural and Artificial Radioactivity Levels in the Sediments and Fish of Bonny Estuary, Niger Delta, Nigeria

    Bolaji B. Babatunde

    2015-11-01

    Full Text Available There is widespread contamination of the environment of the Niger Delta, which may include enhanced background levels of naturally occurring radioactive materials (NORM due to oil production and rapid urbanization activities. Sediments and seafood from the Bonny estuary, Niger Delta, were collected for the purpose of determining baseline data on artificial and natural radioactivity and estimation of effective doses for the public due to ingestion of seafood from the study area. The highest and lowest activity concentrations were reported for 40K and 137Cs in both sediments and fish samples of the Bonny estuary. There was some evidence of spatial variability in the 40K and 137Cs data, with the latter being the likely result of dredging. Other radionuclides were not significantly different between sites impacted by industrial activities or not. Activity of radionuclides measured in the sediments of the study area were higher than reported elsewhere in the Niger Delta and Nigeria and higher than reported global averages by UNSCEAR. The total highest activity concentration in all fish species of gamma emitting radionuclides was observed for 40K, followed by 238U, 232Th and 226Ra, respectively, while 137Cs had the lowest activity concentration. However, 210Po activities were the most important in terms of dose contribution. Consumption of molluscs at typical rates could result in doses exceeding 1 mSv·y−1. Although this baseline data may not be conclusive on prevailing trends in radioactivity in the study area, higher consumption rates of the species studied may have public health consequences due to effects of low dose ionising radiation.

  5. Low-induced radioactivity ultrahigh vacuum system using aluminum alloy

    In the High Energy Physics Laboratory in Tsukuba, the development of an ultrahigh vacuum system made of aluminum was successfully achieved for the first time in the world, and at present, the TRISTAN ring is under construction. The discovery and verification that aluminum and its alloys are very advantageous for reducing radioactivity exposure became the opportunity to begin, and the research has been advanced, as the result, also the rate of released gas was able to be improved as compared with conventional stainless steel. The application to nuclear fusion equipment, semiconductor production facility such as molecular beam epitaxy and analysis equipment as well as accelerators is promoted. The induced radioactivity of five kinds of metallic sheets was compared, and the change of the material for the vacuum system of particle accelerators to aluminum alloy was planned. The newly developed ultrahigh vacuum system made of aluminum alloys is described, and its application to the particle accelerator TRISTAN is explained. In the application to nuclear fusion experimental apparatus, the use of Al-Li-Mg alloy may resolve the problems. The findings obtained at the Laboratory are shown. (Kako, I.)

  6. Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy

    Radioactive iodine (131I) is accumulated in the thyroid tissue and plays an important role in the treatment of differentiated papillary and follicular cancers after thyroidectomy. Simultaneously, 131I is concentrated in the salivary glands and secreted into the saliva. Dose-related damage to the salivary parenchyma results from the 131I irradiation. Salivary gland swelling and pain, usually involving the parotid, can be seen. The symptoms may develop immediately after a therapeutic dose of 131I and/or months later and progress in intensity with time. In conjunction with the radiation sialadenitis, secondary complications reported include xerostomia, taste alterations, infection, increases in caries, facial nerve involvement, candidiasis, and neoplasia. Prevention of 131I sialadenitis may involve the use of sialogogic agents to hasten the transit time of the radioactive iodine through the salivary glands. However, studies are not available to delineate the efficacy of this approach. Treatment of the varied complications that may develop encompass numerous approaches and include gland massage, sialogogic agents, duct probing, antibiotics, mouthwashes, good oral hygiene, and adequate hydration. Recently interventional sialoendoscopy has been introduced an effective tool for the management of patients with 131I-induced sialadenitis that is unresponsive to medical treatment.

  7. Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy

    Jeong, Shin Young; Lee, Jaetae [Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2010-06-15

    Radioactive iodine ({sup 131}I) is accumulated in the thyroid tissue and plays an important role in the treatment of differentiated papillary and follicular cancers after thyroidectomy. Simultaneously, {sup 131}I is concentrated in the salivary glands and secreted into the saliva. Dose-related damage to the salivary parenchyma results from the {sup 131}I irradiation. Salivary gland swelling and pain, usually involving the parotid, can be seen. The symptoms may develop immediately after a therapeutic dose of {sup 131}I and/or months later and progress in intensity with time. In conjunction with the radiation sialadenitis, secondary complications reported include xerostomia, taste alterations, infection, increases in caries, facial nerve involvement, candidiasis, and neoplasia. Prevention of {sup 131}I sialadenitis may involve the use of sialogogic agents to hasten the transit time of the radioactive iodine through the salivary glands. However, studies are not available to delineate the efficacy of this approach. Treatment of the varied complications that may develop encompass numerous approaches and include gland massage, sialogogic agents, duct probing, antibiotics, mouthwashes, good oral hygiene, and adequate hydration. Recently interventional sialoendoscopy has been introduced an effective tool for the management of patients with {sup 131}I-induced sialadenitis that is unresponsive to medical treatment.

  8. Muon-induced production of radioactive isotopes in scintillation detectors

    Hagner, T; Heisinger, B; Oberauer, L; Schnert, S; Von Feilitzsch, F; Nolte, E

    2000-01-01

    The production of radioactive isotopes in scintillation detectors by muons and their secondary shower particles has been studied experimentally at the SPS muon beam at CERN. This paper shows the results obtained in cross-section measurements on liquid scintillator targets, especially on /sup 12/C which is the most relevant target in these organic materials. Their energy dependence has been deduced from the cross-sections determined at two muon energies 100 and 190 GeV. Based on the measured cross-sections the muon-induced background rates for the forthcoming solar neutrino experiments BOREXINO and KAMLAND have been calculated for different energy regions that are relevant for solar neutrino physics. (23 refs).

  9. Transport and dispersion of artificial radioactivity in the Arctic Ocean - Model studies and observations -

    The Arctic Ocean and the adjacent shelf regions are subject to growing concern because of increasing environmental problems. The most crucial problem arises probably from the dumping of nuclear waste in the Barents and the Kara Sea. But also the great Siberian rivers Ob and Yenisei which drain huge land areas and industrial zones may contribute to the input of pollutants into the Arctic environment. First results of a joint project are described which combines numerical model studies and experimental field work in order to investigate the potential pathways and dispersion of radioactive contaminants in the Arctic Ocean. (author)

  10. Exchange of radioactive phosphorus 32P between the components of an artificial plant community

    In artificial plant communities (wooden cases with soil) the following plants were grown together for one year: case No. 1: Betula verrucosa Ehrh. (2 specimens) and Carex pilosa Scop.; cases No. 2 and 3: Alnus incana (L.) Mnch., Fraxinus excelsior L., Padus avium Mill., Aegopodium podagraria L., Eupatorium cannabinum L. and others. Into the stalks or stems of one to three plants of every case 32P was introduced. After 3 months all the plants in every case contained radiactive phosphorus. There were great differences in 32P concentration (up to ten-fold) between plants grown in the same case. The concentration of 32P in plants into which it had not been introduced was of the range of 0.1%. (author)

  11. Studies of artificial radioactivity in the coastal environment of northern Scotland: a review

    This review brings measurements that have been made over the last 10-15 years of the concentrations of a number of artificial radionuclides in various media in the northern-Scottish coastal environment. The radionuclides include 60Co, 90Sr, 136Cs, 137Cs, 238Pu, 239,240Pu, and 241Am. The media include nearshore and offshore seawater, beach sand and sediments, seaweeds, winkles, spume, deposits on rocks and soils, sheep faeces, and atmospheric deposition. The various radionuclide sources that contribute to the study area are described. Some transfer mechanisms that operate between different media for different radionuclides are discussed, and the radiological significance of the observed radionuclide concentrations is briefly described. (Author)

  12. Natural and artificial enhanced radioactivity in the Lake Kerkini and the River Strymon (Greece)

    Measurements of naturally occurring and artificially enhanced radionuclides in the Lake Kerkini at Serres Region, Northern Greece, were made in estimating cumulative inputs originating from Bulgaria and transferred by the River Strymon passing through the lake. Radium-226 as well as Radium-228 ranged between 60 and 80 Bq.kg-1 dry weight in the reservoir sediments. Potassium-40 ranged between 560 and 720 Bq.kg-1 dry weight. Cesium-137 ranged between 60 and 140 Bq.kg-1 dry weight, due to the fallout from the Chernobyl accident. The natural radionuclides were uniformly distributed in the basin of the Lake Kerkini, while 137Cs was differentially distributed because of recycling effects caused by the aquatic plants and organisms in biota and the movement of brought material from high elevations surrounding the lake basin. (Author) 2 tabs., 3 figs., 9 refs

  13. Artificial radioactivity in fuel peat and peat ash in Finland after the Chernobyl accident

    The accident at the Chernobyl nuclear power plant in April 1986 caused very uneven deposition of radionuclides in Finland. The deposited radionuclides were found in relatively high concentrations in fuel peat and especially in peat ash because a thin surface layer of peat-production bogs was extracted as fuel peat soon after the fallout occurred. Concentrations of artificial radionuclides in fuel peat and peat ash were measured at six peat-fired power plants in Finland throughout the heating season 1986-87. Concentrations of 137Cs in composite peat samples varied between 30 and 3600 Bq kg-1 dry weight and in ash samples between 600 and 68,000 Bq kg-1. High concentrations in peat ash caused some restrictions to the utilization of peat ash for various purposes

  14. Evaluation of artificial radioactivity of the North Western Mediterranean Sea and evaluation of the sanitary consequences

    Calmet, D.; Daburon, M.L.; Willemot, J.M. (Commissariat a l' Energie Atomique, Institut de Protection et de Surete Nucleaire, 92 - Fontenay-aux-Roses (France))

    1985-01-01

    The results of radiological measurements of the North Western Mediterranean observation network outline the level of artificial radionuclides coming from industrial seewages, WRu and from atmospheric fall out, TXCs and sup(239 + 240)Pu measured on 3 differents types of bioindicators: Mytilus sp., Posidonia oceanica (L.) Del. and demersal fishes as Solea sp., Anguilla anguilla L., Conger conger L. Mytilus sp. is quite a perfect bioindicator of radionuclides contamination but must be linked with fishes sampling which muscles concentrate Cesium at higher level. The sanitary consequences for the waterside population involved by molluscs and fishes ingestion contamined by these 3 radionuclides lead to a fraction (10 V) of the annual dose limit recommanded by the ICRP 26.

  15. Evaluation of artificial radioactivity of the north Western mediterranean sea and evaluation of the sanitary consequences

    The results of radiological measurements of the north west mediterranean observation network outline the level of artificial radionuclides coming from industrial seewages, 106Ru and from atmospheric fall out, 137Cs and sup(239+240)Pu measured on 3 differents types of bioindicators: Mytilus sp., Posidonia oceanica (L.) Del. and demersal fishes as Solea sp., Anguilla anguilla L., Conger conger L. Mytilus sp. is quite a perfect bioindicator of radionuclides contamination but must be linked with fishes sampling which muscles concentrate Cesium at higher level. The sanitary consequences for the waterside population involved by molluscs and fishes ingestion contamined by these 3 radionuclides lead to a fraction (10-5) of the annual dose limit recommanded by the ICRP 26

  16. Using radioactivity

    The leaflet discusses the following: radioactivity; radioisotopes; uses of ionising radiations; radioactivity from (a) naturally occurring radioactive elements, and (b) artificially produced radioisotopes; uses of radioactivity in medicine, (a) clinical diagnostic, (b) therapeutic (c) sterilization of medical equipment and materials; environmental uses as tracers; industrial applications, e.g. tracers and radiography; ensuring safety. (U.K.)

  17. Natural and artificial radioactivity in surface waters of the Ebro river basin (Northeast Spain)

    A radiological characterisation of surface waters of the Ebro river basin was carried out during November 1994. For this purpose, 75 water samples were collected from points distributed throughout the Ebro river basin. Analysis included gross alpha and gross beta activities, relevant natural radionuclides (40K, 226Ra, 234,238U -uranium total-) and several artificial radionuclides (3H, 90Sr and radiocaesium). Mean gross alpha and gross beta activities in surface waters of the river's main course were 0.095±0.004 and 0.213±0.012 Bq l-1, respectively. Mean activities of 40K, 226Ra and uranium (total) were 0.132±0.009, 0.0282±0.0008 and 0.053±0.006 Bq l-1, respectively. Regarding artificial radionuclides, the mean 90Sr activity was 6.6±0.3 mBq l-1, 3H was detected in 8% of the samples, and radiocaesium was not detected in any sample. It is estimated that almost 100% of gross alpha and 97% of gross beta activities of surface waters in the Ebro river came from natural sources. Furthermore, results showed that the geological setting, large cities, agricultural areas and dams strongly influence the occurrence of natural radionuclides. Contamination from nuclear power plants located along the river was not detected. Finally, we estimated that the annual dose equivalent due to the hypothetical ingestion of Ebro river waters was 7.59 μSv y-1, which represented only 0.3% of the average annual effective dose attributable to natural background radiation in the area

  18. Artificial stone dust-induced functional and inflammatory abnormalities in exposed workers monitored quantitatively by biometrics

    Noa Ophir

    2016-03-01

    Full Text Available The manufacture of kitchen and bath countertops in Israel is based mainly on artificial stone that contains 93% silica as natural quartz, and ∼3500 workers are involved in cutting and processing it. Artificial stone produces high concentrations of silica dust. Exposure to crystalline silica may cause silicosis, an irreversible lung disease. Our aim was to screen exposed workers by quantitative biometric monitoring of functional and inflammatory parameters. 68 exposed artificial stone workers were compared to 48 nonexposed individuals (controls. Exposed workers filled in questionnaires, and all participants underwent pulmonary function tests and induced sputum analyses. Silica was quantitated by a Niton XL3 X-ray fluorescence spectrometer. Pulmonary function test results of exposed workers were significantly lower and induced sputa showed significantly higher neutrophilic inflammation compared to controls; both processes were slowed down by the use of protective measures in the workplace. Particle size distribution in induced sputum samples of exposed workers was similar to that of artificial stone dust, which contained aluminium, zirconium and titanium in addition to silica. In conclusion, the quantitation of biometric parameters is useful for monitoring workers exposed to artificial stone in order to avoid deterioration over time.

  19. Destabilization of artificial biomembrane induced by the penetration of tryptophan

    The effect of tryptophan on the membrane stability was studied by using three artificial biological membranes including liposome, Langmuir monolayer and solid supported bilayer lipid membrane (s-BLM) as models. All the results indicate that the penetration of tryptophan can destabilize different artificial biological membranes. The diameter of liposome and the leakage of calcein from liposome increased with the increase of tryptophan concentration because the penetration of tryptophan was beneficial for dehydrating the polar head groups of lipids and the formation of fusion intermediates. π-A isotherms of lecithin on the subphase of tryptophan solution further confirm that tryptophan can penetrate into lipid monolayer and reduce the stability of lipid monolayer. When the concentration of tryptophan increased from 0 to 2 x 10-3 mol L-1, the limiting molecular area of lecithin increased from 110.5 to 138.5 A2, but the collapse pressure of the monolayer decreased from 47.6 to 42.3 mN m-1, indicating the destabilization of lipid monolayer caused by the penetration of tryptophan. The resistance spectra of s-BLM demonstrate that the existence of tryptophan leads to the formation of some defects in s-BLM and the destabilization of s-BLM. The values of electron-transfer resistance and double layer capacitance respectively decreased from 5.765 x 106 Ω and 3.573 x 10-8 F to 1.391 x 106 Ω and 3.340 x 10-8 F when the concentration of tryptophan increased from 0 to 2 x 10-3 mol L-1. Correspondingly, the breakdown voltage of s-BLM decreased from 2.51 to 1.72 V.

  20. Destabilization of artificial biomembrane induced by the penetration of tryptophan

    Chen Liuhua [Department of Chemistry, Tongji University, Shanghai 200092 (China); Gan Lihua, E-mail: ganlh@tongji.edu.cn [Department of Chemistry, Tongji University, Shanghai 200092 (China); Liu Mingxian; Fan Rong; Xu Zijie; Hao Zhixian; Chen Longwu [Department of Chemistry, Tongji University, Shanghai 200092 (China)

    2011-03-15

    The effect of tryptophan on the membrane stability was studied by using three artificial biological membranes including liposome, Langmuir monolayer and solid supported bilayer lipid membrane (s-BLM) as models. All the results indicate that the penetration of tryptophan can destabilize different artificial biological membranes. The diameter of liposome and the leakage of calcein from liposome increased with the increase of tryptophan concentration because the penetration of tryptophan was beneficial for dehydrating the polar head groups of lipids and the formation of fusion intermediates. {pi}-A isotherms of lecithin on the subphase of tryptophan solution further confirm that tryptophan can penetrate into lipid monolayer and reduce the stability of lipid monolayer. When the concentration of tryptophan increased from 0 to 2 x 10{sup -3} mol L{sup -1}, the limiting molecular area of lecithin increased from 110.5 to 138.5 A{sup 2}, but the collapse pressure of the monolayer decreased from 47.6 to 42.3 mN m{sup -1}, indicating the destabilization of lipid monolayer caused by the penetration of tryptophan. The resistance spectra of s-BLM demonstrate that the existence of tryptophan leads to the formation of some defects in s-BLM and the destabilization of s-BLM. The values of electron-transfer resistance and double layer capacitance respectively decreased from 5.765 x 10{sup 6} {Omega} and 3.573 x 10{sup -8} F to 1.391 x 10{sup 6} {Omega} and 3.340 x 10{sup -8} F when the concentration of tryptophan increased from 0 to 2 x 10{sup -3} mol L{sup -1}. Correspondingly, the breakdown voltage of s-BLM decreased from 2.51 to 1.72 V.

  1. Use of artificial barriers in a site for surface storage of radioactive waste

    The objective is the on site study of the influence of an injection screen on the flow in a water table of a porous medium, in order to improve the safety of a surface radioactive waste storage site. A hydrodispersive study has provided information for the definition of the role of the screen: the transfer times of the pollutant in the water table are increased by a factor of 2 and, in comparison, the concentration are clearly reduced by a factor of 10. The implantation of an injection screen in the ground should result in an improvement in the restrictive quality of the barrier and the contamination of an aquifer should be slower without interruption to the flow

  2. Natural and artificial radioactivity in milk and dairy products for human consumption (1971-2003)

    Between 1971 and 2003, radioactivity analyses were performed in several dairy products (fresh milk, milk in powder, evaporated milk and in mixed-cereal flours) as part of the program of national environmental radiological surveillance developed by the Department of Environment Control of the Peruvian Nuclear Energy Institute. Analytical assays were performed to evaluate Cs-137, Cs-134, I-131, K-40, Sr-90 (by gamma spectroscopy) and gross beta activity (by beta counting). The obtained values do not represent radiosanitary risk for the population and confirm the presence of K-40 as the main radionuclide in this type of samples. The application of IAEA dosimetric factors allowed calculating intake doses from dairy products in a much lower level than the limits established by international regulation bodies. (author)

  3. Artificial and natural radioactivity measurements in the vicinity of Ghana nuclear research reactor (GHARR-1)

    Radioactivity concentrations of 226Ra, 232Th, 40K and 137Cs in soil and water samples around the Ghana Research Reactor-1 (GHARR-1) and the immediate surroundings have been investigated using gamma spectrometry. The primary aim of this study was to establish baseline radioactivity levels in the environs of GHARR-1. The average activity concentration in soil for 226Ra, 232Th, 40K and 137Cs were 19.8 Bqkg-1, 40.4 Bqkg-1, 95.3 Bqkg-1 and 1.5 Bqkg-1 respectively. For the water samples the average activity concentration of 226Ra was 2.15 Bql-1, 232Th was 0.61 Bql-1, 40K was 10.75Bql-1 and 137Cs was 0.47 Bql-1. The 226Ra and 232Th concentrations compare quite well with world averages, whilst the 40K concentration was lower than the world average. The activity concentrations of 137Cs observed in the samples are within the range of background. concentrations. The estimated average annual effective dose from external exposure to soil and ingestion of water samples was calculated to be 0.64 mSv. The estimated outdoor external gamma dose rate measured in air ranged from 10-430 nGyh-1 with an average value of 41 nGyh-1 which is lower than the worldwide average value of 60 nGyh-1. In the case of the water samples, the average annual effective value was higher than the WHO guideline value of 0.1 mSvy-1 (author)

  4. Study on natural and artificial radioactivity of sea water, algae, fish, sea organisms and bottom sediments for the period 1965-1974

    Studies on natural and artificial radioactivity of some fish species, algae, mussels, etc., inhibiting Varna seacoast were carried out in 1965-1974. The samples were radiochemically investigated for total ?-activity, contents of potassium 40, uranium natural, radium 226, strontium 90, and cesium 137. A total of 602 samples are investigated. The results obtained from studying sea water show highest concentration in the village Byala - up to 69,00.10-9 Ci/l, and lowest - in the village of Shabla - up to 32,00.10-9 Ci/l. Radioactivity of some fish varies from 7,10 up to 67,50 pCi (per kg fresh product for strontium 90), and from 14,3 up to 63,50 pCi (per kg fresh product for cesium 137). It is established that scad fish contains the highest radioactivity. Data show that radioactivity in all cases was within the maximum permissible activity level. (author)

  5. Application of naturally occurring isotopes and artificial radioactive tracer for monitoring water flooding in oil field

    Water flooding is an important operation to enhance oil recovery. Water is injected in the oil formation under high pressure through an injection well. Movement of the injected water is needed to be traced to test the performance of water flood, investigate unexpected anomalies in flow and verify suspected geological barriers or flow channels, etc. In the present study environmental isotopes and artificial radiotracer (tritium) were used at Fimkassar Oil Field of Oil and Gas Development Company Limited (OGDCL) where water flooding was started in March 1996 in Sakessar formation to maintain its pressure and enhance the oil recovery. Environmental isotopes: /sup 18/O, /sup 2/H and /sup 3/H, and chloride contents were used to determine the breakthrough/transit time and contribution of fresh injected water. Water samples were collected from the injection well, production well and some other fields for reference indices of Sakessar Formation during June 1998 to August 1999. These samples were analyzed for the /sup 18/O, /sup 2/H and /sup 3/H, and chloride contents. Results show that the water of production well is mixture of fresh water and formation water. The fresh water contribution varied from 67% to 80%, while remaining component was the old recharged formation water. This percentage did not change significantly from the time of break-through till the last sampling which indicates good mixing in the reservoir and absence of any quick channel. The initial breakthrough time was 27 months as the fresh water contributed significantly in the first appearance of water in the production well in June 1998. Tritium tracer, which was injected in November 1998, appeared in the production well after 8 months. It show that breakthrough time decreased with the passage of time. /sup 14/C of inorganic carbon in the water in Chorgali and Sakessar Formations was also analyzed which indicates that the water is at least few thousand years old. (author)

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

    Full text: The Shagan river is the only surface waterway on the Semipalatinsk Nuclear Test Site territory. It flows along the eastern boundary of the SNTS and is a left-bank tributary of the Irtysh river. The length of the Shagan riverbed is 275 km with an average slope 0.003, which changes considerably from one part of the riverbed to the other. Within the Balapan testing ground the length of the riverbed is about 50 km, and the slope angle is, on average, 0.002. The watershed area of the left-bank part of the testing ground, where testing wells are located, is about 900 km2. In 2006 during radio-ecological investigations of the SNTS aquatic environment, scientists determined contamination of the Shagan river with radioactive products of nuclear explosions. The main radioactive pollutant is tritium. Maximal tritium concentration in the river waters (40*104 Bq/l) was registered 4.7 km away from the Atomic lake at levels of more than 50 times higher than the maximal permissible level for drinking water. As the distance from the Atomic lake increases, tritium concentration in the Shagan waters considerably decreases, and in the place of its confluence with the Irtysh rivertritium concentration in water becomes 10 Bq/l, which is equal to MPL (maximal permissible level) used for equipment. A complex of scientific investigations including hydrogeological, hydrological and geophysical investigation showed that tritium contamination of the Shagan waters is caused by the discharge of contaminated ground waters from the testing ground Balapan. In 2007 additional investigations of the river ecosystem showed that surface waters of the river in addition to tritium contained 90Sr, and bottom sedimentations were contaminated with 60Co, 152Eu, 154Eu and 137Cs. It should be noted that concentration of 90Sr in water reaches the level comparable with intervention level established by NRB-99 (Radiation Safety Norms) for water and food intake. By the character of tritium and 90Sr 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 90Sr has not been studied yet. To determine the reasons for noticeable increase of the 90Sr concentration in water and the ways of its proliferation into the river, additional investigations are necessary. Possible mechanisms for 90Sr proliferation into the river may be its inflow with ground waters, plane washing off, washing out of 90Sr 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*103 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

  7. Radioactivity

    This pedagogical document presents the origin, effects and uses of radioactivity: where does radioactivity comes from, effects on the body, measurement, protection against radiations, uses in the medical field, in the electric power industry, in the food (ionization, radio-mutagenesis, irradiations) and other industries (radiography, gauges, detectors, irradiations, tracers), and in research activities (dating, preservation of cultural objects). The document ends with some examples of irradiation levels (examples of natural radioactivity, distribution of the various sources of exposure in France). (J.S.)

  8. Disturbances of immunological homeostasis induced by radioactive iodine agents

    (CBAxC57B1/6)F1 mice were injected with 125I and 131I-sodium iodide at a dose of 5.74x104 Bq/g. For a long time after such treatment the animals manifested an increased level of spleen cells humoral immune response to a foreign antigen (sheep erythrocytes). The autoreactivity of spleen and lymph node lymphocytes to autologous erythrocytes was also elevated. At the same time the selective migration of 51Cr-labeled spleen lymphocytes to the peripheral lymphoid organs was suppressed. The use of a model system of adoptive cell transfer revealed an increase in the functional activity of cells suppressing a humoral response in mice treated with radiopharmaceuticals. The most pronounced disturbances of immunological reactivity in mice took place 6 mos. after the beginning of the experiment. The results obtained indicated that mechanisms of immune response regulation played a certain role in disturbances of immunological homeostasis induced by radioactive iodine agents

  9. Estimation of absorbed gamma dose in air due to natural and artificial radioactivity of soil. Resume of Ph.D thesis

    This is an extended abstract of the Ph. D. thesis devoted to the measurements of air absorbed gamma doses due to natural and artificial radioactivity in soil. It contains a summary of the four chapters of the thesis. The first chapter presents problems related to the measurement of natural and artificial radioactivity coming from soil contamination due to nuclear explosions or nuclear accidents. The natural and artificial radionuclides which usually contaminate the soil are reviewed. The chapter two presents the original contribution of the author in the field of the methods of soil sampling and NaI(Tl) gamma spectrometry analysis of radioactive samples. Also the results of the measurements carried out in 10 counties in Romania are here reported. The natural radionuclides measured were Ra-226, Th-232, and K-40, while the artificial radionuclides were Cs-137 and Cs-134. In the third chapter the radioactivity levels are reported as absorbed air gamma doses due to presence of 137 Cs and 134 Cs in soil. Also here the effective dose equivalents estimated for the population of the 10 counties are presented. In the concluding chapter four a discussion is given concerning the dose levels measured following the Chernobyl nuclear accident as function of time elapsed from the accident and of depth of soil sampling and of soil type. It is shown that the dose levels which affected the population in the studied zones are within the values of radioprotection standards in Romania. These data were used as input to solve the problem of the biological effects of low doses on the population health. (M.I.C.). 7 Figs., 10 Tabs., 73 Refs

  10. Designing a program to assess potential induced radioactivity in electron beam sterilization of medical devices

    ISO 11137-1:2006 requires that the potential for induced radioactivity be evaluated for medical devices irradiated with electrons with energy more than 10 MeV. For a manufacturing operation where new devices are being developed, a practical program for making such an evaluation needs to be engrained in the process. A program was developed such that the induced radioactivity evaluation is imbedded in the development of the irradiation process. - Highlights: • A program is described to evaluate induced radioactivity in electron beam. • The program entails evaluation of design prior to manufacturing. • Radiation measurement is done immediately following irradiation. • The instrument has adequate sensitivity for this purpose

  11. Observation of the effects of artificially released long half-life radionuclides on the global radioactive contamination background in the Atlantic and its adjoining seas

    In the behaviors of artificial and natural radionuclides in ocean, there is similarity. In the surface seawater in northern Atlantic Ocean, the seasonal variation in the concentration of falling strontium-90 was established, and its empirical formula was given. The review of the measured results of strontium-90, cesium-137 and -134 in North Sea and the former two in southern Baltic Sea indicated that the radioactive contamination in North Sea due to the release of the radioactive materials, which are not regulated in London Convention concerning the sea dumping of wastes, is far higher than the peak in 1963. Also by the exchange of water masses, radioactive materials entered Baltic Sea. The inflow of cesium-137 from North Sea into Baltic Sea in 1979 was over 10 times as much as that from rivers. In the sea area adjoining the strait, however, cesium-137 of high concentration was not observed. (J.P.N.)

  12. A decade of assessment of the natural and artificial radioactivity in feedstuff and food commodities imported and exported by Brazil

    Full text: Natural and artificial radionuclides in feedstuff with concentration levels surpassing the brazilian (CNEN-NN 3.05, January 2005) and international (IAEA 115 Safety Series, 1996 and Codex Alimentarius, 2006) limits are harmless to the human health and an effective control is needed in order to only allow consumption of products presenting radiation levels below limits. Since 1988, after the Chernobyl accident, the Environmental Radiometric Laboratory at the Nuclear and Energy Research Institute, IPEN-CNEN/SP (Instituto de Pesquisas Energeticas e Nucleares), performs, on a regular basis, analysis of potassium-40, cesium-134 and cesium-137 concentrations in feedstuff and food commodities imported and exported by Brazil. The present work covers mostly a decade of results, from 1996 to 2007, assessed from the measurements of almost 2600 samples. The imported Belgium and the exported ones are originated from 14 Brazilian States and 111 regions. Nearly 90 different kinds of feedstuff and food commodities were measured, including condensed milk, milk powder, soy beans, sugar, raw coffee beans, etc. All samples were analyzed by high resolution gamma-spectrometry and the results, compared with brazilian and international limits, released as a technical report. The radioactivity present in all analyzed products was within the international limits, allowing to conclude that consumption of such goods offers no health risk derived from radiation. Potential relationships between the type and the origin of the products exported and imported by Brazil and the radionuclides concentrations are also approached. Finally, all results will contribute to the establishment of a radiometric database for the radionuclides concentrations in the feedstuff and food commodities produced in Brazil. (author)

  13. Designing a program to assess potential induced radioactivity in electron beam sterilization of medical devices

    Smith, Mark; Logar, John; Vrain, Olivier

    2014-12-01

    ISO 11137-1:2006 requires that the potential for induced radioactivity be evaluated for medical devices irradiated with electrons with energy more than 10 MeV. For a manufacturing operation where new devices are being developed, a practical program for making such an evaluation needs to be engrained in the process. A program was developed such that the induced radioactivity evaluation is imbedded in the development of the irradiation process.

  14. Earthquake-induced landslide-susceptibility mapping using an artificial neural network

    Lee, S.; Evangelista, D. G.

    2006-01-01

    The purpose of this study was to apply and verify landslide-susceptibility analysis techniques using an artificial neural network and a Geographic Information System (GIS) applied to Baguio City, Philippines. The 16 July 1990 earthquake-induced landslides were studied. Landslide locations were identified from interpretation of aerial photographs and field survey, and a spatial database was constructed from topographic maps, geology, land cover and terrain mapping units. Factors that influence...

  15. Electromagnetically Induced Transparency Using a Artificial Molecule in Circuit Quantum Electrodynamics

    Hai-Chao Li; Guo-Qin Ge

    2013-01-01

    Electromagnetically induced transparency (EIT) having wide applications in quantum optics and nonlinear optics is explored ordinarily in various atomic systems. In this paper we present a theoretical study of EIT using supercon- ducting circuit with a V-type artificial molecule constructed by two Josephson charge qubits coupled each other through a large capacitor. In our theoretical model we make a steady state approximation and obtain the analytical expressions of the complex susceptibilit...

  16. Reevaluation of induced radioactivity in 10MeV electron-irradiated pepper for public acceptance

    Furuta, M.; Katayama, T.; Ito, N.; Mizohata, A.; Toratani, H.; Takeda, A.

    In order to examine whether or not radioactivity could be produced in black pepper and white pepper with 10MeV electrons, the sample was irradiated with 10MeV electrons from a linear accelerator and its radioactivity was measured by gamma-ray spectrometry and beta-ray counting. The patterns of gamma-ray spectra showed that there was no difference between the irradiated and the non-irradiated samples, suggesting that the induced radioactivity in the irradiated sample was below the detection limit of its induced radioactivity. For further estimation, elemental composition was analyzed and photonuclear reactions which could produce radioactivity in the sample were investigated based on the data already published. Some photonuclear target nuclides in the list were spiked to the sample, being checked in the same way. Although short lived photonuclear products were observed, these radioactivities were found to decrease below the detection limit in a week. It is concluded that the induced radioactivity in the 10MeV electron-irradiated pepper and hence, its biological effect is far smaller than the natural radioactivity arising from 40K contained in the non-irradiated sample.

  17. Radioactivity

    Large amounts of radioactivity can be released in nuclear accidents and nuclear explosions. Important events since the atomic bombs of 1945 are listed more or less in chronological order, including the nuclear weapons tests after World War II and the accidents recorded in nuclear facilities. (DG)

  18. Preliminary examination of induced radioactivity in pepper by 10 MeV electron irradiation

    β-ray measurement was performed on 10 MeV electron-irradiated black pepper and white pepper with liquid scintillation counter in order to reconfirm the wholesomeness of irradiated foods and present unambiguous data to general consumers concerning about the induced radioactivity in the irradiated foods. In irradiated black pepper no radioactivity other than from natural source, un-irradiated one, was detected. But in irradiated white pepper, it was suggested that induced radioactivity might be detected if the detection method was more improved. (author)

  19. Exploring thermally induced states in square artificial spin-ice arrays

    We present a methodology to explore experimentally the formation of thermally induced long-range ground-state ordering in artificial spin-ice systems. Our novel approach is based on the thermalization from a square artificial spin-ice array of elongated ferromagnetic nanoislands made of a FeNi alloy characterized by a Curie temperature about 100 K lower than that of Permalloy (Ni81Fe19), which is commonly used for this kind of investigation. The decrease in M(T) when the sample is heated close to its Curie temperature reduces the shape anisotropy barrier of each island and allows us to bring the artificial spin-ice pattern above the blocking temperature of the islands, thus ‘melting’ the spin-ice system, without damaging the sample. The magnetization configuration resulting from the thermal excitation of the islands and the frustrated dipolar interactions among them can be then imaged by magnetic force microscopy or any other kind of magnetic microscopy imaging after cooling down the sample back to room temperature. This thermally induced melting–freezing protocol can be repeated as many times as desired on the same sample and the heating and cooling parameters (max T, heating and cooling rates, number of cycles, application of external fields) varied at will. Thereby, the approach proposed here opens up a pathway to the systematic experimental study of thermally induced frozen states in artificial spin-ice systems, which have been the subject of many recent theoretical studies due to their interesting physical properties but, because of the difficulties in obtaining them in real samples and in a controlled manner, remain experimentally an almost completely unexplored terrain. (paper)

  20. Radioactivity of tobacco leaves and radiation dose induced from smoking.

    Papastefanou, Constantin

    2009-02-01

    The radioactivity in tobacco leaves collected from 15 different regions of Greece and before cigarette production was studied in order to find out any association between the root uptake of radionuclides from soil ground by the tobacco plants and the effective dose induced to smokers from cigarette tobacco due to the naturally occurring primordial radionuclides , such as 226Ra and 210Pb of the uranium series and 228Ra of the thorium series and/or man-made radionuclides, such as 137Cs of Chernobyl origin. Gamma-ray spectrometry was applied using Ge planar and coaxial type detectors of high resolution and high efficiency. It was concluded that the activities of the radioisotopes of radium, 226Ra and 228Ra in the tobacco leaves reflected their origin from the soil by root uptake rather than fertilizers used in the cultivation of tobacco plants. Lead-210 originated from the air and was deposited onto the tobacco leaves and trapped by the trichomes. Potassium-40 in the tobacco leaves was due to root uptake either from soil or from fertilizer. The cesium radioisotopes 137Cs and 134Cs in tobacco leaves were due to root uptake and not due to deposition onto the leaf foliage as they still remained in soil four years after the Chernobyl reactor accident, but were absent from the atmosphere because of the rain washout (precipitation) and gravitational settling. The annual effective dose due to inhalation for adults (smokers) for 226Ra varied from 42.5 to 178.6 microSv/y (average 79.7 microSv/y), while for 228Ra from 19.3 to 116.0 microSv/y (average 67.1 microSv/y) and for 210Pb from 47.0 to 134.9 microSv/y (average 104.7 microSv/y), that is the same order of magnitude for each radionuclide. The sum of the effective doses of the three radionuclides varied from 151.9 to 401.3 microSv/y (average 251.5 microSv/y). The annual effective dose from 137Cs of Chernobyl origin was three orders of magnitude lower as it varied from 70.4 to 410.4 nSv/y (average 199.3 nSv/y). PMID:19440399

  1. Radioactivity of Tobacco Leaves and Radiation Dose Induced from Smoking

    Constantin Papastefanou

    2009-02-01

    Full Text Available The radioactivity in tobacco leaves collected from 15 different regions of Greece and before cigarette production was studied in order to find out any association between the root uptake of radionuclides from soil ground by the tobacco plants and the effective dose induced to smokers from cigarette tobacco due to the naturally occurring primordial radionuclides , such as 226Ra and 210Pb of the uranium series and 228Ra of the thorium series and/or man-made radionuclides, such as 137Cs of Chernobyl origin. Gamma-ray spectrometry was applied using Ge planar and coaxial type detectors of high resolution and high efficiency. It was concluded that the activities of the radioisotopes of radium, 226Ra and 228Ra in the tobacco leaves reflected their origin from the soil by root uptake rather than fertilizers used in the cultivation of tobacco plants. Lead-210 originated from the air and was deposited onto the tobacco leaves and trapped by the trichomes. Potassium-40 in the tobacco leaves was due to root uptake either from soil or from fertilizer. The cesium radioisotopes 137Cs and 134Cs in tobacco leaves were due to root uptake and not due to deposition onto the leaf foliage as they still remained in soil four years after the Chernobyl reactor accident, but were absent from the atmosphere because of the rain washout (precipitation and gravitational settling. The annual effective dose due to inhalation for adults (smokers for 226Ra varied from 42.5 to 178.6 μSv/y (average 79.7 μSv/y, while for 228Ra from 19.3 to 116.0 μSv/y (average 67.1 μSv/y and for 210Pb from 47.0 to 134.9 μSv/y (average 104.7 μSv/y, that is the same order of magnitude for each radionuclide. The sum of the effective doses of the three radionuclides varied from 151.9 to 401.3 μSv/y (average 251.5 μSv/y. The annual effective dose from 137Cs of Chernobyl origin was three orders of magnitude lower as it varied from 70.4 to 410.4 nSv/y (average 199.3 nSv/y.

  2. Emanations and ``induced'' radioactivity: From mystery to (mis)use

    Kolar, Z. I.

    1999-01-01

    Radon, Rn; atomic number Z=85; is a (gaseous) chemical element of which no stable but only radioactive isotopes exist. Three of them, namely actinon (219Rn), thoron (220Rn) and radon (222Rn) are the decay products of naturally occurring radioisotopes of radium:223Ra,224Ra and226Ra, respectively. The natural Rn isotopes were discovered within the period 1899-1902 and at that time referred to as emanations because they came out (emanated) of sources/materials containing actinium, thorium and radium, respectively. The (somewhat mysterious) emanations appeared to disintegrate into radioactive decay products which by depositing at solid surfaces gave rise to “induced” radioactivity i.e. radioactive substances with various half-lives. Following the discovery of the emanations the volume of the research involving them and their disintegration products grew steeply. The identity of a number of these radioactive products was soon established. Radium- emanation was soon used as a source of RaD (210Pb) to be applied as an “indicator” (radiotracer) for lead in a study on the solubility of lead sulphide and lead chromate. Moreover, radium and its emanation were introduced into the medical practice. Inhaling radon and drinking radon-containing water became an accepted medicinal use (or misuse?) of that gas. Shortly after the turn of the century, the healing (?) action of natural springs (spas) was attributed to their radium emanation i.e. radon. Bathing in radioactive spring water and drinking it became very popular. Even today, bathing in radon-containing water is still a common medical treatment in Jáchymov, Czech Republic.

  3. Evaluation of induced radioactivity in 10 MeV electron-irradiated spices

    In order to make clear appreciation to induced radioactivity in the irradiated foods, photonuclear reactions which could produce radioactivity at energies up to 10 MeV were listed up from elemental compositions of black pepper, white pepper, red pepper, ginger and turmeric. The samples were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy and radioactivity was measured. Induced radioactivity could not be detected significantly by gamma-ray spectrometry and beta-ray counting in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H50 according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from 40K contained in the samples. (J.P.N.)

  4. Evaluation of induced radioactivity in 10 MeV electron-irradiated spices

    Furuta, Masakazu; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Katayama, Tadashi; Toratani, Hirokazu (Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology); Takeda, Atsuhiko

    1993-10-01

    In order to make clear appreciation to induced radioactivity in the irradiated foods, photonuclear reactions which could produce radioactivity at energies up to 10 MeV were listed up from elemental compositions of black pepper, white pepper, red pepper, ginger and turmeric. The samples were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy and radioactivity was measured. Induced radioactivity could not be detected significantly by gamma-ray spectrometry and beta-ray counting in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H[sub 50] according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from [sup 40]K contained in the samples. (J.P.N.).

  5. Electromagnetically induced transparency using a superconducting artificial atom with optimized level anharmonicity

    Shao, Zhu-Lei; Feng, Zhi-Bo

    2016-04-01

    We propose a theoretical scheme to implement electromagnetically induced transparency (EIT) using an artificial atom of superconducting circuit. Allowed by the selection rule, two kinds of interactions between the atom and driving fields can be obtained, in which we focus on the leakage effect. In terms of dark-state mechanism in generating EIT, the leakage could destroy the EIT considerably. By removing the leakage effect in an optimized three-level atom, we consider a realization of EIT through the technique of density matrix. Furthermore, another effective way to optimize the level anharmonicity is analyzed in a dressing-state method. The scheme could provide a promising approach for experimentally improving EIT with the artificial atoms.

  6. Radioactivity

    This bulletin supplements UK radioactivity data published in Chapter 4 of the Digest of Envirnomental Protection and Water Statistics No 11 1988 (HMSO 1989). The data are presented in three sections: (a) annual emissions (gaseous liquid and solid) by site, and trends in volume; (b) annual concentrations, particularly of drinking water, strontium 90 and caesium 137; (c) estimation of collective doses from fish and shellfish consumption in the U.K. and Europe, and summary of committed dose equivalents to a one-year old infant from milk consumption in the U.K. (UK)

  7. Magnitude, course of time and correlations of the total, lead and artificially radioactive suspended dust pollutants in a stress border area

    The average total suspended dust concentration of 56 ?g/m3 in the stress border area around Iserlon lies within the range of the clean air area values and amounts only to about the half the mean value in the Ruhr stress area. The mean lead suspended dust stress of 0.21 ?g/m3, however, is about 8 times higher than in the clean air areas and about 3 times lower than in the stress area. On sundays the total suspended dust concentration is reduced to 82% and the lead suspended dust concentration to 40% of the week-day value. The artificial suspended dust radioactivity seems to be within the range of the average in West Germany. Lead concentration and suspended dust radioactivity are far extendingly independent of the total suspended dust stress. (orig.)

  8. Induced radioactivity in interior beam probe for low-energy proton cyclotron

    Both theoretical analysis and Monte-Carlo simulation on induced radioactivity in the copper measuring probe irradiated by proton beams with energy of 11 MeV and intensity of 50 ?A have been demonstrated. Saturated activities of various kinds of radioactive nuclides obtained by these two methods were compared. The comparison indicates that the Monte-Carlo method conducted by software FLUKA can provide good simulation accuracy and complete consideration in nuclear reaction, and both the direct and indirect radioactivity under different irradiation time can be calculated simultaneously. The method can also provide accurate analysis and prediction on the induced radioactivity in different measuring probes under proton irradiation, which will provide a reference for design, exchange and disposal of the probes. (authors)

  9. Studies of muon-induced radioactivity at NuMI

    Boehnlein, David j.; Leveling, A.F.; Mokhov, N.V.; Vaziri, K.; /Fermilab; Iwamoto, Y.; Kasugai, Y.; Matsuda, N.; Nakashima, H.; Sakamoto, Y.; /JAEA, Ibaraki; Hagiwara, M.; Iwase, Hiroshi; /KEK, Tsukuba /Kyoto U., KURRI /Pohang Accelerator Lab. /Shimizu, Tokyo /Tohoku U.

    2009-12-01

    The JASMIN Collaboration has studied the production of radionuclides by muons in the muon alcoves of the NuMI beamline at Fermilab. Samples of aluminum and copper are exposed to the muon field and counted on HpGe detectors when removed to determine their content of radioactive isotopes. We compare the results to MARS simulations and discuss the radiological implications for neutrino factories and muon colliders.

  10. Studies of muon-induced radioactivity at NuMI

    The JASMIN Collaboration has studied the production of radionuclides by muons in the muon alcoves of the NuMI beamline at Fermilab. Samples of aluminum and copper are exposed to the muon field and counted on HpGe detectors when removed to determine their content of radioactive isotopes. We compare the results to MARS simulations and discuss the radiological implications for neutrino factories and muon colliders.

  11. Pinning of a single Abrikosov vortex in superconducting Nb thin films using artificially induced pinning sites

    Artificial structures were intentionally introduced into Nb films in order to study the interaction of a single Abrikosov vortex with pinning sites caused by these known defects. A vortex trapped on one of these structures or defects can be induced to move either by thermal depinning or by pushing on the vortex with a transport current in one of the films. The resulting motion, in turn, can be followed by observing the changes in the Fraunhofer-like interference pattern of a cross-strip Josephson junction having the thin film as one leg of the junction. Artificial pinning sites were successfully created by depositing Fe balls on the surface of a previously characterized thin film. Attempts to create artificial pinning sites by depressing the order parameter with a thin strip of Au on the surface of the Nb were not successful. There was no correlation between the location of trapped vortices and the location of the Au line. In a separate measurement, Lorentz-force-depinning studies for several intrinsic pinning sites in the thin film show that a transport current in the top film will depin a vortex in the top film with about one-tenth the current needed in the bottom film to depin the same vortex. (c) 2000 The American Physical Society

  12. Artificial neural network for on-site quantitative analysis of soils using laser induced breakdown spectroscopy

    Nowadays, due to environmental concerns, fast on-site quantitative analyses of soils are required. Laser induced breakdown spectroscopy is a serious candidate to address this challenge and is especially well suited for multi-elemental analysis of heavy metals. However, saturation and matrix effects prevent from a simple treatment of the LIBS data, namely through a regular calibration curve. This paper details the limits of this approach and consequently emphasizes the advantage of using artificial neural networks well suited for non-linear and multi-variate calibration. This advanced method of data analysis is evaluated in the case of real soil samples and on-site LIBS measurements. The selection of the LIBS data as input data of the network is particularly detailed and finally, resulting errors of prediction lower than 20% for aluminum, calcium, copper and iron demonstrate the good efficiency of the artificial neural networks for on-site quantitative LIBS of soils. - Highlights: ► We perform on-site quantitative LIBS analysis of soil samples. ► We demonstrate that univariate analysis is not convenient. ► We exploit artificial neural networks for LIBS analysis. ► Spectral lines other than the ones from the analyte must be introduced

  13. Status and perspectives of the surveillance of artificial radioactivity in the environment in Europe and of the international exchange of radiological data

    After the Chernobyl accident systems for the surveillance of artificial radioactivity and for the international exchange of radiological data have been upgraded or established all over Europe. They include both site-specific as well as nation-wide systems and programmes. The modules of the systems for the surveillance of artificial radioactivity are on-line networks (mostly gamma dose rate and air concentration) with fixed stations, mobile units (ground based and airborne) and specialized laboratories which are capable of performing as a minimum requirement high resolution gamma ray spectrometric measurements of various types of environmental samples. In general, the technical standard of the European surveillance systems is very high. The systems have been designed mostly to meet national requirements. As a consequence, the situation in Europe as a whole is inhomogeneous and there is a need for quality assurance programmes at the European level. The establishment of the existing systems for the international exchange of radiological data and information is based on bilateral, multilateral and international agreements. They cover the whole spectrum from site specific bilateral agreements for NPPs near national borders to international agreement between all member states of the European Union (ECURIE). (author)

  14. Induced radioactivity in a 4 MW target and its surroundings

    Agosteo, Stefano; Otto, Thomas; Silari, Marco

    2003-01-01

    An important aspect of a future CERN Neutrino Factory is the material activation arising from a 2.2 GeV, 4 MW proton beam striking a mercury target. An estimation of the hadronic inelastic interactions and the production of residual nuclei in the target, the magnetic horn, the decay tunnel, the surrounding rock and a downstream dump was performed by the Monte Carlo hadronic cascade code FLUKA. The aim was both to assess the dose equivalent rate to be expected during maintenance work and to evaluate the amount of residual radioactivity, which will have to be disposed of after the facility has ceased operation.

  15. Evaluation of induced radioactivity in structural material of Toshiba Training Reactor 'TTR1'

    A decommissioning programme for the Toshiba Training Reactor (TTR1), a swimming pool type reactor used for reactor physics experiments and material irradiation, was started in August 2001. As a part of the programme, induced radioactivity in structural material was evaluated using neutron flux data obtained with the three-dimensional Sn code TORT. Induced activity was calculated with the isotope generation code ORIGEN-79 using activation cross section data created from multi-group library based on JENDL-3. The obtained results for radioactivities such as 60Co, 65Zn, 54Mn and 152Eu were compared with measured ones, and the present calculational method was confirmed to have enough accuracy. (authors)

  16. Evaluation of induced radioactivity in 10 MeV-electron irradiated spices, (1); [gamma]-ray measurement

    Furuta, Masakazu; Katayama, Tadashi; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Shibata, Setsuko; Toratani, Hirokazu (Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology); Takeda, Atsuhiko

    1994-02-01

    Black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electrons from a linear accelerator to a dose of 100 kGy and radioactivity was measured in order to estimate induced radioactivity in the irradiated foods. Induced radioactivity could not be detected significantly by [gamma]-ray spectrometry in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list of photonuclear reactions which could produce radioactivity below 10 MeV. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H[sub 50] according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from [sup 40]K contained in the samples. (author).

  17. Determination and mapping the spatial distribution of radioactivity of natural spring water in the Eastern Black Sea Region by using artificial neural network method.

    Ye?ilkanat, Cafer Mert; Kobya, Ya?ar

    2015-09-01

    In this study, radiological distribution of gross alpha, gross beta, (226)Ra, (232)Th, (40)K, and (137)Cs for a total of 40 natural spring water samples obtained from seven cities of the Eastern Black Sea Region was determined by artificial neural network (ANN) method. In the ANN method employed, the backpropagation algorithm, which estimates the backpropagation of the errors and results, was used. In the structure of ANN, five input parameters (latitude, longitude, altitude, major soil groups, and rainfall) were used for natural radionuclides and four input parameters (latitude, longitude, altitude, and rainfall) were used for artificial radionuclides, respectively. In addition, 75 % of the total data were used as the data of training and 25 % of them were used as test data in order to reveal the structure of each radionuclide. It has been seen that the results obtained explain the radiographic structure of the region very well. Spatial interpolation maps covering the whole region were created for each radionuclide including spots not measured by using these results. It has been determined that artificial neural network method can be used for mapping the spatial distribution of radioactivity with this study, which is conducted for the first time for the Black Sea Region. PMID:26307690

  18. Rapid method of gamma-ray does rates for distinction between natural and artificial radioactive nuclides using portable NaI(Tl) scintillation measurement system

    When evaluating an environmental ?-ray dose rates, it is important to determine the individual contributions of both natural and artificial radioactive nuclides to the overall measured rate. In areas where nuclear contamination is suspected, however, it can be difficult to rapidly ascertain these relative contributions. This paper describes the use of a portable NaI(T1) scintillation spectrometer to quickly and accurately measure ?-ray dose rates at 16 locations in Japan, in order to construct a contamination map on an emergency basis. The survey data showed that, in locations with differing energy distributions, there were noticeable correlations between the total ?-ray dose and the count rates within the specific energy ranges of 1400 - 3000, 1650 - 3000 and 1800 - 3000 keV, and these correlations differed markedly between natural and artificial nuclides. These observations suggested that the artificial nuclide contribution to the ?-ray dose rate could be calculated using the correlations, and subsequent analysis of the data confirmed that this was possible. The resulting estimates were accurate to within approximately 3.3, 0 and 10% within the energy ranges of 1400 - 3000, 1650 - 3000 and 1800 - 3000 keV as the 30 nGy/h, respectively. (author)

  19. Diffusion of the 241Am ? 237Np decay chain limited by their elemental solubilities in the artificial barriers of high-level radioactive waste repositories

    A mathematical analysis of the diffusion of the 241Am ? 237Np decay chain in the artificial barrier of a high-level radioactive waste repository is presented. First, analytical solutions obtained are for the space- and time-dependent concentration of 241Am in the artificial barrier and the time-dependent amount of americium precipitated at the surface of the waste glass, based on the assumption of the congruency of the radionuclides with solubility-limited dissolution of the glass matrix. The effects of solubility sharing with coexisting 243Am are considered. Transport and precipitation of 237Np in the artificial barrier are analyzed by dividing the time domain into a small time domain, where the 241Am concentration is so large that 237Np precipitation is dominant, and a large time domain, where the 241Am becomes negligible and the precipitation region shrinks by diffusion from the precipitation front. The equation for the movement of the precipitation front is obtained. As the overpack lifetime increases, the effect of neptunium precipitation becomes less significant. With a lifetime longer than ?6000 yr, an earlier model, where neptunium is treated as a mother nuclide and the precipitation occurs only at the glass surface, can be used

  20. Percutaneous Ethanol Injection via an Artificially Induced Right Hydrothorax for Hepatocellular Carcinoma in the Hepatic Dome

    To evaluate the efficacy of sonographically (US) guided percutaneous ethanol injection (PEI) via an artificially induced right hydrothorax (transthoracic PEI) to treat US-invisible hepatocellular carcinoma (HCC) in the hepatic dome. Five cirrhotic patients with US-invisible HCC in the hepatic dome, who were poor surgical candidates, underwent transthoracic PEI. An artificial right hydrothorax was created by instilling 500 ml saline, and absolute ethanol was injected transhydrothoracically into the hepatic dome lesion under local anesthesia. The success and complications were assessed radiologically. The patients were followed up serologically and radiologically for 12-44 (mean 28.4) months. Twenty-five hydrothoraces were induced. All hydrothoraces enabled US visualization of the entire hepatic dome. Eight of the nine small lesions were treated successfully by the treatment. Two of the three local recurrences were eradicated by repeat transthoracic PEI. One large lesion was treated by a combination of transthoracic and regular PEI. The only complication was one clinically insignificant pneumothorax. Induction of a right hydrothorax is feasible and safe. The hydrothorax enables US visualization of the entire hepatic dome and permits US-guided PEI for HCC in the hepatic dome that otherwise would not be possible

  1. A radiation-induced breast cancer following artificial pneumothorax therapy for pulmonary tuberculosis

    A case of radiation-induced breast cancer in a woman who had been fluoroscopied repeatedly for control of pneumothorax for pulmonary tuberculosis 35 years before is reported. The breast tissue presumably received about 136 rads or less in three and a half years. In Japan, both prospective and retrospective surveies following multiple fluoroscopies during artificial pneumothorax collaps therapy have failed to show an increase in the risk of subsequent development of primary breast cancer. The dose given to breast tissues in Japanese patients was generally far less than that in the MacKenzie's series. A radiation-induced breast cancer in Japanese literature has not yet been reported. It seems that the lesser doses may explain the reason of this fact. (auth.)

  2. A history of study on safety of irradiated foods (3). Induced radioactivity in irradiated foods

    Food irradiation can induce a small amount of radioactivity in the foods. The principal mechanisms of the nuclear reactions are (n, γ), (γ, n), (γ, γ'). The resulting nuclear products were found in irradiated foods were Na-24, P-32, Ca-45, C-11, N-13, and O-15 in the food irradiated by 24 MeV electron beam. The total radioactivity is less than 1/1000 of those of K-40 in the case of electron beams below 10 MeV or X rays below 5 MeV. Package materials affected neutron flux in the foods and enhanced the radioactivity. Electron beam machine produces neutrons and increases the flux in food. IAEA recommend to reduce neutron production in the facility. The safety of irradiated food in the radioactivity field still needs more progress. (author)

  3. Measurement of radioactivity induced by GeV-protons and spallation neutrons using AGS accelerator

    Measurement of radioactivity induced by high-energy protons with energy of 2.83 and 24 GeV and spallation neutrons produced by bombarding a mercury target with the high-energy protons were performed by using the AGS (Alternative Gradient Synchrotron) accelerator at Brookhaven National Laboratory. The samples of boron, carbon, aluminum, iron, copper, niobium, mercury-oxide, lead, bismuth, acrylic resin, SS-316, Inconel-625 and Inconel-718 were irradiated around the mercury target. After the irradiation, the radioactivity of each sample was measured by using HPGe detectors at the cooling time between 2 h and 200 d. In the processing of the measured γ-ray spectra, more than 90 radioactive nucleus were identified, and the radioactivity production data were obtained. This report gives the experimental procedure, the data processing and the experimental results. (author)

  4. Manifestation of the influence of releases of artificial long-lived radionuclides seen against the background of global radioactive contamination of the Atlantic Ocean and related seas

    The authors note an analogy in the behaviour of artificial and natural radionuclides in the ocean. A seasonal tendency is observed in the variations of 90Sr concentrations due to global fall-out in surface waters of the North Atlantic (200N-700N latitude), and an empirical formula is suggested to describe the observed seasonality. The results are given of 90Sr, 137Cs and 134Cs determinations carried out by the authors in the surface waters of the North Sea, and of 90Sr and 137Cs determinations made in surface waters of the southern part of the Baltic Sea. A comparison with data from the literature shows that the release of radioactive materials beyond the norms laid down in the London Dumping Convention of 1952 led to serious contamination of the North Sea, to levels in fact which were considerably in excess of the global radioactive contamination for 1963. Through the normal processes of turnover and interchange of water masses, the resultant radioactive impurities entered the Baltic Sea. In 1979 the influx of 137Cs from the North Sea into the Baltic was ten times greater than the influx through river discharge. However, in surface waters near the straits in the south and south-west part of the Baltic no increased concentration of 137Cs was found in 1979. (author)

  5. Influence of ion bombardment induced patterning of exchange bias in pinned artificial ferrimagnets on the interlayer exchange coupling

    Artificial ferrimagnets (AFi) have many applications as, e.g., pinned reference electrodes in magnetic tunnel junctions. It is known that the application of ion bombardment induced magnetic patterning with He ions on a single layer reference electrode of magnetic tunnel junctions is possible. For some applications a combination of ion bombardment induced magnetic patterning and artificial ferrimagnets as a reference electrode is desirable. The effect of ion bombardment induced magnetic patterning on pinned artificial ferrimagnets with a Ru interlayer which is frequently used in magnetic tunnel junctions as well as pinned AFis with a Cu interlayer has been tested. Special attention has been given to the question whether the antiferromagnetic interlayer exchange coupling can withstand the ion dose necessary to turn the exchange bias

  6. Computational Analysis of Artificial Gravity as a Possible Countermeasure to Spaceflight Induced Bone Loss

    Mulugeta, L.; Werner, C. R.; Pennline, J. A.

    2015-01-01

    During exploration class missions, such as to asteroids and Mars, astronauts will be exposed to reduced gravity for extended periods. Data has shown that astronauts lose bone mass at a rate of 1% to 2% a month in microgravity, particularly in lower extremities such as the proximal femur. Exercise countermeasures have not completely eliminated bone loss from long duration spaceflight missions, which leaves astronauts susceptible to early onset osteoporosis and greater risk of fracture. Introduction of the Advanced Resistive Exercise Device and other large exercise devices on the International Space Station (ISS), coupled with improved nutrition, has further minimized bone loss. However, unlike the ISS, exploration vehicles will have very limited volume and power available to accommodate such capabilities. Therefore, novel concepts like artificial gravity systems are being explored as a means to provide sufficient load stimulus to the musculoskeletal system to mitigate bone changes that may lead to early onset osteoporosis and increased risk of fracture. Currently, there is minimal data available to drive further research and development efforts to appropriately explore such options. Computational modeling can be leveraged to gain insight on the level of osteoprotection that may be achieved using artificial gravity produced by a spinning spacecraft or centrifuge. With this in mind, NASA's Digital Astronaut Project (DAP) has developed a bone remodeling model that has been validated for predicting volumetric bone mineral density (vBMD) changes of trabecular and cortical bone both for gravitational unloading condition and the equivalent of 1g daily load stimulus. Using this model, it is possible to simulate vBMD changes in trabecular and cortical bone under different gravity conditions. In this presentation, we will discuss our preliminary findings regarding if and how artificial gravity may be used to mitigate spaceflight induced bone loss.

  7. Development of a method for plasma - induced combustion of intermediate to low-level radioactive waste

    Nachtrodt, Frederik

    2013-01-01

    This work demonstrates that the plasma - induced combustion of intermediate to low-level radioactive waste is a suitable method for volume reduction and stabilization. Weaknesses of existing facilities can be overcome with novel developments. Plasma treatment of LILW has a high economical advantage by volume reduction for storage in final repositories.

  8. Induced radioactivity of steel components in industrial flaw inspection with electron accelerators

    The results are presented of experimental investigations of the characteristics of gamma radiation of induced radioactivity of steel components and also of structural members of the accelerator/flaw detector. Semiempirical equations are proposed for determining the holding time of inspected components and the betatron which take into account the focusing distance, exposure time, and braking radiation intensity

  9. Structure effects on reaction mechanisms in collisions induced by radioactive ion beams

    The present paper concerns the study of reactions induced by radioactive beams of halo and weakly bound nuclei at energies around and above the Coulomb barrier. The results obtained for the reaction induced by the halo nucleus 6He on 64Zn have been compared with the results for the reaction induced by 4He on the same target. The results of the reaction induced by the weakly bound unstable 13N on the weakly bound 9Be have been compared with those for the reaction 10B + 12C

  10. Remineralization efficiency of bioactive glass on artificially induced carious lesion an in-vitro study

    Sai Sathya Narayana

    2014-01-01

    Full Text Available Objectives: The objective of this study is to investigate the efficacy of bioactive glass containing product on remineralization of artificial induced carious enamel lesion and to compare its efficiency with other remineralization products using an in-vitro pH cycling method. The null hypothesis tested was bioactive glass has no effect on enamel remineralization. Materials and Methods: A total of 20 enamel samples of human molar teeth were subjected to artificial caries lesion formation using pH cycling method and was verified using high resolution scanning electron microscope (HRSEM. Each demineralized sample was then divided into five test groups each containing twenty. Group A - Bioactive glass (SHY-NM, Group B - Fluoride tooth paste (Amflor, Group C - CPP-ACP (Tooth mousse, Group D - CPP-ACPF (Tooth mousse plus, Group E - control. All the test groups were exposed to the pH cycling regime, the remineralizing agents were applied for 10 min except control. After 10 days period, the entire test groups were evaluated with HRSEM and quantitative assessment by energy dispersive X-ray spectroscopy. The obtained data was analyzed statistically using one-way ANOVA, Student′s t-test and Tukey′s multiple comparison tests. P ≤ 0.05 was considered to be significant. Results: Rejection of the null hypothesis and highlights the concept of biomimetic bioactive glass as an effective remineralizing agent. Clinical Relevance: To focus on the importance of minimal invasive treatment on incipient carious lesion by remineralization.

  11. Earthquake-induced landslide-susceptibility mapping using an artificial neural network

    S. Lee

    2006-01-01

    Full Text Available The purpose of this study was to apply and verify landslide-susceptibility analysis techniques using an artificial neural network and a Geographic Information System (GIS applied to Baguio City, Philippines. The 16 July 1990 earthquake-induced landslides were studied. Landslide locations were identified from interpretation of aerial photographs and field survey, and a spatial database was constructed from topographic maps, geology, land cover and terrain mapping units. Factors that influence landslide occurrence, such as slope, aspect, curvature and distance from drainage were calculated from the topographic database. Lithology and distance from faults were derived from the geology database. Land cover was identified from the topographic database. Terrain map units were interpreted from aerial photographs. These factors were used with an artificial neural network to analyze landslide susceptibility. Each factor weight was determined by a back-propagation exercise. Landslide-susceptibility indices were calculated using the back-propagation weights, and susceptibility maps were constructed from GIS data. The susceptibility map was compared with known landslide locations and verified. The demonstrated prediction accuracy was 93.20%.

  12. Preliminary examination of induced radioactivity in black pepper by 10 MeV electron irradiation

    In spite of the wholesomeness acceptance of irradiated foods by the FAO/IAEA/WHO Joint Expert Committee on Food Irradiation 1981, there are some concerns about its safety, in which the induced radioactivity in the irradiated foods is the matter of primary concern. It is, therefore, very important to show clear data of radioactivity in irradiated foods to the public in order to clear up their misunderstanding. Especially for irradiated spices, this is an urgent problem because they are expected to circulate in the international market in the near future. Therefore, in this study, the authors tried to examine whether or not radioactivity could be induced in the black pepper irradiated with 10 MeV electrons theoretically and experimentally. For the theoretical evaluation, elemental composition of the sample were analyzed and photonuclear reactions which could produce radioactivity in the sample were investigated based on the data already published. Then the sample was irradiated with 10 MeV electrons from the linear accelerator and radioactivity was measured by gamma-ray spectrometry. As a result, the pattern of gamma-ray spectra was all the same between irradiated sample and background. (author)

  13. Radioactivity. Centenary of radioactivity discovery

    This small booklet was edited for the occasion of the exhibitions of the celebration of the centenary of radioactivity discovery which took place in various locations in France from 1996 to 1998. It recalls some basic knowledge concerning radioactivity and its applications: history of discovery, atoms and isotopes, radiations, measurement of ionizing radiations, natural and artificial radioactivity, isotope dating and labelling, radiotherapy, nuclear power and reactors, fission and fusion, nuclear wastes, dosimetry, effects and radioprotection. (J.S.)

  14. Development of the two-phase flow induced force fluctuation predictive tool using artificial void signal

    In this study, fluctuating force acting on pipe turning section due to two-phase flow is considered. A novel tool to predict upward two-phase flow induced force fluctuations is developed. In order to eliminate tool's dependencies on experimental measurement input, creation of artificial void signal (AVS) was considered by carefully analyzing area-averaged void fraction properties, including probability density and frequency spectra from 36 flow conditions. Generated AVS was successfully coupled with the predictive tool, and as a result, it is capable of predicting fluctuating force magnitude and dominant force frequency from the inlet superficial velocities alone. The tool is applicable for small inner diameter pipe (<∼10 cm) consist of 0-90 degree turning element, and covers two-phase flow regime up to churn-turbulent flow. (author)

  15. New estimation of La Hague contribution to the artificial radioactivity of Norwegian waters (1992-1995) and Barents Sea (1992-1997)

    A release of 10,000 GBq per month of a conservative radionuclide into the central part of the English Channel gives rise to activities (in Bq m-3) of 6 8-89 at Goury, 50-70 in Cherbourg (5 and 30 km from the waste outlet of La Hague), 25-40 in the Straits of Dover, 4-5 at the entrance of the Norwegian Channel and 1-3 at the entrance of the Barents Sea. Taking account of La Hague releases and transit times of 17 and 36 months, a calculation of the contribution of La Hague to the artificial radioactivity of the entrance to the Norwegian Channel and the Barents Sea is given

  16. Application of artificial neural networks on the characterization of radioactive waste drums; Aplicacao de redes neurais artificiais na caracterizacao de tambores de rejeito radioativo

    Potiens Junior, Ademar Jose; Hiromoto, Goro, E-mail: apotiens@ipen.b, E-mail: hiromoto@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-10-26

    The methodology consist of system simulation of drum-detector by Monte Carlo for obtention of counting efficiency. The obtained data were treated and a neural artificial network (RNA) were constructed for evaluation of total activity of drum. For method evaluation measurements were performed in ten position parallel to the drum axis and the results submitted to the RNA. The developed methodology showed to be effective for isotopic characterization of gamma emitter radioactive wastes distributed in a heterogeneous way in a 200 litters drum. The objective of this work as to develop a methodology of analyse for quantification and localization of radionuclides not homogeneous distributed in a 200 liters drum based on the mathematical techniques

  17. Environmental radioactivity in Caithness and Sutherland. Pt. 10: Studies of artificial radioactivity in the coastal environment of Northern Scotland: a review

    This review brings together measurements which have been made over the last 10-15 years of the concentrations of a number of artificial radionuclides in various media in the northern Scottish coastal environment. The radionuclides include 60Co, 90Sr, 134Cs, 137Cs, 238Pu, 239,240Pu and 241Am. The media include nearshore and offshore seawater, beach sand and sediments, seaweeds, winkles, spume, deposits on rocks and soils, sheep faeces and atmospheric deposition. The various radionuclide sources which contribute to the study area are described. Some transfer mechanisms which operate between different media for different radionuclides are discussed, and the radiological significance of the observed radionuclide concentrations is briefly described. (UK)

  18. Induced radioactivity in air and water at medical accelerators

    Activation of air and water has been evaluated at the 10 and 15 MeV linear electron accelerator facilities. At 15 MeV irradiation, the activity of 10-min-half-life 13N was observed in the case of the air in the glove box. Air and water samples were also bombarded by 250 MeV protons and 400 MeV/u carbon, and the irradiation dose was 10 Gy at the isocenter. Upon the ion-chamber monitoring of the air sampled from the glove box, 15O, 13N, and 11C activities were mainly observed. At the end of proton and carbon irradiation, the activity of the water was found to be about 10 kBq·cm-3 and several kBq·cm-3, respectively. From the decay analysis of the induced activity in water, 15O, 13N, and 11C were detected. (author)

  19. Artificial radioactivity in edible parts of giant clam mollusc from Mururoa atoll from 1967 to 1990. Health physics aspect

    Radionuclides concentration by giant clams is associated with feeding habit. It's also a main food for polynesian atolls inhabitants, elsewhere than Mururoa island because this mollusc is not consumed like all the other fishery products from this atoll lagoon. Nevertheless measurements of ten artificial radionuclides are performed in edible parts of giant clams fished from Mururoa lagoon since the beginning of nuclear tests. The decay of radionuclides concentration is described versus time. To go further on we have computed the dose-equivalent for internal exposure of an eventual giant clams eater. It is estimated that the resulting risk of malignancy is below than 1 per 10 000

  20. Rainfall and earthquake-induced landslide susceptibility assessment using GIS and Artificial Neural Network

    Y. Li

    2012-08-01

    Full Text Available A GIS-based method for the assessment of landslide susceptibility in a selected area of Qingchuan County in China is proposed by using the back-propagation Artificial Neural Network model (ANN. Landslide inventory was derived from field investigation and aerial photo interpretation. 473 landslides occurred before the Wenchuan earthquake (which were thought as rainfall-induced landslides (RIL in this study, and 885 earthquake-induced landslides (EIL were recorded into the landslide inventory map. To understand the different impacts of rainfall and earthquake on landslide occurrence, we first compared the variations between landslide spatial distribution and conditioning factors. Then, we compared the weight variation of each conditioning factor derived by adjusting ANN structure and factors combination respectively. Last, the weight of each factor derived from the best prediction model was applied to the entire study area to produce landslide susceptibility maps.

    Results show that slope gradient has the highest weight for landslide susceptibility mapping for both RIL and EIL. The RIL model built with four different factors (slope gradient, elevation, slope height and distance to the stream shows the best success rate of 93%; the EIL model built with five different factors (slope gradient, elevation, slope height, distance to the stream and distance to the fault has the best success rate of 98%. Furthermore, the EIL data was used to verify the RIL model and the success rate is 92%; the RIL data was used to verify the EIL model and the success rate is 53%.

  1. Giant Controllable Magnetization Changes Induced by Structural Phase Transitions in a Metamagnetic Artificial Multiferroic

    Bennett, S. P.; Wong, A. T.; Glavic, A.; Herklotz, A.; Urban, C.; Valmianski, I.; Biegalski, M. D.; Christen, H. M.; Ward, T. Z.; Lauter, V.

    2016-03-01

    The realization of a controllable metamagnetic transition from AFM to FM ordering would open the door to a plethora of new spintronics based devices that, rather than reorienting spins in a ferromagnet, harness direct control of a materials intrinsic magnetic ordering. In this study FeRh films with drastically reduced transition temperatures and a large magneto-thermal hysteresis were produced for magnetocaloric and spintronics applications. Remarkably, giant controllable magnetization changes (measured to be as high has ~25%) are realized by manipulating the strain transfer from the external lattice when subjected to two structural phase transitions of BaTiO3 (001) single crystal substrate. These magnetization changes are the largest seen to date to be controllably induced in the FeRh system. Using polarized neutron reflectometry we reveal how just a slight in plane surface strain change at ~290C results in a massive magnetic transformation in the bottom half of the film clearly demonstrating a strong lattice-spin coupling in FeRh. By means of these substrate induced strain changes we show a way to reproducibly explore the effects of temperature and strain on the relative stabilities of the FM and AFM phases in multi-domain metamagnetic systems. This study also demonstrates for the first time the depth dependent nature of a controllable magnetic order using strain in an artificial multiferroic heterostructure.

  2. Giant Controllable Magnetization Changes Induced by Structural Phase Transitions in a Metamagnetic Artificial Multiferroic

    Bennett, S. P.; Wong, A. T.; Glavic, A.; Herklotz, A.; Urban, C.; Valmianski, I.; Biegalski, M. D.; Christen, H. M.; Ward, T. Z.; Lauter, V.

    2016-01-01

    The realization of a controllable metamagnetic transition from AFM to FM ordering would open the door to a plethora of new spintronics based devices that, rather than reorienting spins in a ferromagnet, harness direct control of a materials intrinsic magnetic ordering. In this study FeRh films with drastically reduced transition temperatures and a large magneto-thermal hysteresis were produced for magnetocaloric and spintronics applications. Remarkably, giant controllable magnetization changes (measured to be as high has ~25%) are realized by manipulating the strain transfer from the external lattice when subjected to two structural phase transitions of BaTiO3 (001) single crystal substrate. These magnetization changes are the largest seen to date to be controllably induced in the FeRh system. Using polarized neutron reflectometry we reveal how just a slight in plane surface strain change at ~290C results in a massive magnetic transformation in the bottom half of the film clearly demonstrating a strong lattice-spin coupling in FeRh. By means of these substrate induced strain changes we show a way to reproducibly explore the effects of temperature and strain on the relative stabilities of the FM and AFM phases in multi-domain metamagnetic systems. This study also demonstrates for the first time the depth dependent nature of a controllable magnetic order using strain in an artificial multiferroic heterostructure. PMID:26940159

  3. Influence of ion bombardment induced patterning of exchange bias in pinned artificial ferrimagnets on the interlayer exchange coupling

    Artificial ferrimagnets have many applications as, e.g., pinned reference electrodes in magnetic tunnel junctions. It is known that the application of ion bombardment (IB) induced patterning of the exchange bias coupling of a single layer reference electrode in magnetic tunnel junctions with He ions is possible. For applications as, e.g., special types of magnetic logic, a combination of the IB induced patterning of the exchange bias coupling and the implementation of an artificial ferrimagnet as reference electrode is desirable. Here, investigations for a pinned artificial ferrimagnet with a Ru interlayer, which is frequently used in magnetic tunnel junctions, are presented. It is shown that in this kind of samples the exchange bias can be increased or rotated by IB induced magnetic patterning with 10 keV He ions without a destruction of the antiferromagnetic interlayer exchange coupling. An IrMn/Py/Co/Cu/Co stack turned out to be more sensitive to the influence of IB than the Ru based artificial ferrimagnet

  4. The use of an experimental device for the determination of the concentration of artificial radioactive aerosols at high altitudes

    By means of measurements with a Geiger counter on january, the 27th, in 1959 at an altitude reaching 65 km approximately, and following comparison with similar measurements made by Gangnes, Jenkins and Van Allen in 1949 at the same geomagnetic latitude (41 deg. North), it is concluded that radioactive aerosols above Southern France tropopause had a concentration less than 100.10-12 curies/m3 at that time. The missile used for this purpose and its performance are quickly described in this paper. (author)

  5. Reaction dynamics induced from light weakly-bound radioactive ion beams at near-barrier energies

    This work presents an overview of the latest experiments performed to study the reaction dynamics induced from light weakly-bound Radioactive Ion Beams on medium-mass and heavy targets at near-barrier energies. Production reactions, secondary beam intensities and experimental results on elastic scattering, transfer, breakup and fusion processes are presented and discussed. A comparative analysis of fusion and reaction cross section data for different projectile-target combinations is finally given. (author)

  6. Radioactivity induced in air and concrete shielding in the JAERI electron linac

    The secondary radiation activates the high-energy accelerator facilities, air, cooling water and building structures and surrounding soils. The induced radioactive materials become sources for public exposures. In addition, these will produce radioactive wastes in its decommissioning. Estimations of radiation exposures and its protections for the induced radioactive nuclei will be key issues for constructions of large-scale accelerators and its operations in future. This paper describes the investigation on compositions and spatial distributions of induced radioactive nuclei produced in the electron linear accelerator of JAERI, Tokai. The electron linear accelerator has the history of 33 years and the final specification of the accelerating energy of 120 MeV, the peak current of 500 mA, the pulse widths from 0.02 to 2 ?s and the repetition rates from 10 to 600 pps. We measured 11C, 13N and 15O by using the plastic scintillation counters, ionizing chambers, and radio-gas-chromatography. Ratios of the saturated activities of 13N and 15N as a function of the angle from the beam axis were obtained. Time-dependent chemical compositions of 13N and 15N up to the irradiation time 60 min was also estimated using the electromagnetic cascade code. We made core-borings of 4.5 cm in diameter and 150 cm in depth on the shielding concrete. Gamma rays counting rates as a function of the depth of concrete was obtained on the samples. Furthermore, the concentrations of gamma-rays emitters were identified. These results indicate that the spatial dependence is very important in relation with the un-isotropic propagation of the beam particles. Much more accumulations of this type of data are necessary to elucidate behaviors of induced radio nuclei. (Tanaka, T.)

  7. Time and energy resolved runaway measurements in TFR from induced radioactivity

    A time and energy resolved measurement of the radioactivity induced by runaway electrons in proper samples has been developped in TFR. The data give an information on the confinement time of these electrons, which appears to be strongly dependent on the toroidal field, suggesting the onset of a magnetic turbulence at lower fields. Observations showing that the runaway electrons deeply penetrate into the limiter shadow are also reported

  8. Alternatives of applications in the information taking with artificial radioactive tools in the mature fields of the South region

    In this work it is widely described the application of the saturation control tool (RST) used in the campo Rodador (Mexico), and shortly the registration tools of location monitoring (RMT) and the Monitor tool of the location operation (RPM) used for the evaluation in site of the mature wells, had being at the present time these three tools with nuclear reaction mechanisms to obtain the water saturation and of hydrocarbon by means of the Neutron capture (PNC) and Inelastic scattering (IS). Both tools have been designed to help to the evaluation of the mature wells in the locations. Starting from measurements made through the lining pipe applying nuclear techniques used by these tools of registrations to derive the water saturation and of hydrocarbon. In this work the basic principles of radioactivity and their application in the radioactive tools are described as well as the operative aspects of the tools before mentioned, some practical applications of the saturation control tool are presented and a technical study of cost-benefit and it is shown as the technology advances have allowed to carry out considerable progresses in the taking of information of the mature wells helping by this way, to build better geological models in the locations that help to increase the hydrocarbon production in wells that have many years of exploitation. (Author)

  9. An artificial neural network approach to laser-induced breakdown spectroscopy quantitative analysis

    The usual approach to laser-induced breakdown spectroscopy (LIBS) quantitative analysis is based on the use of calibration curves, suitably built using appropriate reference standards. More recently, statistical methods relying on the principles of artificial neural networks (ANN) are increasingly used. However, ANN analysis is often used as a ‘black box’ system and the peculiarities of the LIBS spectra are not exploited fully. An a priori exploration of the raw data contained in the LIBS spectra, carried out by a neural network to learn what are the significant areas of the spectrum to be used for a subsequent neural network delegated to the calibration, is able to throw light upon important information initially unknown, although already contained within the spectrum. This communication will demonstrate that an approach based on neural networks specially taylored for dealing with LIBS spectra would provide a viable, fast and robust method for LIBS quantitative analysis. This would allow the use of a relatively limited number of reference samples for the training of the network, with respect to the current approaches, and provide a fully automatizable approach for the analysis of a large number of samples. - Highlights: • A methodological approach to neural network analysis of LIBS spectra is proposed. • The architecture of the network and the number of inputs are optimized. • The method is tested on bronze samples already analyzed using a calibration-free LIBS approach. • The results are validated, compared and discussed

  10. An artificial neural network approach to laser-induced breakdown spectroscopy quantitative analysis

    D'Andrea, Eleonora; Pagnotta, Stefano; Grifoni, Emanuela; Lorenzetti, Giulia; Legnaioli, Stefano; Palleschi, Vincenzo; Lazzerini, Beatrice

    2014-09-01

    The usual approach to laser-induced breakdown spectroscopy (LIBS) quantitative analysis is based on the use of calibration curves, suitably built using appropriate reference standards. More recently, statistical methods relying on the principles of artificial neural networks (ANN) are increasingly used. However, ANN analysis is often used as a black box system and the peculiarities of the LIBS spectra are not exploited fully. An a priori exploration of the raw data contained in the LIBS spectra, carried out by a neural network to learn what are the significant areas of the spectrum to be used for a subsequent neural network delegated to the calibration, is able to throw light upon important information initially unknown, although already contained within the spectrum. This communication will demonstrate that an approach based on neural networks specially taylored for dealing with LIBS spectra would provide a viable, fast and robust method for LIBS quantitative analysis. This would allow the use of a relatively limited number of reference samples for the training of the network, with respect to the current approaches, and provide a fully automatizable approach for the analysis of a large number of samples.

  11. The extreme Rhone River flood of December 2003 (south east France) - Consequences on the translocation of artificial radioactive contaminants onto the flooded areas

    Full text: In recent years, great progress has been made in reducing the direct emission of artificial radioactivity and other contaminants into the environment from industrial sources. However the transport and fate of previously-released pollutants is still of great concern. In particular, it is now recognized that certain natural sinks, such as soils and deposits of sediment in streams, rivers and oceans, can entrain the contaminants for long periods of time, only to serve as sources of contamination at some later date. Such a phenomenon was first observed in the Irish Sea after sharp decreases in releases from the spent fuel reprocessing plant in Sellafield. In rivers, one of the primary mechanisms for the remobilization of contaminated deposits is thought to be major flood events. As a result of climate change, floods have become more abundant and more destructive in many regions of the globe including Europe. Then substantial changes in risk of translocation of sediments and associated contaminants onto flooded areas is expected. At the beginning of December 2003 an exceptional meteo climatic event led to an extreme Rhone River flood that flooded almost 500 km2 of the low Rhone valley. Flooding waters entrained a large amount of sediments that have deposited on agricultural soils and urban areas. Therefore particle reactive contaminants such as radionuclides may have been partly translocated from the River onto a large terrestrial area through remobilisation of contaminated fluvial sediments. The soils of the low Rhone valley are labelled with 2000 Bq m-2 for 137Cs, 50 Bq m-2 for 239+240Pu and 1.5 Bq m-2 for 238Pu as mean values. Based on our previous studies we estimate than radioactive inputs onto flooded areas might reach about 500 Bq m-2 for 137Cs. Nevertheless, a great spatial heterogeneity is expected depending on both the mass and nature of the sedimentary deposits. Several field cruises were performed until February 2004 to estimate the spatial spreading of sedimentary deposits. The deposit thinness were measured at almost 140 reference points within 3 main flooded areas whom one includes the Arles city. 87 samples were collected and are analysed for their sedimentary nature and organic matter content. About fifty percent of these samples are analysed regarding artificial radionuclides (gamma-emitters), organic contaminants and trace metals. Finally, a map of additional contamination of flooded areas during December 2003 is expected together with an evaluation of the consequences of such extreme flood events. (author)

  12. The extreme Rhone River flood of December 2003 (South East France) - Consequences on the translocation of artificial radioactive contaminants onto the flooded areas

    Full text: In recent years, great progress has been made in reducing the direct emission of artificial radioactivity and other contaminants into the environment from industrial sources. However the transport and fate of previously-released pollutants is still of great concern. In particular, it is now recognized that certain natural sinks, such as soils and deposits of sediment in streams, rivers and oceans, can entrain the contaminants for long periods of time, only to serve as sources of contamination at some later date. Such a phenomenon was first observed in the Irish Sea after sharp decreases in releases from the spent fuel reprocessing plant in Sellafield. In rivers, one of the primary mechanisms for the remobilization of contaminated deposits is thought to be major flood events. As a result of climate change, floods have become more abundant and more destructive in many regions of the globe including Europe. Then substantial changes in risk of translocation of sediments and associated contaminants onto flooded areas is expected. At the beginning of December 2003 an exceptional meteo climatic event led to an extreme Rhone River flood that flooded almost 500 km2 of the low Rhone valley. Flooding waters entrained a large amount of sediments that have deposited on agricultural soils and urban areas. Therefore particle reactive contaminants such as radionuclides may have been partly translocated from the River onto a large terrestrial area through remobilisation of contaminated fluvial sediments. The soils of the low Rhone valley are labelled with 2000 Bq m-2 for 137Cs, 50 Bq m-2 for 239+240Pu and 1.5 Bq m-2 for 238Pu as mean values. Based on our previous studies we estimate than radioactive inputs onto flooded areas might reach about 500 Bq m-2 for 137Cs. Nevertheless, a great spatial heterogeneity is expected depending on both the mass and nature of the sedimentary deposits. Several field cruises were performed until February 2004 to estimate the spatial spreading of sedimentary deposits. The deposit thinness were measured at almost 140 reference points within 3 main flooded areas whom one includes the Arles city. 87 samples were collected and are analysed for their sedimentary nature and organic matter content. About fifty percent of these samples are analysed regarding artificial radionuclides (gamma-emitters), organic contaminants and trace metals. Finally, a map of additional contamination of flooded areas during December 2003 is expected together with an evaluation of the consequences of such extreme flood events. (author)

  13. Plant height reduction in populations of triticale (X triticosecale Wittmack by induced mutations and artificial crosses

    Fábio Pandini

    1997-09-01

    Full Text Available Induced mutations by gamma radiation (0, 5, 10, 20 and 40 kR doses and reciprocal crosses were tested as mechanisms of enhancing genetic variability for plant height in two triticale cultivars, BR4 and EMBRAPA18. The reciprocal crosses and all doses of radiation showed similar increase in genetic amplitude for this trait, being suitable for increasing variability in breeding programs. Genotypes showed different responses as the gamma ray doses were increased, expressing shorter plant height. The decision of using induced mutations or artificial crosses depends on the resources available and the selection method to be usedMutações induzidas pelo uso das doses de radiação gama 0, 5, 10, 20 e 40 kR e cruzamentos artificiais recíprocos foram testados como mecanismos para aumentar a variabilidade genética em duas cultivares de triticale, BR4 e EMBRAPA18. Os tratamentos empregados provocaram amplitudes similares de variabilidade genética, com alterações nas médias e variâncias, podendo favorecer o emprego da seleção na obtenção de genótipos superiores. As respostas dos genótipos foram diferenciadas, sendo mais acentuadas quando submetidos a doses superiores do tratamento mutagênico, determinando uma redução na estatura. Em relação ao nível de variabilidade genética obtida, os tratamentos mutagênicos foram tão eficientes quanto as hibridações artificiais. A decisão do método a ser utilizado deve ser adequada aos recursos disponíveis, assim como o mecanismo mais eficiente de seleção para os caracteres de interesse

  14. DCHAIN-SP 2001: High energy particle induced radioactivity calculation code

    For the purpose of contribution to safety design calculations for induced radioactivities in the JAERI/KEK high-intensity proton accelerator project facilities, the DCHAIN-SP which calculates the high energy particle induced radioactivity has been updated to DCHAIN-SP 2001. The following three items were improved: (1) Fission yield data are included to apply the code to experimental facility design for nuclear transmutation of long-lived radioactive waste where fissionable materials are treated. (2) Activation cross section data below 20 MeV are revised. In particular, attentions are paid to cross section data of materials which have close relation to the facilities, i.e., mercury, lead and bismuth, and to tritium production cross sections which are important in terms of safety of the facilities. (3) User-interface for input/output data is sophisticated to perform calculations more efficiently than that in the previous version. Information needed for use of the code is attached in Appendices; the DCHAIN-SP 2001 manual, the procedures of installation and execution of DCHAIN-SP, and sample problems. (author)

  15. [Induced radioactivity in irradiated foods by X ray or gamma ray].

    Miyahara, Makoto

    2007-01-01

    In the course of the archival studies on safety of irradiated foods by the US Army, experimental records conducted by Glass & Smith, and Kruger & Wilson were investigated, based on our experimental experience. Food irradiation by Co-60 or 4 approximately 24MeV X ray can induce small amount of radioactivity in the foods. The principal mechanisms of the nuclear reactions are (gamma, n). The resulting nuclear products found in irradiated target solutions were Ba-135m, Pb-204m, Hg-199m, Ag-107m,Ag-109m, Cd-111m,Cd-113m, Sn-117m, Sn-119m, Sr-87m, Nb-93m, In113m, In-115m, Te-123m, Te-125m, Lu-178m Hf-160m by the (gamma, n) reaction. The total radio-activities in beef, bacon, shrimp, chicken, and green beans were counted at 60 days after irradiation by Cs-137, Co-60, and fuel element. The activities more than background were found in irradiated bacon and beef by Co-60. and activities were found in most foods when foods were irradiated by high energy X ray and the fuel element. The results were understood as the neutron activation by (gamma, n) or (n, gamma) reaction. Therefore, high energy X ray and spent fuel element were not used for food irradiation. As the results of this study Co-60 has been used with small amount of induced radioactivity in food. PMID:18220055

  16. DCHAIN-SP 2001: High energy particle induced radioactivity calculation code

    Kai, Tetsuya; Maekawa, Fujio; Kasugai, Yoshimi; Takada, Hiroshi; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kosako, Kazuaki [Sumitomo Atomic Energy Industries, Ltd., Tokyo (Japan)

    2001-03-01

    For the purpose of contribution to safety design calculations for induced radioactivities in the JAERI/KEK high-intensity proton accelerator project facilities, the DCHAIN-SP which calculates the high energy particle induced radioactivity has been updated to DCHAIN-SP 2001. The following three items were improved: (1) Fission yield data are included to apply the code to experimental facility design for nuclear transmutation of long-lived radioactive waste where fissionable materials are treated. (2) Activation cross section data below 20 MeV are revised. In particular, attentions are paid to cross section data of materials which have close relation to the facilities, i.e., mercury, lead and bismuth, and to tritium production cross sections which are important in terms of safety of the facilities. (3) User-interface for input/output data is sophisticated to perform calculations more efficiently than that in the previous version. Information needed for use of the code is attached in Appendices; the DCHAIN-SP 2001 manual, the procedures of installation and execution of DCHAIN-SP, and sample problems. (author)

  17. Artificial abelian gauge potentials induced by dipole-dipole interactions between Rydberg atoms

    Cesa, A

    2013-01-01

    We analyze the influence of dipole-dipole interactions between Rydberg atoms on the generation of abelian artificial gauge potentials and fields. When two Rydberg atoms are driven by a uniform laser field, we show that the combined atom-atom and atom-field interactions give rise to new, non-uniform, artificial gauge potentials. We identify the mechanism responsible for the emergence of these gauge potentials. Analytical expressions for the latter indicate that the strongest artificial magnetic fields are reached in the regime intermediate between the dipole blockade regime and the regime in which the atoms are sufficiently far apart such that atom-light interaction dominates over atom-atom interactions. We discuss the differences and similarities of artificial gauge fields originating from resonant dipole-dipole and van der Waals interactions. We also give an estimation of experimentally attainable artificial magnetic fields resulting from this mechanism.

  18. Induced radioactivities and cross section measurements of the 14 MeV irradiated molybdenum foils

    The radioactivities of 14 MeV neutron irradiated Molybdenum foils have been measured for comparison exercise conducted by the IAEA Nuclear Data Section. The spectra of the characteristic gamma-rays emitted as a result of the induced radioactivity were taken with a Ge(Li) detector and an Intrinsic Germanium detector. The cross sections for the reaction 92Mo(n,np)91mNb, 95Mo(n,p)95Nb and 98Mo(n,α)95Zr have been determined using the information provided by the IAEA on the irradiation time, total fluence and masses of the irradiated foils. The activation cross sections determined from the present measurements have been compared with previous work. (author). 8 refs, figs, 3 tabs

  19. Artificial radioactivity in the lower Rhone river. Consequences of floods on activity levels and flow toward the mediterranean

    Despite analytical strategies that today measure ultra-trace levels (i.e., -5 Bq.L-1) of artificial radionuclides, gamma spectrometry of Rhone River samples taken downstream from the nuclear installations located along the Rhone valley regularly detects only 137Cs, 60Co and 241Am. Since dismantlement of the Marcoule-COGEMA reprocessing plant began in 1997, lists of radionuclides in its effluent include 51Cr, 54Mn, 63Ni, 110mAg and 65Zn, released however at levels 10 to 1,000-fold lower than those of 137Cs or 60Co. Today Marcoule effluent is no longer the principal source of 137Cs in the Rhone River basin, as it was in the 1990's. Significant quantities of 137Cs now come from the Rhone watershed itself, from the drainage of soils exposed to atmospheric fallout from the past nuclear tests and from the accident at Chernobyl, and second, from remobilization of previously formed sediment. Our recent research shows that flood events may generate an increase of more than two orders of magnitude in 137Cs activity in downstream Rhone water, because of the input of contaminated particles from both watershed erosion and sediment remobilization. Flood events also generate the flow of high levels of particulate and associated contaminants towards the Mediterranean Sea. Of the 17322 GBq of 137Cs transferred from the Rhone to the Mediterranean from August 2002 through August 2003, 1119 GBq went during two floods in September and November 2002: 60% of the annual transfer took place in only 15 days and included almost ten times as much 137Cs activity as is released annually by the reprocessing plant today. The contribution to these flows of re-mobilized Rhone basin sediment inventories contaminated over the past 40 years is under study today. (authors)

  20. Artificial radioelements

    This catalogs retails the list of the artificial radioelements obtained at the Zoe reactor. A certain number of methods of concentration and separation has been finalized. The targets are submitted to irradiation in a thermal neutron flux in order to get by neutron reaction the wanted radioelements. In the case of the reaction (n,p), the radioactive element separated chemically in order to produce some radioelements 'without trainer'. For the radioelements obtained from the reaction (n, γ) one uses the effect of Szilard and Chalmers to separate the active and inactive atoms in order to increase the specific activity of the radioelement of interest. (M.B.)

  1. Selection and investigation of sites for the disposal of radioactive wastes in hydraulically induced subsurface fractures

    Injection of intermediate-level radioactive wastes (specific activity of less than 6 x 103 ?Ci/mL, consisting mainly of radionuclides, such as strontium and cesium, having half-lives of less than 50 years) mixed with cement into a thick shale formation is a promising and feasible disposal method. Hydraulic fracturing provides openings in the shale to accommodate the wastes. Ion exchange and radionuclide-adsorption materials can be added to the grout during mixing to further increase the radionuclide-retaining capacity of the grout. After solidification of the grout, the injected wastes become an integral part of the shale formation, and therefore the wastes will remain at depth and in place as long as the injection zone is not subjected to erosion and dissolution. Problems concerning safety of the disposal method are (1) the potential for inducing vertical fractures, (2) phase separation during and after the injections, (3) the reliability of methods for determining the orientation of induced fractures, (4) the possibility of triggering earthquakes, and (5) radionuclides being leached and transported by ground water. Theoretical considerations about inducing nearly horizontal bedding-plane fractures in shale are discussed, as are field procedures for site selection, safety, and the monitoring and operation of radioactive waste disposal. Case histories are used as examples to demonstrate the application of the theory and techniques of field operations

  2. Selection and investigation of sites for the disposal of radioactive wastes in hydraulically induced subsurface fractures

    Injection of intermediate-level radioactive wastes (specific activity of less than 6 x 103?Ci/mL, consisting mainly of radionuclides, such as strontium and cesium, having half-lives of less than 50 years) mixed with cement into a thick shale formation is a promising and feasible disposal method. Hydraulic fracturing provides openings in the shale to accommodate the wastes. Ion exchange and radionuclide-adsorption materials can be added to the grout during mixing to further increase the radionuclide-retaining capacity of the grout. After solidification of the grout, the injected wastes become an integral part of the shale formation, and therefore the wastes will remain at depth and in place as long as the injection zone is not subjected to erosion or dissolution. Problems concerning safety of the disposal method are: (1) the potential for inducing vertical fractures, (2) phase separation during and after the injections, (3) the reliability of methods for determining the orientation of induced fractures, (4) the possibility of triggering earthquakes, and (5) radionuclides being leached and transported by ground water. Theoretical considerations about inducing nearly horizontal bedding-plane fractures in shale are discussed, as are field procedures for site selection, safety, and the monitoring and operation of radioactive waste disposal. Case histories are used as examples to demonstrate the application of the theory and techniques of field operations

  3. Site selection and investigation for subsurface disposal of radioactive wastes in hydraulically induced fractures

    Injection into a thick shale formation of intermediate-level radioactive wastes (specific activity of less than 6 x 103 μCi/ml consisting mainly of radionuclides such as strontium and cesium with half-lives of less than 50 years) mixed with cement is a promising and feasible disposal method. Hydraulic fracturing provides openings in the shale to accommodate the wastes. Ion exchange and radionuclide adsorption materials can be added to the grout during mixing to further increase the radionuclide retaining capacity of the grout. After solidification of the grout, the injected wastes become an integral part of the shale formation and thus the wastes will remain at depth and in place as long as the injection zone is not subjected to erosion or dissolution. Problems concerning safety of the disposal method are: (1) potential of inducing vertical fractures; (2) phase separation during and after injections; (3) reliability of methods for determining orientation of induced fractures; (4) possibility of triggering earthquakes; and (5) radionuclides leaching and transporting by ground water. Waste injections are made in multiple-layer injection stages in an injection well. After the first series of injections are made at the greatest depth, the well is plugged by cement at the injection depth. The depth of the second series of injections is located at a suitable distance above the first injection depth. The repeated use of the injection well distributes the cost of construction of injection and monitoring wells over many injections, thereby making hydraulic fracturing and grout injection economically attractive as a method for disposal of radioactive wastes. Theoretical considerations of inducing nearly horizontal bedding-plane fractures in shale and field procedures for site selection, safety, monitoring and operation of radioactive waste disposal are discussed. Case histories are used as examples to demonstrate the theoretical applications and field operations

  4. High energy proton-induced radioactivity in HgI2 crystals

    Mercuric iodide (HgI2) semiconductor crystals are generating a lot of interest as room temperature solid state detectors for hard X-ray astronomy observations. For these applications one of the most important background sources is the cosmic proton induced radioactivity in the detector material. In order to study this background noise contribution a 1x1x1 cm HgI2 crystal was irradiated with high energy protons. The resulting long-lived unstable isotopes and their production rates have been identified and compared with Monte Carlo simulations. ((orig.))

  5. High energy proton-induced radioactivity in HgI{sub 2} crystals

    Porras, E. [Valencia Univ. (Spain). Dept. Mat. Aplicada y Astronomia; Carter, T. [Southampton Univ. (United Kingdom). Dept. of Physics; Perez, J.M. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain); Ferrero, J.L. [Instituto de Fisica Corpuscular, Valencia (Spain); Sanchez, F. [Instituto de Fisica Corpuscular, Valencia (Spain); Ruiz, J.A. [Navarra Universidad Publica (Spain). Dept. de Fisica; Schutz, Y. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Lei, F. [Southampton Univ. (United Kingdom). Dept. of Physics; Dean, A.J. [Southampton Univ. (United Kingdom). Dept. of Physics; Reglero, V. [Valencia Univ. (Spain). Dept. Mat. Aplicada y Astronomia; Olmos, P. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain)

    1995-03-15

    Mercuric iodide (HgI{sub 2}) semiconductor crystals are generating a lot of interest as room temperature solid state detectors for hard X-ray astronomy observations. For these applications one of the most important background sources is the cosmic proton induced radioactivity in the detector material. In order to study this background noise contribution a 1x1x1 cm HgI{sub 2} crystal was irradiated with high energy protons. The resulting long-lived unstable isotopes and their production rates have been identified and compared with Monte Carlo simulations. ((orig.)).

  6. Dependence of Characteristics of SURA Induced Artificial ULF/VLF Signals on Geomagnetic Activity

    Kotik, D. S.; Ryabov, A. V.; Ermakova, E. N.; Pershin, A. V.

    2015-10-01

    A comprehensive study of artificial ionospheric signal generation in the ULF/VLF bands at SURA facility in Russia was conducted during the past 4 years. We investigated the influence of geomagnetic activity on the characteristics of artificial low-frequency signals under the background of increasing solar activity. No correlation of artificial ULF signals with variations of Earth's magnetic field was observed for weak geomagnetic disturbances (Kp ? 3) while the VLF signals increased in the growth phase of the geomagnetic perturbation. In case of strong magnetic storm (Kp ? 5+) a tendency of the amplitude of the ULF/VLF signals decrease with increasing magnetic disturbance was observed. Sometimes, the modulation of artificial ULF signals with a period of 15-30 s was detected in the decay phase of magnetic storms. During storm time, a change in the polarization of artificial VLF emissions was detected. The right polarization becomes predominant. Interpretation of observed peculiarities of artificial VLF signals is given in the context of the physical mechanism of ionospheric current drive by RF pumping.

  7. Measurement of fertilizers induced radioactivity in tobacco plants and elemental analysis using ICAP–AES

    It is widely accepted that tobacco smoke is the leading cause of lung cancer worldwide. The alpha radioactive content present in tobacco smoke and increasing number of lung cancer cases explain the importance of investigation. The use of different fertilizers may cause alteration in the metabolism of plants causing different response towards uptake of different element and radionuclides. In the present study, the estimation of alpha radioactivity induced by use of different fertilizers in tobacco leaves was made using solid state nuclear track detector (LR-115) to identify the relative presence of radionuclides in the plants. The radon exhalation rates from the tobacco plant were carried out to confirm the presence of radium or emission of radon from plant. The elemental analysis of tobacco plant by inductively coupled argon plasma atomic emission spectrometry provides a way to understand the difference occurred in metabolism caused by the use of fertilizers. The alpha track densities were found to vary with nature of fertilizers added to the soil and an increase was also observed with time. The radon mass exhalation rates in various tobacco plants were found to vary with type of fertilizers used. - Highlights: • The study is related to alpha radioactivity measurements in tobacco plants. • The radon mass exhalation rates in various tobacco plants were also measured. • Study is related to analysis of chemical elements in different fertilized tobacco samples

  8. Calculation of radioactivity induced in gamma-ray spectrometers during spaceflight

    Radioactivity induced in detector materials by cosmic rays, trapped protons and secondary neutrons is a major source of background in gamma-ray astronomy and remote sensing spectroscopy of the moon and the planets. A calculation scheme for assessing this component has been developed based on semi-empirical cross-sections and stochastic calculations of energy-loss spectra of radioactive nuclides. In addition, predictive methods are available based on experimental data obtained from monoenergetic proton beam irradiations of scintillators at energies of 155, 600, 800 MeV and 6 GeV. Application of these methods to in-flight results from scintillator detectors carried on lightweight OSO spacecraft, for which trapped protons of 20-200 MeV dominate, shows that the induced radiactivity at lower photon energies can be well explained by spallation interactions of primary protons in the central crystal detector elements. The contributions to the induced activity due to collimators, materials surrounding the detector, and the spacecraft become increasingly important at higher proton energies. For such detectors carried on the Apollo missions, the more energetic (> 300 MeV) cosmic-ray flux dominates. The library of isotopes presently used can predict only about half the induced radiactivity, and corrections for missing radionuclides must be based on the experimental irradiation results. Results from crystals returned to Earth from Apollo 17 and Apollo-Soyuz show that, for heavy spacecraft, secondary neutrons can significantly enchance the background. Preliminary estimates have been made of the important gamma-ray line features to be expected from cosmic-ray and trapped proton induced spallation products in germanium detectors. (orig.)

  9. Evidences of possible reservoir-induced seismicity by the Pertusillo artificial lake (Southern Italy): preliminary results and ongoing activities

    Giocoli, A.; Stabile, T.; Perrone, A.; Piscitelli, S.; Telesca, L.; Lapenna, V.

    2012-12-01

    Reservoir-induced seismicity by filling artificial lakes has been observed over the last 60 years in several regions of the Earth. The presence of water reservoirs in regions with high seismogenic potential, such as the Pertusillo artificial lake in Agri Valley (Southern Italy), can modify the occurrence of earthquakes and influence the seismic hazard of the area. In particular, the Pertusillo lake is a relatively large water reservoir with a capacity of 1.5x108 m3, maintained by a 95 m high concrete dam that was constructed in the Agri river from 1956 to 1962. In this study, we compare the reservoir filling history over the last 30 years with the correspondent spatio-temporal pattern of the observed small to moderate earthquakes (Ml ? 3.2), to interpret possible correlations that could point-out an induced seismicity by the Pertusillo artificial lake. Preliminary results are discussed and ongoing activities in the area of study are presented. This study is funded by the project "Study of the Local Seismicity" at the Val d'Agri Environmental Observatory (Southern Italy), under the agreement between the Basilicata Region and the Italian National Research Council - Institute of Methodologies for Environmental Analysis (CNR-IMAA).

  10. Cosmic-ray induced production of radioactive noble gases in the atmosphere, ground, and seawater

    This paper describes the development of an MCNP6 model and a suite of supporting MATLAB scripts being developed to conduct detailed studies of the radioactive noble gas background activity concentrations resulting from cosmic-neutron-induced reactions in the Earth's atmosphere, in various geologies, and in seawater. Initial results generated using the MCNP6 model and the suite of supporting MATLAB scripts indicate that the cosmic-neutron-induced 133Xe background activity concentrations at a depth of 1 m in a geology representative of the Earth's upper crust and a depth of 5 m in seawater are about 3.48 × 10-1 and 8.49 × 10-7 mBq m-3, respectively. (author)

  11. Investigation of induced radioactivity in the CERN Large Electron Positron collider for its decommissioning

    Silari, Marco

    2004-01-01

    The future installation of the Large Hadron Collider in the tunnel formerly housing the Large Electron Positron collider (LEP) required the dismantling of the latter after 11-year operation. As required by the French legislation, an extensive theoretical study was conducted before decommissioning to establish the possible activation paths both in the accelerator and in the four experiments (L3, ALEPH, OPAL and DELPHI) installed around the ring. The aim was to define which areas may contain activated material and which ones would be completely free of activation. The four major sources of activation in LEP, i.e., distributed and localized beam losses, synchrotron radiation and the super-conducting RF cavities, were investigated. Conversion coefficients from unit lost beam power to induced specific activity were established for a number of materials. A similar study was conducted for the four experiments, evaluating the four potential sources of induced radioactivity, namely e**+e **- annihilation events, two-p...

  12. Radioactivity Assessment of Natural and Artificial Radionuclides in Soil Samples from Tha Phae, La-ngu and Thung Wa Districts in Satun Province, Thailand

    Full text: Specific activities of natural (238U, 226Ra, 232Th and 40K) and artificial anthropogenic (137Cs) radionuclides in 65 soil samples collected from Tha Phae, La-ngu and Thung Wa Districts in Satun province have been measured and analyzed. Experimental results were obtained by using a high-purity germanium (HPGe) detector and gamma spectrometry analysis system. Experimental set-up and measurement were carried out at Nuclear and Material Physics Laboratory in Department of Physics Faculty of Science Thaksin University Songkhla Campus. The counting time for each sample was 10,800 seconds or 3 hours. It was found that the soil specific activities ranged from 0.00 to 11608.87 Bq/kg for 40K, 0.00 to 352.57 Bq/kg for 226Ra, 0.00 to 123.28 Bq/kg for 232Th and 0.00 to 16.28 Bq/kg for 137Cs with mean values of 3,248.96 ± 231.32 Bq/kg, 71.35 ± 5.97 Bq/kg, 53.59 ± 2.14 Bq/kg, and 0.68 ± 0.19 Bq/kg, respectively. Furthermore, the results were used to evaluate the absorbed dose rates in air (D), the radium equivalent (Raeq), the external hazard index (Hex) and the annual effective dose rate (AED) for this area. Moreover, the experimental results were compared to the previous data of the Office of Atoms for Peace (OAP). Thailand and global radioactivity measurements and evaluation, including the proposed recommended values the Organization for Economic Cooperation and Development (OECD, 1979) and the United Nations Scientific Committee on the Effects of Atomic Radiation

  13. Induced radioactivity analysis for the NSRL Linac in China using Monte Carlo simulations and gamma-spectroscopy

    He, Lijuan; Li, Weimin; Chen, Zhi; Chen, Yukai; Ren, Guangyi

    2014-01-01

    The 200-MeV electron linac of the National Synchrotron Radiation Laboratory (NSRL) located in Hefei is one of the earliest high-energy electron linear accelerators in China. The electrons are accelerated to 200 MeV by five acceleration tubes and are collimated by scrapers. The scraper aperture is smaller than the acceleration tube one, so some electrons hit the materials when passing through them. These lost electrons cause induced radioactivity mainly due to bremsstrahlung and photonuclear reaction. This paper describes a study of induced radioactivity for the NSRL Linac using FLUKA simulations and gamma-spectroscopy. The measurements showed that electrons were lost mainly at the scraper. So the induced radioactivity of the NSRL Linac is mainly produced here. The radionuclide types were simulated using the FLUKA Monte Carlo code and the results were compared against measurements made with a High Purity Germanium (HPGe) gamma spectrometer. The NSRL linac had been retired because of upgrading last year. The re...

  14. Radiation dose due to neutron-induced residual radioactivities by the atomic bombs in Hiroshima and Nagasaki

    Radiation dose at 1 m above the ground was estimated due to neutron-induced radioactivities by the atomic bombings in Hiroshima and Nagasaki. The dose rate at the hypocenter at 1 min after the bombing was 600 and 400 cGy h-1 in Hiroshima and Nagasaki, respectively, and rapidly decreased with the decay of the main induced radioactivities of relatively short half-lives: 28Al (2.24 min), 56Mn (2.58 h) and 24Na (15.0 h). The infinite cumulative dose after the bombing was 120 and 57 cGy at the hypocenter of Hiroshima and Nagasaki, respectively, and also sharply decreased with the distance from the hypocenter. Considering the results obtained so far, the people who entered into the area less than 1 km from the hypocenter up to 1 weak after the bombing could receive external dose over 1 cGy from neutron-induced radioactivities. (author)

  15. Characterization of uranium in bituminized radioactive waste drums by self-induced X-ray fluorescence

    This paper reports the experimental qualification of an original uranium characterization method based on fluorescence X rays induced by the spontaneous gamma emission of bituminized radioactive waste drums. The main 661.7 keV gamma ray following the 137Cs decay produces by Compton scattering in the bituminized matrix an intense photon continuum around 100 keV, i.e. in the uranium X-ray fluorescence region. 'Self-induced' X-rays produced without using an external source allow a quantitative assessment of uranium as 137Cs and uranium are homogeneously mixed and distributed in the bituminized matrix. The paper presents the experimental qualification of the method with real waste drums, showing a detection limit well below 1 kg of uranium in 20 min acquisitions while the usual gamma rays of 235U (185 keV) or 238U (1001 keV of 234mPa in the radioactive decay chain) are not detected. The relative uncertainty on the uranium mass assessed by self-induced X-ray fluorescence (SXRF) is about 50%, with a 95% confidence level, taking into account the correction of photon attenuation in the waste matrix. This last indeed contains high atomic numbers elements like uranium, but also barium, in quantities which are not known for each drum. Attenuation is estimated thanks to the peak-to-Compton ratio to limit the corresponding uncertainty. The SXRF uranium masses measured in the real drums are in good agreement with long gamma-ray spectroscopy measurements (1001 keV peak) or with radiochemical analyses. (authors)

  16. Does ozone enhance the remineralizing potential of nanohydroxyapatite on artificially demineralized enamel? A laser induced fluorescence study

    Srinivasan, Samuelraj; Prabhu, Vijendra; Chandra, Subhash; Koshy, Shalini; Acharya, Shashidhar; Mahato, Krishna K.

    2014-02-01

    The present era of minimal invasive dentistry emphasizes the early detection and remineralization of initial enamel caries. Ozone has been shown to reverse the initial demineralization before the integrity of the enamel surface is lost. Nano-hydroxyapatite is a proven remineralizing agent for early enamel caries. In the present study, the effect of ozone in enhancing the remineralizing potential of nano-hydroxyapatite on artificially demineralized enamel was investigated using laser induced fluorescence. Thirty five sound human premolars were collected from healthy subjects undergoing orthodontic treatment. Fluorescence was recorded by exciting the mesial surfaces using 325 nm He-Cd laser with 2 mW power. Tooth specimens were subjected to demineralization to create initial enamel caries. Following which the specimens were divided into three groups, i.e ozone (ozonated water for 2 min), without ozone and artificial saliva. Remineralization regimen was followed for 3 weeks. The fluorescence spectra of the specimens were recorded from all the three experimental groups at baseline, after demineralization and remineralization. The average spectrum for each experimental group was used for statistical analysis. Fluorescence intensities of Ozone treated specimens following remineralization were higher than that of artificial saliva, and this difference was found to be statistically significant (Prestorative cycle.

  17. Study of the radioactivity induced in air by a 15-MeV proton beam

    Radioactivity induced by a 15-MeV proton beam extracted into air was studied at the beam transport line of the 18-MeV cyclotron at the Bern University Hospital (Inselspital). The produced radioactivity was calculated and measured by means of proportional counters located at the main exhaust of the laboratory. These devices were designed for precise assessment of air contamination for radiation protection purposes. The main produced isotopes were 11C, 13N and 14O. Both measurements and calculations correspond to two different irradiation conditions. In the former, protons were allowed to travel for their full range in air. In the latter, they were stopped at the distance of 1.5 m by a beam dump. Radioactivity was measured continuously in the exhausted air starting from 2 min after the end of irradiation. For this reason, the short-lived 14O isotope gave a negligible contribution to the measured activity. Good agreement was found between the measurements and the calculations within the estimated uncertainties. Currents in the range of 120-370 nA were extracted in air for 10-30 s producing activities of 9-22 MBq of 11C and 13N. The total activities for 11C and 13N per beam current and irradiation time for the former and the latter irradiation conditions were measured to be (3.60 0.48)x 10-3 MBq (nA s)-1 and (2.89 0.37)x 10-3 MBq (nA s)-1, respectively (authors)

  18. Radiological considerations on multi-MW targets Part I Induced radioactivity

    Agosteo, S; Silari, M

    2005-01-01

    CERN is designing a Superconducting Proton Linac (SPL) to provide a 2.2GeV, 4MW proton beam to feed facilities like, for example, a future Neutrino Factory or a Neutrino SuperBeam. The material activation in such facilities is an important aspect that has to be taken into account at an early design stage. In particular, the choice of the target has consequences on the induced radioactivity and dose rates in the target itself and in its surroundings. In the present work, the radiological aspects of a stationary target made up of small tantalum pellets are compared to those of a free-surface jet of mercury. An estimation of the hadronic inelastic interactions and the production of residual nuclei in the target, the magnetic horn, the decay tunnel, the surrounding rock and a downstream dump were performed for both targets by the Monte Carlo hadronic cascade code FLUKA. The aim was to assess the dose equivalent rate to be expected during maintenance work and to evaluate the amount of residual radioactivity, which...

  19. Radioactive Ion Beam Production by Fast-Neutron-Induced Fission in Actinide Targets at EURISOL

    Herrera-Martínez, Adonai

    The European Isotope Separation On-Line Radioactive Ion Beam Facility (EURISOL) is set to be the 'next-generation' European Isotope Separation On-Line (ISOL) Radioactive Ion Beam (RIB) facility. It will extend and amplify current research on nuclear physics, nuclear astrophysics and fundamental interactions beyond the year 2010. In EURISOL, the production of high-intensity RIBs of specific neutron-rich isotopes is obtained by inducing fission in large-mass actinide targets. In our contribution, the use of uranium targets is shown to be advantageous to other materials, such as thorium. Therefore, in order to produce fissions in U-238 and reduce the plutonium inventory, a fast neutron energy spectrum is necessary. The large beam power required to achieve these RIB levels requires the use of a liquid proton-to-neutron converter. This article details the design parameters of the converter, with special attention to the coupled neutronics of the liquid converter and fission target. Calculations performed with the ...

  20. Assessing the Effectiveness of Risk Communication for Maintenance Workers Who Deal With Induced Radioactivity Management of Medical Linear Accelerators.

    Watanabe, Hiroshi; Maehara, Yoshiaki; Fujibuchi, Toshioh; Koizumi, Mitsue; Yamaguchi, Ichiro; Kida, Tetsuo; Ooyama, Masaya; Horitsugi, Genki; Hiraki, Hitoshi; Tsukamoto, Atsuko; Itami, Jyun

    2015-08-01

    In Japan, an amended law that mandates levels of unintended induced radioactivity has been in effect since 1 April 2012. According to the new regulation, if the concentration of induced radioactivity in affected parts is above the clearance level, the parts must be regarded as radioactive even if they weigh less than 1 kg. This regulation reform raises several new issues concerning medical linear accelerators, including how to determine the decay period for induced radioactivity before maintenance can be performed and how to identify what parts should be considered radioactive waste. The authors performed several risk communication (RC) activities aimed at improving the understanding of maintenance workers at medical accelerator manufacturers and establishing good guidelines by involving stakeholders. For this purpose, a working group was established and conducted RC activities, such as holding opinion exchange meetings between medical staff and maintenance workers and creating a booklet to answer questions from maintenance workers. To evaluate these activities, three questionnaire surveys were conducted between 2011 and 2014. According to the results of this study, the ratio of maintenance workers who accepted "The decay period is within one week" was approximately 60% at the third survey and significantly increased (P < 0.0001) during the survey period. Approximately 25% of the maintenance workers felt that not enough information was provided about the decay period, and approximately 63% thought that the information provided on the health effects of radiation was sufficient. These results suggest that the present RC was successful. PMID:26107435

  1. Giant Cross–Kerr Effect for Propagating Microwaves Induced by an Artificial Atom

    Hoi, Io-Chun; Frisk Kockum, Anton; Palomaki, Tauno; Stace, Thomas M.; Fan, Bixuan; Tornberg, Lars; Sathyamoorthy, Sankar Raman; Johansson, Göran; Delsing, Per; Wilson, Christopher

    2013-01-01

    We investigate the effective interaction between two microwave fields, mediated by a transmon-type superconducting artificial atom which is strongly coupled to a coplanar transmission line. The interaction between the fields and atom produces an effective cross–Kerr coupling. We demonstrate average cross–Kerr phase shifts of up to 20 degrees per photon with both coherent microwave fields at the single-photon level. Our results provide an important step toward quantum applications with propaga...

  2. Transposable Element-Induced Response to Artificial Selection in Drosophila Melanogaster: Molecular Analysis of Selection Lines

    Shrimpton, A. E.; Mackay, TFC.; Leigh-Brown, A. J.

    1990-01-01

    Artificial selection lines for abdominal bristle score of Drosophila melanogaster established from P-M hybrid dysgenic crosses showed increases in selection response, heritability and phenotypic variance compared to similar lines started from nondysgenic crosses. To determine whether this increased genetic variance could be due to enhanced transposition of P elements following the dysgenic cross, the cytological locations (sites) of P elements were determined by in situ hybridization for the ...

  3. The effect of radiation-induced free radicals on ion transport through artificial planar lipid membranes

    The study had the aim to elucidate the influence of free radicals on the function of various ion transport systems, which were built into artificial lipid membranes in planar arrangement. The radicals were obtained using ionising radiation (X-radiation and 14 MeV electrons). Their effects on ion transport were chiefly assessed by stationary conductivity measurements, a kinetic analysis on the basis of the charge-pulse technique was only performed for carrier-mediated ion transport. (orig.)

  4. A subcellular distribution of estrogen receptor-alpha is changed during artificially induced senescence of PC12 pheochromocytoma cells.

    Lee, Eunju; Mun, Ga Hee; Oh, Chang Seok; Chung, Yoon Hee; Cha, Choong Lk; Lee, Young Soo; Shin, Dong Hoon

    2004-11-30

    Although estrogen has been considered as a sex hormone for decades, recent reports suggest that estrogen might modulate the development and physiological function of the brain. In addition, the subcellular localization of estrogen receptors (ERs) has shown their presence within both the perinuclear cytoplasm and nuclei, suggesting that these ERs may differ functionally. We, therefore, assayed changes in the subcellular localization of ER-alpha immunoreactivity (IR) in rat pheochromocytoma PC12 cells during the artificial senescence induced by the telomerase inhibitor, 3'-azido-3'-deoxythymidine (AZT). After 2 months of culture with AZT, PC12 cells showed morphological and biochemical characteristics of cellular senescence. In the cells showing artificial senescence, the ER-alpha IR was mainly localized within the cytoplasm, whereas in control cells, ER-alpha IR was found only in the nuclei. Since senescence was induced by AZT, which inhibits the action of telomerase whenever the cells divide, the change in subcellular distribution of ER-alpha IR may be correlated with the length of the telomere. PMID:15531092

  5. Radioactive ion beams produced by neutron-induced fission at ISOLDE

    Catherall, R; Gilardoni, S S; Kster, U

    2003-01-01

    The production rates of neutron-rich fission products for the next-generation radioactive beam facility EURISOL are mainly limited by the maximum amount of power deposited by protons in the target. An alternative approach is to use neutron beams to induce fission in actinide targets. This has the advantage of reducing: the energy deposited by the proton beam in the target; contamination from neutron-deficient isobars that would be produced by spallation; and mechanical stress on the target. At ISOLDE CERN, tests have been made on standard ISOLDE actinide targets using fast neutron bunches produced by bombarding thick, high-Z metal converters with 1 and 1.4 GeV proton pulses. This paper reviews the first applications of converters used at ISOLDE. It highlights the different geometries and the techniques used to compare fission yields produced by the proton beam directly on the target with neutron-induced fission. Results from the six targets already tested, namely UC2/graphite and ThO2 targets with tungsten an...

  6. Prediction of Irradiation induced hardening by Artificial Neural Network for 304 and 316 stainless steels

    The internal structures of pressurized water reactors (PWR) located close to the reactor core are used to support the fuel assemblies, to maintain the alignment between assemblies and the control bars and to canalize the primary water. In general these internal structures consist of baffle plates in a solution annealed (SA) 304 stainless steel and baffle bolts in a cold worked (CW) 316 stainless steel. These components undergo a large neutron flux at temperatures between 280 and 380 .deg. C. As a result, the materials exhibit a substantial increase in yield stress and a reduction in ductility which may deteriorate the performance of a reactor operation. For instance the observed cracks in bolts, usually attributed to irradiation assisted stress corrosion cracking (IASCC). In this work, we tried to apply a artificial neural network (ANN) approach to a prediction of a IASCC of an austenitic stainless steels SA 304 and CW 316. We have predicted the yield stress in terms of a dislocation loops size and density. Besides, we compared experimental data with prediction data by an artificial neural network

  7. Snag characteristics and dynamics following natural and artificially induced mortality in a managed loblolly pine forest.

    Zarnoch, Stanley J. [USDA Forest Service; Vukovich, Mark A. [USDA Forest Service; Kilgo, John C. [USDA Forest Service; Blake, John I. [USDA Forest Service

    2013-06-10

    A 14-year study of snag characteristics was established in 41- to 44-year old loblolly pine (Pinus taeda L.) stands in southeastern USA. During the initial 5.5 years, no stand manipulation or unusually high-mortality events occurred. Afterwards, three treatments were applied consisting of trees thinned and removed, trees felled and not removed, and artificial creation of snags produced by girdling and herbicide injection. The thinned treatments were designed to maintain the same live canopy density as the snag-created treatment, disregarding snags that remained standing.We monitored snag height, diameter, density, volume, and bark percentage; the number of cavities was monitored in natural snags only. During the first 5.5 years, recruitment and loss rates were stable, resulting in a stable snag population. Large snags (≥25 cm diameter) were common, but subcanopy small snags (10 to <25 cm diameter) dominated numerically. Large natural snags survived (90% quantile) significantly longer (6.0–9.4 years) than smaller snags (4.4–6.9 years). Large artificial snags persisted the longest (11.8 years). Cavities in natural snags developed within 3 years following tree death. The mean number of cavities per snag was five times greater in large versus small snags and large snags were more likely to have multiple cavities, emphasizing the importance of mature pine stands for cavity-dependent wildlife species.

  8. Background studies: human-induced effects on the evolution of shallow land burial sites for radioactive waste disposal

    This report presents the results of a programme of background research on the human-induced effects on the long term evolution of shallow disposal sites for low level radioactive wastes. The work is intended to support development and use of the TIME2 simulation code. Within the context of climatic change up to the next glacial maximum three areas are addressed: planning and legislative control over site usage, biosphere state changes and intrusion. An appendix presents a discussion of some planning aspects of radioactive waste disposal. (author)

  9. Studies of ionising radiation induced bystander effects in 3D artificial tissue system and applications for radiation protection

    The universality of the target theory of radiation-induced effects is challenged by observations on non-targeted effects such as bystander effects. Essential features of non-targeted effects are that they do not require direct nuclear exposure by radiation and they are particularly significant at low doses. This new evidence suggests a need for a new paradigm in radiation biology. The new paradigm should cover both the classical (targeted) and the non-targeted effects. The bystander effect cannot be comprehensively explained on the basis of a single cell reaction. It is well known that an organism is composed of different cell types that interact as functional units in a way to maintain normal tissue function. Therefore the radiation response is not simply the sum of cellular responses as assumed in classical radiobiology, predominantly from studies using cell cultures. Experimental models, which maintain tissue-like intercellular cell signalling and 3D structure, are essential for proper understanding of the bystander effect. Our work relates to experimentation with novel 3D artificial human tissue systems available from MatTek Corporation (Boston, USA). Air-liquid interface culture technique is used to grow artificial tissues, which allow to model conditions present in vivo. The Gray Cancer Institute (Northwood, UK) charged particle microbeam was used to irradiate tissue samples in a known pattern with a known number of 3He2+ particles or protons. After irradiation, the tissues models were incubated for 3 days, fixed in 10 % NBF, paraffin embedded and then sliced into 5 μm histological sections located at varying distances from the plane of the irradiated cells. We studied in situ apoptosis and markers of differentiation. Significantly elevated bystander induced apoptosis was observed with 3'-OH DNA end-labelling based technique in 3D artificial tissue systems. Our results also suggested an importance of proliferation and differentiation status for bystander effect induction. A single 2 μm location on tissue section was pre-irradiated with 1-10 3He2+ particles (5 MeV; LET 75 keV/μm) using microbeam system. Even although only a single region of the tissue section was targeted, thousands of additional cells were found to undergo bystander induced differentiation. This resulted in an overall increase in the fraction of differentiated cells for approximately 10-15 %, which are much greater than that observed for the induction of damage (not more than 1-2 % of apoptotic cells). Our theory is that the main functions of bystander effect are to decrease the risk of transformation in a multi cultural organism exposed to radiation by removing a group of potentially damaged cells via apoptosis and increased differentiation. (author)

  10. Artificial granularity in two-dimensional arrays of nanodots fabricated by focused-electron-beam-induced deposition

    We have prepared 2D arrays of nanodots embedded in an insulating matrix by means of focused-electron-beam-induced deposition using the W(CO)6 precursor. By varying the deposition parameters, i.e. the electron beam current and energy and the raster constant, we obtain an artificial granular material with tunable electrical properties. The analysis of the temperature dependence of the conductivity and of the current-voltage characteristic suggests that the transport mechanism is governed by electron tunneling between artificial grains. In order to understand the nature of the granularity and thus the microstructural origin of the electronic transport behavior, we perform TEM and micro-Raman investigations. Independent of the deposition parameters, TEM measurements show that the dots are constituted of amorphous tungsten carbide clusters embedded in an amorphous carbonaceous matrix. Micro-Raman spectra show two peaks, around 690 and 860 cm-1 associated with the W-C stretching modes. Higher frequency peaks give information on the composition of the matrix. In particular, we measure a peak at about 1290 cm-1, which is associated with sp3 carbon bonds. Furthermore we detect the so-called D and G peaks, at about 1350 and 1560 cm-1, associated with the vibration modes of the sp2 carbon bonds. The analysis of the position of the peaks and of their relative intensity suggests that the composition of the matrix is between nanocrystalline graphite and amorphous carbon.

  11. Remote sensing of ELF/VLF radiation induced in experiments on artificial modification of the ionosphere

    Gavrilov, B. G.; Zetser, Yu. I.; Ryakhovskii, I. A.; Poklad, Yu. V.; Ermak, V. M.

    2015-07-01

    In 2012, remote measurements of electromagnetic signals in the ELF/VLF band were taken at different points in Russia during experiments on artificial ionospheric modification with the powerful HF wave at the EISCAT heating facility (Tromsø, Norway). The use of the new, highly sensitive magnetometric equipment allowed signals with an amplitude of a few femtoteslas to be recorded at a distance of up to 2000 km from the source. Analysis of the measurement results discovered substantial differences in the amplitude-phase characteristics of the signals, which were caused by a change in helio-geophysical conditions in the region of heating and along the signal passage route, and features of signal propagation, which are related to their mode of guided propagation, the directivity of the source, and angles of reception.

  12. Artificial neural network model of the strength of thin rectangular plates with weld induced initial imperfections

    Probabilistic assessment of post-buckling strength of thin plate is a difficult problem because of computational effort needed to evaluate single collapse load. The difficulties arise from the nonlinear behaviour of an in-plane loaded plate showing up multiple equilibrium states with possible bifurcations, snap-through or smooth transitions of states. The plate strength depends heavily on the shape of geometrical imperfection of the plate mid-surface. In this paper, an artificial neural network (ANN) is employed to approximate the collapse strength of plates as a function of the geometrical imperfections. For the training set, mainly theoretical imperfections with the corresponding collapse loads of plate calculated by FEM are considered. The ANN validation is based on the measured imperfections of ship plating and FEM strength.

  13. Artificial neural network model of the strength of thin rectangular plates with weld induced initial imperfections

    Sadovsky, Z., E-mail: usarzsad@savba.s [USTARCH SAV, Institute of Construction and Architecture, Slovak Academy of Sciences, 845 03 Bratislava (Slovakia); Guedes Soares, C. [Centre for Marine Technology and Engineering, Technical University of Lisbon, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal)

    2011-06-15

    Probabilistic assessment of post-buckling strength of thin plate is a difficult problem because of computational effort needed to evaluate single collapse load. The difficulties arise from the nonlinear behaviour of an in-plane loaded plate showing up multiple equilibrium states with possible bifurcations, snap-through or smooth transitions of states. The plate strength depends heavily on the shape of geometrical imperfection of the plate mid-surface. In this paper, an artificial neural network (ANN) is employed to approximate the collapse strength of plates as a function of the geometrical imperfections. For the training set, mainly theoretical imperfections with the corresponding collapse loads of plate calculated by FEM are considered. The ANN validation is based on the measured imperfections of ship plating and FEM strength.

  14. Leaching of artificial radionuclide out of minerals

    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

  15. Cardiomyopathy induced by artificial cardiac pacing: myth or reality sustained by evidence?

    Andrés Di Leoni Ferrari

    2014-09-01

    Full Text Available Implantable cardiac pacing systems are a safe and effective treatment for symptomatic irreversible bradycardia. Under the proper indications, cardiac pacing might bring significant clinical benefit. Evidences from literature state that the action of the artificial pacing system, mainly when the ventricular lead is located at the apex of the right ventricle, produces negative effects to cardiac structure (remodeling, dilatation and function (dissinchrony. Patients with previously compromised left ventricular function would benefit the least with conventional right ventricle apical pacing, and are exposed to the risk of developing higher incidence of morbidity and mortality for heart failure. However, after almost 6 decades of cardiac pacing, just a reduced portion of patients in general would develop these alterations. In this context, there are not completely clear some issues related to cardiac pacing and the development of this cardiomyopathy. Causality relationships among QRS widening with a left bundle branch block morphology, contractility alterations within the left ventricle, and certain substrates or clinical (previous systolic dysfunction, structural heart disease, time from implant or electrical conditions (QRS duration, percentage of ventricular stimulation are still subjecte of debate. This review analyses contemporary data regarding this new entity, and discusses alternatives of how to use cardiac pacing in this context, emphasizing cardiac resynchronization therapy.

  16. Induced radioactivity analysis for the NSRL Linac in China using Monte Carlo simulations and gamma-spectroscopy

    He, Lijuan; Li, Yuxiong; Li, Weimin; Chen, Zhi; Chen, Yukai; Ren, Guangyi

    2014-01-01

    The 200-MeV electron linac of the National Synchrotron Radiation Laboratory (NSRL) located in Hefei is one of the earliest high-energy electron linear accelerators in China. The electrons are accelerated to 200 MeV by five acceleration tubes and are collimated by scrapers. The scraper aperture is smaller than the acceleration tube one, so some electrons hit the materials when passing through them. These lost electrons cause induced radioactivity mainly due to bremsstrahlung and photonuclear r...

  17. Evaluation of a risk communication approach for maintenance staff working with induced radioactivity in medical linear accelerators

    In order to promote consensus building on decommissioning operation rules for medical linear accelerators in Japan, we carried out a risk communication (RC) approach mainly providing knowledge for maintenance staff regarding induced radioactivity. In February 2012, we created a booklet (26 pages) to present an overview of the amended law, the mechanism and the distribution of induced radioactivity showing the actual radiation dose rate around a linear accelerator and actual exposure doses to staff. In addition, we co-sponsored a seminar for workers in this field organized by the Japan Medical Imaging and Radiological Systems Industries Association to explain the contents of this booklet, and answer questions regarding induced radioactivity of linear accelerators as an RC program. As a result, the understanding of staff regarding the regulations on maximum X-ray energy on linear accelerators (P<0.05), and the outline of clearance systems (P<0.01), were facilitated by RC. In addition, we found that about 70% of maintenance staff considered that the cooling time for decommissioning operation depended on the situation. Our RC approach suggests that consensus building should be used to make rules on decommissioning operations for linear medical accelerators. (author)

  18. Radioactivity-induced modifications in the weight of the thyroid gland of the New Zealand adult rabbit

    Alcaraz, M.; Genoves, J.L.; Berna, J.D.; Meseguer, J.; Garcia-Ayala, A.

    1988-01-01

    The radioactivity-induced modifications in the weight of the thyroid gland of the New Zealand adult rabbit, as well as the radioactivity-induced ultrastructural changes underwent by these glands were studied. In order to achieve this, three groups, each of 36 animals, were established: One group regarded as erythroid, another of animal treated with propylthiouracil (PTU), and a third group treated with protirelin (TRH). The animals belonging to each group were distributed in six lots according to the total dose of radiation administered to their thyroid glands: 0 Gy (non-radiated group), 4 Gy, 8 Gy, 12 Gy, 12 Gy, 16 Gy and 20 Gy. The results obtained showed that the isolated use of thyroid gland weight as a biological parameter is not a specific indicator of the degree of radiosensitivity, nor of the status of functional glandular activity. The structural changes induced by radioactivity occurred earlier and were more intense in the group treated with protirelin (TRH) which was considered as hyperfunctioning.

  19. Radioactivity-induced, modifications in the weight of the thyroid gland of the New Zeland adult rabbit

    The radioactivity-induced modifications in the weight of the thyroid gland of the New Zealand adult rabbit, as well as the radioactivity-induced ultrastructural changes underwent by these glands were studied. In order to achieve this, three groups, each of 36 animals, were established: One group regarded as euthyroid, another of animal treated with propylthiouracil (PTU), and a thrid group treated with protirelin (TRH). The animals belonging to each group were distributed in six lots according to the total dosis of radiation administered to their thyroid glands: 0 Gy (non-radiated group), 4 Gy, 8 Gy, 12 Gy, 16 Gy and 20 Gy. The results obtained showed that the isolated use of thyroid gland weight as a biological parameters is not a specific indicator of the dregee of radiosensitivity, nor of the status of functional glandular activity. The structural changes induced by radioactivity occurred earlier and were more intense in the group treated with protirelin (TRH) which was considered as hyperfunctioning. (Author)

  20. Experimentally induced gluten enteropathy in artificially fed neonatal rats. Protective effect of epidermal growth factor (EGF)

    Štěpánková, Renata; Kofroňová, Olga; Tučková, Ludmila; Kozáková, Hana; Tlaskalová, Helena

    Paříž, 2002. s. 51. [International Symposium On Coeliac Disease /10./. 02.06.2002-05.06.2002, Paříž] R&D Projects: GA ČR GA303/00/1370 Grant ostatní: OLGI1999-000(FR) 50 Keywords : induced gluten * epidermal * growth factor Subject RIV: EE - Microbiology, Virology

  1. Force induced and electron stimulated STM manipulations: routes to artificial nanostructures as well as to molecular contacts, engines and switches

    Initially invented to image surfaces down to atomic scale, the scanning tunneling microscope (STM) has been further developed in the last few years to an operative tool, with which atoms and molecules can be manipulated at low substrate temperatures at will with atomic precision in different manners by using solely the tip-adparticle forces. In this way various artificial structures on nanoscale have been created and in situ characterized with the STM. Such structures as well as single molecules can be investigated by scanning tunnelling spectroscopy (STS) both with respect to their local electronic and even vibrational properties. Modifications of single molecules can be induced by using the tunnelling electron current: Rotations, diffusional jumps, vibrational excitations, desorption, dissociation and even association can be induced in individual molecules, often in a rather precise way by tuning the voltage into the energy levels of specific vibrations or electronic levels. These possibilities give rise to startling new opportunities for physical and chemical experiments on the single atom and single molecule level. Here a brief overview on results obtained with these new techniques is given

  2. Artificial neural network for Cu quantitative determination in soil using a portable Laser Induced Breakdown Spectroscopy system

    Laser Induced Breakdown Spectroscopy (LIBS) is an advanced analytical technique for elemental determination based on direct measurement of optical emission of excited species on a laser induced plasma. In the realm of elemental analysis, LIBS has great potential to accomplish direct analysis independently of physical sample state (solid, liquid or gas). Presently, LIBS has been easily employed for qualitative analysis, nevertheless, in order to perform quantitative analysis, some effort is still required since calibration represents a difficult issue. Artificial neural network (ANN) is a machine learning paradigm inspired on biological nervous systems. Recently, ANNs have been used in many applications and its classification and prediction capabilities are especially useful for spectral analysis. In this paper an ANN was used as calibration strategy for LIBS, aiming Cu determination in soil samples. Spectra of 59 samples from a heterogenic set of reference soil samples and their respective Cu concentration were used for calibration and validation. Simple linear regression (SLR) and wrapper approach were the two strategies employed to select a set of wavelengths for ANN learning. Cross validation was applied, following ANN training, for verification of prediction accuracy. The ANN showed good efficiency for Cu predictions although the features of portable instrumentation employed. The proposed method presented a limit of detection (LOD) of 2.3 mg dm-3 of Cu and a mean squared error (MSE) of 0.5 for the predictions

  3. Analysis of Correlation Between Urinal Excretion Ratio of Radioactive Iodine and Daily Urinal Excretion Volume

    Internal exposure to radionuclide results from depositing of radioactive substance within human body and is called intra-body exposure as well. Radioactive substance may find its way into human body via nose, mouth or skin and internal exposure to radionuclide is rarely ascribable to radioactive substance deposited through skin. Radioactive substances deposited in human tissues or organs do not stay there for good. Instead, they are transferred to other tissues, organs or excreted by sweat, excrements, urine and breath. However, natural excretion has its limits in terms of safeguarding human body actively against radioactive exposure. When radionuclide is deposited in human organs or tissues, diuretic or evacuant is used to induce excrements or urine to increase removal and discharging of radionuclide artificially, thereby reducing internal exposure. Therefore, we have attempted to propose an optimum approach to removing and excreting radioactive iodine by analyzing the correlation among the radioactive iodine intake ratio, daily urinal excretion ratio and volume

  4. Analysis of Correlation Between Urinal Excretion Ratio of Radioactive Iodine and Daily Urinal Excretion Volume

    Kim, Junghoon; Whang, Jooho [Kyunghee Univ., Yongin (Korea, Republic of); Kim, Teaman [The Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    2006-07-01

    Internal exposure to radionuclide results from depositing of radioactive substance within human body and is called intra-body exposure as well. Radioactive substance may find its way into human body via nose, mouth or skin and internal exposure to radionuclide is rarely ascribable to radioactive substance deposited through skin. Radioactive substances deposited in human tissues or organs do not stay there for good. Instead, they are transferred to other tissues, organs or excreted by sweat, excrements, urine and breath. However, natural excretion has its limits in terms of safeguarding human body actively against radioactive exposure. When radionuclide is deposited in human organs or tissues, diuretic or evacuant is used to induce excrements or urine to increase removal and discharging of radionuclide artificially, thereby reducing internal exposure. Therefore, we have attempted to propose an optimum approach to removing and excreting radioactive iodine by analyzing the correlation among the radioactive iodine intake ratio, daily urinal excretion ratio and volume.

  5. Natural radioactivity contents in tobacco and radiation dose induced from smoking

    One of the causative factors for cancer-inducing mechanisms in humans is radioactive elements present in tobacco leaves used in the manufacture of cigarettes. Smoking of tobacco and its products increases the internal intake and radiation dose due to naturally occurring radionuclides that are considered to be one of the most significant causes of lung cancer. In this work, different commercial types of cigarettes, cigar and moassel were collected from market. Naturally occurring radionuclides 226Ra and 214Bi (238U series), 228Ac and 228Ra (232Th series), 40K and man-made 137Cs were measured in tobacco using gamma-ray spectrometer. Results show that the average concentrations of 238U, 232Th and 40K were 4.564, 3.940 and 1289.53 Bq kg-1, respectively. This reflects their origin from the soil by root uptake and fertilisers used in the cultivation of tobacco plants. Concentration of 137Cs was 0.348 Bq kg-1 due to root uptake or deposition onto the leaf foliage. For smokers, the annual effective dose due to inhalation of 238U varied from 49.35 to 139.40 μSv-1 (average 104.27 μSv y-1), while of 232Th from 23.86 to 111.06 μSv y -1 (average 65.52 μSv y-1). The annual effective dose resulting from 137Cs was varied from 10.96 to 24.01 nSv y-1 (average 19.41 nSv y-1). (authors)

  6. Probing the connection of PBSs to the photosystems in Spirulina platensis by artificially induced fluorescence fluctuations

    Li Heng [Key Laboratory of Photochemistry, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Yang Shuzhen [Key Laboratory of Photochemistry, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Xie Jie [Key Laboratory of Photochemistry, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Zhao Jingquan [Key Laboratory of Photochemistry, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)]. E-mail: zhaojq@iccas.ac.cn

    2007-01-15

    The molecular architecture and the structural connections of phycobilisomes (PBSs) to the photosystems in the intact cells of Spirulina platensis were studied by taking advantage of glycerol- and betaine-induced fluorescence fluctuations. Generally, with a selective excitation of C-phycocyanin (C-PC), glycerol could induce not only decoupling of PBSs from the photosystems but also of C-PC rods from allophycocyanin (APC) cores, while betaine could strengthen the connection of PBSs to the thylakoid membrane but induce a partial dissociation of PBS. On the other hand, glycerol did not exert an influence on the fluorescence spectra of the photosystems in isolated thylakoid membrane. Therefore, it was deduced that glycerol could provide a molecular environment to weaken the hydrophobic interactions of not only the L{sub CM} with the membrane but also the linker polypeptides to the water-soluble phycobiliproteins (C-PC and APC), while the betaine could strengthen the hydrophobic interaction of L{sub CM} with the membrane but weaken the electrostatic interaction of linker polypeptides to C-PC and/or APC.

  7. Probing the connection of PBSs to the photosystems in Spirulina platensis by artificially induced fluorescence fluctuations

    The molecular architecture and the structural connections of phycobilisomes (PBSs) to the photosystems in the intact cells of Spirulina platensis were studied by taking advantage of glycerol- and betaine-induced fluorescence fluctuations. Generally, with a selective excitation of C-phycocyanin (C-PC), glycerol could induce not only decoupling of PBSs from the photosystems but also of C-PC rods from allophycocyanin (APC) cores, while betaine could strengthen the connection of PBSs to the thylakoid membrane but induce a partial dissociation of PBS. On the other hand, glycerol did not exert an influence on the fluorescence spectra of the photosystems in isolated thylakoid membrane. Therefore, it was deduced that glycerol could provide a molecular environment to weaken the hydrophobic interactions of not only the LCM with the membrane but also the linker polypeptides to the water-soluble phycobiliproteins (C-PC and APC), while the betaine could strengthen the hydrophobic interaction of LCM with the membrane but weaken the electrostatic interaction of linker polypeptides to C-PC and/or APC

  8. Artificial intelligence

    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

  9. The electrical charging of inactive aerosols in high ionised atmosphere, the electrical charging of artificial beta radioactive aerosols; Le processus de charge electrique: des aerosols non radioactifs en milieu fortement ionise, des aerosols radioactifs artificiels emetteurs beta

    Gensdarmes, F

    2000-07-01

    The electrical properties of aerosols greatly influence their transport and deposition in a containment. In a bipolar ionic atmosphere, a neutral electric charge on aerosols is commonly assumed. However, many studies report a different charge distribution in some situations, like highly ionised atmosphere or in the case of radioactive aerosols. Such situations could arise from a hypothetical accident in a nuclear power plant. Within the framework of safety studies which are carried out at IPSN, our aims were the study of electrical properties of aerosols in highly ionised atmosphere, and the study of artificial radioactive aerosols, in order to suggest experimental validation of available theories. For this purpose, we designed an experimental device that allows us to measure non-radioactive aerosol charge distribution under high gamma irradiation, up to 10{sup 4} Gy/h. With our experimental device we also studied the properties of small ions in the medium. Our results show a variation of the charge distribution in highly ionised atmosphere. The charge increases with the dose of gamma ray. We have related this variation with the one of the small ions in the gases, according to theoretical prediction. However, the model overestimates slightly our experimental results. In the case of the radioactive aerosols, we have designed an original experimental device, which allows us to study the charge distribution of a {sup 137}Cs aerosol. Our results show that the electric charging of such aerosols is strongly dependent on evolution parameters in a containment. So, our results underline a great enhancement of self-charging of particles which are sampled in a confined medium. Our results are qualitatively in agreement with the theoretical model; nevertheless the latter underestimates appreciably the self-charging, owing to the fact that wall effects are not taken into account. (author)

  10. Early age sealing of buffer-rock gap by artificial wetting to induce bentonite swelling

    Document available in extended abstract form only. The aim of this work is to study the homogeneous and rapid swelling of bentonite in the gap between the buffer blocks and the rock wall of the Olkiluoto disposal facility by artificial wetting. The focus was on the construction period of the deposition hole and buffer, and thus only the very early ages of the first weeks. In practice it is desirable that the bentonite material has a volume increase sufficient enough to prevent rock scaling while lowering the risks of bentonite piping and erosion due to potential water flow. This initial study was done in a small-scale mock-up in laboratory conditions. The small-scale steel mock-up had dimensions of 39 cm in height by 36 cm in diameter and included 12 pressure sensors, two displacement transducers, thermal couples, and pore water pressure measurements. The radial and axial pressure development was typically measured over a two week period to assess the rate and magnitude of sealing. A steel confining lid was used for simulating overpressure, though in some cases a plexiglass lid was used to take video images of the gap sealing. The buffer blocks were produced by isostatic compression of 100 MPa. The material was MX-80 Wyoming bentonite having a water content of approximately 13% and a dry density of 1890 kg/m3. The testing samples were dry sawn and core drilled from the large block and machined to their final dimensions. These were typically 30 x 30 cm, either as a solid block or three disks of 10 cm height each. The diameter was sometimes varied to allow for a change of gap width between 25 to 50 mm The study included various scenarios, such as: eccentric aligned blocks with gap sizes of 5 and 45 mm, free upward swelling or confinement, different types of pellet and granular gap filling, addition of water at varying rates, and longer term test duration. The samples were typically disassembled after two weeks. At this ending point, material assessments were done to quantify the variation of water content, SHORE hardness and density across the buffer and gap filling. The results showed that the bentonite buffer exposed to rapid artificial wetting is able to uniformly swelling to fill the gap within the first day with 25 mm gap. When only a water-filled gap was used, a radial pressure of about 200 kPa was achieved within the first few days with gas-tight steel lid in use. The pressure reached a maximum after about 2 weeks and then gradually declined due to moisture distribution from the gap towards the centre of the buffer block. Radial cracks appeared within the blocks within the test duration, which extended the full depth and across blocks. These could tighten and seal with prolonged testing or water addition. When gap filling materials were used, such as Cebogel pellets or Ibeco Seal granules, the radial pressure had maximum values up to 600 kPa. The pressure developed at a much faster rate and was better maintained over time, without the same type of pressure drop experienced with only an air-water filled gap. It was demonstrated that water could percolate through the pellet filling to be evenly distributed within a few minutes. This was also achieved in longer tube-filling tests simulating actual deposition holes, showing that when the pellets were placed by free-falling there was enough void space to allow full water filtration. The swollen material was well confined in the gap when an axial confining pressure was used from the start of testing. In some cases, the vertical, or axial, uplift pressure due to swelling was as much as double the radial pressure. Yet this could theoretically be counter-balanced by applying a confining load or lid to prevent buffer uplift into the tunnel backfill area. These post-test assessments showed that moisture equilibrium between the gap and buffer was not reached within the short test duration as expected. The outer gap filled material could have water contents on the order of 100 to 400% of the buffer. The area near the top of the sample often had a higher water content, attributed

  11. A comparative study of laser induced breakdown spectroscopy analysis for element concentrations in aluminum alloy using artificial neural networks and calibration methods

    A comparative study of analysis methods (traditional calibration method and artificial neural networks (ANN) prediction method) for laser induced breakdown spectroscopy (LIBS) data of different Al alloy samples was performed. In the calibration method, the intensity of the analyte lines obtained from different samples are plotted against their concentration to form calibration curves for different elements from which the concentrations of unknown elements were deduced by comparing its LIBS signal with the calibration curves. Using ANN, an artificial neural network model is trained with a set of input data of known composition samples. The trained neural network is then used to predict the elemental concentration from the test spectra. The present results reveal that artificial neural networks are capable of predicting values better than traditional method in most cases

  12. Measurement of Natural and Artificial Radioactivity in Soil at Some Selected Thanas around the TRIGA Mark-II Research Reactor at AERE, Savar, Dhaka

    Shawpan C. Sarkar; Idris Ali; Debasish Paul; Mahbubur R. Bhuiyan; Sheikh M. A. Islam

    2011-01-01

    The activity concentration of natural and fallout radionuclides in the soil at some selected Thanas around the TRIGA Mark-II Research Reactor at Atomic Energy Research Establishment (AERE), Savar, Dhaka were measured by using a high purity germanium detector (HPGe). The study revealed that only natural radionuclides were present in the samples and no trace of any artificial radionuclide was found. The average activity concentration of 238U, 232Th ...

  13. Piezomagnetic effects induced by artificial sources at Mt. Vesuvius (Italy: preliminary results of an experimental survey

    R. Napoli

    1998-06-01

    Full Text Available In order to put new constrains on magnetic effects associated with mechanical stresses, high frequency monitoring of the geomagnetic field was carried out during a seismic tomography experiment (TOMOVES'96 project at Mt. Vesuvius. Eight proton precession and one Cesium magnetometers were installed along a profile on the SW flank of the volcano to observe possible magnetic changes induced by explosions. Measurements were performed at different sampling frequencies (10 Hz, 0.5 Hz and 0.1 Hz. A remarkable change in the intensity of the magnetic field was observed in only one case. The magnetic transient lasted 12-13 min, reaching the maximum amplitude of slightly less than 15 nT.

  14. Rapid determination of small amount of plutonium in highly radioactive solution for safeguards assay by laser induced photoacoustic spectrometry

    Tokai Reprocessing Plant, Tokai Works is progressing a development of laser induced photoacoustic spectrometry (LIPAS) to determine the plutonium level of the solutions from nuclear fuel for operation management and nuclear material control as well as safeguards. The development of LIPAS is under way as a part of JASPAS, a supporting plan to International Atomic Energy Agency (IAEA). A considerable attention has been paid to LIPAS as a highly sensitive method following the development of highly luminant laser instruments. Pu(6) was chosen as the form to be assayed because Pu(6) was not affected by the presence of other elements in a highly radioactive solution. Since Pu in the solution ordinarily contains Pu(4), Pu determination was carried out after the conversion to Pu(6) by adding an oxidant. Both fundamental and practical investigations with highly radioactive solution by LIPS were presented in this report. (M.N.)

  15. The Influence of Acute Hyperglycemia in an Animal Model of Lacunar Stroke That Is Induced by Artificial Particle Embolization

    Tsai, Ming-Jun; Lin, Ming-Wei; Huang, Yaw-Bin; Kuo, Yu-Min; Tsai, Yi-Hung

    2016-01-01

    Animal and clinical studies have revealed that hyperglycemia during ischemic stroke increases the stroke's severity and the infarct size in clinical and animal studies. However, no conclusive evidence demonstrates that acute hyperglycemia worsens post-stroke outcomes and increases infarct size in lacunar stroke. In this study, we developed a rat model of lacunar stroke that was induced via the injection of artificial embolic particles during full consciousness. We then used this model to compare the acute influence of hyperglycemia in lacunar stroke and diffuse infarction, by evaluating neurologic behavior and the rate, size, and location of the infarction. The time course of the neurologic deficits was clearly recorded from immediately after induction to 24 h post-stroke in both types of stroke. We found that acute hyperglycemia aggravated the neurologic deficit in diffuse infarction at 24 h after stroke, and also aggravated the cerebral infarct. Furthermore, the infarct volumes of the basal ganglion, thalamus, hippocampus, and cerebellum but not the cortex were positively correlated with serum glucose levels. In contrast, acute hyperglycemia reduced the infarct volume and neurologic symptoms in lacunar stroke within 4 min after stroke induction, and this effect persisted for up to 24 h post-stroke. In conclusion, acute hyperglycemia aggravated the neurologic outcomes in diffuse infarction, although it significantly reduced the size of the cerebral infarct and improved the neurologic deficits in lacunar stroke.

  16. Diagnostic accuracy of artificially induced vertical root fractures: a comparison of direct digital periapical images with conventional periapical images

    To compare the diagnostic accuracy for the detection of root fractures in CMOS-based digital periapical images with conventional film-based periapical images. Sixty extracted single-root human teeth with closed apices were prepared endodontically and divided into two groups; artificially induced vertical root fracture group and control group. All radiographs were obtained using the paralleling technique. The radiographs were examined by 4 observers three times within a 4 week interval. Receiver operating characteristic (ROC) analysis was carried out using data obtained from four observers. Intra- and inter-examiner agreements were computed using kappa analysis. The area under the ROC curve (Az) was used as an indicator of the diagnostic accuracy of the imaging system. Az values were as follows: direct-digital images; 0.93, film-based images; 0.92, and inverted digital images; 0.91. There was no significant difference between imaging modalities(P<0.05). The kappa value of inter-observer agreement was 0.42(range:0.28-0.60) and intra-observer agreement was 0.57(range:0.44-0.75). There is no statistical difference in diagnostic accuracy for the detection of vertical root fractures between digital periapical images and conventional periapical images. The results indicate that the CMOS sensor is a good image detector for the evaluation of vertical root fractures.

  17. Morning sector drift-bounce resonance driven ULF waves observed in artificially-induced HF radar backscatter

    L. J. Baddeley

    Full Text Available HF radar backscatter, which has been artificially-induced by a high power RF facility such as the EISCAT heater at Tromsø, has provided coherent radar ionospheric electric field data of unprecedented temporal resolution and accuracy. Here such data are used to investigate ULF wave processes observed by both the CUTLASS HF radars and the EISCAT UHF radar. Data from the SP-UK-OUCH experiment have revealed small-scale (high azimuthal wave number, m -45 waves, predominantly in the morning sector, thought to be brought about by the drift-bounce resonance processes. Conjugate observations from the Polar CAM-MICE instrument indicate the presence of a non-Maxwellian ion distribution function. Further statistical analysis has been undertaken, using the Polar TIMAS instrument, to reveal the prevalence and magnitude of the non-Maxwellian energetic particle populations thought to be responsible for generating these wave types.

    Key words. Ionosphere (active experiments; wave-particle interactions Magnetospheric physics (MHD waves and instabilities

  18. HYPOTHALAMIC OREXINE SYSTEM ACCELERATES REGULATION OF SLEEP HOMEOSTASIS AND SLEEP-WAKEFULNESS CYCLE RECOVERY FROM BARBITURATE ANESTHESIA-INDUCED ARTIFICIAL SLEEP.

    Nachkebia, N; Maglakelidze, N; Chijavadze, E; Chkhartishvili, E; Babilodze, M

    2015-12-01

    The work was aimed for the ascertainment of following question - whether Orexin-containing neurons of dorsal and lateral hypothalamus and brain Orexinergic system in general are those cellular targets which can accelerate recovery of disturbed sleep homeostasis and restoration of sleep-wakefulness cycle behavioral states from barbiturate anesthesia-induced artificial sleep. Investigation was carried out on 18 wild type white rats (weight 200-250gr). Different doses of Nembutal Sodium were used for the initiation of deep anesthesia. 30 min after barbiturate anesthesia induced artificial sleep serial electrical stimulations of dorsal or lateral hypothalamus were started. Stimulation period lasted for 1 hour with the 5 min intervals between subsequent stimulations applied by turn to the left and right side hypothalamic parts. EEG registration of cortical and hippocampal electrical activity was started 10 min after intra-peritoneal administration of Nembutal Sodium and continued continuously during 72 hour. According to obtained new evidences, serial electrical stimulations of dorsal and lateral hypothalamic Orexin-containing neurons significantly accelerate recovery of wakefulness, sleep homeostasis, disturbed because of barbiturate anesthesia induced artificial sleep and different behavioral states of sleep-wakefulness cycle. Hypothalamic Orexin-containing neurons can be considered as the cellular targets for regulating of sleep homeostasis through the acceleration of recovery of wakefulness, and SWC in general, from barbiturate anesthesia-induced deep sleep. PMID:26719553

  19. Radioactive contamination of the biosphere

    The present volume deals with the main aspects of radioactive contamination of the biosphere. Cosmic radiation, natural sources of ionizing radiation, artificial radionuclides, radioactive fallout, radioactive wastes and connected problems are treated as well as the radioactivity and its interaction with the atmosphere, hydrosphere, soil and plant, animal and human organism. Problems of somatic and genetic radiation effects and of radiation protection are discussed finally

  20. Remote monostatic detection of radioactive material by laser-induced breakdown

    Isaacs, Joshua; Miao, Chenlong; Sprangle, Phillip

    2016-03-01

    This paper analyzes and evaluates a concept for remotely detecting the presence of radioactivity using electromagnetic signatures. The detection concept is based on the use of laser beams and the resulting electromagnetic signatures near the radioactive material. Free electrons, generated from ionizing radiation associated with the radioactive material, cascade down to low energies and attach to molecular oxygen. The resulting ion density depends on the level of radioactivity and can be readily photo-ionized by a low-intensity laser beam. This process provides a controllable source of seed electrons for the further collisional ionization (breakdown) of the air using a high-power, focused, CO2 laser pulse. When the air breakdown process saturates, the ionizing CO2 radiation reflects off the plasma region and can be detected. The time required for this to occur is a function of the level of radioactivity. This monostatic detection arrangement has the advantage that both the photo-ionizing and avalanche laser beams and the detector can be co-located.

  1. Three-dimentional simulation of flow-induced platelet activation in artificial heart valves

    Hedayat, Mohammadali; Asgharzadeh, Hafez; Borazjani, Iman

    2015-11-01

    Since the advent of heart valve, several valve types such as mechanical and bio-prosthetic valves have been designed. Mechanical Heart Valves (MHV) are durable but suffer from thromboembolic complications that caused by shear-induced platelet activation near the valve region. Bio-prosthetic Heart Valves (BHV) are known for better hemodynamics. However, they usually have a short average life time. Realistic simulations of heart valves in combination with platelet activation models can lead to a better understanding of the potential risk of thrombus formation in such devices. In this study, an Eulerian approach is developed to calculate the platelet activation in three-dimensional simulations of flow through MHV and BHV using a parallel overset-curvilinear immersed boundary technique. A curvilinear body-fitted grid is used for the flow simulation through the anatomic aorta, while the sharp-interface immersed boundary method is used for simulation of the Left Ventricle (LV) with prescribed motion. In addition, dynamics of valves were calculated numerically using under-relaxed strong-coupling algorithm. Finally, the platelet activation results for BMV and MHV are compared with each other.

  2. A new possible biological interface model useful to narrate the artificial negative events by the radioactive contaminations and heavy-metals pollution of the soil and the atmosphere in different areas of Europe

    A lot of environmental negative effects are associated to the pollution and radioactive contaminations of the soil and the atmosphere. Actually the C.I.S.A.M. (Interforces Centre for Studies and Military Applications) receives increasing commitments to control and to knowledge about the risks of the population and soldiers employed as stabilization or keeping peace force in large areas of different territories of Europe and other sites of the Planet. The aim of this work is focused to compare the contents of radionuclides on specific natural interfaces in different areas as residual radioactive contamination in addition to the other possible heavy-metals pollution. We used barks, lichens and symbiontic microalgae as interfaces with the atmospheric events of the Chernobyl, Balkan, and the Italian areas. The qualitative analysis of these biological matters showed the constant presence of Radiocesium, along with other radionuclides, of which we report the concentrations. Even if these observations are not completely new, nevertheless we can suppose that this approach could be a new possible interface model useful to narrate the sequence of the the artificial negative events due to the human activities and contemporarely an indirect valuation of different risks pointed to the protection of the exposed population

  3. Artificial Limbs

    ... you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which ... activities such as walking, eating, or dressing. Some artificial limbs let you function nearly as well as ...

  4. Induced radioactivity in the blood of cancer patients following Boron Neutron Capture Therapy

    Fujiwara, Keiko; Kinashi, Yuko; TAKAHASHI, TOMOYUKI; Yashima, Hiroshi; Kurihara, Kouta; Sakurai, Yoshinori; TANAKA, HIROKI; ONO, Koji; Takahashi, Sentaro

    2013-01-01

    Since 1990, Boron Neutron Capture Therapy (BNCT) has been used for over 400 cancer patients at the Kyoto University Research Reactor Institute (KURRI). After BNCT, the patients are radioactive and their 24Na and 38Cl levels can be detected via a Na-I scintillation counter. This activity is predominantly due to 24Na, which has a half-life of 14.96 h and thus remains in the body for extended time periods. Radioactive 24Na is mainly generated from 23Na in the target tissue that is exposed to the...

  5. An approximate relation for the prediction of the dose rate from radioactivity induced in high energy particle accelerators

    Sullivan, A H

    1972-01-01

    If the dose rate from radioactivity induced by high energy particle radiation depends on irradiation time T and decay time T according to D=K0log (T+t/T), where 0 is the flux density of high-energy particles causing the activation and K is a constant for any given set of irradiation, target and geometrical conditions, then this paper shows that K can be estimated such that the formula can be used to make absolute dose rate predictions of sufficient accuracy for radiation protection purposes.

  6. Reaction dynamics induced by the radioactive ion beam 7Be on medium-mass and heavy targets

    We studied the reaction dynamics induced at Coulomb barrier energies by the weakly-bound Radioactive Ion Beam 7Be (Sα = 1.586 MeV) on medium-mass (58Ni) and heavy (208Pb) targets. The experiments were performed at INFN-LNL (Italy), where a 2-3×105 pps 7Be secondary beam was produced with the RIB in-flight facility EXOTIC. Charged reaction products were detected by means of high-granularity silicon detectors in rather wide angular ranges. The contribution presents an up-to-date status of the data analysis and theoretical interpretation for both systems

  7. Reaction dynamics induced by the radioactive ion beam 7Be on medium-mass and heavy targets

    Mazzocco, M.; Boiano, A.; Boiano, C.; La Commara, M.; Manea, C.; Parascandolo, C.; Pierroutsakou, D.; Stefanini, C.; Strano, E.; Torresi, D.; Acosta, L.; Di Meo, P.; Fernandez-Garcia, J. P.; Glodariu, T.; Grebosz, J.; Guglielmetti, A.; Keeley, N.; Lay, J. A.; Marquinez-Duran, G.; Martel, I.; Mazzocchi, C.; Molini, P.; Nicoletto, M.; Pakou, A.; Parkar, V. V.; Rusek, K.; Sánchez-Benítez, A. M.; Sandoli, M.; Sava, T.; Sgouros, O.; Signorini, C.; Silvestri, R.; Soramel, F.; Soukeras, V.; Stiliaris, E.; Stroe, L.; Toniolo, N.; Zerva, K.

    2015-10-01

    We studied the reaction dynamics induced at Coulomb barrier energies by the weakly-bound Radioactive Ion Beam 7Be (Sα = 1.586 MeV) on medium-mass (58Ni) and heavy (208Pb) targets. The experiments were performed at INFN-LNL (Italy), where a 2-3×105 pps 7Be secondary beam was produced with the RIB in-flight facility EXOTIC. Charged reaction products were detected by means of high-granularity silicon detectors in rather wide angular ranges. The contribution presents an up-to-date status of the data analysis and theoretical interpretation for both systems.

  8. A quantitative analysis of microbially-induced calcite precipitation employing artificial and naturally-occurring sediments

    Lokier, Stephen; Krieg Dosier, Ginger

    2013-04-01

    Microbially-induced calcite precipitation is a strong candidate for the production of sustainable construction materials. The process employs the microbe Sporosarcina pasteurii as an agent to microbially mediate the precipitation of calcium carbonate to bind unconsolidated sediment. As this process can be achieved under ambient temperature conditions and can utilise a wide variety of easily-available sediments, potentially including waste materials, it is envisioned that this procedure could significantly reduce carbon-dioxide emissions in the construction industry. This study describes and quantifies the precipitation of calcite cement in a range of naturally-occurring sediments compared with a control matrix. The study establishes the optimum treatment time for effective cement precipitation in order to produce a material that meets the standards required for construction whilst keeping economic and environmental outlays at a minimum. The 'control sediment' employed industrial-grade glass beads with a grain size range of 595-1180 microns (16-30 US mesh). Sporosarcina pasteurii were mixed in a solution of urea and calcium chloride and then inoculated into the control sediment. The microbes attach to the surface of the sediment grains and employ urea as a source of energy to produce ammonia and carbon dioxide. By so doing, they increase the pH of the solution allowing calcium carbonate to precipitate at the cell walls to act as nucleation points facilitating the precipitation of cements as a grain-coating and biocementing the unconsolidated sediment. The solution treatment was repeated at eight hour intervals with samples removed for detailed analysis after each every five consecutive treatments (i.e. 40 hours). The process was repeated to produce 20 samples with treatment times between 40 and 800 hours. Cemented samples were impregnated with blue epoxy and examined petrographically to monitor cement development. Modal analysis was undertaken on each cemented sample to establish the abundance and natures of precipitated cements. Samples were also examined via SEM to monitor cement distribution and quantify the thickness of cements on grain surfaces and at grain-on-grain contacts. Analysis established that precipitation of calcite continues until 400 hours (50 treatments) after which time there is only an insignificant precipitation of new calcite cement. This is inferred to result from the occlusion of porosity (from 40% to 10%) and observed calcite precipitation at grain-on-grain contacts, both factors reduce the permeability of the samples and, thus, inhibit the flow of solution through the medium. The precipitated calcite cement was found to be dominantly grain-rimming with a consistent thickness averaging 11 microns. A range of naturally-occurring sediments were collected from surface locations throughout the United Arab Emirates. Samples were submitted to a range of petrographic and geochemical analysis in order to quantify grain-size distribution, grain composition and bulk total carbonate content (7.5-94 wt%). Sub-samples of these sediments were established by sieving and the cementation potential of different size fractions was established. Following treatment, these samples were submitted to the same analysis as those employed for the control sediment. A relationship between both sediment grain-size characteristics and sediment grain composition to cement precipitation was established and is discussed.

  9. Residual neutron-induced radioactivities of Co-60 and Eu-152 in rocks exposed to Nagasaki Atomic Bomb

    Radioactivities of residual neutron-induced radionuclides of Co-60 and Eu-152 in rocks exposed by Nagasaki Atomic Bomb were determined. Samples were obtained from the surface to 2 cm in depth of rocks. Each sample was pulverized and placed in a plastic container, and gamma-ray spectrum was measured with a pure germanium semiconductor detector. To determine the amount of natural element of cobalt and europium contained in each sample, the neutron activation method was performed by the reactor of the Research Reactor Institute, Kyoto University (KUR). The radioactivities of Co-60 and Eu-152 were evaluated as per 1 mg natural element at the time of Atomic Bomb. The results show that the radioactivities of Co-60 and Eu-152 in rocks were decreased with increasing slant distance. The Co-60 activity was 6.882.13 Bq/mgCo and the Eu-152 activity was 75.98.79 Bq/mgEu at 510 m from the epicenter. When we compared the activity of Eu-152 calculated by Loewe with our data, we found a divergence between them as the distance from the epicenter increases. (author)

  10. Induced radioactivity in the blood of cancer patients following Boron Neutron Capture Therapy

    Since 1990, Boron Neutron Capture Therapy (BNCT) has been used for over 400 cancer patients at the Kyoto University Research Reactor Institute (KURRI). After BNCT, the patients are radioactive and their 24Na and 38Cl levels can be detected via a Na-I scintillation counter. This activity is predominantly due to 24Na, which has a half-life of 14.96 h and thus remains in the body for extended time periods. Radioactive 24Na is mainly generated from 23Na in the target tissue that is exposed to the neutron beam in BNCT. The purpose of this study is to evaluate the relationship between the radioactivity of blood 24Na following BNCT and the absorbed gamma ray dose in the irradiated field. To assess blood 24Na, 1 ml of peripheral blood was collected from 30 patients immediately after the exposure, and the radioactivity of blood 24Na was determined using a germanium counter. The activity of 24Na in the blood correlated with the absorbed gamma ray doses in the irradiated field. For the same absorbed gamma ray dose in the irradiated field, the activity of blood 24Na was higher in patients with neck or lung tumors than in patients with brain or skin tumors. The reasons for these findings are not readily apparent, but the difference in the blood volume and the ratio of bone to soft tissue in the irradiated field, as well as the dose that leaked through the clinical collimator, may be responsible. (author)

  11. Radioactivity in the environment

    The book summarizes general concepts on radiation, nuclear structure, radioactivity and the interaction of the nuclear radiation with matter. It describes also the basic principles of radio dosimetry. Natural and artificial sources of radiation are reviewed as well as the effects of radiation in man. Medical and industrial applications of ionizing radiation and the pollution produced by the discharge of radioactive materials are outlined. A short review is made of the safety rules and the regulations concerning the protection of the environment

  12. Assessment of natural and artificial radioactivity levels and radiation hazards and their relation to heavy metals in the industrial area of Port Said city, Egypt.

    Attia, T E; Shendi, E H; Shehata, M A

    2015-02-01

    A detailed gamma ray spectrometry survey was carried out to make an action in environmental impact assessment of urbanization and industrialization on Port Said city, Egypt. The concentrations of the measured radioelements U-238, Th-232 in ppm, and K-40 %, in addition to the total counts of three selected randomly dumping sites (A, B, and C) were mapped. The concentration maps represent a base line for the radioactivity in the study area in order to detect any future radioactive contamination. These concentrations are ranging between 0.2 and 21 ppm for U-238 and 0.01 to 13.4 ppm for Th-232 as well as 0.15 to 3.8 % for K-40, whereas the total count values range from 8.7 to 123.6 uR. Moreover, the dose rate was mapped using the same spectrometer and survey parameters in order to assess the radiological effect of these radioelements. The dose rate values range from 0.12 to 1.61 mSv/year. Eighteen soil samples were collected from the sites with high radioelement concentrations and dose rates to determine the activity concentrations of Ra-226, Th-232, and K-40 using HPGe spectrometer. The activity concentrations of Ra-226, Th-232, and K-40 in the measured samples range from 18.03 to 398.66 Bq kg(-1), 5.28 to 75.7 Bq kg(-1), and 3,237.88 to 583.12 Bq kg(-1), respectively. In addition to analyze heavy metal for two high reading samples (a 1 and a 10) which give concentrations of Cd and Zn elements (a 1 40 ppm and a 10 42 ppm) and (a 1 0.90 ppm and a 10 0.97 ppm), respectively, that are in the range of phosphate fertilizer products that suggested a dumped man-made waste in site A. All indicate that the measured values for the soil samples in the two sites of three falls within the world ranges of soil in areas with normal levels of radioactivity, while site A shows a potential radiological risk for human beings, and it is important to carry out dose assessment program with a specifically detailed monitoring program periodically. PMID:25233912

  13. Alloy development for fast induced radioactivity decay for fusion reactor applications

    The Cr-Mo ferritic (martensitic) steels and austenitic stainless steels (primarily type 316 and variations on that composition) are the leading candidates for the structural components for future fusion reactors. However, irradiation of such steels in a fusion environment produces long-lived radioactive isotopes. These isotopes lead to difficult radioactive waste disposal problems once the structure is removed from service. Such problems could be reduced by developing steels that contain only elements that produce radioactive isotopes that decay to low levels in a reasonable time (tens of years instead of hundreds or thousands of years). This report discusses the development of such steels by making elemental substitutions in the steels now under consideration. Molybdenum must be replaced in the Cr-Mo steels; nickel and molybdenum both must be replaced in the austenitic stainless steels (the nitrogen concentration must be limited, and niobium, maintained to extremely low levels). Appropriate substitutions are tungsten for molybdenum in the Cr-Mo steels and manganese for nickel in the austenitic stainless steels. Indications are that suitable ferritic steels can be developed, but development of a nickel-free austenitic stainless steel with properties similar to the Cr-Ni stainless steels appears to be much more complex

  14. Analysis of natural and artificial ultramarine blue pigments using laser induced breakdown and pulsed Raman spectroscopy, statistical analysis and light microscopy

    Osticioli, I.; Mendes, N. F. C.; Nevin, A.; Gil, Francisco P. S. C.; Becucci, M.; Castellucci, E.

    2009-08-01

    Pulsed laser induced breakdown spectroscopy (LIBS) and Raman spectroscopy were performed using a novel laboratory setup employing the same Nd:YAG laser emission at 532 nm for the analysis of five commercially available pigments collectively known as "ultramarine blue", a sodium silicate material of either mineral origin or an artificially produced glass. LIBS and Raman spectroscopy have provided information regarding the elemental and molecular composition of the samples; additionally, an analytical protocol for the differentiation between natural (lapis lazuli) and artificial ultramarine blue pigments is proposed. In particular LIBS analysis has allowed the discrimination between pigments on the basis of peaks ascribed to calcium. The presence of calcite in the natural blue pigments has been confirmed following Raman spectroscopy in specific areas of the samples, and micro-Raman and optical microscopy have further corroborated the presence of calcite inclusions in the samples of natural origin. Finally multivariate analysis of Laser induced breakdown spectra using principal component analysis (PCA) further enhanced the differentiation between natural and artificial ultramarine blue pigments.

  15. Study of the sorption of some artificial radioelements by pelitic sediments for the purpose of application to the radioactive labeling of these materials

    The radioactive labeling of silt is in itself difficult, the main obstacle being the identity of the dynamic properties of these sediments before and after labeling. The aim of this study is to examine in detail the labeling processes, the methods used and their success with regard to the above criterion. The author, having shown that labeling by direct activation and by simulators such as ground glass fail to fulfil the conditions of a good mixture, explores surface fixation techniques for 198Au, 51Cr, 46Sc and 192Ir. The ideal labeling conditions are determined and evidence is collected in relation to the actual fixation of the tracer. Finally the dynamic properties of a natural sediment are compared with those of a sediment labeled by the methods described here. (author)

  16. Measurement of induced radioactivities for the evaluation of internal exposure at high energy accelerator facilities

    At high-intense and high energy accelerator facilities, accelerator components are exposed to primary and/or secondary high energy particles during machine operation. As a result, these become radioactive and the radioactivities are accumulated with operation time. When workers engage in maintenance work such as cutting, welding, etc. in the areas with residual activities. These become a source of internal exposure through the inhalation of radioactive airbornes as well as a source of external exposure. The estimation of external doses to workers is relatively easy by directly measuring the radiation fields by pertinent radiation counters. While the internal dose depends very much on the kinds of radioactive nuclides and their concentrations in air. In a routine survey for internal dose evaluation, airborne activities are filtered and their activities on the filter are measured with a GM counter with an automatic sample changer at KEK (the High Energy Accelerator Research Organization). Ordinarily many filter samples have to be measured with a relatively short counting time, so this gross beta counting is a practical way in a routine procedure. In order to evaluate the internal dose from these countings, it is necessary to examine precisely the kinds of radioactivities and their concentrations collected on the filters by a Ge semiconductor detector, and the correlation between the gross beta counting and the actual dose has to be made clear in advance. However, kinds of radioactivities and their concentrations depend very much on production rates of individual nuclides and time variations after beam-off. First, in order to elucidate the production rates of individual nuclides and their concentrations after beam-off, metal samples of Al, Fe, Cu, Steel, etc., which are principal materials used in accelerator facilities, were irradiated at various places in the tunnel of KEK-500MeV and 12GeV proton synchrotrons. By using these irradiated samples, we examined extensively a GM gross counting method for evaluation of internal doses and compared it with a Ge counting method under various conditions. The application, of this gross beta counting method to actual situations at high energy accelerator facilities is discussed. Further, Fe-55 is abundantly produced in accelerator components, however both above methods can not be applicable to the estimation of internal doses due to this isotope because Fe-55 decays through EC process with low energy X-rays and no gamma-ray. A low energy photon spectroscopy (LEPS) using a Ge-semiconductor was applied to the measurement of Fe-55 in activated components. In routine work, it is very convenient if the radioactivity of Fe-55 can be deduced from the concentrations of other long-lived isotopes such as Mn-54, Cr-51, concomitantly present in those irradiated materials. We examined extensively the possibility of direct evaluation of Fe-55 internal doses. (author)

  17. Numerical Simulation and Artificial Neural Network Modeling for Predicting Welding-Induced Distortion in Butt-Welded 304L Stainless Steel Plates

    Narayanareddy, V. V.; Chandrasekhar, N.; Vasudevan, M.; Muthukumaran, S.; Vasantharaja, P.

    2016-02-01

    In the present study, artificial neural network modeling has been employed for predicting welding-induced angular distortions in autogenous butt-welded 304L stainless steel plates. The input data for the neural network have been obtained from a series of three-dimensional finite element simulations of TIG welding for a wide range of plate dimensions. Thermo-elasto-plastic analysis was carried out for 304L stainless steel plates during autogenous TIG welding employing double ellipsoidal heat source. The simulated thermal cycles were validated by measuring thermal cycles using thermocouples at predetermined positions, and the simulated distortion values were validated by measuring distortion using vertical height gauge for three cases. There was a good agreement between the model predictions and the measured values. Then, a multilayer feed-forward back propagation neural network has been developed using the numerically simulated data. Artificial neural network model developed in the present study predicted the angular distortion accurately.

  18. Artificial heart

    Nishta, B.V.

    2014-01-01

    An artificial heart is a device that replaces the heart. Artificial hearts are typically used to bridge the time to heart transplantation, or to permanently replace the heart in case heart transplantation is impossible. Although other similar inventions preceded it are going back to the late 1940s, the first artificial heart to be successfully implanted in a human was the Jarvik-7, designed by Robert Jarvik and implemented in 1982. When you are citing the document, use the following link h...

  19. Neutron yield and induced radioactivity: a study of 235-MeV proton and 3-GeV electron accelerators.

    Hsu, Yung-Cheng; Lai, Bo-Lun; Sheu, Rong-Jiun

    2016-01-01

    This study evaluated the magnitude of potential neutron yield and induced radioactivity of two new accelerators in Taiwan: a 235-MeV proton cyclotron for radiation therapy and a 3-GeV electron synchrotron serving as the injector for the Taiwan Photon Source. From a nuclear interaction point of view, neutron production from targets bombarded with high-energy particles is intrinsically related to the resulting target activation. Two multi-particle interaction and transport codes, FLUKA and MCNPX, were used in this study. To ensure prediction quality, much effort was devoted to the associated benchmark calculations. Comparisons of the accelerators' results for three target materials (copper, stainless steel and tissue) are presented. Although the proton-induced neutron yields were higher than those induced by electrons, the maximal neutron production rates of both accelerators were comparable according to their respective beam outputs during typical operation. Activation products in the targets of the two accelerators were unexpectedly similar because the primary reaction channels for proton- and electron-induced activation are (p,pn) and (γ,n), respectively. The resulting residual activities and remnant dose rates as a function of time were examined and discussed. PMID:25628454

  20. Ambient radioactivity levels and radiation doses. Annual report 2012

    The annual report 2012 on ambient radioactivity levels and radiation doses covers the following issues: Part A: General information: natural environmental radioactivity; artificial radioactivity in the environment; occupational radiation exposure; radiation exposures from medical applications; the handling of radioactive materials and sources of ionizing radiation; non-ionizing radiation. Part B: Current data and their evaluation: natural environmental radioactivity; artificial radioactivity in the environment; occupational radiation exposures; radiation exposures from medical applications; the handling of radioactive materials and sources of ionizing radiation; non-ionizing radiation. The report includes data on the stock of radioactive waste, radiation accidents and unusual events.

  1. Study of a method of detection for natural carbon-14 using a liquid scintillator, recent variations in the natural radio-activity due to artificial carbon-14 (1963)

    Among the various natural isotopes of carbon, a radioactive isotope, carbon-14, is formed by the action of secondary neutrons from cosmic rays on nitrogen in the air. Until 1950, the concentration of this isotope in ordinary carbon underwent weak fluctuations of about 2-3 per cent. The exact measurement of this concentration 6 X 1012 Ci/gm of carbon, and of its fluctuations, are difficult and in the first part of this report a highly sensitive method is given using a liquid scintillator. Since 1950 this natural activity has shown large fluctuations because of the carbon-14 formed during nuclear explosions, and in the second part, the evolution in France of this specific activity of carbon in the atmosphere and biosphere is examined. In the last part is studied the local increase in carbon activity in the atmosphere around the Saclay site, an increase caused by the carbon-14 given off as C14O2, by the reactors cooled partially with exterior air. (author)

  2. Artificial blood

    Sarkar Suman

    2008-01-01

    Full Text Available Artificial blood is a product made to act as a substitute for red blood cells. While true blood serves many different functions, artificial blood is designed for the sole purpose of transporting oxygen and carbon dioxide throughout the body. Depending on the type of artificial blood, it can be produced in different ways using synthetic production, chemical isolation, or recombinant biochemical technology. Development of the first blood substitutes dates back to the early 1600s, and the search for the ideal blood substitute continues. Various manufacturers have products in clinical trials; however, no truly safe and effective artificial blood product is currently marketed. It is anticipated that when an artificial blood product is available, it will have annual sales of over $7.6 billion in the United States alone.

  3. Study of the artificial radioactivity of the marine medium using gamma spectrometry (1962-1966); Etude de la radioactivite artificielle du milieu marin par spectrometrie gamma (1962-1966)

    Chesselet, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    The results described in this study are relative to the artificial radioactivity of such elements as zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 and praseodymium-144 which were present in the atmospheric fallout between 1962 and 1964, and their incidence in superficial marine waters. Various physical, chemical or biological processes are studied by a high sensitivity gamma ray spectrometry technic, using those radioelements as 'tracers'. The change of state in sea water of an important fraction (about 50 per cent) of the radioactive particles going into the soluble phase - this phenomenon was not expected for those radioelements - controls the processes of accumulation in the planktonic biomass and the diffusion towards deeper waters. On the other hand, an 'in situ' spectrometry method is described. It enables the direct measurement in the sea of very low concentrations of some gamma ray emitters. The application of this method has made possible to carry out numerous observations in the surface waters of the Western Mediterranean sea and in the Bay of Biscay. It is shown that the mixing depth is closely connected to the depth of the thermocline. An accumulation process at this level is observed. The diffusion coefficients are similar to the thermal turbulent coefficient. The existence during several months of 'compartments' is established for the surface waters of the Bay of Biscay. From the establishment of the budget of fall-out, a comparative study shows that the rate of radioactive fallout on the maritime zone considered is always two to three times higher than on the neighbouring continental regions. Several explanations of this phenomenon are discussed. (author) [French] Les resultats decrits dans cette etude concernent la radioactivite artificielle sous forme de zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 et praseodyme-144 apportee par la retombee atmospherique entre 1962 et 1964 et les incidences de cette retombee dans les eaux marines superficielles. Considerant les radioelements etudies comme des 'traceurs' dans le milieu marin, divers processus physiques, chimiques ou biologiques ont ete etudies par spectrometrie gamma a haute sensibilite. Le passage en phase soluble dans l'eau de mer d'une fraction importante (environ 50 pour cent) de l'activite liee aux poussieres radioactives, phenomene qui n'etait pas previsible pour les radioelements etudies, gouverne les processus d'accumulation dans la biomasse planctonique et la diffusion vers les eaux plus profondes. Par ailleurs, une methode de spectrometrie 'in situ' permettant de mesurer directement dans la mer de tres faibles concentrations en certains radionuclides emetteurs gamma est decrite. L'application de cette methode a permis de nombreuses observations dans les eaux de surface de la Mediterranee occidentale et du Golfe de Gascogne. On montre quo la profondeur de melange est etroitement liee a celle de la thermocline. Un processus d'accumulation au niveau de celle-ci est constate. Les coefficients de diffusion sont voisins du coefficient de diffusion thermique turbulente. L'existence de compartiments qui subsistent pendant plusieurs mois dans la masse des eaux de surface du Golfe de Gascogne est mise en evidence. Grace aux bilans effectues, une etude comparative montre que le taux de retombees radioactives sur les surfaces maritimes est toujours deux a trois fois superieur a celui sur les regions continentales voisines. Diverses explications de ce phenomene sont discutees. (auteur)

  4. Induced radioactivity in a mercury target and solenoid for a 24 GeV proton target test

    Magistris, Matteo; Silari, Marco

    2006-06-01

    In the framework of the feasibility study for a future neutrino-production facility, an experiment has been proposed at CERN as a proof-of-principle demonstration of a target system based on a free mercury jet suitable for use in a 4-MW pulsed proton beam. This paper estimates the expected amount of induced radioactivity in the various components of the target-solenoid assembly of the experiment to be carried out at the 24 GeV CERN proton synchrotron. The total activity expected in the mercury target and the specific activities in the components of the solenoid are assessed by Monte Carlo simulations with the FLUKA code. The residual dose rates for various decay times after the end of the irradiation are calculated. The environmental impact of the release of the activated nitrogen used to cool the solenoid is evaluated.

  5. Induced radioactivity in a mercury target and solenoid for a 24 GeV proton target test

    In the framework of the feasibility study for a future neutrino-production facility, an experiment has been proposed at CERN as a proof-of-principle demonstration of a target system based on a free mercury jet suitable for use in a 4-MW pulsed proton beam. This paper estimates the expected amount of induced radioactivity in the various components of the target-solenoid assembly of the experiment to be carried out at the 24 GeV CERN proton synchrotron. The total activity expected in the mercury target and the specific activities in the components of the solenoid are assessed by Monte Carlo simulations with the FLUKA code. The residual dose rates for various decay times after the end of the irradiation are calculated. The environmental impact of the release of the activated nitrogen used to cool the solenoid is evaluated

  6. Domain wall resistance between artificial domains created in exchange coupled bilayers by keV He ion bombardment induced magnetic patterning

    Ion bombardment induced lateral magnetic patterning (IBMP) has been used to generate different magnetic patterns (artificial domains) in an exchange bias bilayer system without changes in the surface topography. This technique enables to create adjacent areas with designed magnetization directions stable in remanence. Within the same layer system it is possible to create Bloch or Neel walls. Corresponding magnetical stripe patterns were analyzed by magnetic force microscopy and Kerr microscopy. Magnetoresistance measurements were performed to investigate the domain wall resistance (DWR) at room temperature and low temperatures.

  7. Induced Radioactivity Measured in a Germanium Detector After a Long Duration Balloon Flight

    Starr, R.; Evans, L. G.; Floyed, S. R.; Drake, D. M.; Feldman, W. C.; Squyres, S. W.; Rester, A. C.

    1997-01-01

    A 13-day long duration balloon flight carrying a germanium detector was flown from Williams Field, Antartica in December 1992. After recovery of the payload the activity induced in the detector was measured.

  8. THE INTEGRAL ESTIMATION OF PERCEIVED DISCOMFORT CONDITION OF THE URANIUM PROCESSING ENTERPRISE EMPLOYEES AND CITY RESIDENTS WITH ARTIFICIALLY INCREASED NATURAL SOURCE OF RADIOACTIVITY

    Shevchenko О. A.

    2014-03-01

    Full Text Available Introduction. After the Chernobyl accident radio-anxiety of the population remains one of the most acute psychosocial problems in Ukraine, especially in the regions where uranium is extracted and processed. Uranium raw material – basis of nuclear fuel for nuclear energy – has been processed in Zhovti Vody of Dnipropetrovsk region since 1950s. Zhovti Vody is a unique place. The city is surrounded with the uranium production facilities: the hydrometallurgical factory and the uranium waste tailing damp. Purpose. Our aim was to estimate perceived health status of Zhovti Vody citizens (population category «В» and the employees of the industrial complex «Eastern Mining Processing Plant» (MPP, who work with radiation sources daily (categories «A» and «B». Materials and Methods. We checked the health status of average Zhovti Vody citizens (102 and industrial complex employees (104, who work with radiation sources daily. The samplings deferred only by the place of employment of respondents. The average age of respondents (M ± m was 41.6 ± 0.9 years. The gender (р > 0.9 and age (р > 0.7 characteristics were similar for both groups. The applied research methods were developed and tested by the specialists of V. M. Bekhterev Psychoneurological Research Institute (Saint Petersburg. Discussion 1. According to the integral estimation of the perceived discomfort condition: the employees complained less of pain, but citizens who did not work in the industrial complex complained more. 2. Mental health of the population corresponds to the low (by anxiety and frustration indices and middle assessment levels (on the constriction and aggressiveness scales. However, the employees of the industrial complex showed the lower degree of symptom expression. 3. The majority of population (88.3 % showed the low level of social frustration regardless to the place of employment. 4. The correlation between physical and mental health statuses (anxiety, constriction, psychological and social frustration confirmed interaction between pain and psychological symptoms. The employees of the industrial complex showed better estimation of perceived health status comparing with citizens, who work in other institutions. Thus, the employees of any industrial complexes normally express less radio-anxiety, because they work with radioactive sources daily.

  9. Radioactive waste disposal in granite

    Within the framework of completing its knowledge of various rock formations, the Federal Government also considers the suitability of granite for radioactive waste disposal. For this purpose, the Federal Minister of Research and Technology participated from 1983 to 1990 in relevant research and development activities in the NAGRA rock laboratory at Grimsel, Switzerland. After about 17 field tests, it can be stated that the understanding of basic connections and interactions between the mechanical behaviour of the rock, which is determined, for instance, by natural or artificially induced rock movements, and the hydrogeological or rock hydraulic relations could be clearly improved. So far, the German share in the project costs amounts to a total of approximately DM 20.7 million. Till the end of 1993, further activities are scheduled to be carried out which will require financial funds of about DM 6.3 million. (orig./HSCH)

  10. Artificial intelligence

    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

  11. Osmosis-induced swelling of Eurobitum bituminized radioactive waste in constant total stress conditions

    In geological disposal conditions, contact of Eurobitum bituminized radioactive waste, which contains high amounts of the hygroscopic and highly soluble NaNO3, with groundwater will result in water uptake and swelling of the waste, and in subsequent leaching of the embedded NaNO3 and radionuclides. The swelling of and the NaNO3 leaching from non-radioactive Eurobitum samples, comprised between two stainless steel filters and in contact with 0.1 M KOH, was studied in restricted (semi-confined) swelling conditions, i.e. under a constant total stress, or counterpressure, of 2.2, 3.3, or 4.4 MPa (i.e. oedometer conditions). Four tests were stopped after hydration times between 800 and 1500 days, and the samples were analyzed by micro-focus X-ray Computer Tomography (?CT) and by Environmental Scanning Electron Microscopy (ESEM). The complete set of data enabled a consistent interpretation of the observations and lead to an improved understanding of the phenomenology of the water uptake, swelling, and NaNO3 leaching in restricted swelling conditions. Under the studied conditions, the bituminous matrix surrounding the NaNO3 crystals and pores with NaNO3 solution behaved as a highly efficient semi-permeable membrane, i.e. osmotic processes occurred. In the main part of the leached layers, a high average NaNO3 concentration and related to this a high osmotic pressure prevailed, explaining why in the studied range the swelling was not measurably affected by the counterpressure. At the interface with the stainless steel filters, a low permeable re-compressed bitumen layer was formed, contributing to the slow release of NaNO3 compared to the water uptake rate. A fully coupled Chemo-Hydro-Mechanical (CHM) constitutive model has been developed that integrates the key processes involved and that reproduces satisfactorily the results; this is presented in another work. Combination of the experimental and the modelling study allow to conclude that under semi-confined conditions the swelling of the bituminized waste, and its evolution with time, is the result of several transient processes (salts dissolution, diffusion of salts and water, advection, creep, involving a low permeability material with evolving thickness and properties) that moreover are non-linear and strongly coupled.

  12. Osmosis-induced swelling of Eurobitum bituminized radioactive waste in constant total stress conditions

    Valcke, E., E-mail: evalcke@sckcen.b [Waste and Disposal Expert Group, Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, 2400 Mol (Belgium); Marien, A.; Smets, S. [Waste and Disposal Expert Group, Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, 2400 Mol (Belgium); Li, X., E-mail: xli@sckcen.b [EIG EURIDICE, Boeretang 200, 2400 Mol (Belgium); Mokni, N., E-mail: nadia.mokni@upc.ed [Department of Geotechnical Engineering and Geosciences, Universidad Politecnica de Catalunya (UPC) (Spain); Olivella, S., E-mail: sebastia.olivella@upc.ed [Department of Geotechnical Engineering and Geosciences, Universidad Politecnica de Catalunya (UPC) (Spain); Sillen, X., E-mail: x.sillen@nirond.b [ONDRAF/NIRAS, Kunstlaan 14, 1210 Brussel (Belgium)

    2010-11-30

    In geological disposal conditions, contact of Eurobitum bituminized radioactive waste, which contains high amounts of the hygroscopic and highly soluble NaNO{sub 3}, with groundwater will result in water uptake and swelling of the waste, and in subsequent leaching of the embedded NaNO{sub 3} and radionuclides. The swelling of and the NaNO{sub 3} leaching from non-radioactive Eurobitum samples, comprised between two stainless steel filters and in contact with 0.1 M KOH, was studied in restricted (semi-confined) swelling conditions, i.e. under a constant total stress, or counterpressure, of 2.2, 3.3, or 4.4 MPa (i.e. oedometer conditions). Four tests were stopped after hydration times between 800 and 1500 days, and the samples were analyzed by micro-focus X-ray Computer Tomography ({mu}CT) and by Environmental Scanning Electron Microscopy (ESEM). The complete set of data enabled a consistent interpretation of the observations and lead to an improved understanding of the phenomenology of the water uptake, swelling, and NaNO{sub 3} leaching in restricted swelling conditions. Under the studied conditions, the bituminous matrix surrounding the NaNO{sub 3} crystals and pores with NaNO{sub 3} solution behaved as a highly efficient semi-permeable membrane, i.e. osmotic processes occurred. In the main part of the leached layers, a high average NaNO{sub 3} concentration and related to this a high osmotic pressure prevailed, explaining why in the studied range the swelling was not measurably affected by the counterpressure. At the interface with the stainless steel filters, a low permeable re-compressed bitumen layer was formed, contributing to the slow release of NaNO{sub 3} compared to the water uptake rate. A fully coupled Chemo-Hydro-Mechanical (CHM) constitutive model has been developed that integrates the key processes involved and that reproduces satisfactorily the results; this is presented in another work. Combination of the experimental and the modelling study allow to conclude that under semi-confined conditions the swelling of the bituminized waste, and its evolution with time, is the result of several transient processes (salts dissolution, diffusion of salts and water, advection, creep, involving a low permeability material with evolving thickness and properties) that moreover are non-linear and strongly coupled.

  13. Prospective study in the management of high-dose radioactive iodine therapy induced gastritis

    Full text: Gastritis is simply defined as inflammation of the gastric mucosa. In post-RAI patients, this is one of the most common complications that are encountered. Some patients may even require repetitive administration of high doses of radioactive iodine (I-131). Small doses of radiation (up to 1500 R) cause reversible mucosal damage, whereas higher radiation doses cause irreversible damage with atrophy and ischemic-related ulceration. Reversible changes consist of degenerative changes in epithelial cells and nonspecific chronic inflammatory infiltrate in the lamina propria. Higher amounts of radiation cause permanent mucosal damage, with atrophy of fundic glands, mucosal erosions, and capillary hemorrhage. Associated submucosal endarteritis results in mucosal ischemia and secondary ulcer development. Recurrent gastritis, if left untreated, may be a predisposing factor for gastric malignancy. Methods:A total of thirty post-RAI subjects were evaluated for signs and symptoms of gastritis and were divided into 3 groups which were given drugs for gastritis (H2-receptor antagonist, proton pump inhibitor, and sucralfate). Survey forms were distributed to evaluate the presence of nausea, vomiting, epigastric pain (graded according to severity of pain), and gastrointestinal bleeding. Results were tallied accordingly. Results and Discussion: In a total of 3 subjects who were given sucralfate, all of them did not experience any nausea and vomiting. One subject experienced mild epigastric discomfort and another subject was able to experience a non-specific symptom of abdominal bloatedness. (Note: Subjects are still for completion) In theory, radiation irritates the mucosa causing inflammation and mucosal damage which is further irritated by gastric acid secretion. The administration of H2-receptor blockers and proton pump inhibitors only inhibit gastric acid secretion while existing inflammation of mucosa due to high doses of radiation is left untreated. However, sucralfate may selectively bind to the damaged mucosa and act as a barrier to acid, pepsin and bile. Conclusion: Promising results are noted, however, completion of subjects is still warranted to further strengthen the study. Aside from being the most common complication of high dose and repetitive radioactive iodine administration, management of gastritis in post-RAI patients is valuable because of the possible sequelae of gastrointestinal bleeding and/or gastric malignancy. (author)

  14. Benchmark studies of induced radioactivity produced in LHC materials, part I: Specific activities

    Samples of materials which will be used in the LHC machine for shielding and construction components were irradiated in the stray radiation field of the CERN-EU high-energy reference field facility. After irradiation, the specific activities induced in the various samples were analysed with a high-precision gamma spectrometer at various cooling times, allowing identification of isotopes with a wide range of half-lives. Furthermore, the irradiation experiment was simulated in detail with the FLUKA Monte Carlo code. A comparison of measured and calculated specific activities shows good agreement, supporting the use of FLUKA for estimating the level of induced activity in the LHC. (authors)

  15. Induced polarisation and the assessment of sorption/diffusion at radioactive waste repository sites

    Induced polarisation is a geophysical technique used in mineral exploration in search of metallic ore deposits. Clay minerals also polarise when subjected to an electric current, although the mechanism differs from that of metallic bodies, and involves, amongst other properties, the clay mineral species, the interlayer spacing of the clay, and the nature and abundance of mobile ions in the pore fluid. As a result, it was proposed that induced polarisation of clays could be used as a method for determining their permeability and diffusivity. The work carried out in developing experimental procedures, and evaluating the feasibility of the proposal is presented in this report. (author)

  16. Artificial forest restoration in the French Massif Central using alternative methods to control grass-induced competition

    Provendier, D.; Balandier, P.

    2004-01-01

    For the last decades and particularly after the windstorm of 1999 which destroyed thousands of ha of even-aged monospecific coniferous area stands (Picea abies, Pinus sylvestris), efforts have been made in French Massif Central to restore mountain forest with broadleaved trees. In such area, natural regeneration of broadleaved forest is often compromised by the absence of parent trees in the vicinity and resorting to artificial regeneration is needed. After disturbances such as windstorm, a ...

  17. Ablation from artificial or laser-induced crater surfaces of silver by laser irradiation at 355 nm

    Toftmann, B.; Schou, Jrgen; Larsen, N.B.

    The angular distribution of laser ablated particles from silver irradiated at 355 nm has been studied. The angular distribution from craters prepared by more than 10(4) shots exhibits only minor changes compared with that from a nonirradiated target. The distribution from artificial cylindrical c...... craters of a depth comparable to the laser spot dimensions is about one order of magnitude smaller at large exit angles than that from a flat target....

  18. Artificial Reefs

    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...

  19. Artificial sweeteners

    Raben, Anne Birgitte; Richelsen, Bjrn

    2012-01-01

    PURPOSE OF REVIEW: 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. RECENT FINDINGS: Short-term intervention studies have shown divergent results wrt appetite...... regulation, but overall artificial sweeteners cannot be claimed to affect hunger. Data from longer term intervention studies are scarce, but together they point toward a beneficial effect of artificial sweeteners on energy intake, body weight, liver fat, fasting and postprandial glycemia, insulinemia, and...

  20. Natural - synthetic - artificial!

    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....

  1. Effect of atropine and gammahydroxybutyrate on ischemically induced changes in the level of radioactivity in [3H]inositol phosphates in gerbil brain in vivo

    Brain ischemia in gerbils was induced by ligation of both common carotid arteries for 1 min or 10 min. Sham-operated animals served as controls. Intracerebral injection of [3H]inositol into gerbil brain 16 hr before ischemic insult resulted in equilibration of the label between inositol lipids and water-soluble inositol phosphate. A short ischemic period (1 min) resulted in a statistically significant increase in the radioactivity of inositol triphosphate (IP3) and inositol monophosphate (IP), by about 48% and 79%, respectively, with little change in that of the intermediate inositol biphosphate (IP2), which increased by about 16%. When the ischemic period was prolonged (10 min), an increase in the radioactivity of inositol monophosphate exclusively, by about 84%, was observed. The level of radioactivity in inositol phosphates IP2 and IP3 decreased by about 50%, probably as a consequence of phosphatase activation by the ischemic insult. The agonist of the cholinergic receptor, carbachol, injected intracerebrally (40 micrograms per animal) increased accumulation of radioactivity in all inositol phosphates. The level of radioactivity in IP3, IP2, and IP was elevated by about 40, 23, and 147%, respectively. The muscarinic cholinergic antagonist, atropine, injected intraperitoneally in doses of 100 mg/kg body wt. depressed phosphoinositide metabolism in control animals. The level of radioactivity in water-soluble inositol metabolites in the brain of animals pretreated with atropine was evidently about 32% lower than in untreated animals. Pretreatment with atropine decreased the radioactivity of all inositol phosphates in the brain of animals subjected to 1-min ischemia and the radioactivity of IP in the case of 10-min brain ischemia

  2. Validation of induced radioactivity calculations for candidate fusion materials through measurements in a graphite-centered assembly

    Induced radioactivity measurements were carried out jointly by the USA and Japan in a graphite-centered assembly, in the framework of ITER Task T-218 entitled 'Shielding Blanket Neutronics Experiments'. An intense, accelerator-based D-T rotating target neutron source JAERI, with a nominal intensity of 5 x 1012 s-1, was used. Two locations, providing different neutron energy spectra, were chosen for irradiating samples of a range of materials of interest to ITER. Three independent experimental campaigns were conducted so as to accommodate a large number of samples, on one hand, and as many short and long half-life products as possible, on the other. The total neutron fluence ranged from 4.7 x 1011 to 1.5 x 1014 n cm-2. Altogether, samples of Mg, Al, SiO2, Ti, V, Cr, Mn, Fe, Co, Ni, FH82 steel, SS316LN steel (ITER grade), Cu, Zn, KCl, Zr, Nb, Mo, Ag, ln, Sn, Dy, Ta, Hf, Re, Au, Ir, and Pb were irradiated. The irradiated samples were cooled for variable periods ranging from 30 s to 250 days before their decay gamma-ray spectra were counted on high purity intrinsic germanium detectors. The half lives of the observed radioisotopes have ranged from 18.7 s (46mSc from Ti) to 5.3 years (60Co from Ni). The neutron energy spectra for the two locations were calculated using Monte Carlo code MCNP with FENDL-1 and ENDF/B-VI data libraries. The analysis of isotopic activities, expressed in Bq cc-1, of the irradiated materials has been carried out using REAC-3 radioactivity code, with FENDL-2A and FENDL-1A activation cross-section and decay data libraries. Typically, C/E lies in a band of 0.5-1.5 for the results being reported. (orig.)

  3. Development of the precise measurement method for gamma-ray energy of neutron induced radioactive nuclides

    Goal of the research is to develop a new energy calibration method to perform precise measurement of photon energy by gamma-ray spectrometry. Here, we regard reference standard energies to be those of photon of radioactive isotopes measured basing on a laser wavelength of 86Kr (606 nm) together with energy-wavelength conversion factor E? = 1.239 842 44 x 10-6 eV m 0.03 ppm (CODATA 1986). As such the reference standard we use 192Ir isotope. Deviation of photon energy values between data obtained by photon spectrometry, i.e., the decay gamma-ray analysis and the prompt gamma-ray analysis with Ge or Ge(Li) detectors, and those obtained by crystal diffraction spectrometry, has led that the 'conventional' method of energy calibration for the photon spectrometry is not adequate to the precise energy assignment. A 'new' method has solved this problem by introducing the concept of an instrument function, which is the transfer function between an input signal-shape function and an output (measured) signal-shape function, as summarized in reference 1. Present status of photon energy values has been examined for the nuclear-decay gamma-rays, the nuclear excitation gamma-rays and the mesonic-atom X-rays. At the previous stage of research we evaluated that a commonly-used internal standard method, mainly used for activation analysis study, was inadequate for the precise measurement of photon energy, so far as we use base subtraction method. In the present study, we examined the cause of the inadequacy of a base-subtraction method for obtaining the photopeak line shape for the precise energy measurement. (author)

  4. Thermally induced motion of marine sediments resulting from disposal of radioactive wastes

    Coupled creep and heat transfer calculations have been performed to assess the sensitivity of heat load, viscosity, and canister density on the motion of waste canisters buried in marine sediments. Results indicate that no upward movement is predicted for heat loads remaining within the metallurgical and geochemical constraints placed on the temperature of sediments near the canister for the times analyzed. Upward movement of the canister is again not observed in calculations involving reasonable variations of the sediment viscosity and canister density. Maximum effective deviatoric stress levels due to thermally induced differential body forces are significantly less than the sediment's short term peak strength

  5. Induced radioactivity of materials by stray radiation fields at an electron accelerator

    Samples of soil, water, aluminum, copper and iron were irradiated in the stray radiation field generated by the interaction of a 28.5 GeV electron beam in a copper-dump in the Beam Dump East facility at the Stanford Linear Accelerator Center. The specific activity induced in the samples was measured by gamma spectroscopy and other techniques. In addition, the isotope production in the samples was calculated with detailed Monte Carlo simulations using the FLUKA code. The calculated activities are compared to the experimental values and differences are discussed

  6. Artificial Blood

    Umit Yasar

    2012-04-01

    Full Text Available The problems and additional cost factor involved in collecting and storing human blood, as well as the pending worldwide shortages are the main driving forces in the development of blood substitutes. Studies on artificial blood basically aim to develop oxygen carrying compounds, produce stem cell-based erythrocyte cells in vitro and, implement the functions and movements of natural hemoglobin molecules found in erythrocyte cells through artificial erythrocyte cells. Consequently, major areas of research in artificial blood studies are haemoglobin-based oxygen carriers, perfluorochemicals, respirocytes and stem cells. Even though these artificial erythrocyte cells do not qualify as perfect red blood cell substitutes yet, they have many potential clinical and non clinical uses. Studies are being carried out on the elimination of side effects of blood substitutes and extensive clinical trials are being conducted to test their safety and efficacy. Artificial blood substitutes could only be used clinically for patient management following clinical trials and approvals, and will be the ultimate global solution to the problems associated with donor scarcity, blood collection and transfusion-mediated diseases. [Archives Medical Review Journal 2012; 21(2.000: 95-108

  7. Artificial noses.

    Stitzel, Shannon E; Aernecke, Matthew J; Walt, David R

    2011-08-15

    The mammalian olfactory system is able to detect many more odorants than the number of receptors it has by utilizing cross-reactive odorant receptors that generate unique response patterns for each odorant. Mimicking the mammalian system, artificial noses combine cross-reactive sensor arrays with pattern recognition algorithms to create robust odor-discrimination systems. The first artificial nose reported in 1982 utilized a tin-oxide sensor array. Since then, however, a wide range of sensor technologies have been developed and commercialized. This review highlights the most commonly employed sensor types in artificial noses: electrical, gravimetric, and optical sensors. The applications of nose systems are also reviewed, covering areas such as food and beverage quality control, chemical warfare agent detection, and medical diagnostics. A brief discussion of future trends for the technology is also provided. PMID:21417721

  8. Artificial sweeteners

    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....

  9. From meandering to straight grain boundaries: Improving the structures of artificially-induced grain boundaries in superconducting YBa2Cu3Oy bicrystals

    This paper presents several key aspects of the successful approach to preparing artificially-induced [001] tilt YBa2Cu3Oy (YBCO) grain boundaries (GBs) with uniform, well-defined structures. The authors have compared the structure of GBs produced in thin film bicrystals and bulk bicrystals, respectively. In the YBCO thin film bicrystals prepared by off-axis magnetron sputtering, meandering rather than planar GBs were generally formed due to the three-dimensional island-shaped nucleation and growth of the thin films. Experimentally, using a low film deposition rate has been demonstrated to reduce the magnitude of meander. However, complete elimination of the meandering configuration has not yet been accomplished due to the film growth mechanism. Thus, the authors have developed a dual-seeded-melt-texture process to produce uniform, planar GBs in [001] tilt YBCO bulk bicrystals. Transmission electron microscopy (TEM) studies revealed GBs with a remarkably planar configuration on both micro and nano-meter scales, demonstrating that simpler, meander-free GB microstructures with well defined [001] tilt angle have been successfully produced compared to those formed in bicrystal thin films. The high reproducibility, excellent stability and well controlled GB orientations have established the dual-seeded-melt-texture process as a reliable technique for engineering artificial GBs for the purpose of systematic studies of GB properties and allow for more insightful measurements of transport properties across individual GBs

  10. Artificial intelligence

    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

  11. Artificial Intelligence

    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

  12. Radioactivity and Environment

    Radioactivity is one of the most studied natural phenomena. Most of irradiation suffered by the human being is produced by natural sources. The second source in order of importance is nuclear medicine. The average level of radiation received by the man is 2.4 mSv/year and this value can be modified naturally in 20-30%. The author provides a review on radioactivity sources like natural (cosmic rays, extraterrestrial radiation, internal earth radiation, radon) and artificial (Nuclear explosions, professional exposure, nuclear medicine, nuclear power plants and accidents)

  13. Use of artificial tracers in hydrology

    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 99Mo-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

  14. Artificial radioactive tracers: a tool for oceanography

    In marine hydrodynamic, use of 125Sb as tracer and a two stages coprecipitation analysis process allows to study water motion in the Channel and in the seas of the north east of Europe from effluents of La Hague (France) reprocessing plant. Other tracers may be used: 137Cs coming principally from Sellafield (United Kingdom), and 134Cs coming from Chernobyl accident. (A.B.). 15 refs., 8 figs., 5 tabs

  15. Artificial photosynthesis

    Andrew C. Benniston; Anthony Harriman

    2008-01-01

    We raise here a series of critical issues regarding artificial photosynthesis with the intention of increasing awareness about what needs to be done to bring about a working prototype. Factors under consideration include energy and electron transfers, coupled redox reactions, repair mechanisms, and integrated photosystems.

  16. Residual neutron-induced radio-activities in samples exposed in Hiroshima

    Among the radionuclides that have been detected in materials exposed to the nuclear explosions in Hiroshima and Nagasaki, 152Eu, 154Eu, and 60Co can be measured even today by using high-sensitivity gamma-ray counting techniques. Since 152Eu, 154Eu and 60Co are produced principally from stable isotopes of europium and cobalt by neutron capture reactions, they are useful radionuclides for checking the validity of a series of computer calculations employed for the reassessment of atomic bomb neutron dosimetry in Hiroshima and Nagasaki (chapter 5). The use of 152Eu, 154Eu and 60Co for the reassessment of A-bomb neutron dosimetry, however, has been limited by the following difficulties: 1) today, these radionuclides are found only at extremely low concentrations in materials exposed to the nuclear explosions; and 2) the neutrons that induced these radionuclides were thermal and epithermal, while the neutron dose received in Hiroshima and Nagasaki is attributable mainly to fast neutrons. In the present work, for the purpose of obtaining information on fast neutron fluence in Hiroshima, the depth distribution of the activity of 152Eu to the abundance of stable Eu, 152Eu/Eu, was studied, using a thick sample exposed to the Hiroshima A-bomb. Furthermore, a proposal to analyze thermal and epithermal neutron fluences from a set of data of 152Eu/Eu, 154Eu/Eu, and 60Co/Co was examined, using samples exposed to the Hiroshima A-bomb in the vicinity of the hypocenter. For the reliable and simultaneous determination of 152Eu/Eu, 154Eu/Eu and 60Co/Co, chemical extraction of Eu and Co from the exposed sample was studied. The procedure to prepare samples enriched in Eu and Co was also applied to samples exposed to the Hiroshima A-bomb at locations 1300 m from the hypocenter, because determination of 152Eu is extremely difficult without chemical enrichment of Eu from samples exposed to the A-bomb at locations greater than 1000 m from the hypocenter

  17. Radioactive surveillance in peruvian foods

    The concentrations of radionuclides in some Peruvian foodstuffs have been measured. The results of this study can be considered as a first step towards calculating the baseline levels of radioactivity in foodstuffs from Peru. The overall intake of Cs-137 is quite low and no significant radionuclide contamination was found. Therefore the results shows that, between 1990 and 2006, consumers' exposure to artificially produced radioactivity via the food chain, is below the peruvian annual dose limit to members of the public of 1 mSv (millisievert) for all artificial sources of radiation. (author)

  18. Transportation of radioactive elements

    The production and marketing of artificial radioactive elements engaged in by the 'Office des Rayonnements Ionisants' requires the use of specially designed packagings and assorted means of transport. The authors begin by describing the different kinds of products involved and the forms of packagings needed, and go on to discuss the various means of transport used, underlining the fact that, in terms of number and gravity, the incidents that have occurred to date have indeed been few and far between

  19. Monitoring of peptide induced disruption of artificial lipid membrane constructed on boron-doped nanocrystalline diamond by electrochemical impedance spectroscopy

    Petrak, Vaclav; Grieten, Lars; Taylor, Andrew; Fendrych, Frantisek; Ledvina, Miroslav; Janssens, Stoffel D.; Nesladek, Milos; Haenen, Ken; Wagner, Patrick Hermann

    2011-01-01

    With the rise of antibiotic resistance of pathogenic bacteria there is an increased demand for monitoring of the functionality of bacteria membranes, whose disruption can be induced by peptide lipid interactions. In this work we attempt to monitor formation and subsequent peptide induced disruption of supported lipid membranes (SLBs) on boron-doped nanocrystalline diamond (B-NCD). Electrochemical Impedance Spectroscopy (EIS) was used to study in situ changes related to lipid membrane formatio...

  20. Radioactivity [includes radioactivity levels

    The Environmental Digest for Wales is prepared on a regular basis by the Welsh Office and brings together data on the Welsh environment from a number of sources. Most of the information contained in the tables is collected as part of continuous monitoring programmes and will be updated in future editions. Some tables contain information collected only once as part of a survey or study, and will not be included in future volumes of the series. The section on Radioactivity includes tables of concentration in air, rainwater, milk, fish and gives details of the liquid radioactive wastes discharged from Welsh nuclear power stations (at Wylfa and Trawsfynydd) and the gamma dose rates around Welsh nuclear power stations. An appendix includes a glossary of terms used, the units of radioactivity and a list of radionuclides present in the environment. (author)

  1. Artificial Intelligence.

    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. PMID:26957450

  2. Geochemical Effects of Induced Stream-Water and Artificial Recharge on the Equus Beds Aquifer, South-Central Kansas, 1995-2004

    Schmidt, Heather C. Ross; Ziegler, Andrew C.; Parkhurst, David L.

    2007-01-01

    Artificial recharge of the Equus Beds aquifer is part of a strategy implemented by the city of Wichita, Kansas, to preserve future water supply and address declining water levels in the aquifer of as much as 30 feet caused by withdrawals for water supply and irrigation since the 1940s. Water-level declines represent a diminished water supply and also may accelerate migration of saltwater from the Burrton oil field to the northwest and the Arkansas River to the southwest into the freshwater of the Equus Beds aquifer. Artificial recharge, as a part of the Equus Beds Ground-Water Recharge Project, involves capturing flows larger than base flow from the Little Arkansas River and recharging the water to the Equus Beds aquifer by means of infiltration or injection. The geochemical effects on the Equus Beds aquifer of induced stream-water and artificial recharge at the Halstead and Sedgwick sites were determined through collection and analysis of hydrologic and water-quality data and the application of statistical, mixing, flow and solute-transport, and geochemical model simulations. Chloride and atrazine concentrations in the Little Arkansas River and arsenic concentrations in ground water at the Halstead recharge site frequently exceeded regulatory criteria. During 30 percent of the time from 1999 through 2004, continuous estimated chloride concentrations in the Little Arkansas River at Highway 50 near Halstead exceeded the Secondary Drinking-Water Regulation of 250 milligrams per liter established by the U.S. Environmental Protection Agency. Chloride concentrations in shallow monitoring wells located adjacent to the stream exceeded the drinking-water criterion five times from 1995 through 2004. Atrazine concentrations in water sampled from the Little Arkansas River had large variability and were at or near the drinking-water Maximum Contaminant Level of 3.0 micrograms per liter as an annual average established by the U.S. Environmental Protection Agency. Atrazine concentrations were much smaller than the drinking-water criterion and were detected at much smaller concentrations in shallow monitoring wells and diversion well water located adjacent to the stream probably because of sorption on aquifer sediment. Before and after artificial recharge, large, naturally occurring arsenic concentrations in the recharge water for the Halstead diversion well and recharge site exceeded the Maximum Contaminant Level of 10 micrograms per liter established by the U.S. Environmental Protection Agency for drinking water. Arsenic and iron concentrations decreased when water was recharged through recharge basins or a trench; however, chemical precipitation and potential biofouling eventually may decrease the artificial recharge efficiency through basins and trenches. At the Sedgwick site, chloride concentrations infrequently exceeded regulatory criteria. Large concentrations of atrazine were treated to decrease concentrations to less than regulatory criteria. Recharge of treated stream water through recharge basins avoids potentially large concentrations of arsenic and iron that exist at the Halstead diversion site. Results from a simple mixing model using chloride as a tracer indicated that the water chemistry in shallow monitoring well located adjacent to the Little Arkansas River was 80 percent of stream water, demonstrating effective recharge of the alluvial aquifer by the stream. Results also indicated that about 25 percent of the water chemistry of the diversion well water was from the shallow part of the aquifer. Additionally, diverting water through a diversion well located adjacent to the stream removed about 75 percent of the atrazine, probably through sorption to aquifer sediment, and decreased the need for additional water treatment to remove atrazine. A flow and solute-transport model was developed using water-level and chloride concentration data to simulate and better evaluate the quantity of stream-water flow to the p

  3. Does Artificial Ascites Induce the Heat-Sink Phenomenon during Percutaneous Radiofrequency Ablation of the Hepatic Subcapsular Area?: an in vivo Experimental Study Using a Rabbit Model

    Kim, Young Sun; Rhim, Hyun Chul; Choi, Dong Il; Lim, Hyo K. [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2009-02-15

    To evaluate the effect of the heat-sink phenomenon induced by artificial ascites on the size of the ablation zone during percutaneous radiofrequency (RF) ablation of the hepatic subcapsular area in an in vivo rabbit model. A total of 21 percutaneous rabbit liver RF ablations were performed with and without artificial ascites (5% dextrose aqueous solution). The rabbits were divided into three groups: a) control group (C, n = 7); b) room temperature ascites group (R, n = 7); and c) warmed ascites group (W, n = 7). The tip of a 1 cm, internally cooled electrode was placed on the subcapsular region of the hepatic dome via ultrasound guidance, and ablation was continued for 6 min. Changes in temperature of the ascites were monitored during the ablation. The size of the ablation zones of the excised livers and immediate complications rates were compared statistically between the groups (Mann-Whitney U test, Kruskal-Wallis test, linear-by-linear association, p = 0.05). One rabbit from the 'W' group expired during the procedure. In all groups, the ascites temperatures approached their respective body temperatures as the ablations continued; however, a significant difference in ascites temperature was found between groups 'W' and 'R' throughout the procedures (39.2+- 0.4 .deg. C in group W and 33.4+-4.3 .deg. C in group R at 6 min, p = 0.003). No significant difference was found between the size of the ablation zones (782.4+-237.3 mL in group C, 1,172.0+-468.9 mL in group R, and 1,030.6+-665.1 mL in group W, p = 0.170) for the excised liver specimens. Diaphragmatic injury was identified in three of seven cases (42.9%) upon visual inspection of group 'C' rabbits (p = 0.030). Artificial ascites are not likely to cause a significant heat-sink phenomenon in the percutaneous RF ablation of the hepatic subcapsular region

  4. Does Artificial Ascites Induce the Heat-Sink Phenomenon during Percutaneous Radiofrequency Ablation of the Hepatic Subcapsular Area?: an in vivo Experimental Study Using a Rabbit Model

    To evaluate the effect of the heat-sink phenomenon induced by artificial ascites on the size of the ablation zone during percutaneous radiofrequency (RF) ablation of the hepatic subcapsular area in an in vivo rabbit model. A total of 21 percutaneous rabbit liver RF ablations were performed with and without artificial ascites (5% dextrose aqueous solution). The rabbits were divided into three groups: a) control group (C, n = 7); b) room temperature ascites group (R, n = 7); and c) warmed ascites group (W, n = 7). The tip of a 1 cm, internally cooled electrode was placed on the subcapsular region of the hepatic dome via ultrasound guidance, and ablation was continued for 6 min. Changes in temperature of the ascites were monitored during the ablation. The size of the ablation zones of the excised livers and immediate complications rates were compared statistically between the groups (Mann-Whitney U test, Kruskal-Wallis test, linear-by-linear association, p = 0.05). One rabbit from the 'W' group expired during the procedure. In all groups, the ascites temperatures approached their respective body temperatures as the ablations continued; however, a significant difference in ascites temperature was found between groups 'W' and 'R' throughout the procedures (39.2± 0.4 .deg. C in group W and 33.4±4.3 .deg. C in group R at 6 min, p = 0.003). No significant difference was found between the size of the ablation zones (782.4±237.3 mL in group C, 1,172.0±468.9 mL in group R, and 1,030.6±665.1 mL in group W, p = 0.170) for the excised liver specimens. Diaphragmatic injury was identified in three of seven cases (42.9%) upon visual inspection of group 'C' rabbits (p = 0.030). Artificial ascites are not likely to cause a significant heat-sink phenomenon in the percutaneous RF ablation of the hepatic subcapsular region

  5. Processing Semblances Induced through Inter-Postsynaptic Functional LINKs, Presumed Biological Parallels of K-Lines Proposed for Building Artificial Intelligence

    Vadakkan, Kunjumon I.

    2011-01-01

    The internal sensation of memory, which is available only to the owner of an individual nervous system, is difficult to analyze for its basic elements of operation. We hypothesize that associative learning induces the formation of functional LINK between the postsynapses. During memory retrieval, the activation of either postsynapse re-activates the functional LINK evoking a semblance of sensory activity arriving at its opposite postsynapse, nature of which defines the basic unit of internal sensation – namely, the semblion. In neuronal networks that undergo continuous oscillatory activity at certain levels of their organization re-activation of functional LINKs is expected to induce semblions, enabling the system to continuously learn, self-organize, and demonstrate instantiation, features that can be utilized for developing artificial intelligence (AI). This paper also explains suitability of the inter-postsynaptic functional LINKs to meet the expectations of Minsky’s K-lines, basic elements of a memory theory generated to develop AI and methods to replicate semblances outside the nervous system. PMID:21845180

  6. Resistance of Mutants of Sweet Orange Induced by Gamma-rays to Citrus Canker (Xanthomonas citri subsp. citri) Under Artificial Inoculation

    The sweet orange holds great economic and social importance for Brazil, but it is susceptible to citrus canker as is the majority of citrus species. In cases of high incidence, this disease caused by the bacterium Xanthomonas citri subsp. citri can result in great economic damage. More resistant cultivars are the best long-term solution for management of citrus canker and one of the approaches can be the production of mutant plants. In a previous work, several induced mutant clones of sweet orange cv. Pera were selected. They showed a lower intensity of symptoms of citrus canker in leaves and fruits in evaluations under natural incidence of the disease, in the field. The objective of this study is to assess the resistance to citrus canker of six mutant clones of cultivar Pera and control plants (three different varieties), in experiments of artificial inoculation. The parameters evaluated were: incubation period, diameter of the lesions and area under the disease progress curve (AUDPC), in evaluations every 15 days, until the 147th day. Only the clones 9-1, 9-2 and 9-3 showed lower incidence of disease, represented by the longest period of incubation of the disease, smaller diameter of lesion and lower AUDPC, using average data of the three experiments. This study is one of the first reports of success in citrus-induced mutations aimed to obtaining greater resistance to diseases. (author)

  7. Resistance of mutants of sweet orange induced by gamma-rays to citrus canker (Xanthomonas citri subsp. citri) under artificial inoculation

    The sweet oranges have great economic and social importance for Brazil. However, it is susceptible to citrus canker as the majority of citrus species. This disease is caused by Xanthomonas citri subsp. citri, bacteria that in case of high incidence can result in great economic damage. More resistant cultivars are the best long-term solution for management of citrus canker and one of the approaches can be the production of mutant plants. In a previous work, several induced mutant clones of sweet orange cv. Pera were selected. They showed lower intensity of symptoms of citrus canker in leaves and fruits in evaluations under natural incidence of the disease, in the field. The objective of this study is to assess the resistance to citrus canker of six mutant clones of cultivar Pera and control plants (three different varieties), in experiments of artificial inoculation. The parameters evaluated were: incubation period, diameter of the lesions and area under the disease progress curve (AUDPC), in evaluations every 15 days, until the 147th day. Only the clones 9-1, 9-2 and 9-3 showed lower incidence of disease, represented by the longest period of incubation of the disease, smaller diameter of lesion and lower AUDPC, in all experiment and using average data of the three experiments. This study is one of the first reports of success in citrus induced mutations aimed to obtaining greater resistance to diseases. (author)

  8. Predicting typhoon-induced storm surge tide with a two-dimensional hydrodynamic model and artificial neural network model

    Chen, W.-B.; Liu, W.-C.; Hsu, M.-H.

    2012-12-01

    Precise predictions of storm surges during typhoon events have the necessity for disaster prevention in coastal seas. This paper explores an artificial neural network (ANN) model, including the back propagation neural network (BPNN) and adaptive neuro-fuzzy inference system (ANFIS) algorithms used to correct poor calculations with a two-dimensional hydrodynamic model in predicting storm surge height during typhoon events. The two-dimensional model has a fine horizontal resolution and considers the interaction between storm surges and astronomical tides, which can be applied for describing the complicated physical properties of storm surges along the east coast of Taiwan. The model is driven by the tidal elevation at the open boundaries using a global ocean tidal model and is forced by the meteorological conditions using a cyclone model. The simulated results of the hydrodynamic model indicate that this model fails to predict storm surge height during the model calibration and verification phases as typhoons approached the east coast of Taiwan. The BPNN model can reproduce the astronomical tide level but fails to modify the prediction of the storm surge tide level. The ANFIS model satisfactorily predicts both the astronomical tide level and the storm surge height during the training and verification phases and exhibits the lowest values of mean absolute error and root-mean-square error compared to the simulated results at the different stations using the hydrodynamic model and the BPNN model. Comparison results showed that the ANFIS techniques could be successfully applied in predicting water levels along the east coastal of Taiwan during typhoon events.

  9. Ambient radioactivity levels and radiation doses. Annual report 2013

    The report on environmental radioactivity and radiation exposure 2013 includes data concerning the following issues: sources of natural and artificial radioactivity, radon in buildings, radioactive materials in construction materials and industrial products, nuclear weapon tests, the consequences of reactor accidents in Chernobyl and Fukushima, nuclear facilities, occupational exposure, radiation exposure from medical applications, handling of radioactive materials in research and technology, radioactive wastes, radiation accidents and specific incidents.

  10. Psychologically induced cooling of a specific body part caused by the illusory ownership of an artificial counterpart

    Moseley, G. Lorimer; Olthof, Nick; Venema, Annemeike; Don, Sanneke; Wijers, Marijke; Gallace, Alberto; Spence, Charles

    2008-01-01

    The sense of body ownership represents a fundamental aspect of our self-awareness, but is disrupted in many neurological, psychiatric, and psychological conditions that are also characterized by disruption of skin temperature regulation, sometimes in a single limb. We hypothesized that skin temperature in a specific limb could be disrupted by psychologically disrupting the sense of ownership of that limb. In six separate experiments, and by using an established protocol to induce the rubber h...

  11. Environmental radioactivity in the antarctic station

    Study about environmental radioactivity in the Peruvian antarctic station Machu Pichu they were carried out during the last three periods to the southern summer. The objective of the project it is to evaluate environmental component in order to elaborate a study it base on the levels background radioactivity and artificial in the antarctic region

  12. Factors influencing pregnancy per artificial insemination in repeat-breeder cows induced to ovulate with a CIDR-based protocol.

    Mellado, M; Zuñiga, A; Veliz, F G; de Santiago, A; Garcia, J E; Mellado, J

    2012-10-01

    The aim of this study was to determine, using multiple logistic models, factors affecting pregnancy per AI (P/AI) following fixed-time artificial insemination (FTAI) in repeat breeders cows (RBC) treated with rbST throughout lactation. 498 RBC received a CIDR device and 100μg of GnRH on day 0. CIDR removal and PGF(2α) (25mg) treatment were done concurrently on day 7. Estradiol benzoate (EB, 1mg) was injected on day 8 and GnRH on day 9; cows were inseminated 16-20h later. Cows with an average milk protein <3% were 43% more likely (P<0.05) to become pregnant at FTAI than cows with milk protein ≥3%. Cows with <6 services had significantly increased chances of becoming pregnant than cows with ≥6 services at FTAI (P/AI 36 vs. 27%; P<0.05). CIDR-treated cows with less than three lactations were 1.7 times more likely (P/AI 35 vs. 21%; P<0.05) to become pregnant than cows in third or greater lactation. Cows with peak milk yields lower than 55kg were 1.5 times more likely to get pregnant than cows with peak milk yields greater than 55kg (P/AI 37 vs. 28%; P<0.05). P/AI was lower (30 vs. 35%; P<0.01) for cows with dry periods <62 days than cows with dry periods ≥62 days. Cows subjected to FTAI with a temperature-humidity index (THI) <76 were 45% more likely (P<0.05) to become pregnant than cows inseminated at a THI≥76. It was concluded that an acceptable proportion (32%) of RBC can become pregnant with the protocol used in the present study. Also, subfertility in CIDR-treated cows was associated with high peak yields, high milk protein, increased service, increased lactation, high THI at AI and short dry periods. PMID:22917878

  13. Radioactive contamination of the environment

    The present work opens a series of publications on the results of long-term observations of environmental radioactive contamination in the environs of Leningrad. In the first issue the technique for determination and the results of observations of surface contamination due to artificial radioactive aerosols are presented for 1959-1977. It is shown that the main source of ground air contamination in Leningrad is the global of fission products resulting from nuclear explosions in the atmosphere. The results presented in this work can be used for estimation of levels and isotope composition of radioactive contamination in the temperature zone of the northern hemisphere

  14. Osmosis-induced water uptake by Eurobitum bituminized radioactive waste and pressure development in constant volume conditions

    Marieen, A., E-mail: amarien@sckcen.be [Waste and Disposal Expert Group, Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, 2400 Mol (Belgium); Mokni, N., E-mail: Nadia.mokni@upc.edu [Department of Geotechnical Engineering and Geosciences, Universidad Politecnica de Catalunya (UPC), Calle Gran Capitan, s/n, Edificio C-1, 08034 Barcelona (Spain); Valcke, E. [Waste and Disposal Expert Group, Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, 2400 Mol (Belgium); Olivella, S. [Department of Geotechnical Engineering and Geosciences, Universidad Politecnica de Catalunya (UPC), Calle Gran Capitan, s/n, Edificio C-1, 08034 Barcelona (Spain); Smets, S. [Waste and Disposal Expert Group, Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, 2400 Mol (Belgium); Li, X., E-mail: xli@sckcen.be [EIG EURIDICE, Boeretang 200, 2400 Mol (Belgium)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer The water uptake by Eurobitum is studied to judge the safety of geological disposal. Black-Right-Pointing-Pointer High pressures of up to 20 MPa are measured in constant volume water uptake tests. Black-Right-Pointing-Pointer The morphology of leached Eurobitum samples is studied with {mu}CT and ESEM. Black-Right-Pointing-Pointer The observations are reproduced by an existing CHM formulation for Eurobitum. - Abstract: The chemo-hydro-mechanical (CHM) interaction between swelling Eurobitum radioactive bituminized waste (BW) and Boom Clay is investigated to assess the feasibility of geological disposal for the long-term management of this waste. These so-called compatibility studies include laboratory water uptake tests at Belgian Nuclear Research Center SCK-CEN, and the development of a coupled CHM formulation for Eurobitum by the International Center for Numerical Methods and Engineering (CIMNE, Polytechnical University of Cataluna, Spain). In the water uptake tests, the osmosis-induced swelling, pressure increase and NaNO{sub 3} leaching of small cylindrical BW samples (diameter 38 mm, height 10 mm) is studied under constant total stress conditions and nearly constant volume conditions; the actual geological disposal conditions should be intermediate between these extremes. Two nearly constant volume tests were stopped after 1036 and 1555 days to characterize the morphology of the hydrated BW samples and to visualize the hydrated part with microfocus X-ray Computer Tomography ({mu}CT) and Environmental Scanning Electron Microscopy (ESEM). In parallel, a coupled CHM formulation is developed that describes chemically and hydraulically coupled flow processes in porous materials with salt crystals, and that incorporates a porosity dependent membrane efficiency, permeability and diffusivity. When Eurobitum BW is hydrated in (nearly) constant volume conditions, the osmosis-induced water uptake results in an increasing pressure to values that can be (in theory) as high as 42.8 MPa, being the osmotic pressure of a saturated NaNO{sub 3} solution. After about four years of hydration in nearly constant volume water uptake tests, pressures up to 20 MPa are measured. During this hydration period only the outer layers with a thickness of 1-2 mm were hydrated (as derived from {mu}CT and ESEM analyses), and only about 10-20% of the initial NaNO{sub 3} content was released by the samples. In the studied test conditions, the rates of water uptake and NaNO{sub 3} leaching are low because of the low porosity, and thus low permeability, of the hydrated BW samples in combination with a highly efficient semi-permeable bitumen membrane. In contrast to the hydration in free swelling conditions, the increase in porosity is limited by the high pressures in the nearly constant volume tests. Furthermore, at the interface with the stainless steel filters, a low permeable re-compressed bitumen layer is formed, as observed on the ESEM images. The experimental results of pressure increase and NaNO{sub 3} leaching, as well as observations on {mu}CT and ESEM images (e.g. compression of leached layers, high dissolved NaNO{sub 3} concentration in hydrated BW after about four years), were reproduced rather successfully by the coupled CHM formulation for Eurobitum BW. A long-term model prediction of the evolution of the osmosis-induced pressure in the nearly constant volume tests shows that the pressure would reach a maximal value of about 20 MPa after about 5.5 years, after which the pressure would start to decrease. After 10,000 days ({approx}27 years) the pressure would have decreased to a value of {approx}2 MPa.

  15. Osmosis-induced water uptake by Eurobitum bituminized radioactive waste and pressure development in constant volume conditions

    Mariën, A.; Mokni, N.; Valcke, E.; Olivella, S.; Smets, S.; Li, X.

    2013-01-01

    The chemo-hydro-mechanical (CHM) interaction between swelling Eurobitum radioactive bituminized waste (BW) and Boom Clay is investigated to assess the feasibility of geological disposal for the long-term management of this waste. These so-called compatibility studies include laboratory water uptake tests at the Belgian Nuclear Research Center SCK•CEN, and the development of a coupled CHM formulation for Eurobitum by the International Center for Numerical Methods and Engineering (CIMNE, Polytechnical University of Cataluña, Spain). In the water uptake tests, the osmosis-induced swelling, pressure increase and NaNO3 leaching of small cylindrical BW samples (diameter 38 mm, height 10 mm) is studied under constant total stress conditions and nearly constant volume conditions; the actual geological disposal conditions should be intermediate between these extremes. Two nearly constant volume tests were stopped after 1036 and 1555 days to characterize the morphology of the hydrated BW samples and to visualize the hydrated part with microfocus X-ray Computer Tomography (μCT) and Environmental Scanning Electron Microscopy (ESEM). In parallel, a coupled CHM formulation is developed that describes chemically and hydraulically coupled flow processes in porous materials with salt crystals, and that incorporates a porosity dependent membrane efficiency, permeability and diffusivity. When Eurobitum BW is hydrated in (nearly) constant volume conditions, the osmosis-induced water uptake results in an increasing pressure to values that can be (in theory) as high as 42.8 MPa, being the osmotic pressure of a saturated NaNO3 solution. After about four years of hydration in nearly constant volume water uptake tests, pressures up to 20 MPa are measured. During this hydration period only the outer layers with a thickness of 1-2 mm were hydrated (as derived from μCT and ESEM analyses), and only about 10-20% of the initial NaNO3 content was released by the samples. In the studied test conditions, the rates of water uptake and NaNO3 leaching are low because of the low porosity, and thus low permeability, of the hydrated BW samples in combination with a highly efficient semi-permeable bitumen membrane. In contrast to the hydration in free swelling conditions, the increase in porosity is limited by the high pressures in the nearly constant volume tests. Furthermore, at the interface with the stainless steel filters, a low permeable re-compressed bitumen layer is formed, as observed on the ESEM images. The experimental results of pressure increase and NaNO3 leaching, as well as observations on μCT and ESEM images (e.g. compression of leached layers, high dissolved NaNO3 concentration in hydrated BW after about four years), were reproduced rather successfully by the coupled CHM formulation for Eurobitum BW. A long-term model prediction of the evolution of the osmosis-induced pressure in the nearly constant volume tests shows that the pressure would reach a maximal value of about 20 MPa after about 5.5 years, after which the pressure would start to decrease. After 10,000 days (˜27 years) the pressure would have decreased to a value of ˜2 MPa.

  16. Osmosis-induced water uptake by Eurobitum bituminized radioactive waste and pressure development in constant volume conditions

    Highlights: ► The water uptake by Eurobitum is studied to judge the safety of geological disposal. ► High pressures of up to 20 MPa are measured in constant volume water uptake tests. ► The morphology of leached Eurobitum samples is studied with μCT and ESEM. ► The observations are reproduced by an existing CHM formulation for Eurobitum. - Abstract: The chemo-hydro-mechanical (CHM) interaction between swelling Eurobitum radioactive bituminized waste (BW) and Boom Clay is investigated to assess the feasibility of geological disposal for the long-term management of this waste. These so-called compatibility studies include laboratory water uptake tests at Belgian Nuclear Research Center SCK-CEN, and the development of a coupled CHM formulation for Eurobitum by the International Center for Numerical Methods and Engineering (CIMNE, Polytechnical University of Cataluña, Spain). In the water uptake tests, the osmosis-induced swelling, pressure increase and NaNO3 leaching of small cylindrical BW samples (diameter 38 mm, height 10 mm) is studied under constant total stress conditions and nearly constant volume conditions; the actual geological disposal conditions should be intermediate between these extremes. Two nearly constant volume tests were stopped after 1036 and 1555 days to characterize the morphology of the hydrated BW samples and to visualize the hydrated part with microfocus X-ray Computer Tomography (μCT) and Environmental Scanning Electron Microscopy (ESEM). In parallel, a coupled CHM formulation is developed that describes chemically and hydraulically coupled flow processes in porous materials with salt crystals, and that incorporates a porosity dependent membrane efficiency, permeability and diffusivity. When Eurobitum BW is hydrated in (nearly) constant volume conditions, the osmosis-induced water uptake results in an increasing pressure to values that can be (in theory) as high as 42.8 MPa, being the osmotic pressure of a saturated NaNO3 solution. After about four years of hydration in nearly constant volume water uptake tests, pressures up to 20 MPa are measured. During this hydration period only the outer layers with a thickness of 1–2 mm were hydrated (as derived from μCT and ESEM analyses), and only about 10–20% of the initial NaNO3 content was released by the samples. In the studied test conditions, the rates of water uptake and NaNO3 leaching are low because of the low porosity, and thus low permeability, of the hydrated BW samples in combination with a highly efficient semi-permeable bitumen membrane. In contrast to the hydration in free swelling conditions, the increase in porosity is limited by the high pressures in the nearly constant volume tests. Furthermore, at the interface with the stainless steel filters, a low permeable re-compressed bitumen layer is formed, as observed on the ESEM images. The experimental results of pressure increase and NaNO3 leaching, as well as observations on μCT and ESEM images (e.g. compression of leached layers, high dissolved NaNO3 concentration in hydrated BW after about four years), were reproduced rather successfully by the coupled CHM formulation for Eurobitum BW. A long-term model prediction of the evolution of the osmosis-induced pressure in the nearly constant volume tests shows that the pressure would reach a maximal value of about 20 MPa after about 5.5 years, after which the pressure would start to decrease. After 10,000 days (∼27 years) the pressure would have decreased to a value of ∼2 MPa.

  17. Artificial halos

    Selmke, Markus

    2015-09-01

    Judged by their frequency and beauty, ice halos easily rival rainbows as a prominent atmospheric optics phenomenon. This article presents experimental halo demonstrations of varying complexity. Using a single commercially available hexagonal glass prism, a variety of artificial halos can be simulated. The experiments include laser beam path analysis, a modified classic spinning prism experiment, and a novel Monte-Carlo machine for three-dimensional rotations. Each of these experiments emulates different conditions of certain halo displays, and in combination, they allow a thorough understanding of these striking phenomena.

  18. Decontamination of radioactive cesium in soil

    Agricultural soil containing radioactive cesium was decontaminated using an extraction method involving aqueous potassium solutions. Results demonstrated that the potassium solution could extract radioactive cesium from soil artificially contaminated with 137Cs, although extraction rate decreased as time after contamination increased. However, visual examination of radioactivity distribution in soil samples significantly contaminated by the accident at the Fukushima Daiichi nuclear power plant showed that radioactive cesium also existed as insoluble particles. Therefore, reducing the volume of radioactive wastes generated from soil decontamination requires a physical decontamination method combined with chemical treatment. (author)

  19. Evaluation of genetic variability for heading date and height in triticale obtained by induced mutations and artificial crosses

    The adjustment of adaptive characters such as heading date and height, allows one to arrange successive cultures and to apply efficient agronomic techniques, resulting in productivity increase. Methods that increase genetic variability have great significance in plant breeding, once they amplify the opportunities for selecting superior genotypes. The aim of this study was to evaluate the effect of induced mutations and reciprocal crosses in families segregating for heading date and height and to analyze the correlation between these characters. The populations were obtained from reciprocal crosses and induced mutation with gamma radiation. In the latter, radiation dosages of 0, 5, 10, 20, 40 kR were obtained from exposition to Cobalt - 60. Changes in the mean and variance in two triticale genotypes Triticale BR4 e EMBRAPAI8, were analyzed. The results obtained indicated families with wide segregation patterns for heading date and height and also suggested the possibility to identify families with distinct values compared to the control population for both characters and both genotypes. There was a tendency to reductions in height and increases in heading date for the families evaluated. However, there was not an expressive correlation between heading date and height for the majority of the treatments, therefore allowing the breeder to select plant types adapted to the environment of cultivation. (author)

  20. Environmental radioactivity and drinking water supply. Pt. 4

    The enrichment of radioactivity in the sediments reflects the radioactive pollution of the surface waters. As a result of the good retention capacity of the subsoil and the slow water transport in the unsaturated zone the groundwater was protected against the fallout as expected; even in karst areas only very low concentrations of artificial radioactivity were found in the groundwater. In drinking water no artificial radioactivity was detected in most samples. Only in very few cases the radioactivity of drinking water from surface waters exceeded just the detection limits. The investigations confirmed the previous findings, that the exposition path over drinking water may be neglected compared with other exposition routes. (orig./HP)

  1. Fast identification of biominerals by means of stand-off laser‐induced breakdown spectroscopy using linear discriminant analysis and artificial neural networks

    The goal of this paper is to compare two selected statistical techniques used for identification of archeological materials merely on the base of their spectra obtained by stand-off laser-induced breakdown spectroscopy (stand-off LIBS). Data processing using linear discriminant analysis (LDA) and artificial neural networks (ANN) were applied on spectra of 18 different samples, some of them archeological and some recent, containing 7 types of material (i.e. shells, mortar, bricks, soil pellets, ceramic, teeth and bones). As the input data PCA scores were taken. The intended aim of this work is to create a database for simple and fast identification of archeological or paleontological materials in situ. This approach can speed up and simplify the sampling process during archeological excavations that nowadays tend to be quite damaging and time-consuming. - Highlights: ► We use statistical techniques for identification of archeological materials. ► Input data for LDA and ANN are PC scores counted from stand-off LIBS spectra. ► The method used for identification of archeological materials provides good results. ► After recording more spectra we can get useful tool for rapid analysis in situ.

  2. The development neurotoxicity of ethanol: Cerebral cortical cholinergic alterations induced in artificially reared rats exposed to ethanol during the brain growth spurt

    It is hypothesized that cerebral cortical cholinergic neurotransmitter system alterations are induced by ethanol exposure during the vulnerable period of rapid brain growth. To test this proposal, on postnatal (PN) day 4, male Sprague Dawley rat pups were randomly assigned to either mother raised control (MRC) or artificially reared (AR) experimental groups. AR, ethanol-exposed (EE) pups received a liquid diet containing either 3%, 4%, or 5% (w/v) ethanol, while AR, cup-control (CC) pups isovolumetrically received an isocaloric, glucose-substituted diet. Acute effects of AR (CC vs MRC) and EE (EE vs CC) were determined in groups of pups sacrificed immediately following the termination of AR on PN8. Other groups of neonates were returned to foster dams on PN8 and maternally reared until sacrifice on PN20 to detect persistent or latent alternations. Although AR failed to perturb muscarinic receptor density at either age of assessment, it acutely and persistently decreased receptor affinity for (3H)QNB, and also the activities of both acetylcholinesterase and choline acetyltransferase

  3. Autonomous oscillation/separation of cell density artificially induced by optical interlink feedback as designed interaction between two isolated microalgae chips

    Ozasa, Kazunari; Won, June; Song, Simon; Maeda, Mizuo

    2016-04-01

    We demonstrate a designed interaction between two isolated cell populations of Euglena gracilis and Chlamydomonas reinhardtii, separately confined in two 25-square micro-aquariums of lab-on-chip size. The interaction was realized by interlinking two identical optical feedback systems, which measured the cell distribution. To analyze the cell populations, we measured the cell distribution in the 25 squares and irradiated the cells with a blue light pattern as an external stimulus. The cell distribution dataset was exchanged between the two systems. Governed by a designed interaction algorithm, the feedback systems produced a dynamic blue light illumination pattern that evoked the photophobic responses of both species. We also induced autonomous cell density oscillation and cell distribution separation and clustering, and analyzed how the types and diversities of the photophobic responses affected the oscillation period and separation and clustering. We conclude that artificial interlink feedback is a promising method for investigating diverse cell–cell interactions in ecological communities, and for developing soft-computing applications with living cells.

  4. Airborne measurement of radioactivity

    The German Meteorological Service (Deutscher Wetterdienst, DWD) is responsible for the surveillance of radioactivity in the atmosphere. In case of an radioactive emergency radioactive plumes may be expected in heights up to the tropopause depending on the type of accident. For this reason aircraft measurements are necessary as a supplement to groundbased measuring sites, especially in case of non available details about the source of radioactive release and lack of details about the accident. The authors present an aircraft type Learjet 35A used for localizing radioactive contaminated air masses up to 10,000 m and the measurement of artificial radionuclides on aerosols. For this purpose the aircraft is equipped with an isokinetic high-volume sampler for collection of aerosols on filters outside the pressurized cabin and an onboard gamma spectrometry system with a high purity germanium detector to analyze the interchangeable contaminated filters during flight as well as a dose ratemeter and a GPS (Global Positioning System) for navigation. The collection of gaseous iodine is optional. The meteorological parameters temperature, atmospheric pressure, relative humidity, wind speed and wind direction are determined as well. Resulting data are transmitted by global VHF datalink from the plane to the DWD headquarter and used for verifying the prognosis. (orig.)

  5. Temperature-dependent recombination velocity analysis on artificial small angle grain boundaries using electron beam induced current method

    Kojima, Takuto; Tachibana, Tomihisa; Ohshita, Yoshio; Prakash, Ronit R.; Sekiguchi, Takashi; Yamaguchi, Masafumi

    2016-02-01

    The details of the process of carrier recombination via the Shockley-Read-Hall (SRH) defect level, at the grain boundaries of multicrystalline silicon, were investigated. For this, the temperature-dependent recombination velocities, as determined by experiments, were analyzed by the application of an electron beam induced current method. For the model, the misorientation angles at the grain boundaries were defined using a multi-seed casting-growth method. The results of our experiments indicated different temperature behaviors at low and high temperatures. These can be explained by controlling the process anticipated by the SRH model, that is, the process whereby minority carriers (electrons) are captured at lower temperatures, followed by the reemission of the carriers before recombination with Arrhenius behavior at higher temperatures. The minority capture process appeared to conform to the power law T-α temperature behavior. Thus, there are two candidate electron capture mechanisms, namely, cascade phonon emission capture for shallow centers and excitonic-Auger capture for deep centers. The activation energy for the reemission of carriers was around 0.1 eV. These findings regarding the temperature dependence are essentially independent of the misorientation angles, suggesting a common defect level and recombination mechanism. The difference in the recombination velocities can be regarded as being derived from the difference in the density at the defect level.

  6. Radioactive wastes

    The standard deals with the management of radioactive wastes originating from radioactive isotopes and the operation of nuclear reactors and non-energetic nuclear power plants. It contains seven chapters: general aspects (the categories applied here were standardised in MSZ 62 and MSZ 14341/1), collection of radioactive wastes, temporary storage, tables of the quantities of dischargable isotopes, processing, transportation, and permanent storage of radioactive wastes. The standard became valid in Hungary on January 1, 1981. (Sz.J.)

  7. Total Artificial Heart

    ... the NHLBI on Twitter. What Is a Total Artificial Heart? A total artificial heart (TAH) is a ... outside power source. Normal Heart and CardioWest Total Artificial Heart Figure A shows the normal structure and ...

  8. Radioactive wastes

    The Standard determines the terms and categories of radioactive wastes originating from the application of radioactive isotopes and operation of nuclear reactors and non-energetic nuclear power plants. The terms of dosimetry, the classification of different radioactive sources (open an sealed sources, etc.), the danger classes of isotopes, the categorization of isotope laboratories (A-, B-, and C-level) are given. The waste categories, the minimal concentration and total activity values for qualifying any solid, liquid, biological or gaslike material as radioactive waste, a table for the most important isotopes, and another for unknown isotope compositions, the categories of liquid and gaslike radioactive wastes are also given. (Sz.J.)

  9. Probabilistic siting analysis of nuclear power plants emphasizing atmospheric dispersion of radioactive releases and radiation-induced health effects

    A presentation is made of probabilistic evaluation schemes for nuclear power plant siting. Effects on health attributable to ionizing radiation are reviewed, for the purpose of assessment of the numbers of the most important health effect cases in light-water reactor accidents. The atmospheric dispersion of radioactive releases from nuclear power plants is discussed, and there is presented an environmental consequence assessment model in which the radioactive releases and atmospheric dispersion of the releases are treated by the application of probabilistic methods. In the model, the environmental effects arising from exposure to radiation are expressed as cumulative probability distributions and expectation values. The probabilistic environmental consequence assessment model has been applied to nuclear power plant site evaluation, including risk-benefit and cost-benefit analyses, and the comparison of various alternative sites. (author)

  10. Artificial Sperm

    Nolte J

    2013-01-01

    Full Text Available Spermatogenesis is a complex mechanism that is controlled by an extensive network of hormonal activities within an outstanding organized and structured tissue. Spermatogonial stem cells (SSCs provide the basis of lifelong spermatogenesis by renewing the pool of SSCs balanced with differentiation into spermatogonia which will than give rise to spermatozoa. The process of spermatogenesis has been investigated by scientists all over the world for many decades. To understand the mechanisms leading to the development of haploid gametes originating from a stem cell, is at the same time fascinating and important since this is the process that leads to the next generation. To have a tool for the investigation of this outstanding process, the establishment of robust protocols for the in vitro generation and differentiation of spermatozoa is necessary. However, it is not only important for understanding the basics of spermatogenesis but also to create ex vivo systems for the generation of artificial sperm starting from immature germ cells from infertile patients.

  11. Artificial Economy

    Alexandru JIVAN

    2011-08-01

    Full Text Available This paper proposes to eliminate, a routine in the economic thinking, claimed to be responsible for the negative essence of economic developments, from the point of view, of the ecological implications (employment in the planetary ecosystem. The methodological foundations start from the natural origins of the functionality of the human economic society according to the originary physiocrat liberalism, and from specific natural characteristics of the humankind. This paper begins with a comment-analysis of the difference between natural and artificial within the economy, and then explains some of the most serious diversions from the natural essence of economic liberalism. It shall be explained the original (heterodox interpretation of the Classical political economy (economics, by making calls to the Romanian economic thinking from aggravating past century. Highlighting the destructive impact of the economy - which, under the invoked doctrines, we call unnatural - allows an intuitive presentation of a logical extension of Marshall's market price, based on previous research. Besides the doctrinal arguments presented, the economic realities inventoried along the way (major deficiencies and effects, determined demonstrate the validity of the hypothesis of the unnatural character and therefore necessarily to be corrected, of the concept and of the mechanisms of the current economy.The results of this paper consist of original heterodox methodspresented, intuitive or developed that can be found conclusively within the key proposals for education and regulation.

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

    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.)

  13. A case of propylthiouracil-induced antineutrophilic cytoplasmic antibody-positive vasculitis successfully treated with radioactive iodine

    C. Bes

    2013-07-01

    Full Text Available Antineutrophilic cytoplasmic antibody (ANCA associated vasculitis is one of the rare complications of propylthiouracil treatment. Having a variable clinical spectrum, it may be presented with both skin limited vasculitis and life-threatening systemic vasculitis. In this study, we present a case that developed ANCA-positive vasculitis with skin and kidney involvement (hematuria and proteinuria six months after propylthiouracil treatment was initiated for toxic nodular goiter. Proteinuria recovered dramatically subsequent to radioactive iodine treatment following ceasing the drug.

  14. Radioactivity. Centenary of radioactivity discovery; Radioactivite. Centenaire de la decouverte de la radioactivite

    Charpak, G. [Academie des Sciences, 75 - Paris (France); Tubiana, M. [Academie de Medecine, 75 - Paris (France); Bimbot, R. [Institut National de Physique Nucleaire et de Physique des Particules (India2P3), 75 - Paris (France)

    1997-12-31

    This small booklet was edited for the occasion of the exhibitions of the celebration of the centenary of radioactivity discovery which took place in various locations in France from 1996 to 1998. It recalls some basic knowledge concerning radioactivity and its applications: history of discovery, atoms and isotopes, radiations, measurement of ionizing radiations, natural and artificial radioactivity, isotope dating and labelling, radiotherapy, nuclear power and reactors, fission and fusion, nuclear wastes, dosimetry, effects and radioprotection. (J.S.)

  15. Gamma-H2AX as a biomarker of DNA damage induced by ionizing radiation in targeted and bystander human artificial skin models and peripheral blood lymphocytes

    Redon, Christophe; Dickey, Jennifer; Bonner, William; Sedelnikova, Olga

    Ionizing radiation (IR) exposure is inevitable. In addition to exposure from cosmic rays, the sun and radioactive substances, modern society has created new sources of radiation exposure such as space and high altitude journeys, X-ray diagnostics, radiological treatments and the increasing threat of radiobiological terrorism. For these reasons, a reliable, reproducible and sensitive assessment of dose and time exposure to IR is essential. We developed a minimally invasive diagnostic test for IR exposure based on detection of a phosphorylated variant of histone H2AX (gamma-H2AX), which occurs specifically at sites of DNA double-strand breaks (DSBs). The phosphorylation of thousands of H2AX molecules forms a gamma-H2AX focus in the chromatin flanking the DSB site that can be detected in situ. We analyzed gamma- H2AX focus formation in both directly irradiated cells as well as in un-irradiated "bystanders" in close contact with irradiated cells. In order to insure minimal invasiveness, we examined commercially available artificial skin models as a surrogate for human skin biopsies as well as peripheral blood lymphocytes. In human skin models, cells in a thin plane were microbeamirradiated and gamma-H2AX formation was measured both in irradiated and in distal bystander cells over time. In irradiated cells DSB formation reached a maximum at 15-30 minutes post- IR and then declined within several hours; all cells were affected. In marked contrast, the incidence of DSBs in bystander cells reached a maximum by 12-48 hours post-irradiation, gradually decreasing over the 7 day time course. At the maxima, 40-60% of bystander cells were affected. Similarly, we analyzed blood samples exposed to IR ex vivo at doses ranging from 0.02 to 3 Gy. The amount of DNA damage was linear in respect to radiation dose and independent of the age or sex of the blood donor. The method is highly reproducible and highly sensitive. In directly irradiated cells, the number of gamma-H2AX foci peaked 30 min after irradiation and then declined at a relatively steady pace as the cell repaired the DNA damage. Radiation effects were still detectable after 48 hrs for doses greater than 1 Gy and remained linear to initial dose. Activated bystander lymphocytes cultured with media from irradiated lymphocytes exhibited a two-fold increased damage response as seen by gamma- H2AX formation. The effect reached a maximum 3 hrs post-exposure and was retained for over 24 hrs. Thus, detection of gamma-H2AX formation to determine DNA damage in a minimally invasive skin test and a non-invasive blood test could be useful and promising tools to analyze direct and indirect effects of radiation exposure.

  16. Purification of highly-radioactive mouse interferon produced by Ehrlich ascites tumour cells induced by Sendai virus

    Mouse interferon (IFN) was produced to high titres after induction of Ehrlich ascites tumour cells with Sendai virus by using an improved procedure. The IFN molecules were labelled during their synthesis by the incorporation of [3H]leucine and [3H]lysine. Electrophoretically homogeneous labelled IFN with a molecular weight of 34000 was obtained after a two-step purification procedure using poly(I)-agarose and octyl-Sepharose column chromatography followed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The specific radioactivity of this IFN was about 10 ct/min/IFN unit. (author)

  17. Specific Radioactivity of Neutron Induced Radioisotopes: Assessment Methods and Application for Medically Useful 177Lu Production as a Case

    Van So Le

    2011-01-01

    Full Text Available The conventional reaction yield evaluation for radioisotope production is not sufficient to set up the optimal conditions for producing radionuclide products of the desired radiochemical quality. Alternatively, the specific radioactivity (SA assessment, dealing with the relationship between the affecting factors and the inherent properties of the target and impurities, offers a way to optimally perform the irradiation for production of the best quality radioisotopes for various applications, especially for targeting radiopharmaceutical preparation. Neutron-capture characteristics, target impurity, side nuclear reactions, target burn-up and post-irradiation processing/cooling time are the main parameters affecting the SA of the radioisotope product. These parameters have been incorporated into the format of mathematical equations for the reaction yield and SA assessment. As a method demonstration, the SA assessment of 177Lu produced based on two different reactions, 176Lu (n,?177Lu and 176Yb (n,? 177Yb (?- decay 177Lu, were performed. The irradiation time required for achieving a maximum yield and maximum SA value was evaluated for production based on the 176Lu (n,?177Lu reaction. The effect of several factors (such as elemental Lu and isotopic impurities on the 177Lu SA degradation was evaluated for production based on the 176Yb (n,? 177Yb (?- decay 177Lu reaction. The method of SA assessment of a mixture of several radioactive sources was developed for the radioisotope produced in a reactor from different targets.

  18. Japan Atomic Energy Research Institute/United States Integral Neutronics Experiments and Analyses for tritium breeding, nuclear heating, and induced radioactivity

    A large member of integral experiments for fusion blanket neutronics were performed using deuterium-tritium (D-T) neutrons at the Fusion Neutronics Source facility as part of a 10-yr collaborative program between the Japan Atomic Energy Research Institute and the United States. A number of measurement techniques were developed for tritium production, induced radioactivity, and nuclear heating. Transport calculations were performed using three-dimensional Monte Carlo and two-dimensional discrete ordinates codes and the latest nuclear data libraries in Japan and the United States. Significant differences among measurement techniques and calculation methods were found. To assure a 90% confidence level for tritium breeding calculations not to exceed measurements, designers should use a safety factor > 1.1 to 1.2, depending on the calculation method. Such a safety factor may not be affordable with most candidate blanket designs. Therefore, demonstration of tritium self-sufficiency is recommended as a high priority for testing in near-term fusion facilities such as the International Thermonuclear Experimental Reactor (ITER). The radioactivity measurements were performed for > 20 materials with the focus on gamma emitters with half-lives < 5 yr. Most discrepancies were attributed directly to deficiencies in the activation libraries, particularly errors in cross sections for certain reactions. 71 refs., 30 figs., 5 tabs

  19. Radioactivity; La radioactivite

    NONE

    1998-08-01

    This educative booklet give a general overview of radioactivity: history, structure of matter, radiations, radioactivity law, origin of radioactivity, radioactivity uses, radioprotection and measurement units. (J.S.)

  20. Study of the behaviour of artificial radioactive aerosols. Applications to some problems of atmospheric circulation (1963); Etude du comportement dcs aerosols radioactifs artificiels. Applications a quelques problemes de circulation atmospherique (1963)

    Lambert, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-11-15

    The aim of this work, consists in the examination of the behaviour of radioactive aerosols produced in the atmosphere by nuclear explosions, in order to deduce the most general laws governing atmospheric circulation and diffusion. After having given a general table of the radioactive aerosols present the authors consider the validity and the precision of the measurement methods and the concentration of the aerosols at ground level and in the upper atmosphere, as well as their deposition on the ground. The existence is thus demonstrated of a tropospheric equatorial barrier and of discontinuous and seasonal aspects of stratosphere-troposphere transfers. The role is shown of precipitations and dry auto-filtration in the lower atmosphere cleaning processes. This work makes it possible to describe the general behaviour of dust from the stratosphere, and to improve the total radioactive contamination of the globe. (author) [French] L'objectif de ce travail consiste a examiner le comportement des aerosols radioactifs introduits dans l'atmosphere par les explosions nucleaires, pour en deduire les lois les plus generals de la circulation et diffusion atmospheriques. Apres avoir dresse un tableau d'ensemble des aerosols radioactifs presents, on examine la validite et la precision des methodes de mesure de leur concentration, au niveau du sol et en haute atmosphere, ainsi que de leur depot a la surface du sol. On met ainsi en evidence l'existence d'une barriere equatoriale tropospherique; l'aspect discontinu et saisonnier des transferts stratosphere-troposphere; le role des precipitations et de l'auto-filtration seche, dans les processus de nettoyage de la basse atmosphere. Ces etudes permettent de decrire le comportement general des poussieres d'origine stratospherique et d'ameliorer le bilan de la contamination radioactive du globe. (auteur)

  1. A high-efficiency compact setup to study evaporation residues formed in reactions induced by low-intensity radioactive ion beams

    A setup for measuring cross-sections of evaporation residues produced in the collision of two heavy ions is described. The system, which detects all reaction products in a narrow angular range around the beam direction, is designed to work best with low-intensity beams (=5ions/s) and can be highly efficient for reactions studied in inverse kinematic conditions, i.e., heavy-mass beam on lighter-mass targets. The system as presented here has been optimized to study evaporation residues from reactions induced by radioactive ion beams with charges near Z?50 and energies near 4MeV/nucleon. Continuous sampling of the beam velocity, energy loss and position allow for the measurement of accurate evaporation residue cross-sections also in situations where the beam contains a mixture nuclides

  2. Reliability assessment of high energy particle induced radioactivity calculation code DCHAIN-SP 2001 by analysis of integral activation experiments with 14 MeV neutrons

    Kai, Tetsuya; Maekawa, Fujio; Kasugai, Yoshimi; Takada, Hiroshi; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kosako, Kazuaki [Sumitomo Atomic Energy Industries, Ltd., Tokyo (Japan)

    2002-03-01

    Reliability assessment for the high energy particle induced radioactivity calculation code DCHAIN-SP 2001 was carried out through analysis of integral activation experiments with 14-MeV neutrons aiming at validating the cross section and decay data revised from previous version. The following three kinds of experiments conducted at the D-T neutron source facility, FNS, in JAERI were employed: (1) the decay gamma-ray measurement experiment for fusion reactor materials, (2) the decay heat measurement experiment for 32 fusion reactor materials, and (3) the integral activation experiment on mercury. It was found that the calculations with DCHAIN-SP 2001 predicted the experimental data for (1) - (3) within several tens of percent. It was concluded that the cross section data below 20 MeV and the associated decay data as well as the calculation algorithm for solving the Beteman equation that was the master equation of DCHAIN-SP were adequate. (author)

  3. Radionuclides induced by environmental neutrons. Discovery of natural radioactive Eu and Co isotopes and their contribution to the evaluation of Atomic-bombing neutrons in Hiroshima and Nagasaki

    Radioactive europium and cobalt isotopes induced by environmental neutrons have been discovered by low-background Ge detector installed in Ogoya underground laboratory. Specific activities of 152Eu, 154Eu and 155Eu and 60Co were measured for recent and old europium and cobalt reagents. Observed activities are 0.06-0.52 dpm g-1 for 152Eu, 0.09-0.16 dpm g-1 for 154Eu and 0.005-0.16 dpm g-1 for 155Eu and 0.007-0.083 dpm g-1 for 60Co. Contribution of natural 152Eu and 60Co in Atomic-bomb exposed samples are found to be negligible low and less than 10%, respectively. (author)

  4. Reliability assessment of high energy particle induced radioactivity calculation code DCHAIN-SP 2001 by analysis of integral activation experiments with 14 MeV neutrons

    Reliability assessment for the high energy particle induced radioactivity calculation code DCHAIN-SP 2001 was carried out through analysis of integral activation experiments with 14-MeV neutrons aiming at validating the cross section and decay data revised from previous version. The following three kinds of experiments conducted at the D-T neutron source facility, FNS, in JAERI were employed: (1) the decay gamma-ray measurement experiment for fusion reactor materials, (2) the decay heat measurement experiment for 32 fusion reactor materials, and (3) the integral activation experiment on mercury. It was found that the calculations with DCHAIN-SP 2001 predicted the experimental data for (1) - (3) within several tens of percent. It was concluded that the cross section data below 20 MeV and the associated decay data as well as the calculation algorithm for solving the Beteman equation that was the master equation of DCHAIN-SP were adequate. (author)

  5. Environmental radioactivity and radiation exposure

    In 1977 population exposure in the Federal Republic of Germany has not changed as compared to the previous years. The main share of the total exposure, nearly two thirds, is attributed to natural radioactive substances and cosmic radiation. The largest part (around 85%) of the artificial radiation exposure is caused by X-ray diagnostics. In comparison to this, radiation exposure from application of ionizing radiation in medical therapy, use of radioactive material in research and technology, or from nuclear facilities is small. As in the years before, population exposure caused by nuclear power plants and other nuclear facilities is distinctly less than 1% of the natural radiation exposure. This is also true for the average radiation exposure within a radius of 3 km around nuclear facilities. On the whole, the report makes clear that the total amount of artificial population exposure will substantially decrease only if one succeeds in reducing the high contribution to the radiation exposure caused by medical measures. (orig.)

  6. Microscopic artificial swimmers

    Dreyfus, Rémi; Baudry, Jean; Roper, Marcus L.; Fermigier, Marc; Stone, Howard A.; Bibette, Jérôme

    2005-10-01

    Microorganisms such as bacteria and many eukaryotic cells propel themselves with hair-like structures known as flagella, which can exhibit a variety of structures and movement patterns. For example, bacterial flagella are helically shaped and driven at their bases by a reversible rotary engine, which rotates the attached flagellum to give a motion similar to that of a corkscrew. In contrast, eukaryotic cells use flagella that resemble elastic rods and exhibit a beating motion: internally generated stresses give rise to a series of bends that propagate towards the tip. In contrast to this variety of swimming strategies encountered in nature, a controlled swimming motion of artificial micrometre-sized structures has not yet been realized. Here we show that a linear chain of colloidal magnetic particles linked by DNA and attached to a red blood cell can act as a flexible artificial flagellum. The filament aligns with an external uniform magnetic field and is readily actuated by oscillating a transverse field. We find that the actuation induces a beating pattern that propels the structure, and that the external fields can be adjusted to control the velocity and the direction of motion.

  7. Measurement and simulation of induced radioactivity and remanent dose rates at the CERN-EU high energy reference field facility

    Full text: Various samples of materials typically used at high energy accelerators were irradiated by the stray radiation field produced by interactions of high energy hadrons in a copper target. Specific activities and remanent dose rates were measured at different cooling times and compared to results of detailed Monte-Carlo simulations using the FLUKA code. For the calculation of remanent dose rates, a new approach has been developed and applied to the experimental setup. It is based on an explicit calculation of isotope production followed by a complete transport of the photons, electrons, and positrons from the radioactive decays to the point of interest. Finally, examples are given for applications of this method to the estimation of remanent dose rates at the large hadron collider, especially the two beam cleaning insertions. (author)

  8. Experimental investigation of radioactivity induced in the fusion power plant structural material SiC and in the breeder material Li4SiO4 by 14-MeV neutrons

    The radioactivity induced by neutrons in the materials of fusion power plants is a focus of investigations dedicated to safety and environmental assessments of fusion power. The greatest part of the radioactivity is produced by two components of the neutron flux spectrum, by thermal neutrons and by the 14-MeV DT fusion neutrons. The low-activation material SiC and the tritium-generating material Li4SiO4 were irradiated with 14-MeV neutrons, and the γ-activity induced was measured several times during the decay. The results were analysed with the European Activation System EASY-99 with respect to short-term and long-term radioactivity

  9. The environmental assessment of radioactive materials using yeast DNA microarray. Genomic profiling of thorium-induced changes in yeast cells

    We evaluated the toxicity of thorium (nitrate) in the environment by using a Saccharomyces cerevisiae DNA microarray, and present the genome-wide profile of induced yeast genes. A total of 185 out of about 6,000 genes spotted on the microarray chip were induced by thorium. Functional analysis of these genes revealed that gene categories in 'C-compound and carbohydrate metabolism', 'Energy', 'Lipid fatty acid and isoprenoid metabolism' and 'Cell rescue, defense and virulence' were the most highly induced by thorium treatment. Moreover, localization analysis of these genes revealed that gene categories in 'Extracellular', 'Cell wall', 'Plasma membrane' and 'Cell periphery' were also highly induced by thorium treatment. In the categories of 'Cell rescue, defense and virulence', genes related to oxidative stress were induced. In the categories of 'C-compound and carbohydrate metabolism' and 'Energy', genes relate to glycogen metabolism were observed. In the categories of 'Extracellular' and 'Cell wall', genes related to cell component were detected while genes related to sugar transporters were detected in the categories of Plasma membrane'. These results provide the first insight into the effect of thorium on yeast cells. (author)

  10. Application of a series of artificial neural networks to on-site quantitative analysis of lead into real soil samples by laser induced breakdown spectroscopy

    Artificial neural networks were applied to process data from on-site LIBS analysis of soil samples. A first artificial neural network allowed retrieving the relative amounts of silicate, calcareous and ores matrices into soils. As a consequence, each soil sample was correctly located inside the ternary diagram characterized by these three matrices, as verified by ICP-AES. Then a series of artificial neural networks were applied to quantify lead into soil samples. More precisely, two models were designed for classification purpose according to both the type of matrix and the range of lead concentrations. Then, three quantitative models were locally applied to three data subsets. This complete approach allowed reaching a relative error of prediction close to 20%, considered as satisfying in the case of on-site analysis. - Highlights: • Application of a series of artificial neural networks (ANN) to quantitative LIBS • Matrix-based classification of the soil samples by ANN • Concentration-based classification of the soil samples by ANN • Series of quantitative ANN models dedicated to the analysis of data subsets • Relative error of prediction lower than 20% for LIBS analysis of soil samples

  11. Application of a series of artificial neural networks to on-site quantitative analysis of lead into real soil samples by laser induced breakdown spectroscopy

    El Haddad, J. [Univ. Bordeaux, LOMA, CNRS UMR 5798, F-33400 Talence (France); Bruyère, D. [BRGM, Service Métrologie, Monitoring et Analyse, 3 av. C. Guillemin, B.P 36009, 45060 Orléans Cedex (France); Ismaël, A.; Gallou, G. [IVEA Solution, Centre Scientifique d' Orsay, Bât 503, 91400 Orsay (France); Laperche, V.; Michel, K. [BRGM, Service Métrologie, Monitoring et Analyse, 3 av. C. Guillemin, B.P 36009, 45060 Orléans Cedex (France); Canioni, L. [Univ. Bordeaux, LOMA, CNRS UMR 5798, F-33400 Talence (France); Bousquet, B., E-mail: bruno.bousquet@u-bordeaux.fr [Univ. Bordeaux, LOMA, CNRS UMR 5798, F-33400 Talence (France)

    2014-07-01

    Artificial neural networks were applied to process data from on-site LIBS analysis of soil samples. A first artificial neural network allowed retrieving the relative amounts of silicate, calcareous and ores matrices into soils. As a consequence, each soil sample was correctly located inside the ternary diagram characterized by these three matrices, as verified by ICP-AES. Then a series of artificial neural networks were applied to quantify lead into soil samples. More precisely, two models were designed for classification purpose according to both the type of matrix and the range of lead concentrations. Then, three quantitative models were locally applied to three data subsets. This complete approach allowed reaching a relative error of prediction close to 20%, considered as satisfying in the case of on-site analysis. - Highlights: • Application of a series of artificial neural networks (ANN) to quantitative LIBS • Matrix-based classification of the soil samples by ANN • Concentration-based classification of the soil samples by ANN • Series of quantitative ANN models dedicated to the analysis of data subsets • Relative error of prediction lower than 20% for LIBS analysis of soil samples.

  12. Radioactive Wastes.

    Choudri, B S; Baawain, Mahad

    2015-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2014. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes. PMID:26420096

  13. Reduction of radioactivity produced by nuclear explosives

    Four main sources contribute to the radioactivity produced by a nuclear explosive: 1. Fission products from the nuclear explosive, 2. Fusion products from the nuclear explosive, 3. Induced radioactivity in the nuclear explosive, 4. Induced radioactivity in the environment. This paper will summarize some of the work done at the Lawrence Radiation Laboratory at Livermore to reduce the radioactivity from these sources to levels acceptable for peaceful applications. Although it is theoretically possible to have no radioactivity produced by nuclear explosives, this goal has not been achieved

  14. Radioactive implant induced x-ray emission technique for noninvasive determination of iodine content in thyroid: experimental study

    A new technique, radioactive implant x-ray emission spectrometry to determine the in vivo iodine content of the human thyroid is proposed. The variations of counting rate and effective excitation efficiencies of I Ksub(α) (28.6 keV) with iodine content, thyroid volume and skin-thyroid distance were studied for the 201Tl source to examine the properties of excitation and photon attenuation. As a result, the gland depth and volume could be estimated from the peak ratios of 30.7 keV/167.6 keV and 28.6 keV/167.6 keV. Using a 1 MBq 201Tl implant source, the detectable minimum iodine concentration found was approximately 70 μg/g for 2000 s measuring time in the phantom experiment. The effectiveness of the RIXE technique is discussed. It was concluded that the 201Tl RIXE spectrometry might serve to determine the in vivo iodine content of the human thyroid. (author)

  15. Subject: Radioactivity

    Having dealt with the history of uranium mining and reactor catastrophe as the worst of feasible nuclear accidents the author proceeds to discuss the risks from radioactivity. The fact that contact with sources of radioactivity has become an everyday problem has led to a general awareness of the health consequences and presence of radioactivity as a decisive cofactor. The report challenges the trust-worthiness of experts and discusses the possibilities for citizens to offer resistance. Radiation-related diseases cannot be cured without taking political action and here the focus of attention must be shifted from individual cases and the limited availability of medical treatment to long-term preventive measures to be taken on a population-wide basis. This appears indispensable in view of the risks posed by radioactivity. (BBR)

  16. Determination of pharmacokinetic processes in body organs on the basis of the box model and, by analogy, of laws of radioactive disintegration of naturally occurring and artificially activated isotope families

    The research work described is based on the simple law of degradation and disintegration for pharmaceutical substances. The transport, storage and, possibly, accumulation of beneficial and harmful pharmaceuticals in the organs of the human body are analysed using the box model. The studies are not restricted to asymptotic conditions occurring after continuous treatment with a particular drug but also investigate into the so-called stabilisation phase immediately after the beginning of medication, which is described mathematically. This phase is shown to be subject to a set of rules that are much more complex than those responsible for asymptotic substance levels. The analytical procedures used here are described on the basis of typical cases drawn from medical practice. The laws derived from these observations can, by analogy, also be applied to the radioactive disintegration of isotope families. They also permit formulas to be determined for the activity of multiple-link chain members. The report proceeds by discussing cases, where the baseline substance is the result of nuclear chain reacting. The last issue to be treated within the scope of this study is the radioactive disintegration and simultaneous activation of isotope families. (orig./MG)

  17. Transformation and clustering of defects induced by electron irradiation in barium hollandite ceramics for radioactive cesium storage: Electron paramagnetic resonance study

    Aubin-Chevaldonnet, V.; Gourier, D.; Caurant, D.; Costantini, J.-M.

    2012-04-01

    Barium hollandite-type ceramics have been envisaged for the immobilization of radioactive cesium. To evaluate their stability under irradiation, a hollandite ceramic of composition Ba1.16Al2.32Ti5.68O16 was irradiated with electrons at a temperature close to room temperature to simulate the effect of ?- and ?-decays of cesium. Ti3+ and O2- paramagnetic defects induced by electron irradiation [V. Aubin-Chevaldonnet et al., J. Phys.: Condens. Matter 18, 4007 (2006)] were detected by electron paramagnetic resonance. As the temperature in the bulk of the hollandite waste form could reach 300 C at the beginning of the storage, the thermal stability of these paramagnetic defects was also studied. Isothermal annealing treatments at 300 C and isochronal annealing treatments between 50 C and 800 C show that the irradiation induced Ti3+ (E1 and E2 centers) and O2- (H centers) do not recombine. Instead, they partially transform during annealing, respectively, into titanyl TiO+ centers (E3 centers) at the grain surface and into paramagnetic clusters of O2- of less than 10 nm size (G2 centers), trapped in the bulk of the grains. These oxygen-rich aggregates could prefigure the formation of molecular oxygen observed in electron irradiated glasses.

  18. Walter Russell's concepts as the basis for an alternative view on radioactivity induced oxygen-ozone depletion and food chain pollution; and as the basis for alternative fuels, materials, energy production, and radioactive waste cleanup

    The following topics with supporting data will be presented: The transmutation of atmospheric nitrogen into carbon 14 and tritium via radioactivity as a source of omnipresent food and water pollution, and the possible correlation of oxygen transmutation into carbon 14 and tritium by the same mechanisms as well as into sulfur. Walter Russell's four pole field dual polarity control as a basis for transmutation will be discussed with reference to past and contemporary results of experimentation on this basis. Extension of the concepts into free hydrogen energy fuel, nitrogen fertilizers, other materials production,and transmutation of radioactive wastes into non radioactive elements will be discussed

  19. The radioactivity of the sea

    Walker, M.I.; Rose, K.S.B. (AEA Enviroment and Energy, Harwell (UK). Environmental Safety Div.)

    1990-08-01

    The radioactivity in the world's surface sea water averages 13.6 Bq/kg of water. Over 88% of this activity arises from a single natural radionuclide, {sup 40}K, and 7% of the remainder results from nuclear weapon test fallout. Variations in the radioactivity occur due to changes in salinity, weapon test fallout and discharges of artificial radionuclides, and are examined here on the basis of published measurements. The most radioactive sea identified by these measurements is the Dead Sea, which averages 178 Bq/kg due to its high salinity. Other enclosed, highly saline waters can be expected to have similar levels. The radioactivity in open seas varies within a much narrower range, generally within 20% of the world average. The highest averages are found in the Persian Gulf (22 Bq/kg), the Red Sea (15 Bq/kg) and the Eastern Mediterranean (14.6 Bq/kg). The Irish Sea averaged 13.7 Bq/kg in 1987, with the effect of the Sellafield discharges being partly offset by lower than average salinity. Although higher levels occurred in the Irish Sea during the 1970s when the Sellafield discharges were higher, the average level has always been much less than that in the Dead Sea, so that the Irish Sea has never been the most radioactive sea in the world. Exceptionally low levels of radioactivity (4 Bq/kg) occur in the Baltic Sea due to dilution by fresh water. (author).

  20. The radioactivity of the sea

    The radioactivity in the world's surface sea water averages 13.6 Bq/kg of water. Over 88% of this activity arises from a single natural radionuclide, 40K, and 7% of the remainder results from nuclear weapon test fallout. Variations in the radioactivity occur due to changes in salinity, weapon test fallout and discharges of artificial radionuclides, and are examined here on the basis of published measurements. The most radioactive sea identified by these measurements is the Dead Sea, which averages 178 Bq/kg due to its high salinity. Other enclosed, highly saline waters can be expected to have similar levels. The radioactivity in open seas varies within a much narrower range, generally within 20% of the world average. The highest averages are found in the Persian Gulf (22 Bq/kg), the Red Sea (15 Bq/kg) and the Eastern Mediterranean (14.6 Bq/kg). The Irish Sea averaged 13.7 Bq/kg in 1987, with the effect of the Sellafield discharges being partly offset by lower than average salinity. Although higher levels occurred in the Irish Sea during the 1970s when the Sellafield discharges were higher, the average level has always been much less than that in the Dead Sea, so that the Irish Sea has never been the most radioactive sea in the world. Exceptionally low levels of radioactivity (4 Bq/kg) occur in the Baltic Sea due to dilution by fresh water. (author)

  1. Artificial Radiotracer Applications in Aquatic Environments

    The use of artificial radiotracers in the environment is analogous to their use in the human body. In both domains they provide data on flow rates and pathways, on exchange with materials and on their final discharge from the studied system. Artificially injected radiotracers have been used to investigate flow in natural waters since the 1950's. Identification of flow paths, diagnosis of blockages or leakage, measurement of flow rates, dispersion and exchange processes, such as biological uptake or sorption, are all aspects to which a wide range of artificial radioactive tracers have been applied. Increasingly radiotracers are used in combination with numerical modelling to improve confidence in the predictive capacity of models used in the management of our water resources and to extend their spatial applicability. In turn this allows us to use less and less tracer and demonstrate that the human and environmental impact of modern radiotracer studies is minimal. (author)

  2. Ambient radioactivity levels and radiation doses. Annual report 2013; Umweltradioaktivitaet und Strahlenbelastung. Jahresbreicht 2013

    Hachenberger, Claudia; Trugenberger-Schnabel, Angela; Loebke-Reinl, Angelika; Peter, Josef (comps.) [Bundesamt fuer Strahlenschutz, Salzgitter (Germany)

    2015-04-15

    The report on environmental radioactivity and radiation exposure 2013 includes data concerning the following issues: sources of natural and artificial radioactivity, radon in buildings, radioactive materials in construction materials and industrial products, nuclear weapon tests, the consequences of reactor accidents in Chernobyl and Fukushima, nuclear facilities, occupational exposure, radiation exposure from medical applications, handling of radioactive materials in research and technology, radioactive wastes, radiation accidents and specific incidents.

  3. Measurement of radioactivity in steel

    Even after the control of scrap deliveries, there remains a small risk that the radioactive contaminated scrap passes the detecting devices. Therefore, the chemical laboratory takes a role to measure each heat for the absence of artificial radioactive nuclides with a gamma spectrometer equipped with NaI-detector. As the measurement must be performed in sequence with the steel production process, the allowable time for the measurement is quite limited. On the other hand, there could be still some possibility that background radiation might be present as the samples may contain some natural radioactivity. The task is how to differentiate the nature of radioactivity between naturally remaining radioactivity within safe limit and artificial nuclides present in the sample at a low level even though a very small amount of radioactivity could be detected in short time in both cases. We have set the alarm limit to 0.1 Bq/g for Co-60 as indicating nuclide. This limit is set more than 4 s (s = standard deviation) from the average background radiation. Therefore, false alarms are quite improbable. Strategy: The NaI gamma spectrometer performs a gross gamma measurement but it can not differentiate the nature of the nuclides present. If the alarm limit is hurt, the sample is measured on a high resolution gamma spectrometer with Ge-detector for identification of the gamma emitting nuclides. Calibration: Even though no appropriate international standards are adapted and no commercial measuring equipment is commercially available, the desired standard should contain Co-60 in the order of 1 to 100 Bq/g. The presence of other gamma emitting nuclides is desirable. In the Workshop we will present how to surmount this difficulty. (author)

  4. Risk analysis of radioactive waste disposal in salt deposits

    The use of salt mines and artificial holes in salt deposits for definitive storage of radioactive wastes is discussed. A risk analysis is made with special attention to geological effects and long term radionuclide migration. Other natural causes of a come back of radioactive nuclides in the biosphere could be neglected. The risks as a consequence of human actions have been neglected

  5. FY1995 new technology of artificial organ materials which can induce host biocompatibility; 1995 nendo jinko zokiyo seitai kino fukatsukagata sozai no kaihatsu gijutsu

    NONE

    1996-05-01

    The aim of this project is to produce a highly biocompatible materials for next generation's artificial organs using the following methods: 1, Micromodification of polymer materials. 2, Biocompatible treatment for biological materials. 3, Application of bioabsorbable materials. 4, Bioactive substance immobilization. and 5, Use of autologous tissue as artificial organ materials. As a synthetic polymer material, microporous polyurethane was used for a small diameter vascular prosthesis. The graft with this technology was successfully implanted in rat abdomical aortic position. The graft of 1.5 mm in internal diameter and 10 cm in length showed excellent patency with nice endothelialisation. As a biological material, microfibers of collagen was used for a sealing substance of vascular prothesis. The microfibers absorbed a large amount of water, which could prevent blood leakage from the graft wall. The graft showed non-thrombogenic property and excellent host cell affinity, resulted in rapid neointima formation. As to autologous tissue, bone marrow was used, since marrow cells can differentiate into any mesenchimal cells with synthesis of growth factors. Marrow cell transplanted vascular prothesis showed rapid capillary ingrowth. These results indicated that the newly designed materials had suitable properties for materials of next generation's artificial organs. (NEDO)

  6. FY1995 new technology of artificial organ materials which can induce host biocompatibility; 1995 nendo jinko zokiyo seitai kino fukatsukagata sozai no kaihatsu gijutsu

    NONE

    1996-12-01

    The aim of this project is to produce a highly biocompatible materials for next generation's artificial organs using the following methods: 1, Micromodification of polymer materials. 2, Biocompatible treatment for biological materials. 3, Application of bioabsorbable materials. 4, Bioactive substance immobilization. and 5, Use of autologous tissue as artificial organ materials. As a synthetic polymer material, microporous polyurethane was used for a small diameter vascular prosthesis. The graft with this technology was successfully implanted in rat abdomical aortic position. The graft of 1.5 mm in internal diameter and 10cm in length showed excellent patency with nice endothelialisation. As a biological material, microfibers of collagen was used for a sealing substance of vascular prothesis. The microfibers absorbed a large amount of water, which could prevent blood leakage from the graft wall. The graft showed non-thrombogenic property and excellent host cell affinity, resulted in rapid neointima formation. As to autologous tissue, bone marrow was used, since marrow cells can differentiate into any mesenchimal cells with synthesis of growth factors. Marrow cell transplanted vascular prothesis showed rapid capillary ingrowth. These results indicated that the newly designed materials had suitable properties for materials of next generation's artificial organs. (NEDO)

  7. The puzzle of nuclear wastes. Radioactive threat to your health..

    This document, published by the French association 'Sortir du nucleaire' (Get out of nuclear), gives some information on what is radioactivity, the radioactive materials as a risk for living organisms, nuclear wastes all over France (list and map of the storage sites, power plants and fuel cycle centers), nuclear wastes at every step of the nuclear connection, the insolvable problem of high activity wastes, burying nuclear wastes in order to better forget them, radioactivity as a time bomb for our health, radioactive effluents as an under-estimated risk, artificial radioactivity already responsible for the death of 61 million people in the world, and so on

  8. Determination of the fission barrier height in fission of heavy radioactive beams induced by the (d,p)-transfer

    A theoretical framework is described, allowing to determine the fission barrier height using the observed cross sections of fission induced by the (d,p)-transfer with accuracy, which is not achievable in another type of low-energy fission of neutron-deficient nuclei, the $\\beta$-delayed fission. The proposed experiment [1] at the HIE-ISOLDE, using the ACTAR TPC, will thus provide the experimental information, which is not available at the moment and which is highly interesting for nuclear theory.

  9. Molecular recognition and organizational and polyvalent effects in vesicles induce the formation of artificial multicompartment cells as model systems of eukaryotes.

    Paleos, Constantinos M; Pantos, A

    2014-05-20

    Researchers have become increasingly interested in the preparation and characterization of artificial cells based on amphiphilic molecules. In particular, artificial cells with multiple compartments are primitive mimics of the structure of eukaryotic cells. Endosymbiotic theory, widely accepted among biologists, states that eukaryotic cells arose from the assembly of prokaryotic cells inside other cells. Therefore, replicating this process in a synthetic system could allow researchers to model molecular and supramolecular processes that occur in living cells, shed light on mass and energy transport through cell membranes, and provide a unique, isolated space for conducting chemical reactions. In addition, such structures can serve as drug delivery systems that encapsulate both bioactive and nonbiocompatible compounds. In this Account, we present various coating, incubation, and electrofusion strategies for forming multicompartment vesicle systems, and we are focusing on strategies that rely on involving molecular recognition of complementary vesicles. All these methods afforded multicompartment systems with similar structures, and these nanoparticles have potential applications as drug delivery systems or nanoreactors for conducting diverse reactions. The complementarity of interacting vesicles allows these artificial cells to form, and the organization and polyvalency of these interacting vesicles further promote their formation. The incorporation of cholesterol in the bilayer membrane and the introduction of PEG chains at the surface of the interacting vesicles also support the structure of these multicompartment systems. PEG chains appear to destabilize the bilayers, which facilitates the fusion and transport of the small vesicles to the larger ones. Potential applications of these well-structured and reproducibly produced multicompartment systems include drug delivery, where researchers could load a cocktail of drugs within the encapsulated vesicles, a process that could enhance the bioavailability of these substances. In addition, the production of artificial cells with multiple compartments provides a platform where researchers could carry out individual reactions in small, isolated spaces. Such a reactive space can avoid problems that occur when the environment can be destructive to reactants or products or when a diverse set of compounds difficult to obtain in a conventional reactor space are produced. Our work on these artificial cells with multicompartment structures also led us to formulate a hypothesis on the processes that possibly generated eukaryotic cells. We hope both that our research efforts will excite interest in these nanoparticles and that this research could lead to systems designed for specific scientific and technological applications and further insights into the evolution of eukaryotic cells. PMID:24735049

  10. From Polonium to Artificial Radioisotopes in the 1930's

    The word '' radioactive '' appeared for the first time in Pierre and Marie Curie's paper announcing the discovery of Polonium. Starting with the memory of this seminal event and the discovery of Radium, we focus on a few of the tremendous successes achieved in the 30's, namely the successive discoveries of the neutron and the positive electron, followed by the discoveries of artificial radioactivity and later of fission. Experimentalists were confronted with many problems as their interest shifted from radioactivity to '' artificial disintegration '' and cosmic rays experiments. The first discovered ?+ radioactive isotopes, 30P and 13N, and the first fission produced nuclei appear as early steps towards the quest for more and more exotic nuclei. (author)

  11. Environmental radioactivity surveillance programme 1990 - 1993

    During the period 1990-1993, the Radiological Protection Institute of Ireland continued its programme of measuring radioactivity levels in airborne dust, rainwater, total fallout, drinking water supplies and milk. The levels of artificially produced radionuclides continue to be insignificant from a radiological safety point of view

  12. History of radioactivity

    The author describes the historical development of the physics of atoms and nuclei. After a consideration of the ancient Greek philosophy concerning atoms the behaviour of gases is discussed with regards to statistical mechanics. Then the developement of chemistry from alchemy is described. Thereafter the early studies of gas discharges are described with regards to the electronic structure of atoms. In this connection the periodic system of elements is considered. Then the detection of the α-radiation of Uranium by Becquerel and the detections of M. and P. Curie are described. Thereafter the radiactive decay of nuclei is discussed. Then a popular introduction into nuclear structure is given with special regards to artificial radioactivity and nuclear fission. Finally nuclear reactors, the atomic bombs, applications of radionuclides, and problems of radiation protection are described. (HSI)

  13. Wear measurement using radioactive tracer technique based on proton, deuteron and α-particle induced nuclear reactions on molybdenum

    Highlights: ► Proton, deuteron, 3He and α-particle activation of Mo. ► TLA (thin layer activation). ► Wear measurement. ► Integral production yields. ► Wear curves (specific activity versus penetration depth). - Abstract: Excitation functions of light ion induced nuclear reactions on natural molybdenum have been studied in the frame of a systematic investigation of charged particle induced nuclear reactions on metals for various applications. Excitation functions of 93,94g,94m,95g,95m,96,99mTc, 90,93m,99Mo, 90,91m,92m,95m,95g,96Nb and 88,89Zr were measured up to 50 MeV deuteron energy Tárkányi et al., 2012 [1], 93m,93g,94m,94g,95m,95g,96g,99mTc, 90,93m,99Mo, 90,92m,95m,95g,96Nb and 88,89Zr were measured up to 40 MeV proton energy Tárkányi et al., 2012 [2] and 93m,93g,94m,94g,95m,95g,96g,99mTc, 93m,99Mo, 90Nb, 94,95,97,103Ru and 88Zr were measured up to 40 MeV alpha energy Ditrói et al., 2012 [3] by using the stacked foil technique and activation method. The results for 3He induced reactions on natural Mo were taken from the literature Comparetto and Qaim, 1980 [4]. According to their half-lives, from the above listed radionuclides the 95m,96Tc, 91m,92m,95m,95gNb, 99Mo, 103,97Ru and 88Zr are suitable candidates for wear measurement by using thin layer activation (TLA) method. The goal of this work was to determine the necessary nuclear data for TLA of the above radionuclides and to prove their applicability for wear measurements.

  14. Radioactivity and the French uranium bearing minerals

    This special issue of Regne Mineral journal is entirely devoted to the French uranium mining industry. It comprises 4 parts dealing with: the uranium mining industry in France (history, uranium rush, deposits, geologic setting, prosperity and recession, situation in 1998, ore processing); radioactivity and the uranium and its descendants (discovery, first French uranium bearing ores, discovery of radioactivity, radium and other uranium descendants, radium mines, uranium mines, atoms, elements and isotopes, uranium genesis, uranium decay, isotopes in an uranium ore, spontaneous fission, selective migration of radionuclides, radon in mines and houses, radioactivity units, radioprotection standards, new standards and controversies, natural and artificial radioactivity, hazards linked with the handling and collecting of uranium ores, conformability with radioprotection standards, radioactivity of natural uranium minerals); the French uranium bearing minerals (composition, crystal structure, reference, etymology, fluorescence). (J.S.)

  15. Radioactive waste

    In the authors' view, plutonium production, as well as soil dumping of radioactive waste, should halt immediately: the public dangers are simply too high. DOE's de facto outlaw status in complying with environmental laws must also change. EPA should be able to enforce the same standards for DOE as for the private sector. And the only way to ensure that DOE effectively cleans up its wastes is to set up a long-term spending mechanism such as Superfund. Regardless of how these issues are resolved, the radioactive and hazardous material that is the legacy of the nuclear arms race will affect surrounding communities for centuries

  16. Experimental verification of the current data and methods for induced radioactivity and decay heat calculation in D-T fusion reactors

    Induced radioactivities and decay heat are of significant importance in the nuclear design of a near-term D-T fusion device from the view point of the safety consideration. In the framework of the JAERI/USDOE collaborative program on fusion neutronics, extensive experimental efforts have been devoted to verify the validity of the calculation code systems THIDA-2, REACT-2 and DKR-ICF. In the previous study, it was clearly pointed out that there were large discrepancies for several important materials between the experiment and the calculation in terms of y-ray emission rates. This paper investigated the major sources of these large discrepancies. In addition to the previous ones, the analysis was carried out by THIDA-2 using an updated cross-section library. As a result, the following was pointed out: (1) The calculation of THIDA with the new activation cross-section library gave better agreement with experiment, especially for MnCu, W, Mo and V. As far as the higher neutron energy range above 1.0 MeV is concerned, all calculation code systems offer reasonable prediction accuracy. (2) For MnCu, W and Ta, uncertainty in the neutron spectrum was the main source for the large discrepancies because low-energy neutrons were very sensitive to the capture reaction products of 64Cu, 187W and 182Ta. (orig.)

  17. Radioactivity monitoring in Ireland of air, deposition and water 1982-1987

    The Nuclear Energy Board in conjunction with the Meteorological Service undertakes an environmental radioactivity monitoring programme with the objective of determining levels of artificially produced radioactivity in the Irish environment. The levels of radioactivity in airbourne dust, total fallout samples, precipitation and drinking water are presented for 1982, 1983, 1984, 1985, 1986 and 1987

  18. Radioactivity Monitoring of the Irish Environment 2006

    This report presents the results of the environmental radioactivity monitoring programme carried out by the Radiological Protection Institute of Ireland (RPII) in 2006. This programme aims to assess the exposure of the Irish population to artificial radioactivity in the environment, to review the temporal and geographical distribution of contaminating radionuclides and to maintain systems and procedures which would allow a rapid assessment of environmental contamination to be made in the event of a radiological emergency. Radioactivity is present in the environment due to natural processes, the testing of nuclear weapons in the atmosphere, past nuclear accidents such as that at Chernobyl in Ukraine and the routine discharge of radionuclides from nuclear installations. Liquid discharges from the British Nuclear Group reprocessing plant at Sellafield in Cumbria in the north-west of England, which are licensed by the UK Environment Agency, continue to be the dominant source of artificial radioactivity in the Irish marine environment. The key elements of the monitoring programme implemented by the RPII in 2006 included; assessment of ambient radioactivity based on measurements of radioactivity in air and of external gamma dose rate at permanent monitoring stations located throughout the country; assessment of levels of radioactivity in drinking water; assessment of levels of radioactivity in foodstuffs based on measurements of total diet, milk and various ingredients; assessment of levels of radioactivity in the Irish marine environment based on sampling and measurement of seawater, sediment, seaweed, fish and shellfish. The RPII monitored airborne radioactivity at ten stations located throughout the country. One of these stations is equipped with a high volume sampler, which allows concentrations of caesium-137 to be measured; another is equipped to detect the presence of the gas krypton-85. This gas is released into the environment primarily as a result of the reprocessing of nuclear fuel. During 2006, levels of radionuclides in airborne radioactivity were low and consistent with measurements in previous years. External gamma dose rates were monitored continuously at fifteen stations. No abnormal levels were observed. In accordance with the RPII's drinking water monitoring protocol, a number of water supplies from Cork, Dublin, Galway and Limerick were tested and found to be within the requirements for radioactivity set out in the relevant national standards. The RPII sampled and measured levels of radioactivity in mixed diet, milk and various other foodstuffs including milk products, baby foods, beef, lamb, poultry and vegetables. These measurements show that levels of artificial radioactivity in the Irish diet continue to be low. In the region of 170 samples of fish, shellfish, seaweed, seawater and sediment were analysed for a range of radionuclides. Along the Irish coastline the highest radioactivity concentrations observed were in the north-east. The main pathway contributing to the exposure of the Irish public to artificial radioactivity from the marine environment is the consumption of seafood. Caesium-137 continues to be the dominant radionuclide, accounting for approximately 70% of the total dose. The dose to the Irish population due to caesium-137 has declined significantly over the last two decades corresponding to the reduction in discharges of this radionuclide from Sellafield. The annual doses incurred by the Irish public as a result of artificial radioactivity in the environment do not constitute a significant health risk and are small compared with the dose received as a result of natural radiation

  19. Artificial ferroelectricity in perovskite superlattices

    Artificial superlattices of SrZrO3(SZO)/SrTiO3(STO) were fabricated by molecular-beam epitaxy. Lattice parameters showed that the lattice distortion (c/a ratio) attained a maximum value in the [(SZO)10/(STO)10]4 superlattice. Dielectric relaxation was observed in the [(SZO)1/(STO)1]40 and [(SZO)10/(STO)10]4 superlattices in the low frequency domain. Dielectric permittivity of the SZO/STO superlattices was over 10 000 at 110 MHz. The SZO/STO superlattices showed clear Q-V hysteresis curves, which indicated that ferroelectricity was induced artificially in the superlattices in spite of the paraelectric nature of SZO and STO. The origin of the ferroelectricity was related to the anisotropic lattice distortion in the superlattice structure

  20. High energy muon induced radioactive nuclides in nickel plate and its use for 2-D muon-beam image profile

    Kurebayashi, Y.; Sakurai, H.; Takahashi, Y.; Doshita, N.; Kikuchi, S.; Tokanai, F.; Horiuchi, K.; Tajima, Y.; Oe, T.; Sato, T.; Gunji, S.; Inui, E.; Kondo, K.; Iwata, N.; Sasaki, N.; Matsuzaki, H.; Kunieda, S.

    2015-11-01

    Target materials were exposed to a muon beam with an energy of 160 GeV/c at the COMPASS experiment line in CERN-SPS to measure the production cross-sections for muon-induced radionuclides. A muon imager containing four nickel plates, each measuring 100 mm100 mm, exposed to the IP plate successfully detected the muon beam image during an irradiation period of 33 days. The contrasting density rate of the nickel plate was (5.20.7)10-9 PSL/muon per one-day exposure to IP. The image measured 122 mm and 174 mm in horizontal and vertical lengths, respectively, in relation to the surface of the base, indicating that 506% of the muon beam flux is confined to an area of 18% of the whole muon beam. The number of muons estimated from the PSL value in the total beam image area (0.810.1)1013 was comparable to the total muon counts of the ion-chamber at the M2 beam line in the CERN-SPS. The production cross-sections of Cr-51, Mn-54, Co-56, Co-57, and Co-58 in nickel were 0.190.08, 0.340.06, 0.50.05, 3.440.07, 0.40.03 in the unit of mb, respectively, reducing muon associated particles effects. They are approximately 10 times smaller than that a proceeding study by Heisinger et al.

  1. Quo Vadis, Artificial Intelligence?

    Alfons Schuster; Daniel Berrar; Naoyuki Sato

    2010-01-01

    Since its conception in the mid 1950s, artificial intelligence with its great ambition to understand and emulate intelligence in natural and artificial environments alike is now a truly multidisciplinary field that reaches out and is inspired by a great diversity of other fields. Rapid advances in research and technology in various fields have created environments into which artificial intelligence could embed itself naturally and comfortably. Neuroscience with its desire to understand nervou...

  2. Artificial cognition architectures

    Crowder, James A; Friess, Shelli A

    2013-01-01

    The goal of this book is to establish the foundation, principles, theory, and concepts that are the backbone of real, autonomous Artificial Intelligence. Presented here are some basic human intelligence concepts framed for Artificial Intelligence systems. These include concepts like Metacognition and Metamemory, along with architectural constructs for Artificial Intelligence versions of human brain functions like the prefrontal cortex. Also presented are possible hardware and software architectures that lend themselves to learning, reasoning, and self-evolution

  3. Radioactivity of some dried fruits

    Full text: Radioactivity radiation from natural and artificial sources often acts at the same time in complicated combinations and without exception on all inhabitants of our planet. Natural and artificial radioactive isotopes pass into living organism by biological chain: soil-water-air-plants-foodstuffs-person and can be sources of inside irradiation. Accumulation of radionuclides in living organism in large quantities limit permissible concentration (LPC) can lead to pathological changes in organism. With above mentioned at the radioecological investigations, researches and control of changes of radionuclides concentration in environmental objects have important interests. Investigations of determination of radioactivity of environmental objects, which began in 1960 by professor Muso Muminov are continued in the department of nuclear physics of Samarkand State University. We work out semiconducting gamma-spectrometric method of determination of radionuclides concentration in weak -active environmental samples. We investigated radioactivity of different samples of natural environment and generalized results. In this work the results of investigation of radioactivity of same dried fruits are presented. The spectra of ?-radiation of following dried fruits as grapes, apricot, apple and peach was investigated. In measured gamma-radiation spectra of these samples gamma-transitions of 226Ra, 232Th, 40K natural radionuclides and product of 137Cs division. The specific gamma-activities these radionuclides were determined. The 40K have most specific activity and 137Cs - least. The calculated quantities of specific gamma-activity of radionuclides in gamma-spectra of investigated samples can replace to following row: 40K > 232Th > 226Ra > 137Cs

  4. Radioactive Waste.

    Blaylock, B. G.

    1978-01-01

    Presents a literature review of radioactive waste disposal, covering publications of 1976-77. Some of the studies included are: (1) high-level and long-lived wastes, and (2) release and burial of low-level wastes. A list of 42 references is also presented. (HM)

  5. Radioactive wastes

    Included in the radioactive waste literature review for 1981 were three symposia summarized in four tables. The remaining literature has been divided into ten categories: general programs, isolation, waste treatment, waste management, storage, environmental transport, monitoring, transportation, risk assessment, remedial action, and socioeconomics. Included are 193 references

  6. Using gold nanoparticles as artificial defects in thin films: What have we learned about laser-induced damage driven by localized absorbers?

    Papernov, S.; Schmid, A. W.

    2007-01-01

    There is general agreement that localized absorbing defects are a major factor affecting thin-film performance, and laserinduced damage in films designed for UV, nanosecond-scale, pulsed-laser applications is driven by nanoscale absorbers. Low number densities and size (few nanometer), however, prevent any characterization of these defects and, consequently, deterministic film improvement. This situation also hampers further development of localized defectdriven damage theory, since initial conditions for modeling remain uncertain. Recently, a new approach for studying laser interaction with thin-film nanoscale defects was implemented in which well-characterized, isolated artificial absorbing defects (gold nanoparticles) were introduced inside the thin film. This work is a review in which we discuss main findings from experiments with gold nanoparticles, such as delocalization of absorption during the laser pulse, importance of the defect boundary conditions (contact with the matrix), and competition of pure thermal and stressdriven mechanisms of damage-crater formation. These experimental results will be compared with theoretical results of damage-crater formation in such model thin films using both phenomenological modeling and detailed calculations of the kinetics of the damage process. An outlook on future thin-film-damage studies using model systems with artificial defects is also presented.

  7. High energy muon induced radioactive nuclides in nickel plate and its use for 2-D muon-beam image profile

    Target materials were exposed to a muon beam with an energy of 160 GeV/c at the COMPASS experiment line in CERN-SPS to measure the production cross-sections for muon-induced radionuclides. A muon imager containing four nickel plates, each measuring 100 mm×100 mm, exposed to the IP plate successfully detected the muon beam image during an irradiation period of 33 days. The contrasting density rate of the nickel plate was (5.2±0.7)×10–9 PSL/muon per one-day exposure to IP. The image measured 122 mm and 174 mm in horizontal and vertical lengths, respectively, in relation to the surface of the base, indicating that 50±6% of the muon beam flux is confined to an area of 18% of the whole muon beam. The number of muons estimated from the PSL value in the total beam image area (0.81±0.1)×1013 was comparable to the total muon counts of the ion-chamber at the M2 beam line in the CERN-SPS. The production cross-sections of Cr-51, Mn-54, Co-56, Co-57, and Co-58 in nickel were 0.19±0.08, 0.34±0.06, 0.5±0.05, 3.44±0.07, 0.4±0.03 in the unit of mb, respectively, reducing muon associated particles effects. They are approximately 10 times smaller than that a proceeding study by Heisinger et al

  8. High energy muon induced radioactive nuclides in nickel plate and its use for 2-D muon-beam image profile

    Kurebayashi, Y. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Sakurai, H., E-mail: sakurail@sci.kj.yamagata-u.ac.jp [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Takahashi, Y. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Doshita, N. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Kikuchi, S. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Tokanai, F. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Horiuchi, K. [Graduate School of Science and Technology, Hirosaki University, 3, Bunkyo-chou, Hirosaki 036-8561, Aomori (Japan); Tajima, Y. [Institute of Arts and Sciences, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Oe, T. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Sato, T. [Graduate School of Science and Engineering, Yamagata University, Yamagata 990-8560 (Japan); Gunji, S. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Inui, E. [Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Kondo, K. [Department of Physics, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Iwata, N. [Dept. of Earth and Environmental Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560 (Japan); Sasaki, N. [Graduate School of Science and Technology, Hirosaki University, 3, Bunkyo-chou, Hirosaki 036-8561, Aomori (Japan); Matsuzaki, H. [Micro Analysis Laboratory, Tandem accelerator (MALT), The University Museum, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Kunieda, S. [Nuclear Data Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun 319-1195, Ibaraki (Japan)

    2015-11-01

    Target materials were exposed to a muon beam with an energy of 160 GeV/c at the COMPASS experiment line in CERN-SPS to measure the production cross-sections for muon-induced radionuclides. A muon imager containing four nickel plates, each measuring 100 mm×100 mm, exposed to the IP plate successfully detected the muon beam image during an irradiation period of 33 days. The contrasting density rate of the nickel plate was (5.2±0.7)×10{sup –9} PSL/muon per one-day exposure to IP. The image measured 122 mm and 174 mm in horizontal and vertical lengths, respectively, in relation to the surface of the base, indicating that 50±6% of the muon beam flux is confined to an area of 18% of the whole muon beam. The number of muons estimated from the PSL value in the total beam image area (0.81±0.1)×10{sup 13} was comparable to the total muon counts of the ion-chamber at the M2 beam line in the CERN-SPS. The production cross-sections of Cr-51, Mn-54, Co-56, Co-57, and Co-58 in nickel were 0.19±0.08, 0.34±0.06, 0.5±0.05, 3.44±0.07, 0.4±0.03 in the unit of mb, respectively, reducing muon associated particles effects. They are approximately 10 times smaller than that a proceeding study by Heisinger et al.

  9. Radioactivity Monitoring of the Irish Environment 2007

    This report presents the results of the environmental radioactivity monitoring programme carried out by the Radiological Protection Institute of Ireland (RPII) in 2007. This programme aims to assess the exposure of the Irish population to artificial radioactivity in the envorinment, to review the temporal and geographical distribution of contaminating radionuclides and to maintain systems and procedures which would allow a rapid assessment of environmental contamination to be made in the event of a radiological emergency. In additiopn, some natural radioactivity exposure pathways are included in the programme including radioactivity in surface and ground drinking water. Radioactivity is present in the environment due to natural oprocesses, the testing of nuclear weapons in the atmosphere, past nuclear accidents such as that at Chernobyl in the Ukraine and the routine discharge of radionuclides from nuclear installations. Liquid discharges from the British Nuclear Group reprocessing plant at Sellafield in Cumbria in the north-west of England continue to be the dominant source of artificial radioactivity in the Irish marine environment. The key elements of the monitoring programme implemented by the RPII in 2007 included; assessment of ambient radioactivity based on measurements of radioactivity in air and of external gamma dose rate at permanent monitoring stations located throughout the country; assessment of levels of radioactivity in drinking water; assessment of levels of radioactivity in foodstuffs based on measurements of total diet, milk and various ingredients; assessment of levels of radioactivity in the Irish marine environment based on sampling and measurement of seawater, sediment, seaweed, fish and shellfish. The RPII monitored airborne radioactivity at twelve stations located throughout the country. One of these stations is equipped with a high volume sampler, which allows background concentrations of caesium-137 to be measured; another is equipped to detect the presence of the gas krypton-85. This gas is released into the environment primarity as a result of the reprocessing of nuclear fuel. During 2007, levels of radionuclides in airborne radioactivity were low and consistent with measurements in previous years. External gamma dose rates were monitored continuously at fifteen stations. No abnormal levels were observed. A major upgrade of the aerosol sampling equipment began in 2007 when three on-line low volume systems and seven upgraded off-line low volume systems were installed and commissioned. Two additional on-line sites will be added in 2008. In accordance with the RPII's drinking water monitoring protocol, a number of major water supplies from Cork, Dublin, Galway and Limerick were tested and found to be within the requirements for radioactivity set out in the relevant national standards. In addition, groundwater supplies were tested in nine countries as a pilot for a national survey of ground water scheduled for 2008 to 2010. The RPII sampled and measured levels of radioactivity in mixed diet, milk and various other foodstuffs including milk products, baby foods, beef, lamb and poultry. These measurements show that the levels of artificual radioactivity in the Irish diet continue to be low. One hundred and ninety samples of fish, shellfish, seaweed, seawater and sediment were analysed for a range of radionuclides. Along the Irish coastline the highest activity concentrations observed were in the north-east. The main pathway contributing to the exposure of the Irish public to artificial radioactivity from the marine environment is the consumption of seafood. Caesium-137 continues to be the dominant radionuclide, accounting for approximately 84% of the total dose. The dose to the Irish population from consumption of seafood landed at north-east ports has declined significantly over the last two decades corresponding to the reduction in discharges from Sellafield. The annual doses incurred by the Irish public as a result of artificial radioactivity in the environment do not constitute a significant health risk and are small compared with the dose received as a result of natural radiation

  10. Artificial life and life artificialization in Tron

    Carolina Dantas Figueiredo

    2012-12-01

    Full Text Available Cinema constantly shows the struggle between the men and artificial intelligences. Fiction, and more specifically fiction films, lends itself to explore possibilities asking “what if?”. “What if”, in this case, is related to the eventual rebellion of artificial intelligences, theme explored in the movies Tron (1982 and Tron Legacy (2010 trat portray the conflict between programs and users. The present paper examines these films, observing particularly the possibility programs empowering. Finally, is briefly mentioned the concept of cyborg as a possibility of response to human concerns.

  11. Radioactive Cs in the estuary sediments near Fukushima Daiichi Nuclear Power Plant.

    Yamasaki, Shinya; Imoto, Junpei; Furuki, Genki; Ochiai, Asumi; Ohnuki, Toshihiko; Sueki, Keisuke; Nanba, Kenji; Ewing, Rodney C; Utsunomiya, Satoshi

    2016-05-01

    The migration and dispersion of radioactive Cs (mainly (134)Cs and (137)Cs) are of critical concern in the area surrounding the Fukushima Daiichi Nuclear Power Plant (FDNPP). Considerable uncertainty remains in understanding the properties and dynamics of radioactive Cs transport by surface water, particularly during rainfall-induced flood events to the ocean. Physical and chemical properties of unique estuary sediments, collected from the Kuma River, 4.0km south of the FDNPP, were quantified in this study. These were deposited after storm events and now occur as dried platy sediments on beach sand. The platy sediments exhibit median particle sizes ranging from 28 to 32μm. There is increasing radioactivity towards the bottom of the layers deposited; approximately 28 and 38Bqg(-1) in the upper and lower layers, respectively. The difference in the radioactivity is attributed to a larger number of particles associated with radioactive Cs in the lower part of the section, suggesting that radioactive Cs in the suspended soils transported by surface water has decreased over time. Sequential chemical extractions showed that ~90% of (137)Cs was strongly bound to the residual fraction in the estuary samples, whereas 60~80% of (137)Cs was bound to clays in the six paddy soils. This high concentration in the residual fraction facilitates ease of transport of clay and silt size particles through the river system. Estuary sediments consist of particles <100μm. Radioactive Cs desorption experiments using the estuary samples in artificial seawater revealed that 3.4±0.6% of (137)Cs was desorbed within 8h. More than 96% of (137)Cs remained strongly bound to clays. Hence, particle size is a key factor that determines the travel time and distance during the dispersion of (137)Cs in the ocean. PMID:26874771

  12. Influence of Artificial Sweetener on Human Blood Glucose Concentration

    Ilse Skokan; P. Christian Endler; Beatrix Wulkersdorfer; Dieter Magometschnigg; Heinz Spranger

    2007-01-01

    Artificial sweeteners, such as saccharin or cyclamic acid are synthetically manufactured sweetenings. Known for their low energetic value they serve especially diabetic and adipose patients as sugar substitutes. It has been hypothesized that the substitution of sugar with artificial sweeteners may induce a decrease of the blood glucose. The aim of this study was to determine the reliability of this hypothesis by comparing the influence of regular table sugar and artificial sweeteners on the b...

  13. Artificial insemination in poultry

    Artificial insemination is a relative simple yet powerful tool geneticists can employ for the propagation of economically important traits in livestock and poultry. In this chapter, we address the fundamental methods of the artificial insemination of poultry, including semen collection, semen evalu...

  14. Radioactive waste management

    This eighth chapter presents the radioactive wastes and waste disposal; classification of radioactive wastes; basis requests of the radioactive waste management; conditions for a radioactive waste disposal; registers and inventories; transport of radioactive wastes from a facility to another and the radioactive waste management plan

  15. Radioactive waste

    Focusing on radioactive waste management and disposal policies in the United Kingdom, Sweden and the Federal Republic of Germany, this book gives a detailed historical account of the policy process in these three countries, and draws out the implications for theory and public policy. This comparative approach underlines how profoundly different the policy process has been in different countries. By comparing the evolution of policy in three countries, fundamental questions about the formation and resolution of technical decisions under uncertainty are clarified. The analysis of nuclear strategy, the politics of nuclear power, and the shifting emphasis of government regulation redefines the issue of radwaste management and sets it at the heat of the current debate about power, the environment and society. The combination of up-to-date technological assessment with an account of the social and political implications of radwaste management makes'Radioactive Waste'particularly useful to students of environmental studies, geography and public administration. (author)

  16. Onion artificial muscles

    Chen, Chien-Chun; Shih, Wen-Pin; Chang, Pei-Zen; Lai, Hsi-Mei; Chang, Shing-Yun; Huang, Pin-Chun; Jeng, Huai-An

    2015-05-01

    Artificial muscles are soft actuators with the capability of either bending or contraction/elongation subjected to external stimulation. However, there are currently no artificial muscles that can accomplish these actions simultaneously. We found that the single layered, latticed microstructure of onion epidermal cells after acid treatment became elastic and could simultaneously stretch and bend when an electric field was applied. By modulating the magnitude of the voltage, the artificial muscle made of onion epidermal cells would deflect in opposing directions while either contracting or elongating. At voltages of 0-50 V, the artificial muscle elongated and had a maximum deflection of -30 ?m; at voltages of 50-1000 V, the artificial muscle contracted and deflected 1.0 mm. The maximum force response is 20 ?N at 1000 V.

  17. Radioactive alchemy

    Anon.

    2014-07-15

    For any entity involved in radioactive waste management, turning lead into gold means succeeding with minimising the volumes and optimizing the long-term containment of ultimate waste to be disposed of. With this purpose, they perform R and D on different sorting, treatment and disposal technology, as explained by Frederic Plas from Andra (France), Jan Deckers from Belgoprocess (Belgium) and Wilhelm Bollingerfehr from DBE Technology (Germany). (orig.)

  18. Gas and water flow in an excavation-induced fracture network around an underground drift: A case study for a radioactive waste repository in clay rock

    de La Vaissière, Rémi; Armand, Gilles; Talandier, Jean

    2015-02-01

    The Excavation Damaged Zone (EDZ) surrounding a drift, and in particular its evolution, is being studied for the performance assessment of a radioactive waste underground repository. A specific experiment (called CDZ) was designed and implemented in the Meuse/Haute-Marne Underground Research Laboratory (URL) in France to investigate the EDZ. This experiment is dedicated to study the evolution of the EDZ hydrogeological properties (conductivity and specific storage) of the Callovo-Oxfordian claystone under mechanical compression and artificial hydration. Firstly, a loading cycle applied on a drift wall was performed to simulate the compression effect from bentonite swelling in a repository drift (bentonite is a clay material to be used to seal drifts and shafts for repository closure purpose). Gas tests (permeability tests with nitrogen and tracer tests with helium) were conducted during the first phase of the experiment. The results showed that the fracture network within the EDZ was initially interconnected and opened for gas flow (particularly along the drift) and then progressively closed with the increasing mechanical stress applied on the drift wall. Moreover, the evolution of the EDZ after unloading indicated a self-sealing process. Secondly, the remaining fracture network was resaturated to demonstrate the ability to self-seal of the COx claystone without mechanical loading by conducting from 11 to 15 repetitive hydraulic tests with monitoring of the hydraulic parameters. During this hydration process, the EDZ effective transmissivity dropped due to the swelling of the clay materials near the fracture network. The hydraulic conductivity evolution was relatively fast during the first few days. Low conductivities ranging at 10-10 m/s were observed after four months. Conversely, the specific storage showed an erratic evolution during the first phase of hydration (up to 60 days). Some uncertainty remains on this parameter due to volumetric strain during the sealing of the fractures. The hydration was stopped after one year and cross-hole hydraulic tests were performed to determine more accurately the specific storage as well as the hydraulic conductivity at a meter-scale. All hydraulic conductivity values measured at the injection interval and at the observation intervals were all below 10-10 m/s. Moreover, the preferential inter-connectivity along the drift disappeared. Specific storage values at the observation and injection intervals were similar. Furthermore they were in agreement with the value obtained at the injection interval within the second hydration phase (60 days after starting hydration). The graphical abstract synthesizes the evolution of the hydraulic/gas conductivity for 8 intervals since the beginning of the CDZ experiment. The conductivity limit of 10-10 m/s corresponds to the lower bound hydraulic definition of the EDZ and it is demonstrated that EDZ can be sealed. This is a significant result in the demonstration of the long-term safety of a repository.

  19. Radioactivity monitor

    Purpose: To measure low-level radioactivity in an exhaust gas discharged from a nuclear power station. Constitution: Two valves are provided at two points of a pipe through which the exhaust gas is passed. The gas between two valves can be separated from gas in the other parts of the pipe. A bypass pipe is provided at the outer parts of the aforementioned two valves. The pipe at one side can be maintained in live state. In order to use the part isolated by the two valves as an ionization chamber, high insulators such as teflon and the like are provided at the inner sides of two valves. By applying a voltage of from 5 -- 600 to 5 -- 6000 volts to the isolated part thereby to collect ions inside the part, and the radioactivity is measured by the detection of beta-ray. Since the beta-ray is utilized, radioactive rays having short range can be measured with good efficiency. (Ikeda, J.)

  20. HUMAN EXPOSURE TO THE ARTIFICIAL RADIONUCLIDES IN ENVIRONMENT

    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.

  1. The natural radioactivity of the biosphere

    Of the approximately 1200 isotopes presently known more than 900 are radioactive. The nuclei of these isotopes are unstable and decay spontaneously emitting ionizing gamma-, alpha- or beta-radiation. The overwhelming majority of known radioactive isotopes have been obtained artificially; only a few are natural. Numerous investigations have shown that many of the natural radioactive isotopes can be grouped into three radioactive families. Each such family is characterized by the existence of one long-lived isotope - the family parent, one gaseous isotope of radon, intermediate radioactive decay products and final stable isotopes of atomic weights 206, 207 and 208. No such generic relationship has been established among the remaining natural radioactive isotopes. The purpose of the book, in contrast to some recent review works, is to present, in addition to a summary of reference data characterizing the radioactivity levels of various components of the biosphere, a description of those phenomena and regularities which will apparently make it possible to understand more completely the basic dynamics of the natural radioactivity of the biosphere and, consequently, contribute to a more correct interpretation of radiation-hygiene in each specific case

  2. Radioactivity in Hocking River Basin

    Numerous studies have examined the environmental impacts and health hazards associated with man-made radioactive pollution. Within the last decade, however, there has been a growing awareness of the natural radiation environment. Very little is know about the way the natural radiation environment is affected when subjected to artificial stresses imposed by man's activities. The prolonged exposure from low level radioactivity may significantly affect our environment by altering the distribution of naturally occurring radionuclides through such processes as mining, water resources management or land reclamation. It is the intent of this study to examine more closely the way in which this radiological burden is altered by coal mining activities in an Appalachian watershed

  3. Report 1995 to the Federal Council by the Commission for the Surveillance of the Radioactivity concerning the radioactivity in our environment

    Apart from the radon concentrations in approximately 1% of all houses in Switzerland which have a higher value than the limits which the radiation protection regulations permits, there is in Switzerland no acute threat due to artificial or natural radioactivity

  4. Radioactivity Monitoring of the Irish Environment 2008

    This report presents the results of the environmental radioactivity monitoring programme carried out by the Radiological Protection Institute of Ireland (RPII) during 2008. The RPII has routinely monitored levels of radioactivity in the environment since 1982 and this is the latest in the RPII's series of environmental monitoring reports. The RPII reviews and updates its environmental programme annually so as to ensure it remains relevant and continues to focus on the most important sources of radioactivity in the environment. The principal aims of the RPII's monitoring programme are; to assess the level of radioactivity to which the Irish population is exposed as a result of radioactivity in the environment; to study trends and establish the geographical distribution of contaminating radionuclides so as to better understand the long term behaviour of artificial radioactivity in the food chain and the environment; to ensure that any increase in radiation levels resulting from an accidental release of radioactivity to the environment is detected and assessed rapidly. During 2008 radioactivity was measured in a wide range of foods and environmental materials including: air, water, milk, seafood, foodstuffs and complete meals. The most significant source of artificial radioactivity in the Irish marine environment is the discharge of low level liquid radioactive waste from the Sellafield Nuclear Fuel Reprocessing Plant on the north east coast of England. In order to assess the exposure arising from the source extensive sampling of fish and shellfish landed at ports along the north east coast of Ireland is undertaken. The most exposed group of individuals to discharges from Sellafield have been identified as commercial oyster and mussel farmers working along the north east coastline and their families. Manmade radioactivity is also present in the terrestrial environment due primarily to residual global fallout arising primarily from atmospheric testing of nuclear weapons in the 1950s and 1960s and releases from past nuclear accidents such as Chernobyl. Milk, because it is an important foodstuff for infants and children and is known to concentrate long lived radionuclides such as caesium-137 and strontium-90, is an important indicator of levels of artificial radioactivity in the terrestrial food chain. The estimated dose due to strontium-90 activity in milk was estimated to be 0.55 ?Sv for 2008. This was for the most exposed group, assessed to be infants, children under the age of one year. It is very small compared to the background radiation. Radioactivity measurements on other foodstuffs confirm the levels of artificial radioactivity in the Irish food-chain remain very low and that Irish foodstuffs are free from harmful levels of radioactivity. The RPII monitors radioactivity in drinking water supplies in rotation so that major supplies from each county are sampled at least once every four years. During 2008 supplies from Carlow, Cavan, Clare, Cork, Donegal and Dublin were tested. Drinking water samples are assessed for compliance with the radioactivity standards set out in the Drinking Water Directive. All drinking water samples tested during 2008 were found to be in compliance with the radioactivity standards set out in the Drinking Water Directive. The RPII programme also monitors airborne radioactivity through its network of on- and off-line samplers. External gamma dose rates are also monitored. No exceptional activity was detected in outdoor air during 2008. The levels were consistent with those recorded in previous years. For 2008 the average annual dose from inhalation of caesium-137 was estimated at 8.0 x 10?? ?Sv. The data presented in this report confirm that while the levels of artificial radioactivity in the Irish environment are detectable they are low and are continuing to decrease. They do not pose a significant risk to the human health of the Irish population. Activity concentrations of radionuclides in airborne particulates were low and consistent with measurements made in recent years. Radioactivity levels in milk, mixed diet and a wide range of foodstuffs were low and, for the majority of samples, below the detection limits. All drinking waters tested for gross alpha and gross beta activities were found to comply with relevant national and EU standards for water quality. The doses incurred by the Irish public in 2008 as a result of artificial monitoring are small when compared to dose limits or to natural radiation doses received by the Irish public. The dose to the most exposed individuals, members of the oyster and mussel farmers critical group was approximately 0.04% of the annual dose limit of 1000 ?Sv for members of the public from practices involving controllable sources of radiation. These doses may be compared with the average annual dose to a person in Ireland from all sources of radioactivity of 3950 ?Sv. In general, levels of artificial radioactivity in the Irish environment remain fairly constant and are broadly consistent with levels reported previously. It must be emphasised that the levels of radioactive contamination present in the marine environment, do not warrant any modification of the habits of people in Ireland, either in respect of consumption of seafood or any other use of the amenities of the marine environment

  5. Radioactivity Monitoring of the Irish Environment 2009

    This report presents the results of the environmental radioactivity monitoring programme carried out by the Radiological Protection Institute of Ireland (RPII) during 2009. The RPII has routinely monitored levels of radioactivity in the environment since 1982 and this is the latest in the RPII's series of environmental monitoring reports. The RPII reviews and updates its environmental programme annually so as to ensure it remains relevant and continues to focus on the most important sources of radioactivity in the environment. The principal aims of the RPII's monitoring programme are; to assess the level of radioactivity to which the Irish population is exposed as a result of radioactivity in the environment; to study trends and establish the geographical distribution of contaminating radionuclides so as to better understand the long term behaviour of artificial radioactivity in the food chain and the environment; to ensure that any increase in radiation levels resulting from an accidental release of radioactivity to the environment is detected and assessed rapidly. During 2009 radioactivity was measured in a wide range of foods and environmental materials including: air, water, milk, seafood, foodstuffs and complete meals. The most significant source of artificial radioactivity in the Irish marine environment is the discharge of low level liquid radioactive waste from the Sellafield Nuclear Fuel Reprocessing Plant on the north east coast of England. In order to assess the exposure arising from the source extensive sampling of fish and shellfish landed at ports along the north east coast of Ireland is undertaken. The most exposed group of individuals to discharges from Sellafield have been identified as commercial oyster and mussel farmers working along the north east coastline and their families. Manmade radioactivity is also present in the terrestrial environment due primarily to residual global fallout arising primarily from atmospheric testing of nuclear weapons in the 1950s and 1960s and releases from past nuclear accidents such as Chernobyl. Milk, because it is an important foodstuff for infants and children and is known to concentrate long lived radionuclides such as caesium-137 and strontium-90, is an important indicator of levels of artificial radioactivity in the terrestrial food chain. The estimated dose due to strontium-90 activity in milk was estimated to be 0.97 ?Sv for 2009. This was for the most exposed group, assessed to be infants, children under the age of one year. It is very small compared to the background radiation. Radioactivity measurements on other foodstuffs confirm the levels of artificial radioactivity in the Irish food-chain remain very low and that Irish foodstuffs are free from harmful levels of radioactivity. The RPII monitors radioactivity in drinking water supplies in rotation so that major supplies from each county are sampled at least once every four years. During 2009 supplies from Galway, Kerry, Kildare, Kilkenny, Leitrim, Longford, Limerick and Laois were tested. Drinking water samples are assessed for compliance with the radioactivity standards set out in the Drinking Water Directive. All drinking water samples tested during 2009 were found to be in compliance with the radioactivity standards set out in the Drinking Water Directive. The RPII programme also monitors airborne radioactivity through its network of on- and off-line samplers. External gamma dose rates are also monitored. No exceptional activity was detected in outdoor air during 2009. The levels were consistent with those recorded in previous years. For 2009 the average annual dose from inhalation of caesium-137 was estimated at 9.0 x 10?? ?Sv. The data presented in this report confirm that while the levels of artificial radioactivity in the Irish environment are detectable they are low and are continuing to decrease. They do not pose a significant risk to the human health of the Irish population. Activity concentrations of radionuclides in airborne particulates were low and consistent with measurements made in recent years. Radioactivity levels in milk, mixed diet and a wide range of foodstuffs were low and, for the majority of samples, below the detection limits. All drinking waters tested for gross alpha and gross beta activities were found to comply with relevant national and EU standards for water quality. The doses incurred by the Irish public in 2009 as a result of artificial monitoring are small when compared to dose limits or to natural radiation doses received by the Irish public. The dose to the most exposed individuals, members of the oyster and mussel farmers critical group was approximately 0.04% of the annual dose limit of 1000 ?v for members of the public from practices involving controllable sources of radiation. These doses may be compared with the average annual dose to a person in Ireland from all sources of radioactivity of 3950 ?Sv. In general, levels of artificial radioactivity in the Irish environment remain fairly constant and are broadly consistent with levels reported previously. It must be emphasised that the levels of radioactive contamination present in the marine environment, do not warrant any modification of the habits of people in Ireland, either in respect of consumption of seafood or any other use of the amenities of the marine environment

  6. On the formation of non-radioactive copper during the production of 64Cu via proton and deuteron-induced nuclear reactions on enriched 64Ni targets

    Routine production of 64Cu commonly exploits the 64Ni(p,n) or 64Ni(d,2n) reactions. Above specific threshold energies, however, non-radioactive 63Cu and/or 65Cu are also co-produced. The non-radioactive (cold) Cu can significantly decrease the specific activity (SA) of 64Cu-labelled radiopharmaceuticals. Based on nuclear model calculations for the formation of non-radioactive Cu isotopes, theoretical specific activities (TSA) for 64Cu were estimated. Reported current production methods, however, often yield SA values that are lower than the corresponding TSA predictions by more than an order of magnitude. Most of the non-radioactive Cu causing this has been found to originate from sources other than co-production, indicating that there is still significant potential for method improvement. (author)

  7. Artificial intelligence in medicine.

    Ramesh, A. N.; Kambhampati, C.; Monson, J. R. T.; Drew, P. J.

    2004-01-01

    INTRODUCTION: Artificial intelligence is a branch of computer science capable of analysing complex medical data. Their potential to exploit meaningful relationship with in a data set can be used in the diagnosis, treatment and predicting outcome in many clinical scenarios. METHODS: Medline and internet searches were carried out using the keywords 'artificial intelligence' and 'neural networks (computer)'. Further references were obtained by cross-referencing from key articles. An overview of different artificial intelligent techniques is presented in this paper along with the review of important clinical applications. RESULTS: The proficiency of artificial intelligent techniques has been explored in almost every field of medicine. Artificial neural network was the most commonly used analytical tool whilst other artificial intelligent techniques such as fuzzy expert systems, evolutionary computation and hybrid intelligent systems have all been used in different clinical settings. DISCUSSION: Artificial intelligence techniques have the potential to be applied in almost every field of medicine. There is need for further clinical trials which are appropriately designed before these emergent techniques find application in the real clinical setting. PMID:15333167

  8. Ensuring radioactivity monitoring in the French Polynesia environment

    The Laboratory of Environmental Study and Monitoring (LESE) of the French Institute of Radiation Protection and Nuclear Safety (IRSN) at Vairao (Tahiti, French Polynesia), has been performing a permanent monitoring of radioactivity in French Polynesia for more than 40 years. This mission has two objectives: - the follow up of radioactivity levels of artificial origin in all environments where Polynesian populations are living, as well as the radioactivity of the food products they consume; - the estimate of the doses received by the Polynesian populations exposed to this radioactivity. This plaquette briefly presents these two missions

  9. Radioactive nuclides in the living environment

    There are several radioactive nuclides in the living environment, such as those existing since the creation of the earth, those coming from experimental nuclear explosions, and radiations of the cosmic rays. A lesson on these radioactive nuclides was considered useful for understanding the place of nuclear technology, and have been made on the title of 'Radioactive Nuclides in the Living Environment' in the general course of the Nuclear Engineering School of Japan Atomic Energy Research Institute. When the curriculum of the general course was modified in 1993, the lesson was left in a changed form. Thus, the textbook of the lesson is presented in this report. The contents are natural and artificial radioactive nuclides in the living environment and where they have come from etc. (author)

  10. Occurence of natural and artificial radionuclides in the environment and methods of their detection

    The authors discuss occurence of radionuclides in the environment and illustrate the circulation of natural and artificial radioactive substances in the air, water and soil. Methods are presented of detecting radioactive contamination, including the sampling and detection of radiation emitted by radioactive isotopes contained in the samples. Various conditions as well as the kind of ionizing radiation emitters are taken into consideration. 19 refs. (author)

  11. Gene Silencing Using 4'-thioDNA as an Artificial Template to Synthesize Short Hairpin RNA Without Inducing a Detectable Innate Immune Response.

    Tarashima, Noriko; Ando, Hidenori; Kojima, Takamitsu; Kinjo, Nozomi; Hashimoto, Yosuke; Furukawa, Kazuhiro; Ishida, Tatsuhiro; Minakawa, Noriaki

    2016-01-01

    The development of a versatile technique to induce RNA interference (RNAi) without immune stimulation in vivo is of interest as existing approaches to trigger RNAi, such as small interfering RNA (siRNA) and plasmid DNA (pDNA) expressing short hairpin RNA (shRNA), present drawbacks arising from innate immune stimulation. To overcome them, an intelligent shRNA expression device (iRed) designed to induce RNAi was developed. The minimum sequence of iRed encodes only the U6 promoter and shRNA. A series of iRed comprises a polymerase chain reaction (PCR)-amplified 4'-thioDNA in which any one type of adenine (A), guanine (G), cytosine (C), or thymine (T) nucleotide unit was substituted by each cognate 4'-thio derivatives, i.e., dSA iRed, dSG iRed, dSC iRed, and ST iRed respectively. Each modified iRed acted as a template to transcribe shRNA with RNAi activity. The highest shRNA yield was generated using dSC iRed that exerted gene silencing activity in an orthotopic mouse model of mesothelioma. Reducing the minimal structure required to transcribe shRNA and the presence of the 4'-thiomodification synergistically function to abrogate innate immune response induced by dsDNA. The iRed will introduce a new approach to induce RNAi without inducing a detectable innate immune response. PMID:26730811

  12. Radioactive dating

    The history of radioactive dating methods and their impact on such scientific fields as archaeology, geology, hydrology, climatology, and environmental protection are described. Significant advances in understanding have resulted from their application, and current and future developments promise exciting advances in the areas of application and the available age ranges. New techniques, capable of determining the ages of extremely small (milligram) samples, are described allowing reliable dates to be determined for, amongst other things, art or religious treasures, previously forbidden because of the size of sample required. Enrichment techniques, e.g. using lasers, allow extension of the range of radiocarbon dating, and equipment developments allow more accurate measurements to be made. (author)

  13. Radioactivity telemetry

    The authors present an assembly which aims at radio-transmitting from mobile stations information on radioactivity. It comprises 20 mobile stations which can be located within the Cadarache Centre or outside of it within a 10 km radius, and a central station which centralises information. The report proposes a general presentation of these stations, their characteristics and principles of operation. It describes operation sequences, central station functions (call programmer, address and memory management, recording, peripherals) and its energy supply, and mobile station functions. The last part presents the installation, its start-up and exploitation, its threshold devices and its safety device

  14. Developing Creativity: Artificial Barriers in Artificial Intelligence

    Jennings, Kyle E.

    2010-01-01

    The greatest rhetorical challenge to developers of creative artificial intelligence systems is convincingly arguing that their software is more than just an extension of their own creativity. This paper suggests that “creative autonomy,” which exists when a system not only evaluates creations on its own, but also changes its standards without explicit direction, is a necessary condition for making this argument. Rather than requiring that the system be hermetically sealed to avoid perceptions...

  15. Melting artificial spin ice

    Artificial spin ice arrays of micromagnetic islands are a means of engineering additional energy scales and frustration into magnetic materials. Here we demonstrate a magnetic phase transition in an artificial square spin ice and use the symmetry of the lattice to verify the presence of excitations far below the ordering temperature. We do this by measuring the temperature-dependent magnetization in different principal directions and comparing it with simulations of idealized statistical mechanical models. Our results confirm a dynamical pre-melting of the artificial spin ice structure at a temperature well below the intrinsic ordering temperature of the island material. We thus create a spin ice array that has the real thermal dynamics of artificial spins over an extended temperature range. (paper)

  16. Development and application of artificial rainfall device

    An artificial sprinkling simulation device was designed and developed to be used for radioactive nuclides migration tests. In this device water drops are sprinkled through medical syringe needles which vibrate along a circle. After several year operation at the field test site, it was demonstrated that this device is stable and sprinkling homogeneous, with the rainfall intensity from 2 mm/h to 100 mm/h and the low limit of 2 mm/h. Compared with spraying nozzle, it is easy to control the rainfall quantity and sprinkling area, and the evaporation loss is small. The device can meet the requirement of radioactive nuclide migration test and may also be used for other purpose

  17. Artificial intelligence in medicine.

    Ramesh, A. N.; C. Kambhampati; Monson, J. R. T.; Drew, P. J.

    2004-01-01

    INTRODUCTION: Artificial intelligence is a branch of computer science capable of analysing complex medical data. Their potential to exploit meaningful relationship with in a data set can be used in the diagnosis, treatment and predicting outcome in many clinical scenarios. METHODS: Medline and internet searches were carried out using the keywords 'artificial intelligence' and 'neural networks (computer)'. Further references were obtained by cross-referencing from key articles. An overview of ...

  18. Artificial Intelligence in Games

    Raju; Nitin Sikka; Sanjeev Kumar,; Rahul Gupta

    2012-01-01

    Based on the recent surge in interest in the both academic and games industry in character- based artificial intelligence. Although the games are mainly related with entertainments, but with this there are other serious applications of gaming, including military training, educational games, driving training, medical training and games that reflect social consciousness or advocate for a cause. Artificial intelligence in games is a concept of taking game applications beyond the lim...

  19. Principles of artificial intelligence

    Nilsson, Nils J

    1980-01-01

    A classic introduction to artificial intelligence intended to bridge the gap between theory and practice, Principles of Artificial Intelligence describes fundamental AI ideas that underlie applications such as natural language processing, automatic programming, robotics, machine vision, automatic theorem proving, and intelligent data retrieval. Rather than focusing on the subject matter of the applications, the book is organized around general computational concepts involving the kinds of data structures used, the types of operations performed on the data structures, and the properties of th

  20. Artificial Left Ventricle

    Ranjbar, Saeed; Meybodi, Tohid Emami; Meybodi, Mahmood Emami

    2014-01-01

    This Artificial left ventricle is based on a simple conic assumption shape for left ventricle where its motion is made by attached compressed elastic tubes to its walls which are regarded to electrical points at each nodal .This compressed tubes are playing the role of myofibers in the myocardium of the left ventricle. These elastic tubes have helical shapes and are transacting on these helical bands dynamically. At this invention we give an algorithm of this artificial left ventricle constru...

  1. The total artificial heart

    Cook, Jason A.; Shah, Keyur B.; Quader, Mohammed A.; Cooke, Richard H.; Kasirajan, Vigneshwar; Rao, Kris K.; Smallfield, Melissa C.; Tchoukina, Inna; Tang, Daniel G.

    2015-01-01

    The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient’s native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantati...

  2. Uranium and radioactivity

    The article gives results of investigations on uranium content and the proportion of induced and natural radioactivity in wines of different vines and regions. The ecological chain of ground, vine, grape, grape-juice, and wine is described, and the author shows that 14C and T measurements can be used to determine the age of wines with the aim of detecting adulterated vintages and blends of different years. The 14C and T content also indicates a direct connection with nuclear explosions. (RB/AK)

  3. Radioactivity and Environment. Radioactividad y Medio Ambiente

    Sanchez Leon, J.G. (Jefe de Seguridad Nuclear de la Fabrica de Juzbado. Empresa Nacional de Uranio. (Spain))

    1993-01-01

    Radioactivity is one of the most studied natural phenomena. Most of irradiation suffered by the human being is produced by natural sources. The second source in order of importance is nuclear medicine. The average level of radiation received by the man is 2.4 mSv/year and this value can be modified naturally in 20-30%. The author provides a review on radioactivity sources like natural (cosmic rays, extraterrestrial radiation, internal earth radiation, radon) and artificial (Nuclear explosions, professional exposure, nuclear medicine, nuclear power plants and accidents).

  4. Artificial skin. Jinko hifu

    Kifune, K. (Unitika Ltd., Osaka (Japan))

    1993-06-15

    In order to restore the human skin wounds, the transplantation is only one measure. The transplantation can take only when own skin is used, and there is no successful example by using other person's skin. When the own skin is not sufficient due to the too vast damage, the artificial skin, which can be regenerated as it is, is required. The artificial skin is said to be the most difficult organ among the artificial organs, even though its function is quite simple. Although there are the pig skin, the collagen membrane and the synthetic materials such as the polyurethane and so forth, as the materials similar to the artificial skin, they cover the wounds just until the cuticle is formed. Recently there is a cultivated skin. Firstly the normal skin with a size of the stamp is cut off, and then the cuticle cells are taken to pieces and cultivated, and consequently it is possible to increase the area by several 10 times. In addition, there is also a trial to make the artificial skin synthetically. Its upper layer is composed of the silicon, and the lower layer is the collagen membrane with a sponge structure. The silicon, membrane can be said to be an ideal artificial skin, because it detaches naturally. The chitin, which has recently appeared as the wound protection material, is also the promising material. 3 figs.

  5. Dissociation of Vertical Semiconductor Diatomic Artificial Molecules

    We investigate the dissociation of few-electron circular vertical semiconductor double quantum dot artificial molecules at 0T as a function of interdot distance. A slight mismatch introduced in the fabrication of the artificial molecules from nominally identical constituent quantum wells induces localization by offsetting the energy levels in the quantum dots by up to 2meV, and this plays a crucial role in the appearance of the addition energy spectra as a function of coupling strength particularly in the weak coupling limit

  6. Mathematical problems in modeling artificial heart

    Ahmed N. U.

    1995-01-01

    In this paper we discuss some problems arising in mathematical modeling of artificial hearts. The hydrodynamics of blood flow in an artificial heart chamber is governed by the Navier-Stokes equation, coupled with an equation of hyperbolic type subject to moving boundary conditions. The flow is induced by the motion of a diaphragm (membrane) inside the heart chamber attached to a part of the boundary and driven by a compressor (pusher plate). On one side of the diaphragm is the blood and on t...

  7. Radioactivity values in the river Elbe

    The largest portion of artificially produced radionuclides that currently gets into the river Elbe still stems from the fallout of supra-terrestrial atom bomb tests carried through decades ago in part. On the basis of a longitudinal profile of the Elbe from Schnackenburg to the Elbe estuary, no measurable increases were ascertained in the course of the systematic investigations pointing to artificial radionuclides of regional origin. This is also true of the nuclear power plants situated on the river Elbe. The amounts of radioactive nuclides, accurately known from emission measurements, which are discharged with sewage water from the Stade and Brunsbuettel nuclear power plants and reach the Elbe are so slight that they result in no measurable increase in radioactive nuclide levels in the Elbe. This is confirmed by the theoretical calculation. (orig./PW)

  8. Radioactive colloids

    Different techniques for the characterization of radioactive colloids, used in nuclear medicine, have been evaluated and compared. Several radioactive colloids have been characterized in vitro and in vivo and tested experimentally. Colloid biokinetics following interstitial or intravenous injection were evaluated with a scintillation camera technique. Lymphoscintigraphy with a Tc-99-labelled antimony sulphur colloid was performed in 32 patients with malignant melanoma in order to evaluate the technique. Based on the biokinetic results, absorbed doses in tissues and organs were calculated. The function of the reticuloendothelial system has been evaluated in rats after inoculation with tumour cells. Microfiltration and photon correlation spectroscopy were found to be suitable in determining activity-size and particle size distributions, respectively. Maximal lymph node uptake following subcutaneous injection was found to correspond to a colloid particle size between 10 and 50 nm. Lymphoscintigraphy was found to be useful in the study of lymphatic drainage from the primary tumour site in patients with malignant melanoma on the trunk. Quantitative analysis of ilio-inguinal lymph node uptake in patients with malignant melanoma on the lower extremities was, however, found to be of no value for the detection of metastatic disease in lymph nodes. High absorbed doses may be received in lymph nodes (up to 1 mGy/MBq) and at the injection site (about 10 mGy/MBq). In an experimental study it was found that the relative colloid uptake in bone marrow and spleen depended on the total number of intravenously injected particles. This may considerably affect the absorbed dose in these organs. (author)

  9. Radioactivity control of sediments in Serbia rivers

    In this paper we present the results of radioactivity control of the sediments in Serbian rivers from 2005 to 2008. Activity concentration of natural radionuclides in sediments (mean annual values in Bq/kg) in period 2005-2008 are within the average values limits on the territory of Serbia. Activities of long living radionuclide of artificial origin have tendency of mild decrease as a result of dissolution, leaching and changes in river flow. (author)

  10. Radioactivity analyses of food and drinking water in China following the Fukushima nuclear accident

    Objective: To summarize the analytical results of radioactivity in the food and drinking water nationwide following the Fukushima nuclear accident, and to evaluate its possible contamination to the public health in China. Methods: According to the national standard methods and IAEA, FDA correlative references,the scheme was established on sampling and measurements in food and drinking water after the breakout of the accident. The quality control was requested on the sampling, analyses and data report. Results: Trace artificial radioactive isotope of 131I was measured in spinach samples on 2 April 2011 in Beijing. Subsequently 131I was found in 10 kinds of growing leaves vegetables (open field)nationwide. The maximum detectable activity of 131I in vegetables was about 3.1 Bq/kg. Since 3 May 2011, the concentration of 131I has been below the detection limits.No artificial radionuclide was detectable in all of milk, drinking water and marine products samples during March to December, 2011. Conclusions: The food and drinking water measurements in China following the Fukushima nuclear accident denoted that the minor amounts of 131I in vegetables might result in very low absorbed dose and induce no impact on human health. The maximum detectable activity of 131I in vegetables was close to that reported in European countries,and much less than that measured in China immediately after the Chernobyl accident in 1986. (authors)

  11. Experimental studies on utilization of argonless artificial air

    The radioactive argon produced in nuclear reactors causes environmental pollution. One of the substantial methods to reduce radioactive argon is the utilization of the artificial air with low argon content in reactor rooms. The artificial air close to natural air is obtainable by mixing commercial oxygen and nitrogen, however, there are some technical problems to be solved before it is solved. A small scale facility supplying artificial air was manufactured for trial, in order to find the optimum condition of controlling the mixing and to develop the continuous measurement method for the argon concentration in artificial air. In this study, the following facts have been found. For providing with the argonless artificial air close to natural air, the mixing of the gases evaporating from commercial liquid oxygen and nitrogen can be safely controlled. For the mixing control covering the wide range of flow rate, it is necessary to set up an auxiliary line in low flow range, in addition to the ordinary main line. The method of controlling the flow ratio of oxygen and nitrogen is not suitable to the control in low flow range. The oxygen concentration control method detecting it continuously is applicable to the control of whole flow range. The argon concentration is measured with an X-ray emission spectrometer. (Kako, I.)

  12. Artificial Intelligence in Games

    Raju

    2012-11-01

    Full Text Available Based on the recent surge in interest in the both academic and games industry in character- based artificial intelligence. Although the games are mainly related with entertainments, but with this there are other serious applications of gaming, including military training, educational games, driving training, medical training and games that reflect social consciousness or advocate for a cause. Artificial intelligence in games is a concept of taking game applications beyond the limits of interactive gaming. Such system learn about the player’s behaviours during game play and beyond the pre-programmed set provides and interactively develop and provide a best experience to the players.General Terms The main aim of our research is to develop such artificial intelligence techniques that can have a substantial impact in the game industry. In the following research paper we are going to study about Case Based Reasoning (CBR, automatic behaviour adjustment for believing characters, drama management and user modelling for interactive stories and strategic behaviour planning for real time strategy games. We include problems in adopting artificial intelligence in games and some algorithms for respective games. Future aspect of artificial intelligence in games is also mentioned in the paper.

  13. Radiation-induced evolution of gas in neutral and alkaline aqueous solutions of sodium nitrate and sodium acetate simulating liquid radioactive wastes

    Gas release in neutral and alkaline aqueous solutions of sodium nitrate and sodium acetate, simulating liquid radioactive wastes, is studied. Yields of hydrogen, methane, carbon dioxide and nitrogen-containing gases are determined in dependence on the solution composition. Possible sources of these gases formation are discussed

  14. Natural and artificial radioactivity in soils of forests

    Levels of 222 Rn, 40 K, 235 U, 226 Ra and 137 Cs were studied in soils of a forest zone located at 3000 m altitude in the central portion of Mexico. the radon concentrations in different soil horizons were determined with solid state nuclear track detectors and the concentrations of 40 K, 235 U, 226 Ra and 137 Cs in soil samples were measured with a gamma spectrometer at low level coupled to a High purity Ge detector. The results indicate differences of a magnitude order in the radon concentrations inside the studied area. The levels of 40 K, 235 U, 226 Ra and 137 Cs are discussed as function of the perturbation grade of the soil and atmospheric pollution. (Author)

  15. Artificial radioactivity of waters of the Mediterranean Sea

    Cs-137 concentration measurements in surface waters of the Mediterranean and Black Seas, obtained in the R/V 'Gorizont' cruise (May - June 1998), are described. The annual Cs-137 inputs to the Mediterranean Sea from the Black Sea since 1959 till 1998 are estimated

  16. Monitoring Radioactivity in the Environment Under Routine and Emergency Conditions

    Marc, De Cort

    2011-01-01

    The main purpose of environmental monitoring is to quantify the levels of radioactivity in the various compartments of the environment disregarding its origin: natural or anthropo-genic, under routine or accidental conditions, in view of the health effects on man and his environment. However, because of their historical background, which is connected to the development of nuclear industry, the monitoring programmes established in the European countries focus on artificial radioactivity. M...

  17. The Ospar convention and its implementation: radioactive substances

    In the final analysis, it appears that the objectives that have been set, either in general or for the year 2020, are to achieve concentrations of artificial radioactive substances in the environment that are close to zero and not to achieve discharge levels that are close to zero. This objective must be met through a programmed reduction of radioactive discharges that takes into account of criteria relating to technical feasibility and radiological impact. (N.C.)

  18. An Assessment of Radioactivity of Selected Industrial Waste

    phosphogypsum (phph) is a by-product in the manufacture of phosphoric acid for the artificial fertilizer industry. In the present work, qualitative and quantitative radioactive analysis are carried for phph of National Company of Abuzabal for chemical fertilizers. Gamma ray spectroscopy techniques are applied. The present study reveals that the radioactivity resulted from these wastes is out of the international standards, and it is strongly not recommended to be used as a construction material or for dwellings

  19. Generalised Derived Limits for Selected Artificial Radionuclides in Foodstruffs

    The calculation of generalised derived limits for selected artificial radionuclides in foodstuffs consumed by the Indonesians have been carried out. The calculations is based on annual dose limit of 1 mSv for members of the public and the data on dose equivalent per unit of intake for the respective radionuclides, whilst the data of food consumption were taken from a survey conducted by The Central Bureau of Statistics. The generalised derived limits presented, as well as the derived investigation which the results of artificial radioactivity level monitoring in environmental foodstuffs can be compared. (author). 12 refs., 4 tabs

  20. Artificial intelligence in nanotechnology

    Sacha, G. M.; Varona, P.

    2013-11-01

    During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines.

  1. Artificial muscles on heat

    McKay, Thomas G.; Shin, Dong Ki; Percy, Steven; Knight, Chris; McGarry, Scott; Anderson, Iain A.

    2014-03-01

    Many devices and processes produce low grade waste heat. Some of these include combustion engines, electrical circuits, biological processes and industrial processes. To harvest this heat energy thermoelectric devices, using the Seebeck effect, are commonly used. However, these devices have limitations in efficiency, and usable voltage. This paper investigates the viability of a Stirling engine coupled to an artificial muscle energy harvester to efficiently convert heat energy into electrical energy. The results present the testing of the prototype generator which produced 200 μW when operating at 75°C. Pathways for improved performance are discussed which include optimising the electronic control of the artificial muscle, adjusting the mechanical properties of the artificial muscle to work optimally with the remainder of the system, good sealing, and tuning the resonance of the displacer to minimise the power required to drive it.

  2. An artificial molecular pump

    Cheng, Chuyang; McGonigal, Paul R.; Schneebeli, Severin T.; Li, Hao; Vermeulen, Nicolaas A.; Ke, Chenfeng; Stoddart, J. Fraser

    2015-06-01

    Carrier proteins consume fuel in order to pump ions or molecules across cell membranes, creating concentration gradients. Their control over diffusion pathways, effected entirely through noncovalent bonding interactions, has inspired chemists to devise artificial systems that mimic their function. Here, we report a wholly artificial compound that acts on small molecules to create a gradient in their local concentration. It does so by using redox energy and precisely organized noncovalent bonding interactions to pump positively charged rings from solution and ensnare them around an oligomethylene chain, as part of a kinetically trapped entanglement. A redox-active viologen unit at the heart of a dumbbell-shaped molecular pump plays a dual role, first attracting and then repelling the rings during redox cycling, thereby enacting a flashing energy ratchet mechanism with a minimalistic design. Our artificial molecular pump performs work repetitively for two cycles of operation and drives rings away from equilibrium toward a higher local concentration.

  3. Artificial intelligence in nanotechnology

    During the last decade there has been increasing use of artificial intelligence tools in nanotechnology research. In this paper we review some of these efforts in the context of interpreting scanning probe microscopy, the study of biological nanosystems, the classification of material properties at the nanoscale, theoretical approaches and simulations in nanoscience, and generally in the design of nanodevices. Current trends and future perspectives in the development of nanocomputing hardware that can boost artificial-intelligence-based applications are also discussed. Convergence between artificial intelligence and nanotechnology can shape the path for many technological developments in the field of information sciences that will rely on new computer architectures and data representations, hybrid technologies that use biological entities and nanotechnological devices, bioengineering, neuroscience and a large variety of related disciplines. (topical review)

  4. Environmental radioactivity and radiation exposure

    The environmental radioactivity in the Federal Republic of Germany was almost as high in 1976 as in 1975. It only increased temporarily in autumn 1976 as a result of the above-ground nuclear weapons test of the People's Republic of China on September 29th 1976 and then returned to its previous level. The radioactivity in food had a slight decreasing trend in 1976, apart from a temporary increase in the radioactivity in milk also caused by the nuclear weapons test mentioned. The population exposure remains basically unchanged in 1976 compared with 1975. The artificial radiation exposure is about half as high as the natural radiation exposure to which man has always been exposed. The former is based to 83% on using X-rays in medicine, particularly for X-ray diagnostic purposes. The population exposure due to nuclear power plants and other nuclear plants is still well below 1% of the natural radiation exposure although in 1976 three new nuclear power plants were put into operation. This is also true for the average radiation exposure within an area of 3 km around the nuclear plant. (orig.)

  5. Studies on the utility of artificial mutations in plant breeding, 16: Gene analysis of male sterility induced in rice [Oryza sativa

    Eleven male-sterile mutants were induced from a rice variety Sasanishiki by ethyleneimine and ?-ray treatments of seeds. Nine of them produced no pollen grains or only abortive ones and the other two showed extremely low pollen fertilities. The eleven mutants were crossed with the original variety. All F1 hybrids were fertile, i.e., normal in both pollen and seed fertilities. In eight of their F2 progenies, fertile and male-sterile plants segregated in a ratio of 3 to 1, indicating that the male sterility of the eight mutants was controlled by a single recessive gene. In one of the other three, segregation ratio suggested the participation of two recessive genes, while in the remaining two, the number of the genes responsible for male sterility could not be determined. (author)

  6. Radioactive decontamination

    It discusses radioactive decontamination from the practical point of view with aim of contributions to safety control of radioisotopes. As general knowledges, contamination forms are explained from physical states of solid materials' surfaces and classification of contaminative mechanism are conducted in each contamination form. Furthermore, the decontaminants selcted for each classified contaminative mechanism are indicated from pH-effect and concentration effect. Decontamination on laboratory, using wet method generally as a decontamination technic includes irrigation method by decontaminant solution and scrubbing method. Decontamination of machinery and tools includes scrubbing method and the methods using ultrasonic decontamination equipment and semiautomatic decontamination equipment of which flow-diagram is illustrated. The methods of decontamination of clothing include its disposal or the use of tightly-closed full automatic washing machine. The general irrigation method are indicated as decontamination of skin. Furthermore, neutral cleaning material method for elimination of short-term elapsed contamination and Titanium oxide paste method for elimination of long-term elapsed contamination are explained. (Kanao, N.)

  7. Bayesian artificial intelligence

    Korb, Kevin B

    2003-01-01

    As the power of Bayesian techniques has become more fully realized, the field of artificial intelligence has embraced Bayesian methodology and integrated it to the point where an introduction to Bayesian techniques is now a core course in many computer science programs. Unlike other books on the subject, Bayesian Artificial Intelligence keeps mathematical detail to a minimum and covers a broad range of topics. The authors integrate all of Bayesian net technology and learning Bayesian net technology and apply them both to knowledge engineering. They emphasize understanding and intuition but also provide the algorithms and technical background needed for applications. Software, exercises, and solutions are available on the authors' website.

  8. Spatially Resolved Artificial Chemistry

    Fellermann, Harold

    2009-01-01

    Although spatial structures can play a crucial role in chemical systems and can drastically alter the outcome of reactions, the traditional framework of artificial chemistry is a well-stirred tank reactor with no spatial representation in mind. Advanced method development in physical chemistry has...... made a class of models accessible to the realms of artificial chemistry that represent reacting molecules in a coarse-grained fashion in continuous space. This chapter introduces the mathematical models of Brownian dynamics (BD) and dissipative particle dynamics (DPD) for molecular motion and reaction...

  9. Artificial Enzymes, "Chemzymes"

    Bjerre, Jeannette; Rousseau, Cyril Andre Raphaël; Pedersen, Lavinia Georgeta M; Bols, Mikael

    2008-01-01

    successfully perform Michaelis-Menten catalysis under enzymatic conditions (i.e., aqueous medium, neutral pH, ambient temperature) and for those that do, very high rate accelerations are seldomly seen. This review will provide a brief summary of the recent developments in artificial enzymes, so called...... "Chemzymes", based on cyclodextrins and other molecules. Only the chemzymes that have shown enzyme-like activity that has been quantified by different methods will be mentioned. This review will summarize the work done in the field of artificial glycosidases, oxidases, epoxidases, and esterases, as well as...

  10. A study of marine zoo-benthos of OM attouyour (systematic, ecology and radioactivity)

    This study introduces a survey of marine zoo-Benthos found in the littoral zone of Om Attouyour. Measuring natural and artificial radioactivity. Likewise, artificial radionuclides levels and Hg, Pb, Cd, Zn, and Cu concentrations were low or within the range measured for similar samples in other coasts of the Mediterranean. (author)

  11. Estimation of the chemical-induced eye injury using a weight-of-evidence (WoE) battery of 21 artificial neural network (ANN) c-QSAR models (QSAR-21): part I: irritation potential.

    Verma, Rajeshwar P; Matthews, Edwin J

    2015-03-01

    Evaluation of potential chemical-induced eye injury through irritation and corrosion is required to ensure occupational and consumer safety for industrial, household and cosmetic ingredient chemicals. The historical method for evaluating eye irritant and corrosion potential of chemicals is the rabbit Draize test. However, the Draize test is controversial and its use is diminishing - the EU 7th Amendment to the Cosmetic Directive (76/768/EEC) and recast Regulation now bans marketing of new cosmetics having animal testing of their ingredients and requires non-animal alternative tests for safety assessments. Thus, in silico and/or in vitro tests are advocated. QSAR models for eye irritation have been reported for several small (congeneric) data sets; however, large global models have not been described. This report describes FDA/CFSAN's development of 21 ANN c-QSAR models (QSAR-21) to predict eye irritation using the ADMET Predictor program and a diverse training data set of 2928 chemicals. The 21 models had external (20% test set) and internal validation and average training/verification/test set statistics were: 88/88/85(%) sensitivity and 82/82/82(%) specificity, respectively. The new method utilized multiple artificial neural network (ANN) molecular descriptor selection functionalities to maximize the applicability domain of the battery. The eye irritation models will be used to provide information to fill the critical data gaps for the safety assessment of cosmetic ingredient chemicals. PMID:25497990

  12. Protection of environmental contamination by radioactive materials and remediation of environment

    This report consisted of the environmental contamination of radioactive and non-radioactive materials. 38 important accident examples of environmental contamination of radioactive materials in the world from 1944 to 2001 are stated. Heavily polluted areas by accidents are explained, for example, Chernobyl, atomic reactor accidents, development of nuclear weapon in USA and USSR, radioactive waste in the sea. The environmental contamination ability caused by using radioactive materials, medical use, operating reactor, disposal, transferring, crashing of airplane and artificial satellite, release are reported. It contains measurements and monitor technologies, remediation technologies of environmental contamination and separation and transmutation of radioactive materials. On the environmental contamination by non-radioactive materials, transformation of the soil contamination in Japan and its control technologies are explained. Protection and countermeasure of environmental contamination of radioactive and non-radioactive materials in Japan and the international organs are presented. There are summary and proposal in the seventh chapter. (S.Y.)

  13. Monitoring of radioactivity in the marine environment

    The necessity of radioactivity monitoring in the marine environment was imposed by the increasing development of nuclear power and its world-wide use in many different segments of economic and social life. Both natural and artificial radioactivity play an important role in marine ecology and human health. In this respect three major facts continue to prevail in Romania. The fallout, the presence of the Danube river and the expectations for future energy production. Spatial and temporal monitoring of marine radioactivity along the Romanian Black Sea shore has been systematically performed in the Romanian Marine Research Institute in close co-operation with the Institute of Meteorology and Hydrology since 1981. Marine emerged and submerged sediments, coastal and offshore sea water, macroalgae, in vertebrates and fish off the Danube mouths and/or along the coast are monitored for natural and artificial radioactivity by means of beta gross measurements and gamma spectrometry. Concentrations of radionuclides as K-40, Cs-134, Cs-137 in abiotic and biotic samples, environmental distributions coefficients and concentrations factors (CF), as well as experimentally-derived CFs in marine biota as radioecological bioindicators are assessed and stored for a national data base. (author) 3 tabs., 18 refs

  14. Distribution of radioactive constituents in river waters

    For a research project on the distribution and evaluation of natural and artificial radioactive constituents in ecological segments of Biscay (northeast spain), the amounts of nuclides present in the main river waters were measured. Radioactive procedures include i) total alpha and beta indexes with a gas flow detector, dry residues near to 2 and 10 mg/ cm sup 2, respectively and counting periods of 1000 mn, ii) gamma emitters with a low level gamma spectrometer (Ge-HP detector + 8000 channels analyser) using the dry residue from 8 litres and a counting period of 4 days and iii) statistical treatment of data at 95% confidence.In this paper, ten water samples from the nervion river basin are included. Physical and chemical parameters of samples were also determined by standard procedures, because there is a sharp change in the composition of this river in the first part of the course. Radioactive constituents were identified as follows: a sample has a detectable alpha index, all samples contains beta emitters with a high variability, natural nuclides from uranium and thorium families were detected in some cases. A parallel behaviour is found between samples where K-40 and Cs-137 were found. The paper tries at last to find relations among chemical and radioactive constituents by the application of multivariate statistical methods, specially for the case of Cs-137, the only artificial nuclide identified in this work. 1 tab., 2 figs., 5 refs. (author)

  15. Radioactive monitoring of the marine environment

    Radioactivity monitoring of marine environment was required by the development of nuclear power and the worldwide use of ionizing radiations in many different activities. Both natural and artificial radioactivity play an important role in marine ecology and human health. In respect of this, three major facts prevail, namely: the fallout, the proximity of Danube River and the future nuclear power production. Spatial and temporal monitoring of marine radioactivity along the Romanian Black Sea shore has been systematically performed in Romanian Marine Research Institute in close cooperation with Institute of Meteorology and Hydrology since 1981. Marine emerged and submerged sediments, coastal and offshore sea water, macroalgae, invertebrates and fish of Danube mouths and/or along the coast are monitored for natural and artificial radioactivity by means of gross beta measurements and gamma spectrometry. Concentrations of radionuclides such as: K-40, Cs-134 and Cs-137 in abiotic and biotic samples, environmental distribution coefficients and concentration factors (CFs) as well as experimentally derived CFs in marine biota as radioecological bioindicators are assessed and stored in a national data base. (author)

  16. Radioactivity and Nuclear Issues in Science Fiction

    In this work are presented and reviewed science fiction narratives, films and comics that exploit radioactivity and nuclear issues. These topics to some science fiction authors serve as metaphor of evil and holocaust as well as nice instrument for elaborating various manipulations and conspiracy theories. In that context are of special interest science fiction works depicting apocalyptic post-nuclear worlds and societies, such works being closely connected with cyberpunk genre. However, other more technologically optimistic authors nuclear energy and research regarding nuclear technology and radioactivity consider as eligible and inevitable solution for world peace and prosperity Nowadays, public interest and global fears are shifted from radioactivity and nuclear issues to other catastrophic scenarios threatening future of the mankind, these for example being climate changes and global warming, asteroid impact, collapse of information infrastructure, nanotechnology, robotics and artificial intelligence etc. Consequently, these issues are as well increasingly reflected in contemporary science fiction stories.(author)

  17. Radiation protection. Radioactivity and health. 3. ed.

    This booklet makes an attempt at elucidating the mutual influence of radioactivity and health in a way which is understandable to the non-expert. The basics of radioactivity are briefly explained by way of introduction, the next item to be described is exposure of man to natural and artificial radiation. Somatic and genetic effects of radiation on man are subsequently discussed. The whole area of radioecology - starting with radioactive discharge from nuclear plants and going on to the determination of man's exposure to radiation - is covered and supplemented by a description of the risks of radiation therapy. All this serves to describe the results of long-term research on questions of the radiobiological risks in an understandable way and provide useful information about this eminently important area. (orig.)

  18. Penetration by artificial electron acceptors of the plasma membrane-bound redox system into intact Zea mays L. roots investigated by proton-induced X-ray emission

    Proton-induced X-ray emission was used to investigate the penetration of compounds of the membrane-impermeant electron acceptors hexabromoiridate IV, hexachloroiridate IV, and hexacyanoferrate III into corn (Zea mays L.) roots. Maps of the heavy element distribution in cross-sections of fixed, epoxy-embedded roots showed for hexabromoiridate IV small amounts of Br in samples treated for 24 h with concentrations normally used in physiological experiments (0.02 mM). After treatment with high concentrations (0.8 mM) of these complexes, Fe and Ir as well as Br were found in root cross-sections. In samples taken at a distance of 5 mm behind the root tip, we found an even distribution of Fe, Ir, and Br over the whole cross-section. In samples taken 15 mm behind the root tip, about 99% of both Br and Ir was confined to the rhizodermal cell layer. The distribution did not change with the complex used. These data are consistent with the view that apoplastic diffusion of the electron acceptors was blocked by the hypodermal Casparian band

  19. Molecular characterization of three GnRH receptor paralogs in the European eel, Anguilla anguilla: tissue-distribution and changes in transcript abundance during artificially induced sexual development.

    Peñaranda, David S; Mazzeo, Ilaria; Hildahl, Jon; Gallego, Victor; Nourizadeh-Lillabadi, Rasoul; Pérez, Luz; Asturiano, Juan F; Weltzien, Finn-Arne

    2013-04-30

    Gonadotropin-releasing hormone receptor (GnRH-R) activation stimulates synthesis and release of gonadotropins in the vertebrate pituitary and also mediates other processes both in the brain and in peripheral tissues. To better understand the differential function of multiple GnRH-R paralogs, three GnRH-R genes (gnrhr1a, 1b, and 2) were isolated and characterized in the European eel. All three gnrhr genes were expressed in the brain and pituitary of pre-pubertal eels, and also in several peripheral tissues, notably gills and kidneys. During hormonally induced sexual maturation, pituitary expression of gnrhr1a (female) and gnrhr2 (male and female) was up-regulated in parallel with gonad development. In the brain, a clear regulation during maturation was seen only for gnrhr2 in the midbrain, with highest levels recorded during early vitellogenesis. These data suggest that GnRH-R2 is the likely hypophysiotropic GnRH-R in male eel, while both GnRH-R1a and GnRH-R2 seems to play this role in female eels. PMID:23416230

  20. Transport of radioactive substances

    The report on the transport of radioactive substances covers the following topics: facts on radioactive materials transport, safety of the transport of radioactive substances, legal regulations and guidelines: a multiform but consistent system, transport of nuclear fuels, safety during the transport of nuclear fuel, future transport of spent fuel elements and high-level radioactive wastes in Germany.

  1. Radioactive pollution

    The widely published claims that the public health effects resulting from routine emissions are between 0.01 and 0.1 serious health effects per gigawattyear, and hence are at least a thousand times smaller than those resulting from air pollution by the burning of coal, cannot be true, for two reasons. The authors of these claims have ignored at least two of the more important isotopes, radon-222 and carbon-14, which are presently released to the environment, and thus contribute greatly to the health impact of nuclear energy. The health effects calculated in the earlier work cover only those which occur during the year in which the energy is generated. This means, figuratively speaking, that the authors have confused an annual installment payment with the full cost. This is unacceptable. The contribution to the health impact of nuclear energy arising from the single isotopic species radon-222 emanating from the mill tailings is estimated to 400 lung cancer deaths/GW(e)y, larger even than the most pessimistic estimates of the health impact of energy from coal through atmospheric pollution. We have no assurance that other long-lived isotopes do not contribute comparable amounts to the health impact of nuclear energy. The discussion of the health impact of radon-222 raises the fundamental moral question--how far into the future our responsibility extends. If such a long-termresponsibility is rejected, then we must at least try to predict the environmental buildup of radioactive pollutants, in order to avoid unacceptable and irreversible levels of radiation dose rate. The potential health consequences from long-lived radioisotopes seem to have been largely ignored so far, and should be explored in detail

  2. Production of artificial radioelements

    The techniques used in the production of artificial radioelements are described, with special emphasis on the following points: - nuclear reactions and use of reactors; - chemical separation methods and methods for enriching the activity of preparations; - protection of personnel and handling methods. (author)

  3. Micromachined Artificial Haircell

    Liu, Chang (Inventor); Engel, Jonathan (Inventor); Chen, Nannan (Inventor); Chen, Jack (Inventor)

    2010-01-01

    A micromachined artificial sensor comprises a support coupled to and movable with respect to a substrate. A polymer, high-aspect ratio cilia-like structure is disposed on and extends out-of-plane from the support. A strain detector is disposed with respect to the support to detect movement of the support.

  4. Artificial Gravity Research Plan

    Gilbert, Charlene

    2014-01-01

    This document describes the forward working plan to identify what countermeasure resources are needed for a vehicle with an artificial gravity module (intermittent centrifugation) and what Countermeasure Resources are needed for a rotating transit vehicle (continuous centrifugation) to minimize the effects of microgravity to Mars Exploration crewmembers.

  5. Artificial limb connection

    Owens, L. J.

    1974-01-01

    Connection simplifies and eases donning and removing artificial limb; eliminates harnesses and clamps; and reduces skin pressures by allowing bone to carry all tensile and part of compressive loads between prosthesis and stump. Because connection is modular, it is easily modified to suit individual needs.

  6. Artificial joint lubrication

    Pražák, Josef; Štol, Miroslav; Musil, Jan

    Olomouc : Palacký University, 2000 - (Vaverka, F.; Janura, M.), s. 118-119 ISBN 80-244-0193-2. [Conference of the Czech Society of biomechanics with international participation Biomechanics of man 2000. Olomouc (CZ), 24.11.2000-25.11.2000] R&D Projects: GA MPO FB/64/98 SKELET Keywords : lubrication * synovial fluid * artificial joints Subject RIV: CE - Biochemistry

  7. Observations of artificial satellites

    A. MAMMANO

    1964-06-01

    Full Text Available The following publication gives the results of photographic
    observations of artificial satellites made at Asiago during the second
    and third year of this programme. The fixed camera technique and that
    with moving film (the latter still in its experimental stage have been used.

  8. Natural or Artificial Intelligence?

    Havlík, Vladimír

    Plzeň : University of West Bohemia, 2013 - (Romportl, J.; Ircing, P.; Zackova, E.; Polak, M.; Schuster, R.), s. 15-27 ISBN 978-80-261-0275-5. [International Conference Beyond AI 2013. Plzeň (CZ), 12.11.2013-14.11.2013] Institutional support: RVO:67985955 Keywords : artificial intelligence * natural intelligence * artifact * natural process * intrinsic intentionality Subject RIV: AA - Philosophy ; Religion

  9. Artificial intelligence within AFSC

    Gersh, Mark A.

    1990-01-01

    Information on artificial intelligence research in the Air Force Systems Command is given in viewgraph form. Specific research that is being conducted at the Rome Air Development Center, the Space Technology Center, the Human Resources Laboratory, the Armstrong Aerospace Medical Research Laboratory, the Armamant Laboratory, and the Wright Research and Development Center is noted.

  10. Artificial Intelligence and CALL.

    Underwood, John H.

    The potential application of artificial intelligence (AI) to computer-assisted language learning (CALL) is explored. Two areas of AI that hold particular interest to those who deal with language meaning--knowledge representation and expert systems, and natural-language processing--are described and examples of each are presented. AI contribution…

  11. Artificial binary data scenarios

    Dolnicar, Sara; Leisch, Friedrich; Weingessel, Andreas

    1998-01-01

    This manual describes artificial binary data scenarios. These data sets can be used to compare the performance of algorithms for market segmentation. The data sets described in this manual are available as packages for R (Splus) and as ASCII-files under htttp://www.ci.tuwien.ac.at/SFB/. (author's abstract)

  12. Terahertz Artificial Dielectric Lens

    Mendis, Rajind; Nagai, Masaya; Wang, Yiqiu; Karl, Nicholas; Mittleman, Daniel M.

    2016-01-01

    We have designed, fabricated, and experimentally characterized a lens for the THz regime based on artificial dielectrics. These are man-made media that mimic properties of naturally occurring dielectric media, or even manifest properties that cannot generally occur in nature. For example, the well-known dielectric property, the refractive index, which usually has a value greater than unity, can have a value less than unity in an artificial dielectric. For our lens, the artificial-dielectric medium is made up of a parallel stack of 100 μm thick metal plates that form an array of parallel-plate waveguides. The convergent lens has a plano-concave geometry, in contrast to conventional dielectric lenses. Our results demonstrate that this lens is capable of focusing a 2 cm diameter beam to a spot size of 4 mm, at the design frequency of 0.17 THz. The results further demonstrate that the overall power transmission of the lens can be better than certain conventional dielectric lenses commonly used in the THz regime. Intriguingly, we also observe that under certain conditions, the lens boundary demarcated by the discontinuous plate edges actually resembles a smooth continuous surface. These results highlight the importance of this artificial-dielectric technology for the development of future THz-wave devices. PMID:26973294

  13. Artificial Left Ventricle

    Ranjbar, Saeed; Meybodi, Mahmood Emami

    2014-01-01

    This Artificial left ventricle is based on a simple conic assumption shape for left ventricle where its motion is made by attached compressed elastic tubes to its walls which are regarded to electrical points at each nodal .This compressed tubes are playing the role of myofibers in the myocardium of the left ventricle. These elastic tubes have helical shapes and are transacting on these helical bands dynamically. At this invention we give an algorithm of this artificial left ventricle construction that of course the effect of the blood flow in LV is observed with making beneficiary used of sensors to obtain this effecting, something like to lifegates problem. The main problem is to evaluate powers that are interacted between elastic body (left ventricle) and fluid (blood). The main goal of this invention is to show that artificial heart is not just a pump, but mechanical modeling of LV wall and its interaction with blood in it (blood movement modeling) can introduce an artificial heart closed to natural heart...

  14. Argumentation in Artificial Intelligence

    Simari, Guillermo

    2009-01-01

    Examines the intersection between two fields of inquiry, including Argumentation Theory and Artificial Intelligence. This book presents an overview of key concepts in argumentation theory and of formal models of argumentation in AI. It offers a review of the foundational issues in argumentation and formal argument modeling.

  15. On the modification of nuclear chronometry methods in astrophysics and geophysics induced by excited states of alpha radioactive nuclei and gamma emission

    In practically all methods of nuclear chronometry known till now, were the lifetimes of only fundamental states for decaying α-radioactive nuclei usually taken into account. But in the processes of nuclear synthesis in stars and under the influence of the constant cosmic radiation on the surfaces of planets, also the excited α-radioactive nuclei appear. Between them, there are the states with the excited α-particles inside the parent nuclei. They have much smaller lifetimes relative to the Geiger and Nutall law. And inside the large masses of stellar, terrestrial and meteoric substances, the transitions between different excited radioactive nuclei are accompanied by infinite chains of the γ-radiations with the subsequent γ-absorptions, the further γ-radiations etc. We must describe the α-decay evolution, considering such excited states and multiple γ-radiations and γ-absorptions inside stars and also under the influence of the cosmic radiation on the earth surface. We present the quantum-mechanical approach, which is based on the generalized Krylov–Fock theorem. Some simple estimations are presented. They give rise to the conclusion that the usual (non-corrected) "nuclear clocks" do not really indicate the realistic values but the upper limits of the durations of the α-decay stellar and planet processes. (author)

  16. Introduction to Artificial Neural Networks

    Larsen, Jan

    1999-01-01

    The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks.......The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks....

  17. Inflatable artificial sphincter - series (image)

    An artificial urinary sphincter is used to treat stress incontinence in men that is caused by urethral dysfunction such ... An artificial sphincter consists of three parts: a cuff that fits around the bladder neck a pressure regulating balloon ...

  18. Application of biotechnology to the problem of the disposal of radioactive wastes

    Artificial biological systems are proposed for use in the treatment of low- and intermediate-level radioactive wastes. The microbial conversion of organic and inorganic substances under continuous conditions, involving the turnover of matter, will allow a significant reduction in volume of radioactive wastes. Such specialised systems can act as a biogeochemical barrier for radionuclide transport. 14 refs

  19. Survey monitoring of environmental radioactivity in Daejeon area

    Jun, Jae Sik; Noh, Hyung Ah [Daejon Radiation Monitoring Station, Daejeon (Korea, Republic of)

    2001-12-15

    Systematic understanding of the distribution of environmental radioactivity and radiation level in Daejeon, including Chungchung area, in normal circumstance, and rapid detection of unusual variation of the radiation level in emergency situation thereby ensure public safety are the objectives of this project to be carried out. This report summarizes and interprets environmental radiation/radioactivity monitoring data obtained at Daejeon Radiation Monitoring Station in 2001. In conclusion, the natural environmental radiation level in Daejeon area has been preserved as usual and no significant artificial enhancement in environmental radioactivity was observed during the course of this survey and monitoring period.

  20. Radioactive characterization of sand samples from Failaka Island in Kuwait

    Sand samples were collected from Failaka Island in the state of Kuwait for radioactive characterization. The activity concentrations of both natural and artificial radionuclides were determined using gamma (γ)-ray spectrometry. From the measured γ-spectra, radioactivity concentrations were determined for Uranium-238 (238U), Thorium-232 (232Th), Radium-226 (226Ra), Potassium-40 (40K), and Cesium-137 (137Cs). To evaluate the radiological hazard of the natural radioactivity on Failaka Island, the radium equivalent activity, the representative level index, the external hazard index, the internal hazard index, the absorbed dose, and the effective dose rate were calculated and compared with international approved values. (author)